XOMA LTD /DE/ (Form: S-8, Received: 06/06/2011 16:31:43)

As filed with the Securities and Exchange Commission on June 6, 2011

Registration No. 333-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

____________________

(Exact name of registrant as specified in its charter)

Bermuda	52-2154066
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)

2910 Seventh Street Berkeley, California	94710
(Address of Principal Executive Offices)	(Zip Code)

____________________

XOMA LTD. 2010 LONG TERM INCENTIVE AND SHARE AWARD PLAN

XOMA LTD. 1998 EMPLOYEE SHARE PURCHASE PLAN

(Full title of the plan)

Christopher J. Margolin, Esq.

Berkeley, California 94710

(Name and address of agent for service)

(Telephone number, including area code, of agent for service)

Geoffrey E. Liebmann, Esq.

Cahill Gordon & Reindel LLP

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer	o	Accelerated filer	x
Non-accelerated filer	o (Do not check if a smaller reporting company)	Smaller reporting company	o

CALCULATION OF REGISTRATION FEE

Title of Securities to be Registered	Amount to be Registered (1)	Proposed Maximum Offering Price Per Share (2)	Proposed Maximum Aggregate Offering Price (2)	Amount of Registration Fee (2)
Common Shares, par value US$.0075 per share (2010 Long Term Incentive and Share Award Plan)	5,500,000 shares	$3.01	$16,555,000	$1,922.04
Common Shares, par value US$.0075 per share (1998 Employee Share Purchase Plan)	100,000 shares	$3.01	$301,000	$34.95
Total:	5,600,000 shares	——	$16,856,000	$1,956.99

(1)	Subject to adjustment to prevent dilution resulting from share subdivisions, bonus issues or similar transactions.

(2)

Estimated solely for purposes of calculating the registration fee. Pursuant to Rules 457(c) and 457(h) under the Securities Act of 1933, as amended, the registration fee has been calculated based on the average of the high and low sale prices reported for the Common Shares of XOMA Ltd. on June 1, 2011, which was US$3.01 per share, as reported on The Nasdaq Stock Market.

This Registration Statement on Form S-8 registers additional securities of the same class as other securities for which registration statements filed on Form S-8 relating to the XOMA Ltd. 2010 Long Term Incentive and Share Award Plan and XOMA Ltd. 1998 Employee Share Purchase Plan are effective. Accordingly, pursuant to General Instruction E of Form S-8, the Registration Statements on Form S-8 (File Nos. 333-66171, 333-108306 and 333-171429) filed with the Securities and Exchange Commission on October 27, 1998, August 28, 2003 and December 27, 2010, respectively, are incorporated herein by reference.

All of the common shares of XOMA Ltd. registered hereby for issuance in connection with the 2010 Long Term Incentive and Share Award Plan and the 1998 Employee Share Purchase Plan have been previously approved for issuance pursuant to such plans by the shareholders of XOMA Ltd. at its 2011 Annual General Meeting held on May 26, 2011. This Form S-8 does not reflect any increase in the number of shares issuable pursuant to any of these plans above the numbers previously approved and disclosed.

INFORMATION REQUIRED

IN SECTION 10(a) PROSPECTUS

ITEM 1.

PLAN INFORMATION.*

ITEM 2.

REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION.*

As permitted by Rule 428 under the Securities Act of 1933, as amended (the “Securities Act”), this Registration Statement omits the information specified in Part I of Form S-8. The documents containing the information specified in Part I will be delivered to the participants in the plans covered by this Registration Statement as required by Rule 428(b). Such documents are not being filed with the Securities and Exchange Commission (the “Commission”) as part of this Registration Statement or as prospectuses or prospectus supplements pursuant to Rule 424(b) under the Securities Act.

INFORMATION REQUIRED

IN THE REGISTRATION STATEMENT

ITEM 3.

INCORPORATION OF DOCUMENTS BY REFERENCE.

The following documents have been filed by XOMA Ltd. (“XOMA” or the “Company”) with the Commission pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and are hereby incorporated by reference:

(1)	annual report on Form 10-K for the year ended December 31, 2010, and the amendment to annual report on Form 10-K/A for the year ended December 31, 2010 filed on May 26, 2011 (file no. 0-14710);

(2)	quarterly report on Form 10-Q for the quarterly period ended March 31, 2011 (file no. 0-14710);

(3)	current reports on Form 8-K filed on January 4, 2011, January 7, 2011, January 11, 2011, February 25, 2011, March 1, 2011, March 23, 2011 and June 1, 2011; and

(4)	the description of share capital in the registration statement on Form 8-A filed April 1, 2003 under Section 12 of the Exchange Act, including any amendment or report for the purpose of updating such description (file no. 0-14710).

All documents filed by XOMA with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act, prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities remaining unsold, shall be deemed to be incorporated by reference herein and to be a part hereof from the date any such document is filed.

Any statements contained in a document incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained in this Registration Statement or in any other subsequently filed document which also is incorporated by reference herein

modifies or supersedes such statement. Any statement so modified or superseded shall not be deemed to constitute a part of this Registration Statement except as so modified or superseded.

ITEM 4.

DESCRIPTION OF SECURITIES.

The description of the registrant's Common Shares to be offered pursuant to this Registration Statement has been incorporated by reference into this Registration Statement as described in Item 3 of this Part II.

ITEM 5.

INTERESTS OF NAMED EXPERTS AND COUNSEL.

ITEM 6.

INDEMNIFICATION OF DIRECTORS AND OFFICERS.

Under Bermuda law, a company is permitted to indemnify any officer or director, out of the funds of the company, against (i) any liability incurred by him or her in defending any proceedings, whether civil or criminal, in which judgment is given in his or her favor, or in which he or she is acquitted, or in connection with any application under relevant Bermuda legislation in which relief from liability is granted to him or her by the court and (ii) any loss or liability resulting from negligence, default, breach of duty or breach of trust, save for his or her fraud or dishonesty.

The bye-laws of XOMA provide for the indemnity by XOMA of the officers, directors and employees of XOMA to the fullest extent permitted by law.

Expenses (including attorneys’ fees) incurred by an officer or director of XOMA in defending any civil, criminal, administrative or investigative action, suit or proceeding shall be paid by XOMA in advance of the final disposition of such action, suit or proceeding upon receipt of an undertaking by or on behalf of such director or officer to repay such amount if it shall ultimately be determined that he is not entitled to be indemnified by XOMA pursuant to the Companies Act 1981 of Bermuda.

An officer or director of XOMA shall not be personally liable to XOMA or its shareholders for monetary damages for any breach of fiduciary duty as a director or officer, except to the extent that such limitation is prohibited by the Companies Act 1981 of Bermuda.

The indemnification and advancement of expenses and the limitation of liability provided by the bye-laws shall not be deemed exclusive of any other rights which any officer, director or employee, as such, may have or hereafter acquire under the Companies Act 1981 of Bermuda, any other provision of the bye-laws, or any agreement or otherwise. Any repeal or modification of the aforementioned provisions of the bye-laws shall not adversely affect any right or protection existing at the time of such repeal or modification.

ITEM 7.

EXEMPTION FROM REGISTRATION CLAIMED.

ITEM 9.

UNDERTAKINGS.

The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in the volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to rule 424(b) if, in the aggregate, the changes and volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement.

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

Provided, however , that paragraphs (1)(i) and (1)(ii) do not apply if the information required to be included in the post-effective amendment by those paragraphs is contained in periodic reports filed by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit's plan's annual report pursuant to section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered herein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Berkeley, State of California, on June 6, 2011.

XOMA LTD.

By: /s/ Steven B. Engle

Name: Steven B. Engle

Title: Chairman of the Board, Chief

Executive Officer and President

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Steven B. Engle and Christopher J. Margolin, and each of them, as his true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) and supplements to this registration statement, and to file the same, with the United States Securities and Exchange Commission and the Bermuda Registrar of Companies, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the date indicated.

Signature	Title	Date
/s/ Steven B. Engle Steven B. Engle	Chairman of the Board, Chief Executive Officer and President (Principal Executive Officer)	June 6, 2011
/s/ Fred Kurland Fred Kurland	Vice President, Finance and Chief Financial Officer (Principal Financial and Accounting Officer)	June 6, 2011
/s/ Patrick J. Scannon Patrick J. Scannon M.D., Ph.D.\	Executive Vice President and Chief Scientific Officer and Director	June 6, 2011
/s/ W. Denman Van Ness W. Denman Van Ness	Lead Independent Director	June 6, 2011
/s/ William K. Bowes, Jr. William K. Bowes, Jr.	Director	June 6, 2011
/s/ Peter Barton Hutt Peter Barton Hutt	Director	June 6, 2011
/s/ John Varian John Varian	Director	June 6, 2011
/s/ Timothy P. Walbert Timothy P. Walbert	Director	June 6, 2011
/s/ Jack L. Wyszomierski Jack L. Wyszomierski	Director	June 6, 2011

Exhibit Number	Exhibit
3.1	Memorandum of Continuance of XOMA Ltd. (Exhibit 3.4) (1)
3.2	Bye-Laws of XOMA Ltd. as amended (Exhibit 3.2) (2)
4.1	Shareholder Rights Agreement dated as of February 26, 2003 by and between XOMA Ltd. and Mellon Investor Services LLC as Rights Agent (Exhibit 4.1) (2)
4.1A	Amendment to Shareholder Rights Agreement dated December 21, 2010 between XOMA Ltd. and Wells Fargo Bank, N.A. as Rights Agent (Exhibit 4.1A) (3)
4.2	Resolution Regarding Preferences and Rights of Series A Preference Shares (Exhibit A to Exhibit 4.1) (2)
4.3	Form of Amended and Restated Warrant (June 2009 Warrants) (Exhibit 10.6) (4)
4.4	Form of Warrant (February 2010 Warrants) (Exhibit 10.2) (4)
5.1	Legal Opinion of Conyers Dill & Pearman Limited*
10.1	2010 Long Term Incentive and Share Award Plan as amended*
10.1A	Form of Share Option Agreement for 2010 Long Term Incentive and Share Award Plan (Exhibit 10.5A) (5)
10.2	1998 Employee Share Purchase Plan as amended and restated*
23.1	Consent of Independent Registered Public Accounting Firm*
23.2	Consent of Conyers Dill & Pearman (included in Exhibit 5.1)
24.1	Power of Attorney (included on signature page to Registration Statement)

____________________

(1)	Incorporated by reference to the referenced exhibit to XOMA’s Registration Statement on Form S-4 filed November 27, 1998, as amended (File No. 333-68045).

