Exhibit 99.1

INVESTOR RIGHTS AGREEMENT

By and Among

Plug Power Inc.

and

The Restricted Parties

as defined herein

Dated as of June 29, 2006

TABLE OF CONTENTS

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INVESTOR RIGHTS AGREEMENT

THIS INVESTOR RIGHTS AGREEMENT (this “ Agreement ”) is made as of June 29, 2006, by and among Plug Power Inc., a Delaware corporation (the “ Company ”), Smart Hydrogen Inc., a BVI Business Company incorporated under the laws of the British Virgin Islands (“ Smart Hydrogen ”), Clayburn Development Inc., a company organized under the laws of the British Virgin Islands (“ Clayburn ”), Branton Limited, a company organized under the laws of the Commonwealth of the Bahamas (“ Branton ”), ZAO Interros Holding Company, a company organized under the laws of the Russian Federation (“ Interros ”), and any other Person who from time to time becomes party to this Agreement as a Restricted Party in accordance with the terms hereof (collectively, together with Smart Hydrogen, Clayburn, Branton and Interros, the “ Restricted Parties ,” and each of them, a “ Restricted Party ”).

RECITALS

WHEREAS, on the date hereof, Smart Hydrogen is purchasing shares of the Company’s Class B Capital Stock, a series of preferred stock, par value $.01 per share (the “ Class B Capital Stock ”), pursuant to that certain Stock Purchase Agreement dated as of April 10, 2006 by and between the Company and Smart Hydrogen (the “ Stock Purchase Agreement ”);

WHEREAS, it is a condition to the obligations of Smart Hydrogen and the Company under the Stock Purchase Agreement that this Agreement be executed by the parties hereto, and the parties hereto are willing to execute this Agreement and be bound by the provisions hereof; and

WHEREAS, the parties hereto desire to agree upon the terms on which the securities of the Company, now or hereafter outstanding and held by them, will be held, transferred and voted on certain matters, and to provide for certain rights of Smart Hydrogen and the holders of Class B Capital Stock.

AGREEMENT

NOW, THEREFORE, in consideration of the foregoing and the mutual covenants and agreements hereinafter set forth, and for other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereto, intending to be legally bound, hereby agree as follows:

ARTICLE I—DEFINITIONS AND INTERPRETATION

Section 1.1. Construction of Terms . As used herein, the masculine, feminine or neuter gender, and the singular or plural number, shall be deemed to be or to include the other genders or number, as the case may be, whenever the context so indicates or requires.

Section 1.2. Terms Not Defined . Capitalized terms used herein and not otherwise defined shall have the meanings ascribed to them in the Stock Purchase Agreement.

Section 1.3. Defined Terms . The following capitalized terms, as used in this Agreement, shall have the meanings set forth below:

“ 5-Year Standstill Period ” shall have the meaning set forth in Section 3.3.

“ Acquisition Issuance ” shall have the meaning set forth in Section 5.5.

“ Acquisition Issuance Notice ” shall have the meaning set forth in Section 6.3.

“ Affiliate ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Applicable Shares ” shall have the meaning set forth in the Charter.

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“ Board of Directors ” shall mean the Board of Directors of the Company.

“ Branton ” shall have the meaning set forth in the introductory paragraph hereof.

“ Business Day ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Buyer Disclosure Letter ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Buyer NDA ” means that certain Confidentiality Agreement, dated as of March 13, 2006, by and among Smart Hydrogen and the Company.

“ Chairperson ” shall have the meaning set forth in Section 8.11(a).

“ Charter ” shall mean the Company’s Amended and Restated Certificate of Incorporation in effect as of the date hereof, including the Certificate of Designations creating the Class B Capital Stock, as amended from time to time.

“ Class B Capital Stock ” shall have the meaning set forth in the recitals hereof.

“ Class B Director ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Class B Percentage ” shall have the meaning set forth in the Charter.

“ Class B Period ” shall have the meaning set forth in the Charter.

“ Class B Shares ” shall mean the shares of Class B Capital Stock, together with any shares issued or issuable with respect thereto (whether by way of a stock dividend or stock split or in exchange for or in replacement of such shares or otherwise in connection with a combination of shares, recapitalization, merger, consolidation or other corporate reorganization).

“ Clayburn ” shall have the meaning set forth in the introductory paragraph hereof.

“ Closing ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Closing Date ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Common Stock ” shall mean the Common Stock and any other common equity securities issued by the Company, and any other shares of stock issued or issuable with respect thereto (whether by way of a stock dividend or stock split or in exchange for or upon conversion of such shares or otherwise in connection with a combination of shares, recapitalization, merger, consolidation or other corporate reorganization).

“ Company ” shall mean Plug Power Inc., a Delaware corporation and any successors thereto.

“ Company Acceptance Notice ” shall have the meaning set forth in Section 3.4(b).

“ Company NDA ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Company Option Period ” shall have the meaning set forth in Section 3.4(b).

“ Competitor ” shall mean any Person other than the Company or its subsidiaries that is engaged in, or proposes to engage in, the business of providing, manufacturing, designing, developing, selling or manufacturing fuel cell technology, including fuel reforming and/or processing technology, for any application.

“ control ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Co-Sale Acceptance Notice ” shall have the meaning set forth in Section 4.2.

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“ Co-Sale Election Period ” shall have the meaning set forth in Section 4.2.

“ Co-Sale Notice ” shall have the meaning set forth in Section 4.1.

“ Co-Sale Option ” shall have the meaning set forth in Section 4.1.

“ Co-Sale Shares ” shall have the meaning set forth in Section 4.3.

“ Co-Sale Transaction ” shall have the meaning set forth in Section 4.1.

“ Dispute ” shall have the meaning set forth in Section 8.11(a).

“ Disputing Parties ” shall have the meaning set forth in Section 8.11(a).

“ EIP Shares ” shall have the meaning set forth in Section 6.4.

“ Equity Incentive Plans ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Exchange Act ” shall mean the Securities Exchange Act of 1934, as amended.

“ Interros ” shall have the meaning set forth in the introductory paragraph hereof.

“ Interros Principals ” shall have the meaning set forth in the Buyer Disclosure Letter.

“ Issuance Notice ” shall have the meaning set forth in Section 5.1.

“ Large Acquisition Issuance ” shall have the meaning set forth in Section 6.1.

“ Non-Party Investor Affiliates ” shall mean all Affiliates of Smart Hydrogen or any other holder of Applicable Shares other than the Restricted Parties, including, without limitation, Norilsk Nickel, the Interros Principals and their Affiliates.

“ Norilsk Nickel ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Notice Date ” shall have the meaning set forth in Section 6.4.

“ Ownership Percentage ” of a Restricted Party as of a particular date shall mean the number of Applicable Shares held by such Restricted Party as of such date divided by the Total Outstanding Shares as of such date.

“ Participating Investor ” shall have the meaning set forth in Section 5.1.

“ Permitted Transferee ” shall have the meaning set forth in Section 3.5.

“ Person ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Preemptive Acceptance Notice ” shall have the meaning set forth in Section 5.2.

“ Preemptive Election Period ” shall have the meaning set forth in Section 5.2.

“ Preemptive Right ” shall have the meaning set forth in Section 5.1.

“ Private Sale ” shall mean any sale other than a sale: (i) in accordance with Rule 144 under the Securities Act, (ii) in an underwritten public offering or (iii) registered under the Securities Act and sold in accordance with the manner of sale requirements set forth in Rule 144(f) under the Securities Act.

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“ Restricted Parties ” shall have the meaning set forth in the introductory paragraph hereof.

“ ROFO Notice ” shall have the meaning set forth in Section 3.4.

“ ROFO Price ” shall have the meaning set forth in Section 3.4.

“ ROFO Shares ” shall have the meaning set forth in Section 3.4.

“ Rules ” shall have the meaning set forth in Section 8.11(a).

“ Sale Transaction ” shall have the meaning set forth in Section 7.4.

“ Securities Act ” shall mean the Securities Act of 1933, as amended.

“ Shares ” shall mean, at any time, shares of (i) Common Stock, (ii) Preferred Stock, and (iii) any other equity securities now or hereafter issued by the Company, and any other shares of stock issued or issuable with respect thereto (whether by way of a stock dividend, stock split or in exchange for or upon conversion of such shares or otherwise in connection with a combination of shares, recapitalization, merger, consolidation or other corporate reorganization).

“ Small Acquisition Issuance ” shall have the meaning set forth in Section 6.2.

“ Smart Hydrogen ” shall have the meaning set forth in the introductory paragraph hereof.

“ Stock Issuance ” shall have the meaning set forth in Section 5.1.

“ Stock Issuance Price ” shall have the meaning set forth in Section 5.2.

“ Stock Purchase Agreement ” shall have the meaning set forth in the recitals hereof.

“ Top Up Exercise Notice ” shall have the meaning set forth in Section 6.3.

“ Top Up Period ” shall have the meaning set forth in Section 6.4.

“ Top Up Right ” shall have the meaning set forth in Section 6.4.

“ Total Outstanding Shares ” shall have the meaning set forth in the Charter.

“ Transaction Agreements ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Transfer ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Transferring Investors ” shall have the meaning set forth in Section 3.4.

“ Tribunal ” shall have the meaning set forth in Section 8.11(a).

ARTICLE II—REPRESENTATIONS AND WARRANTIES

Section 2.1. Representations and Warranties of the Restricted Parties . Each of the Restricted Parties, individually and not jointly, hereby represents and warrants to the Company as follows: (a) such Restricted Party has full authority and power under its charter, by-laws, limited liability company agreement, governing partnership agreement or comparable document (if applicable) to enter into this Agreement and perform its obligations hereunder; (b) this Agreement constitutes the valid and binding obligation of such Restricted Party enforceable against it in accordance with its terms, except: (i) as limited by applicable bankruptcy, insolvency,

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reorganization, moratorium and other laws of general application affecting enforcement of creditors’ rights generally and (ii) as limited by laws relating to the availability of specific performance, injunctive relief, or other equitable remedies; and (c) the execution, delivery and performance by such Restricted Party of this Agreement does not and will not violate any laws, rules or regulations of the United States or any state or other foreign or domestic jurisdiction applicable to such Restricted Party, does not and will not conflict with any material contracts entered into by such Restricted Party, or require such Restricted Party to obtain any approval, consent or waiver of, or to make any filing with, any Person that has not been obtained or made.

Section 2.2. Representations and Warranties of the Company . The Company hereby represents and warrants to the Restricted Parties as follows: (a) the Company has full corporate authority and power under the Charter and by-laws to enter into this Agreement and perform its obligations hereunder; (b) this Agreement constitutes the valid and binding obligation of the Company enforceable against it in accordance with its terms, except: (i) as limited by applicable bankruptcy, insolvency, reorganization, moratorium and other laws of general application affecting enforcement of creditors’ rights generally and (ii) as limited by laws relating to the availability of specific performance, injunctive relief, or other equitable remedies; and (c) the execution, delivery and performance by the Company of this Agreement does not and will not violate any laws, rules or regulations of the United States or any state or other foreign or domestic jurisdiction applicable to the Company, does not and will not conflict with any material contracts entered into by the Company, or require the Company to obtain any approval, consent or waiver of, or to make any filing with, any Person that has not been obtained or made.

ARTICLE III—RESTRICTIONS ON TRANSFER

Section 3.1. Blackout Period . Except as otherwise permitted by Section 3.7 or Article IV of this Agreement or upon the Company’s prior written consent (in its sole and absolute discretion), from and after the date hereof and until the date that is 18 months after the Closing Date, no Restricted Party shall Transfer all or any portion of the Applicable Shares owned by such Restricted Party except to a Permitted Transferee in accordance with Section 3.5 below.

Section 3.2. Restriction Relating to Private Sales of Shares . Except as otherwise permitted by Section 3.7 or Article IV of this Agreement or upon the Company’s prior written consent (in its sole and absolute discretion), from and after the date hereof and until the 2 ^nd anniversary of the Closing Date, none of the Restricted Parties shall sell in a Private Sale any Shares to any Person other than a Permitted Transferee in accordance with Section 3.5 below if after giving effect to such sale, such Person would (together with its Affiliates) beneficially own (as defined in Rule 13d-3 under the Exchange Act), in the aggregate, 5% or more of the Shares then outstanding.

Section 3.3. Restriction Relating to Sales of Shares to Competitors . Except as otherwise permitted by Section 3.7 or Article IV of this Agreement or upon the Company’s prior written consent (in its sole and absolute discretion), from and after the date hereof and until the 5 ^th anniversary of the Closing Date (such period being referred to as the “ 5-Year Standstill Period ”), none of the Restricted Parties shall Transfer any Shares to a Competitor in a Private Sale.

Section 3.4. Company Right of First Offer . If, at any time after the date hereof until the 2 ^nd anniversary of the Closing Date, one or more Restricted Parties (the “ Transferring Investors ”) desire to Transfer any Shares in a Private Sale (other than a Transfer to a Permitted Transferee or pursuant to Section 3.7 or Article IV), such Transferring Investors will give notice (the “ ROFO Notice ”) to the Company that such Transferring Investors desire to make such a Transfer and that sets forth the number of Shares proposed to be Transferred by such Transferring Investors (the “ ROFO Shares ”), the cash price per share that such Transferring Investors propose to be paid for such ROFO Shares (the “ ROFO Price ”) and any other material terms sought by such Transferring Investors.

(a) ROFO Notice . The Transferring Investors’ ROFO Notice shall constitute an irrevocable offer to sell the ROFO Shares to the Company, on the basis described below, at the ROFO Price and on the other terms set forth in the ROFO Notice.

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(b) Company ROFO Option . The Company shall have the option to offer to purchase all (but not less than all) of the ROFO Shares in accordance with this Section 3.4. At any time within 30 days after receipt by the Company of the ROFO Notice (the “ Company Option Period ”), the Company may elect to accept the offer to purchase all (but not less than all) of the ROFO Shares by giving written notice of such election (the “ Company Acceptance Notice ”) to all of the Transferring Investors within the Company Option Period. The Company Acceptance Notice shall be irrevocable and shall constitute a valid, legally binding and enforceable agreement for the sale and purchase of the ROFO Shares on the terms described in the ROFO Notice. If the Company accepts the offer to purchase all of the ROFO Shares in accordance with this Section 3.4, the closing for such purchase by the Company under this Section 3.4(b) shall take place within 20 days following the expiration of the Company Option Period, at the offices of the Company or on such other date or at such other place as may be agreed to by the Transferring Investors and the Company. At the closing, the Company shall pay the ROFO Price for the ROFO Shares, in immediately available funds by wire transfer to accounts of the Transferring Investors designated by the Transferring Investor(s) by notice to the Company, and the Transferring Investors will deliver the certificates representing the ROFO Shares to the Company properly endorsed for transfer.

(c) Sale to Third Party . In the event that (i) the Company does not timely elect to exercise its right to purchase all of the ROFO Shares under this Section 3.4 prior to the end of the Company Option Period or (ii) fails to consummate the purchase of ROFO Shares in accordance with the terms of this Section 3.4, then the Transferring Investors, subject to the other restrictions contained in this Agreement (if any), may sell all (but not less than all) of the ROFO Shares to any other Person in a Private Sale on the terms and conditions described in the ROFO Notice (or on terms and conditions more favorable to the Transferring Investors) during the 75-day period immediately following the expiration of the Company Option Period. Promptly after such Transfer, the Transferring Investors shall notify the Company of the consummation thereof and shall furnish such evidence of the completion and time of completion of the Transfer and of the terms thereof as may reasonably be requested by the Company. If the Transferring Investors have not Transferred the ROFO Shares within 75 days after the expiration of the Company Option Period, the Transferring Investor must send a new ROFO Notice and again comply with the provisions of this Section 3.4 prior to effecting a Transfer of Shares in a Private Sale during the time period within which such Transfers are restricted by this Section 3.4.

Section 3.5. Permitted Transfers . The restrictions on Transfer of Shares contained in this Article III shall not apply to Transfers of Shares to the following Persons (each a “ Permitted Transferee ”):

(a) Smart Hydrogen, Interros, Clayburn, or Branton;

(b) any wholly-owned subsidiary of Smart Hydrogen, Interros, Branton, or Clayburn; provided that such subsidiary (i) agrees to be bound by the provisions of this Agreement as a Restricted Party and executes and delivers a Joinder Agreement evidencing such agreement in the form of Exhibit A attached hereto or such other form as the Company and such subsidiary may agree to (“Joinder Agreement”), and (ii) has not previously taken any action that would have been a breach of the provisions of this Agreement if such subsidiary had been subject to this Agreement as a Restricted Party at that time; and

(c) any other Person to whom the Company may, in its absolute sole discretion, agree in writing;

provided that no Person shall be deemed to be a Permitted Transferee if such Person, (i) is controlled, directly or indirectly, by a Person other than (A) Smart Hydrogen or an Affiliate of Smart Hydrogen as of the date hereof or (B) another Person that is wholly-owned and controlled solely by Smart Hydrogen or an Affiliate of Smart Hydrogen as of the date hereof or (ii) is not controlled, directly or indirectly, by one or both of the Interros Principals.

Notwithstanding anything to the contrary in this Agreement or any failure by a Permitted Transferee to execute a Joinder Agreement, such Transferee shall be bound by the provisions of this Agreement as a Restricted Party, whether or not they so agree in writing.

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Section 3.6. Effect of Prohibited Transfers . If any Transfer is made or attempted contrary to the provisions of this Agreement, such purported Transfer shall be void ab initio ; the Company and the other parties hereto shall have, in addition to any other legal or equitable remedies which it may have, the right to enforce the provisions of this Agreement by actions for specific performance (to the extent permitted by law); and the Company shall have the right to refuse to recognize any Transferee as one of its stockholders for any purpose.

Section 3.7. Exception to Transfer Restrictions . Notwithstanding any of the restrictions on Transfer contained in Article III, each of the Restricted Parties and Non-Party Investor Affiliates shall be permitted to Transfer any securities of the Company beneficially owned by it pursuant to any “tender offer” (as such term is used in the Exchange Act), exchange offer, merger, business combination, restructuring, or acquisition of the Company that is recommended by the Board of Directors.

Section 3.8. Joinder; Affiliates . Upon the execution and delivery of a Joinder Agreement by a Transferee of Shares in accordance with this Article III, the Company shall promptly countersign and deliver such Joinder Agreement to such Transferee; provided that such Transferee shall be bound by such Joinder Agreement regardless of whether it is countersigned and delivered by the Company. Additionally, in the event that an Affiliate of a Restricted Party acquires any Shares from a Restricted Party during the 5-Year Standstill Period, such Affiliate shall, prior to such Affiliate’s acquisition of Shares, agree to be bound by the provisions of this Agreement as a Restricted Party and execute and deliver a Joinder Agreement.

