CommonWealth REIT (Form: 8-K, Received: 05/31/2011 16:54:09)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): May 26, 2011 (May 26, 2011)

COMMONWEALTH REIT

(Exact Name of Registrant as Specified in Its Charter)

Maryland		1-9317		04-6558834
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(I.R.S. Employer Identification No.)

Two Newton Place, 255 Washington Street, Suite 300, Newton, MA 02458

(Address of Principal Executive Offices) (Zip Code)

617-332-3990

(Registrant’s Telephone Number, Including Area Code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 5.03. Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On May 31, 2011, CommonWealth REIT, or we, us or our, filed Articles Supplementary to our declaration of trust creating a new series of preferred shares, 7 1 / 4 % Series E Cumulative Redeemable Preferred Shares, $0.01 par value per share, or the Series E Preferred Shares. The Articles Supplementary were effective upon filing. Further information regarding the Series E Preferred Shares appears below under the caption “Item 8.01. Other Events”.

Item 8.01. Other Events.

On May 26, 2011, we agreed to issue 10,000,000 of the Series E Preferred Shares in an underwritten public offering. We expect to issue and deliver these shares on or about June 1, 2011. The price to the public will be $25 per share, plus accrued distributions, if any, from the date of original issuance. We estimate the net proceeds from the sale of the Series E Preferred Shares (assuming no exercise of the underwriters’ overallotment option, as described below), after the underwriting discount and other estimated expenses of the offering payable by us, will be $241.6 million. We expect to use the net proceeds to reduce amounts outstanding under our revolving credit facility and for general business purposes, including future acquisitions. We also granted the underwriters a 30-day option to purchase up to an additional 1,500,000 Series E Preferred Shares to cover overallotments, if any.

The following is a summary of the material terms of the Series E Preferred Shares. Because it is a summary, it does not contain all of the information that may be important to you. If you want more information, you should read our declaration of trust, the Articles Supplementary to our declaration of trust relating to the Series E Preferred Shares and our bylaws. A copy of those Articles Supplementary is filed as an exhibit to this Current Report on Form 8-K and incorporated herein by reference. Copies of our declaration of trust and our bylaws are filed as exhibits to other filings we have made with the Securities and Exchange Commission, or SEC. Our filings with the SEC are available at the SEC’s website: www.sec.gov.

Holders of Series E Preferred Shares are entitled to receive cumulative cash distributions at a rate of 7 1 / 4 % per year of the $25 per share liquidation preference (equivalent to $1.8125 per year per share). Distributions on the Series E Preferred Shares are payable quarterly in arrears on the 15th day of each February, May, August and November, or, if not a business day, the next business day, beginning August 15, 2011. Distributions on the Series E Preferred Shares are cumulative. The Series E Preferred Shares rank senior to our common shares and our junior participating preferred shares with respect to the payment of dividends and on a parity with our 7 1 / 8 % Series C cumulative redeemable preferred shares, or the Series C Preferred Shares, our 6 1 / 2 % Series D cumulative convertible preferred shares, or the Series D Preferred Shares, and any other series of our preferred shares or other equity securities that we may later authorize and that by their terms are on a parity with the Series E Preferred Shares with respect to distribution rights or payments upon our liquidation, dissolution or winding up.

The Series E Preferred Shares do not have any maturity date, and we are not required to redeem the Series E Preferred Shares. We may not redeem the Series E Preferred Shares prior to May 15, 2016, except in limited circumstances relating to our continuing qualification as a real estate investment trust and except pursuant to our special redemption right in connection with a Change of Control summarized below. On and after May 15, 2016, we may, at our option,

redeem the Series E Preferred Shares, in whole or from time to time in part, by payment of $25 per share, plus accrued and unpaid distributions through and including the date of redemption. Upon the occurrence of a Change of Control, we may, at our option, redeem the Series E Preferred Shares, in whole or in part, by payment of $25 per share, plus any accrued and unpaid distributions to but excluding the date of redemption.

Upon the occurrence of a Change of Control, each holder of Series E Preferred Shares will have the right (unless, prior to the Change of Control Conversion Date described below, we have provided notice of our election to redeem the Series E Preferred Shares) to convert some or all of the Series E Preferred Shares held by such holder, or the Change of Control Conversion Right, on the Change of Control Conversion Date into a number of our common shares per Series E Preferred Share to be converted equal to the lesser of:

· the quotient obtained by dividing (i) the sum of the $25.00 liquidation preference plus the amount of any accrued unpaid distributions to but excluding the Change Control Conversion Date (unless the Change of Control Conversion Date is after a record date for a Series E Preferred Share distribution payment and prior to the corresponding Series E Preferred Share distribution payment date, in which case no additional amount for accrued and unpaid distribution will be included in this sum) by (ii) the Common Share Price (as described below); and

· a share cap equal to 1.967, subject to adjustments in certain circumstances;

subject, in each case, to provisions for the receipt of alternative consideration as described in the Articles Supplementary. The Series E Preferred Shares are not otherwise convertible into or exchangeable for any other securities or property.

A “Change of Control” is when the following have occurred and are continuing:

· the acquisition by any person, including any syndicate or group deemed to be a “person” under Section 13(d)(3) of the Securities Exchange Act of 1934, as amended, of beneficial ownership, directly or indirectly, through a purchase, merger or other acquisition transaction or series of purchases, mergers or other acquisition transactions of our shares entitling that person to exercise more than 50% of the total voting power of our shares entitled to vote generally in elections of trustees (except that such person will be deemed to have beneficial ownership of all securities that such person has the right to acquire, whether such right is currently exercisable or is exercisable only upon the occurrence of a subsequent condition); and

· following the closing of any transaction referred to in the bullet point above, neither we nor the acquiring or surviving entity has a class of common securities (or American Depositary Receipts representing such securities) listed on the New York Stock Exchange, or the NYSE, the NYSE Amex Equities, or the NYSE Amex, or the NASDAQ Stock Market, or NASDAQ, or listed or quoted on an exchange or quotation system that is a successor to the NYSE, the NYSE Amex or NASDAQ.

The “Change of Control Conversion Date” is a business day, stated in the notice of the occurrence of a Change of Control we are required to provide to the holders of Series E Preferred Shares, that is no fewer than 20 days nor more than 35 days after the date of that notice.

The “Common Share Price” will be: (i) the amount of cash consideration per common share, if the consideration to be received in the Change of Control by the holders of our common shares is solely cash; and (ii) the average of the closing prices for our common shares on the NYSE for the ten consecutive trading days immediately preceding but excluding the effective date of the Change of Control, if the consideration to be received in the Change of Control by the holders of the our common shares is other than solely cash.

The Change of Control conversion and redemption features of the Series E Preferred Shares may make it more difficult for a party to take us over or discourage a party from taking us over.

If we liquidate, dissolve or wind up, holders of the Series E Preferred Shares will have the right to receive $25 per share, plus accrued and unpaid distributions through the date of payment, before any payments are made to the holders of our common shares and any other shares of beneficial interest ranking junior to the Series E Preferred Shares as to liquidation rights. The rights of the holders of the Series E Preferred Shares to receive their liquidation preference will be subject to the proportionate rights of each other series or class of shares ranking on a parity with the Series E Preferred Shares, including our Series C Preferred Shares and Series D Preferred Shares.

Holders of any series of our preferred shares, including the Series E Preferred Shares, generally have no voting rights. However, if at any time distributions on the Series E Preferred Shares are in arrears for six quarterly periods, whether or not these quarterly periods are consecutive, holders of our Series E Preferred Shares, voting together with all other series of preferred shares which have similar voting rights, including our Series C Preferred Shares and our Series D Preferred Shares, will be entitled to elect two additional trustees to our board of trustees at the next annual meeting of shareholders and at each subsequent annual meeting until until we declare or pay and set aside for payment all distributions accrued and unpaid on the Series E Preferred Shares. In addition, the affirmative vote of the holders of at least two-thirds of the Series E Preferred Shares is required for us:

· to authorize, create or increase the authorized or issued amount of any class or series of shares of beneficial interest ranking senior to the Series E Preferred Shares with respect to distribution and liquidation rights;

· to reclassify any authorized shares of beneficial interest into a series of shares of beneficial interest ranking senior to the Series E Preferred Shares with respect to distribution and liquidation rights;

· to create, authorize or issue any security or obligation convertible into or evidencing the right to purchase any shares of beneficial interest ranking senior to the Series E Preferred Shares with respect to distribution and liquidation rights; and

· to amend, alter or repeal the provisions of our declaration of trust or the articles supplementary relating to the Series E Preferred Shares, whether by merger, consolidation or otherwise, that materially and adversely affects the Series E Preferred Shares.

The authorization, creation or increase of the authorized or issued amount of any class or series of shares of beneficial interest ranking on parity or junior to the Series E Preferred Shares with respect to distribution and liquidation rights will not be deemed to materially and adversely affect the Series E Preferred Shares. Further, with respect to any merger, consolidation or similar event, so long as the Series E Preferred Shares remain outstanding with the terms thereof materially unchanged or the holders of shares of Series E Preferred Shares receive shares of the successor with substantially identical rights, taking into account that, upon the occurrence of such event, we may not be the surviving entity, the occurrence of such event will not be deemed to materially and adversely affect the Series E Preferred Shares. In any matter in which the Series E Preferred Shares are entitled to vote, each Series E Preferred Share will be entitled to one vote. If the holders of Series E Preferred Shares and another series of preferred shares are entitled to vote together as a single class on any matter, the Series E Preferred Shares and the shares of the other series will have one vote for each $25.00 of liquidation preference.

A prospectus supplement relating to the Series E Preferred Shares will be filed with the Securities and Exchange Commission. This Current Report on Form 8-K shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

WARNING REGARDING FORWARD LOOKING STATEMENTS

THIS CURRENT REPORT ON FORM 8-K CONTAINS FORWARD LOOKING STATEMENTS WITHIN THE MEANING OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995 AND OTHER FEDERAL SECURITIES LAWS. THESE FORWARD LOOKING STATEMENTS ARE BASED UPON OUR PRESENT EXPECTATIONS, BUT THESE STATEMENTS ARE NOT GUARANTEED. FOR EXAMPLE,

· THIS CURRENT REPORT ON FORM 8-K STATES THAT THE ISSUANCE AND DELIVERY OF SERIES E PREFERRED SHARES IS EXPECTED TO OCCUR ON JUNE 1, 2011. IN FACT, THE SETTLEMENT OF THIS OFFERING IS SUBJECT TO VARIOUS CONDITIONS AND CONTINGENCIES AS ARE CUSTOMARY IN UNDERWRITING AGREEMENTS IN THE UNITED STATES. IF THESE CONDITIONS ARE NOT SATISFIED OR THE SPECIFIED CONTINGENCIES DO NOT OCCUR, THIS OFFERING MAY NOT CLOSE.

· THIS CURRENT REPORT ON FORM 8-K STATES THAT THE UNDERWRITERS HAVE BEEN GRANTED A 30-DAY OPTION TO PURCHASE ADDITIONAL SHARES TO COVER OVER ALLOTMENTS, IF ANY. AN IMPLICATION OF THIS STATEMENT MAY BE THAT THIS OPTION MAY BE EXERCISED IN WHOLE OR IN PART. IN FACT, WE DO NOT KNOW

WHETHER THE UNDERWRITERS WILL EXERCISE THIS OPTION, OR ANY PART OF IT.

FOR THESE REASONS, AMONG OTHERS, INVESTORS SHOULD NOT PLACE UNDUE RELIANCE UPON ANY FORWARD LOOKING STATEMENT.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

We hereby file the following exhibits:

1.1		Purchase Agreement, dated as of May 26, 2011, between CommonWealth REIT and the underwriters named therein, pertaining to the sale of up to 10,000,000 of CommonWealth REIT’s 7 1 / 4 % Series E Cumulative Redeemable Preferred Shares.

3.1		Articles Supplementary, dated May 31, 2011.

4.1		Form of 7 1 / 4 % Series E Cumulative Redeemable Preferred Share Certificate.

5.1		Opinion of Venable LLP.

8.1		Opinion of Sullivan & Worcester LLP as to tax matters.

23.1		Consent of Venable LLP (contained in Exhibit 5.1).

23.2		Consent of Sullivan & Worcester LLP (contained in Exhibit 8.1).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	COMMONWEALTH REIT

	By:	/s/ John C. Popeo
		John C. Popeo
		Treasurer and Chief Financial Officer
		Date: May 26, 2011

Exhibit 1.1

Execution Copy

10,000,000 Shares

COMMONWEALTH REIT

(a Maryland real estate investment trust)

7¼% Series E Cumulative Redeemable Preferred Shares
(Liquidation Preference $25.00 Per Share)

PURCHASE AGREEMENT

May 26, 2011

Merrill Lynch, Pierce, Fenner & Smith

Incorporated
Citigroup Global Markets Inc.

UBS Securities LLC
Wells Fargo Securities, LLC

as Representatives of the several Underwriters

c/o Merrill Lynch, Pierce, Fenner & Smith

Incorporated

One Bryant Park
New York, New York 10036

Ladies and Gentlemen:

CommonWealth REIT, a Maryland real estate investment trust (the “Company”), confirms its agreement with Merrill Lynch, Pierce, Fenner & Smith Incorporated (“Merrill Lynch”), Citigroup Global Markets Inc. (“Citi”), UBS Securities LLC (“UBS”) and Wells Fargo Securities, LLC (“Wells Fargo Securities”) and each of the other Underwriters named in Schedule A hereto (collectively, the “Underwriters” which term shall also include any underwriter substituted as hereinafter provided in Section 10 hereof), for whom Merrill Lynch, Citi, UBS and Wells Fargo Securities are acting as representatives (in such capacity, the “Representatives”), with respect to the issuance and sale by the Company and the purchase by the Underwriters, acting severally and not jointly, of the respective numbers of 7¼% Series E Cumulative Redeemable Preferred Shares (liquidation preference $25.00 per share), par value $.01 per share, of the Company (the “Series E Shares”) set forth in said Schedule A and with respect to the grant by the Company to the Underwriters, acting severally and not jointly, of the option described in Section 2(b) hereof to purchase all or any part of an additional 1,500,000

Series E Shares to cover overallotments, if any. The aforesaid 10,000,000 Series E Shares (the “Initial Shares”) to be purchased by the Underwriters and all or any part of the 1,500,000 Series E Shares subject to the option described in Section 2(b) hereof (the “Option Shares”), are hereinafter called, collectively, the “Preferred Shares.”

The Company understands that the Underwriters propose to make a public offering of the Preferred Shares as soon as the Representatives deem advisable after this Agreement has been executed and delivered.

The Company has filed with the Securities and Exchange Commission (the “Commission”) an automatic shelf registration statement on Form S-3 (No. 333-159995), including the related prospectus, which registration statement became effective upon filing under Rule 462(e) of the rules and regulations of the Commission (the “1933 Act Regulations”) under the Securities Act of 1933, as amended (the “1933 Act”). Such registration statement covers the registration of the Preferred Shares under the 1933 Act. Promptly after execution and delivery of this Agreement, the Company will prepare and file a prospectus in accordance with the provisions of Rule 430B (“Rule 430B”) of the 1933 Act Regulations and paragraph (b) of Rule 424 (“Rule 424(b)”) of the 1933 Act Regulations. Any information included in such prospectus that was omitted from such registration statement at the time it became effective but that is deemed to be part of and included in such registration statement pursuant to Rule 430B is referred to as “Rule 430B Information.” Each prospectus used in connection with the offering of the Preferred Shares that omitted Rule 430B Information is herein called a “preliminary prospectus.” Such registration statement, at any given time, including the amendments thereto at such time, the exhibits and any schedules thereto at such time, the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the 1933 Act at such time and the documents otherwise deemed to be a part thereof or included therein by the 1933 Act Regulations, is herein called the “Registration Statement.” The Registration Statement at the time it originally became effective is herein called the “Original Registration Statement.” The final prospectus in the form first furnished to the Underwriters for use in connection with the offering of the Preferred Shares, including the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the 1933 Act at the time of the execution of this Agreement, is herein called the “Prospectus.” For purposes of this Agreement, all references to the Registration Statement, any preliminary prospectus, the Prospectus or any amendment or supplement to any of the foregoing shall be deemed to include the copy filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval system (“EDGAR”).

All references in this Agreement to financial statements and schedules and other information which is “contained”, “included” or “stated” in the Registration Statement, any preliminary prospectus or the Prospectus or the General Disclosure Package (as defined herein) , or other references of like import, shall be deemed to mean and include all such financial statements and schedules and other information which is incorporated by reference in or otherwise deemed by the 1933 Act Regulations to be a part of or included in the Registration Statement, any preliminary prospectus or the Prospectus or the General Disclosure Package, as the case may be; and all references in this Agreement to amendments or supplements to the Registration Statement, any preliminary prospectus or the Prospectus or the General Disclosure Package shall be deemed to mean and include the filing of any document under the Securities Exchange Act of 1934, as amended (the “1934 Act”) which is incorporated by reference in or

otherwise deemed by the 1933 Act Regulations to be a part of or included in the Registration Statement, such preliminary prospectus or the Prospectus or the General Disclosure Package, as the case may be.

Section 1. Representations and Warranties .

(a) The Company represents and warrants to each Underwriter as of the date hereof, the Applicable Time referred to in Section 1(a)(ii) hereof, as of the Closing Time referred to in Section 2(c) hereof, and as of the Date of Delivery (if any) referred to in Section 2(b) hereof and agrees with each Underwriter, as follows:

(i) (A) At the time of filing the Original Registration Statement, (B) at the time of the most recent amendment thereto, if any, for the purposes of complying with Section 10(a)(3) of the 1933 Act (whether such amendment was by post-effective amendment, incorporated report filed pursuant to Section 13 or 15(d) of the 1934 Act or form of prospectus), (C) at the time the Company or any person acting on its behalf (within the meaning, for this clause only, of Rule 163(c) of the 1933 Act Regulations) made any offer relating to the Preferred Shares in reliance on the exemption provided by Rule 163 of the 1933 Act Regulations (“Rule 163”) and (D) at the date hereof, the Company was and is a “well-known seasoned issuer” as defined in Rule 405 of the 1933 Act Regulations (“Rule 405”), including not having been and not being an “ineligible issuer” as defined in Rule 405. The Registration Statement is an “automatic shelf registration statement,” as defined in Rule 405, and the Preferred Shares, since their registration on the Registration Statement, have been and remain eligible for registration by the Company on a Rule 405 “automatic shelf registration statement”. The Company has not received from the Commission any notice pursuant to Rule 401(g)(2) of the 1933 Act Regulations objecting to the use of the automatic shelf registration statement form.

At the time of filing the Original Registration Statement, at the earliest time thereafter that the Company or another offering participant made a bona fide offer (within the meaning of Rule 164(h)(2) of the 1933 Act Regulations) of the Preferred Shares and at the date hereof, the Company was not and is not an “ineligible issuer,” as defined in Rule 405.

(ii) The Original Registration Statement became effective upon filing under Rule 462(e) of the 1933 Act Regulations (“Rule 462(e)”) on June 15, 2009, and any post-effective amendment thereto also became effective upon filing under Rule 462(e). No stop order suspending the effectiveness of the Registration Statement has been issued under the 1933 Act and no proceedings for that purpose have been instituted or are pending or, to the knowledge of the Company, are contemplated by the Commission, and any request on the part of the Commission for additional information has been complied with.

