Exhibit 10.3

EXECUTION VERSION

AMENDED AND RESTATED PERFORMANCE UNDERTAKING

THIS AMENDED AND RESTATED PERFORMANCE UNDERTAKING (this “Undertaking”), dated as of September 24, 2012, is executed by UNITED RENTALS, INC., a Delaware corporation (“Performance Guarantor”) in favor of UNITED RENTALS RECEIVABLES LLC II, a Delaware limited liability company (together with its successors and assigns, “Recipient”).

RECITALS

1. UNITED RENTALS (NORTH AMERICA), INC., a Delaware corporation (the “Originator”), Performance Guarantor and Recipient have entered into the Third Amended and Restated Purchase and Contribution Agreement, dated as of September 24, 2012 (as amended, restated or otherwise modified from time to time, the “Purchase Agreement”), pursuant to which the Originator, subject to the terms and conditions contained therein, is selling and/or contributing its right, title and interest in its accounts receivable to Recipient.

2. Performance Guarantor directly or indirectly owns one hundred percent (100%) of the capital stock of the Originator and Recipient, and accordingly, Performance Guarantor, is expected to receive substantial direct and indirect benefits from the sale or contribution of receivables by Originator to Recipient pursuant to the Purchase Agreement (which benefits are hereby acknowledged).

3. As an inducement for Recipient to acquire the Originator’s accounts receivable pursuant to the Purchase Agreement, Performance Guarantor has agreed to guaranty the due and punctual performance by the Originator of its obligations under the Purchase Agreement.

4. Performance Guarantor wishes to guaranty the due and punctual performance by the Originator of its obligations to Recipient under or in respect of the Purchase Agreement.

5. Performance Guarantor previously entered into that certain Performance Undertaking, dated as of May 31, 2005, in favor of Recipient and confirmed such undertaking as of December 22, 2008, September 28, 2011, and April 30, 2012 (the “Existing Performance Undertaking”). Performance Guarantor now desires to amend and restate the Existing Performance Undertaking in its entirety as set forth herein and with the effect from the date first set forth above.

AGREEMENT

NOW, THEREFORE, Performance Guarantor hereby agrees as follows:

Section 1. Definitions. Capitalized terms used herein and not defined herein shall have the respective meanings assigned thereto in the Purchase Agreement or the Receivables Purchase Agreement, dated as of September 24, 2012, by and among Recipient, as seller, Performance Guarantor, as collection agent, Liberty Street Funding LLC, as a purchaser (“Liberty”), Market Street Funding LLC, as a purchaser (“Market Street”), and Gotham Funding Corporation, as a purchaser (“Gotham” and, together with Liberty and Market Street, the “Purchasers”), The Bank of Nova Scotia, as a bank, as administrative agent and as purchaser agent for Liberty (“Scotia Bank” and the “Administrative Agent”), PNC Bank, National Association, as a bank and as the purchaser agent for Market Street (“PNC”), and The Bank of Tokyo-Mitsubishi UFJ, Ltd., New York Branch, as a bank and as the purchaser agent for Gotham (“BTMU” and, together with Scotia Bank and PNC, the “Purchaser Agents”) (as amended, restated or otherwise modified, the “Receivables Purchase Agreement” and together with the Purchase Agreement, the “Agreements”). In addition:

“Beneficiaries” means Recipient and its permitted assigns.

“Guaranteed Obligations” means, collectively, all covenants, agreements, terms, conditions and indemnities to be performed and observed by the Originator under and pursuant to the Purchase Agreement and each other document executed and delivered by the Originator pursuant to the Purchase Agreement, including, without limitation, the due and punctual payment of all sums that are or may become due and owing by the Originator under the Purchase Agreement, whether for fees, expenses (including counsel fees), indemnified amounts or otherwise, whether upon any termination or for any other reason.