ARTICLE IV—CO-SALE OPTION

Section 4.1. Co-Sale Option . Notwithstanding anything to the contrary in this Agreement, in the event that the Company desires to sell any of its Common Stock for cash at any time during the Class B Period in a transaction that is not registered under the Securities Act in which the Company sells more than 20% of its outstanding Common Stock (calculated after giving effect to such transaction) to a single purchaser (or a single purchaser and its Affiliates considered together) (a “ Co-Sale Transaction ”), the Company shall provide written notice to each Restricted Party that then owns any Applicable Shares (the “ Co-Sale Notice ”) of its right to participate in the Co-Sale Transaction as a seller of Applicable Shares on a pro rata basis with the Company (the “ Co-Sale Option ”) and of the terms and conditions of the Co-Sale Transaction.

Section 4.2. Restricted Party Acceptance . Each of the Restricted Parties receiving the Co-Sale Notice shall have the right to exercise its Co-Sale Option by giving written notice of such intent to participate (the “ Co-Sale Acceptance Notice ”) to the Company within 10 Business Days after receipt by such Restricted Party of the Co-Sale Notice (the “ Co-Sale Election Period ”). Each Co-Sale Acceptance Notice shall indicate the maximum number of Shares subject thereto which the Restricted Party wishes to sell on the terms and conditions set forth in the Co-Sale Notice.

Section 4.3. Allocation of Shares . Each Restricted Party shall have the right to sell the portion of its Applicable Shares pursuant to the Co-Sale Option that is equal to or less than the product obtained by multiplying (a) the total number of Shares proposed to be sold by the Company in the Co-Sale Transaction, as set forth in the Co-Sale Notice, by (b) such Restricted Party’s Ownership Percentage as of the date of the Co-Sale Notice (such product being such Restricted Party’s “ Co-Sale Shares ”). The number of shares that the Company may sell in the Co-Sale Transaction shall be reduced by the aggregate number of Co-Sale Shares to be sold by each Restricted Party that exercised its Co-Sale Option.

Section 4.4. Co-Sale Closing . Within 10 days after the end of the Co-Sale Election Period, the Company shall promptly notify each participating Restricted Party in writing of the number of Shares held by such Restricted Party that will be included in the Co-Sale Transaction and the date on which the Co-Sale Transaction will be consummated, which shall be no later than the later of (i) 45 days after the end of the Co-Sale Election Period and (ii) 10 days after the satisfaction of all stockholder approval and governmental and regulatory approval and filing requirements relating to the Co-Sale Transaction, if any. Each participating Restricted Party may effect its participation in any Transaction Offer hereunder by delivery to the Company for delivery to the

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purchaser(s) of Shares in the Co-Sale Transaction, of one or more instruments or certificates, properly endorsed for transfer, representing the Applicable Shares such Restricted Party elects to sell pursuant thereto. The Company shall provide in the definitive documentation relating to the Co-Sale Transaction that at the time of consummation of the Co-Sale Transaction, the purchaser(s) in the Co-Sale Transaction shall remit directly to each participating Restricted Party that portion of the sale proceeds to which the participating Restricted Party is entitled by reason of its participation with respect thereto.

Section 4.5. Co-Sale Permitted . For purposes of clarity, the parties hereto acknowledge and agree that each Restricted Party may sell Applicable Shares pursuant to the Co-Sale Option notwithstanding any restrictions on Transfer or other provisions of this Agreement to the contrary.

ARTICLE V—PREEMPTIVE RIGHT

Section 5.1. Preemptive Right . The Company agrees that, except as set forth in Section 5.5 below, during the Class B Period, it will not sell or issue in exchange for cash in a capital raising transaction: (a) any shares of capital stock of the Company, (b) securities convertible into or exercisable or exchangeable for capital stock of the Company, or (c) options, warrants or rights carrying any rights to purchase or receive capital stock of the Company (a “ Stock Issuance ”), unless it complies with the procedures set forth in this Article V. In the event that the Company desires to engage in a Stock Issuance, the Company shall provide written notice (the “ Issuance Notice ”) to each of the Restricted Parties that holds Applicable Shares (each, a “ Participating Investor ”) identifying the terms of the proposed Stock Issuance (including without limitation price, manner of payment, number or aggregate principal amount of securities (or a reasonably limited range of prices and numbers or amounts of securities), anticipated closing date, and all other material terms) and offering each Participating Investor the opportunity to purchase its Pro Rata Allotment (as hereinafter defined) of such securities in such Stock Issuance on terms and conditions, including price, not less favorable than those on which the Company sells such securities to a third party or parties in such Stock Issuance as described in the Issuance Notice (the “ Preemptive Right ”).

Section 5.2. Investor Acceptance . Notwithstanding Section 7.3 or anything to the contrary in this Agreement, each Participating Investor shall have the right to exercise its Preemptive Right by giving written notice of its intent to participate (the “ Preemptive Acceptance Notice ”) to the Company within 10 Business Days after the Issuance Notice is delivered to such Participating Investor (the “ Preemptive Election Period ”). Each Preemptive Acceptance Notice shall indicate the maximum number of securities subject thereto which the Participating Investor wishes to purchase in the Stock Issuance and the maximum price at which the Participating Investor would purchase such securities (in the event that a range of prices is included in the Issuance Notice) on the terms and conditions set forth in the Issuance Notice. The Preemptive Acceptance Notice shall constitute a valid, legally binding and enforceable agreement of the Participating Investor to purchase, and the Company to sell, a number of securities equal to the lesser of (i) the maximum number of securities that such Participating Investor agreed to purchase in the Preemptive Acceptance Notice at the lowest price at which the Company sells such securities to any third party in the Stock Issuance and (ii) such Participating Investor’s Pro Rata Allotment at a purchase price per security equal to the lowest price at which the Company sells such securities to any third party in the Stock Issuance (the “ Stock Issuance Price ”); provided that such purchase is conditioned upon and subject to (i) the Company having entered into or entering into, within 30 days after the end of the Preemptive Election Period, a definitive agreement with respect to the Stock Issuance and (ii) the closing of the Stock Issuance at a date no later than the later of (A) 30 days after the definitive agreement relating thereto was executed (or, if later, the end of the Preemptive Election Period) and (B) 10 days after the satisfaction of all stockholder approval and governmental and regulatory approval and filing requirements relating to the Stock Issuance, if any.

Section 5.3. Allocation of Shares . Each Participating Investor shall have the right to purchase a portion of the securities issued in the Stock Issuance which is equal to or less than the product obtained by multiplying (A) the total number of securities issued in the Stock Issuance by (B) such Participating Investor’s Ownership Percentage as of the date of the Issuance Notice (such product being referred to herein as such Participating Investor’s “ Pro Rata Allotment ”).

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Section 5.4. Stock Issuance Closing . At the closing, each Participating Investor shall pay the Stock Issuance Price for the number of securities it is purchasing, in immediately available funds by wire transfer to an account of the Company designated by the Company by notice to such Participating Investor, and the Company will deliver the certificates representing such securities to such Participating Investor. If the Company either has not (i) entered a definitive agreement with respect to the Stock Issuance within 30 days after the end of the Preemptive Election Period, or (ii) closed the Stock Issuance by the later of (A) 30 days after the definitive agreement relating thereto was executed (or, if later, the end of the Preemptive Election Period) and (B) 10 days after the satisfaction of all stockholder approval and governmental and regulatory approval and filing requirements, if any, then the Company must send a new Issuance Notice and again comply with the provisions of this Article V prior to effecting any Stock Issuance.

Section 5.5. Exceptions to Preemptive Rights . Notwithstanding the foregoing, the Preemptive Rights granted under this Section V shall be inapplicable with respect to (i) the issuance of shares of Common Stock, options or other awards pursuant to the Equity Incentive Plans or awards or options granted pursuant to the Equity Incentive Plans; (ii) securities issued as a result of any stock split, stock dividend, reclassification or reorganization or similar event with respect to the Shares; (iii) Shares issued upon conversion or exercise of, or as a dividend on, any securities of the Company; (iv) Common Stock issued in connection with any acquisition, merger, stock exchange or asset acquisition that is approved by the Board of Directors (an “ Acquisition Issuance ”); (v) the issuance of Common Stock to any strategic partner, including without limitation, any supplier or developer of the Company, except to the extent that the number of shares issued pursuant to this clause (v) exceeds 10% of the Shares (on an as converted basis) outstanding immediately following the Closing (as adjusted for future stock splits, reverse stock splits, stock dividends, reclassifications, reorganizations, or similar events); (vi) Common Stock issued to any financial institution or lessor in connection with a lending or leasing transaction approved by the Board of Directors; (vii) Common Stock issued in a public offering by the Company approved by the Board of Directors; and (viii) Common Stock issued in a private offering by the Company approved by the Board of Directors, provided , that the aggregate gross proceeds attributable to sales for the account of the Company in such private offering does not exceed $7,500,000.

ARTICLE VI—TOP UP RIGHTS

Section 6.1. Top Up Right—Large Acquisition Issuance . Notwithstanding Section 7.3 or anything else to the contrary in this Agreement, during the Class B Period, immediately following each Acquisition Issuance with a value equal to or in excess of $7,500,000 (a “ Large Acquisition Issuance ”), each Restricted Party holding Applicable Shares shall have the right, but not the obligation, to purchase from the Company, and the Company shall have the obligation to sell to each such Restricted Party (subject to the closing of the Large Acquisition Issuance), up to that number of shares of Common Stock equal to the “Top Up Shares” as determined by the following formula:

where :

“ Top Up Shares ” means the maximum number of shares of Common Stock that such holder of Applicable Shares is entitled to purchase (and the Company is obligated to sell and issue) pursuant to this Section 6.1;

“ AI Shares ” means the total number of shares of Common Stock issued in the Acquisition Issuance; and

“ OP ” means such Restricted Party’s Ownership Percentage at the date the Company receives its Top Up Exercise Notice.

Section 6.2. Top Up Right—Small Acquisition Issuance . Notwithstanding Section 7.3 or anything else to the contrary in this Agreement, during the Class B Period, immediately following each Acquisition Issuance with

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a value less than $7,5000,000 (a “ Small Acquisition Issuance ”), unless within 5 calendar days following the execution of definitive agreements with respect to such Small Acquisition Issuance, the Company offers each Restricted Party holding Applicable Shares the same Top Up Right with respect to such Small Acquisition Issuance that such holder would have had if such Small Acquisition Issuance was a Large Acquisition Issuance (in which case the procedures applicable to the Top Up Right in Section 6.1 will apply), each Restricted Party holding Applicable Shares shall have the right, but not the obligation (subject to the closing of the Small Acquisition Issuance), to purchase in one or more transactions in the public markets during the three-month period following the closing of such Small Acquisition Issuance, up to an aggregate number of shares of Common Stock equal to the “Top Up Shares” as determined by the following formula:

where :

“ Top Up Shares ” means the maximum number of shares of Common Stock that such holder of Applicable Shares is entitled to purchase pursuant to this Section 6.2;

“ AI Shares ” means the total number of shares of Common Stock issued in the Small Acquisition Issuance; and

“ OP ” means such Restricted Party’s Ownership Percentage at the time the definitive agreement(s) for the Small Acquisition Issuance were executed.

Each Restricted Party that acquires shares of Common Stock as a result of purchases in the public markets pursuant to this Section 6.2 will provide notice to the Company of such purchase within 5 Business Days thereafter and will submit the stock certificate representing such shares to the Company as soon as reasonably practicable for the purpose of reregistering such certificate in the name of such Restricted Party, if not already done, and adding the legend described in Section 8.2(a) to such certificates.

Section 6.3. Exercise of Top Up Right—Acquisition Issuance . The Company shall promptly provide written notification to the holders of Applicable Shares of the closing of any Acquisition Issuance (an “ Acquisition Issuance Notice ”). The failure or refusal of the Company to provide an Acquisition Issuance Notice in accordance with this Section 6.3 shall not limit the rights of any holder of Applicable Shares in any manner whatsoever. A Restricted Party holding Applicable Shares shall notify the Company in writing of the exercise of its Top Up Right (a “ Top Up Exercise Notice ”) within 10 days after its receipt of an Acquisition Issuance Notice relating to a Large Acquisition Issuance.

Section 6.4. Top-Up Right—Equity Incentive Plans . On or before January 20 ^th of each year (each, a “ Notice Date ”) during the period from the Closing Date until the earlier of (a) the end of the Class B Period or (b) the end of the 5-Year Standstill Period (the “ Top Up Period ”), the Company shall provide to each Restricted Party holding Applicable Shares a notice disclosing the number of shares of Common Stock issued by the Company pursuant to the Equity Incentive Plans, by stock option exercise or otherwise, in the preceding calendar year, less (x) any shares reacquired by the Company during such year as payment of the exercise price of a stock option or the tax withholding obligation in connection with any award under an Equity Incentive Plan, (y) any shares of unvested restricted stock originally issued pursuant to an Equity Incentive Plan that are forfeited or repurchased by the Company during such year, and (z) any shares otherwise reacquired by the Company as permitted under an Equity Incentive Plan during such year (such number, less the items described in clauses (x), (y) and (z), being referred to as the “ EIP Shares ” for such year); provided , however , that the EIP Shares for the calendar year ended December 31, 2006 shall equal the number of shares of Common Stock issued by the Company pursuant to the Equity Incentive Plans for the period beginning on the Closing Date and ending on December 31, 2006, net of (x) any shares reacquired by the Company during such period as payment of the exercise price of a stock option or the tax withholding obligation in connection with any award under an Equity

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Incentive Plan, (y) any shares of unvested restricted stock originally issued pursuant to an Equity Incentive Plan that are forfeited or repurchased by the Company during such period, and (z) any shares otherwise reacquired by the Company as permitted under an Equity Incentive Plan during such period.

Notwithstanding Section 7.3 or anything else to the contrary in this Agreement, during the Top Up Period each Restricted Party holding Applicable Shares shall have the right, but not the obligation, to purchase in one or more transactions in the public markets during the three-month period beginning on the February 1 ^st immediately following the relevant Notice Date, up to an aggregate number of shares of Common Stock equal to the “Top Up Shares” for the prior year as determined by the following formula:

where :

“ Top Up Shares ,” for a specified year, means the maximum number of shares of Common Stock that such holder of Applicable Shares is entitled to purchase pursuant to this Section 6.4;

“ EIP Shares ,” for a specified year, has the meaning set forth above; and

“ OP ” means such Restricted Party’s Ownership Percentage as of the Notice Date.

Each Restricted Party that acquires shares of Common Stock as a result of purchases in the public markets pursuant to this Section 6.4 will provide notice to the Company of such purchase within 5 Business Days thereafter and will submit the stock certificate representing such shares to the Company as soon as reasonably practicable for the purpose of reregistering such certificate in the name of such Restricted Party, if not already done, and adding the legend described in Section 8.2(a) to such certificates.

The rights described in Sections 6.1 and 6.2 hereof and this Section 6.4 are sometimes referred to herein collectively as a “ Top Up Right .”

Section 6.5. Issuance of Common Stock . The issuance of Common Stock by the Company pursuant to a Top Up Right in connection with an Acquisition Issuance, shall occur within 10 days after, and be subject to, the closing of such Acquisition Issuance.

Section 6.6. Purchase Price . The per-share purchase price for the Common Stock issued by the Company pursuant to a Top Up Right in connection with an Acquisition Issuance shall be equal to the implied per-share value paid by the counterparty in the Acquisition Issuance; provided , however , that if such per-share value is not set forth or otherwise determinable from the definitive documentation relating to the Acquisition Issuance, then the per-share purchase price shall be equal to the average closing price of the Common Stock as reported by NASDAQ during the 30 consecutive trading days immediately preceding the execution of such definitive documentation.

Section 6.7. Stockholder Approval . In the event that the Board of Directors determines (after consultation with counsel) that the issuance of shares of Common Stock by the Company pursuant to the Top Up Right in connection with an Acquisition Issuance would (i) cause an Acquisition Issuance not otherwise subject to approval by the stockholders of the Company to be subject to approval by the stockholders of the Company under NASD Rule 4350 or any other NASD rule or applicable law, and/or (ii) require an amendment of the Charter to increase the number of authorized shares of Common Stock, then, as a condition to the issuance of shares pursuant to the Top Up Right, each Person issuing a Top Up Exercise Notice shall vote all of its Applicable Shares in favor of the Acquisition Issuance and/or the amendment of the Certificate of Incorporation, as the case may be, and the issuance of its Top Up Exercise Notice shall constitute the grant to the Chief

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Executive Officer, Chief Financial Officer and General Counsel of the Company of an irrevocable proxy, coupled with an interest, to vote such Applicable Shares solely in favor of the foregoing matters accordance with this Section 6.7, but not with respect to any other matter.

ARTICLE VII—COVENANTS OF THE PARTIES

Section 7.1. Covenants of the Company . From and after the date hereof and until the 2 ^nd anniversary of the Closing Date, except as may be required by the terms of the Charter, the Company’s By-Laws or this Agreement, (in which case the Company shall provide not less than 30 days written notice to the Restricted Parties holding Applicable Shares prior to any such action by the Company), without the prior written consent of the Restricted Parties holding Applicable Shares, the Company shall not:

(a) redeem or repurchase any Shares, except (i) as the purchase price for any stock option or warrant, (ii) as permitted or required under any Equity Incentive Plan or any option or award outstanding under any Equity Incentive Plan, including, without limitation, as the payment of the exercise price of a stock option or the tax withholding obligation in connection therewith using Company equity securities, the Company’s repurchase of unvested restricted stock or otherwise, or (iii) ROFO Shares from Transferring Investors pursuant to Section 3.4 hereof;

(b) pay any dividend or distribution (other than a liquidating distribution or a dividend or distribution of common or preferred stock purchase rights in connection with the adoption of a “poison pill” shareholder rights agreement approved by the Board of Directors) with respect to shares of the Company’s capital stock; or

(c) enter into any binding agreement to take any of the actions discussed in (a) and (b) above.

Section 7.2. Covenants of the Restricted Parties . During the Class B Period, each of the Restricted Parties, individually and not jointly, agrees as follows:

(a) to vote all Applicable Shares held by such Restricted Party and all Applicable Shares over which such Restricted Party exercises voting control whether directly or indirectly, for all director nominees recommended by the Board of Directors and to withhold from any other directors nominees; and

(b) to be present, in person or by proxy, at all meetings of the stockholders of the Company with respect to all Applicable Shares held by such Restricted Party and all Applicable Shares over which such Restricted Party exercises voting control, whether directly or indirectly.

If a Restricted Party fails or refuses to vote such the Applicable Shares held or controlled by such Restricted Party as required by, or votes such Applicable Shares in contravention of this Section 7.2, then such Restricted Party hereby grants to the Chief Executive Officer, Chief Financial Officer and General Counsel of the Company an irrevocable proxy, coupled with an interest, to vote such Applicable Shares solely in accordance with Section 7.2(a), but not with respect to any other matter.