Any offer that is a written communication relating to the Preferred Shares made prior to the filing of the Original Registration Statement by the Company or any person acting on its behalf (within the meaning, for this paragraph only, of Rule 163(c) of the 1933 Act Regulations) has been filed with the Commission in accordance with the exemption provided by Rule 163 and otherwise complied with the requirements of Rule

163, including without limitation the legending requirement, to qualify such offer for the exemption from Section 5(c) of the 1933 Act provided by Rule 163.

At the respective times the Original Registration Statement and any amendment thereto became effective, at each deemed effective date with respect to the Underwriters pursuant to Rule 430B(f)(2) of the 1933 Act Regulations and at the Closing Time, the Registration Statement complied and will comply in all material respects with the requirements of the 1933 Act and the 1933 Act Regulations, and did not and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading.

Neither the Prospectus nor any amendments or supplements thereto, at the time the Prospectus or any such amendment or supplement was issued and at the Closing Time and at the Date of Delivery (if any) referred to in Section 2(b) hereof, included or will include an untrue statement of a material fact or omitted or will omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

Each preliminary prospectus (including the prospectus or prospectuses filed as part of the Original Registration Statement or any amendment thereto) complied when so filed in all material respects with the 1933 Act Regulations and each preliminary prospectus and the Prospectus delivered to the Underwriters for use in connection with this offering was identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

As of the Applicable Time (as defined below), any Issuer Free Writing Prospectus (as defined below) issued at or prior to the Applicable Time, the Statutory Prospectus (as defined below) all considered together (collectively, the “General Disclosure Package”), did not include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

The representations and warranties in the preceding four paragraphs shall not apply to statements in or omissions from the Registration Statement or any post-effective amendment thereto, any preliminary prospectus, or the Prospectus or any amendments or supplements thereto, or the General Disclosure Package made in reliance upon and in conformity with information furnished to the Company in writing by the Representatives expressly for use in the Registration Statement (including the prospectus filed with the Original Registration Statement) or any post-effective amendment thereto, any preliminary prospectus, the Prospectus, or any amendments or supplements thereto, or the General Disclosure Package.

As used in this subsection and elsewhere in this Agreement:

“Applicable Time” means 3:05 P.M. (New York City time) on May 26, 2011 or such other time as agreed by the Company and the Representatives.

“Issuer Free Writing Prospectus” means any “issuer free writing prospectus,” as defined in Rule 433 of the 1933 Act Regulations (“Rule 433”), relating to the Preferred Shares (including those identified on Schedule B hereto) that (i) is required to be filed with the Commission by the Company, (ii) is a “road show that is a written communication” within the meaning of Rule 433(d)(8)(i), whether or not required to be filed with the Commission or (iii) is exempt from filing pursuant to Rule 433(d)(5)(i) because it contains a description of the Preferred Shares or of the offering that does not reflect the final terms, in each case in the form filed or required to be filed with the Commission or, if not required to be filed, in the form retained in the Company’s records pursuant to Rule 433(g).

“Statutory Prospectus” as of any time means the prospectus relating to the Preferred Shares that is included in the Registration Statement immediately prior to that time, including any document incorporated by reference therein and any preliminary or other prospectus deemed to be a part thereof.

(iii) The documents incorporated or deemed to be incorporated by reference in the Registration Statement, any preliminary prospectus and the Prospectus, at the time they were or hereafter are filed with the Commission, complied and will comply in all material respects with the requirements of the 1934 Act and the rules and regulations of the Commission under the 1934 Act (the “1934 Act Regulations”), as applicable, and, when read together with the other information in the Prospectus, (a) at the time the Registration Statement became effective, (b) at the earlier of the time the preliminary prospectus or the Prospectus was first used and the date and time of the first contract of sale of Preferred Shares in this offering and (c) at the Closing Time (and, if any Option Shares are purchased, at the Date of Delivery), did not and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(iv) Each Issuer Free Writing Prospectus attached to Schedule B hereto, as of its issue date and at all subsequent times through the completion of the public offer and sale of the Preferred Shares or until any earlier date that the Company notified or notifies the Representatives as described in Section 3(f), did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement or the Prospectus, including any document incorporated by reference therein and any preliminary or other prospectus deemed to be a part thereof that has not been superseded or modified. The foregoing sentence does not apply to statements in or omissions from any Issuer Free Writing Prospectus made in reliance upon and in conformity with information furnished to the Company in writing by the Representatives specifically for use therein.

(v) The Company is a Maryland real estate investment trust duly organized, validly existing and in good standing under the laws of the State of Maryland. Each of its subsidiaries has been duly organized and is validly existing as a corporation, partnership, limited liability company or trust in good standing under the laws of its jurisdiction of incorporation or organization, except where the failure to be in good standing would not have a material adverse effect on the Company and its subsidiaries, taken as a whole.

Each of the Company and its subsidiaries has full power and authority (corporate and other) to carry on its business as described in the Registration Statement, the General Disclosure Package and the Prospectus and to own, lease and operate its properties. Each of the Company and its subsidiaries is duly qualified and is in good standing as a foreign corporation, partnership, limited liability company or trust, as the case may be, and is authorized to do business in each jurisdiction in which the nature of its business or its ownership or leasing of property requires such qualification, except where the failure to be so qualified would not have a material adverse effect on the Company and its subsidiaries, taken as a whole. The Articles Supplementary relating to the Preferred Shares (the “Articles Supplementary”) will be in full force and effect as of the Closing Time.

(vi) The financial statements of the Company and its subsidiaries, together with the related schedules and notes thereto, included or incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus, comply as to form in all material respects with the requirements of the 1933 Act, the 1933 Act Regulations, the 1934 Act and the 1934 Act Regulations. Such financial statements of the Company, together with the related schedules and notes thereto, present fairly the consolidated financial position, results of operations, shareholders’ equity and changes in financial position of the Company and its subsidiaries, at the dates or for the respective periods therein specified and have been prepared in accordance with generally accepted accounting principles (“GAAP”) consistently applied throughout the periods involved. Any pro forma financial statements and other pro forma financial information (including the notes thereto) included or incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus (i) present fairly the information shown therein, (ii) have been prepared in accordance with the Commission’s rules and guidelines with respect to pro forma financial statements and (iii) have been properly compiled on the basis described therein and the assumptions used in the preparation of such pro forma financial statements and other pro forma financial information (including the notes thereto) are reasonable and the adjustments used therein are appropriate to give effect to the transactions or circumstances referred to therein. Any adjusted pro forma financial statements and other adjusted pro forma financial information (including the notes thereto) included or incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus (i) present fairly the information shown therein and (ii) have been properly compiled on the basis described therein and the assumptions used in the preparation of such adjusted pro forma financial statements and other adjusted pro forma financial information (including the notes thereto) are reasonable and the adjustments used therein are appropriate to give effect to the transactions or circumstances referred to therein. All disclosures contained in the Registration Statement, the General Disclosure Package and the Prospectus regarding “non-GAAP financial measures” (as such term is defined by the rules and regulations of the Commission) comply, in all material respects, with Regulation G of the 1934 Act and the 1934 Act Regulations and Item 10 of Regulation S-K under the 1933 Act, to the extent applicable.

(vii) The accounting firm that has certified the financial statements of the Company and its subsidiaries included or incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus is an independent

registered public accounting firm as required by the 1933 Act, the 1933 Act Regulations the 1934 Act, the 1934 Act Regulations and the Public Company Accounting Oversight Board (United States).

(viii) All of the outstanding shares of beneficial interest of the Company have been duly authorized and are validly issued, fully paid, non-assessable (except as otherwise described in the Registration Statement, the General Disclosure Package and the Prospectus) and free of preemptive or similar rights or other rights to subscribe for or to purchase securities provided for by law or by its Declaration of Trust or bylaws; the Preferred Shares to be issued and sold pursuant to this Agreement have been duly authorized and, when issued and delivered to the Underwriters against payment therefor as provided hereunder, will have been validly issued and will be fully paid, non-assessable (except as otherwise described in the Registration Statement, the General Disclosure Package and the Prospectus) and free of preemptive or similar rights; the Preferred Shares conform to the provisions of the Articles Supplementary; there are no outstanding subscriptions, rights, warrants, options, calls, convertible securities, commitments of sale or liens related to or entitling any person to purchase or otherwise to acquire any Preferred Shares or common shares of beneficial interest, par value $0.01 per share (the “Common Shares”) of, or other ownership interest in, the Company, except as otherwise disclosed in the Registration Statement, the General Disclosure Package and the Prospectus and except for awards under the Company’s Incentive Share Award Plan made in the ordinary course of business and shares issued to the Company’s external manager, Reit Management & Research LLC (the “Manager”) and its affiliates; all outstanding Common Shares, except for shares issued pursuant to the Company’s Incentive Share Award Plan and shares issued to the Manager and its affiliates, are listed on the New York Stock Exchange, Inc. (the “NYSE”) and the Company knows of no reason or set of facts which is likely to result in the delisting of such Common Shares or the inability to list the Preferred Shares; and there are no rights of holders of securities of the Company to the registration of Common Shares or other securities that would require inclusion of such Common Shares or other securities in the offering of the Preferred Shares.

(ix) The Common Shares issuable upon conversion of the Preferred Shares have been duly authorized and reserved for issuance upon such conversion by all necessary trust action and such shares, when issued upon such conversion in accordance with the terms of the Articles Supplementary, will be validly issued and will be fully paid and non-assessable and free of any preemptive or similar rights.

(x) This Agreement has been duly authorized, executed and delivered by the Company.

(xi) The authorized capital of the Company, including the Preferred Shares and the Common Shares, conforms as to legal matters to the description thereof contained in the Registration Statement, the General Disclosure Package and the Prospectus.

(xii) Since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package and the Prospectus, except as otherwise disclosed therein, (i) there has been no material adverse change in the business,

operations, earnings, prospects, properties or condition (financial or otherwise) of the Company and its subsidiaries, taken as a whole, whether or not arising in the ordinary course of business, (ii) there have been no material transactions entered into by the Company and its subsidiaries, on a consolidated basis, other than transactions in the ordinary course of business, (iii) neither the Company nor its subsidiaries have incurred any material liabilities or obligations, direct or contingent, and (iv) the Company and its subsidiaries, on a consolidated basis, have not, (A) other than regular quarterly dividends, declared, paid or made a dividend or distribution of any kind on any class of its shares of beneficial interest (other than dividends or distributions from wholly owned subsidiaries to the Company), (B) issued any shares of beneficial interest of the Company or any of its subsidiaries or any options, warrants, convertible securities or other rights to purchase the shares of beneficial interest of the Company or any of its subsidiaries (other than the issuance of (i) Common Shares to the trustees and officers of the Company and the directors, officers and employees of the Manager, pursuant to the Company’s Incentive Share Award Plan and (ii) Common Shares to the Manager in payment of its incentive fee and or (C) repurchased or redeemed shares of beneficial interest, and (v) there has not been (A) any material decrease in the Company’s net worth or (B) any material increase in the short - term or long - term debt (including capitalized lease obligations but excluding borrowings under existing bank lines of credit) of the Company and its subsidiaries, on a consolidated basis.

(xiii) The Company and each of its subsidiaries maintains a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(xiv) Neither the Company nor any of its subsidiaries is in violation of its respective declaration of trust, charter or by-laws or other organizational documents or in default in the performance of any obligation, agreement or condition contained in any bond, debenture, note or any other evidence of indebtedness or in any other agreement, indenture or instrument to which the Company or any of its subsidiaries is a party or by which any of their respective properties or assets may be bound or affected, except for any such violation that would not have a material adverse effect on the condition, financial or otherwise, or in the earnings, business, properties, operations or prospects of the Company and its subsidiaries, taken as a whole (a “Material Adverse Effect”). The Company is not in violation of any law, ordinance, governmental rule or regulation or court decree to which it is subject, except for any such violation that would not, individually or in the aggregate, have a Material Adverse Effect.

(xv) Except as disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, there is not now pending or, to the knowledge of the Company, threatened, any litigation, action, suit or proceeding to which the Company is or will be a party before or by any court or governmental agency or body, which (A) might result in any material adverse change in the condition, financial or otherwise, or in

the earnings, business affairs or business prospects of the Company and its subsidiaries, taken as a whole, or (B) might materially and adversely affect the property or assets of the Company and its subsidiaries, taken as a whole, or (C) concerns the Company and is required to be disclosed in the Registration Statement or the Prospectus, or (D) could adversely affect the consummation of the transaction contemplated by this Agreement and the issuance, purchase and sale of the Preferred Shares. No contract or other document is required to be described in the Registration Statement, the General Disclosure Package and the Prospectus or to be filed as an exhibit to the Registration Statement that is not described therein or filed as required.

(xvi) The execution, delivery and performance by the Company of this Agreement, the issuance, offering and sale by the Company of the Preferred Shares, the issuance of the Common Shares upon conversion of the Preferred Shares, as contemplated by the Registration Statement, the General Disclosure Package and the Prospectus and the consummation of the transactions contemplated hereby and compliance with the terms and provisions hereof, will not violate or conflict with or constitute a breach of any of the terms or provisions of, or a default under, (i) the Third Amendment and Restatement of Declaration of Trust, as amended and supplemented (the “Declaration of Trust”), or the Amended and Restated By-laws, as amended, of the Company or the charter or by-laws or other organizational documents of any subsidiary of the Company, (ii) any agreement, indenture or other instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries or their respective properties or assets is bound, or (iii) any laws, administrative regulations or rulings or decrees to which the Company or any of its subsidiaries or their respective properties or assets may be subject.

(xvii) No consent, approval, authorization or order of, or registration, filing or qualification with, any governmental body or regulatory agency having jurisdiction over the Company or any of its subsidiaries or any of their respective properties or assets is required for the execution, delivery and performance of this Agreement and the consummation of the transactions contemplated hereby, including, without limitation, the issuance, sale and delivery of the Preferred Shares pursuant to this Agreement, and the issuance of the Common Shares upon conversion of the Preferred Shares, except for the filing of the Articles Supplementary or such as have been obtained or made and such as may be required under foreign and state securities or “Blue Sky” or real estate syndication laws, it being understood that the Articles Supplementary have not been filed with the State Department of Assessments and Taxation of the State of Maryland (“SDAT”) as of the date hereof, but that such document will be filed with the SDAT prior to the Closing Time.

(xviii) Except as otherwise disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, the Company and each of its subsidiaries has good and marketable fee or leasehold title to all real properties described in the Registration Statement, the General Disclosure Package or the Prospectus as being owned or leased by it, free and clear of all liens, claims, encumbrances and restrictions, except liens for taxes not yet due and payable and other liens, claims, encumbrances and restrictions which do not, either individually or in the aggregate, materially and adversely affect the current use or value of the real properties of the Company and its subsidiaries,

taken as a whole. Except as otherwise set forth in the Registration Statement, the General Disclosure Package and the Prospectus, all leases to which the Company and each of its subsidiaries is a party which are material to the business of the Company and its subsidiaries, taken as a whole, are valid and binding on the Company or such subsidiaries and, to the Company’s knowledge, each applicable tenant. Except as otherwise set forth in the Registration Statement, the General Disclosure Package and the Prospectus, no default under any such lease by the Company or any subsidiary of the Company or, to the Company’s knowledge, any tenant has occurred and is continuing which default would, individually or in the aggregate, have a Material Adverse Effect. With respect to all properties owned or leased by the Company and each of its subsidiaries, the Company or such subsidiary has such documents, instruments, certificates, opinions and assurances, including without limitation, fee, leasehold owners or lender’s title insurance policies (disclosing no encumbrances or title exceptions which are material to the Company and its subsidiaries considered as a whole, except as otherwise set forth in the Registration Statement, the General Disclosure Package and the Prospectus), legal opinions and title insurance policies in each case in form and substance as are usual and customary in transactions involving the purchase of similar real estate and are appropriate for the Company or such subsidiary to have obtained, except where failure to obtain the same would not, individually, or in the aggregate, have a Material Adverse Effect.

(xix) The Company and each of its subsidiaries owns, or possesses adequate rights to use, all patents, trademarks, trade names, service marks, copyrights, licenses and other rights necessary for the conduct of their respective businesses as described in the Registration Statement, the General Disclosure Package and the Prospectus, and neither the Company nor any of its subsidiaries has received any notice of conflict with, or infringement of, the asserted rights of others with respect to any such patents, trademarks, trade names, service marks, copyrights, licenses and other such rights (other than conflicts or infringements that, if proven, would not have a Material Adverse Effect, and neither the Company nor any of its subsidiaries knows of any basis therefor.

(xx) All material tax returns required to be filed by the Company and each of its subsidiaries in any jurisdiction have been timely filed, other than those filings being contested in good faith, and all material taxes, including withholding taxes, penalties and interest, assessments, fees and other charges due pursuant to such returns or pursuant to any assessment received by the Company or any of its subsidiaries have been paid, other than those being contested in good faith and for which adequate reserves have been provided.

(xxi) Except as otherwise set forth in the Registration Statement, the General Disclosure Package and the Prospectus, to the Company’s knowledge, after due investigation (i) the Company and its subsidiaries have been and are in compliance in all material respects with, and neither the Company nor its subsidiaries have any liability under, applicable Environmental Laws (as hereinafter defined) except for such non-compliance or liability which is not material to the Company and its subsidiaries, taken as a whole; (ii) neither the Company nor its subsidiaries have at any time released (as such term is defined in Section 101 (22) of CERCLA (as hereinafter defined)) or otherwise disposed of or handled, Hazardous Materials (as hereinafter defined) on, to or from the real properties or other assets owned by the Company or its subsidiaries, except for such

releases, disposals and handlings as would not be reasonably likely to cause the Company or its subsidiaries to incur liability which is material to the Company and its subsidiaries, taken as a whole; (iii) neither the Company nor its subsidiaries intend to use the real properties or other assets owned by them other than in compliance in all material respects with applicable Environmental Laws, (iv) neither the Company nor any of its subsidiaries knows of any seepage, leak, discharge, release, emission, spill, or dumping of Hazardous Materials into waters (including, but not limited to, groundwater and surface water) on, beneath or adjacent to the real properties or other assets owned by them, other than such matters as would not be reasonably likely to cause the Company or its subsidiaries to incur liability which is material to the Company and its subsidiaries, taken as a whole; (v) neither the Company nor any of its subsidiaries has received any written notice of, or has any knowledge of any occurrence or circumstance which, with notice or passage of time or both, would be reasonably likely to give rise to a claim under or pursuant to any Environmental Law by any governmental or quasi-governmental body or any third party with respect to the real properties or the assets of the Company or its subsidiaries or arising out of their conduct, except for such claims that would not be reasonably likely to cause the Company or its subsidiaries to incur liability which is material to the Company and its subsidiaries, taken as a whole, and that would not be required to be disclosed in the Registration Statement, the General Disclosure Package or the Prospectus; (vi) none of the real properties owned by the Company or its subsidiaries is included or proposed for inclusion on the National Priorities List issued pursuant to CERCLA by the United States Environmental Protection Agency or on any similar list or inventory issued by any other federal, state or local governmental authority having or claiming jurisdiction over such properties pursuant to any other Environmental Law other than such inclusions or proposed inclusions as would not be reasonably likely to cause the Company or its subsidiaries to incur liability which is material to the Company and its subsidiaries taken as a whole. As used herein, “Hazardous Material” shall include, without limitation, any flammable explosives, radioactive materials, chemicals, hazardous wastes, toxic substances, petroleum or petroleum products, asbestos-containing materials, toxic mold or any hazardous material as defined by any federal, state or local law, ordinance, rule or regulation relating to the protection of human health (with respect to exposure to Hazardous Materials), the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata) or wildlife, including, without limitation, the Comprehensive Environmental Response, Compensation and Liability Act of 1980, as amended, 42 U.S.C. Secs. 9601-9675 (“CERCLA”), the Hazardous Materials Transportation Act, as amended, 49 U.S.C. Secs. 5101-5127, the Solid Waste Disposal Act, as amended, 42 U.S.C. Secs. 6901-6992k, the Emergency Planning and Community Right-to-Know Act of 1986, 42 U.S.C. Secs. 11001-11050, the Toxic Substances Control Act, 15 U.S.C. Secs. 2601-2692, the Federal Insecticide, Fungicide and Rodenticide Act, 7 U.S.C. Secs. 136-136y, the Clean Air Act, 42 U.S.C. Secs. 7401-7671q, the Clean Water Act (Federal Water Pollution Control Act), 33 U.S.C. Secs. 1251-1387, and the Safe Drinking Water Act, 42 U.S.C. Secs. 300f-300j-26, as any of the above statutes may be amended from time to time, and the regulations promulgated pursuant to any of the foregoing (individually, an “Environmental Law” and collectively “Environmental Laws”).