(2)	Incorporated by reference to the referenced exhibit to XOMA’s Annual Report on Form 10-K for the fiscal year end December 31, 2002 (File No. 0-14710).

(3)	Incorporated by reference to the referenced exhibit to XOMA’s Annual Report on Form 10-K for the fiscal year end December 31, 2010 (File No. 0-14710).

(4)	Incorporated by reference to the referenced exhibit to XOMA’s Current Report on Form 8-K filed February 2, 2010 (File No. 0-14710).

(5)	Incorporated by reference to the referenced exhibit to XOMA’s Registration Statement on Form S-8 (File No. 333-171429) filed December 27, 2010.

[LETTERHEAD OF CONYERS DILL & PEARMAN]

Re: XOMA Ltd. (the “Company”)

We have acted as special legal counsel in Bermuda to the Company in connection with a draft registration statement on form S-8 to be filed with the United States Securities and Exchange Commission (the “Commission”) on or about 6 June 2011 (the “Registration Statement”, which term does not include any other document or agreement whether or not specifically referred to therein or attached as an exhibit or schedule thereto) relating to the registration under the United States Securities Act of 1933, as amended, (the “Securities Act”) of 5,600,000 common shares, par value US$0.0075 per share of the Company (the “Common Shares”), issuable pursuant to the Company’s 1998 Employee Share Purchase Plan (as amended through 26 May 2011, the "Employee Purchase Plan") and 2010 Long Term Incentive and Share Award Plan (as amended through 26 May 2011) (collectively, the “Plans”, which term does not include any other document or agreement whether or not specifically referred to therein or attached as an exhibit or schedule thereto).

For the purposes of giving this opinion, we have examined copies of the Registration Statement and the Plans. We have also reviewed the memorandum of continuance and the bye-laws of the Company, each certified by the Secretary of the Company on 1 June 2011, copies of minutes of meetings of the members of the Company held on 21 July 2010 and 26 May 2011 and resolutions passed at meetings of the board of directors of the Company held on 25 May 2010 and 24 February 2011 (together, the “Minutes”) and such other documents and made such enquires as to questions of law as we have deemed necessary in order to render the opinion set forth below.

We have assumed (a) the genuineness and authenticity of all signatures and the conformity to the originals of all copies (whether or not certified) of all documents examined by us and the authenticity and completeness of the originals from which such copies were taken, (b) that where a document has been examined by us in draft form, it will be or has been executed and/or filed in the form of that draft, and where a number of drafts of a document have been examined by us all changes thereto have been marked or otherwise drawn to our attention, (c) the accuracy and completeness of all factual representations made in the Registration Statement, the Plans and other documents reviewed by us, (d) that the resolutions contained in the Minutes were passed at one or more duly convened, constituted and quorate meetings, or by unanimous written resolutions, remain in full force and effect and have not been rescinded or amended, (e) that the Minutes contain all resolutions amending or affecting the Plans, (f) that there is no provision of the law of any jurisdiction, other than Bermuda, which would have any implication in relation to the opinions expressed herein, (g) that the Employee Purchase Plan is governed by the laws of the State of California and is valid and binding under such laws in accordance with its terms; (h) that there is no provision of any award agreement or option agreement which would have any implication in relation to the opinions expressed herein; (i) that, upon the issue of any Common Shares, the Company will receive consideration (other than in the form of a promissory note) for the full issue price thereof, which shall be equal to at least the par value thereof, (j) that on the date of issuance of any of the Common Shares the Company will have sufficient authorised but unissued common shares to effect such issuance, (k) that on the date of issuance of any award or option under the Plans and on the date of exercise of any such option, the Company will be able to pay its liabilities as they become due, and (l) that the Company’s shares will be listed on an appointed stock exchange, as defined in the Companies Act 1981, and the consent to the issue and free transfer of Common Shares given by the

Bermuda Monetary Authority dated 8 February 2000 will not have been revoked or amended at the time of issuance of any Common Shares.

“Non-assessability” is not a legal concept under Bermuda law, but when we describe the Common Shares herein as being “non-assessable” we mean, subject to any contrary provision in any agreement between the Company and any one of its members holding any of the Common Shares (but only with respect to such member), that no further sums are payable with respect to the issue of such shares and no member shall be bound by an alteration in the Company’s memorandum of continuance or bye-laws after the date upon which it became a member if and so far as the alteration requires such member to take or subscribe for additional Common Shares or in any way increases its liability to contribute to the share capital of, or otherwise pay money to, the Company.

We have made no investigation of and express no opinion in relation to the laws of any jurisdiction other than Bermuda. This opinion is to be governed by and construed in accordance with the laws of Bermuda and is limited to and is given on the basis of the current law and practice in Bermuda. This opinion is issued solely for the purposes of the filing of the Registration Statement and the issuance of the Common Shares by the Company pursuant to the Plans and is not to be relied upon in respect of any other matter.

On the basis of, and subject to, the foregoing, we are of the opinion that, when issued and paid for in accordance with the terms of the Plans, the Common Shares will be validly issued, fully paid and non-assessable.

We consent to the filing of this opinion as an exhibit to the Registration Statement. In giving such consent, we do not hereby admit that we are experts within the meaning of Section 11 of the Securities Act or that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the Rules and Regulations of the Commission promulgated thereunder.

Conyers Dill & Pearman Limited

Exhibit 10.1

XOMA LTD.

2010 LONG TERM INCENTIVE AND SHARE AWARD PLAN

(as amended through May 26, 2011)

1. Purposes .

The purposes of the XOMA Ltd. 2010 Long Term Incentive and Share Award Plan are to advance the interests of XOMA Ltd. and its shareholders by providing a means to attract, retain, and motivate employees, consultants and directors of the Company, its Subsidiaries and Affiliates, to provide for competitive compensation opportunities, to encourage long term service, to recognize individual contributions and reward achievement of performance goals, and to promote the creation of long term value for shareholders by aligning the interests of such persons with those of shareholders.

2. Definitions .

For purposes of this Plan, the following terms shall be defined as set forth below:

(a) “Affiliate” means any entity other than the Company and its Subsidiaries that is designated by the Board or the Committee as a participating employer under this Plan; provided , however , that the Company directly or indirectly owns at least 20% of the combined voting power of all classes of stock of such entity or at least 20% of the ownership interests in such entity.

(b) “Award” means any Option, SAR, Restricted Share, Restricted Share Unit, Performance Share, Performance Unit, Dividend Equivalent, or Other Share-Based Award granted to an Eligible Person under this Plan.

(d) “Beneficiary” means the person, persons, trust or trusts which have been designated by an Eligible Person in his or her most recent written beneficiary designation filed with the Company to receive the benefits specified under this Plan upon the death of the Eligible Person, or, if there is no designated Beneficiary or surviving designated Beneficiary, then the person, persons, trust or trusts entitled by will or the laws of descent and distribution to receive such benefits.

(e) “Board” means the Board of Directors of the Company.

(f) “Change in Control” means the occurrence of any of the following events:

(i) a merger, amalgamation or acquisition in which the Company is not the surviving or continuing entity, except for a transaction the principal purpose of which is to change the jurisdiction of the Company’s organization;

(ii) the sale, transfer or other disposition of all or substantially all of the assets of the Company;

(iii) any other reorganization or business combination in which fifty percent (50%) or more of the Company’s outstanding voting securities are transferred to different holders in a single transaction or series of related transactions;

(iv) any approval by the shareholders of the Company of a plan of complete liquidation of the Company;

(v) any “person” (as such term is used in Sections 13(d) and 14(d) of the Exchange Act) becoming the “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of securities of the Company representing more than fifty percent (50%) of the total voting power represented by the Company’s then outstanding voting securities; or

(vi) a change in the composition of the Board, as a result of which fewer than a majority of the directors are Incumbent Directors.

(g) “Code” means the Internal Revenue Code of 1986, as amended from time to time. References to any provision of the Code shall be deemed to include successor provisions thereto and regulations thereunder.

(h) “Committee” means the Compensation Committee of the Board, or such other Board committee or committees (which may include the entire Board) as may be designated by the Board to administer all or any portion of this Plan; provided , however , that, unless otherwise determined by the Board, a Committee shall consist of two or more directors of the Company, each of whom is a “non-employee director” within the meaning of Rule 16b-3 under the Exchange Act, to the extent applicable, and each of whom is an “outside director” within the meaning of Section 162(m) of the Code, to the extent applicable; provided , further , that the mere fact that a Committee shall fail to qualify under either of the foregoing requirements shall not invalidate any Award made by such Committee which Award is otherwise validly made under this Plan. Different Committees may administer this Plan with respect to different groups of Eligible Persons. As used herein, the singular “Committee” shall include the plural “Committees” if applicable, except where the context requires otherwise.

(i) “Company” means XOMA Ltd., a company organized under the laws of Bermuda, or any successor company.

(j) “Director” means a member of the Board who is not an employee of the Company, a Subsidiary or an Affiliate.

(k) “Dividend Equivalent” means a right, granted under Section 5(g), to receive cash, Shares, or other property equal in value to dividends paid with respect to a specified number of Shares. Dividend Equivalents may be awarded on a free-standing basis or in connection with another Award, and may be paid currently or on a deferred basis.

(l) “Effective Date” means July 21, 2010, contingent on shareholder approval of this Plan on such date.

(m) “Eligible Person” means (i) an employee or consultant of the Company, a Subsidiary or an Affiliate, including any director who is an employee, or (ii) a Director. Notwithstanding any provisions of this Plan to the contrary, an Award may be granted to an employee or consultant in connection with his or her hiring or retention prior to the date the employee or consultant first performs services for the Company, a Subsidiary or an Affiliate; provided , however , that any such Award shall not become vested or exercisable prior to the date the employee or consultant first performs such services.

(n) “Exchange Act” means the Securities Exchange Act of 1934, as amended from time to time. References to any provision of the Exchange Act shall be deemed to include successor provisions thereto and regulations thereunder.