Section 7.3. Standstill Covenants of the Restricted Parties . Except as otherwise provided in Article V and Article VI and Section 7.4 below of this Agreement or with the Company’s prior, written consent, during the 5-Year Standstill Period, none of the Restricted Parties nor any Non-Party Investor Affiliate, acting alone or as part of any group (within the meaning of section 13(d)(3) of the Exchange Act), directly or indirectly, shall:

(a) acquire or agree, offer, seek or propose to acquire, or cause to be acquired, ownership (including, but not limited to, beneficial ownership as defined in Rule 13d-1 under the Exchange Act) of any of the assets or businesses of the Company or any of its subsidiaries or of any Common Stock or other securities of the Company or any of its subsidiaries, or any rights or options to acquire any such ownership (including from a third party), except for Transfers of Shares permitted by this Agreement;

(b) make, or in any way participate in, any “solicitation” of “proxies” (as such terms are used in the Exchange Act) to vote or seek to advise or influence in any manner whatsoever any person or entity (other than a Restricted Party) with respect to the voting of any securities of the Company or any of its subsidiaries;

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(c) form, join, or in any way participate in a “group” (within the meaning of section 13(d)(3) of the Exchange Act) (other than a group consisting of only Restricted Parties and their Affiliates ) with respect to any voting securities of the Company or any of its subsidiaries;

(d) arrange, or in any way participate in, any financing for the purchase of any voting securities or securities convertible or exchangeable into or exercisable for any voting securities or assets of the Company or any of its subsidiaries other than in connection with Transfers permitted by this Agreement;

(e) otherwise act, whether alone or in concert with others, to seek to propose to the Company or any of its stockholders any merger, business combination, tender or exchange offer, restructuring, recapitalization, liquidation of or similar transaction with or involving the Company or any of its subsidiaries or otherwise intentionally act, whether alone or in concert with others, to seek to control, change or influence the management, Board of Directors or policies of the Company, or nominate any person as a Director of the Company, or propose any matter to be voted upon by the stockholders of the Company, except through the appointment of Class B Directors and through the exercise of rights under this Agreement, the Stock Purchase Agreement and the Certificate of Designations;

(f) solicit, negotiate with, or provide any information to, any person with respect to a merger, business combination, tender or exchange offer, restructuring, recapitalization, liquidation of or similar transaction with or involving the Company or any of its subsidiaries or any other acquisition of the Company or any of its subsidiaries, any acquisition of voting securities of or all or any portion of the assets of the Company or any of its subsidiaries, or any other similar transaction;

(g) announce an intention to, or enter into any discussions, negotiations, arrangements or understandings with any third party with respect to, any of the foregoing;

(h) publicly disclose any intention, plan or arrangement inconsistent with the foregoing; or

(i) intentionally or knowingly provide any advice or assistance to any other Person other than a Restricted Party or Affiliate thereof in connection with any of the foregoing.

Section 7.4. Sale of the Company .

(a) Notwithstanding the restrictions in Section 7.3 or anything else to the contrary in this Agreement, if the Company initiates any process to sell substantially all of the assets of the Company, whether by way or merger or consolidation, stock purchase, asset sale or otherwise (each of the events described in this subsection, a “ Sale Transaction ”) at any time during the 5-Year Standstill Period when the Restricted Parties collectively own at least 10% of the Shares then outstanding (on an as-converted basis), then, the Restricted Parties shall be entitled to participate as a bidder in such process to the same extent and on the same basis as the Company generally permits other third parties to participate and to take actions incidental thereto.

(b) Notwithstanding the restrictions in Section 7.3 or anything else to the contrary in this Agreement, if the Company receives an unsolicited proposal to enter into a Sale Transaction at any time during the 5-Year Standstill Period when the Restricted Parties collectively own at least 10% of the Shares then outstanding (on an as-converted basis), then at least 12 Business Days prior to the approval of the Board of Directors of any definitive agreement relating to such unsolicited proposal, the Company shall notify the Restricted Parties in writing of such unsolicited proposal and the terms thereof and the Restricted Parties shall have the right to submit to the Board of Directors, within 10 Business Days after the Company provides such notice, a proposal to enter into a Sale Transaction with the Company, which proposal the Board of Directors shall consider in good faith. If the Board of Directors does not approve an unsolicited proposal described herein then the Company will not be required to permit any Restricted Party to submit a proposal to enter into a Sale Transaction. Notwithstanding the foregoing, this Section 7.4(b) shall not apply with respect to an unsolicited proposal to enter into a Sale Transaction at any time from and after the date on which the Company initiates a process to enter into a Sale Transaction and, in connection therewith, complies with the provisions of Section 7.4(a) above.

Section 7.5. Non-Party Investor Affiliate Breach of Standstill . In addition to any other legal or equitable remedies which the Company may have and the right to enforce the provisions of this Agreement by actions for

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specific performance (to the extent permitted by applicable law), in the event a Non-Party Investor Affiliate, acting alone or as part of any group (within the meaning of section 13(d)(3) of the Exchange Act), directly or indirectly during the 5-Year Standstill Period:

(a) acquires or agrees, offers, seeks or proposes to acquire, or causes to be acquired, ownership of any Common Stock or other securities of the Company in a manner that would have constituted a breach of the provisions of this Agreement if such Non-Party Investor Affiliate had been a party to this Agreement as a Restricted Party, then, the Company shall have the right to demand that the Restricted Parties, and the Restricted Parties shall be required to, convert shares of Class B Capital Stock convertible, in the aggregate, into an equal number of shares of Common Stock and to vote such shares of Common Stock as directed by the Board of Directors on all matters until the termination of the 5-Year Standstill Period.

(b) submits a director nominee or shareholder proposal with respect to any voting securities of the Company held or controlled by such Non-Party Investor Affiliate, in a manner that would have constituted a breach of the provisions of this Agreement if such Non-Party Investor Affiliate had been a party to this Agreement, then, the Restricted Parties will vote all voting securities of the Company beneficially owned by such Restricted Parties against (withhold vote from) any such director nominee and against any such shareholder proposal.

(c) commences a “tender offer” (as such term in used in the Exchange Act) or exchange offer for any Shares of the Company, then, the Restricted Parties will not tender or exchange any securities of the Company beneficially owned by them unless the Board of Directors recommends that all of the Company’s stockholders do so.

Section 7.6. Termination of NDAs .

(a) All of the provisions of the Company NDA (including without limitation the standstill provisions under section 6 thereof) other than the confidentiality provisions under sections 1 and 2 thereof, shall terminate effective as of the Closing Date.

(b) All of the provisions of the Buyer NDA other than the confidentiality provisions under sections 1, 2, 3 and 4 thereof, shall terminate effective as of the Closing Date.

(c) All confidentiality provisions under sections 1 and 2 of the Company NDA and sections 1, 2, 3, and 4 of the Buyer NDA shall terminate upon the second anniversary of the Closing Date.

ARTICLE VIII—MISCELLANEOUS PROVISIONS

Section 8.1. Survival of Covenants . Each of the parties hereto agrees that each covenant and agreement made by it in this Agreement or in any certificate, instrument or other document delivered pursuant to this Agreement is material, shall be deemed to have been relied upon by the other parties and shall remain operative and in full force and effect after the date hereof regardless of any investigation. This Agreement shall not be construed so as to confer any right or benefit upon any Person other than the parties hereto (and future parties hereto) and their respective successors, heirs, and Permitted Transferees.

Section 8.2. Legends on Securities .

(a) The Company and the Restricted Parties acknowledge and agree that in addition to any other legend on the certificates representing Shares held by them, substantially the following legend shall be typed on each certificate evidencing any of the Shares held at any time by any of the Restricted Parties:

THE SECURITIES REPRESENTED HEREBY ARE SUBJECT TO THE PROVISIONS OF A CERTAIN INVESTOR RIGHTS AGREEMENT, DATED AS OF JUNE 29, 2006, INCLUDING CERTAIN RESTRICTIONS ON TRANSFER SET FORTH THEREIN. A COMPLETE AND CORRECT COPY OF SUCH AGREEMENT IS AVAILABLE FOR INSPECTION AT THE PRINCIPAL OFFICE OF THE COMPANY AND WILL BE FURNISHED UPON WRITTEN REQUEST AND WITHOUT CHARGE.

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(b) Additionally, each certificate representing Class B Shares shall, except as otherwise provided in this Section 8.2, be stamped or otherwise imprinted with a legend substantially in the following form:

THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 OR ANY STATE SECURITIES LAWS AND MAY NOT BE TRANSFERRED OR OTHERWISE DISPOSED OF UNLESS IT HAS BEEN REGISTERED UNDER SUCH ACT AND ALL SUCH APPLICABLE LAWS OR AN EXEMPTION FROM REGISTRATION IS AVAILABLE.

A certificate shall not bear such legend if in the opinion of counsel satisfactory to the Company the securities represented thereby may be publicly sold without registration under the Securities Act and any applicable state securities laws.

(c) Prior to any proposed Transfer of any Class B Shares during the 5-Year Standstill Period, the holder thereof shall give written notice to the Company of its intention to effect such Transfer. Each such notice shall describe the manner of the proposed Transfer, whereupon, if permitted under this Agreement, the holder of such stock shall be entitled to Transfer such stock in accordance with the terms of its notice and the terms of this Agreement, if applicable. Each certificate for any Class B Shares, Transferred as above provided shall bear the legend set forth in Section 8.2(b), except that such certificate shall not bear such legend if (i) such Transfer is in accordance with the provisions of Rule 144 (or any other rule permitting public sale without registration under the Securities Act), (ii) such Transfer is registered under the Securities Act or (iii) the Transferor shall provide an opinion of counsel satisfactory to the Company to the effect that the Transferee and any subsequent Transferee (other than an affiliate of the Company) would be entitled to Transfer such securities in a public sale without registration under the Securities Act.

Section 8.3. Amendment and Waiver . Any party hereto may waive any provision hereof intended for its benefit in writing. No failure or delay on the part of any party hereto in exercising any right, power or remedy hereunder shall operate as a waiver thereof. The remedies provided for herein are cumulative and are not exclusive of any remedies that may be available to any party hereto at law or in equity or otherwise. This Agreement may not be amended except with the prior written consent of the Company and Restricted Parties holding a majority of the Applicable Shares at such time. Any consent given as provided in the preceding sentence shall be binding on the Company and all Restricted Parties.

Section 8.4. Notices . All notices, requests, consents and other communications hereunder shall be in writing, in English, shall be delivered (A) if within the United States, by first-class registered or certified airmail, or nationally recognized overnight express courier, postage prepaid, or by facsimile, or (B) if to or from outside the United States, by a recognized international express courier service or facsimile, and shall be deemed given (i) if delivered by first-class registered or certified mail domestic, upon the Business Day received; (ii) if delivered by nationally recognized overnight carrier, one (1) Business Day after timely delivery to such carrier; (iii) if delivered by a recognized international express courier service, two (2) Business Days after timely delivery to such carrier; (iv) if delivered by facsimile, upon electric confirmation of receipt and shall be addressed as follows, or to such other address or addresses as may have been furnished in writing by a party to another party pursuant to this Section 8.4:

if to the Company, to:

Plug Power Inc.

968 Albany-Shaker Road

Latham, New York 12110

Attention: General Counsel

Facsimile: (518) 782-7884

with a copy (which shall not constitute notice) to:

Goodwin Procter LLP

Exchange Place

Boston, Massachusetts 02109

Attention: Robert P. Whalen, Jr.

Facsimile: (617) 523-1231

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if to a Restricted Party, to:

Smart Hydrogen Inc.

c/o Interros Holding Company

9, Bolshaya Yakimanka Street

119180 Moscow

Russian Federation

Attn: Marianna Zakharova

Facsimile: 7-495-785-6362

with a copy (which shall not constitute notice) to:

Baker Botts L.L.P.

The Warner

1299 Pennsylvania Avenue, N.W.

Washington, DC 20004-2400

Attention: Gregory J. Golden

Facsimile: (202) 585-1025

In the event of a Person joins this Agreement as a Restricted Party after the date hereof, notices given pursuant to this Agreement to such Restricted Party shall be delivered to the relevant address specified in the relevant agreement in the form of Exhibit A whereby such Restricted Party became bound by the provisions of this Agreement.

Section 8.5. Headings . The Article and Section headings used or contained in this Agreement are for convenience of reference only and shall not affect the construction of this Agreement. The parties have participated jointly in the negotiation and drafting of this Agreement and the other agreements, documents and instruments executed and delivered in connection herewith with counsel sophisticated in investment transactions. In the event an ambiguity or question of intent or interpretation arises, this Agreement and the agreements, documents and instruments executed and delivered in connection herewith shall be construed as if drafted jointly by the parties and no presumption or burden of proof shall arise favoring or disfavoring any party by virtue of the authorship of any provisions of this Agreement and the agreements, documents and instruments executed and delivered in connection herewith.

Section 8.6. Counterparts . This Agreement may be executed in one or more counterparts and by the parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which together shall be deemed to constitute one and the same agreement.

Section 8.7. Remedies; Severability . It is specifically understood and agreed that any breach of the provisions of this Agreement by any Person subject hereto will result in irreparable injury to the other parties hereto, that the remedy at law alone will be an inadequate remedy for such breach, and that, in addition to any other legal or equitable remedies which they may have, such other parties may enforce their respective rights by actions for specific performance (to the extent permitted by applicable law) and the Company may refuse to recognize any Transferee of Shares Transferred in violation of this Agreement as one of its stockholders for any purpose, including, without limitation, for purposes of dividend and voting rights, until the relevant party or parties have complied with all applicable provisions of this Agreement.

In the event that any one or more of the provisions contained herein, or the application thereof in any circumstances, is held invalid, illegal or unenforceable in any respect for any reason, the validity, legality and enforceability of any such provision in every other respect and of the remaining provisions contained herein shall not be in any way impaired thereby, it being intended that all of the rights and privileges of the parties hereto shall be enforceable to the fullest extent permitted by law.

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Section 8.8. Entire Agreement . This Agreement, the Registration Rights Agreement and the Stock Purchase Agreement are intended by the parties as a final expression of their agreement and intended to be complete and exclusive statement of the agreement and understanding of the parties hereto in respect of the subject matter contained herein.

Section 8.9. Law Governing . This Agreement shall be construed and enforced in accordance with and governed by the laws of the State of New York (without giving effect to principles of conflicts of law).

Section 8.10. Successors and Assigns . This Agreement shall be binding upon and inure to the benefit of the parties hereto and their respective successors, heirs, and permitted assigns and to Permitted Transferees of the parties hereto as contemplated herein. Any successor to the Company by way of merger or otherwise shall specifically agree to be bound by the terms hereof as a condition of such succession. Neither this Agreement nor any of the rights contained herein may be assigned by any Restricted Party except as provided herein without the prior written consent of the Company. Neither this Agreement nor any of the rights or obligations contained herein may be assigned or delegated by the Company without the prior written consent of the Restricted Parties holding a majority of the Applicable Shares at such time.

Section 8.11. Dispute Resolution .

(a) The parties to this Agreement shall endeavor to resolve any dispute, claim, or controversy arising out of or relating to this Agreement (including, but not limited to, the negotiation, validity, performance breach or termination thereof) (each, a “ Dispute ”) by non-binding mediation under the CPR Mediation Procedure then currently in effect. The mediator will be selected upon mutual agreement of the parties engaged in the Dispute (the “ Disputing Parties ”). Any Dispute which remains unresolved 30 days after the appointment of a mediator (or if the Disputing Parties are unable to agree upon a mediator within 30 days after a Disputing Party notifies another Disputing Party of a Dispute in writing), shall be finally resolved by arbitration in accordance with the CPR Rules for Non-Administered Arbitration, Revised and Effective June 15, 2005 (the “ Rules ”). A tribunal of three arbitrators will preside over any Dispute(s) (the “ Tribunal ”). Each Disputing Party shall appoint one arbitrator to the Tribunal or, if there are more than two Disputing Parties and the Company is one of the Disputing Parties, then the Company shall appoint one arbitrator and the other Disputing Parties shall jointly appoint one arbitrator. Within 30 days of the appointment of the second arbitrator, the two arbitrators appointed by the Disputing Parties shall appoint a third arbitrator, who shall chair the Tribunal (the “ Chairperson ”). In the event the arbitrators appointed by the Disputing Parties are unable to agree on the Chairperson, the Chairperson will be selected as provided in Rule 6 of the Rules. Under no circumstances shall the Chairperson be either an American or Russian citizen. The place of arbitration shall be New York, New York and the language of the arbitration shall be English. Upon the request of any Disputing Party, there shall be simultaneous translation of all communications with the Tribunal into English or Russian, as the case may be. The arbitration shall be governed by the Federal Arbitration Act, 9 U.S.C. §§ 1-16, and judgment upon or other enforcement of the award rendered by the Tribunal may be entered by the U.S. District Court for the Southern District of New York.

(b) Unless otherwise agreed by the Disputing Parties, the Tribunal’s decision and award shall be made and delivered within 30 days of the conclusion of the arbitration. The parties acknowledge that the Tribunal shall have the authority, with respect to any Dispute, to provide any and all relief, whether legal, equitable, or otherwise, and award any damages or remedy that a federal court in New York could provide or award with respect to such Dispute. The Tribunal shall have no jurisdiction, power, or authority to decide or award punitive or exemplary damages. It is the expressed intention of the parties hereto to mutually waive the right to seek or recover such damages from the other.

(c) The parties covenant and agree that they will share equally the costs of an arbitration pursuant to this Section 8.11, except as otherwise provided herein. The Tribunal may in its discretion assess costs and expenses (including the reasonable legal fees and expenses of the prevailing party) against any Disputing Party to a proceeding. Any Disputing Party unsuccessfully refusing to comply with an award of the Tribunal shall be liable for costs and expenses, including reasonable attorneys’ fees, incurred by any other Disputing Party in enforcing the award.

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(d) Each party irrevocably waives any objection to proceeding before the Tribunal in New York, to the extent provided in this Section 8.11, based upon lack of personal jurisdiction or to the laying of venue and further irrevocably and unconditionally waives and agrees not to make a claim that arbitration in accordance with these provisions has been brought in an inconvenient forum. Each of the parties hereto hereby consents to service of notice for any arbitration pursuant to this Section 8.11 as provided for in Rule 2 of the Rules.

(e) Notwithstanding the foregoing, the parties hereby consent to the sole and exclusive jurisdiction of the U.S. District Court for the Southern District of New York for any action, suit or proceeding to compel arbitration pursuant to this Section 8.11, seek a preliminary injunction or other provisional judicial relief in aid of arbitration with respect to any Dispute, or obtain judgment upon or other enforcement of any award or decision rendered by the Tribunal pursuant to this Section 8.11, and the parties agree that the foregoing provisions requiring non-binding mediation and arbitration of Disputes shall not apply to any such action, suit, or proceeding. The parties further hereby irrevocably and unconditionally waive any objection to the laying of venue of any such action, suit, or proceeding in the United States District Court for the Southern District of New York and hereby further irrevocably and unconditionally waive and agree not to plead or claim in such court that any such action, suit, or proceeding brought in such court has been brought in an inconvenient forum. Each of the parties further agrees that service of any process, summons, notice, or document by U.S. registered mail (with respect to any address in the United States) or by a recognized international express courier service, including, without limitation, International Federal Express (with respect to any address outside of the United States) to such party’s then current address for notice pursuant to Section 8.4 shall be effective service of process for any action, suit, or proceeding brought against it in such court. Each of the parties hereto agrees that its or his submission to jurisdiction and its or his consent to service of process in the manner described above is made for the express benefit of the other parties hereto.

(f) The procedures specified in this Section 8.11 shall be the sole and exclusive procedures for the resolution of Disputes.