(xxii) Each of the Company and its subsidiaries has such permits, licenses, franchises and authorizations of governmental or regulatory authorities (together,

“permits”), including, without limitation, under any applicable Environmental Law, as are necessary to own, lease and operate its properties and to engage in the business currently conducted by it, except such permits as to which the failure to own or possess will not in the aggregate have a Material Adverse Effect. All such permits are in full force and effect and each of the Company and its subsidiaries is in compliance with the terms and conditions of all such permits, except where the invalidity of such permits or the failure of such permits to be in full force and effect or the failure to comply with such permits will not in the aggregate have a Material Adverse Effect. Neither the Company nor any of its subsidiaries has received any notice of proceedings relating to the revocation or modification of any permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have a Material Adverse Effect.

(xxiii) To the knowledge of the Company, no labor problem exists or is imminent with employees of the Company or any of its subsidiaries that could have a Material Adverse Effect.

(xxiv) Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company, any officer, trustee or director purporting to act on behalf of the Company or any of its subsidiaries, has at any time: (i) made any contributions to any candidate for political office, or failed to disclose fully any such contributions, in violation of law; (ii) made any payment of funds to, or received or retained any funds from, any state, federal or foreign governmental officer or official, or other person charged with similar public or quasi-public duties, other than payments required or allowed by applicable law; or (iii) engaged in any transactions, maintained any bank accounts or used any corporate funds, except for transactions, bank accounts and funds, which have been and are reflected in the normally maintained books and records of the Company and its subsidiaries.

(xxv) All of the outstanding shares of beneficial interest of, or other ownership interests in, each of the Company’s subsidiaries have been duly authorized and validly issued and are fully paid and, except as to subsidiaries that are partnerships, non-assessable, and, except as disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, are or will be owned by the Company free and clear of any security interest, claim, lien, encumbrance or adverse interest of any nature.

(xxvi) Except as referred to or described in the Registration Statement, the General Disclosure Package and the Prospectus, none of the subsidiaries of the Company owns any shares of stock or any other securities of any corporation or has any equity interest in any firm, partnership, association or other entity other than the issued capital shares of or interests in its subsidiaries, and the Company does not own, directly or indirectly, any shares of stock or any other securities of any corporation or have any equity interest in any firm, partnership, association or other entity other than the issued capital shares of or interests in its subsidiaries, except in each case for non-controlling positions acquired in the ordinary course of business.

(xxvii) Except as disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, there are no material outstanding loans or advances or material guarantees of indebtedness by the Company or any of its subsidiaries to or for

the benefit of any of the officers, trustees or directors of the Company or any of its subsidiaries or any of the members of the families of any of them.

(xxviii) The Company and each of its subsidiaries maintains insurance, duly in force, with insurers of recognized financial responsibility; such insurance insures against such losses and risks as are adequate in accordance with customary industry practice to protect the Company and its subsidiaries and their respective businesses; and neither the Company nor any such subsidiary has any reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not materially and adversely affect the business, operations, earnings, prospects, properties or condition (financial or otherwise) of the Company and its subsidiaries, taken as a whole, except as disclosed in or contemplated by the Registration Statement, the General Disclosure Package and the Prospectus.

(xxix) Neither the Company nor any of its officers and directors (as defined in the 1933 Act Regulations) has taken or will take, directly or indirectly, prior to the termination of the offering contemplated by this Agreement, any action designed to stabilize or manipulate the price of any security of the Company, or which has caused or resulted in, or which might in the future reasonably be expected to cause or result in, stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Preferred Shares.

(xxx) Neither the Company nor any of its subsidiaries is, and upon the issuance and sale of the Preferred Shares as herein contemplated and the application of the net proceeds therefrom or upon the issuance of the Common Shares issuable upon conversion of the Preferred Shares as described in each of the Registration Statement, the General Disclosure Package and the Prospectus, will be, an “investment company” or an “affiliated person” of, or “promoter” or “principal underwriter” for, an “investment company” as such terms are defined in the Investment Company Act of 1940, as amended (the “1940 Act”), or an “investment adviser” as such term is defined in the Investment Advisers Act of 1940, as amended.

(xxxi) The Company is organized in conformity with the requirements for qualification, and, as of the date hereof the Company operates, and as of Closing Time (and, if any Option Shares are purchased, at the Date of Delivery), the Company will operate, in a manner that qualifies the Company as a “real estate investment trust” under the Internal Revenue Code of 1986, as amended (the “Code”), and the rules and regulations thereunder, for 2011 and subsequent years. The Company qualified as a real estate investment trust under the Code for each of its taxable years from 1987 through 2010.

(xxxii) No default exists, and no event has occurred which, with notice or lapse of time or both, would constitute a default in the due performance and observance of any term, covenant or condition of any indenture, mortgage, deed of trust, lease or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries or any of their respective properties is bound or may be affected, except such defaults which, singly or in the aggregate, would

not have a Material Adverse Effect, except as disclosed in the Registration Statement, the General Disclosure Package and the Prospectus.

(xxxiii) The Company has established and maintains disclosure controls and procedures (as such term is defined in Rule 13a-15 and 15d-15 under the 1934 Act) that (a) are designed to ensure that material information relating to the Company, including its consolidated subsidiaries, is made known to the Company’s principal executive officer and its principal financial officer (or persons performing similar functions), particularly during the periods in which the filings made by the Company with the Commission which it may make under Sections 13(a), 13(c), 14 or 15(d) of the 1934 Act are being prepared, (b) have been evaluated for effectiveness as of the end of the period covered by the Company’s most recent Annual Report on Form 10-K filed with the Commission and (c) are effective to perform the functions for which they were established. The principal executive officers (or their equivalents) and principal financial officers (or their equivalents) of the Company have made all certifications required by Sections 302 and 906 of the Sarbanes-Oxley Act of 2002 and any related rules and regulations promulgated by the Commission, and the statements contained in any such certification were correct when made. The Company’s independent registered public accounting firm and the audit committee of the board of trustees of the Company have been advised of (x) any significant deficiencies in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the Company’s ability to record, process, summarize, and report financial data and (y) any fraud, whether or not material, that involves management or other employees who have a role in the Company’s internal control over financial reporting. Neither the audit committee of the board of trustees of the Company or, to the Company’s knowledge, after due inquiry, the Company’s independent registered public accounting firm have been advised of the occurrence of any of the matters identified in clause (x) or (y) of the immediately preceding sentence. Since the date of the most recent evaluation of such disclosure controls and procedures, there have been no significant changes in the Company’s internal control over financial reporting or in other factors that have materially affected or are reasonably likely to materially affect the Company’s internal control over financial reporting.

(xxxiv) Except as otherwise disclosed in the General Disclosure Package, subsequent to the respective dates as of which information is given in the General Disclosure Package, there has been no material adverse change in the business, operations, earnings, prospects, properties or condition (financial or otherwise) of the Manager, whether or not arising in the ordinary course of business, that would have a material adverse effect on the Company and its subsidiaries, taken as a whole. The Business Management Agreement, dated as of June 8, 2009, as amended (the “Advisory Agreement”), between the Company and the Manager, has been duly authorized, executed and delivered by the parties thereto and constitutes the valid agreement of the parties thereto, enforceable in accordance with its terms, except as limited by (a) the effect of bankruptcy, insolvency, reorganization, moratorium, fraudulent transfer or other similar laws relating to or affecting the rights or remedies of creditors or (b) the effect of general principles of equity (regardless of whether enforcement is sought in a proceeding in equity or at law).

(xxxv) Neither the Company nor, to the knowledge of the Company, any trustee, officer, agent, affiliate or other person acting on behalf of the Company or its subsidiaries has taken any action, directly or indirectly, that would result in a violation by such persons of the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (the “FCPA”), including, without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA and the Company and, to the knowledge of the Company, its affiliates have conducted their businesses in compliance with the FCPA and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith.

(xxxvi) The operations of the Company are and have been conducted at all times in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all jurisdictions, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company with respect to the Money Laundering Laws is pending or, to the knowledge of the Company, threatened.

(xxxvii) Neither the Company nor, to the knowledge of the Company, any trustee, officer, agent, affiliate or person acting on behalf of the Company is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”); and the Company will not directly or indirectly use the proceeds of the offering, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other person or entity, for the purpose of financing the activities of any person currently subject to any U.S. sanctions administered by OFAC.

Any certificate signed by any officer of the Company or any of its subsidiaries and delivered to the Representatives or to counsel for the Underwriters shall be deemed a representation and warranty by the Company to each Underwriter as to the matters covered thereby.

Section 2. Sale and Delivery to the Underwriters; Closing .

(a) On the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company agrees to sell to each Underwriter, severally and not jointly, and each Underwriter, severally and not jointly, agrees to purchase from the Company, at a price per share of $24.2125, the number of Initial Shares set forth in Schedule A opposite the name of such Underwriter, plus any additional number of Initial Shares which such Underwriter may become obligated to purchase pursuant to the provisions of Section 10 hereof.

(b) In addition, on the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company hereby grants an option to the Underwriters, severally and not jointly, to purchase up to an additional 1,500,000 Preferred Shares at the price per share set forth above. The option hereby granted will expire 30 days after the date hereof and may be exercised in whole or in part from time to time only for the purpose of covering overallotments which may be made in connection with the offering and distribution of the Initial Shares upon notice by the Representatives to the Company setting forth the number of Option Shares as to which the several Underwriters are then exercising the option and the time and date of payment and delivery for such Option Shares. Such time and date of delivery (a “Date of Delivery”) shall be determined by the Representatives, but shall not be later than seven full business days after the exercise of said option, nor in any event prior to the Closing Time, as hereinafter defined. If the option is exercised as to all or any portion of the Option Shares, each of the Underwriters, acting severally and not jointly, will purchase that proportion of the total number of Option Shares then being purchased which the number of Initial Shares set forth in Schedule A opposite the name of such Underwriter bears to the total number of Initial Shares, subject in each case to such adjustments as the Representatives in their discretion shall make to eliminate any sales or purchases of fractional shares.

(c) Payment of the purchase price for and delivery of the Initial Shares shall be made, subject to Section 9, at the offices of Sullivan & Worcester LLP, One Post Office Square, Boston, Massachusetts 02109, or at such other place as shall be agreed upon by the Representatives and the Company, at 9:00 A.M. on the third business day (unless postponed in accordance with the provisions of Section 10 hereof) following the date of this Agreement, or such other time not later than ten business days after such date as shall be agreed upon by the Representatives and the Company (such time and date of payment and delivery being herein called “Closing Time”).

In addition, in the event that any or all of the Option Shares are purchased by the Underwriters, payment of the purchase price for, and delivery of, such Option Shares shall be made at the above-mentioned offices, or at such other place as shall be agreed upon by the Representatives and the Company, on each Date of Delivery as specified in the notice from the Representatives to the Company.

Payment shall be made by wire transfer of immediately available funds to an account designated by the Company against delivery to the Representatives for the respective accounts of the Underwriters of certificates for, or other evidence of, the Shares to be purchased by them. It is understood that each Underwriter has authorized the Representatives, for its account, to accept delivery of and receipt for, and to make payment of the purchase price for the Initial Shares, and the Option Shares, if any, which it has agreed to purchase. The Representatives, individually and not as representatives of the several Underwriters may (but shall not be obligated to) make payment of the purchase price for the Initial Shares, and the Option Shares, if any, to be purchased by any Underwriter whose funds have not been received by Closing Time, or the relevant Date of Delivery, as the case may be, but any such payment shall not relieve such Underwriter from its obligations hereunder.

(d) The certificates for, or other evidence of, the Initial Shares and the Option Shares, if any, shall be in such denominations and registered in such names as the Representatives may request in writing at least one full business day before the Closing Time or the relevant Date of

Delivery, as the case may be. The certificates for, or other evidence of, the Initial Shares and the Option Shares, if any, will be made available for examination by the Representatives not later than 10:00 A.M. (Eastern time) on the business day prior to Closing Time or the relevant Date of Delivery, as the case may be.

Section 3. Covenants of the Company . The Company covenants with each Underwriter as follows:

(a) Immediately following the execution of this Agreement, the Company will prepare the Prospectus setting forth the number of Preferred Shares covered thereby and their terms not otherwise specified in the preliminary prospectus, the Underwriters’ names, the price at which the Preferred Shares are to be purchased by the Underwriters from the Company, and such other information as the Representatives and the Company deem appropriate in connection with the offering of the Preferred Shares; the Company will effect the filings required under Rule 424(b), in the manner and within the time period required by Rule 424(b) (without reliance on Rule 424(b)(8)), and will furnish to the Underwriters as many copies of the Prospectus as they shall reasonably request including, if requested by the Underwriters, in addition to or in lieu thereof, electronic copies of the Prospectus. The Company shall pay the required Commission filing fees relating to the Preferred Shares within the time required by Rule 456(b)(1) (i) of the 1933 Act Regulations and otherwise in accordance with Rules 456(b) and 457(r) of the 1933 Act Regulations.

(b) During the period beginning on the Applicable Time and ending on the later of the Closing Time or such date, as in the reasonable opinion of counsel for the Underwriters, the Prospectus is no longer required under the 1933 Act or the 1934 Act to be delivered in connection with sales by the Underwriters or a dealer, including in circumstances where such requirement may be satisfied pursuant to Rule 172 (the “Prospectus Delivery Period”), the Company will comply with the requirements of Rule 430B and will notify the Representatives immediately, and confirm the notice in writing, (i) of the transmittal to the Commission for filing of any amendment to the Registration Statement, (ii) of the transmittal to the Commission for filing of any supplement or amendment to the Prospectus or any document to be filed pursuant to the 1934 Act, (iii) of the receipt of any comments from the Commission with respect to the Registration Statement or the Prospectus or documents incorporated or deemed to be incorporated by reference therein, (iv) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus with respect to the Preferred Shares or for additional information relating thereto, and (v) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or the initiation of any proceedings for that purpose. The Company will make every reasonable effort to prevent the issuance of any such stop order and, if any stop order is issued, to obtain the lifting thereof at the earliest possible moment.

(c) During the Prospectus Delivery Period, prior to amending or supplementing the Registration Statement (including any filing under Rule 462(b)), any preliminary prospectus or the Prospectus (including any amendment or supplement through incorporation by reference of any report filed under the 1934 Act), the Company will furnish to the Representatives for review a copy of each such proposed amendment or supplement a reasonable amount of time prior to such proposed filing or use, as the case may be, and will not file any such amendment or supplement or use any such prospectus to which counsel for the Underwriters shall reasonably

object. The Company has given the Representatives notice of any filings made pursuant to the 1934 Act or 1934 Act Regulations within 48 hours prior to the Applicable Time; the Company will give the Representatives notice of its intention to make any such filing from the Applicable Time to the Closing Time and will furnish the Representatives with copies of any such documents a reasonable amount of time prior to such proposed filing and will not file or use any such document to which the Representatives or counsel for the Underwriters shall reasonably object. The Company will prepare a final term sheet substantially in the form as attached to Schedule B hereto (the “Final Term Sheet”) reflecting the final terms of the Preferred Shares, and shall file such Final Term Sheet as an “issuer free writing prospectus” pursuant to Rule 433 prior to the close of business two business days after the date hereof; provided that the Company shall furnish the Representatives with copies of any such Final Term Sheet a reasonable amount of time prior to such proposed filing and will not use or file any such document to which the Representatives or counsel for the Underwriters shall reasonably object.

(d) Upon request, the Company will deliver to the Representatives a conformed copy of the Original Registration Statement as originally filed and of each amendment thereto filed prior to the termination of the initial offering of the Preferred Shares (including exhibits filed therewith or incorporated by reference therein and the documents incorporated by reference into the Prospectus pursuant to Item 12 of Form S-3).

(e) The Company will furnish to the Representatives, from time to time during the period when the Prospectus is required to be delivered under the 1933 Act or the 1934 Act in connection with the offering, such number of copies of the Prospectus (as amended or supplemented) as the Underwriters may reasonably request for the purposes contemplated by the 1933 Act, the 1933 Act Regulations, the 1934 Act or 1934 Act Regulations including, if requested by the Underwriters, in addition to or in lieu thereof, electronic copies of the Prospectus.

(f) If at any time when a prospectus is required by the 1933 Act to be delivered in connection with the sale of the Preferred Shares, any event shall occur as a result of which it is necessary, in the opinion of counsel for the Underwriters, which shall be communicated by the Underwriters through the Representatives in writing to the Company, to amend or supplement the Prospectus in order to make the Prospectus not misleading in the light of the circumstances existing at the time it is delivered, the Company will either (i) forthwith prepare and furnish to the Representatives an amendment of or supplement to the Prospectus or (ii) make an appropriate filing pursuant to Section 13, 14 or 15 of the 1934 Act, in form and substance reasonably satisfactory to counsel for the Underwriters, which will amend or supplement the Prospectus so that it will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at the time it is delivered, not misleading. If at any time after the date hereof, an event or development occurs as a result of which the General Disclosure Package contains an untrue statement of a material fact or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at the time it is used, not misleading, the Company will promptly notify the Representatives and will promptly amend or supplement in a manner reasonably satisfactory to the Representatives, at its own expense, the General Disclosure Package to eliminate or correct such untrue statement or omission. If at any time following issuance of an Issuer Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the

information contained in the Registration Statement (or any other registration statement relating to the Preferred Shares) or the Statutory Prospectus or any preliminary prospectus or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at that subsequent time, not misleading, the Company will promptly notify the Representatives and will promptly amend or supplement, at its own expense, such Issuer Free Writing Prospectus to eliminate or correct such conflict, untrue statement or omission.