(o) “Fair Market Value” means:

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(i) if the Shares are not at the time listed or admitted to trading on any stock exchange but are traded in the over-the-counter market, the fair market value shall be the closing selling price per Share on the date in question, as such price is reported by the National Association of Securities Dealers through its Nasdaq National Market or any successor system; provided that if there is no reported closing selling price for Shares on the date in question, then the closing selling price on the last preceding date for which such quotation exists shall be determinative of fair market value;

(ii) if the Shares are at the time listed or admitted to trading on any stock exchange, then the fair market value shall be the closing selling price per Share on the date in question on the stock exchange determined by the Committee to be the primary market for the Shares, as such price is officially quoted on such exchange; provided that if there is no reported sale of Shares on such exchange on the date in question, then the fair market value shall be the closing selling price on the exchange on the last preceding date for which such quotation exists; or

(iii) if the Shares are at the time neither listed nor admitted to trading on any stock exchange nor traded in the over-the-counter market (or if the Committee determines that the value as determined pursuant to subsection (i) or (ii) above does not reflect fair market value), then the Committee shall determine fair market value after taking into account such factors as it deems appropriate, including one or more independent professional appraisals.

(p) “Incumbent Directors” means directors who (i) are directors of the Company as of the date hereof, (ii) are elected, or nominated for election, to the Board with the affirmative votes of the directors of the Company as of the date hereof, or (iii) are elected, or nominated for election, to the Board with the affirmative votes of at least a majority of those directors whose election or nomination was not in connection with any transaction described in subsections (i) through (v) of the definition of Change in Control or in connection with an actual or threatened proxy contest relating to the election of directors of the Company.

(q) “ISO” means any Option intended to be and designated as an incentive stock option within the meaning of Section 422 of the Code.

(r) “NQSO” means any Option that is not an ISO.

(s) “Option” means a right, granted under Section 5(b), to purchase Shares.

(t) “Other Share-Based Award” means a right, granted under Section 5(h), that relates to or is valued by reference to Shares.

(u) “Participant” means an Eligible Person who has been granted an Award under this Plan.

(v) “Performance Award” shall have the meaning set forth in Section 7(a).

(w) “Performance Period” shall have the meaning set forth in Section 5(f)(i).

(x) “Performance Share” means a performance share granted under Section 5(f).

(y) “Performance Unit” means a performance unit granted under Section 5(f).

(z) “Plan” means this XOMA Ltd. 2010 Long Term Incentive and Share Award Plan.

(aa) “Restricted Shares” means an Award of Shares under Section 5(d) that may be subject to certain restrictions and to a risk of forfeiture.

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(bb) “Restricted Share Unit” means a right, granted under Section 5(e), to receive Shares or cash at the end of a specified deferral period.

(cc) “Rule 16b-3” means Rule 16b-3, as from time to time in effect and applicable to this Plan and Participants, promulgated by the Securities and Exchange Commission under Section 16 of the Exchange Act.

(dd) “SAR” or “Share Appreciation Right” means the right, granted under Section 5(c), to be paid an amount measured by the difference between the exercise price of the right and the Fair Market Value of Shares on the date of exercise of the right, with payment to be made in cash, Shares, or property as specified in the Award or determined by the Committee.

(ee) “Shares” means common shares of the Company, and such other securities as may be substituted for Shares pursuant to Section 4(c) hereof.

(ff) “Subsidiary” means any company (other than the Company) in an unbroken chain of companies beginning with the Company if each of the companies (other than the last company in the unbroken chain) owns shares possessing 50% or more of the total combined voting power of all classes of stock in one of the other companies in the chain.

(gg) “Termination of Service” means the termination of the Participant’s employment, consulting services or directorship with the Company, its Subsidiaries and its Affiliates, as the case may be. A Participant employed by a Subsidiary of the Company or one of its Affiliates shall also be deemed to incur a Termination of Service if the Subsidiary of the Company or Affiliate ceases to be such a Subsidiary or an Affiliate, as the case may be, and the Participant does not immediately thereafter become an employee or director of, or a consultant to, the Company, another Subsidiary of the Company or an Affiliate. In the event that a Participant who is an employee of the Company, a Subsidiary or an Affiliate becomes a Director or a consultant to the Company, a Subsidiary or an Affiliate upon the Participant’s termination of employment, unless otherwise determined by the Committee in its sole discretion, no Termination of Service shall be deemed to occur until such time as such Participant is no longer an employee of, or consultant to, the Company, a Subsidiary or an Affiliate or a Director, as the case may be. If a Participant who is a Director becomes an employee of, or a consultant to, the Company, a Subsidiary or an Affiliate upon such Participant ceasing to be a Director, unless otherwise determined by the Committee in its sole discretion, such termination of the Participant’s directorship shall not be treated as a Termination of Service unless and until the Participant’s employment or consultancy, as the case may be, terminates. Temporary absences from employment because of illness, vacation or leave of absence and transfers among the Company and its Subsidiaries and Affiliates shall not be considered a Termination of Service.

3. Administration .

(a) Authority of the Committee . This Plan shall be administered by the Committee, and the Committee shall have full and final authority to take the following actions, in each case subject to and consistent with the provisions of this Plan:

(i) to select Eligible Persons to whom Awards may be granted;

(ii) to designate Affiliates;

(iii) to determine the type or types of Awards to be granted to each Eligible Person;

(iv) to determine the type and number of Awards to be granted, the number of Shares to which an Award may relate, the terms and conditions of any Award granted under this Plan

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(including, but not limited to, any exercise price, grant price, or purchase price, any restriction or condition, any schedule for lapse of restrictions or conditions relating to transferability or forfeiture, exercisability, or settlement of an Award, and waiver or accelerations thereof, and waivers of performance conditions relating to an Award, based in each case on such considerations as the Committee shall determine), and all other matters to be determined in connection with an Award;

(v) to determine whether, to what extent, and under what circumstances an Award may be settled, or the exercise price of an Award may be paid, in cash, Shares, other Awards, or other property, or an Award may be canceled, forfeited (including by repurchase at a nominal price, where required by Bermuda law), exchanged, or surrendered;

(vi) to determine whether, to what extent, and under what circumstances cash, Shares, other Awards, or other property payable with respect to an Award will be deferred either automatically, at the election of the Committee, or at the election of the Eligible Person, provided that such deferral shall be intended to be in compliance with Section 409A of the Code;

(vii) to prescribe the form of each Award Agreement, which need not be identical for each Eligible Person;

(viii) to adopt, amend, suspend, waive, and rescind such rules and regulations and appoint such agents as the Committee may deem necessary or advisable to administer this Plan;

(ix) to correct any defect or supply any omission or reconcile any inconsistency in this Plan and to construe and interpret this Plan and any Award, rules and regulations, Award Agreement, or other instrument hereunder;

(x) to accelerate the exercisability or vesting of all or any portion of any Award or to extend the period during which an Award is exercisable;

(xi) to determine whether uncertificated Shares may be used in satisfying Awards and otherwise in connection with this Plan; and

(xii) to make all other decisions and determinations as may be required under the terms of this Plan or as the Committee may deem necessary or advisable for the administration of this Plan.

(b) Manner of Exercise of Committee Authority . The Committee shall have sole discretion in exercising its authority under this Plan. Any action of the Committee with respect to this Plan shall be final, conclusive, and binding on all persons, including the Company, Subsidiaries, Affiliates, Eligible Persons, any person claiming any rights under this Plan from or through any Eligible Person, and shareholders. The express grant of any specific power to the Committee, and the taking of any action by the Committee, shall not be construed as limiting any power or authority of the Committee. The Committee may delegate to other members of the Board or officers or managers of the Company or any Subsidiary or Affiliate the authority, subject to such terms as the Committee shall determine, to perform administrative functions and, with respect to Awards granted to persons not subject to Section 16 of the Exchange Act, to perform such other functions as the Committee may determine, to the extent permitted under Rule 16b-3 (if applicable) and applicable law.

(c) Limitation of Liability . Each member of the Committee shall be entitled to, in good faith, rely or act upon any report or other information furnished to him or her by any officer or other employee of the Company or any Subsidiary or Affiliate, the Company’s independent certified public accountants, or other professional retained by the Company to assist in the administration of this Plan. No member of the Committee, and no officer or employee of the Company acting on behalf of the Committee, shall be personally liable for any action, determination, or interpretation taken or made in good faith with respect to this Plan, and all members of

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the Committee and any officer or employee of the Company acting on their behalf shall, to the extent permitted by law, be fully indemnified and protected by the Company with respect to any such action, determination, or interpretation.

(d) Limitation on Committee’s Discretion . Anything in this Plan to the contrary notwithstanding, in the case of any Award which is intended to qualify as “performance-based compensation” within the meaning of Section 162(m)(4)(C) of the Code, the Committee shall have no discretion to increase the amount of compensation payable under the Award to the extent such an increase would cause the Award to lose its qualification as such performance-based compensation.

(e) No Option or SAR Repricing Without Shareholder Approval . Except as provided in the first sentence of Section 4(c) hereof relating to certain anti-dilution adjustments, unless the approval of shareholders of the Company is obtained, (i) Options and SARs shall not be amended to lower their exercise price, (ii) Options and SARs will not be exchanged for other Options or SARs with lower exercise prices, (iii) Options and SARs with an exercise price in excess of the Fair Market Value of the underlying Shares will not be exchanged for cash or other property and (iii) no other action shall be taken with respect to Options or SARs that would be treated as a repricing under the rules of the principal stock exchange on which the Shares are listed.

(f) Limitation on Committee’s Authority under 409A . Anything in this Plan to the contrary notwithstanding, the Committee’s authority to modify outstanding Awards shall be limited to the extent necessary so that the existence of such authority does not (i) cause an Award that is not otherwise deferred compensation subject to Section 409A of the Code to become deferred compensation subject to Section 409A of the Code or (ii) cause an Award that is otherwise deferred compensation subject to Section 409A of the Code to fail to meet the requirements prescribed by Section 409A of the Code.