[SIGNATURE PAGE FOLLOWS]

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IN WITNESS WHEREOF, the parties hereto have caused this Restricted Party Rights Agreement to be duly executed as of the date first set forth above.

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EXHIBIT A

Form of Joinder Agreement

The undersigned (the “Transferee”) hereby agrees, effective as of the date hereof and upon the countersignature of Plug Power Inc. (the “Company”), to become a party to, and be bound by all the terms and conditions (including, without limitation, the dispute resolutions provisions contained in Section 8.11) of, that certain Investor Rights Agreement (the “Agreement”) dated as of June 29, 2006, by and among Company and the parties named therein as a Restricted Party and for all purposes of the Agreement, the undersigned shall be included within the term “Restricted Party” (as defined in the Agreement). The undersigned further confirms that the representations and warranties contained in Section II of the Agreement are true and correct as to the undersigned as of the date hereof. The address and facsimile number to which notices may be sent to the undersigned is as follows:

Address For Notice:

Facsimile No.:

Accepted and agreed by the Company as of the date written above. The Company hereby makes the representations and warranties set forth in Section 2.2 of the Agreement to the Transferee as of the date hereof.

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Exhibit 99.2

F ORM OF R EGISTRATION R IGHTS A GREEMENT

This REGISTRATION RIGHTS AGREEMENT (this “ Agreement ”) is made as of June 29, 2006 by and between Plug Power Inc., a Delaware corporation (the “ Company ”), and Smart Hydrogen Inc., a BVI Business Company incorporated under the laws of the British Virgin Islands (“ Initial Holder ”), each of which is sometimes referred to herein as a “ Party ” and collectively as the “ Parties .”

RECITALS

WHEREAS, pursuant to that certain Stock Purchase Agreement dated as of April 10, 2006, by and between the Company and Initial Holder (the “ Stock Purchase Agreement ”), Initial Holder shall acquire shares (the “Shares ”) of the Company’s Class B Capital Stock, a series of preferred stock, $0.01 par value per share (“ Class B Capital Stock ”); and

WHEREAS, in connection with Initial Holder’s investment pursuant to the Stock Purchase Agreement, the Company agreed to provide certain rights to Initial Holder to cause the resale of the shares of Common Stock of the Company, $.01 par value per share (the “ Common Stock ”), issuable upon conversion of the Shares to be registered pursuant to the Securities Act (as defined below); and

WHEREAS, the Parties desire to set forth their rights and obligations relating to the registration of the resale of the Registrable Securities (as defined below) pursuant to the Securities Act;

AGREEMENT

NOW, THEREFORE, in consideration of the purchase of the Shares by Initial Holder pursuant to the Stock Purchase Agreement, and for other good consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties, intending to be legally bound, hereby agree as follows:

1. Definitions . As used in this Agreement the following capitalized terms shall have the following meanings. Capitalized terms used and not defined herein shall have the respective meanings ascribed to them in the Stock Purchase Agreement:

“ Affiliate ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Agreement ” shall have the meaning set forth in the recitals to this Agreement.

“ Business Day ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Chairperson ” shall have the meaning set forth in Section 23.1 hereof.

“ Charter ” shall mean the Company’s Amended and Restated Certificate of Incorporation in effect as of the date hereof, including the Certificate of Designations creating the Class B Capital Stock, as amended from time to time.

“ Class B Capital Stock ” shall have the meaning set forth in the recitals of this Agreement.

“ Class B Period ” shall have the meaning set forth in the Charter.

“ Common Stock ” shall have the meaning set forth in the recitals of this Agreement.

“ Company ” shall have the meaning set forth in the recitals of this Agreement.

“ Company Offering ” shall have the meaning set forth in Section 4.4 hereof.

“ Dispute ” shall have the meaning set forth in Section 23.1 hereof.

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“ Disputing Party ” shall have the meaning set forth in Section 23.1 hereof.

“ Effectiveness Period ” shall mean the period of time commencing on the Resale Shelf Date and ending on the Termination Date.

“ Exchange Act ” shall mean the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder.

“ Fair Market Value ” shall mean the average of the per share closing price, or the closing sales bid if no sales were reported, of the Common Stock as quoted by the NASDAQ National Market for the ten (10) consecutive trading days immediately preceding the date of calculation or if there are no sales or bids for such date, then the average of the ten (10) preceding consecutive trading days for such sales or bids as reported in The Wall Street Journal or similar publication.

“ Holder ” shall mean Initial Holder and any subsequent transferee of Registrable Securities as permitted by Section 10 , at such times as such Persons shall own Registrable Securities.

“ Indemnitee ” shall have the meaning set forth in Section 9 hereof.

“ Initial Holder ” shall have the meaning assigned to such term in the first paragraph of this Agreement.

“ Initiating Holders ” shall have the meaning set forth in Section 3.1 hereof.

“ Investor Rights Agreement ” shall mean that certain Investor Rights Agreement, dated as of the date hereof, by and among the Company, the Initial Holder and certain Affiliates of the Initial Holder named therein.

“ NASD ” shall mean the National Association of Securities Dealers, Inc.

“ NASDAQ ” shall mean the National Association of Securities Dealers Automated Quotations.

“ Non-Initiating Holders ” shall have the meaning set forth in Section 3.1 hereof.

“ Offering Blackout Period ” shall have the meaning set forth in Section 4.4 hereof.

“ Person ” shall have the meaning set forth in the Stock Purchase Agreement.

“ Prior Registrable Securities ” shall have the meaning set forth in Section 3.7 hereof.

“ Prospectus ” shall mean the prospectus included in a Registration Statement, including any preliminary prospectus, as amended or supplemented by any prospectus supplement with respect to the terms of the offering of any portion of the Registrable Securities covered by such Registration Statement, and by all other amendments and supplements to such prospectus, including post-effective amendments, and in each case including all material incorporated by reference therein and excluding all “free writing prospectuses” as defined in Rule 405 of the Securities Act.

“ Registrable Securities ” shall mean all shares of Common Stock issued or issuable upon conversion of the Shares and any shares of Common Stock or other securities issued or issuable in respect of Registrable Securities by way of spin-off, dividend, distribution, stock split or in connection with a combination of shares, reclassification, merger, consolidation or reorganization; provided , however , that Registrable Securities shall not include (i) any securities for which a Registration Statement relating to the sale thereof has become effective under the Securities Act and which have been disposed of under such Registration Statement, (ii) any securities sold pursuant to Rule 144, or (iii) any securities held by a person whose registration rights pursuant to this Agreement have terminated pursuant to Section 7 .

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“ Registration Expenses ” shall mean any and all expenses incident to the performance of or compliance with this Agreement, including without limitation: (a) all registration, federal and state filing, and qualification fees and expenses; (b) all fees and expenses associated with a required listing of the Registrable Securities on any securities exchange; (c) fees and expenses with respect to filings required to be made with the NASDAQ or the NASD; (d) fees and expenses of compliance with securities or “blue sky” laws (including reasonable fees and disbursements of counsel for the underwriters or holders of securities in connection with blue sky qualifications of the securities and determination of their eligibility for investment under the laws of such jurisdictions); (e) printing expenses, messenger, telephone and delivery expenses; (f) fees and disbursements of counsel for the Company and customary fees and expenses for independent certified public accountants retained by the Company (including the expenses of any comfort letters, or costs associated with the delivery by independent certified public accountants of a comfort letter or comfort letters, if such comfort letter or comfort letters is required by the managing underwriter); and (g) the fees and expenses of any Person, including special experts, retained by the Company; provided , however , that Registration Expenses shall not include any underwriting fees, discounts, or commissions attributable to the sale of such Registrable Securities, or any legal fees and expenses of counsel to any Holder and any underwriter engaged in connection with an Underwritten Demand Statement.

“ Registration Statement ” shall mean any registration statement of the Company which covers the resale of any of the Registrable Securities under the Securities Act on an appropriate form, and all amendments and supplements to such registration statement, including post-effective amendments, in each case including the Prospectus contained therein, all exhibits thereto and all materials incorporated by reference.

“ Resale Shelf Date ” shall have the meaning set forth in Section 2.1 hereof.

“ Resale Shelf Registration Statement ” shall have the meaning set forth in Section 2.1 hereof.

“ Rule 144 ” means Rule 144 under the Securities Act (or any successor provision).

“ Rules ” shall have the meaning set forth in Section 23.1 hereof.

“ SEC ” shall mean the United States Securities and Exchange Commission.

“ Securities Act ” shall mean the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.

“ Selling Holder ” shall mean, with respect to a specified Registration Statement pursuant to this Agreement, Holders whose Registrable Securities are included in such registration.

“ Shares ” shall have the meaning set forth in the recitals of this Agreement.

“ Suspension Event ” shall have the meaning set forth in Section 4.3 hereof.

“ Suspension Event Certificate ” shall have the meaning set forth in Section 4.3 hereof.

“ Termination Date ” shall mean the earlier of (a) the date on which the registration rights of all Persons pursuant to this Agreement have terminated pursuant to Section 7 or (b) the date the Company is acquired in a transaction approved by the Company’s Board of Directors (including, without limitation, through a merger, consolidation, stock purchase, or sale of all or substantially all of the Company’s assets).

“ Tribunal ” shall have the meaning set forth in Section 23.1 hereof.

“ Underwritten Demand Notice ” shall have the meaning set forth in Section 3.1 hereof.

“ Underwritten Demand Shares ” shall have the meaning set forth in Section 3.1 hereof.

“ Underwritten Demand Statement ” shall have the meaning set forth in Section 3.1 hereof.

“ WKSI ” shall mean a well-known seasoned issuer as defined under Rule 405 of the Securities Act.

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2. Resale Shelf Registration Rights .

2.1 Registration Statement Covering Resale of Registrable Securities . Prior to date that is eighteen (18) months after the Closing Date (the “ Resale Shelf Date ”), the Company shall file with the SEC a shelf registration statement on Form S-3 pursuant to Rule 415 under the Securities Act covering all of the Registrable Securities registering the resale on a delayed or continuous basis of all such Registrable Securities by the Holders (a “ Resale Shelf Registration Statement ”). The Resale Shelf Registration Statement shall be filed on Form S-3, and if the Company is eligible as a WKSI, the Resale Shelf Registration Statement shall utilize the automatic shelf registration process under Rule 415 and Rule 462 under the Securities Act. If the Company is not a WKSI or is otherwise ineligible to utilize the automatic shelf registration process, then the Company shall use its commercially reasonable efforts to have the Resale Shelf Registration Statement declared effective under the Securities Act prior to the Resale Shelf Date and as expeditiously as reasonably practicable following the filing of the Resale Shelf Registration Statement. The Company agrees to use its commercially reasonable efforts to maintain the effectiveness of the Resale Shelf Registration Statement, including by filing any necessary post-effective amendments and prospectus supplements during the Effectiveness Period; provided that the effectiveness of the Resale Shelf Registration Statement need not be maintained for the purposes of registering the resale of securities that no longer constitute Registrable Securities or at any time when the Company is not eligible to file a registration statement on Form S-3 (or any similar or successor form) for the purpose of registering the resale of the Registrable Securities. If, during the Effectiveness Period, the Company becomes eligible to file a registration statement on Form S-3 (or any similar or successor form) for the purpose of registering the resale of the Registrable Securities at any time when a Resale Shelf Registration Statement is not effective, the Company, shall promptly file a Resale Shelf Registration Statement and use commercially reasonable efforts to have such Resale Registration Statement become effective in accordance with the procedures described above.

2.2 Notification and Distribution of Materials . The Company shall notify the Holders in writing of the effectiveness of the Resale Shelf Registration Statement and shall furnish to the Holders, without charge, such number of copies of the Resale Shelf Registration Statement (including any amendments, supplements and exhibits), the Prospectus contained therein (including each preliminary prospectus and all related amendments and supplements) and any documents incorporated by reference in the Resale Shelf Registration Statement or such other documents as the Holders may reasonably request in order to facilitate the sale of the Registrable Securities in the manner described in the Resale Shelf Registration Statement.

2.3 Amendments and Supplements . Subject to the provisions of Section 2.1 above, the Company shall promptly prepare and file with the SEC from time to time such amendments and supplements to the Resale Shelf Registration Statement and Prospectus used in connection therewith as may be necessary to keep the Resale Shelf Registration Statement effective and to comply with the provisions of the Securities Act with respect to the disposition of all the Registrable Securities during the Effectiveness Period.

2.4 Notice of Certain Events . The Company shall promptly notify the Holders in writing of any request by the SEC for any amendment or supplement to, or additional information in connection with, the Resale Shelf Registration Statement required to be prepared and filed hereunder (or Prospectus relating thereto). The Company shall promptly notify each Holder in writing of the filing of the Resale Shelf Registration Statement or any Prospectus, amendment or supplement related thereto or any post-effective amendment to the Resale Shelf Registration Statement and the effectiveness of any post-effective amendment.

3. Underwritten Offering Rights .

3.1 Subject to the conditions set forth in this Agreement, the Company shall, at the written request of any Holder or Holders (the “ Initiating Holders ”) to sell in an underwritten offering at any time during the Effectiveness Period that number of Registrable Securities with an aggregate Fair Market Value of not less than $5,000,000 as of the date of such request (or any lesser aggregate amount if such request is with respect to all to the Registrable Securities of such Initiating Holder(s) under this Agreement) (an “ Underwritten Demand Notice ”), cause to be prepared and filed as soon as reasonably practicable after the date of such

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Underwritten Demand Notice (and in any event within 45 days of such Underwritten Demand Notice, provided that, in the event that there are any Non-Initiating Holders, such filing shall not occur prior to the date that is 10 days after the date on which the Company provides notice to the Non-Initiating Holders of the receipt of the Underwritten Demand Notice) either:

(a) in the event that the Resale Shelf Registration Statement has not been declared effective, is not currently effective, or ceases to be usable and the Company is not eligible to file a registration statement on Form S-3 (or any similar or successor form) for the purpose of registering the resale of the Registrable Securities, a registration statement; or

(b) a (1) supplement to the Prospectus contained in the Resale Shelf Registration Statement, (2) post-effective amendment to the Resale Shelf Registration Statement, or (3) Form 8-K incorporated by reference into the Resale Shelf Registration Statement in accordance with the rules under the Securities Act (or such other rule as is applicable to the proposed sale);

(each document referred to in clauses (a) and (b) is referred to as an “ Underwritten Demand Statement ”), in each case covering all the Registrable Securities requested to be included in such underwritten offering by the Initiating Holders, plus the Registrable Securities requested to be included in such underwritten offering by the Holders, if any, other than the Initiating Holders (the “ Non-Initiating Holders ”) in a notice received by the Company within 10 days of the date on which the Company provides notice to the Non-Initiating Holders of the receipt of the Underwritten Demand Notice, less any such Registrable Securities subsequently withdrawn from such underwritten offering by a Holder or as a result of reductions in accordance with Section 3.7 below (such total number of Registrable Securities being referred to herein as the “ Underwritten Demand Shares ”); provided , however , that the Company shall not be required to effect an Underwritten Demand Statement pursuant to a request under this Section 3.1 more than 5 times for the Holders of Registrable Securities collectively; and provided , further , that no Holder shall be entitled to demand an Underwritten Demand Statement during a Suspension Event or Offering Blackout Period. An Underwritten Demand Statement shall be deemed to have been effected, for the purposes of the number of requests that may be made by the Holders, upon the earlier of (x) the date as of which all of the Underwritten Demand Shares shall have been disposed of pursuant to the Underwritten Demand Statement and (y) the 90 ^th day following the later of (A) the filing of a preliminary prospectus with the SEC covering all of the Underwritten Demand Shares for sale in accordance with the method of disposition specified by the Initiating Holders or (B) the effectiveness of the registration statement registering the sale of all of the Underwritten Demand Shares for sale in accordance with the method of disposition specified by the Initiating Holders unless, with respect to this clause (y), during such 90-day period there was a Suspension Event or the Company delivered a notice pursuant to Section 4.2 prior to the sale of 75% of the Underwritten Demand Shares covered or registered thereby and the Holders of a majority of the Underwritten Demand Shares, within 2 Business Days after the occurrence of a Suspension Event or the delivery of a notice from the Company pursuant to Section 4.2 , determine to terminate the offering and provide written notice thereof to the Company. Additionally, an Underwritten Demand Statement shall be deemed to be have been effected, in the event that, upon the request of the Initiating Holders, the Company files a registration statement to register the sale of all of the Underwritten Demand Shares for sale in accordance with the method of disposition specified by the Initiating Holders, but such registration statement does not become effective thereafter solely by reason of the refusal of the Holders to proceed with an underwritten offering thereunder unless such refusal occurs, and notice of such refusal is provided to the Company, within 2 Business Days after the occurrence of a Suspension Event or the delivery of a notice from the Company pursuant to Section 4.2 . Within 5 days following its receipt of an Underwritten Demand Notice, the Company will provide notice to the Non-Initiating Holders of the receipt of the Underwritten Demand Notice. For purposes of clarity, the Parties acknowledge and agree that an Underwritten Demand Notice may be issued by the Initiating Holders prior to the Effectiveness Period.

3.2 The Company shall use its commercially reasonable efforts to have the Underwritten Demand Statement declared effective under the Securities Act, if required, as expeditiously as reasonably practicable following the filing of such Underwritten Demand Statement. Any Underwritten Demand Statement filed under this Section 3 shall reflect such plan or method of distribution of the applicable securities as shall be designated by the managing underwriter.

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3.3 The Company shall have the right to postpone the filing or the effectiveness of each Underwritten Demand Statement pursuant to this Section 3 as provided in Section 4 .

3.4 Notwithstanding anything to the contrary contained herein, no request may be made under this Section 3 within six (6) months after the completion of an underwritten offering pursuant to any Underwritten Demand Notice.

3.5 The Holders of a majority of the Underwritten Demand Shares shall be entitled to select nationally recognized investment banks to act as the underwriters for such offering; provided that such selection shall be subject to the consent of the Company (which consent shall not be unreasonably withheld, delayed or conditioned).

3.6 The Company shall make available members of the management of the Company for reasonable assistance in selling efforts related to such offering (including, without limitation, senior management attendance at due diligence meetings with underwriters and their counsel and road shows) and shall enter into underwriting agreements containing usual and customary terms and conditions for such types of offerings and take all such other actions in connection therewith customarily undertaken by issuers in order to expedite or facilitate the disposition of such Registrable Securities, including without limitation: (i) making such representations and warranties to the underwriters with respect to the business of the Company, the registration statement pursuant to which the sale of the Underwritten Demand Shares is to be registered, the Prospectus and any documents, if any, incorporated or deemed to be incorporated by reference therein, as may reasonably be required by the underwriters; (ii) obtaining opinions of counsel to the Company and updates thereof, addressed to Holders and each of the underwriters; (iii) obtaining “cold comfort” letters and updates thereof from the independent certified public accountants of the Company addressed to Holders and each of the underwriters; (iv) ensuring that, if an underwriting agreement is entered into, such agreement shall contain indemnification provisions and procedures that are usual and customary for an offering of such size; (v) filing with the SEC a final Prospectus with respect to the offering that satisfies the requirements of Section 10(a) of the Securities Act as soon as practicable following the pricing of the offering and, in any event, prior to the first scheduled date for delivery by the Holders to the underwriters or purchasers of Registrable Securities in the offering; and (vi) delivering such documents and certificates as may be reasonably requested by the underwriters and their respective counsel to evidence the continued validity of the representations and warranties made pursuant to clause (i) of this Section 3.6.