(g) The Company represents and agrees that, unless it obtains the prior written consent of the Representatives, and each Underwriter agrees that, unless it obtains the prior written consent of the Company and the Representatives, it has not made and will not make any offer relating to the Preferred Shares or the Common Shares that would constitute an “issuer free writing prospectus”, as defined in Rule 433, or that would otherwise constitute a “free writing prospectus,” as defined in Rule 405, required to be filed with the Commission; provided, however, that prior to the preparation of the Final Term Sheet in accordance with Section 3(c), the Underwriters are authorized to use the information with respect to the final terms of the Preferred Shares in communications conveying information relating to the offering to investors. Any such free writing prospectus consented to by the Company and the Representatives is hereinafter referred to as a “Permitted Free Writing Prospectus.” The Company represents that it has treated or agrees that it will treat each Permitted Free Writing Prospectus as an “issuer free writing prospectus,” as defined in Rule 433, and has complied and will comply with the requirements of Rule 433 applicable to any Permitted Free Writing Prospectus, including timely filing with the Commission where required, legending and record keeping.

(h) The Company will endeavor in good faith, in cooperation with the Representatives, to qualify the Preferred Shares and the Common Shares issuable upon conversion for offering and sale under the applicable securities laws and real estate syndication laws of such states and other jurisdictions of the United States as the Representatives may designate; provided that, in connection therewith, the Company shall not be required to qualify as a foreign corporation or trust or to file any general consent to service of process. In each jurisdiction in which the Preferred Shares have been so qualified the Company will file such statements and reports as may be required by the laws of such jurisdiction to continue such qualification in effect for so long as required for the distribution of the Preferred Shares.

(i) The Company will make generally available to its security holders as soon as reasonably practicable, but not later than 90 days after the close of the period covered thereby, an earning statement of the Company (in form complying with the provisions of Rule 158 of the 1933 Act Regulations) covering a period of at least twelve months beginning not later than the first day of the Company’s fiscal quarter next following the effective date of the Registration Statement. “Earning statement”, “make generally available” and “effective date” will have the meanings contained in Rule 158 of the 1933 Act Regulations.

(j) The Company will use the net proceeds received by it from the sale of the Preferred Shares in the manner specified in the General Disclosure Package and the Prospectus under the caption “Use of Proceeds” in all material respects.

(k) The Company will use its best efforts to effect the listing of the Preferred Shares on the NYSE.

(l) The Company currently intends to continue to qualify as a “real estate investment trust” under the Code, and use its best efforts to continue to meet the requirements for qualification as a “real estate investment trust” under the Code.

(m) The Company will timely file any document which it is required to file pursuant to the 1934 Act prior to the termination of the offering of the Preferred Shares.

(n) During a period of 30 days from the date of the Prospectus, the Company will not, without the prior written consent of the Representatives, directly or indirectly (i) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of, or lend or otherwise transfer or dispose of any Series E Shares or any securities convertible into or exercisable or exchangeable for or repayable with Series E Shares, whether owned as of the date hereof or hereafter acquired or with respect to which such person has or hereafter acquires the power of disposition, or file, or cause to be filed, any registration statement under the 1933 Act with respect to any of the foregoing (collectively, the “Lock-Up Securities”) or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Lock-Up Securities, whether any such swap, agreement or transaction is to be settled by delivery of Series E Shares or other securities, in cash or otherwise. The foregoing sentence shall not apply to (i) the Series E Shares which are to be sold pursuant to this Agreement, (ii) Series E Shares issued or to be issued pursuant to the Company’s Incentive Share Award Plan, (iii) Series E Shares to be issued to the Manager in payment of its incentive fee and (iv) Series E Shares to be issued as partial or full payment for properties directly or indirectly acquired or to be acquired by the Company or its subsidiaries; provided that, the Company shall have conditioned the issuance of such Series E Shares upon the agreement of the recipients to the restrictions of this paragraph (n).

(o) The Company will use its best efforts to file, prior to the Closing Time, with the SDAT the Articles Supplementary.

(p) The Company will reserve and keep available at all times, free of any preemptive rights, the maximum number of Common Shares issuable upon conversion of the Preferred Shares until such time as such Common Shares have been issued or the Preferred Shares have been redeemed.

Section 4. Payment of Expenses . The Company will pay all expenses incident to the performance of its obligations under this Agreement, including (i) the preparation and filing of the Registration Statement as originally filed and of each amendment thereto, (ii) the preparation and filing of this Agreement, (iii) the preparation, issuance and delivery of the Preferred Shares to the Underwriters, (iv) the fees and disbursements of counsel for the Company, referred to in Section 5(b) hereof, and the Company’s accountants, (v) the qualification of the Preferred Shares and the Common Shares issuable upon conversion under securities laws and real estate syndication laws in accordance with the provisions of Section 3(h) hereof, including filing fees and the fee and disbursements of counsel for the Company or the Underwriters in connection therewith and in connection with the preparation of any Blue Sky Survey, (vi) the printing and delivery to the Underwriters of copies of the Registration Statement, each preliminary prospectus, any Permitted Free Writing Prospectus and the Prospectus and any amendments or supplements thereto, and of the Prospectus and any amendments or supplements thereto, (vii) the

fees and expenses incurred in connection with the listing of the Preferred Shares on the NYSE, (viii) the cost of printing or reproducing and delivering to the Underwriters copies of any Blue Sky Survey, (ix) the cost of providing any CUSIP or other identification numbers for the Preferred Shares, (x) any applicable Financial Industry Regulatory Authority (“FINRA”) filing fees, (xi) the costs and expenses (including without limitation any damages or other amounts payable in connection with legal or contractual liability) associated with the reforming of any contracts for sale of the Preferred Shares made by the Underwriters caused by a breach of the representation contained in the sixth paragraph of Section 1(a)(ii) and (xii) any transfer taxes imposed on the sale of the Preferred Shares to the Underwriters.

If this Agreement is terminated by the Representatives in accordance with the provisions of Section 5 or Section 9(a)(i), the Company shall reimburse the Underwriters for all of their out-of-pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriters.

Section 5. Conditions of the Underwriters’ Obligations . The obligations of the Underwriters hereunder are subject to the accuracy of the representations and warranties of the Company herein contained, to the performance by the Company of its obligations hereunder, and to the following further conditions:

(a) At Closing Time no stop order suspending the effectiveness of the Registration Statement shall have been issued under the 1933 Act or proceedings therefor initiated or threatened by the Commission. A prospectus containing the Rule 430B Information shall have been filed with the Commission in the manner and within the time period required by Rule 424(b) without reliance on Rule 424(b)(8) (or a post-effective amendment providing such information shall have been filed and become effective in accordance with the requirements of Rule 430B) and any required filing of each Issuer Free Writing Prospectus pursuant to Rule 433 has been made in the manner and within the time period required by Rule 433(d).

(b) At Closing Time the Representatives shall have received the favorable opinion, dated as of Closing Time, of Sullivan & Worcester LLP, counsel for the Company, in form and substance reasonably satisfactory to counsel for the Underwriters, together with signed or reproduced copies of such letter for each of the other Underwriters.

In rendering their opinion, Sullivan & Worcester LLP may rely upon an opinion, dated as of Closing Time, of Venable LLP as to matters governed by Maryland law, provided that such reliance is expressly authorized by such opinion. In addition, in rendering such opinion, such counsel may state that their opinion as to laws of the State of Delaware is limited to the Delaware General Corporation Law, the Delaware Revised Uniform Limited Partnership Act and the Delaware Limited Liability Company Act, that their opinions, if any, with respect to subsidiaries organized in jurisdictions other than Massachusetts or Delaware are based on their review of statutes of such jurisdictions comparable to such Delaware statutes, and that their opinion with respect to the qualification of the Company and its subsidiaries to do business in jurisdictions other than their respective jurisdictions of organization is based solely upon certificates to such effect issued by an appropriate official of the applicable jurisdictions.

(c) At Closing Time the Representatives shall have received the favorable opinion, dated as of Closing Time, of Venable LLP, special Maryland counsel for the Company, in form

and substance reasonably satisfactory to counsel for the Underwriters, together with signed or reproduced copies of such letter for each of the other Underwriters.

(d) The Representatives shall have received at Closing Time an opinion, dated as of Closing Time, of Sidley Austin LLP, counsel for the Underwriters, together with signed or reproduced copies of such letter for each of the other Underwriters, in form and substance reasonably satisfactory to the Representatives.

In rendering their opinion as aforesaid, Sidley Austin LLP may rely upon an opinion, dated as of Closing Time, of Venable LLP as to matters governed by Maryland law, and the opinion of Sullivan & Worcester LLP referred to above as to matters governed by Massachusetts law. In addition, in rendering such opinion, such counsel may state that its opinion as to laws of the State of Delaware is limited to the Delaware General Corporation Law.

(e) At Closing Time (i) the Registration Statement and the Prospectus shall contain all statements which are required to be stated therein in accordance with the 1933 Act and the 1933 Act Regulations and in all material respects shall conform to the requirements of the 1933 Act and the 1933 Act Regulations, and neither the Registration Statement nor the Prospectus shall contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, and no action, suit or proceeding at law or in equity shall be pending or to the knowledge of the Company threatened against the Company which would be required to be set forth in the Prospectus other than as set forth therein, (ii) there shall not have been, since the respective dates as of which information is given in the Registration Statement, the Prospectus, or the General Disclosure Package, any material adverse change in the condition, financial or otherwise, of the Company and its subsidiaries, taken as a whole, or in their earnings, business affairs or business prospects, whether or not arising in the ordinary course of business from that set forth in the Registration Statement, the Prospectus or the General Disclosure Package and (iii) no proceedings shall be pending or, to the knowledge of the Company, threatened against the Company before or by any federal, state or other commission, board or administrative agency wherein an unfavorable decision, ruling or finding would materially and adversely affect the business, property, financial condition or income of the Company other than as set forth in the General Disclosure Package and the Prospectus; and the Representatives shall have received, at Closing Time, a certificate of the President and Managing Trustee and the Treasurer and Chief Financial Officer of the Company, dated as of Closing Time, evidencing compliance with the provisions of this subsection (e) and stating that the representations and warranties set forth in Section 1(a) hereof are accurate as though expressly made at and as of Closing Time.

(f) At Closing Time, there shall not have been, since the respective dates as of which information is given in the Registration Statement and the Prospectus, or since the respective dates as of which information is given in the General Disclosure Package, any material adverse change in the business, operations, earnings, prospects, properties or condition (financial or otherwise) of the Manager, whether or not arising in the ordinary course of business; and the Representatives shall have received, at Closing Time, a certificate of the President or any Vice President of the Manager evidencing compliance with this subsection (f).

(g) Concurrently with the execution and delivery of this Agreement, and at Closing Time prior to payment and delivery of the Initial Shares, Ernst & Young LLP shall have

furnished to the Representatives a letter, dated the date of its delivery, addressed to the Underwriters and in form and substance satisfactory to the Representatives, confirming that they are an independent registered public accounting firm with respect to the Company as required by the 1933 Act and the 1933 Act Regulations and with respect to the financial and other statistical and numerical information contained in the Registration Statement and the Prospectus or incorporated by reference therein. Each such letter shall contain information of the type customarily included in accountants’ comfort letters to underwriters as of a specified date not more than three days prior to the date of such letter.

(h) At Closing Time counsel for the Underwriters shall have been furnished with such documents and opinions as they may reasonably require for the purpose of enabling them to pass upon the issuance and sale of the Preferred Shares as herein contemplated and related proceedings, or in order to evidence the accuracy of any of the representations or warranties, or the fulfillment of any of the conditions, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Preferred Shares as herein contemplated shall be reasonably satisfactory in form and substance to the Representatives and counsel for the Underwriters.

(i) In the event the Underwriters exercise their option provided in Section 2(b) hereof to purchase all or any portion of the Option Shares, the representations and warranties of the Company contained herein and the statements in any certificates furnished by the Company hereunder shall be true and correct as of the Date of Delivery and at the Date of Delivery the Underwriters shall have received:

(i) A certificate of the President and Managing Trustee and the Treasurer and Chief Financial Officer of the Company, dated such Date of Delivery, confirming that their certificate delivered at Closing Time pursuant to Section 5(e) hereof remains true and correct as of such Date of Delivery.

(ii) The favorable opinion of Sullivan & Worcester LLP, counsel for the Company, in form and substance reasonably satisfactory to counsel for the Underwriters, dated such Date of Delivery, relating to the Option Shares to be purchased on such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(b) hereof.

(iii) The favorable opinion of Venable LLP, special Maryland counsel for the Company, in form and substance reasonably satisfactory to counsel for the Underwriters, dated such Date of Delivery, relating to the Option Shares to be purchased on such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(c) hereof.

(iv) The favorable opinion of Sidley Austin LLP, counsel for the Underwriters, dated such Date of Delivery, relating to the Option Shares to be purchased on such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(d) hereof.

(v) A certificate of the President of the Manager confirming that his certificate delivered at Closing Time pursuant to Section 5(f) hereof remains true as of such Date of Delivery.

(vi) A letter from Ernst & Young LLP, in form and substance satisfactory to the Representatives, dated such Date of Delivery, substantially the same in scope and substance as the letter furnished to the Underwriters pursuant to Section 5(g) hereof, except that the “specified date” in each letter furnished pursuant to this paragraph shall be a date not more than three days prior to such Date of Delivery.

(j) Subsequent to the execution and delivery of this Agreement and prior to Closing Time, or prior to the Date of Delivery in the case of the purchase of Option Shares on a Date of Delivery that is after the Closing Time, there shall not have occurred any downgrading, nor shall any notice have been given of (i) any intended or potential downgrading or (ii) any review or possible change that indicates anything other than a stable outlook, in the rating accorded any securities of or guaranteed by the Company by any nationally recognized statistical rating organization, as defined in Section 3(a)(62) of the Exchange Act; and the Preferred Shares shall be rated .

If any condition specified in this Section 5 shall not have been fulfilled when and as required to be fulfilled, this Agreement, or in the case of any condition to the purchase of Option Shares on a Date of Delivery that is after the Closing Time, the obligations of the Underwriters to purchase the relevant Option Shares, may be terminated by the Representatives by notice to the Company at any time at or prior to Closing Time, or such Date of Delivery, as the case may be, and such termination shall be without liability of any party to any other party except as provided in Section 4 hereof.

Section 6. Indemnification . (a) The Company hereby agrees to indemnify and hold harmless each Underwriter, their respective officers, directors and agents, their affiliates, and each person, if any, who controls each Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act as follows:

(1) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, arising out of any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or any amendment thereto), including the Rule 430B Information, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading or arising out of any untrue statement or alleged untrue statement of a material fact included in any preliminary prospectus, the General Disclosure Package or the Prospectus (or any amendment or supplement thereto), or the omission, or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

(2) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, to the extent of the aggregate amount paid in settlement of any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or of any claim whatsoever based upon any

such untrue statement or omission, or any such alleged untrue statement or omission, if such settlement is effected with the written consent of the Company; and

(3) against any and all expense whatsoever, as incurred (including, subject to Section 6(c) hereof, the fees and disbursements of counsel chosen by the Representatives), reasonably incurred in investigating, preparing or defending against any litigation, or any investigation or proceedings by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, or any such failure, to the extent that any such expense is not paid under paragraph (1) or (2) above;

provided, however, that this indemnity agreement shall not apply to any loss, liability, claim, damage or expense to the extent arising out of any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives expressly for use in the Registration Statement (or any amendment thereto), including the Rule 430B Information or any preliminary prospectus, the General Disclosure Package or the Prospectus (or any amendment or supplement thereto).

(b) Each Underwriter severally and not jointly agrees to indemnify and hold harmless the Company, the Company’s affiliates, each of the Company’s trustees, each of the Company’s officers who signed the Registration Statement and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act, against any and all loss, liability, claim, damage and expense described in the indemnity contained in subsection (a) of this Section 6, as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made in the Registration Statement (or any amendment thereto), including the Rule 430B Information, any preliminary prospectus, the General Disclosure Package or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with written information furnished to the Company by such Underwriter through the Representatives expressly for use therein.

(c) Each indemnified party shall give notice as promptly as reasonably practicable to each indemnifying party of any action commenced against it in respect of which indemnity may be sought hereunder, but failure to so notify an indemnifying party shall not relieve such indemnifying party from any liability which it may have otherwise than on account of this indemnity agreement. An indemnifying party may participate at its own expense in the defense of such action. In no event shall the indemnifying parties be liable for fees and expenses of more than one counsel (in addition to any local counsel) separate from their own counsel for all indemnified parties in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances.

Section 7. Contribution . In order to provide for just and equitable contribution in circumstances in which the indemnity agreement provided for in Section 6 hereof is for any reason held to be unenforceable by the indemnified parties although applicable in accordance with its terms, the Company and the Underwriters shall contribute to the aggregate losses, liabilities, claims, damages and expenses of the nature contemplated by said indemnity

agreement incurred by the Company and the Underwriters, as incurred, (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Preferred Shares pursuant to this Agreement or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company on the one hand and of the Underwriters on the other hand in connection with the statements or omissions which resulted in such losses, liabilities, claims, damages or expenses, as well as any other relevant equitable considerations.

The relative benefits received by the Company on the one hand and the Underwriters on the other hand in connection with the offering of the Preferred Shares pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the offering of the Preferred Shares pursuant to this Agreement (before deducting expenses) received by the Company and the total discount received by the Underwriters, bear to the aggregate initial offering price of the Preferred Shares.

The relative fault of the Company on the one hand and the Underwriters on the other hand shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 7 were determined by pro rata allocation or by any other method of allocation which does not take into account the equitable considerations referred to above in this Section 7. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and referred to above in this Section 7 shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission.

No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the 1933 Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. Notwithstanding the provisions of this Section 7, the Underwriters shall not be required to contribute any amount in excess of the amount by which the total price at which the Preferred Shares purchased from the Company by the Underwriters and distributed to the public were offered to the public exceeds the amount of any damages which the Underwriters have otherwise been required to pay in respect of such losses, liabilities, claims, damages and expenses. For purposes of this Section 7, each person, if any, who controls any Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act and shall have the same rights to contribution as such Underwriter, and each trustee of the Company, each officer of the Company who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act shall have the same rights to contribution as the Company. The Underwriters’ contribution obligations under this Section 7 are several, in proportion to their respective underwriting commitments, and not joint.

Section 8. Representations, Warranties and Agreements to Survive Delivery . All representations, warranties and agreements contained in this Agreement or in certificates of officers of the Company submitted pursuant hereto, shall remain operative and in full force and effect, regardless of any investigation made by or on behalf of the Underwriters or any controlling person, or by or on behalf of the Company, and shall survive delivery of the Preferred Shares to the Underwriters.