Section 2. Guaranty of Performance of Guaranteed Obligations. Performance Guarantor hereby guarantees to Recipient, the full and punctual payment and performance by the Originator of its Guaranteed Obligations. This Undertaking is an absolute, unconditional and continuing guaranty of the full and punctual performance of all Guaranteed Obligations of the Originator under the Agreements and each other document executed and delivered by the Originator pursuant to the Agreements and is in no way conditioned upon any requirement that Recipient first attempt to collect any amounts owing by the Originator to Recipient, the Banks, the Purchasers, the Administrative Agent or the Purchaser Agents from any other Person or resort to any collateral security, any balance of any deposit account or credit on the books of Recipient, the Banks, the Purchasers, the Administrative Agent or the Purchaser Agents in favor of the Originator or any other Person or other means of obtaining payment. Should the Originator default in the payment or performance of any of its Guaranteed Obligations, Recipient (or its assigns) may cause the immediate performance by Performance Guarantor of the Guaranteed Obligations and cause any payment Guaranteed Obligations to become forthwith due and payable by Performance Guarantor to Recipient (or its assigns), without demand or notice of any nature (other than as expressly provided herein), all of which are hereby expressly waived by Performance Guarantor. Notwithstanding the foregoing, this Undertaking is not a guarantee of the collection of any of the Receivables and Performance Guarantor shall not be responsible for any Guaranteed Obligations to the extent the failure to perform such Guaranteed Obligations by the Originator results from Receivables being uncollectible on account of the insolvency, bankruptcy or lack of creditworthiness of the related Obligor; provided that nothing herein shall relieve the Originator from performing in full its Guaranteed Obligations under the Agreements or Performance Guarantor of its undertaking hereunder with respect to the full performance of such duties.

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Section 3. Performance Guarantor’s Further Agreements to Pay. Performance Guarantor further agrees, as the principal obligor and not as a guarantor only, to pay to Recipient (and its assigns), forthwith upon demand in funds immediately available to Recipient, all reasonable costs and expenses (including court costs and reasonable legal expenses) incurred or expended by Recipient in connection with the enforcement of this Undertaking, together with interest on amounts recoverable under this Undertaking from the time when such amounts become due until payment, at a rate of interest (computed for the actual number of days elapsed based on a 365 day year) equal to the Scotia Prime Rate plus 2% per annum, such rate of interest changing when and as the Scotia Prime Rate changes.

Section 4. Waivers by Performance Guarantor. Performance Guarantor waives notice of acceptance of this Undertaking, notice of any action taken or omitted by Recipient (or its assigns) in reliance on this Undertaking, and any requirement that Recipient (or its assigns) be diligent or prompt in making demands under this Undertaking, giving notice of any Event of Termination, other default or omission by the Originator or asserting any other rights of Recipient (or its assigns) under this Undertaking. Performance Guarantor warrants that it has adequate means to obtain from the Originator, on a continuing basis, information concerning the financial condition of the Originator, and that it is not relying on Recipient to provide such information, now or in the future. Performance Guarantor also irrevocably waives all defenses (1) that at any time may be available in respect of the Guaranteed Obligations by virtue of any statute of limitations, valuation, stay, moratorium law or other similar law now or hereafter in effect or (2) that arise under the law of suretyship, including impairment of collateral. Recipient (and its assigns) shall be at liberty, without giving notice to or obtaining the assent of Performance Guarantor and without relieving Performance Guarantor of any liability under this Undertaking, to deal with the Originator and with each other party who now is or after the date hereof becomes liable in any manner for any of the Guaranteed Obligations, in such manner as Recipient (or its assigns) in its sole discretion deems fit, and to this end Performance Guarantor agrees that the validity and enforceability of this Undertaking, including without limitation, the provisions of Section 8 hereof, shall not be impaired or affected by any of the following: (a) any extension, modification or renewal of, or indulgence with respect to, or substitutions for, the Guaranteed Obligations or any part thereof or any agreement relating thereto at any time; (b) any failure or omission to enforce any right, power or remedy with respect to the Guaranteed Obligations or any part thereof or any agreement relating thereto, or any collateral securing the Guaranteed Obligations or any part thereof; (c) any waiver of any right, power or remedy or of any Event of Termination or default with respect to the Guaranteed Obligations or any part thereof or any agreement relating thereto; (d) any release, surrender, compromise, settlement, waiver, subordination or modification, with or without consideration, of any other obligation of any person or entity with respect to the Guaranteed Obligations or any part thereof; (e) the enforceability or validity of the Guaranteed Obligations or any part thereof or the genuineness, enforceability or validity of any agreement relating thereto or with respect to the Guaranteed Obligations or any part thereof; (f) the application of payments received from any source to the payment of any payment obligations of the Originator or any part thereof or amounts which are not covered by this Undertaking even though Recipient (or its assigns) might lawfully have elected to apply such payments to any part or all of the payment obligations of the Originator or to amounts which are not covered by this Undertaking; (g) the existence of any claim, setoff or other rights which Performance Guarantor may have at any time against the Originator in connection herewith or any unrelated transaction; (h) any assignment or transfer of the Guaranteed Obligations or any part thereof; or (i) any failure on the part of the Originator to perform or comply with any term of the Purchase Agreement or any other document executed in connection therewith or delivered thereunder, all whether or not Performance Guarantor shall have had notice or knowledge of any act or omission referred to in the foregoing clauses (a) through (i) of this Section 4.