3.7 In connection with an Underwritten Demand Statement, if the managing underwriter of such offering reasonably determines in writing that the number of securities sought to be offered should be limited due to market conditions, then the number of securities to be included in such underwritten public offering shall be reduced to a number deemed satisfactory by such managing underwriter; provided, however, that securities shall be excluded in the following sequence: (i) first, shares of Common Stock held by any stockholders not having rights to include such shares in the underwritten public offering; (ii) second, shares of Common Stock held by stockholders having contractual, incidental “piggy back” rights to include such shares in the underwritten public offering other than Registrable Securities or shares of Common Stock held by stockholders having contractual, incidental “piggy back” rights to include such shares in the underwritten public offering pursuant to that certain Registration Rights Agreement, dated as of November 3, 1999, by and among the Company and certain of its stockholders (the “ Prior Registrable Securities ”); (iii) third, shares of Common Stock sought to be registered by the Company for its own account; and (iv) fourth, Registrable Securities and Prior Registrable Securities. If there is a reduction of some but not all of the number of shares pursuant to clauses (i) through (iv), such reduction shall be made on a pro rata basis (based upon the aggregate number of securities held by the holders in the applicable category and subject to the priorities set forth in the preceding sentence).

3.8 The Company shall promptly notify the Holders in writing of the effectiveness, if required, of any Underwritten Demand Statement and shall furnish to the Holders, without charge, such number of copies of the Registration Statement (including any amendments, supplements and exhibits), the Prospectus contained therein (including each preliminary prospectus and all related amendments and supplements) and any

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documents incorporated by reference in the Registration Statement or such other documents as the Holders may reasonably request in order to facilitate the sale of the Registrable Securities in the manner described in the Underwritten Demand Statement.

3.9 The Company shall promptly notify in writing each Holder of Registrable Securities covered by such registration statement of any comments made to the Company or its counsel by the SEC with respect thereto or any request made to the Company or its counsel by the SEC for amendments or supplements to such registration statement or prospectus or for additional information (and furnish counsel for the selling Holder(s) copies of such comment letters and requests).

4. Suspension of Registration Requirement; Market Standstill.

4.1 The Company shall promptly notify each Holder in writing of the issuance by the SEC of any stop order suspending the effectiveness of a Registration Statement with respect to such Holder’s Registrable Securities or the initiation of any proceedings for that purpose. The Company shall use commercially reasonable efforts to obtain the withdrawal of any order suspending the effectiveness of such a Registration Statement as promptly as reasonably possible and promptly notify in writing each Holder of Registrable Securities covered by such registration statement of the withdrawal of any such order.

4.2 At any time when a Prospectus relating to a Registration Statement is required to be delivered under the Securities Act to a transferee, the Company shall immediately notify each Selling Holder (A) of the happening of any event as a result of which the Prospectus included in such Registration Statement, as then in effect, includes an untrue statement of a material fact or omits to state any material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading, and (B) in such event, to suspend sales of Registrable Securities, and each Selling Holder will refrain from selling any Registrable Securities pursuant to such Registration Statement until the Selling Holders are advised in writing by the Company that the current Prospectus may be used, and has received copies of any additional or supplemental filings that are incorporated or deemed incorporated by reference in any such Prospectus. In such event, unless such event constitutes a Suspension Event (as defined below), the Company shall promptly, and in any event within 15 Business Days, prepare and file a supplement to or an amendment of such Prospectus as may be necessary so that, as supplemented or amended, such Prospectus shall not include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they are made, not misleading. The Company shall, if necessary, promptly, and in any event within 15 Business Days, amend the Registration Statement of which such Prospectus is a part to reflect such amendment or supplement. The Company shall promptly notify the Selling Holders in writing when the current Prospectus may be used.

4.3 Subject to the terms of Section 5 below, the Company’s obligation under this Agreement to file, amend or supplement a Registration Statement, or to cause a Registration Statement, or any filings with any state securities commission, to become effective shall be deferred, for one or more reasonable periods, each of which may not to exceed 90 days, if the Board of Directors of the Company determines in good faith that such deferral is in the best interest of the Company and its stockholders in order to avoid the disclosure of information not otherwise then required by law (in the absence of a registration or sales thereunder) to be publicly disclosed (such circumstances being hereinafter referred to as a “ Suspension Event ”). The Company shall notify the Holders of the existence of any Suspension Event by promptly delivering to each Holder a certificate signed by an executive officer of the Company (“ Suspension Event Certificate ”) stating that a Suspension Event has occurred and is continuing and setting forth the duration of such Suspension Event, (not to exceed 90 days from delivery of the Suspension Event Certificate), or if such duration is not known, the anticipated duration of such Suspension Event (not to exceed 90 days from the delivery of the Suspension Event Certificate). If the Suspension Event Certificate does not set forth a definitive duration of the Suspension event, then upon the earlier of (i) 90 days following delivery of the Suspension Event Certificate or (ii) the conclusion of the Suspension Event, the Company shall notify the Holders in writing of the termination of the Suspension Event.

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4.4 Subject to the terms of Section 5 below, each Holder of Registrable Securities agrees, if requested by the managing underwriter or underwriters in a Company-initiated underwritten offering (each, a “ Company Offering ”), not to effect any public sale or distribution of any of the Registrable Securities or request an Underwritten Demand Statement during an Offering Blackout Period, provided that the Company is actively employing in good faith commercially reasonable efforts to cause the registration statement associated with such Offering Blackout Period to be effective, if it has not already become effective. The Company shall use commercially reasonable efforts to give written notice to each Holder of any Offering Blackout Period at least 15 days prior to the commencement of the Offering Blackout Period; provided , however , that if the Company is unable to provide 15 days advance notice of the commencement of the Offering Blackout Period, the Company shall provide as much notice as reasonably possible, and provided further that the failure to timely provide such notice shall not in any way prohibit the commencement of an Offering Blackout Period. The “ Offering Blackout Period ” shall commence on a date set by the Company, which shall be no earlier than the 15 ^th day preceding the anticipated date of pricing of such Company Offering, and shall end on the 150th day, or such sooner date as is requested by the managing underwriter or underwriters in such Company Offering, after the closing date of such Company Offering.

5. Limitations on Suspension/Blackout Periods. Notwithstanding anything herein to the contrary, the Company covenants and agrees that (a) the Company’s rights to defer certain of its obligations pursuant to Section 4.3 during the pendency of any Suspension Event, and (b) the Holders’ obligation to suspend public sales of Registrable Securities pursuant to Section 4.4 during one or more Offering Blackout Periods, shall not, in the aggregate, cause the Holders to be required to suspend sales of Registrable Securities or relieve the Company of its obligation to file a Registration Statement for longer than 180 days during any 12-month period.

6. Piggyback Registration Rights. If the Company proposes to register in an underwritten offering any of its shares of Common Stock under the Securities Act for sale to the public (other than a registration effected solely to implement an employee benefit plan or a transaction to which Rule 145 of the Securities Act is applicable, or a registration statement on Form S-4, S-8 or another form not available for registering the Registrable Securities for sale to the public, or in connection with an Underwritten Demand Statement), each such time it will give written notice to each Holder. Upon the written request of any of such Holders, given within 10 Business Days after receipt by such Person of such notice, the Company shall, subject to the limits contained in this Section 6 , use its commercially reasonable efforts to cause all Registrable Securities requested by such Holders to be registered under the Securities Act and qualified for sale under any state securities or “blue sky” law, to the extent required to permit the sale of their Registrable Securities in such underwritten public offering; provided , however , that if the managing underwriter or underwriters of such offering reasonably determine in writing that the number of securities sought to be offered should be limited due to market conditions, then the number of securities to be included in such underwritten public offering shall be reduced to a number deemed satisfactory by such managing underwriter or underwriters; provided , however , that securities shall be excluded in the following sequence: (i) first, shares of Common Stock held by any stockholders not having rights to include such shares in the underwritten public offering; (ii) second, shares of Common Stock held by stockholders having contractual, incidental “piggy back” rights to include such shares in the underwritten public offering other than Registrable Securities and Prior Registrable Securities; (iii) third, Registrable Securities and Prior Registrable Securities; and (iv) fourth, shares of Common Stock sought to be registered by the Company for its own account. If there is a reduction of some but not all of the number of shares pursuant to clauses (i) through (iv), such reduction shall be made on a pro rata basis (based upon the aggregate number of securities held by the holders in the applicable category and subject to the priorities set forth in the preceding sentence). Additionally, the Company shall not be required to register any Registrable Securities pursuant to this Section 6 unless the Holders of such Registrable Securities accept the terms of the underwriting agreed upon between the Company and the underwriters selected by the Company (or by other persons entitled to select the underwriters). All Holders proposing to distribute their securities through such underwriting shall (together with the Company and any other stockholders proposing to distribute their securities through such underwriting) enter into an underwriting agreement in customary form with the underwriters.

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7. Termination of Registration Rights . The rights granted pursuant to Sections 2 , 3 and 6 shall terminate, as to any Holder, at such time at which all Registrable Securities held by such Holder can be sold in any three- month period without registration in compliance with Rule 144; provided , however , that it shall be assumed that no Holder will be eligible to sell any Registrable Securities pursuant to Rule 144(k) during the Class B Period.

8. State Securities Laws and Sale Procedures.

8.1 The Company shall use its commercially reasonable efforts to file documents required of the Company for normal blue sky clearance in states specified in writing by the Holders; provided, however, that the Company shall not be required to qualify to do business or consent to service of process in any jurisdiction in which it is not now so qualified or has not so consented.

8.2 Each Holder agrees that it will not effect any disposition of the Registrable Securities that would constitute a sale within the meaning of the Securities Act other than transactions exempt from the registration requirements of the Securities Act or as contemplated in a Registration Statement.

8.3 In the event of a sale of Registrable Securities by the Holder, unless such requirement is waived by the Company in writing, the Holder must also deliver to the Company’s transfer agent, with a copy to the Company, a Certificate of Subsequent Sale substantially in the form attached hereto as Exhibit A , so that the Registrable Securities may be properly transferred.

9. Indemnification by the Company . The Company agrees to indemnify and hold harmless the Holders and, if a Holder is a person other than an individual, such Holder’s officers, directors, employees, agents, representatives and Affiliates, and each Person, if any, that controls a Holder within the meaning of the Securities Act, and each other Person, if any, subject to liability because of his, her or its connection with a Holder (each, an “ Indemnitee ”), against any and all losses, claims, damages, actions, liabilities, costs, and expenses (including without limitation reasonable fees, expenses and disbursements of attorneys and other professionals), joint or several, arising out of or based upon (i) any violation (or alleged violation) by the Company of the Securities Act, the Exchange Act or state securities laws and relating to action or inaction required of the Company under the terms of this Agreement or in connection with any Registration Statement or Prospectus; (ii) any untrue (or alleged untrue) statement of material fact contained in any Registration Statement or any Prospectus; or (iii) any omission (or alleged omission) to state therein a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading; provided , however , that the Company shall not be liable to such Indemnitee or any person who participates as an underwriter in the offering or sale of Registrable Securities or any other person, if any, who controls such underwriter within the meaning of the Securities Act, in any such case to the extent that any such loss, claim, damage, liability (or action or proceeding in respect thereof) or expense arises out of or is based upon (a) an untrue statement (or alleged untrue statement) or omission (or alleged omission) made in such Registration Statement or in any such Prospectus in reliance upon and in conformity with information regarding such Indemnitee or its plan of distribution or ownership interests which was furnished in writing to the Company for use in connection with such Registration Statement or the Prospectus contained therein by such Indemnitee, (b) any Holder’s failure to send or give a copy of the final, amended or supplemented prospectus furnished to the Holders by the Company at or prior to the time such action is required by the Securities Act to the person claiming an untrue statement or alleged untrue statement or omission or alleged omission if such statement or omission was corrected in such final, amended or supplemented Prospectus, or (c) an untrue statement or alleged untrue statement contained in any offer made by a Holder relating to the Registrable Securities that constitutes a “free writing prospectus” as defined in Rule 405 of the Securities Act.

10. Covenants of the Holder . Each of the Holders hereby agrees (i) to cooperate with the Company and to furnish to the Company the information concerning such Holder, its plan of distribution and its ownership interests in securities of the Company in connection with the preparation of a Registration Statement or Prospectus with respect to such Holder’s Registrable Securities and any filings with any state securities commissions as the Company may reasonably request (and to promptly notify the Company of any material changes in such information set forth in a Registration Statement prior to and during the effectiveness of such

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Registration Statement), (ii) if the Company complies with its obligations to timely file a final Prospectus pursuant to Section 3.6 of this Agreement relating to a sale of Registrable Securities of such Holder, to deliver or cause delivery of such final Prospectus to any purchaser of such Registrable Securities from such Holder if the Holder is required by the Securities Act or the rules and regulations thereunder to deliver the Prospectus in connection with the sale of such Registrable Securities to such purchaser; provided , however , that no delivery of the Prospectus shall be required of any Holder pursuant to this subsection (ii) if such Prospectus is deemed delivered pursuant to Rule 172 under the Securities Act, (iii) that it will not make any offer relating to the Registrable Securities that would constitute a “free writing prospectus” as defined in Rule 405 under the Securities Act, and (iv) to indemnify the Company, its officers, directors, employees, agents, representatives and Affiliates, and each person, if any, who controls the Company within the meaning of the Securities Act, and each other person or entity, if any, subject to liability because of his, her or its connection with the Company, against any and all losses, claims, damages, actions, liabilities, costs and expenses arising out of or based upon (A) any untrue statement or alleged untrue statement of material fact contained in either such Registration Statement or the Prospectus contained therein, or any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading, if and to the extent that such statement or omission occurs from reliance upon and in conformity with written information regarding such Holder, his, her or its plan of distribution or his, her or its ownership interests, which was furnished to the Company in writing by such Holder for use therein, (B) if the Company complies with its obligations to timely file a final Prospectus pursuant to Section 3.6 of this Agreement relating to a sale of Registrable Securities of such Holder, the failure by such Holder to deliver or cause delivery of such final Prospectus to any purchaser of such Registrable Securities from such Holder if the Holder is required by the Securities Act or the rules and regulations thereunder to deliver the Prospectus in connection with the sale of such Registrable Securities to such purchaser; provided that, for purposes of this subsection (B), such failure shall not include in any event any deemed delivery of such Prospectus pursuant to Rule 172 under the Securities Act or (C) an untrue statement or alleged untrue statement contained in any offer made by such Holder relating to the Registrable Securities that constitutes a “free writing prospectus” as defined in Rule 405 of the Securities Act.

11. Indemnification Procedures . Any Person entitled to indemnification under this Agreement shall notify promptly the indemnifying party in writing of the commencement of any action or proceeding of which such Person has actual knowledge and with respect to which a claim for indemnification may be made hereunder, but the failure of any indemnified party to provide such notice shall not relieve the indemnifying party of its obligations hereunder, except to the extent the indemnifying party is materially prejudiced thereby and shall not relieve the indemnifying party from any liability which it may have to any indemnified party otherwise than hereunder. In case any action or proceeding is brought against an indemnified party and it shall notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate therein and, unless in the reasonable opinion of outside counsel to the indemnified party a conflict of interest between such indemnified and indemnifying parties may exist in respect of such claim, to assume the defense thereof (alone or jointly with any other indemnifying party similarly notified), to the extent that it chooses, with counsel reasonably satisfactory to such indemnified party, and after notice from the indemnifying party to such indemnified party that it so chooses ( provided that in connection with such assumption the indemnifying parties provide the indemnified parties a full release of any costs or other expenses in connection therewith), the indemnifying party shall not be liable to such indemnified party for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof; provided , however , that (a) if the indemnifying party fails to take reasonable steps necessary to defend diligently the action or proceeding within 15 Business Days after receiving notice from such indemnified party that the indemnified party believes it has failed to do so; or (b) if such indemnified party who is a defendant in any action or proceeding which is also brought against the indemnifying party shall have reasonably concluded, based on the advice of counsel, that there may be one or more legal defenses available to such indemnified party which are not available to the indemnifying party; or (c) if representation of both parties by the same counsel is otherwise inappropriate under applicable standards of professional conduct, then, in any such case, the indemnified party shall have the right to assume or continue its own defense as set forth above (but with no more than one firm of counsel for all

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indemnified parties in each jurisdiction) and the indemnifying party shall be liable for any expenses therefor, in which case the indemnifying party shall pay or reimburse such legal or other expenses as they are incurred. No indemnifying party shall, without the written consent of the indemnified party (which shall not be unreasonably withheld), effect the settlement or compromise of, or consent to the entry of any judgment with respect to, any pending or (to the knowledge of the indemnifying party) threatened action or claim in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified party is an actual or potential party to such action or claim) unless such settlement, compromise or judgment (i) includes an unconditional release of the indemnified party from all liability arising out of such action or claim, (ii) does not include a statement as to or an admission of fault, culpability or a failure to act, by or on behalf of any indemnified party and (iii) does not and is not likely to materially adversely affect the indemnified party.

12. Contribution .

12.1 If the indemnification provided for in Section 9 and Section 10 is unavailable to an indemnified party with respect to any losses, claims, damages, actions, liabilities, costs or expenses referred to therein or is insufficient to hold the indemnified party harmless as contemplated therein, then the indemnifying party, in lieu of indemnifying such indemnified party, shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages, actions, liabilities, costs or expenses in such proportion as is appropriate to reflect the relative fault of the indemnifying party, on the one hand, and the indemnified party, on the other hand, in connection with the statements or omissions which resulted in such losses, claims, damages, actions, liabilities, costs or expenses as well as any other relevant equitable considerations. The relative fault of the indemnifying party, on the one hand, and of the indemnified party, on the other hand, shall be determined by reference to, among other factors, whether the untrue or alleged untrue statement of a material fact or omission to state a material fact relates to information supplied by the indemnifying party or by the indemnified party and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission; provided , however , that in no event shall the obligation of any indemnifying party to contribute under this Section 12 exceed the amount that such indemnifying party would have been obligated to pay by way of indemnification if the indemnification provided for under Section 9 or Section 10 hereof had been available under the circumstances.

12.2 The Company and the Holders agree that it would not be just and equitable if contribution pursuant to this Section 12 were determined by pro rata allocation or by any other method of allocation that does not take account of the equitable considerations referred to in the immediately preceding paragraph.

12.3 Notwithstanding the provisions of this Section 12 , no Holder shall be required to contribute any amount in excess of the amount by which the gross proceeds from the sale of Registrable Securities exceeds the amount of any damages that such Holder has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission. No indemnified party guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any indemnifying party who was not guilty of such fraudulent misrepresentation.