Section 9. Termination of Agreement . (a) The Representatives may terminate this Agreement, by notice to the Company, at any time at or prior to Closing Time (i) if there has been, since the respective dates as of which information is given in the Prospectus (exclusive of any supplement thereto) or the General Disclosure Package, any material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or business prospects of the Company and its subsidiaries, taken as a whole, or the Manager, whether or not arising in the ordinary course of business, which would make it, in the Representatives’ judgment, impracticable or inadvisable to market the Preferred Shares or enforce contracts for the sale of the Preferred Shares, (ii) if there has occurred any material adverse change in the financial markets in the United States or any outbreak of hostilities or escalation of existing hostilities or other calamity or any change or development involving a prospective change in national or international political, financial or economic conditions, in each case the effect of which is such to make it, in the Representatives’ judgment, impracticable or inadvisable to market the Preferred Shares or enforce contracts for the sale of the Preferred Shares, or (iii) if trading in the Common Shares has been suspended by the Commission, or if trading generally on either the NYSE or the Nasdaq Stock Market has been suspended, or minimum or maximum prices for trading have been fixed, or maximum ranges for prices for securities have been required, by either of said exchanges or by order of the Commission or any other governmental authority, or a material disruption has occurred in commercial banking or securities settlement or clearance services in the United States, or (iv) if a banking moratorium has been declared by Federal or New York authorities.

(b) If this Agreement is terminated pursuant to this Section 9, such termination shall be without liability of any party to any other party except as provided in Section 4, and provided further that Sections 6 and 7 hereof shall survive such termination.

Section 10. Default . If one or more of the Underwriters shall fail at the Closing Time to purchase the Initial Shares which it or they are obligated to purchase under this Agreement (the “Defaulted Shares”), the Representatives shall have the right, within 24 hours thereafter, to make arrangements for one or more of the non-defaulting Underwriters, or any other underwriters, to purchase all, but not less than all, of the Defaulted Shares in such amounts as may be agreed upon and upon the terms herein set forth; if, however, the Representatives shall not have completed such arrangements within such 24-hour period, then:

(i) if the number of Defaulted Shares does not exceed 10% of the Initial Shares, the non-defaulting Underwriters shall be obligated to purchase the full amount thereof in the proportions that their respective underwriting obligations hereunder bear to the underwriting obligations of all non-defaulting Underwriters, or

(ii) if the number of Defaulted Shares exceeds 10% of the Initial Shares, this Agreement shall terminate without liability on the part of any non-defaulting Underwriter and the Company.

No action taken pursuant to this Section 10 shall relieve any defaulting Underwriter from liability in respect of its default.

In the event of any such default which does not result in a termination of this Agreement, either the Representatives or the Company shall have the right to postpone Closing Time for a period not exceeding seven days in order to effect any required changes in the Prospectus or in any other documents or arrangements.

Section 11. Notices . All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted by any standard form of telecommunication. Notices to the Underwriters shall be directed to the Representatives c/o Merrill Lynch, Pierce, Fenner & Smith Incorporated, One Bryant Park, NY1-100-18-03, New York, NY 10036, Attention: High Grade Transaction Management/Legal (fax no.: 646-855-5958), c/o Citigroup Global Markets Inc., 388 / 390 Greenwich Street, New York, NY 10013, Attention: General Counsel (fax no.: 212-816-7912), UBS Securities LLC at 677 Washington Boulevard, Stamford, CT 06901, Attention: Fixed Income Syndicate (fax: (203) 719-0495) and c/o Wells Fargo Securities, LLC 301 S. College Street, Charlotte, NC 28288, Attention: Transaction Management (fax no.: 704-383-9165); and notices to the Company shall be directed to it at 400 Centre Street, Newton, Massachusetts 02458, Attention: John C. Popeo, Treasurer and Chief Financial Officer.

Section 12. No Fiduciary Relationship . The Company acknowledges and agrees that (i) the purchase and sale of the Preferred Shares pursuant to this Agreement, including the determination of the public offering price of the Preferred Shares and any related discounts and commissions, is an arm’s-length commercial transaction between the Company, on the one hand, and the several Underwriters, on the other hand, (ii) in connection with the offering contemplated hereby and the process leading to such transaction, each Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Company or its shareholders, creditors, employees or any other party, (iii) no Underwriter has assumed or will assume an advisory or fiduciary responsibility in favor of the Company with respect to the offering contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company on other matters) and no Underwriter has any obligation to the Company with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement, (iv) the Underwriters and their respective affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company, and (v) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company has consulted its own legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

Section 13. Parties . This Agreement shall inure to the benefit of and be binding upon the Underwriters and the Company and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, firm or corporation, other than those referred to in Sections 6 and 7 and their heirs and legal

representatives, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. This Agreement and all conditions and provisions hereof are intended to be for the sole and exclusive benefit of the parties hereto and their respective successors and said controlling persons and officers, trustees and directors and their heirs and legal representatives, and for the benefit of no other person, firm or corporation. No purchaser of Preferred Shares from any Underwriter shall be deemed to be a successor by reason merely of such purchase.

Section 14. Governing Law and Time; Miscellaneous . This Agreement shall be governed by and construed in accordance with the laws of the State of New York applicable to agreements made and to be performed in said State. Specified times of day refer to New York City time.

THE AMENDED AND RESTATED DECLARATION OF TRUST ESTABLISHING COMMONWEALTH REIT, DATED JULY 1, 1994, AS AMENDED AND SUPPLEMENTED, AS FILED WITH THE STATE DEPARTMENT OF ASSESSMENTS AND TAXATION OF MARYLAND, PROVIDES THAT NO TRUSTEE, OFFICER, SHAREHOLDER, EMPLOYEE OR AGENT OF COMMONWEALTH REIT SHALL BE HELD TO ANY PERSONAL LIABILITY, JOINTLY OR SEVERALLY, FOR ANY OBLIGATION OF, OR CLAIM AGAINST, COMMONWEALTH REIT. ALL PERSONS DEALING WITH COMMONWEALTH REIT, IN ANY WAY, SHALL LOOK ONLY TO THE ASSETS OF COMMONWEALTH REIT FOR THE PAYMENT OF ANY SUM OR THE PERFORMANCE OF ANY OBLIGATION.

If the foregoing is in accordance with your understanding of our agreement, please sign and return to us a counterpart hereof, whereupon this instrument along with all counterparts will become a binding agreement between the Underwriters and the Company in accordance with its terms.

Very truly yours,

COMMONWEALTH REIT

By	/s/ John C. Popeo
		Name:	John C. Popeo
		Title:	Treasurer and Chief Financial Officer

CONFIRMED AND ACCEPTED, as of

the date first above written:

MERRILL LYNCH, PIERCE, FENNER & SMITH

INCORPORATED
CITIGROUP GLOBAL MARKETS INC.
UBS SECURITIES LLC
WELLS FARGO SECURITIES, LLC

By:	Merrill Lynch, Pierce, Fenner & Smith			By:	Citigroup Global Markets Inc.
	Incorporated


By	/s/ Shawn Cepeda			By	/s/ Matthew J. Greenberger
		Name:	Shawn Cepeda			Name:	Matthew J. Greenberger
		Title:	Managing Director			Title:	Managing Director

By:	UBS Securities LLC			By:	Wells Fargo Securities, LLC


By	/s/ Demetrios Tsapralis			By	/s/ Carolyn Hurley
		Name:	Demetrios Tsapralis			Name:	Carolyn Hurley
		Title:	Executive Director			Title:	Director


By	/s/ Matthew Baldwin
		Name:	Matthew Baldwin
		Title:	Associate Director

For themselves and as Representatives of the other Underwriters named in Schedule A hereto.

SCHEDULE A

Name of Underwriter		Number of Initial Shares

Merrill Lynch, Pierce, Fenner & Smith Incorporated		1,688,800
Citigroup Global Markets Inc.		1,688,800
UBS Securities LLC		1,688,800
Wells Fargo Securities, LLC		1,688,800
Morgan Stanley & Co. Incorporated		1,688,800
BB&T Capital Markets, a division of Scott & Stringfellow, LLC		377,000
Jefferies & Company, Inc.		377,000
RBC Capital Markets, LLC		377,000
Janney Montgomery Scott LLC		50,000
Keefe, Bruyette & Woods, Inc.		50,000
Oppenheimer & Co. Inc.		50,000
Robert W. Baird & Co. Incorporated		50,000
BBVA Securities Inc.		25,000
BNY Mellon Capital Markets, LLC		25,000
Comerica Securities, Inc.		25,000
JMP Securities LLC		25,000
Mitsubishi UFJ Securities (USA), Inc.		25,000
PNC Capital Markets LLC		25,000
Santander Investment Securities Inc.		25,000
SMBC Nikko Capital Markets Limited		25,000
Southwest Securities, Inc.		25,000

Total		10,000,000

SCHEDULE B

Schedule of Issuer Free Writing Prospectus included in the General Disclosure Package

1. Final Term Sheet (attached hereto)

Filed Pursuant to Rule 433

Issuer Free Writing Prospectus

Dated May 26, 2011

Registration Statement No. 333-159995

Relating to Preliminary Prospectus Supplement

Dated May 25, 2011 to Prospectus Dated June 15, 2009

COMMONWEALTH REIT

7¼% Series E Cumulative Redeemable Preferred Shares
(Liquidation Preference $25.00 per share)

FINAL PRICING TERMS

Issuer:	CommonWealth REIT

Title of Shares:	7¼% Series E Cumulative Redeemable Preferred Shares

Number of Shares:	10,000,000 shares

Overallotment Option:	The underwriters may also purchase from us up to an additional 1,500,000 Series E Preferred Shares, at the public offering price, less the underwriting discount payable by the Issuer, within 30 days from the date of the prospectus supplement to cover overallotments, if any.

Maturity:	Perpetual (unless redeemed by the Issuer on and after May 15, 2016 or pursuant to its optional redemption rights or converted by an investor in connection with certain changes of control)

Expected Ratings:

	A securities rating is not a recommendation to buy, sell or hold securities and may be subject to revision or withdrawal at any time.

Trade Date:	May 26, 2011

Settlement Date:	June 1, 2011 (T+3)

Distribution Rate:	7.25% per year of the $25.00 per share liquidation preference (equivalent to $1.8125 per year per share)

Distribution Payment Dates:	The 15th day of each February, May, August and November beginning on August 15, 2011.

Conversion Rights:	Upon the occurrence of a Change of Control, each holder of Series E Preferred Shares will have the right (unless, prior to the Change of Control Conversion Date, we have provided or provide notice of our election to redeem the Series E Preferred Shares) to convert some or all of the Series E Preferred Shares held by such holder, or the Change of Control Conversion Right, on the Change of Control Conversion Date into a number of the Issuer’s common shares per Series E Preferred Share to be converted equal to the lesser of:

	· the quotient obtained by dividing (i) the sum of the $25.00 liquidation preference plus the amount of any accrued and

	unpaid distributions to but excluding the Change of Control Conversion Date (unless the Change of Control Conversion Date is after a record date for a Series E Preferred Share distribution payment and prior to the corresponding Series E Preferred Share distribution payment date, in which case no additional amount for such accrued and unpaid distribution will be included in this sum) by (ii) the Common Share Price; and

	· 1.967 (the Share Cap), subject to certain adjustments;

	subject, in each case, to provisions for the receipt of alternative consideration as described in this prospectus supplement.

	If prior to the Change of Control Conversion Date the Issuer has provided or provides a redemption notice, whether pursuant to its special optional redemption right in connection with a Change of Control or its optional redemption right, holders of Series E Preferred Shares will not have any right to convert the Series E Preferred Shares in connection with the Change of Control Conversion Right and any Series E Preferred Shares subsequently selected for redemption that have been tendered for conversion will be redeemed on the related date of redemption instead of converted on the Change of Control Conversion Date.

	A “Change of Control” is when, after the original issuance of the Series E Preferred Shares, the following have occurred and are continuing:

	· the acquisition by any person, including any syndicate or group deemed to be a “person” under Section 13(d)(3) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, of beneficial ownership, directly or indirectly, through a purchase, merger or other acquisition transaction or series of purchases, mergers or other acquisition transactions of the Issuer’s shares entitling that person to exercise more than 50% of the total voting power of all shares of the Issuer entitled to vote generally in elections of trustees (except that such person will be deemed to have beneficial ownership of all securities that such person has the right to acquire, whether such right is currently exercisable or is exercisable only upon the occurrence of a subsequent condition); and

	· following the closing of any transaction referred to in the bullet point above, neither the Issuer nor the acquiring or surviving entity has a class of common securities (or ADRs representing such securities) listed on the NYSE, the NYSE Amex or NASDAQ or listed or quoted on an exchange or quotation system that is a successor to the NYSE, the NYSE Amex or NASDAQ.

	The “Change of Control Conversion Date” will be a business day that is no fewer than 20 days nor more than 35 days after the date on which the Issuer provides the required notice of the

	occurrence of a Change of Control to the holders of Series E Preferred Shares.

	The “Common Share Price” will be: (i) the amount of cash consideration per common share, if the consideration to be received in the Change of Control by the holders of our common shares is solely cash; and (ii) the average of the closing prices for the Issuer’s common shares on the NYSE for the ten consecutive trading days immediately preceding but excluding the effective date of the Change of Control, if the consideration to be received in the Change of Control by the holders of the Issuer’s common shares is other than solely cash.

Optional Redemption:	On and after May 15, 2016, the Issuer may, at its option, redeem the Series E Preferred Shares, in whole or from time to time in part, for cash by paying $25.00 per share, plus any accrued and unpaid distributions to but excluding the date of redemption (subject to the special optional redemption right described below).

Special Optional Redemption:	Upon the occurrence of a Change of Control, the Issuer may, at its option, redeem the Series E Preferred Shares, in whole or in part and within 120 days after the first date on which such Change of Control occurred, by paying $25.00 per share, plus any accrued and unpaid distributions to but excluding the date of redemption. If, prior to the Change of Control Conversion Date, the Issuer has provided or provides notice of redemption with respect to the Series E Preferred Shares (whether pursuant to the Issuer’s optional redemption right or its special optional redemption right), investors will not have the Change of Control Conversion Right described above.

Public Offering Price:	$25.00 per share

Purchase Price by Underwriters:	$24.2125 per share

Net Proceeds (before expenses):	$242,125,000 ($278,443,750, if the underwriters exercise their overallotment option)

Joint Book-Running Managers:	Merrill Lynch, Pierce, Fenner & Smith Incorporated Citigroup Global Markets Inc. UBS Securities LLC Wells Fargo Securities, LLC

Lead Manager:	Morgan Stanley & Co. Incorporated

Co-Managers:	BB&T Capital Markets, a division of Scott & Stringfellow, LLC Jefferies & Company, Inc. RBC Capital Markets, LLC

Expected Listing/Symbol:	NYSE / “CWH PRE”

ISIN:	US2032336065

CUSIP:	203233 606

The issuer has filed a registration statement (including a prospectus dated June 15, 2009 and a preliminary prospectus supplement dated May 25, 2011) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement, the related preliminary prospectus supplement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in the offering will arrange to send you the prospectus and preliminary prospectus supplement if you request it by calling BofA Merrill Lynch toll-free at 1-800-294-1322, Citi toll-free at (800) 831-9146, UBS Investment Bank toll-free at (877) 827-6444 extension 561-3884 or Wells Fargo Securities toll-free at 1-800-326-5897.

Exhibit 3.1

COMMONWEALTH REIT

ARTICLES SUPPLEMENTARY

7 1 / 4 % SERIES E CUMULATIVE REDEEMABLE PREFERRED SHARES

$0.01 par value per share

COMMONWEALTH REIT, a Maryland real estate investment trust (the “ Trust ”), having its principal office in Newton, Massachusetts, hereby certifies to the State Department of Assessments and Taxation of Maryland that:

FIRST: Pursuant to authority expressly vested in the Board of Trustees of the Trust (the “ Board ”) by Section 6.1 of the Third Amendment and Restatement of Declaration of Trust of the Trust, dated July 1, 1994, as amended and supplemented (the “ Declaration ”), the Board has duly reclassified and designated 9,200,000 authorized but unissued Series A Preferred Shares (as defined in the Declaration) and 2,300,000 authorized but unissued Series B Preferred Shares (as defined in the Declaration) as 11,500,000 7 1 / 4 % Series E Cumulative Redeemable Preferred Shares, $0.01 par value per share, of the Trust (“ Series E Preferred Shares ”).

SECOND: The preferences, rights, voting powers, restrictions, limitations as to dividends and other distributions, qualifications and terms or conditions of redemption of the Series E Preferred Shares are as follows, which upon any restatement of the Declaration shall be made part of Article VI of the Declaration, with any necessary or appropriate changes to the enumeration or lettering of sections or subsections hereof. Capitalized terms used in this ARTICLE SECOND which are defined in the Declaration and not otherwise defined herein are used herein as so defined in the Declaration.

7 1 / 4 % Series E Cumulative Redeemable Preferred Shares, $0.01 par value per share

1. Designation and Number . A series of Preferred Shares, designated the 7 1 / 4 % Series E Cumulative Redeemable Preferred Shares, $0.01 par value per share (the “ Series E Preferred Shares ”), is hereby established. The number of authorized Series E Preferred Shares is 11,500,000.

2. Relative Seniority . In respect of rights to receive dividends and to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust, the Series E Preferred Shares shall rank (i) senior to the Common Shares, the Junior Participating Preferred Shares and any other class or series of Shares of the Trust, the terms of which specifically provide that such class or series ranks, as to rights to receive dividends and to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust, junior to the Series E Preferred Shares (the Shares described in this clause (i) being, collectively, “ Junior Shares ”), (ii) on a parity with the 7 1 / 8 % Series C Cumulative Redeemable Preferred Shares, $0.01 par value per share (the “ Series C Preferred Shares ”), the 6 1 / 2 % Series D Cumulative Convertible Preferred Shares, $0.01 par value per share (the “ Series D Preferred Shares ”), and any other class or series of Shares of the Trust, the terms of which specifically provide that such class or series ranks, as to rights to receive dividends and to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust,

on a parity with the Series E Preferred Shares, and (iii) junior to any class or series of Shares of the Trust, the terms of which specifically provide that such class or series ranks, as to rights to receive dividends and to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust, senior to the Series E Preferred Shares. For the avoidance of doubt, debt securities of the Trust which are convertible into or exchangeable for Shares of the Trust or any other debt securities of the Trust do not constitute a class or series of Shares for purposes of this Section 2.

3. Dividends and Distributions .

(a) Subject to the preferential rights of the holders of any class or series of Shares of the Trust ranking senior to the Series E Preferred Shares as to dividends, the holders of the then outstanding Series E Preferred Shares shall be entitled to receive, when and as authorized by the Board and declared by the Trust, out of any funds legally available therefor, cumulative dividends at a rate of seven and one quarter percent (7 1 / 4 % ) per annum of the twenty-five dollars ($25.00) per share liquidation preference of the Series E Preferred Shares (equivalent to the annual rate of $1.8125 per share) (the “ Dividend Rate ”). Such dividends shall accrue and be cumulative from the first date on which any Series E Preferred Shares are issued (the “ Original Issue Date ”), in the case of Series E Preferred Shares issued on such date, and otherwise from the date of the original issuance thereof, and will be payable quarterly in arrears in cash on the fifteenth day of each February, May, August and November beginning on August 15, 2011 (each such day being hereinafter called a “ Quarterly Dividend Date ”); provided that if any Quarterly Dividend Date is not a Business Day (as hereinafter defined), then the dividend which would otherwise have been payable on such Quarterly Dividend Date may be paid on the next succeeding Business Day with the same force and effect as if paid on such Quarterly Dividend Date, and no interest or additional dividends or other sums shall accrue on the amount so payable from such Quarterly Dividend Date to such next succeeding Business Day. As used herein, the term “ Dividend Period ” for Series E Preferred Shares means the period from the Original Issue Date or other date of the original issuance thereof, as applicable, and ending on and excluding the next following Quarterly Dividend Date, and each subsequent period from a Quarterly Dividend Date and ending on and excluding the next following Quarterly Dividend Date. The amount of any dividend payable for any full Dividend Period or portion thereof shall be computed on the basis of a 360-day year consisting of twelve 30-day months (it being understood that the first Dividend Period is shorter than a full Dividend Period). Dividends shall be payable to holders of record as they appear in the share records of the Trust at the close of business on the applicable record date (the “ Record Date ”), which shall be a date designated by the Board for the payment of dividends that is not more than 60 nor less than 10 days prior to the applicable Quarterly Dividend Date.