4. Shares Subject to this Plan .

(a) Subject to adjustment as provided in Section 4(c) hereof, the total number of Shares reserved for issuance in connection with Awards under this Plan shall be (i) 6,150,718 plus (ii) the number of Shares subject to awards granted prior to the Effective Date of this Plan under the Company’s 1981 Share Option Plan, its Restricted Share Plan or its 1992 Directors Share Option Plan which awards are, after the Effective Date, forfeited, canceled, surrendered or otherwise terminated without a distribution of Shares to the holder of the award; provided , however , that, subject to adjustment as provided in Section 4(c) hereof, no more than 2,000,000 Shares may be issued as ISOs under this Plan; and, provided , further , that, in the case of Awards granted out of the 5,500,000 Share allotment added to such total number of available Shares with the approval of the Company’s shareholders effective May 26, 2011, for each SAR, Restricted Share, Restricted Share Unit, Performance Share, Performance Unit, Dividend Equivalent or Other Share-Based Award issued, such total number of available Shares shall be reduced by 1.3 Shares. No Award may be granted if the number of Shares to which such Award relates, when added to the number of Shares previously issued under this Plan, exceeds the number of Shares reserved under the applicable provisions of the preceding sentence. If any Awards are forfeited (including by repurchase at a nominal price, where required by Bermuda law), canceled, terminated, exchanged or surrendered or such Award is settled in cash or otherwise terminates without a distribution of Shares to the Participant, any Shares counted against the number of Shares reserved and available under this Plan with respect to such Award shall, to the extent of any such forfeiture, repurchase, settlement, termination, cancellation, exchange or surrender, again be available for Awards under this Plan. Upon the exercise of any Award granted in tandem with any other Awards, such related Awards shall be canceled to the extent of the number of Shares as to which the Award is exercised.

(b) Subject to adjustment as provided in Section 4(c) hereof, the maximum number of Shares (i) with respect to which Options or SARs may be granted during a calendar year to any Eligible Person under this Plan shall be 466,666 Shares, and (ii) with respect to which Performance Shares, Performance Units, Restricted Shares or Restricted Share Units intended to qualify as performance-based compensation within the

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meaning of Section 162(m)(4)(C) of the Code may be granted during a calendar year to any Eligible Person under this Plan shall be 466,666 Shares.

(c) In the event that the Committee shall determine that any dividend in Shares, recapitalization, Share split, reverse split, reorganization, merger, consolidation, spin-off, combination, repurchase, share exchange, extraordinary distribution or other similar corporate transaction or event, affects the Shares such that an adjustment is appropriate in order to prevent dilution or enlargement of the rights of Eligible Persons under this Plan, then the Committee shall make such equitable changes or adjustments as it deems appropriate and, in such manner as it may deem equitable, (i) adjust any or all of (x) the number and kind of shares which may thereafter be issued under this Plan, (y) the number and kind of shares, other securities or other consideration issued or issuable in respect of outstanding Awards, and (z) the exercise price, grant price, or purchase price relating to any Award, or (ii) provide for a distribution of cash or property in respect of any Award; provided , however , in each case that, with respect to ISOs, such adjustment shall be made in accordance with Section 424(a) of the Code, unless the Committee determines otherwise; provided , further , that no adjustment shall be made pursuant to this Section 4(c) that causes any Award that is not otherwise deferred compensation subject to Section 409A of the Code to be treated as deferred compensation pursuant to Section 409A of the Code. In addition, the Committee is authorized to make adjustments in the terms and conditions of, and the criteria and performance objectives, if any, included in, Awards in recognition of unusual or non-recurring events (including, without limitation, events described in the preceding sentence) affecting the Company or any Subsidiary or Affiliate or the financial statements of the Company or any Subsidiary or Affiliate, or in response to changes in applicable laws, regulations, or accounting principles; provided , however , that the Committee shall not have discretion to increase the amount of compensation payable under any Award intended to qualify as performance-based compensation for purposes of Section 162(m)(4)(C) of the Code to the extent such an increase would cause the Award to lose its qualification as performance-based compensation for purposes of Section 162(m)(4)(C) of the Code and the regulations thereunder.

(d) Any Shares distributed pursuant to an Award may consist, in whole or in part, of authorized and unissued Shares or treasury Shares including Shares acquired by purchase in the open market or in private transactions.

5. Specific Terms of Awards .

(a) General . Awards may be granted on the terms and conditions set forth in this Section 5. In addition, the Committee may impose on any Award or the exercise thereof, at the date of grant or thereafter (subject to Section 9(d)), such additional terms and conditions, not inconsistent with the provisions of this Plan, as the Committee shall determine, including terms regarding forfeiture (including by repurchase at a nominal price, where required by Bermuda law) of Awards or continued exercisability of Awards in the event of Termination of Service by the Eligible Person.

(b) Options . The Committee is authorized to grant Options, which may be NQSOs or ISOs, to Eligible Persons on the following terms and conditions:

(i) Exercise Price . The exercise price per Share purchasable under an Option shall be determined by the Committee; provided , however , that the exercise price per Share of an Option shall not be less than the Fair Market Value of a Share on the date of grant of the Option. The Committee may, without limitation, set an exercise price that is based upon achievement of performance criteria if deemed appropriate by the Committee.

(ii) Option Term . The term of each Option shall be determined by the Committee; provided , however , that such term shall not be longer than ten years from the date of grant of the Option.

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(iii) Time and Method of Exercise . The Committee shall determine at the date of grant or thereafter the time or times at which an Option may be exercised in whole or in part (including, without limitation, upon achievement of performance criteria if deemed appropriate by the Committee), the methods by which such exercise price may be paid or deemed to be paid (including, without limitation, broker-assisted exercise arrangements), the form of such payment (including, without limitation, cash, Shares or other property), and the methods by which Shares will be delivered or deemed to be delivered to Eligible Persons.

(iv) ISOs . The terms of any ISO granted under this Plan shall comply in all respects with the provisions of Section 422 of the Code, including but not limited to the requirement that the ISO shall be granted within ten years from the earlier of the date of adoption or shareholder approval of this Plan. ISOs may only be granted to employees of the Company or a Subsidiary.

(c) SARs . The Committee is authorized to grant SARs (Share Appreciation Rights) to Eligible Persons on the following terms and conditions:

(i) Right to Payment . A SAR shall confer on the Eligible Person to whom it is granted a right to receive with respect to each Share subject thereto, upon exercise thereof, the excess of (1) the Fair Market Value of one Share on the date of exercise over (2) the exercise price per Share of the SAR, as determined by the Committee as of the date of grant of the SAR (which shall not be less than the Fair Market Value per Share on the date of grant of the SAR and, in the case of a SAR granted in tandem with an Option, shall be equal to the exercise price of the underlying Option).

(ii) Other Terms . The Committee shall determine, at the time of grant or thereafter, the time or times at which a SAR may be exercised in whole or in part (which shall not be more than ten years after the date of grant of the SAR), the method of exercise, method of settlement, form of consideration payable in settlement, method by which Shares will be delivered or deemed to be delivered to Eligible Persons, whether or not a SAR shall be in tandem with any other Award, and any other terms and conditions of any SAR. Unless the Committee determines otherwise, a SAR (1) granted in tandem with an NQSO may be granted at the time of grant of the related NQSO or at any time thereafter and (2) granted in tandem with an ISO may only be granted at the time of grant of the related ISO.

(d) Restricted Shares . The Committee is authorized to grant Restricted Shares to Eligible Persons on the following terms and conditions:

(i) Issuance and Restrictions . Restricted Shares shall be subject to such restrictions on transferability and other restrictions, if any, as the Committee may impose at the date of grant or thereafter, which restrictions may lapse separately or in combination at such times, under such circumstances (including, without limitation, upon achievement of performance criteria if deemed appropriate by the Committee), in such installments, or otherwise, as the Committee may determine. Except to the extent restricted under the Award Agreement relating to the Restricted Shares, an Eligible Person granted Restricted Shares shall have all of the rights of a shareholder including, without limitation, the right to vote Restricted Shares and the right to receive dividends thereon.

(ii) Forfeiture . Except as otherwise determined by the Committee, at the date of grant or thereafter, upon Termination of Service during the applicable restriction period, Restricted Shares shall be repurchased by the Company for a nominal amount equal to their par value and any accrued but unpaid dividends or Dividend Equivalents that are at that time subject to restrictions shall be forfeited; provided , however , that the Committee may provide, by rule or regulation or in any Award Agreement, or may determine in any individual case, that restrictions or forfeiture conditions relating to Restricted Shares will be waived in whole or in part in the event of Termination of Service resulting from specified causes, and the Committee may in other cases waive in whole or in part the forfeiture of Restricted Shares.

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(iii) Certificates for Shares . Restricted Shares granted under this Plan may be evidenced in such manner as the Committee shall determine. If certificates representing Restricted Shares are registered in the name of the Eligible Person, such certificates shall bear an appropriate legend referring to the terms, conditions, and restrictions applicable to such Restricted Shares, and, unless otherwise determined by the Committee, the Company shall retain physical possession of the certificate and the Participant shall deliver a stock power to the Company, endorsed in blank, relating to the Restricted Shares.

(iv) Dividends . Dividends paid on Restricted Shares shall be either paid at the dividend payment date, or deferred for payment to such date, and subject to such conditions, as determined by the Committee, in cash or in restricted or unrestricted Shares having a Fair Market Value equal to the amount of such dividends. Unless otherwise determined by the Committee, Shares distributed in connection with a Share split or dividend in Shares, and other property distributed as a dividend, shall be subject to restrictions and a risk of forfeiture to the same extent as the Restricted Shares with respect to which such Shares or other property has been distributed.

(e) Restricted Share Units . The Committee is authorized to grant Restricted Share Units to Eligible Persons, subject to the following terms and conditions:

(i) Award and Restrictions . Delivery of Shares or cash, as the case may be, will occur upon expiration of the deferral period specified for Restricted Share Units by the Committee (or, if permitted by the Committee, as elected by the Eligible Person). In addition, Restricted Share Units shall be subject to such restrictions as the Committee may impose, if any (including, without limitation, the achievement of performance criteria if deemed appropriate by the Committee), at the date of grant or thereafter, which restrictions may lapse at the expiration of the deferral period or at earlier or later specified times, separately or in combination, in installments or otherwise, as the Committee may determine.

(ii) Forfeiture . Except as otherwise determined by the Committee at the date of grant or thereafter, upon Termination of Service during the applicable deferral period or portion thereof to which forfeiture conditions apply (as provided in the Award Agreement evidencing the Restricted Share Units), or upon failure to satisfy any other conditions precedent to the delivery of Shares or cash to which such Restricted Share Units relate, all Restricted Share Units that are at that time subject to deferral or restriction shall be forfeited; provided , however , that the Committee may provide, by rule or regulation or in any Award Agreement, or may determine in any individual case, that restrictions or forfeiture conditions relating to Restricted Share Units will be waived in whole or in part in the event of Termination of Service resulting from specified causes, and the Committee may in other cases waive in whole or in part the forfeiture of Restricted Share Units.