13. Expenses . The Company shall bear all Registration Expenses incurred in connection with the registration of the Registrable Securities in connection with the registration of the Registrable Securities pursuant to Section 2 hereof and the registration of Registrable Securities pursuant to the first three (3) Underwritten Demand Statements effected pursuant to Section 3.1 . The Holders shall bear all Registration Expenses incurred in connection with the registration of the Registrable Securities pursuant to all Underwritten Demand Statements effected pursuant to Section 3.1 other than the first three (3). The Holders shall also bear all underwriting fees, discounts or commissions attributable to the sale of securities by the Holders, or any legal fees and expenses of counsel to the Holders and any underwriter engaged in connection with an Underwritten Demand Statement and all other expenses incurred in connection with the performance by the Holders of their obligations under the terms of this Agreement.

14. Transfer of Registration Rights . Subject to the restrictions in the Investor Rights Agreement on the right to transfer the Shares or the Registrable Securities, the rights of a Holder under this Agreement may be

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transferred by a Holder to a transferee who acquires Registrable Securities equal to at least 25% of the total number of Registrable Securities initially issuable upon conversion of all of the Shares initially issued to Initial Holder pursuant to the Stock Purchase Agreement (including all other securities issued or issuable in respect of such Registrable Securities by way of spin-off, dividend or stock split or in connection with a combination of shares, reclassification, merger, consolidation or reorganization), provided , however , that such transferee has executed and delivered to the Company a properly completed agreement to be bound by the terms of this Agreement substantially in the form attached hereto as Exhibit B (an “ Addendum Agreement ”), and the transferor shall have delivered to the Company, no later than 30 days following the date of the transfer, written notification of such transfer setting forth the name of the transferor, the name and address of the transferee, and the number of Registrable Securities so transferred. The execution of an Addendum Agreement shall constitute a permitted amendment of this Agreement.

15. Additional Shares . Except as otherwise provided in this Agreement, the Company, at its option, may register, under any Registration Statement and any filings with any state securities commissions filed pursuant to this Agreement, any number of unissued, treasury or other shares of Common Stock of or owned by the Company and any of its subsidiaries or any shares of Common Stock or other securities of the Company owned by any other security holder or security holders of the Company.

16. No Other Obligation to Register . Except as otherwise expressly provided in this Agreement, the Company shall have no obligation to the Holders to register the Registrable Securities under the Securities Act.

17. Rule 144 Reporting . With a view to making available the benefits of certain rules and regulations of the SEC that may permit the sale of the Registrable Securities to the public without registration, the Company agrees to use commercially reasonable efforts to:

(a) make and keep adequate current public information available pursuant to paragraph (c) of Rule 144;

(b) file with the SEC in a timely manner all reports and other documents required of the Company under the Exchange Act; and

(c) furnish to any Holder, so long as the Holder owns any Registrable Securities, forthwith upon request, a statement, if true, to the effect that it has complied with the reporting requirements of paragraph (c) Rule 144 and meets the eligibility requirements for use of Form S-3 set forth in Instruction I.A. and Form S-3.

18. Notices . All notices, requests, consents and other communications hereunder shall be in writing, in English, shall be delivered (A) if within the United States, by first-class registered or certified airmail, or nationally recognized overnight express courier, postage prepaid, or by facsimile, or (B) if from outside the United States, by a recognized international express courier service or facsimile, and shall be deemed given (i) if delivered by first-class registered or certified mail domestic, upon the business day received, (ii) if delivered by nationally recognized overnight carrier, one (1) business day after timely delivery to such carrier, (iii) if delivered by a recognized international express courier service, two (2) Business Days after timely delivery to such carrier, (iv) if delivered by facsimile, upon electric confirmation of receipt and shall be addressed as follows, or to such other address or addresses as may have been furnished in writing by a party to another party pursuant to this Section 18 :

if to the Company, to:

Plug Power Inc.

968 Albany Shaker Road,

Latham, New York 12110

Attention: General Counsel

Facsimile: (518) 782-7884

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with a copy (which shall not constitute notice) to:

Goodwin Procter LLP

Exchange Place

Boston, Massachusetts 02109

Attention: Robert P. Whalen, Jr.

Facsimile: (617) 532-1231

if to the Holder, to:

Smart Hydrogen Inc.

c/o Interros Holding Company

9, Bolshaya Yakimanka Street

119180 Moscow

Russian Federation

Attn: Marianna Zakharova

Facsimile: 7-495-785-6362

with a copy (which shall not constitute notice) to:

Baker Botts L.L.P.

The Warner

1299 Pennsylvania Avenue, N.W.

Washington, DC 20004-2400

Attention: Gregory J. Golden

Facsimile: (202) 585-1025

In the event of transfer of Registrable Securities, notices given pursuant to this Agreement to a subsequent Holder shall be delivered to the relevant address specified in the relevant agreement in the form of Exhibit B whereby such Holder became bound by the provisions of this Agreement.

19. Amendments; Waiver . Except as permitted by Section 14 , this Agreement may not be modified or amended except pursuant to an instrument in writing signed by the Company and the Holders owning Registrable Securities possessing a majority in number of the Registrable Securities then outstanding. Any waiver of a provision of this Agreement must be in writing and executed by the Party against whom enforcement of such waiver is sought.

20. Headings . The headings of the various sections of this Agreement have been inserted for convenience of reference only and shall not be deemed to be part of this Agreement.

21. Entire Agreement; Severability . This Agreement, the Stock Purchase Agreement and the Investor Rights Agreement set forth the entire agreement and understanding of the parties relating to the subject matter hereof and supersede all prior and contemporaneous agreements, negotiations and understandings between the parties, both oral and written relating to the subject matter hereof. If any provision contained in this Agreement is determined to be invalid, illegal or unenforceable in any respect, the validity, legality and enforceability of the remaining provisions contained herein shall not in any way be affected or impaired thereby.

22. Governing Law . This Agreement shall be governed by, and construed in accordance with, the internal laws of the State of New York, without giving effect to the principles of conflicts of law.

23. Dispute Resolution .

23.1 The Parties shall endeavor to resolve any dispute, claim, or controversy arising out of or relating to this Agreement (including, but not limited to, the negotiation, validity, performance breach or termination thereof) (each, a “ Dispute ”) by non-binding mediation under the CPR Mediation Procedure then currently

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in effect. The mediator will be selected upon mutual agreement of the parties engaged in the Dispute (the “ Disputing Parties ”). Any Dispute which remains unresolved 30 days after the appointment of a mediator (or if the Disputing Parties are unable to agree upon a mediator within 30 days after a Disputing Party notifies another Disputing Party of a Dispute in writing), shall be finally resolved by arbitration in accordance with the CPR Rules for Non-Administered Arbitration, Revised and Effective June 15, 2005 (the “ Rules ”). A tribunal of three arbitrators will preside over any Dispute(s) (the “ Tribunal ”). Each Disputing Party shall appoint one arbitrator to the Tribunal or, if there are more than two Disputing Parties and the Company is one of the Disputing Parties, then the Company shall appoint one arbitrator and the other Disputing Parties shall jointly appoint one arbitrator. Within 30 days of the appointment of the second arbitrator, the two arbitrators appointed by the Disputing Parties shall appoint a third arbitrator, who shall chair the Tribunal (the “ Chairperson ”). In the event the arbitrators appointed by the Disputing Parties are unable to agree on the Chairperson, the Chairperson will be selected as provided in Rule 6 of the Rules. Under no circumstances shall the Chairperson be either an American or Russian citizen. The place of arbitration shall be New York, New York and the language of the arbitration shall be English. Upon the request of any Disputing Party, there shall be simultaneous translation of all communications with the Tribunal into English or Russian, as the case may be. The arbitration shall be governed by the Federal Arbitration Act, 9 U.S.C. §§ 1-16, and judgment upon or other enforcement of the award rendered by the arbitrator may be entered by the U.S. District Court for the Southern District of New York.

23.2 Unless otherwise agreed by the Disputing Parties, the Tribunal’s decision and award shall be made and delivered within 30 days of the conclusion of the arbitration. The Parties acknowledge that the Tribunal shall have the authority, with respect to any Dispute, to provide any and all relief, whether legal, equitable, or otherwise, and award any damages or remedy that a federal court in New York could provide or award with respect to such Dispute. The Tribunal shall have no jurisdiction, power, or authority to decide or award punitive or exemplary damages. It is the expressed intention of the Parties to mutually waive the right to seek or recover such damages from the other.

23.3 The Parties covenant and agree that they will share equally the costs of an arbitration pursuant to this Section 23 , except as otherwise provided herein. The Tribunal may in its discretion assess costs and expenses (including the reasonable legal fees and expenses of the prevailing party) against any Disputing Party to a proceeding. Any Disputing Party unsuccessfully refusing to comply with an award of the Tribunal shall be liable for costs and expenses, including reasonable attorneys’ fees, incurred by any other Disputing Party in enforcing the award.

23.4 Each Party irrevocably waives any objection to proceeding before the Tribunal in New York, to the extent provided in this Section 23 , based upon lack of personal jurisdiction or to the laying of venue and further irrevocably and unconditionally waives and agrees not to make a claim that arbitration in accordance with these provisions has been brought in an inconvenient forum. Each of the Parties hereby consents to service of notice for any arbitration pursuant to this Section 23 as provided for in Rule 2 of the Rules.

23.5 Notwithstanding the foregoing, the parties hereby consent to the sole and exclusive jurisdiction of the U.S. District Court for the Southern District of New York for any action, suit or proceeding to compel arbitration pursuant to this Section 23 , seek a preliminary injunction or other provisional judicial relief in aid of arbitration with respect to any Dispute, or obtain judgment upon or other enforcement of any award or decision rendered by the Tribunal pursuant to this Section 23 , and the Parties agree that the foregoing provisions requiring non-binding mediation and arbitration of Disputes shall not apply to any such action, suit, or proceeding. The Parties further hereby irrevocably and unconditionally waive any objection to the laying of venue of any such action, suit or proceeding in the U.S. District Court for the Southern District of New York and hereby further irrevocably and unconditionally waive and agree not to plead or claim in such court that any such action, suit, or proceeding brought in such court has been brought in an inconvenient forum. Each of the Parties further agrees that service of any process, summons, notice, or document by U.S. registered mail (with respect to any address in the United States) or by a recognized international express courier service, including, without limitation, International Federal Express (with respect to any address outside of the United States) to such party’s then current address for notice pursuant to Section 18 shall be

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effective service of process for any action, suit, or proceeding brought against it in such court. Each of the Parties agrees that its or his submission to jurisdiction and its or his consent to service of process in the manner described above is made for the express benefit of the other Parties.

23.6 The procedures specified in this Section 23 shall be the sole and exclusive procedures for the resolution of Disputes.

24. Counterparts . This Agreement may be executed in two or more counterparts, each of which shall constitute an original, but all of which, when taken together, shall constitute but one instrument, and shall become effective when one or more counterparts have been signed by each Party hereto and delivered to the other Party.

25. Drafting Conventions; No Construction Against the Drafter .

25.1 The headings in this Agreement are provided for convenience and do not affect its meaning. The words “include”, “includes” and “including” are to be read as if they were followed by the phrase “without limitation”. Unless specified otherwise, any reference to an agreement means that agreement as amended or supplemented, subject to any restrictions on amendment contained in such agreement. Unless specified otherwise, any reference to a statute or regulation means that statute or regulation as amended or supplemented from time to time and any corresponding provisions of successor statutes or regulations. If any date specified in this Agreement as a date for taking action falls on a day that is not a Business Day, then that action may be taken on the next Business Day.

25.2 The Parties have participated jointly with their respective counsel in the negotiation and drafting of this Agreement. If an ambiguity or question of intent or interpretation arises, this Agreement is to be construed as if drafted jointly by the Parties and there is to be no presumption or burden of proof favoring or disfavoring any Party because of the authorship of any provision of this Agreement.

[ Signature Page Follows ]

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IN WITNESS WHEREOF, the undersigned have executed this Agreement as of the date first written above.

[REGISTRATION RIGHTS AGREEMENT SIGNATURE PAGE]

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E XHIBIT A

PLUG POWER INC.

CERTIFICATE OF SUBSEQUENT SALE

[Transfer Agent]

Dear Sir/Madam:

The undersigned hereby certifies, in connection with the sale of shares of Common Stock of the Company included in the table of Selling Shareholders in the Prospectus, that the undersigned has sold the Shares pursuant to the Prospectus and in a manner described under the caption “Plan of Distribution” in the Prospectus and that such sale complies with all applicable securities laws, including, without limitation, the Prospectus delivery requirements of the Securities Act of 1933, as amended.

Selling Shareholder (the beneficial owner):                                                                                                       

Record Holder (e.g., if held in name of nominee):                                                                                             

Restricted Stock Certificate No.(s):                                                                                                                    

Number of Shares Sold:                                                                                                                                       

Date of Sale:                                                                                                                                                         

In the event that you receive a stock certificate(s) representing more shares of Common Stock than have been sold by the undersigned, then you should return to the undersigned a newly issued certificate for such excess shares in the name of the Record Holder and BEARING A RESTRICTIVE LEGEND. Further, you should place a stop transfer on your records with regard to such certificate.

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E XHIBIT B

AGREEMENT TO BE BOUND

BY THE REGISTRATION RIGHTS AGREEMENT

The undersigned, being the transferee of                  shares of Registrable Securities (as defined in the Registration Rights Agreement between Plug Power Inc. (the “Company”) and Smart Hydrogen Inc., dated June 29, 2006 (the “Registration Rights Agreement”)), as a condition to the receipt of such Registrable Securities, acknowledges that matters pertaining to the registration of the resale of such Registrable Securities is governed by the Registration Rights Agreement and the undersigned hereby: (1) acknowledges receipt of a copy of the Registration Rights Agreement, and (2) agrees to be bound as a Holder and a Party by the terms of the Registration Rights Agreement, as the same has been or may be amended from time to time.

Exhibit 99.3

FORM OF

INDEMNIFICATION AGREEMENT

This Agreement made and entered into this                      day of                      , (the “Agreement”), by and between Plug Power Inc., a Delaware corporation (the “Company,” which term shall include, where appropriate, any Entity (as hereinafter defined) controlled directly or indirectly by the Company) and                                  (the “Indemnitee”):

WHEREAS, it is essential to the Company that it be able to retain and attract as directors the most capable persons available;

WHEREAS, increased corporate litigation has subjected directors to litigation risks and expenses, and the limitations on the availability of directors and officers liability insurance have made it increasingly difficult for the Company to attract and retain such persons;

WHEREAS, the Company’s By-laws (the “By-laws”) require it to indemnify its directors to the fullest extent permitted by law and permit it to make other indemnification arrangements and agreements;

WHEREAS, the Company desires to provide Indemnitee with specific contractual assurance of Indemnitee’s rights to full indemnification against litigation risks and expenses (regardless, among other things, of any amendment to or revocation of the By-laws or any change in the ownership of the Company or the composition of its Board of Directors);

WHEREAS, the Company intends that this Agreement provide Indemnitee with greater protection than that which is provided by the By-laws; and

WHEREAS, Indemnitee is relying upon the rights afforded under this Agreement in [becoming] [continuing as] a director of the Company.

NOW, THEREFORE, in consideration of the promises and the covenants contained herein, the Company and Indemnitee do hereby covenant and agree as follows:

1. Definitions .

(a) “Corporate Status” describes the status of a person who is serving or has served (i) as a director of the Company, (ii) in any capacity with respect to any employee benefit plan of the Company, or (iii) as a director, partner, trustee, officer, employee, or agent of any other Entity at the request of the Company. For purposes of subsection (iii) of this Section 1(a), if Indemnitee is serving or has served as a director, partner, trustee, officer, employee or agent of a Subsidiary, Indemnitee shall be deemed to be serving at the request of the Company.

(b) “Entity” shall mean any corporation, partnership, limited liability company, joint venture, trust, foundation, association, organization or other legal entity.

(c) “Expenses” shall mean all fees, costs and expenses incurred by Indemnitee in connection with any Proceeding (as defined below), including, without limitation, attorneys’ fees, disbursements and retainers (including, without limitation, any such fees, disbursements and retainers incurred by Indemnitee pursuant to Sections 10 and 11(c) of this Agreement), fees and disbursements of expert witnesses, private investigators and professional advisors (including, without limitation, accountants and investment bankers), court costs, transcript costs, fees of experts, travel expenses, duplicating, printing and binding costs, telephone and fax transmission charges, postage, delivery services, secretarial services, and other disbursements and expenses.

(d) “Indemnifiable Expenses,” “Indemnifiable Liabilities” and “Indemnifiable Amounts” shall have the meanings ascribed to those terms in Section 3(a) below.

(e) “Liabilities” shall mean judgments, damages, liabilities, losses, penalties, excise taxes, fines and amounts paid in settlement.

(f) “Proceeding” shall mean any threatened, pending or completed claim, action, suit, arbitration, alternate dispute resolution process, investigation, administrative hearing, appeal, or any other proceeding, whether civil, criminal, administrative, arbitrative or investigative, whether formal or informal, including a proceeding initiated by Indemnitee pursuant to Section 10 of this Agreement to enforce Indemnitee’s rights hereunder.

(g) “Subsidiary” shall mean any corporation, partnership, limited liability company, joint venture, trust or other Entity of which the Company owns (either directly or through or together with another Subsidiary of the Company) either (i) a general partner, managing member or other similar interest or (ii) (A) 50% or more of the voting power of the voting capital equity interests of such corporation, partnership, limited liability company, joint venture or other Entity, or (B) 50% or more of the outstanding voting capital stock or other voting equity interests of such corporation, partnership, limited liability company, joint venture or other Entity.

2. Services of Indemnitee . In consideration of the Company’s covenants and commitments hereunder, Indemnitee agrees to serve or continue to serve as a director of the Company. However, this Agreement shall not impose any obligation on Indemnitee or the Company to continue Indemnitee’s service to the Company beyond any period otherwise required by law or by other agreements or commitments of the parties, if any.

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3. Agreement to Indemnify . The Company agrees to indemnify Indemnitee as follows:

(a) Proceedings Other Than By or In the Right of the Company . Subject to the exceptions contained in Section 4(a) below, if Indemnitee was or is a party or is threatened to be made a party to any Proceeding (other than an action by or in the right of the Company) by reason of Indemnitee’s Corporate Status, Indemnitee shall be indemnified by the Company against all Expenses and Liabilities incurred or paid by Indemnitee in connection with such Proceeding (referred to herein as “Indemnifiable Expenses” and “Indemnifiable Liabilities,” respectively, and collectively as “Indemnifiable Amounts”).

(b) Proceedings By or In the Right of the Company . Subject to the exceptions contained in Section 4(b) below, if Indemnitee was or is a party or is threatened to be made a party to any Proceeding by or in the right of the Company by reason of Indemnitee’s Corporate Status, Indemnitee shall be indemnified by the Company against all Indemnifiable Expenses.

(c) Expenses as a Witness . To the extent that Indemnitee is, by reason of his or her Corporate Status, a witness in any Proceeding to which Indemnitee is not a party and is not threatened to be made a party, Indemnitee shall be indemnified by the Company against all Expenses incurred or paid by Indemnitee in connection therewith, which Expenses shall be considered Indemnifiable Expenses for purposes of this Agreement.