(b) Dividends on the Series E Preferred Shares shall accrue and be cumulative, whether or not (i) the Trust has earnings, (ii) there are funds legally available for the payment of such dividends or (iii) such dividends have been declared.

(c) If Series E Preferred Shares are outstanding, no full dividends (other than in Common Shares or other Junior Shares or options, warrants or rights to subscribe for or purchase Common Shares or other Junior Shares) shall be declared or paid or set aside for payment on any other class or series of Shares of the Trust ranking, as to dividends, on a parity

with the Series E Preferred Shares for any period, unless the full cumulative dividends on the Series E Preferred Shares have been or contemporaneously are declared and paid or declared and a sum sufficient for the payment thereof set aside for payment for all past Dividend Periods. When dividends are not paid in full (or a sum sufficient for such full payment is not so set aside) upon the Series E Preferred Shares and the Shares of any other class or series ranking on a parity as to dividends with the Series E Preferred Shares, all dividends declared upon Series E Preferred Shares and any such other class or series of Shares shall be allocated pro rata so that the amount of dividends declared per share on the Series E Preferred Shares and such other class or series of Shares shall in all cases bear to each other the same ratio that the accrued dividends per share on the Series E Preferred Shares and such other class or series of Shares (which shall not include any accumulation in respect of unpaid dividends for prior dividend periods if such other class or series does not have a cumulative dividend) bear to each other.

(d) Unless full cumulative dividends on the Series E Preferred Shares have been or contemporaneously are declared and paid or declared and a sum sufficient for the payment thereof set aside for payment for all past Dividend Periods, no dividends (other than in Common Shares or other Junior Shares or options, warrants or rights to subscribe for or purchase Common Shares or other Junior Shares) shall be declared or paid or set aside for payment and no other distribution shall be declared or made upon the Common Shares or any other Shares ranking junior to the Series E Preferred Shares as to rights to receive dividends or to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust, nor shall any Common Shares or any other such Shares be redeemed, purchased or otherwise acquired for any consideration (or any moneys be paid to or made available for a sinking fund for the redemption of any such Shares) by the Trust except (i) by conversion into or exchange for Common Shares or other Junior Shares, (ii) pursuant to pro rata offers to purchase or a concurrent redemption of all, or a pro rata portion of, the outstanding Series E Preferred Shares and any other class or series of Shares ranking on a parity with Series E Preferred Shares as to rights to receive dividends and to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust, (iii) by redemption, purchase or other acquisition of Common Shares made for purposes of an incentive, benefit or share purchase plan of the Trust or any of its subsidiaries for officers, Trustees or employees or others performing or providing similar services, (iv) by redemption, purchase or other acquisition of rights to purchase Junior Participating Preferred Shares pursuant to the Renewed Rights Agreement, dated as of March 10, 2004, between the Trust and Wells Fargo Bank, National Association (as successor rights agent to EquiServe Trust Company, N.A.), as rights agent, or pursuant to any replacement agreement therefor relating to such rights, each as in effect from time to time, or of any similar rights from time to time issued by the Trust in connection with a successor or supplemental shareholder rights protection plan adopted by the Board, and (v) for redemptions, purchases or other acquisitions by the Trust, whether pursuant to any provision of the Declaration, the bylaws of the Trust or otherwise, for the purpose of preserving the Trust’s status as a real estate investment trust (a “ REIT ”) for federal income tax purposes.

(e) No interest, or sum of money in lieu thereof, shall be payable in respect of any dividend payment or payments on Series E Preferred Shares which may be in arrears, and the holders of Series E Preferred Shares are not entitled to any dividends, whether payable in cash, securities or other property, in excess of the full cumulative dividends described in this

Section 3. Except as otherwise expressly provided herein, the Series E Preferred Shares shall not be entitled to participate in the earnings or assets of the Trust.

(f) Any dividend payment made on the Series E Preferred Shares shall be first credited against the earliest accrued but unpaid dividend due with respect to such Shares which remains payable. Any cash dividends paid in respect of Series E Preferred Shares, including any portion thereof which the Trust elects to designate as “capital gain dividends” (as defined in Section 857 (or any successor provision) of the Internal Revenue Code) or as a return of capital, shall be credited to the cumulative dividends on the Series E Preferred Shares.

(g) No dividends on the Series E Preferred Shares shall be authorized by the Board or be paid or set aside for payment by the Trust at such time as the terms and provisions of any agreement of the Trust, including any agreement relating to its indebtedness, directly or indirectly prohibit authorization, payment or setting aside for payment or provide that such authorization, payment or setting aside for payment would constitute a breach thereof or a default thereunder, or if such declaration, payment or setting aside for payment shall be restricted or prohibited by law.

(h) The Trust shall remain entitled to receive and retain any interest or other earnings on any money set aside for the payment of dividends on Series E Preferred Shares and holders thereof shall have no claim to such interest or other earnings. Any funds for the payment of dividends on Series E Preferred Shares which have been set apart by the Trust and which remain unclaimed by the holders of the Series E Preferred Shares entitled thereto on the first anniversary of the applicable Quarterly Dividend Date, or other dividend payment date, shall revert and be repaid to the general funds of the Trust, and thereafter the holders of the Series E Preferred Shares entitled to the funds which have reverted or been repaid to the Trust shall look only to the general funds of the Trust for payment, without interest or other earnings thereon.

(i) “ Business Day ” shall mean any day, other than a Saturday or Sunday, that is neither a legal holiday nor a day on which banking institutions in New York, New York or Boston, Massachusetts are authorized or required by law, regulation or executive order to close.

4. Liquidation Rights .

(a) Upon any voluntary or involuntary liquidation, dissolution or winding up of the Trust, before any distribution or payment shall be made to the holders of any Common Shares or any other Shares ranking junior to the Series E Preferred Shares as to rights to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust, but subject to the preferential rights of holders of any class or series of Shares ranking senior to the Series E Preferred Shares as to rights to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust, the holders of Series E Preferred Shares shall be entitled to receive, out of assets of the Trust legally available for distribution to shareholders, liquidating distributions in cash or property at its fair market value as determined by the Board in the amount of twenty-five dollars ($25.00) per Series E Preferred Share, plus an amount equal to all dividends accrued and unpaid thereon (whether or not declared).

(b) After payment of the full amount of the liquidating distributions to which they are entitled, the holders of Series E Preferred Shares will have no right or claim to any of the remaining assets of the Trust.

(c) In the event that upon any voluntary or involuntary liquidation, dissolution or winding up of the Trust, the available assets of the Trust are insufficient to pay the full amount of the liquidating distributions on all outstanding Series E Preferred Shares and the full amounts payable as liquidating distributions on all Shares of other classes or series of Shares of the Trust ranking on a parity with the Series E Preferred Shares as to rights to participate in distributions or payments in the event of any liquidation, dissolution or winding up of the Trust, then the holders of the Series E Preferred Shares and all other such classes or series of Shares shall share ratably in any such distribution of assets in proportion to the full liquidating distributions to which they would otherwise be respectively entitled.

(d) For purposes of this Section 4, neither the sale, lease or conveyance of all or substantially all of the property or business of the Trust, nor the merger or consolidation of the Trust into or with any other entity or the merger or consolidation of any other entity into or with the Trust or a statutory share exchange by the Trust, shall be deemed to be a dissolution, liquidation or winding up of the Trust.

(e) In determining whether a distribution (other than upon voluntary or involuntary dissolution), by dividend, redemption or other acquisition of Shares or otherwise, is permitted under Maryland law, amounts that would be needed, if the Trust were to be dissolved at the time of the distribution, to satisfy the preferential rights upon dissolution of the holders of Series E Preferred Shares will not be added to the Trust’s total liabilities.

5. Redemption by the Trust .

(a) Optional Redemption . The Series E Preferred Shares are not redeemable prior to May 15, 2016, except as otherwise provided in Section 5(b) or Section 5(c) below. On and after May 15, 2016, the Trust may, at its option, redeem Series E Preferred Shares in whole or from time to time in part, for cash at a redemption price per share of twenty-five dollars ($25.00), together with all accrued and unpaid dividends to (but excluding) the date fixed for redemption, except as otherwise provided in Section 5(d)(vi) below, and without interest (the “ Series E Redemption Price ”). Each date fixed for redemption of Series E Preferred Shares pursuant to this Section 5(a) or to Section 5(b) or 5(c) below is referred to in these provisions of the Series E Preferred Shares as a “ Series E Redemption Date .” The Series E Preferred Shares have no stated maturity and are not subject to any sinking fund or mandatory redemption. Any redemption of Series E Preferred Shares pursuant to this Section 5(a) shall be made in accordance with the applicable provisions of Section 5(d) below.

(b) Excess Series E Preferred Share Optional Redemption . The Trust may, at its option, redeem at any time all or from time to time any Series E Preferred Shares which constitute Excess Series E Preferred Shares (as defined in Section 9 below) for cash at a redemption price per share equal to the lesser of (i) Series E Redemption Price or (ii) the purchase price therefor specified in Section 6.14(c)(i) of the Declaration (giving effect to the provisions of Section 9(b) below), subject, with respect to the portion of the Series E

Redemption Price constituting accrued and unpaid dividends to (but excluding) the date fixed for redemption, to Section 5(d)(vi) below, and without interest. The Trust’s right to redeem Excess Series E Preferred Shares shall be in addition to, and shall not limit, its rights with respect to such Series E Preferred Shares set forth in Section 9 below, in Section 6.14 of the Declaration or in the bylaws of the Trust. Any redemption of Series E Preferred Shares pursuant to this Section 5(b) shall be made in accordance with the applicable provisions of Section 5(d) below.

(c) Special Optional Redemption by the Trust . Upon the occurrence of a Change of Control (as defined below), the Trust will have the option to redeem the Series E Preferred Shares, in whole or in part within 120 days after the first date on which such Change of Control occurred, for cash at twenty-five dollars ($25.00) per share, plus accrued and unpaid distributions, if any, to but excluding the redemption date (“ Special Optional Redemption Right ”). If, prior to the Change of Control Conversion Date (as defined below), the Trust has provided or provides notice of redemption with respect to the Series E Preferred Shares (whether pursuant to the Special Optional Redemption Right or other redemption rights pursuant to this Section 5), the holders of Series E Preferred Shares will not have the conversion right described below in Section 7. Any redemption of Series E Preferred Shares pursuant to this Section 5(c) shall be made in accordance with the applicable provisions of Section 5(d) below.

A “ Change of Control ” is when, after the original issuance of the Series E Preferred Shares, the following have occurred and are continuing:

(i) the acquisition by any person, including any syndicate or group deemed to be a “person” under Section 13(d)(3) of the Securities Exchange Act of 1934, as amended, of beneficial ownership, directly or indirectly, through a purchase, merger or other acquisition transaction or series of purchases, mergers or other acquisition transactions of shares of the Trust entitling that person to exercise more than 50% of the total voting power of all shares of the Trust entitled to vote generally in elections of trustees (except that such person will be deemed to have beneficial ownership of all securities that such person has the right to acquire, whether such right is currently exercisable or is exercisable only upon the occurrence of a subsequent condition), and

(ii) following the closing of any transaction referred to in (i) above, neither the Trust nor the acquiring or surviving entity has a class of common securities (or American Depositary Receipts representing such securities) listed on the New York Stock Exchange (the “ NYSE ”), the NYSE Amex Equities (the “ NYSE Amex ”), or the NASDAQ Stock Market (“ NASDAQ ”), or listed or quoted on an exchange or quotation system that is a successor to the NYSE, the NYSE Amex or NASDAQ.

(d) Procedures and Terms for Redemption .

(i) Notice of redemption will be mailed at least 30 days but not more than 60 days before the Series E Redemption Date to each holder of record of Series E Preferred Shares to be redeemed at the address shown on the share transfer books of the Trust; provided that if the Trust shall have reasonably concluded, based on advice of independent tax counsel experienced in such matters, that a redemption pursuant to Section 5(b) must be made on a date (the “ Excess Series E Preferred Share Redemption

Date ”) which is earlier than 30 days after the date of such mailing in order to preserve the status of the Trust as a REIT for federal income tax purposes or to comply with federal tax laws relating to the Trust’s qualification as a REIT, then the Trust may give such shorter notice as is necessary to effect such redemption on the Excess Series E Preferred Share Redemption Date. Each notice of redemption shall state: (A) the applicable Series E Redemption Date; (B) the number of Series E Preferred Shares to be redeemed; (C) the applicable Series E Redemption Price; (D) the place or places where certificates for such Series E Preferred Shares, to the extent Series E Preferred Shares are certificated, are to be surrendered for payment of the Series E Redemption Price; and (E) that dividends on the Series E Preferred Shares to be redeemed will cease to accrue on such Series E Redemption Date. In the case of an exercise of the Special Optional Redemption Right, such notice of redemption shall also state: (1) that the Series E Preferred Shares are being redeemed pursuant to the Special Optional Redemption Right in connection with the occurrence of a Change of Control and a brief description of the transaction or transactions constituting such Change of Control; and (2) that holders of the Series E Preferred Shares to which the notice relates will not be able to tender such Series E Preferred Shares for conversion in connection with the Change of Control and each Series E Preferred Share tendered for conversion that is selected, prior to the Change of Control Conversion Date, for redemption will be redeemed on the related redemption date instead of converted on the Change of Control Conversion Date. If fewer than all the Series E Preferred Shares are to be redeemed, the notice mailed to each such holder thereof shall also specify the number of Series E Preferred Shares to be redeemed from each such holder or the method for calculating that number. No failure to give such notice or any defect therein or in the mailing thereof shall affect the validity of the proceedings for the redemption of any Series E Preferred Shares except as to the holder to whom the Trust has failed to give notice or to whom notice was defective.

(ii) If notice of redemption of Series E Preferred Shares has been mailed in accordance with Section 5(d)(i) above and if the funds necessary for such redemption have been set aside by the Trust in trust for the benefit of the holders of the Series E Preferred Shares so called for redemption, subject to the provisions of Section 5(d)(v) below, then from and after the Series E Redemption Date specified in the notice, dividends will cease to accumulate, and such Shares shall no longer be deemed to be outstanding and shall not have the status of Series E Preferred Shares and all rights of the holders thereof as shareholders of the Trust (except the right to receive the Series E Redemption Price) shall terminate.

(iii) To the extent Series E Preferred Shares are certificated, upon surrender, in accordance with the Trust’s notice of redemption, of the certificates for any Series E Preferred Shares redeemed (properly endorsed or assigned for transfer and with applicable signature guarantees, if the Trust shall so require and the notice shall so state), such Series E Preferred Shares shall be redeemed by the Trust at the Series E Redemption Price. In case fewer than all the Series E Preferred Shares evidenced by any such certificate are redeemed, a new certificate or certificates shall be issued evidencing the unredeemed Series E Preferred Shares without cost to the holder thereof. In the event that Series E Preferred Shares to be redeemed are uncertificated, such shares shall be

redeemed in accordance with the notice and the applicable procedures of any depository and no further action on the part of the holders of such shares shall be required.

(iv) If fewer than all of the outstanding Series E Preferred Shares are to be redeemed, the number of Series E Preferred Shares to be redeemed will be determined by the Trust and such Shares may be redeemed pro rata from the holders of record of such Shares in proportion to the number of such Shares held by such holders (with adjustments to avoid redemption of fractional Shares), by lot or by any other equitable method determined by the Trust.

(v) Any funds for the redemption of Series E Preferred Shares which have been set aside by the Trust pursuant to Section 5(d)(ii) above, shall be irrevocably set aside separate and apart from the Trust’s other funds in trust for the pro rata benefit of the holders of the Series E Preferred Shares called for redemption, except that:

(A) the Trust shall be entitled to receive any interest or other earnings, if any, earned on any money so set aside in trust, and the holders of any Shares redeemed shall have no claim to such interest or other earnings; and

(B) any balance of monies deposited by the Trust and unclaimed by the holders of the Series E Preferred Shares entitled thereto at the expiration of one year from the applicable Series E Redemption Date shall be repaid, together with any interest or other earnings earned thereon, to the general funds of the Trust, and after any such repayment, the holders of the Shares entitled to the funds which have been repaid to the Trust shall look only to the general funds of the Trust for payment without interest or other earnings thereon.

(vi) Anything in these provisions of the Series E Preferred Shares to the contrary notwithstanding, the holders of record of Series E Preferred Shares at the close of business on a Record Date will be entitled to receive the dividend payable with respect to such Shares on the corresponding Quarterly Dividend Date notwithstanding the redemption of such Shares after such Record Date and on or prior to such Quarterly Dividend Date or the Trust’s default in the payment of the dividend due on such Quarterly Dividend Date, in which case the amount payable upon redemption of such Series E Preferred Shares will not include such dividend (and the full amount of the dividend payable for the applicable Dividend Period shall instead be paid on such Quarterly Dividend Date to the holders of record on such Record Date as aforesaid). Except as provided in this clause (vi) and except to the extent that accrued and unpaid dividends are payable as a part of the Series E Redemption Price pursuant to Section 5(a) or 5(b), the Trust will make no payment or allowance for unpaid dividends, regardless of whether or not in arrears, on Series E Preferred Shares called for redemption.

(vii) Notwithstanding the foregoing, unless the full cumulative dividends on all Series E Preferred Shares shall have been or contemporaneously are declared and paid or declared and a sum sufficient for the payment thereof set aside for payment for all past Dividend Periods, no Series E Preferred Shares shall be redeemed

unless all outstanding Series E Preferred Shares are simultaneously redeemed; provided, however, that (i) the foregoing shall not prevent the redemption of Series E Preferred Shares pursuant to Section 5(b) above or the purchase or acquisition of Series E Preferred Shares pursuant to a purchase or exchange offer made on the same terms to holders of all outstanding Series E Preferred Shares, and (ii) the foregoing shall not in any respect limit the terms and provisions of Section 6.14 of the Declaration or Section 9 hereof or any provisions of the bylaws of the Trust providing for redemptions, purchases or other acquisitions of shares by the Trust for the purpose of preserving the Trust’s status as a REIT for federal income tax purposes. In addition, unless the full cumulative dividends on all outstanding Series E Preferred Shares have been or contemporaneously are declared and paid or declared and a sum sufficient for the payment thereof set aside for payment for all past Dividend Periods, the Trust shall not purchase or otherwise acquire directly or indirectly any Series E Preferred Shares (except by conversion into or exchange for Common Shares or other Junior Shares); provided, however, that (i) the foregoing shall not prevent the redemption of Series E Preferred Shares pursuant to Section 5(b) above or the purchase or acquisition of Series E Preferred Shares pursuant to a purchase or exchange offer made on the same terms to holders of all outstanding Series E Preferred Shares, and (ii) the foregoing shall not in any respect limit the terms and provisions of Section 6.14 of the Declaration or Section 9 hereof or any provisions of the bylaws of the Trust providing for redemptions, purchases or other acquisitions of shares by the Trust for the purpose of preserving the Trust’s status as a REIT for federal income tax purposes.