(iii) Dividend Equivalents . Unless otherwise determined by the Committee at the date of grant, Dividend Equivalents on the specified number of Shares covered by a Restricted Share Unit shall be either (A) paid with respect to such Restricted Share Unit at the dividend payment date in cash or in restricted or unrestricted Shares having a Fair Market Value equal to the amount of such dividends, or (B) deferred with respect to such Restricted Share Unit and the amount or value thereof automatically deemed reinvested in additional Restricted Share Units or other Awards, as the Committee shall determine.

(f) Performance Shares and Performance Units . The Committee is authorized to grant Performance Shares or Performance Units or both to Eligible Persons on the following terms and conditions:

(i) Performance Period . The Committee shall determine a performance period (the “Performance Period”) of one or more years or other periods and shall determine the performance objectives for grants of Performance Shares and Performance Units. Performance objectives may vary

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from Eligible Person to Eligible Person and shall be based upon the performance criteria as the Committee may deem appropriate. The performance objectives may be determined by reference to the performance of the Company, or of a Subsidiary or Affiliate, or of a division or unit of any of the foregoing. Performance Periods may overlap and Eligible Persons may participate simultaneously with respect to Performance Shares and Performance Units for which different Performance Periods are prescribed.

(ii) Award Value . At the beginning of a Performance Period, the Committee shall determine for each Eligible Person or group of Eligible Persons with respect to that Performance Period the range of number of Shares, if any, in the case of Performance Shares, and the range of dollar values, if any, in the case of Performance Units, which may be fixed or may vary in accordance with such performance or other criteria specified by the Committee, which shall be paid to an Eligible Person as an Award if the relevant measure of Company performance for the Performance Period is met.

(iii) Significant Events . If during the course of a Performance Period there shall occur significant events as determined by the Committee which the Committee expects to have a substantial effect on a performance objective during such period, the Committee may revise such objective; provided , however , that, in the case of any Award intended to qualify as performance-based compensation for purposes of Section 162(m)(4)(C) of the Code, the Committee shall not have any discretion to increase the amount of compensation payable under the Award to the extent such an increase would cause the Award to lose its qualification as performance-based compensation for purposes of Section 162(m)(4)(C) of the Code and the regulations thereunder.

(iv) Forfeiture . Except as otherwise determined by the Committee at the date of grant or thereafter, upon Termination of Service during the applicable Performance Period, Performance Shares and Performance Units for which the Performance Period was prescribed shall be forfeited; provided , however , that the Committee may provide, by rule or regulation or in any Award Agreement, or may determine in an individual case, that restrictions or forfeiture conditions relating to Performance Shares and Performance Units will be waived in whole or in part in the event of Terminations of Service resulting from specified causes, and the Committee may in other cases waive in whole or in part the forfeiture of Performance Shares and Performance Units.

(v) Payment . Each Performance Share or Performance Unit may be paid in whole Shares, or cash, or a combination of Shares and cash either as a lump sum payment or in installments, all as the Committee shall determine, at the time of grant of the Performance Share or Performance Unit or otherwise, commencing at the time determined by the Committee.

(vi) Restriction on Dividends . No dividends or Dividend Equivalents shall be paid on any Performance Share or Performance Unit until such time (if ever) as the performance criteria associated therewith have been met.

(g) Dividend Equivalents . The Committee is authorized to grant Dividend Equivalents to Eligible Persons. The Committee may provide, at the date of grant or thereafter, that Dividend Equivalents shall be paid or distributed when accrued or shall be deemed to have been reinvested in additional Shares, or other investment vehicles as the Committee may specify; provided , however , that, unless otherwise determined by the Committee, Dividend Equivalents (other than freestanding Dividend Equivalents) shall be subject to all conditions and restrictions of any underlying Awards to which they relate.

(h) Other Share-Based Awards . The Committee is authorized, subject to limitations under applicable law, to grant to Eligible Persons such other Awards that may be denominated or payable in, valued in whole or in part by reference to, or otherwise based on, or related to, Shares, as deemed by the Committee to be consistent with the purposes of this Plan, including, without limitation, unrestricted shares awarded purely as a “bonus” and not subject to any restrictions or conditions, other rights convertible or exchangeable into Shares,

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purchase rights for Shares, Awards with value and payment contingent upon performance of the Company or any other factors designated by the Committee, and Awards valued by reference to the performance of specified Subsidiaries or Affiliates. The Committee shall determine the terms and conditions of such Awards at date of grant or thereafter. Shares delivered pursuant to an Award in the nature of a purchase right granted under this Section 5(h) shall be purchased for such consideration, paid for at such times, by such methods, and in such forms, including, without limitation, cash, Shares, notes or other property, as the Committee shall determine. Cash awards, as an element of or supplement to any other Award under this Plan, shall also be authorized pursuant to this Section 5(h).

6. Certain Provisions Applicable to Awards .

(a) Stand-Alone, Additional, Tandem and Substitute Awards . Awards granted under this Plan may, in the discretion of the Committee, be granted to Eligible Persons either alone or in addition to, in tandem with, or in exchange or substitution for, any other Award granted under this Plan or any award granted under any other plan or agreement of the Company, any Subsidiary or Affiliate, or any business entity to be acquired by the Company or a Subsidiary or Affiliate, or any other right of an Eligible Person to receive payment from the Company or any Subsidiary or Affiliate. Awards may be granted in addition to or in tandem with such other Awards or awards, and may be granted either as of the same time as, or a different time from, the grant of such other Awards or awards. Subject to the provisions of Section 3(e) hereof prohibiting Option and SAR repricing without shareholder approval, the per Share exercise price of any Option, or grant price of any SAR, which is granted in connection with the substitution of awards granted under any other plan or agreement of the Company or any Subsidiary or Affiliate, or any business entity to be acquired by the Company or any Subsidiary or Affiliate, shall be determined by the Committee, in its discretion.

(b) Term of Awards . The term of each Award granted to an Eligible Person shall be for such period as may be determined by the Committee; provided , however , that in no event shall the term of any Option or SAR exceed a period of ten years from the date of its grant (or, in the case of ISOs, such shorter period as may be applicable under Section 422 of the Code).

(c) Form of Payment Under Awards . Subject to the terms of this Plan and any applicable Award Agreement, payments to be made by the Company or a Subsidiary or Affiliate upon the grant, maturation, or exercise of an Award may be made in such forms as the Committee shall determine at the date of grant or thereafter, including, without limitation, cash, Shares, notes or other property, and may be made in a single payment or transfer, in installments, or on a deferred basis, provided that any such deferral shall be intended to be in compliance with Section 409A of the Code. The Committee may make rules relating to installment or deferred payments with respect to Awards, including the rate of interest to be credited with respect to such payments, and the Committee may require deferral of payment under an Award if, in the sole judgment of the Committee, it may be necessary in order to avoid nondeductibility of the payment under Section 162(m) of the Code.

(d) Nontransferability . Awards shall not be transferable by an Eligible Person except by will or the laws of descent and distribution (except pursuant to a Beneficiary designation) and shall be exercisable during the lifetime of an Eligible Person only by such Eligible Person or his or her guardian or legal representative, provided that Awards that are NQSOs may be transferred or assigned by the optionee to the optionee’s spouse or descendent (any such spouse or descendent, an “Immediate Family Member”) or a corporation, partnership, limited liability company or trust so long as all of the shareholders, partners, members or beneficiaries thereof, as the case may be, are either the optionee or the optionee’s Immediate Family Member, provided , further , that (i) there may be no consideration for any such transfer and (ii) subsequent transfers of the transferred NQSO will be prohibited other than by will or the laws of descent and distribution. An Eligible Person’s rights under this Plan may not be pledged, mortgaged, hypothecated, or otherwise encumbered, and shall not be subject to claims of the Eligible Person’s creditors.

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(e) Noncompetition . The Committee may, by way of the Award Agreements or otherwise, establish such other terms, conditions, restrictions and/or limitations, if any, of any Award, provided they are not inconsistent with this Plan, including, without limitation, the requirement that the Participant not engage in competition with, solicit customers or employees of, or disclose or use confidential information of the Company or its Affiliates.

7. Performance Awards .

(a) Performance Awards Granted to Covered Employees . If the Committee determines that an Award (other than an Option or SAR) to be granted to an Eligible Person should qualify as “performance-based compensation” for purposes of Section 162(m) of the Code, the grant, vesting, exercise and/or settlement of such Award (each, a “Performance Award”) shall be contingent upon achievement of preestablished performance goals and other terms set forth in this Section 7(a).

(i) Performance Goals Generally . The performance goals for such Performance Awards shall consist of one or more business criteria and a targeted level or levels of performance with respect to each of such criteria, as specified by the Committee consistent with this Section 7(a). The performance goals shall be objective and shall otherwise meet the requirements of Section 162(m) of the Code and regulations thereunder (including Treasury Regulation 1.162-27 and successor regulations thereto), including the requirement that the level or levels of performance targeted by the Committee result in the achievement of performance goals being “substantially uncertain.” The Committee may determine that such Performance Awards shall be granted, vested, exercised and/or settled upon achievement of any one performance goal or that two or more of the performance goals must be achieved as a condition to grant, vesting, exercise and/or settlement of such Performance Awards. Performance goals may differ for Performance Awards granted to any one Participant or to different Participants.

(ii) Business Criteria . One or more of the following business criteria for the Company, on a consolidated basis, and/or for specified Subsidiaries or Affiliates or other business units or lines of business of the Company shall be used by the Committee in establishing performance goals for such Performance Awards: (1) earnings per share (basic or fully diluted); (2) revenues; (3) earnings, before or after taxes, from operations (generally or specified operations), or before or after interest expense, depreciation, amortization, incentives, or extraordinary or special items; (4) cash flow, free cash flow, cash flow return on investment (discounted or otherwise), net cash provided by operations, or cash flow in excess of cost of capital; (5) return on net assets, return on assets, return on investment, return on capital, return on equity; (6) economic value added; (7) operating margin or operating expense; (8) net income; (9) Share price or total stockholder return; (10) book value; (11) expense ratio; (12) operating income; and (13) strategic business criteria, consisting of one or more objectives based on meeting specified market penetration, geographic business expansion goals, cost targets, customer satisfaction, supervision of litigation and information technology, and goals relating to acquisitions or divestitures of Subsidiaries, Affiliates or joint ventures. The targeted level or levels of performance with respect to such business criteria may be established at such levels and in such terms as the Committee may determine, in its discretion, including in absolute terms, as a goal relative to performance in prior periods, or as a goal compared to the performance of one or more comparable companies or an index covering multiple companies.