(d) Conclusive Presumption Regarding Standard of Care . In making any determination required to be made under Delaware law with respect to entitlement to indemnification hereunder, the person, persons or entity making such determination shall presume that Indemnitee is entitled to indemnification under this Agreement if Indemnitee submitted a request therefor in accordance with Section 5 of this Agreement, and the Company shall have the burden of proof to overcome that presumption in connection with the making by any person, persons or entity of any determination contrary to that presumption.

4. Exceptions to Indemnification . Indemnitee shall be entitled to indemnification under Sections 3(a) and 3(b) above in all circumstances other than with respect to any specific claim, issue or matter involved in the Proceeding out of which Indemnitee’s claim for indemnification has arisen, as follows:

(a) Proceedings Other Than By or In the Right of the Company . If indemnification is requested under Section 3(a) and it has been finally adjudicated by a court of competent jurisdiction that, in connection with such specific claim, issue or matter, Indemnitee failed to act (i) in good faith and (ii) in a manner Indemnitee reasonably believed to be in or not opposed to the best interests of the Company, or, with respect to any criminal Proceeding, Indemnitee had reasonable cause to believe that Indemnitee’s conduct was unlawful, Indemnitee shall not be entitled to payment of Indemnifiable Amounts hereunder.

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(b) Proceedings By or In the Right of the Company . If indemnification is requested under Section 3(b) and

(i) it has been finally adjudicated by a court of competent jurisdiction that, in connection with such specific claim, issue or matter, Indemnitee failed to act (A) in good faith and (B) in a manner Indemnitee reasonably believed to be in or not opposed to the best interests of the Company, Indemnitee shall not be entitled to payment of Indemnifiable Expenses hereunder; or

(ii) it has been finally adjudicated by a court of competent jurisdiction that Indemnitee is liable to the Company with respect to such specific claim, Indemnitee shall not be entitled to payment of Indemnifiable Expenses hereunder with respect to such claim, issue or matter unless the Court of Chancery or another court in which such Proceeding was brought shall determine upon application that, despite the adjudication of liability, but in view of all the circumstances of the case, Indemnitee is fairly and reasonably entitled to indemnification for such Indemnifiable Expenses which such court shall deem proper; or

(iii) it has been finally adjudicated by a court of competent jurisdiction that Indemnitee is liable to the Company for an accounting of profits made from the purchase or sale by the Indemnitee of securities of the Company pursuant to the provisions of Section 16(b) of the Securities Exchange Act of 1934, the rules and regulations promulgated thereunder and amendments thereto or similar provisions of any federal, state or local statutory law, Indemnitee shall not be entitled to payment of Indemnifiable Expenses hereunder.

(c) Insurance Proceeds . To the extent payment is actually made to the Indemnitee under a valid and collectible insurance policy in respect of Indemnifiable Amounts in connection with such specific claim, issue or matter, Indemnitee shall not be entitled to payment of Indemnifiable Amounts hereunder except in respect of any excess beyond the amount of payment under such insurance.

5. Procedure for Payment of Indemnifiable Amounts . Indemnitee shall submit to the Company a written request specifying the Indemnifiable Amounts for which Indemnitee seeks payment under Section 3 of this Agreement and the basis for the claim. The Company shall pay such Indemnifiable Amounts to Indemnitee promptly upon receipt of its request. At the request of the Company, Indemnitee shall furnish such documentation and information as are reasonably available to Indemnitee and necessary to establish that Indemnitee is entitled to indemnification hereunder.

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6. Indemnification for Expenses of a Party Who is Wholly or Partly Successful . Notwithstanding any other provision of this Agreement, and without limiting any such provision, to the extent that Indemnitee is, by reason of Indemnitee’s Corporate Status, a party to and is successful, on the merits or otherwise, in any Proceeding, Indemnitee shall be indemnified against all Expenses reasonably incurred by Indemnitee or on Indemnitee’s behalf in connection therewith. If Indemnitee is not wholly successful in such Proceeding but is successful, on the merits or otherwise, as to one or more but less than all claims, issues or matters in such Proceeding, the Company shall indemnify Indemnitee against all Expenses reasonably incurred by Indemnitee or on Indemnitee’s behalf in connection with each successfully resolved claim, issue or matter. For purposes of this Agreement, the termination of any claim, issue or matter in such a Proceeding by withdrawal or dismissal, with or without prejudice, shall be deemed to be a successful result as to such claim, issue or matter.

7. Effect of Certain Resolutions . Neither the settlement or termination of any Proceeding nor the failure of the Company to award indemnification or to determine that indemnification is payable shall create a presumption that Indemnitee is not entitled to indemnification hereunder. In addition, the termination of any proceeding by judgment, order, settlement, conviction, or upon a plea of nolo contendere or its equivalent shall not create a presumption that Indemnitee did not act in good faith and in a manner which Indemnitee reasonably believed to be in or not opposed to the best interests of the Company or, with respect to any criminal Proceeding, had reasonable cause to believe that Indemnitee’s action was unlawful.

8. Agreement to Advance Expenses; Undertaking . The Company shall advance all Expenses incurred by or on behalf of Indemnitee in connection with any Proceeding, including a Proceeding by or in the right of the Company, in which Indemnitee is involved by reason of such Indemnitee’s Corporate Status within ten (10) calendar days after the receipt by the Company of a written statement from Indemnitee requesting such advance or advances from time to time, whether prior to or after final disposition of such Proceeding, unless it has been finally determined by a court of competent jurisdiction that Indemnitee is not entitled under this Agreement to indemnification with respect to such Expenses. To the extent required by Delaware law, Indemnitee hereby undertakes to repay any and all of the amount of Indemnifiable Expenses paid to Indemnitee if it is finally determined by a court of competent jurisdiction that Indemnitee is not entitled under this Agreement to indemnification with respect to such Expenses. This undertaking is an unlimited general obligation of Indemnitee.

9. Procedure for Advance Payment of Expenses . Indemnitee shall submit to the Company a written request specifying the Indemnifiable Expenses for which Indemnitee seeks an advancement under Section 8 of this Agreement, together with documentation evidencing that Indemnitee has incurred such Indemnifiable Expenses. Payment of Indemnifiable Expenses under Section 8 shall be made no later than ten (10) calendar days after the Company’s receipt of such request.

10. Remedies of Indemnitee .

(a) Right to Petition Court . In the event that Indemnitee makes a request for payment of Indemnifiable Amounts under Sections 3 and 5 above or a request for

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an advancement of Indemnifiable Expenses under Sections 8 and 9 above and the Company fails to make such payment or advancement in a timely manner pursuant to the terms of this Agreement, Indemnitee may petition the Court of Chancery to enforce the Company’s obligations under this Agreement.

(b) Burden of Proof . In any judicial proceeding brought under Section 10(a) above, the Company shall have the burden of proving that Indemnitee is not entitled to payment of Indemnifiable Amounts hereunder.

(c) Expenses . The Company agrees to reimburse Indemnitee in full for any Expenses incurred by Indemnitee in connection with investigating, preparing for, litigating, defending or settling any action brought by Indemnitee under Section 10(a) above, or in connection with any claim or counterclaim brought by the Company in connection therewith, whether or not Indemnitee is successful in whole or in part in connection with any such action.

(d) Failure to Act Not a Defense . The failure of the Company (including its Board of Directors or any committee thereof, independent legal counsel, or stockholders) to make a determination concerning the permissibility of the payment of Indemnifiable Amounts or the advancement of Indemnifiable Expenses under this Agreement shall not be a defense in any action brought under Section 10(a) above, and shall not create a presumption that such payment or advancement is not permissible.

11. Defense of the Underlying Proceeding .

(a) Notice by Indemnitee . Indemnitee agrees to notify the Company promptly upon being served with any summons, citation, subpoena, complaint, indictment, information, or other document relating to any Proceeding which may result in the payment of Indemnifiable Amounts or the advancement of Indemnifiable Expenses hereunder; provided, however, that the failure to give any such notice shall not disqualify Indemnitee from the right, or otherwise affect in any manner any right of Indemnitee, to receive payments of Indemnifiable Amounts or advancements of Indemnifiable Expenses unless the Company’s ability to defend in such Proceeding is materially and adversely prejudiced thereby.

(b) Defense by Company . Subject to the provisions of the last sentence of this Section 11(b) and of Section 11(c) below, the Company shall have the right to defend Indemnitee in any Proceeding which may give rise to the payment of Indemnifiable Amounts hereunder; provided, however that the Company shall notify Indemnitee of any such decision to defend within ten (10) calendar days of receipt of notice of any such Proceeding under Section 11(a) above. The Company shall not, without the prior written consent of Indemnitee, consent to the entry of any judgment against Indemnitee or enter into any settlement or compromise which (i) includes an admission of fault of Indemnitee or (ii) does not include, as an unconditional term thereof, the full release of Indemnitee from all liability in respect of such Proceeding, which release shall be in form and

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substance reasonably satisfactory to Indemnitee. This Section 11(b) shall not apply to a Proceeding brought by Indemnitee under Section 10(a) above or pursuant to Section 19 below.

(c) Indemnitee’s Right to Counsel . Notwithstanding the provisions of Section 11(b) above, if in a Proceeding to which Indemnitee is a party by reason of Indemnitee’s Corporate Status, (i) Indemnitee reasonably concludes that he or she may have separate defenses or counterclaims to assert with respect to any issue which may not be consistent with the position of other defendants in such Proceeding, (ii) a conflict of interest or potential conflict of interest exists between Indemnitee and the Company, or (iii) if the Company fails to assume the defense of such proceeding in a timely manner, Indemnitee shall be entitled to be represented by separate legal counsel of Indemnitee’s choice at the expense of the Company. In addition, if the Company fails to comply with any of its obligations under this Agreement or in the event that the Company or any other person takes any action to declare this Agreement void or unenforceable, or institutes any action, suit or proceeding to deny or to recover from Indemnitee the benefits intended to be provided to Indemnitee hereunder, Indemnitee shall have the right to retain counsel of Indemnitee’s choice, at the expense of the Company, to represent Indemnitee in connection with any such matter.

12. Representations and Warranties of the Company . The Company hereby represents and warrants to Indemnitee as follows:

(a) Authority . The Company has all necessary power and authority to enter into, and be bound by the terms of, this Agreement, and the execution, delivery and performance of the undertakings contemplated by this Agreement have been duly authorized by the Company.

(b) Enforceability . This Agreement, when executed and delivered by the Company in accordance with the provisions hereof, shall be a legal, valid and binding obligation of the Company, enforceable against the Company in accordance with its terms, except as such enforceability may be limited by applicable bankruptcy, insolvency, moratorium, reorganization or similar laws affecting the enforcement of creditors’ rights generally.

13. Insurance . The Company shall, from time to time, make the good faith determination whether or not it is practicable for the Company to obtain and maintain a policy or policies of insurance with a reputable insurance company providing the Indemnitee with coverage for losses from wrongful acts. For so long as Indemnitee shall remain a director of the Company and with respect to any such prior service, in all policies of director and officer liability insurance, Indemnitee shall be named as an insured in such a manner as to provide Indemnitee the same rights and benefits as are accorded to the most favorably insured of the Company’s officers and directors. Notwithstanding the foregoing, the Company shall have no obligation to obtain or maintain such insurance if the Company determines in good faith that such insurance is not reasonably available, if the premium costs for such insurance are disproportionate to the amount of coverage provided, or if the coverage provided by such insurance is limited by exclusions so as to provide an insufficient benefit. The Company shall promptly notify Indemnitee of any good faith determination not to provide such coverage.

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14. Contract Rights Not Exclusive . The rights to payment of Indemnifiable Amounts and advancement of Indemnifiable Expenses provided by this Agreement shall be in addition to, but not exclusive of, any other rights which Indemnitee may have at any time under applicable law, the Company’s Certificate of Incorporation or By-laws, or any other agreement, vote of stockholders or directors (or a committee of directors), or otherwise, both as to action in Indemnitee’s official capacity and as to action in any other capacity as a result of Indemnitee’s serving as a director of the Company.

15. Successors . This Agreement shall be (a) binding upon all successors and assigns of the Company (including any transferee of all or a substantial portion of the business, stock and/or assets of the Company and any direct or indirect successor by merger or consolidation or otherwise by operation of law) and (b) binding on and shall inure to the benefit of the heirs, personal representatives, executors and administrators of Indemnitee. This Agreement shall continue for the benefit of Indemnitee and such heirs, personal representatives, executors and administrators after Indemnitee has ceased to have Corporate Status.

16. Subrogation . In the event of any payment of Indemnifiable Amounts under this Agreement, the Company shall be subrogated to the extent of such payment to all of the rights of contribution or recovery of Indemnitee against other persons, and Indemnitee shall take, at the request of the Company, all reasonable action necessary to secure such rights, including the execution of such documents as are necessary to enable the Company to bring suit to enforce such rights.

17. Change in Law . To the extent that a change in Delaware law (whether by statute or judicial decision) shall permit broader indemnification or advancement of expenses than is provided under the terms of the By-laws and this Agreement, Indemnitee shall be entitled to such broader indemnification and advancements, and this Agreement shall be deemed to be amended to such extent.

18. Severability . Whenever possible, each provision of this Agreement shall be interpreted in such a manner as to be effective and valid under applicable law, but if any provision of this Agreement, or any clause thereof, shall be determined by a court of competent jurisdiction to be illegal, invalid or unenforceable, in whole or in part, such provision or clause shall be limited or modified in its application to the minimum extent necessary to make such provision or clause valid, legal and enforceable, and the remaining provisions and clauses of this Agreement shall remain fully enforceable and binding on the parties.

19. Indemnitee as Plaintiff . Except as provided in Section 10(c) of this Agreement and in the next sentence, Indemnitee shall not be entitled to payment of Indemnifiable Amounts or advancement of Indemnifiable Expenses with respect to any Proceeding brought by Indemnitee against the Company, any Entity which it controls, any director or officer thereof, or any third party, unless the Board of Directors of the Company has consented to the initiation of such Proceeding. This Section shall not apply to counterclaims or affirmative defenses asserted by Indemnitee in an action brought against Indemnitee.

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20. Modifications and Waiver . Except as provided in Section 17 above with respect to changes in Delaware law which broaden the right of Indemnitee to be indemnified by the Company, no supplement, modification or amendment of this Agreement shall be binding unless executed in writing by each of the parties hereto. No waiver of any of the provisions of this Agreement shall be deemed or shall constitute a waiver of any other provisions of this Agreement (whether or not similar), nor shall such waiver constitute a continuing waiver.

21. Contribution . To the fullest extent permissible under applicable law, if the indemnification provided for in this Agreement is unavailable to Indemnitee in whole or in part for any reason whatsoever (other than because Indemnitee is not entitled to such indemnification pursuant to the terms of this Agreement), the Company, in lieu of indemnifying Indemnitee, shall contribute to the amount incurred by Indemnitee, whether for judgments, fines, penalties, excise taxes, amounts paid or to be paid in settlement and/or for Expenses, in connection with any claim relating to an indemnifiable event under this Agreement, in such proportion as is deemed fair and reasonable in light of all of the circumstances of such Proceeding in order to reflect (i) the relative benefits received by the Company and Indemnitee as a result of the event(s) and/or transaction(s) giving cause to such Proceeding; and (ii) the relative fault of the Company (and its directors, officers, employees and agents) and Indemnitee in connection with such event(s) and/or transaction(s). Additionally, to the fullest extent permitted under applicable law, if the indemnification provided for in this Agreement is unavailable to Indemnitee in whole or in part for any reason whatsoever (other than because Indemnitee is not entitled to such indemnification pursuant to the terms of this Agreement) in a Proceeding in which the Company is jointly liable with Indemnitee (or would be if joined in such Proceeding), the Company shall pay, in the first instance, the entire amount of any judgment or settlement of such Proceeding (except for any such amount that is paid by a third party) without requiring Indemnitee to contribute to such payment, and the Company hereby waives and relinquishes any right of contribution it may have against Indemnitee with respect to such Proceeding.

22. General Notices . All notices, requests, demands and other communications hereunder shall be in writing and shall be deemed to have been duly given (a) when delivered by hand, (b) when transmitted by facsimile and receipt is acknowledged, or (c) if mailed by certified or registered mail with postage prepaid, on the third business day after the date on which it is so mailed:

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or to such other address as may have been furnished in the same manner by any party to the others.

23. Governing Law; Consent to Jurisdiction; Service of Process . This Agreement shall be governed by and construed in accordance with the laws of the State of Delaware without regard to its rules of conflict of laws. Each of the Company and the Indemnitee hereby irrevocably and unconditionally consents to submit to the exclusive jurisdiction of the Court of Chancery of the State of Delaware and the courts of the United States of America located in the State of Delaware (the “Delaware Courts”) for any litigation arising out of or relating to this Agreement and the transactions contemplated hereby (and agrees not to commence any litigation relating thereto except in such courts), waives any objection to the laying of venue of any such litigation in the Delaware Courts and agrees not to plead or claim in any Delaware Court that such litigation brought therein has been brought in an inconvenient forum. Each of the parties hereto agrees, (a) to the extent such party is not otherwise subject to service of process in the State of Delaware, to appoint and maintain an agent in the State of Delaware as such party’s agent for acceptance of legal process, and (b) that service of process may also be made on such party by prepaid certified mail with a proof of mailing receipt validated by the United States Postal Service constituting evidence of valid service. Service made pursuant to (a) or (b) above shall have the same legal force and effect as if served upon such party personally within the State of Delaware. For purposes of implementing the parties’ agreement to appoint and maintain an agent for service of process in the State of Delaware, each such party does hereby appoint The Corporation Trust Company, 1209 Orange Street, Wilmington, New Castle County, Delaware 19801, as such agent and each such party hereby agrees to complete all actions necessary for such appointment.

[signature page follows]

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IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the day and year first above written.

Exhibit 99.4

EXECUTIVE SEVERANCE AGREEMENT

AGREEMENT made as of this 29th day of June, 2006 by and between Plug Power Inc., a Delaware corporation with its principal place of business in Latham, New York (the “Company”), and Tom Hutchison (the “Executive”).

1. Purpose . The Company considers it essential to the best interests of its stockholders to promote and preserve the continuous employment of key management personnel. The Board of Directors of the Company (the “Board”) recognizes, however, that, as is the case with many publicly held corporations, the possibility of a Change in Control (as defined in Section 2 hereof) exists and that such possibility, and the uncertainty and questions which it may raise among management, may result in the departure or distraction of management personnel to the detriment of the Company and its stockholders. Therefore, the Board has determined that appropriate steps should be taken to reinforce and encourage the continued attention and dedication of members of the Company’s management, including the Executive, to their assigned duties without distraction in the face of potentially disturbing circumstances arising from the possibility of a Change in Control. Nothing in this Agreement shall be construed as creating an express or implied contract of employment and, except as otherwise agreed in writing between the Executive and the Company, the Executive shall not have any right to be retained in the employ of the Company.