(viii) For the avoidance of doubt, the provisions of this Section 5 shall not limit any direct or indirect purchase or acquisition by the Trust of all or any Series E Preferred Shares on the open market (including in privately negotiated transactions), except as otherwise expressly provided in Section 5(d)(vii) above.

6. Voting Rights . Notwithstanding anything to the contrary contained in the Declaration, except as set forth below in this Section 6, the holders of the Series E Preferred Shares shall not be entitled to vote at any meeting of the shareholders for election of Trustees or for any other purpose or otherwise to participate in any action taken by the Trust or the shareholders thereof, or to receive notice of any meeting of shareholders (except for such notices as may be expressly required by law).

(a) At any time dividends on the Series E Preferred Shares shall be in arrears for six or more quarterly periods, whether or not the quarterly periods are consecutive, the holders of Series E Preferred Shares (voting separately as a class with all other series of Preferred Shares of the Trust upon which like voting rights have been conferred and are exercisable) will be entitled to vote for the election of two additional Trustees of the Trust at the next annual meeting of shareholders and for those or other replacement Trustees at each subsequent meeting (and the number of Trustees then constituting the Board will automatically increase by two, if not already increased by two by reason of the election of Trustees by the holders of such Preferred Shares), until all dividends accumulated on Series E Preferred Shares for the past Dividend Periods shall have been fully paid or declared and a sum sufficient for the payment thereof set aside for payment. For the avoidance of doubt, and by means of example, in the event dividends on the Series C Preferred Shares, the Series D Preferred Shares and Series E

Preferred Shares shall each be in arrears for six or more quarterly periods, the holders of Series D Preferred Shares, the Series D Preferred Shares and Series E Preferred Shares (and the holders of all other series of Preferred Shares of the Trust upon which like voting rights have been conferred and are exercisable) shall be entitled to vote for the election of two additional Trustees in the aggregate, not six or more additional Trustees.

(i) Upon the full payment of all such dividends accumulated on Series E Preferred Shares for the past Dividend Periods or the declaration in full thereof and the Trust’s setting aside a sum sufficient for the payment thereof, the right of the holders of Series E Preferred Shares to elect such two Trustees shall cease, and (unless there are one or more other series of Preferred Shares of the Trust upon which like voting rights have been conferred and are exercisable) the term of office of such Trustees previously so elected shall automatically terminate and the authorized number of Trustees of the Trust will thereupon automatically return to the number of authorized Trustees otherwise in effect, but subject always to the same provisions for the reinstatement and divestment of the right to elect two additional Trustees in the case of any such future dividend arrearage.

(ii) If at any time when the voting rights conferred upon the Series E Preferred Shares pursuant to this Section 7(a) are exercisable any vacancy in the office of a Trustee elected pursuant to this Section 7(a) shall occur, then such vacancy may be filled only by the written consent of the remaining such Trustee or by vote of the holders of record of the outstanding Series E Preferred Shares and any other series of Preferred Shares of the Trust upon which like voting rights have been conferred and are exercisable and which are entitled to vote as a class with the Series E Preferred Shares in the election of Trustees pursuant to this Section 7(a).

(iii) Any Trustee elected or appointed pursuant to this Section 7(a) may be removed only by the holders of the outstanding Series E Preferred Shares and any other series of Preferred Shares of the Trust upon which like voting rights have been conferred and are exercisable and which are entitled to vote as a class with the Series E Preferred Shares in the election of Trustees pursuant to this Section 7(a), and may not be removed by the holders of the Common Shares.

(iv) The term of any Trustees elected or appointed pursuant to this Section 7(a) shall be from the date of such election or appointment and their qualification until the next annual meeting of the shareholders and until their successors are duly elected and qualify, except as otherwise provided above in this Section 7(a).

(b) So long as any Series E Preferred Shares remain outstanding, the Trust shall not, without the affirmative vote or consent of the holders of at least two-thirds of the Series E Preferred Shares outstanding at the time, given in person or by proxy, either in writing or at a meeting (the holders of Series E Preferred Shares voting separately as a class), (i) authorize or create, or increase the number of authorized or issued shares of, any class or series of Shares ranking senior to the Series E Preferred Shares with respect to payment of dividends or the distribution of assets upon liquidation, dissolution or winding up of the Trust, or reclassify any authorized Shares of the Trust into any such Shares, or create, authorize or issue

any obligation or security convertible into or evidencing the right to purchase any such Shares, or (ii) amend, alter or repeal the provisions of the Declaration or the terms of the Series E Preferred Shares, whether by merger, consolidation or otherwise, so as to materially and adversely affect any right, preference, privilege or voting power of the Series E Preferred Shares; provided, however, for the avoidance of doubt that any increase in the number of authorized Preferred Shares, any issuance of or increase in the number of Series E Preferred Shares or any creation or issuance of or increase in the number of authorized shares of any class or series of Preferred Shares which rank on a parity with the Series E Preferred Shares with respect to payment of dividends or the distribution of assets upon liquidation, dissolution or winding up of the Trust or which are Junior Shares shall not be deemed to materially and adversely affect the rights, preferences, privileges or voting powers of the Series E Preferred Shares; and provided further, however , for the avoidance of doubt that, with respect to any merger, consolidation or similar event, so long as the Series E Preferred Shares remain outstanding with the terms thereof materially unchanged or the holders of shares of Series E Preferred Shares receive shares of the successor with substantially identical rights, taking into account that, upon the occurrence of such event, the Trust may not be the surviving entity, the occurrence of such event shall not be deemed to materially and adversely affect the rights, preferences, privileges or voting powers of the Series E Preferred Shares.

(c) The voting provisions set forth in clauses (a) and (b) above will not apply if, at or prior to the time when the act with respect to which a vote would otherwise be required shall be effected, all outstanding Series E Preferred Shares shall have been redeemed or called for redemption and sufficient funds shall have been deposited in trust pursuant to the provisions of Sections 5(d)(ii) and 5(d)(v) hereof to effect the redemption.

(d) On each matter submitted to a vote of the holders of Series E Preferred Shares or on which the holders of Series E Preferred Shares are otherwise entitled to vote as provided herein, each Series E Preferred Share shall be entitled to one vote, except that when Shares of any other class or series of Preferred Shares of the Trust have the right to vote with the Series E Preferred Shares as a single class on any matter, the Series E Preferred Shares and the Shares of each such other class or series will have one vote for each twenty-five dollars ($25.00) of liquidation preference.

7. Conversion . The Series E Preferred Shares are not convertible into or exchangeable for any other property or securities of the Trust, except as provided in this Section 7. This provision will not prevent the Trust from offering to convert or exchange the Series E Preferred Shares other than pursuant to this Section 7.

(a) Upon the occurrence of a Change of Control, each holder of Series E Preferred Shares shall have the right, unless, prior to the Change of Control Conversion Date, the Trust has provided or provides notice of its election to redeem the Series E Preferred Shares pursuant to Section 5 above to convert some or all of the Series E Preferred Shares held by such holder (the “ Change of Control Conversion Right ”) on the Change of Control Conversion Date into a number Common Shares per Series E Preferred Share to be converted (the “ Common Share Conversion Consideration ”) equal to the lesser of (A) the quotient obtained by dividing (i) the sum of (x) the twenty-five dollar ($25.00) liquidation preference plus (y) the amount of any accrued and unpaid distributions to but excluding the Change of Control Conversion Date

(unless the Change of Control Conversion Date is after a Distribution Record Date and prior to the corresponding Distribution Payment Date, in which case no additional amount for such accrued and unpaid distribution will be included in such sum) by (ii) the Common Share Price (as defined below) and (B) 1.967 (the “Share Cap”), subject to the immediately succeeding paragraph.

The Share Cap is subject to pro rata adjustments for any share splits (including those effected pursuant to a Common Share distribution), subdivisions or combinations (in each case, a “ Share Split ”) with respect to Common Shares as follows: the adjusted Share Cap as the result of a Share Split shall be the number of Common Shares that is equivalent to the product obtained by multiplying (i) the Share Cap in effect immediately prior to such Share Split by (ii) a fraction, the numerator of which is the number of Common Shares outstanding after giving effect to such Share Split and the denominator of which is the number of Common Shares outstanding immediately prior to such Share Split.

For the avoidance of doubt, subject to the immediately succeeding sentence, the aggregate number of Common Shares (or equivalent Alternative Conversion Consideration (as defined below), as applicable) issuable in connection with the exercise of the Change of Control Conversion Right shall not exceed 19,670,000 Common Shares (or equivalent Alternative Conversion Consideration, as applicable), subject to increase to the extent the underwriters’ over-allotment option to purchase additional Series E Preferred Stock in the initial public offering of Series E Preferred Stock is exercised, not to exceed 22,620,500 Common Shares in total (or equivalent Alternative Conversion Consideration, as applicable) (the “ Exchange Cap ”). The applicable Exchange Cap is subject to pro rata adjustments for any Share Splits on the same basis as the corresponding adjustment to the Share Cap.

In the case of a Change of Control pursuant to which Common Shares shall be converted into cash, securities or other property or assets (including any combination thereof) (the “ Alternative Form Consideration ”), a holder of Series E Preferred Shares shall receive upon conversion of such Series E Preferred Shares the kind and amount of Alternative Form Consideration which such holder of Series E Preferred Shares would have owned or been entitled to receive upon the Change of Control had such holder of Series E Preferred Shares held a number of Common Shares equal to the Common Share Conversion Consideration immediately prior to the effective time of the Change of Control (the “ Alternative Conversion Consideration ”; and the Common Share Conversion Consideration or the Alternative Conversion Consideration, as may be applicable to a Change of Control, shall be referred to herein as the “ Conversion Consideration ”).

In the event that holders of Common Shares have the opportunity to elect the form of consideration to be received in the Change of Control, the consideration that the holders of Series E Preferred Shares shall receive shall be the form of consideration elected by the holders of the Common Shares who participate in the determination (based on the weighted average of elections) and shall be subject to any limitations to which all holders of Common Shares are subject, including, without limitation, pro rata reductions applicable to any portion of the consideration payable in the Change of Control.

The “ Change of Control Conversion Date ” shall be a Business Day set forth in the notice of Change of Control provided in accordance with Section 7(c) below that is no less than 20 days nor more than 35 days after the date on which the Trust provides such notice pursuant to Section 7(c).

The “ Common Share Price ” shall be (i) the amount of cash consideration per Common Share, if the consideration to be received in the Change of Control by holders of Common Shares is solely cash, and (ii) the average of the closing prices per Common Share on the NYSE for the ten consecutive trading days immediately preceding but excluding the effective date of the Change of Control, if the consideration to be received in the Change of Control by holders of Common Shares is other than solely cash.

(b) At the election of the Trust, fractional Common Shares may be issued upon the conversion of Series E Preferred Shares. If such election is not made, in lieu of fractional shares, holders shall be entitled to receive the cash value of such fractional shares based on the Common Share Price.

(c) Within 15 days following the occurrence of a Change of Control, a notice of occurrence of the Change of Control, describing the resulting Change of Control Conversion Right, shall be delivered to the holders of record of the Series E Preferred Shares at their addresses as they appear on the Trust’s share transfer records and notice shall be provided to the Trust’s transfer agent. No failure to give such notice or any defect thereto or in the mailing thereof shall affect the validity of the proceedings for the conversion of any Series E Preferred Shares except as to the holder to whom notice was defective or not given. Each notice shall state: (i) the events constituting the Change of Control; (ii) the date of the Change of Control; (iii) the last date on which the holders of Series E Preferred Shares may exercise their Change of Control Conversion Right; (iv) the method and period for calculating the Common Share Price; (v) the Change of Control Conversion Date, which shall be a Business Day occurring within 20 to 35 days following the date of such notice; (vi) that if, prior to the Change of Control Conversion Date, the Trust has provided or provides notice of its election to redeem all or any portion of the Series E Preferred Shares, the holder will not be able to convert Series E Preferred Shares and such Series E Preferred Shares shall be redeemed on the related redemption date, even if they have already been tendered for conversion pursuant to the Change of Control Conversion Right; (vii) if applicable, the type and amount of Alternative Conversion Consideration entitled to be received per Series E Preferred Share; (viii) the name and address of the paying agent and the conversion agent; and (ix) the procedures that the holders of Series E Preferred Shares must follow to exercise the Change of Control Conversion Right.

(d) The Trust shall issue a press release for publication on the Dow Jones & Company, Inc., Business Wire, PR Newswire or Bloomberg Business News (or, if such organizations are not in existence at the time of issuance of such press release, such other news or press organization as is reasonably calculated to broadly disseminate the relevant information to the public), or post notice on the Trust’s website, in any event prior to the opening of business on the first Business Day following any date on which the Trust provides notice pursuant to Section 7(c) above to the holders of Series E Preferred Shares.

(e) In order to exercise the Change of Control Conversion Right, a holder of Series E Preferred Shares shall be required to deliver, on or before the close of business on the Change of Control Conversion Date, the certificates evidencing the Series E Preferred Shares, to the extent such shares are certificated, to be converted, duly endorsed for transfer, together with a written conversion notice completed, to the Trust’s transfer agent. Such notice shall state: (i) the relevant Change of Control Conversion Date; (ii) the number of Series E Preferred Shares to be converted; and (iii) that the Series E Preferred Shares are to be converted pursuant to the applicable terms of the Series E Preferred Shares. Notwithstanding the foregoing, if the Series E Preferred Shares are held in global form, such notice shall comply with applicable procedures of The Depository Trust Company (“DTC”).

(f) Holders of Series E Preferred Shares may withdraw any notice of exercise of a Change of Control Conversion Right (in whole or in part) by a written notice of withdrawal delivered to the Trust’s transfer agent prior to the close of business on the Business Day prior to the Change of Control Conversion Date. The notice of withdrawal must state: (i) the number of withdrawn Series E Preferred Shares; (ii) if certificated Series E Preferred Shares have been issued, the certificate numbers of the withdrawn Series E Preferred Shares; and (iii) the number of Series E Preferred Shares, if any, which remain subject to the conversion notice. Notwithstanding the foregoing, if the Series E Preferred Shares are held in global form, the notice of withdrawal shall comply with applicable procedures of DTC.

(g) Series E Preferred Shares as to which the Change of Control Conversion Right has been properly exercised and for which the conversion notice has not been properly withdrawn shall be converted into the applicable Conversion Consideration in accordance with the Change of Control Conversion Right on the Change of Control Conversion Date, unless, prior to the Change of Control Conversion Date, the Trust has provided or provides notice of its election to redeem such Series E Preferred Shares, whether pursuant to Section 5(a), 5(b) or 5(c) above. If the Trust elects to redeem Series E Preferred Shares that would otherwise be converted into the applicable Conversion Consideration on a Change of Control Conversion Date, such Series E Preferred Shares shall not be so converted, and the holders of such shares shall be entitled to receive on the applicable redemption date the applicable redemption price in accordance with the applicable provisions of Section 5 above.

(h) The Trust shall deliver the applicable Conversion Consideration no later than the third Business Day following the Change of Control Conversion Date.

(i) Notwithstanding anything to the contrary contained herein, no holder of Series E Preferred Shares will be entitled to convert such Series E Preferred Shares into Common Shares to the extent that receipt of such Common Shares would cause the holder of such Common Shares (or any other person) to beneficially own or constructively own, within the meaning of the Declaration or Bylaws, Common Shares in excess of any applicable share ownership limitation contained in the Declaration (including without limitation Section 6.14 thereof) or Bylaws, each as in effect from time to time.

8. Status of Redeemed and Reacquired Series E Preferred Shares . In the event any Series E Preferred Shares shall be redeemed pursuant to Section 5 hereof or otherwise reacquired

by the Trust, the Shares so redeemed or reacquired shall become authorized but unissued Series E Preferred Shares, available for future issuance and reclassification by the Trust.

9. Restrictions on Transfer .

(a) The Board, by notice to the holder thereof, may purchase any or all Series E Preferred Shares that have been transferred pursuant to a transfer which, in the opinion of the Board, would jeopardize the status of the Trust as a REIT for federal income tax purposes. Without limiting the generality of the foregoing, as a condition to the transfer and/or registration of transfer of any Series E Preferred Shares (“ Excess Series E Preferred Shares ”) which could result in direct or indirect ownership (as contemplated by Section 6.14(i) of the Declaration) of Series E Preferred Shares representing more than 9.8% in value of the total Series E Preferred Shares outstanding becoming concentrated in the hands of one owner other than an Excepted Person (as such term is defined in Section 6.14(c) of the Declaration), such potential owner shall file with the Trust the statement or affidavit described in Section 6.14(b) of the Declaration no later than the fifteenth day prior to any transfer, registration of transfer or transaction which, if consummated, would result in such ownership. The Board shall have the power and right (i) by lot or other means deemed equitable by them to call for the purchase from the beneficial owner or the holder of such Excess Series E Preferred Shares, and (ii) to refuse to transfer or issue Excess Series E Preferred Shares or share certificates to any Person (as such term is defined in Section 1.4(r) of the Declaration) whose acquisition of such Series E Preferred Shares would, in the opinion of the Board, result in the direct or indirect beneficial ownership of any Excess Series E Preferred Shares by a person other than any of the Excepted Persons.

(b) Any Excess Series E Preferred Shares shall automatically be deemed to constitute Excess Shares (as such term is defined in Section 6.14(c) of the Declaration) and shall be treated in the manner prescribed for Excess Shares, including, without limitation, the provisions set forth in Section 6.14(c) thereof.

(c) Notwithstanding any other provision of the Declaration or hereof to the contrary, any purported acquisition of Series E Preferred Shares (whether such purported acquisition results from the direct or indirect acquisition or ownership (as contemplated by the Declaration) of Series E Preferred Shares) which would result in the disqualification of the Trust as a REIT for federal income tax purposes, shall be null and void. Any such Series E Preferred Shares may be treated by the Board in the manner prescribed for Excess Series E Preferred Shares in these provisions of the Series E Preferred Shares and for Excess Shares in Section 6.14(c) of the Declaration.

(d) The provisions of this Section 9 shall not limit the applicability of Section 6.14 of the Declaration to Series E Preferred Shares in accordance with the terms thereof, and the provisions of this Section 9 and of Section 6.14 of the Declaration shall not limit the right of the Trust to elect to redeem Excess Series E Preferred Shares pursuant to Section 5(b) hereof. Nothing contained in this Section 9 or in any other provision of the Series E Preferred Shares shall limit the authority of the Board to take such other action as they deem necessary or advisable to protect the Trust and the interests of the shareholders by preservation of the Trust’s status as a REIT for federal income tax purposes. The provisions of subsections (g) through (i) of Section 6.14 of the Declaration shall be applicable to this Section 9

as though (i) the references therein to Section 6.14 of the Declaration referred instead to this Section 9 and (ii) the references therein to subsections of Section 6.14 of the Declaration referred to the comparable provisions of this Section 9.