(iii) Performance Period; Timing for Establishing Performance Goals; Per-Person Limit . Achievement of performance goals in respect of such Performance Awards shall be measured over a performance period, as specified by the Committee. A performance goal shall be established not later than the earlier of (A) 90 days after the beginning of any performance period applicable to such Performance Award or (B) the time 25% of such performance period has elapsed. In all cases, the maximum Performance Award of any Participant shall be subject to the limitation set forth in Section 4(b) or 7(a)(v), as applicable.

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(iv) Settlement of Performance Awards; Other Terms . Settlement of such Performance Awards shall be in cash, Shares, other Awards or other property, in the discretion of the Committee. The Committee may, in its discretion, reduce the amount of a settlement otherwise to be made in connection with such Performance Awards, but may not exercise discretion to increase any such amount payable to the Participant in respect of a Performance Award subject to this Section 7(a). Any settlement which changes the form of payment from that originally specified shall be implemented in a manner such that the Performance Award and other related Awards do not, solely for that reason, fail to qualify as “performance-based compensation” for purposes of Section 162(m) of the Code. The Committee shall specify the circumstances in which such Performance Awards shall be paid or forfeited (including by repurchase for a nominal amount, where required by Bermuda law) in the event of Termination of Service of the Participant or other event (including a Change in Control) prior to the end of a performance period or settlement of such Performance Awards.

(v) Maximum Annual Cash Award . The maximum amount payable upon settlement of a cash-settled Performance Unit (or other cash-settled Award) granted under this Plan that is intended to satisfy the requirements for “performance-based compensation” under Section 162(m) of the Code for any calendar year to any Eligible Person shall not exceed $3,000,000.

(b) Written Determinations . Determinations by the Committee as to the establishment of performance goals, the amount potentially payable in respect of Performance Awards, the level of actual achievement of the specified performance goals relating to Performance Awards and the amount of any final Performance Award shall be recorded in writing in the case of Performance Awards intended to qualify under Section 162(m) of the Code. Specifically, the Committee shall certify in writing, in a manner conforming to applicable regulations under Section 162(m), prior to settlement of each such Award, that the performance objective relating to the Performance Award and other material terms of the Award upon which settlement of the Award was conditioned have been satisfied.

8. Change in Control Provisions . Unless otherwise provided by the Committee at the time of the Award grant, in the event of a Change in Control, (i) all outstanding Awards pursuant to which the Participant may have rights the exercise of which is restricted or limited, shall become fully exercisable at the time of the Change in Control, and (ii) unless the right to lapse of restrictions or limitations is waived or deferred by a Participant prior to such lapse, all restrictions or limitations (including risks of forfeiture and deferrals) on outstanding Awards subject to restrictions or limitations under this Plan shall lapse, and all performance criteria and other conditions to payment of Awards under which payments of cash, Shares or other property are subject to conditions shall be deemed to be achieved or fulfilled at target (if applicable) and shall be waived by the Company at the time of the Change in Control. However, if so determined by the Board, notwithstanding the foregoing, an outstanding Award shall not be subject to the treatment provided in 8(a)(i) and 8(a)(ii) above if and to the extent such Award is, in connection with the Change in Control, either to be assumed by the successor company or parent thereof or to be replaced with comparable awards with respect to capital stock of the successor company or parent thereof, such comparability to be determined by the Committee.

9. General Provisions .

(a) Compliance with Legal and Trading Requirements . This Plan, the granting and exercising of Awards thereunder, and the other obligations of the Company under this Plan and any Award Agreement, shall be subject to all applicable federal, state and foreign laws, rules and regulations, and to such approvals by any stock exchange, regulatory or governmental agency as may be required. The Company, in its discretion, may postpone the issuance or delivery of Shares under any Award until completion of such stock exchange or market system listing or registration or qualification of such Shares or any required action under any state, federal or foreign law, rule or regulation as the Company may consider appropriate, and may require any Participant to make such representations and furnish such information as it may consider appropriate in connection with the issuance or delivery of Shares in compliance with applicable laws, rules and regulations. No provisions of this Plan shall be interpreted or construed to obligate the Company to register any Shares under federal, state or

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foreign law. The Shares issued under this Plan may be subject to such other restrictions on transfer as determined by the Committee.

(b) No Right to Continued Employment or Service . Neither this Plan nor any action taken thereunder shall be construed as giving any employee, consultant or director the right to be retained in the employ or service of the Company or any of its Subsidiaries or Affiliates, nor shall it interfere in any way with the right of the Company or any of its Subsidiaries or Affiliates to terminate any employee’s, consultant’s or director’s employment or service at any time.

(c) Taxes . The Company or any Subsidiary or Affiliate is authorized to withhold from any Award granted, any payment relating to an Award under this Plan, including from a distribution of Shares, or any payroll or other payment to an Eligible Person, amounts of withholding and other taxes due in connection with any transaction involving an Award, and to take such other action as the Committee may deem advisable to enable the Company and Eligible Persons to satisfy obligations for the payment of withholding taxes and other tax obligations relating to any Award. This authority shall include authority to withhold or receive Shares or other property and to make cash payments in respect thereof in satisfaction of an Eligible Person’s tax obligations; provided , however , that the amount of tax withholding to be satisfied by withholding Shares shall be limited to the minimum amount of taxes, including employment taxes, required to be withheld under applicable Federal, state and local law.

(d) Changes to this Plan and Awards . The Board may amend, alter, suspend, discontinue, or terminate this Plan or the Committee’s authority to grant Awards under this Plan without the consent of shareholders of the Company or Participants, except that any such amendment or alteration shall be subject to the approval of the Company’s shareholders (i) to the extent such shareholder approval is required under the rules of any stock exchange or automated quotation system on which the Shares may then be listed or quoted, or (ii) as it applies to ISOs, to the extent such shareholder approval is required under Section 422 of the Code; provided , however , that, without the consent of an affected Participant, no amendment, alteration, suspension, discontinuation, or termination of this Plan may materially and adversely affect the rights of such Participant under any Award theretofore granted to him or her. The Committee may waive any conditions or rights under, amend any terms of, or amend, alter, suspend, discontinue or terminate, any Award theretofore granted, prospectively or retrospectively; provided , however , that, without the consent of a Participant, no amendment, alteration, suspension, discontinuation or termination of any Award may materially and adversely affect the rights of such Participant under any Award theretofore granted to him or her.

(e) No Rights to Awards; No Shareholder Rights . No Eligible Person or employee shall have any claim to be granted any Award under this Plan, and there is no obligation for uniformity of treatment of Eligible Persons and employees. No Award shall confer on any Eligible Person any of the rights of a shareholder of the Company unless and until Shares are duly issued or transferred to the Eligible Person in accordance with the terms of the Award.

(f) Unfunded Status of Awards . This Plan is intended to constitute an “unfunded” plan for incentive compensation. With respect to any payments not yet made to a Participant pursuant to an Award, nothing contained in this Plan or any Award shall give any such Participant any rights that are greater than those of a general creditor of the Company; provided , however , that the Committee may authorize the creation of trusts or make other arrangements to meet the Company’s obligations under this Plan to deliver cash, Shares, other Awards, or other property pursuant to any Award, which trusts or other arrangements shall be consistent with the “unfunded” status of this Plan unless the Committee otherwise determines with the consent of each affected Participant.

(g) Nonexclusivity of this Plan . Neither the adoption of this Plan by the Board nor its submission to the shareholders of the Company for approval shall be construed as creating any limitations on the power of the Board to adopt such other incentive arrangements as it may deem desirable, including, without limitation,

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the granting of options and other awards otherwise than under this Plan, and such arrangements may be either applicable generally or only in specific cases.

(h) Not Compensation for Benefit Plans . No Award payable under this Plan shall be deemed salary or compensation for the purpose of computing benefits under any benefit plan or other arrangement of the Company for the benefit of its employees, consultants or directors unless the Company shall determine otherwise.

(i) No Fractional Shares . No fractional Shares shall be issued or delivered pursuant to this Plan or any Award. The Committee shall determine whether cash, other Awards, or other property shall be issued or paid in lieu of such fractional Shares or whether such fractional Shares or any rights thereto shall be forfeited (including by repurchase at a nominal price, where required by Bermuda law) or otherwise eliminated.

(j) Governing Law . The validity, construction, and effect of this Plan, any rules and regulations relating to this Plan, and any Award Agreement shall be determined in accordance with the laws of Bermuda without giving effect to principles of conflict of laws thereof.

(k) Effective Date; Plan Termination . This Plan became effective as of the Effective Date. This Plan shall terminate as to future awards on May 25, 2020 unless earlier terminated or extended by amendment.

(l) Section 409A . Awards under this Plan are intended to comply with, or be exempt from, the applicable requirements of Section 409A of the Code and shall be limited, construed and interpreted in accordance with such intent. Although the Company does not guarantee any particular tax treatment, to the extent that any Award is subject to Section 409A of the Code, it shall be paid in a manner that is intended to comply with Section 409A of the Code, including regulations and any other guidance issued by the Secretary of the Treasury and the Internal Revenue Service with respect thereto. In no event whatsoever shall the Company be liable for any additional tax, interest or penalties that may be imposed on a Participant by Section 409A of the Code or any damages for failing to comply with Section 409A of the Code.

(m) Titles and Headings . The titles and headings of the sections in this Plan are for convenience of reference only. In the event of any conflict, the text of this Plan, rather than such titles or headings, shall control.

1998 EMPLOYEE SHARE PURCHASE PLAN

(Amended and Restated through May 26, 2011)

1. Purpose . The purpose of this XOMA Ltd. 1998 Employee Share Purchase Plan (the “Plan”) is to provide employees of XOMA Ltd., a Bermuda company (the “Company”), with an opportunity to purchase common shares of the Company (“Common Shares”) through accumulated payroll deductions. It is the intention of the Company to have the Plan qualify as an “employee stock purchase plan” under Section 423 of the Internal Revenue Code of 1986, as amended (the “Code”). The provisions of the Plan, accordingly, shall be construed so as to extend and limit participation in a manner consistent with the requirements of that section of the Code.

(a) “ Board ” shall mean the Board of Directors of the Company.

(b) “ Committee ” shall mean the Compensation Committee of the Board or such other committee selected by the Board to administer the Plan.