2. Change in Control . A “Change in Control” shall be deemed to have occurred in any one of the following events:

(a) any “person,” as such term is used in Sections 13(d) and 14(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), (other than the Company, any of its subsidiaries, any trustee, fiduciary or other person or entity holding securities under any employee benefit plan or trust of the Company or any of its subsidiaries, or, subject to the consummation of the transactions described in that certain Stock Purchase Agreement, dated as of April 10, 2006, by and between the Company and Smart Hydrogen Inc., a BVI Business Company (“Smart Hydrogen”), as the same may be amended from time to time (the “Stock Purchase Agreement”), Smart Hydrogen and any Permitted Transferee (as defined in the Certificate of Designations of Class B Capital Stock attached as Exhibit A to the Stock Purchase Agreement, as the same is filed with the Delaware Secretary of State and may be amended from time to time (the “Class B Certificate of Designations”)), together with all Affiliates and Associates (as such terms are hereinafter defined) of such person, shall become the “beneficial owner” (as such term is defined in Rule 13d-3 of the Exchange Act), directly or indirectly, of securities of the Company representing 25% or more of the then outstanding shares of common stock of the Company (the “Stock”) (other than as a result of an acquisition of securities directly from the Company); or

(b) persons who, as of the effective date of this Agreement (the “Effective Date”), constitute the Company’s Board of Directors (the “Incumbent Directors”) cease for any reason, including, without limitation, as a result of a tender

offer, proxy contest, merger or similar transaction, to constitute at least a majority of the Board, provided that any person becoming a director of the Company subsequent to the Effective Date shall be considered an Incumbent Director if such person’s election was approved by or such person was nominated for election by either (i) a vote of at least a majority of the Incumbent Directors or (ii) a vote of at least a majority of the Incumbent Directors who are members of a nominating committee comprised, in the majority, of Incumbent Directors; but provided further, that any such person whose initial assumption of office is in connection with an actual or threatened election contest relating to the election of members of the Board of Directors or other actual or threatened solicitation of proxies or consents by or on behalf of a Person other than the Board, including by reason of agreement intended to avoid or settle any such actual or threatened contest or solicitation, shall not be considered an Incumbent Director; or

(c) Upon (A) the consummation of any consolidation or merger of the Company where the shareholders of the Company, immediately prior to the consolidation or merger, did not, immediately after the consolidation or merger, beneficially own (as such term is defined in Rule 13d-3 of the Exchange Act), directly or indirectly, shares representing in the aggregate more than 50% of the voting shares of the corporation issuing cash or securities in the consolidation or merger (or of its ultimate parent corporation, if any), (B) the consummation of any sale, lease, exchange or other transfer (in one transaction or a series of transactions contemplated or arranged by any party as a single plan) of all or substantially all of the assets of the Company or (C) the completion of a liquidation or dissolution that has been approved by the stockholders of the Company; or

(d) Smart Hydrogen or any Permitted Transferee (as defined in the Class B Certificate of Designations), together with all Affiliates and Associates (as such terms are hereinafter defined) of such person, shall become the “beneficial owner” (as such term is defined in Rule 13d-3 of the Exchange Act), directly or indirectly, of securities of the Company representing 50% or more of the then outstanding Stock (other than as a result of an acquisition of securities directly from the Company).

Notwithstanding the foregoing, a “Change in Control” shall not be deemed to have occurred for purposes of the foregoing clauses (a) or (d) solely as the result of an acquisition of securities by the Company which, by reducing the number of shares of Stock outstanding, increases the proportionate number of shares of Stock beneficially owned by any person to 25% or more (or 50% or more in the case of clause (d)) of the shares of Stock then outstanding; provided, however, that if any such person shall at any time following such acquisition of securities by the Company become the beneficial owner of any additional shares of Stock (other than pursuant to a stock split, stock dividend, or similar transaction) and such person immediately thereafter is the beneficial owner of 25% or more (or 50% or more in the case of clause (d)) of the shares of Stock then outstanding, then a “Change in Control” shall be deemed to have occurred for purposes of the foregoing clause (a) or (d), as applicable.

(e) For purposes of this Agreement, “Affiliate” and “Associate” shall have the respective meanings ascribed to such terms in Rule 12b-2 of the Exchange Act,

as in effect on the date of this Agreement; provided , however , that no person who is a director or officer of the Company shall be deemed an Affiliate or an Associate of any other director or officer of the Company solely as a result of his position as director or officer of the Company.

3. Terminating Event . A “Terminating Event” shall mean any of the events provided in this Section 3 occurring subsequent to a Change in Control as defined in Section 2:

(a) termination by the Company of the employment of the Executive with the Company for any reason other than (A) a willful act of dishonesty by the Executive with respect to any matter involving the Company or any subsidiary or affiliate, or (B) conviction of the Executive of a crime involving moral turpitude, or (C) the gross or willful failure by the Executive to substantially perform the Executive’s duties with the Company (other than any such failure after the Executive gives notice of termination for “Good Reason”), which failure is not cured within 30 days after a written demand for substantial performance is received by the Executive from the Board of Directors of the Company which specifically identifies the manner in which the Board of Directors believes the Executive has not substantially performed the Executive’s duties, or (D) the failure by the Executive to perform his full-time duties with the Company by reason of his death or disability; provided, however, that a Terminating Event shall not be deemed to have occurred pursuant to this Section 3(a) solely as a result of the Executive being an employee of any direct or indirect successor to the business or assets of the Company, rather than continuing as an employee of the Company following a Change in Control. For purposes of clauses (A) and (C) of this Section 3(a), no act, or failure to act, on the Executive’s part shall be deemed “willful” unless done, or omitted to be done, by the Executive without reasonable belief that the Executive’s act, or failure to act, was in the best interests of the Company and its subsidiaries and affiliates. For purposes of clause (D) of this Section 3(a), Section 6 and Section 8(b) hereof, “disability” shall mean the Executive’s incapacity due to physical or mental illness which has caused the Executive to be absent from the full-time performance of his duties with the Company for a period of six (6) consecutive months if the Company shall have given the Executive a Notice of Termination and, within thirty (30) days after such Notice of Termination is given, the Executive shall not have returned to the full-time performance of his duties.

(b) termination by the Executive of the Executive’s employment with the Company for “Good Reason.” “Good Reason” shall mean the occurrence of any of the following events:

(i) a material adverse change, not consented to by the Executive, in the nature or scope of the Executive’s responsibilities, authorities, powers, functions or duties from the responsibilities, authorities, powers, functions or duties exercised by the Executive immediately prior to the Change in Control; or

(ii) a reduction in the Executive’s annual base salary as in effect on the date hereof or as the same may be increased from time to time hereafter; or

(iii) unless otherwise consented to by the Executive, the relocation of the Company’s offices at which the Executive is principally employed

immediately prior to the date of a Change in Control (the “Current Offices”) to any other location more than fifty (50) miles from the Current Offices, or the requirement by the Company for the Executive to be based anywhere other than the Current Offices, except for required travel on the Company’s business to an extent substantially consistent with the Executive’s business travel obligations immediately prior to the Change in Control; or

(iv) the failure by the Company to pay to the Executive any portion of his compensation or to pay to the Executive any portion of an installment of deferred compensation under any deferred compensation program of the Company within fifteen (15) days of the date such compensation is due without prior written consent of the Executive; or

(v) the failure by the Company to obtain an effective agreement from any successor to assume and agree to perform this Agreement, as required by Section 18.

4. Severance Payment . In the event a Terminating Event occurs within twelve (12) months after a Change in Control,

(a) the Company shall pay to the Executive an amount equal to the sum of (i) the Executive’s average annual base salary over the three (3) fiscal years immediately prior to the Terminating Event (or the Executive’s annual base salary in effect immediately prior to the Change in Control, if higher) and (ii) the Executive’s average annual bonus over the three (3) fiscal years immediately prior to the Change in Control (or the Executive’s annual bonus for the last fiscal year immediately prior to the Change in Control, if higher), payable in one lump-sum payment no later than five (5) days following the Date of Termination; and

(b) the Executive shall continue to vest in Executive’s options, in accordance with the governing stock options and all of the terms of those plans shall continue to be in effect, as though Executive had remained an active employee, for twelve (12) months; and

(c) the Company shall, regardless of whether the Company is unable to utilize Company-related benefit plans, continue to provide to the Executive certain benefits, including, without limitation, health, dental and life insurance on the same terms and conditions as though the Executive had remained an active employee, for twelve (12) months; and

(d) the Company shall provide COBRA benefits to the Executive following the end of the period referred to in Section 4(b) above, such benefits to be determined as though the Executive’s employment had terminated at the end of such period; and

(e) the Company shall pay to the Executive all reasonable legal and arbitration fees and expenses incurred by the Executive in obtaining or enforcing any right or benefit provided by this Agreement, except in cases involving frivolous or bad faith litigation.

5. Additional Limitation .

(a) Anything in this Agreement to the contrary notwithstanding, in the event that any compensation, payment or distribution by the Company to or for the benefit of the Executive, whether paid or payable or distributed or distributable pursuant to the terms of this Agreement or otherwise (the “Severance Payments”), would be subject to the excise tax imposed by Section 4999 of the Internal Revenue Code of 1986, as amended (the “Code”), the following provisions shall apply:

(i) If the Severance Payments, reduced by the sum of (A) the Excise Tax and (B) the total of the Federal, state, and local income and employment taxes payable by the Executive on the amount of the Severance Payments which are in excess of the Threshold Amount (as defined below), are greater than or equal to the Threshold Amount, the Executive shall be entitled to the full benefits payable under this Agreement.

(ii) If the Threshold Amount is less than (A) the Severance Payments, but greater than (B) the Severance Payments reduced by the sum of (1) the Excise Tax and (2) the total of the Federal, state, and local income and employment taxes on the amount of the Severance Payments which are in excess of the Threshold Amount, then the benefits payable under this Agreement shall be reduced (but not below zero) to the extent necessary so that the maximum Severance Payments shall not exceed the Threshold Amount. To the extent that there is more than one method of reducing the payments to bring them within the Threshold Amount, the Executive shall determine which method shall be followed; provided that if the Executive fails to make such determination within 45 days after the Company has sent the Executive written notice of the need for such reduction, the Company may determine the amount of such reduction in its sole discretion.

For the purposes of this Section 5, “Threshold Amount” shall mean three (3) times the Executive’s “base amount” within the meaning of Section 280G(b)(3) of the Code and the regulations promulgated thereunder less one dollar ($1.00); and “Excise Tax” shall mean the excise tax imposed by Section 4999 of the Code, and any interest or penalties incurred by the Executive with respect to such excise tax.

(b) The determination as to which of the alternative provisions of Section 5(a) shall apply to the Executive shall be made by a nationally recognized accounting firm selected by the Executive (the “Accounting Firm”), which shall provide detailed supporting calculations both to the Company and the Executive within fifteen (15) business days of the Date of Termination, if applicable, or at such earlier time as is reasonably requested by the Company or the Executive. For purposes of determining which of the alternative provisions of Section 5(a) shall apply, the Executive shall be deemed to pay federal income taxes at the highest marginal rate of federal income taxation applicable to individuals for the calendar year in which the determination is to be made, and state and local income taxes at the highest marginal rates of individual taxation in the state and locality of the Executive’s residence on the Date of Termination, net of the maximum reduction in federal income taxes which could be obtained from deduction of such state and local taxes. Any determination by the Accounting Firm shall be binding upon the Company and the Executive. The Company shall bear the costs of the Accounting Firm in connection with such firm’s services provided hereunder.

6. Term . This Agreement shall take effect on the date first set forth above and shall terminate upon the earlier of (a) the termination by the Company of the employment of the Executive because of (A) a willful act of dishonesty by the Executive with respect to any matter involving the Company or any subsidiary or affiliate, or (B) conviction of the Executive of a crime involving moral turpitude, or (C) the gross or willful failure by the Executive to substantially perform the Executive’s duties with the Company, or (D) the failure by the Executive to perform his full-time duties with the Company by reason of his death or disability (as defined in Section 3(a)), (b) the resignation or termination of the Executive for any reason prior to a Change in Control, (c) the termination of the Executive’s employment with the Company after a Change in Control for any reason other than the occurrence of any of the events enumerated in Section 3(b)(i)-(v) or Section 3(c) of this Agreement, or (d) the date which is twelve (12) months after a Change in Control if the Executive is still employed by the Company.

7. Withholding . All payments made by the Company under this Agreement shall be net of any tax or other amounts required to be withheld by the Company under applicable law.

8. Notice and Date of Termination; Disputes; Etc .

(a) Notice of Termination . After a Change in Control and during the term of this Agreement, any purported termination of the Executive’s employment (other than by reason of death) shall be communicated by written Notice of Termination from one party hereto to the other party hereto in accordance with this Section 8. For purposes of this Agreement, a “Notice of Termination” shall mean a notice which shall indicate the specific termination provision in this Agreement relied upon and the Date of Termination. Further, a Notice of Termination pursuant to one or more of clauses (A) through (C) of Section 3(a) hereof is required to include a copy of a resolution duly adopted by the affirmative vote of not less than two-thirds (2/3) of the entire membership of the Board at a meeting of the Board (after reasonable notice to the Executive and an opportunity for the Executive, accompanied by the Executive’s counsel, to be heard before the Board) finding that, in the good faith opinion of the Board, the termination met the criteria set forth in one or more of clauses (A) through (C) of Section 3(a) hereof.

(b) Date of Termination . “Date of Termination”, with respect to any purported termination of the Executive’s employment after a Change in Control and during the term of this Agreement, shall mean (i) if the Executive’s employment is terminated for disability, thirty (30) days after Notice of Termination is given (provided that the Executive shall not have returned to the full-time performance of the Executive’s duties during such 30-day period) and (ii) if the Executive’s employment is terminated for any other reason, the date specified in the Notice of Termination. In the case of a termination by the Company other than a termination pursuant to one or more of clauses (A) through (C) of Section 3(a) (which may be effective immediately), the Date of Termination shall not be less than 30 days after the Notice of Termination is given. In the case of a termination by the Executive, the Date of Termination shall not be less than fifteen (15) days from the date such Notice of Termination is given. Notwithstanding Section 3(a) of this Agreement, in the event that the Executive gives a Notice of

Termination to the Company, the Company may unilaterally accelerate the Date of Termination and such acceleration shall not result in a Terminating Event for purposes of Section 3(a) of this Agreement.

(c) No Mitigation . The Company agrees that, if the Executive’s employment by the Company is terminated during the term of this Agreement, the Executive is not required to seek other employment or to attempt in any way to reduce any amounts payable to the Executive by the Company pursuant to Sections 4(a) and (b) hereof. Further, the amount of any payment provided for in this Agreement shall not be reduced by any compensation earned by the Executive as the result of employment by another employer, by retirement benefits, by offset against any amount claimed to be owed by the Executive to the Company or otherwise.

(d) Settlement and Arbitration of Disputes . Any controversy or claim arising out of or relating to this Agreement or the breach thereof shall be settled exclusively by arbitration in accordance with the laws of the state of New York by three arbitrators, one of whom shall be appointed by the Company, one by the Executive and the third by the first two arbitrators. If the first two arbitrators cannot agree on the appointment of a third arbitrator, then the third arbitrator shall be appointed by the American Arbitration Association in the City of Albany. Such arbitration shall be conducted in the City of Boston in accordance with the rules of the American Arbitration Association for commercial arbitrations, except with respect to the selection of arbitrators which shall be as provided in this Section 8(d). Judgment upon the award rendered by the arbitrators may be entered in any court having jurisdiction thereof.

9. Successor to Executive . This Agreement shall inure to the benefit of and be enforceable by the Executive’s personal representatives, executors, administrators, heirs, distributees, devisees and legatees. In the event of the Executive’s death after a Terminating Event but prior to the completion by the Company of all payments due him under Section 4(a) and (b) of this Agreement, the Company shall continue such payments to the Executive’s beneficiary designated in writing to the Company prior to his death (or to his estate, if the Executive fails to make such designation).

10. Enforceability . If any portion or provision of this Agreement shall to any extent be declared illegal or unenforceable by a court of competent jurisdiction, then the remainder of this Agreement, or the application of such portion or provision in circumstances other than those as to which it is so declared illegal or unenforceable, shall not be affected thereby, and each portion and provision of this Agreement shall be valid and enforceable to the fullest extent permitted by law.

11. Waiver . No waiver of any provision hereof shall be effective unless made in writing and signed by the waiving party. The failure of any party to require the performance of any term or obligation of this Agreement, or the waiver by any party of any breach of this Agreement, shall not prevent any subsequent enforcement of such term or obligation or be deemed a waiver of any subsequent breach.

12. Notices . Any notices, requests, demands and other communications provided for by this Agreement shall be sufficient if in writing and delivered in person or sent by registered or certified mail, postage prepaid, to the Executive at the last address the Executive has filed in writing with the Company, or to the Company at its main office, attention of the Board of Directors.

13. Effect on Other Plans . An election by the Executive to resign after a Change in Control under the provisions of this Agreement shall not be deemed a voluntary termination of employment by the Executive for the purpose of interpreting the provisions of any of the Company’s benefit plans, programs or policies. Nothing in this Agreement shall be construed to limit the rights of the Executive under the Company’s benefit plans, programs or policies except as otherwise provided in Section 5 hereof, and except that the Executive shall have no rights to any severance benefits under any severance pay plan.

14. No Offset . The Company’s obligation to make the payments provided for in this Agreement and otherwise perform its obligations hereunder shall not be affected by any circumstances, including, without limitation, any set-off, counterclaim, recoupment, defense or other right which the Company or any of its Affiliates may have against the Executive or others whether by reason of the Executive’s breach of this Agreement, subsequent employment of the Executive, or otherwise.

15. Entire Agreement . This Agreement constitutes the entire agreement between the parties with respect to the subject matter hereof and supersedes in all respects all prior agreements between the parties concerning such subject matter.

16. Amendment . This Agreement may be amended or modified only by a written instrument signed by the Executive and by a duly authorized representative of the Company.

17. Governing Law . This is a New York contract and shall be construed under and be governed in all respects by the laws of the state of New York.

18. Obligations of Successors . The Company shall require any successor (whether direct or indirect, by purchase, merger, consolidation or otherwise) to all or substantially all of the business or assets of the Company to expressly assume and agree to perform this Agreement in the same manner and to the same extent that the Company would be required to perform if no such succession had taken place.

19. Confidential Information . The Executive shall never use, publish or disclose in a manner adverse to the Company’s interests, any proprietary or confidential information relating to (a) the business, operations or properties of the Company or any subsidiary or other affiliate of the Company, or (b) any materials, processes, business practices, technology, know-how, research, programs, customer lists, customer requirements or other information used in the manufacture, sale or marketing of any of the respective products or services of the Company or any subsidiary or other affiliate of the Company; provided , however , that no breach or alleged breach of this Section 19 shall entitle the Company to fail to comply fully and in a timely manner with any other provision hereof. Nothing in this Agreement shall preclude the Company from seeking money damages, or equitable relief by injunction or otherwise without the necessity of proving actual damage to the Company, for any breach by the Executive hereunder.

IN WITNESS WHEREOF, this Agreement has been executed as a sealed instrument by the Company by its duly authorized officer, and by the Executive, as of the date first above written.