10. Severability . If any preference, right, voting power, restriction, limitation as to dividends or other distributions, qualification, term or condition of redemption or other term of the Series E Preferred Shares is invalid, unlawful or incapable of being enforced by reason of any rule of law or public policy, then, to the extent permitted by law, all other preferences, rights, voting powers, restrictions, limitations as to dividends or other distributions, qualifications, terms and conditions of redemption and other terms of the Series E Preferred Shares which can be given effect without the invalid, unlawful or unenforceable preference, right, voting power, restriction, limitation as to dividends or other distributions, qualification, term or condition of redemption or other term of the Series E Preferred Shares shall remain in full force and effect and shall not be deemed dependent upon any invalid, unlawful or unenforceable preference, right, voting power, restriction, limitation as to dividends or other distributions, qualification, term or condition of redemption or other term of the Series E Preferred Shares.

THIRD: The Series E Preferred Shares have been classified and designated by the Board under the authority contained in the Declaration.

FOURTH: These Articles Supplementary have been approved by the Board in the manner and by the vote required by law.

FIFTH: The undersigned Treasurer and Chief Financial Officer of the Trust acknowledges these Articles Supplementary to be the trust act of the Trust and, as to all matters or facts required to be verified under oath, the undersigned Treasurer and Chief Financial Officer acknowledges that, to the best of his knowledge, information and belief, these matters and facts are true in all material respects and this statement is made under the penalties for perjury.

(Remainder of Page Intentionally Left Blank)

IN WITNESS WHEREOF, COMMONWEALTH REIT has caused these Articles Supplementary to be signed in its name and on its behalf by its Treasurer and Chief Financial Officer and witnessed by its Secretary on May 31, 2011.

WITNESS:		COMMONWEALTH REIT


By:	/s/ Jennifer B. Clark		By:	/s/ John C. Popeo
	Jennifer B. Clark			John C. Popeo
	Secretary			Treasurer and Chief Financial Officer

Exhibit 4.1

A MARYLAND REAL ESTATE INVESTMENT TRUST SEE REVERSE FOR IMPORTANT NOTICE ON TRANSFER RESTRICTIONS AND OTHER INFORMATION 203233 6 06 THIS CERTIFIES THAT is the registered holder of FULLY PAID AND NONASSESSABLE 7¼% SERIES E CUMULATIVE REDEEMABLE PREFERRED SHARES, $.01 PAR VALUE PER SHARE, OF BENEFICIAL INTEREST COMMONWEALTH REIT a Maryland real estate investment trust (the “Trust”), transferable on the books of the Trust by the holder hereof in person or by its duly authorized attorney upon surrender of this Certificate properly endorsed. This Certificate and the shares evidenced hereby are issued and shall be held subject to all of the provisions of the Declaration of Trust and Bylaws of the Trust and any amendments or supplements thereto. The holder of this Certificate and every transferee or assignee hereof by accepting or holding the same agrees to be bound by all of the provisions of the Declaration of Trust and Bylaws of the Trust, as amended or supplemented from time to time. This Certificate is not valid unless countersigned and registered by the Transfer Agent and Registrar. IN WITNESS WHEREOF, the Trust has caused this Certificate to be executed on its behalf by its duly authorized officers. Dated: PRESIDENT TREASURER COUNTERSIGNED AND REGISTERED: WELLS FARGO BANK, N.A. TRANSFER AGENT AND REGISTRAR BY AUTHORIZED SIGNATURE CWE AMERICAN FINANCIAL PRINTING INCORPORATED – MINNEAPOLIS THIS CERTIFICATE IS TRANSFERABLE IN SOUTH SAINT PAUL, MN. THE DECLARATION OF TRUST PROVIDES THAT THE NAME “COMMONWEALTH REIT” REFERS TO THE TRUSTEES UNDER THE DECLARATION OF TRUST, COLLECTIVELY AS TRUSTEES, BUT NOT INDIVIDUALLY OR PERSONALLY, AND NO TRUSTEE, SHAREHOLDER, EMPLOYEE OR AGENT OF THE TRUST SHALL BE HELD TO ANY PERSONAL LIABILITY, JOINTLY OR SEVERALLY, IN CONNECTION WITH THIS INSTRUMENT. ALL PERSONS DEALING WITH THE TRUST IN ANY WAY SHALL LOOK ONLY TO THE ASSETS OF THE TRUST FOR PAYMENT OF ANY SUM OR PERFORMANCE OF ANY OBLIGATION. 7¼% Series E Cumulative Redeemable Preferred Shares, $.01 par value per share 7¼% Series E Cumulative Redeemable Preferred Shares, $.01 par value per share

COMMONWEALTH REIT IMPORTANT NOTICE PURSUANT AND SUBJECT TO THE TERMS OF THE TRUST’S DECLARATION OF TRUST, A COPY OF WHICH, TOGETHER WITH ALL AMENDMENTS AND SUPPLEMENTS THERETO (THE “DECLARATION”), IS ON FILE WITH THE STATE DEPARTMENT OF ASSESSMENTS AND TAXATION OF MARYLAND, THE TRUST HAS THE AUTHORITY TO CREATE ONE OR MORE ADDITIONAL CLASSES OR SERIES OF SHARES AND ISSUE ADDITIONAL SHARES OF ANY EXISTING CLASS OR SERIES OF SHARES. THE TRUST WILL FURNISH A FULL STATEMENT OF (i) THE AUTHORITY OF THE TRUST TO CREATE ADDITIONAL CLASSES OR SERIES OF SHARES AND ISSUE ADDITIONAL SHARES OF ANY EXISTING CLASS OR SERIES OF SHARES, (ii) THE TERMS OF ANY EXISTING CLASS OR SERIES OF SHARES, AND (iii) SUCH OTHER INFORMATION AS IS REQUIRED BY SECTION 8-203(d) OF THE MARYLAND REIT LAW, WITHOUT CHARGE TO ANY SHAREHOLDER UPON REQUEST TO THE SECRETARY OF THE TRUST. THE SHARES EVIDENCED BY THIS CERTIFICATE ARE SUBJECT TO RESTRICTIONS ON OWNERSHIP AND TRANSFER WHICH ARE OR MAY HEREAFTER BE CONTAINED IN THE DECLARATION OR IN THE BYLAWS OF THE TRUST, AS AMENDED FROM TIME TO TIME (THE “BYLAWS”), INCLUDING PROVISIONS WHICH PROHIBIT THE OWNERSHIP OF MORE THAN 9.8% OF THE TRUST’S SECURITIES BY ANY PERSON OR GROUP. THIS DESCRIPTION OF THE RESTRICTIONS UPON OWNERSHIP OR TRANSFER OF THE TRUST’S SECURITIES IS NOT COMPLETE. A MORE COMPLETE DESCRIPTION OF THESE RESTRICTIONS APPEARS IN THE DECLARATION OR BYLAWS, AS APPLICABLE, COPIES OF WHICH WILL BE SENT WITHOUT CHARGE TO ANY SHAREHOLDER UPON REQUEST TO THE SECRETARY OF THE TRUST. The following abbreviations, when used in the inscription on the face of this Certificate, shall be construed as though they were written out in full according to applicable laws or regulations: TEN COM – as tenants in common UTMA – Custodian (Cust) (Minor) TEN ENT – as tenants by entireties under Uniform Transfers to Minors JT TEN – as joint tenants with right of survivorship Act and not as tenants in common (State) Additional abbreviations may also be used though not in above list. For value received hereby sell, assign, and transfer unto (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS INCLUDING ZIP CODE OF ASSIGNEE) Shares of beneficial interest represented by the within Certificate, and do hereby irrevocably constitute and appoint Attorney to transfer the said shares on the books of the within-named Trust with full power of substitution in the premises. Dated X X NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER. SIGNATURE GUARANTEED ALL GUARANTEES MUST BE MADE BY A FINANCIAL INSTITUTION (SUCH AS A BANK OR BROKER) WHICH IS A PARTICIPANT IN THE SECURITIES TRANSFER AGENTS MEDALLION PROGRAM (“STAMP”), THE NEW YORK STOCK EXCHANGE, INC. MEDALLION SIGNATURE PROGRAM (“MSP”), OR THE STOCK EXCHANGES MEDALLION PROGRAM (“SEMP”) AND MUST NOT BE DATED. GUARANTEES BY A NOTARY PUBLIC ARE NOT ACCEPTABLE. PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE

Exhibit 5.1

[LETTERHEAD OF VENABLE LLP]

May 26, 2011

CommonWealth REIT

Two Newton Place

255 Washington Street, Suite 300

Newton, Massachusetts 02458

Re: Registration Statement on Form S-3 (File No. 333-159995)

Ladies and Gentlemen:

We have served as Maryland counsel to CommonWealth REIT, a Maryland real estate investment trust (the “Company”), in connection with certain matters of Maryland law arising out of the issuance of up to 11,500,000 7 1 / 4 % Series E Cumulative Redeemable Preferred Shares, $.01 par value per share (the “Preferred Shares”), of the Company (including up to 1,500,000 Preferred Shares which the underwriters in the Offering (as defined herein) have the option to purchase solely to cover over-allotments), covered by the above-referenced Registration Statement, and all amendments thereto (the “Registration Statement”), filed by the Company with the United States Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “1933 Act”). The Preferred Shares are to be issued in an underwritten public offering (the “Offering”) pursuant to a Prospectus Supplement, dated May 26, 2011 (the “Prospectus Supplement”).

In connection with our representation of the Company, and as a basis for the opinion hereinafter set forth, we have examined originals, or copies certified or otherwise identified to our satisfaction, of the following documents (collectively, the “Documents”):

1. The Registration Statement and the related form of prospectus included therein;

2. The Prospectus Supplement, substantially in the form to be filed with the Commission;

3. The Amended and Restated Declaration of Trust, as amended and supplemented, of the Company (the “Declaration of Trust”), certified by the State Department of Assessments and Taxation of Maryland (the “SDAT”);

4. The form of Articles Supplementary relating to the Preferred Shares, substantially in the form to be filed by the Company with the SDAT (the “Articles Supplementary”), certified as of the date hereof by an officer of the Company;

5. The Amended and Restated Bylaws of the Company, certified as of the date hereof by an officer of the Company;

6. A certificate of the SDAT as to the good standing of the Company, dated as of a recent date;

7. Resolutions adopted by the Board of Trustees of the Company, or a duly authorized committee thereof, relating to, among other matters, the authorization of the issuance of the Preferred Shares (the “Resolutions”), certified as of the date hereof by an officer of the Company;

8. A certificate executed by an officer of the Company, dated as of the date hereof; and

9. Such other documents and matters as we have deemed necessary or appropriate to express the opinion set forth below, subject to the assumptions, limitations and qualifications stated herein.

In expressing the opinion set forth below, we have assumed the following:

1. Each individual executing any of the Documents, whether on behalf of such individual or another person, is legally competent to do so.

2. Each individual executing any of the Documents on behalf of a party (other than the Company) is duly authorized to do so.

3. Each of the parties (other than the Company) executing any of the Documents has duly and validly executed and delivered each of the Documents to which such party is a signatory, and such party’s obligations set forth therein are legal, valid and binding and are enforceable in accordance with all stated terms.

4. All Documents submitted to us as originals are authentic. The form and content of all Documents submitted to us as unexecuted drafts do not differ in any respect relevant to this opinion from the form and content of such Documents as executed and delivered. All Documents submitted to us as certified or photostatic copies conform to the original documents. All signatures on all such Documents are genuine. All public records reviewed or relied upon by us or on our behalf are true and complete. All representations, warranties, statements and information contained in the Documents are true and complete. There has been no oral or written modification of or amendment to any of the Documents, and there has been no waiver of any provision of any of the Documents, by action or omission of the parties or otherwise.

5. Prior to the issuance of any of the Preferred Shares, the Articles Supplementary will be filed with, and accepted for record by, the SDAT.

6. The Preferred Shares will not be issued in violation of any restriction or limitation contained in the Declaration of Trust or the Articles Supplementary.

Based upon the foregoing, and subject to the assumptions, limitations and qualifications stated herein, it is our opinion that:

1. The Company is a real estate investment trust duly formed and existing under and by virtue of the laws of the State of Maryland and is in good standing with the SDAT.

2. The issuance of the Preferred Shares has been duly authorized and, when issued and delivered by the Company pursuant to the Resolutions and the Registration Statement against payment of the consideration set forth therein, the Preferred Shares will be validly issued, fully paid and nonassessable.

The foregoing opinion is limited to the laws of the State of Maryland and we do not express any opinion herein concerning any other law. We express no opinion as to compliance with, or the applicability of, federal or state securities laws, including the securities laws of the State of Maryland, or as to federal or state laws regarding fraudulent transfers. To the extent that any matter as to which our opinion is expressed herein would be governed by the laws of any jurisdiction other than the State of Maryland, we do not express any opinion on such matter. The opinion expressed herein is subject to the effect of judicial decisions which may permit the introduction of parol evidence to modify the terms or the interpretation of agreements.

The opinion expressed herein is limited to the matters specifically set forth herein and no other opinion shall be inferred beyond the matters expressly stated. We assume no obligation to supplement this opinion if any applicable law changes after the date hereof or if we become aware of any fact that might change the opinion expressed herein after the date hereof.

This opinion is being furnished to you for submission to the Commission as an exhibit to the Company’s Current Report on Form 8-K relating to the Offering (the “Current Report”), which is incorporated by reference in the Registration Statement. We hereby consent to the filing of this opinion as an exhibit to the Current Report and the said incorporation by reference and to the use of the name of our firm therein. In giving this consent, we do not admit that we are within the category of persons whose consent is required by Section 7 of the 1933 Act.

	Very truly yours,

	/s/ Venable LLP

Exhibit 8.1

May 26, 2011

CommonWealth REIT

Two Newton Place

255 Washington Street, Suite 300

Newton, Massachusetts 02458

Ladies and Gentlemen:

The following opinion is furnished to CommonWealth REIT, a Maryland real estate investment trust (the “Company”), to be filed with the Securities and Exchange Commission (the “SEC”) as Exhibit 8.1 to the Company’s Current Report on Form 8-K to be filed within one week of the date hereof (the “Form 8-K”) under the Securities Exchange Act of 1934, as amended.

We have acted as counsel for the Company in connection with its Registration Statement on Form S-3, File No. 333-159995 (the “Registration Statement”), under the Securities Act of 1933, as amended (the “Securities Act”), and we have reviewed originals or copies of the Registration Statement, such corporate records, such certificates and statements of officers of the Company and of public officials, and such other documents as we have considered relevant and necessary in order to furnish the opinion hereinafter set forth. In doing so, we have assumed the genuineness of all signatures, the legal capacity of natural persons, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as copies, and the authenticity of the originals of such documents. Specifically, and without limiting the generality of the foregoing, we have reviewed: (i) the Company’s amended and restated declaration of trust, as amended and supplemented, and its amended and restated by-laws, as amended; (ii) the prospectus supplement dated May 26, 2011 (the “Prospectus Supplement”) to the final prospectus dated June 15, 2009 (as supplemented by the Prospectus Supplement, the “Prospectus”), which forms a part of the Registration Statement, relating to, inter alia , the Company’s offering of 7¼% Series E Cumulative Redeemable Preferred Shares of beneficial interest in the Company; (iii) the Company’s Annual Report on Form 10-K for its year ended December 31, 2010 (the “Form 10-K”); and (iv) the Company’s Quarterly Report on Form 10-Q for its quarterly period ended March 31, 2011 (the “Form 10-Q”).

The opinion set forth below is based upon the Internal Revenue Code of 1986, as amended, the Treasury Regulations issued thereunder, published administrative interpretations thereof, and judicial decisions with respect thereto, all as of the date hereof (collectively, “Tax Laws”), and upon the Employee Retirement Income Security Act of 1974, as amended, the Department of Labor regulations issued thereunder, published administrative interpretations thereof, and judicial decisions with respect thereto, all as of the date hereof (collectively, “ERISA Laws”). No assurance can be given that Tax Laws or ERISA Laws will not change. In preparing the discussions with respect to Tax Laws matters and ERISA Laws matters in the sections of Item 1 of the Form 10-K captioned “Federal Income Tax Considerations” and “ERISA Plans, Keogh Plans and Individual Retirement Accounts”, as supplemented by the section of the Prospectus Supplement captioned “Federal Income Tax and ERISA Considerations”, we have made certain assumptions therein and expressed certain conditions and qualifications therein, all of which assumptions, conditions and qualifications are incorporated herein by reference. With respect to all questions of fact on which our opinion is based, we have assumed the initial and continuing truth, accuracy and completeness of: (i) the information set forth in the Form 10-K, the Form 10-Q, the Prospectus, and the exhibits thereto and the documents incorporated therein by reference; and (ii) representations made to us by officers of the Company or contained in the Form 10-K, the Form 10-Q, the Prospectus, and the exhibits thereto and the documents incorporated therein by reference, in each such instance without regard to qualifications such as “to the best knowledge of” or “in the belief of”. We have not independently verified such information.

We have relied upon, but not independently verified, the foregoing assumptions. If any of the foregoing assumptions are inaccurate or incomplete for any reason, or if the transactions described in the Form 10-K, the Form 10-Q, the Prospectus, or the exhibits thereto or the documents incorporated therein by reference have been consummated in a manner that is inconsistent with the manner contemplated therein, our opinion as expressed below may be adversely affected and may not be relied upon.

Based upon and subject to the foregoing, we are of the opinion that the discussions with respect to Tax Laws matters and ERISA Laws matters in the sections of Item 1 of the Form 10-K captioned “Federal Income Tax Considerations” and “ERISA Plans, Keogh Plans and Individual Retirement Accounts”, as supplemented by the discussion in the section of the Prospectus Supplement captioned “Federal Income Tax and ERISA Considerations”, in all material respects are accurate and fairly summarize the Tax Laws issues and the ERISA Laws issues addressed therein, and hereby confirm that the opinions of counsel referred to in said sections represent our opinions on the subject matter thereof.

Our opinion above is limited to the matters specifically covered hereby, and we have not been asked to address, nor have we addressed, any other matters or any other transactions.

Further, we disclaim any undertaking to advise you of any subsequent changes of the matters stated, represented or assumed herein or any subsequent changes in Tax Laws or ERISA Laws.

This opinion is intended solely for the benefit and use of the Company, and is not to be used, released, quoted, or relied upon by anyone else for any purpose (other than as required by law) without our prior written consent. We hereby consent to the filing of a copy of this opinion as an exhibit to the Form 8-K, which is incorporated by reference in the Company’s Registration Statement, and to the references to our firm in the Prospectus Supplement and such Registration Statement. In giving such consent, we do not thereby admit that we come within the category of persons whose consent is required under Section 7 of the Securities Act or under the rules and regulations of the SEC promulgated thereunder.

	Very truly yours,

	/s/ Sullivan & Worcester LLP

	SULLIVAN & WORCESTER LLP