(c) “ Compensation ” shall mean total cash compensation received by the Employee from the Company, including regular pay, overtime pay, and bonuses, and shall also include any pretax Employee cash or deferred contributions to a plan maintained by the Company which qualifies under Section 401(k) of the Code and any pretax Employee contributions to a plan maintained by the Company which qualifies under Section 125 of the Code.

(d) “ Employee ” shall mean any individual who is an employee of the Company for purposes of tax withholding under the Code whose customary employment with the Company is at least twenty (20) hours per week and more than five (5) months in any calendar year. For purposes of the Plan, the employment relationship shall be treated as continuing intact while the individual is on sick leave or other leave of absence approved by the Company. Where the period of leave exceeds ninety (90) days and the individual’s right to reemployment is not guaranteed either by statute or by contract, the employment relationship will be deemed to have terminated on the ninety-first (91st) day of such leave.

(e) “ Enrollment Date ” shall mean the first day of each Offering Period.

(f) “ Exercise Date ” shall mean the last day of each Offering Period.

(g) “ Fair Market Value ” shall mean, as of any date, the value of Common Shares determined as follows:

(1)

If the Common Shares are listed on any established stock exchange or a national market system, including without limitation the Nasdaq National Market, their Fair Market Value shall be the closing selling price for the Common Shares, as quoted on such exchange (or the exchange with the greatest volume of trading in Common Shares) or system on the date of such determination, as reported in The Wall Street Journal or such other source as the Committee deems reliable; or

(2)

If the Common Shares are quoted on the Nasdaq Stock Market (but not on the Nasdaq National Market), their Fair Market Value shall be the closing selling price for the Common Shares on the date of such determination, as reported in The Wall Street Journal or such other source as the Committee deems reliable; or

(3)	In the absence of an established market for the Common Shares, the Fair Market Value thereof shall be determined in good faith by the Committee.

(h) “ Offering Periods ” shall mean consecutive three (3) month periods commencing once every calendar quarter beginning on the first Trading Day on or after January 1, April 1, July 1 and October 1 of each year and ending on the last Trading Day prior to the end of such three (3) month period.

(i) “ Purchase Price ” shall mean with respect to new Offering Periods under the Plan commencing on or after January 1, 2005, the Purchase Price for such Offering Periods shall be an amount equal to 95% of the Fair Market Value of a Common Share on the Exercise Date for that Offering Period.

(j) “ Reserves ” shall mean the number of Common Shares covered by each option under the Plan which has not yet been exercised and the number of Common Shares which have been authorized for issuance under the Plan but not yet placed under option.

(k) “ Trading Day ” shall mean a day on which national stock exchanges and the Nasdaq Stock Market are open for trading.

(a) Any person who is an Employee on a given Enrollment Date shall be eligible to participate in the Plan.

(b) Any provisions of the Plan to the contrary notwithstanding, no Employee shall be granted an option under the Plan (i) if, immediately after the grant, such Employee would own shares (together with shares owned by any other person or entity that would be attributed to such Employee pursuant to Section 424(d) of the Code) of the Company (including, for this purpose, all shares of stock subject to any outstanding options to purchase such stock, whether or not currently exercisable and irrespective of whether such options are subject to the favorable tax treatment of Section 421(a) of the Code) possessing five percent (5%) or more of the total combined voting power or value of all classes of stock of the Company or of any parent (within the meaning of Section 424(e) of the Code) or subsidiary (within the meaning of Section 424(f) of the Code), or (ii) which permits his or her rights to purchase stock under all Offering Periods and all employee stock purchase plans (within the meaning of Section 423 of the Code) of the Company and its parents and subsidiaries to accrue at a rate which exceeds Twenty-Five Thousand Dollars ($25,000) worth of stock (determined at the Fair Market Value of the stock at the time such option is granted) for each calendar year in which such option is outstanding at any time. The limitation described in clause (ii) of the preceding sentence shall be applied in a manner consistent with Section 423(b)(8) of the Code.

4. Offering Periods . The Plan shall be implemented by concurrent Offering Periods with a new Offering Period commencing on the first Trading Day of each calendar quarter, or on such other date as the Committee shall determine, with such Offering Periods extending for twenty-four (24) months, or such other length as the Committee shall determine. The Committee shall have the power to change the duration of Offering Periods (including the commencement dates thereof) with respect to future offerings without stockholder approval if such change is announced at least fifteen (15) days prior to the scheduled beginning of the first Offering Period to be affected thereafter.

(a) An eligible Employee may become a participant in the Plan by completing a subscription agreement authorizing payroll deductions in a form prepared by the Company and filing it with the Company’s Human Resources Department at least one (1) day prior to the applicable Enrollment Date for a particular Offering Period, unless a different time for filing the subscription agreement is set by the Committee for all eligible Employees with respect to a given Offering Period.

(b) Payroll deductions for a participant shall commence on the first payroll date following the Enrollment Date and shall end on the last payroll date in the Offering Period to which such authorization is applicable, unless sooner terminated by the participant as provided in Section 10 hereof.

6. Payroll Deductions .

(a) At the time a participant files his or her subscription agreement, he or she shall elect to have payroll deductions made on each payday during the Offering Period in an amount not exceeding twenty percent (20%) (or such other lesser percentage, applied uniformly to all participants, as an executive officer of the Company shall set), in whole multiples of one percent (1%), of the Compensation which he or she receives on each payday during the Offering Period. The aggregate amount of payroll deductions for all concurrent Offering Periods shall not exceed twenty percent (20%) (or such lesser percentage, applied uniformly to all participants, as an executive officer of the Company shall set).

(b) All payroll deductions made for a participant shall be credited to his or her account under the Plan and will be withheld in whole percentages only. A participant may not make any additional payments into such account.

(c) Once an Offering Period has commenced, a participant may decrease, but not increase, the rate of his or her payroll deductions for that Offering Period once per calendar quarter by filing a new subscription agreement at least one (1) day prior to the beginning of the calendar quarter (or such other time set by the Committee for all eligible Employees with respect to a given Offering Period), which decrease shall become effective at the beginning of the next calendar quarter; provided , however , that a participant may discontinue his or her participation in the Plan, as provided in Section 10 hereof, at any time during the Offering Period prior to the Exercise Date. During an Offering Period, a participant may elect to have new or additional payroll deductions made with respect to the next beginning Offering Period, by completing or filing with the Company an additional subscription agreement, at least one (1) day prior to the beginning of the next Offering Period (or such other time set by the Committee for all eligible Employees with respect to a given Offering Period), authorizing a payroll deduction rate with respect to the new Offering Period. A participant’s subscription agreement shall remain in effect for other Offering Periods, but separate subscription agreements are required for each Offering Period.

(d) Notwithstanding the foregoing, a participant’s payroll deductions for each Offering Period may be decreased to 0% at any time, to the extent necessary to comply with Section 423(b)(8) of the Code and Section 3(b) hereof.

(e) At the time the option is exercised, in whole or in part, or at the time some or all of the Company’s Common Shares issued under the Plan are disposed of, the participant must make adequate provisions for the Company’s federal, state, or other tax withholding obligations, if any, which arise upon the exercise of the option or the disposition of the Common Shares. At any time, the Company may, but will not be obligated to, withhold from the participant’s compensation the amount necessary for the Company to meet applicable withholding obligations.

7. Grant of Option . On the Enrollment Date of each Offering Period, each eligible Employee participating in such Offering Period shall be granted an option to purchase on the Exercise Date of such Offering Period (at the applicable Purchase Price) up to a number of Common Shares determined by dividing such Employee’s payroll deductions accumulated with respect to that Offering Period prior to such Exercise Date and retained in the participant’s account as of the Exercise Date by the applicable Purchase Price; provided, however, that in no event shall an Employee be permitted to purchase during each Offering Period and with respect to such Offering Period more than 3,333 Common Shares; and provided, further, that such purchase shall be subject to the limitations set forth in Sections 3(b) and 12 hereof. Exercise of the option with respect to that Offering Period shall occur as provided in Section 8 hereof, unless the participant has withdrawn pursuant to Section 10 hereof, and the option with respect to that Offering Period shall expire on the last day of the Offering Period.

8. Exercise of Option . Unless a participant has withdrawn from the Plan as provided in Section 10 hereof, his or her option for the purchase of Common Shares will be exercised automatically on the Exercise Date, and, subject to the limitations set forth in Sections 3(b), 7 and 12 hereof, the maximum number of full shares subject to option shall be purchased for such participant at the applicable Purchase Price with the accumulated payroll deductions in his or her account with respect to that Offering Period. Unless otherwise approved by the Committee, no fractional shares will be purchased. Unless acquisition of fractional shares has been so approved, any payroll deductions accumulated in a participant’s account which are not sufficient to purchase a full Common Share shall be retained in the participant’s account for the next expiring Offering Periods, subject to earlier withdrawal by the participant as provided in Section 10 hereof. Any other monies left over in a participant’s account after the Exercise Date shall be returned to the participant. During a participant’s lifetime, a participant’s option to purchase shares hereunder is exercisable only by the participant.

9. Issuance; Delivery; Restriction . The Common Shares purchased for a participant on the last day of an Offering Period shall be deemed to have been issued by the Company for all purposes as of the Exercise Date. Prior to such date, none of the rights and privileges of a shareholder of the Company shall exist with respect to such Common Shares. The registrar for the Company shall be instructed to make entries on its books and records evidencing that Common Shares issued hereunder have been duly issued as of each pertinent Exercise Date; provided , however , that an employee may in the alternative elect in writing to receive a stock certificate representing the amount of such shares so acquired; and provided, further, that, regardless of whether an employee elects to receive such stock certificates, the Committee may direct the Company to distribute stock certificates representing the amount of shares acquired to any or all employees. Notwithstanding the foregoing, delivery of certificates representing Common Shares or transfer to or for the account of any participant under the Plan may be conditioned upon the agreement of such participant to allow federal income tax withholdings as may be required to be made by the Company.

10. Withdrawal; Termination of Employment .

(a) A participant may withdraw all but not less than all the payroll deductions credited to his or her account and not yet used to exercise his or her option under the Plan with respect to each Offering Period at any time prior to the last business day of the Offering Period by giving written notice to the Company in a form prepared by the Company. All of the participant’s payroll deductions credited to his or her account will be paid to such participant promptly after receipt of notice of withdrawal and such participant’s option for the Offering Period will be automatically terminated, and no further payroll deductions for the purchase of shares will be made during the Offering Period with respect to such Offering Period. If a participant withdraws from the Plan with respect to one Offering Period during an Offering Period, he or she may resume participation for a subsequent Offering Period by delivering to the Company a new subscription agreement at least fifteen (15) days prior to the Enrollment Date for such Offering Period and he or she may continue in the Plan with respect to other Offering Periods that have already begun.

(b) Upon a participant’s ceasing to be an Employee, for any reason, he or she will be deemed to have elected to withdraw from the Plan and the payroll deductions credited to such participant’s account during the current Offering Periods but not yet used to exercise the option will be returned to such participant or, in the case of his or her death, to the person or persons entitled thereto under Section 14 hereof, and such participant’s option will be automatically terminated.

(c) A participant’s withdrawal from an Offering Period will not have any effect upon his or her eligibility to participate in any similar plan which may hereafter be adopted by the Company or in subsequent and all other Offering Periods.

11. Interest . No interest or other increment shall accrue or be payable with respect to any of the payroll deductions of a participant in the Plan.

(a) The maximum number of Common Shares which shall be made available for sale under the Plan shall be 233,333 shares, subject to adjustment upon changes in capitalization of the Company as provided in Section 18 hereof. Such Common Shares may be authorized but unissued shares or shares purchased in the open market.

(b) If on a given Exercise Date the number of Common Shares with respect to which options are to be exercised exceeds the number of shares then available under the Plan, the Committee shall make a pro-rata allocation of the shares remaining available for purchase in as uniform a manner as shall be practicable and as it shall determine to be equitable, and the balance of the payroll deductions accumulated in the participant’s account shall be returned to the participant.

(c) No participant will have an interest or voting right in Common Shares covered by his or her option until such option has been exercised.

(d) Common Shares to be delivered to a participant under the Plan will be registered in the name of the participant or in the name of the participant and his or her spouse.

13. Administration . The Plan shall be administered by the Committee. The Committee shall have full and exclusive discretionary authority to construe, interpret and apply the terms of the Plan, to determine eligibility and to adjudicate all disputed claims filed under the Plan. Every finding, decision and determination made by the Committee shall, to the full extent permitted by law, be final and binding upon all parties. Members of the Committee shall not be permitted to participate in the Plan.

14. Designation of Beneficiary .

(a) A participant may file a written designation of a beneficiary who is to receive any Common Shares and cash, if any, from the participant’s account under the Plan in the event of such participant’s death subsequent to an Exercise Date on which the option is exercised but prior to delivery to such participant of such shares or cash. In addition, a participant may file a written designation of a beneficiary who is to receive any cash from the participant’s account under the Plan in the event of such participant’s death prior to exercise of the option. If a participant is married and the designated beneficiary is not the spouse, spousal consent shall be required for such designation to be effective.

(b) Such designation of beneficiary may be changed by the participant at any time by written notice. In the event of the death of a participant and in the absence of a beneficiary validly designated

under the Plan who is living at the time of such participant’s death, the Company shall deliver such Common Shares or cash to the executor or administrator of the estate of the participant, or if no such executor or administrator has been appointed (to the knowledge of the Company), the Company, in its discretion, may deliver such shares or cash to the spouse or to any one or more dependents or relatives of the participant, or if no spouse, dependent or relative is known to the Company, then to such other person as the Company may designate.

15. Transferability . Neither payroll deductions credited to a participant’s account nor any rights with regard to the exercise of an option or to receive Common Shares under the Plan may be assigned, transferred, pledged or otherwise disposed of in any way (other than by will, the laws of descent and distribution or as provided in Section 14 hereof) by the participant. Any such attempt at assignment, transfer, pledge or other disposition shall be without effect, except that the Company may treat such act as an election to withdraw funds from an Offering Period in accordance with Section 10 hereof.

16. Use of Funds . All payroll deductions received or held by the Company under the Plan may be used by the Company for any corporate purpose, and the Company shall not be obligated to segregate such payroll deductions.

17. Reports . Individual accounts will be maintained for each participant in the Plan. Statements of account will be given to participating Employees at least annually, within such time as the Committee may reasonably determine, which statements will set forth the amounts of payroll deductions, the Purchase Price, the number of shares purchased and the remaining cash balance, if any.

18. Adjustments Upon Changes in Capitalization .

(a) Changes in Capitalization . The Reserves, the maximum number of Common Shares an Employee is permitted to purchase in any Offering Period under Section 7, and the price per Common Share covered by each option under the Plan which has not yet been exercised shall be proportionately adjusted for any increase or decrease in the number of issued Common Shares resulting from a share split, reverse share split, share dividend, combination or reclassification of the Common Shares, or any other increase or decrease in the number of Common Shares effected without receipt of consideration by the Company; provided , however , that conversion of any convertible securities of the Company shall not be deemed to have been effected without receipt of consideration. Such adjustment shall be made by the Committee, whose determination in that respect shall be final, binding and conclusive. Except as expressly provided herein, no issuance by the Company of shares of any class, or securities convertible into shares of any class, shall affect, and no adjustment by reason thereof shall be made with respect to, the number or price of Common Shares subject to an option.

(b) Dissolution or Liquidation . In the event of the proposed dissolution or liquidation of the Company, the Offering Period will terminate immediately prior to the consummation of such proposed action, unless otherwise provided by the Committee.

(c) Amalgamation, Merger or Asset Sale . In the event of a proposed sale of all or substantially all of the assets of the Company, or the amalgamation or merger of the Company with or into another corporation, all options under the Plan shall be assumed or an equivalent option shall be substituted by such successor corporation or a parent or subsidiary of such successor corporation, unless the Committee determines, in the exercise of its sole discretion and in lieu of such assumption or substitution, to shorten the Offering Periods then in progress by setting new Exercise Dates (“New Exercise Dates”). If the Committee shortens the Offering Period then in progress in lieu of assumption or substitution in the event of an amalgamation, merger or sale of assets, the Committee shall notify each participant in writing, at least fifteen (15) days prior to the New Exercise Dates, that the Exercise Dates for his or her option have been changed to the New Exercise Dates and that his or her options will be exercised automatically on the New Exercise Dates, unless prior to such dates he or she has

withdrawn from the Offering Periods as provided in Section 10 hereof. For purposes of this paragraph, options granted under the Plan shall be deemed to be assumed if, following the sale of assets, amalgamation or merger, the options confer the right to purchase, for each option share subject to the option immediately prior to the sale of assets, amalgamation or merger, the consideration (whether stock, cash or other securities or property) received in the sale of assets, amalgamation or merger by holders of Common Shares for each Common Share held on the effective date of the transaction (and if such holders were offered a choice of consideration, the type of consideration chosen by the holders of a majority of the outstanding Common Shares); provided , however , that if such consideration received in the sale of assets, amalgamation or merger was not solely common shares of the successor corporation or its parent (as defined in Section 424(e) of the Code), the Committee may, with the consent of the successor corporation and the participant, provide for the consideration to be received upon exercise of the options to be solely common shares of the successor corporation or its parent equal in fair market value to the per share consideration received by holders of Common Shares in the sale of assets, amalgamation or merger.

19. Amendment or Termination .

(a) The Board may at any time and for any reason terminate or amend the Plan. Except as provided in Section 18 hereof, no such termination may adversely affect options previously granted; provided , however , that Offering Periods may be terminated by the Board on any Exercise Date if the Board determines that the termination of the Plan is in the best interests of the Company and its stockholders. Except as provided in Section 18 hereof, no amendment may make any change in any option theretofore granted which adversely affects the rights of any participant. To the extent necessary to comply with Rule 16b-3 promulgated under the Securities Exchange Act of 1934, as amended, or Section 423 of the Code (or any successor rule or provision or any other applicable law or regulation), the Company shall obtain stockholder approval in such a manner and to such a degree as required.

(b) Without shareholder consent and without regard to whether any participant rights may be considered to have been adversely affected, the Committee shall be entitled to change the Offering Periods, limit the frequency or number of changes in the amount withheld during the Offering Periods, permit payroll withholding in excess of the amount designated by a participant in order to adjust for delays or mistakes in the Company’s processing of properly completed withholding elections, establish reasonable waiting and adjustment periods or accounting and crediting procedures to ensure that amounts applied toward the purchase of Common Shares for each participant properly correspond with amounts withheld from the participant’s Compensation, and establish such other limitations or procedures as the Committee finds, in its sole discretion, advisable and consistent with the Plan.

20. Notices . All notices or other communications by a participant to the Company under or in connection with the Plan shall be deemed to have been duly given when received in the form specified by the Company at the location, or by the person, designated by the Company for the receipt thereof.

21. Conditions Upon Issuance of Shares . Shares shall not be issued with respect to an option unless the exercise of such option and the issuance and delivery of such shares pursuant thereto shall comply with all applicable provisions of law, domestic or foreign, including, without limitation, the Securities Act of 1933, as amended, the Securities Exchange Act of 1934, as amended, the rules and regulations promulgated thereunder and the requirements of any stock exchange upon which the shares may then be listed, and shall be further subject to the approval of counsel for the Company with respect to such compliance. As a condition to the exercise of an option, the Company may require the person exercising such option to represent and warrant at the time of any such exercise that the shares are being purchased only for investment and without any present intention to sell or distribute such shares if, in the opinion of counsel for the Company, such a representation is required by any of the aforementioned applicable provisions of law.

22. Term of Plan . The Plan shall become effective on February 25, 1998 (the “Effective Date”), subject to its approval by the stockholders of the Company within twelve (12) months after its adoption by the Board. It shall continue in effect until terminated under Section 19 hereof. The Plan was amended, effective as of May 20, 1998, by the Board of Directors to clarify the limits of contributions. The Plan was restated by the Board of Directors on February 24, 1999, effective December 31, 1998, to reflect the change of domicile of the Company from Delaware to Bermuda. The Plan was again restated by the Board of Directors on July 26, 2000, effective June 30, 2000, to make certain administrative corrections.

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the XOMA Ltd. 2010 Long Term Incentive and Share Award Plan and the XOMA Ltd. 1998 Employee Share Purchase Plan of our reports dated March 10, 2011, with respect to the consolidated financial statements of XOMA Ltd., and the effectiveness of internal control over financial reporting of XOMA Ltd., included in its Annual Report (Form 10-K) for the year ended December 31, 2010, filed with the Securities and Exchange Commission.

/s/ ERNST & YOUNG LLP

San Francisco, California