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Section 5. Unenforceability of Guaranteed Obligations Against Originators. Notwithstanding (i) any change of ownership of the Originator or the insolvency, bankruptcy or any other change in the legal status of the Originator; (ii) the change in or the imposition of any law, decree, regulation or other governmental act which does or might impair, delay or in any way affect the validity, enforceability or the payment when due of the Guaranteed Obligations; (iii) the failure of the Originator or Performance Guarantor to maintain in full force, validity or effect or to obtain or renew when required all governmental and other approvals, licenses or consents required in connection with the Guaranteed Obligations or this Undertaking, or to take any other action required in connection with the performance of all obligations pursuant to the Guaranteed Obligations or this Undertaking; or (iv) if any of the moneys included in the Guaranteed Obligations have become irrecoverable from the Originator for any other reason other than final payment in full of the payment obligations in accordance with their terms, this Undertaking shall nevertheless be binding on Performance Guarantor. This Undertaking shall be in addition to any other guaranty or other security for the Guaranteed Obligations, and it shall not be rendered unenforceable by the invalidity of any such other guaranty or security. In the event that acceleration of the time for payment of any of the Guaranteed Obligations is stayed upon the insolvency, bankruptcy or reorganization of the Originator or for any other reason with respect to the Originator, all such amounts then due and owing with respect to the Guaranteed Obligations under the terms of the Purchase Agreement, or any other agreement evidencing, securing or otherwise executed in connection with the Guaranteed Obligations, shall be immediately due and payable by Performance Guarantor.

Section 6. Representations and Warranties. Performance Guarantor hereby represents and warrants to Recipient that:

(a) Existence and Standing. Performance Guarantor is a corporation duly organized, validly existing and in good standing under the laws of its state of incorporation. Performance Guarantor is duly qualified to do business and is in good standing as a foreign corporation, and has and holds all corporate power and all governmental licenses, authorizations, consents and approvals required to carry on its business in each jurisdiction in which its business is conducted except where the failure to so qualify or so hold could not reasonably be expected to have a Material Adverse Effect.

(b) Authorization, Execution and Delivery; Binding Effect. The execution and delivery by Performance Guarantor of this Undertaking, and the performance of its obligations hereunder, are within its corporate powers and authority and have been duly authorized by all necessary corporate action on its part. This Undertaking has been duly executed and delivered by Performance Guarantor. This Undertaking constitutes the legal, valid and binding obligation of Performance Guarantor enforceable against Performance Guarantor in accordance with its terms, except as such enforcement may be limited by applicable bankruptcy, insolvency, reorganization or other similar laws relating to or limiting creditors’ rights generally and by general principles of equity (regardless of whether enforcement is sought in a proceeding in equity or at law).

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(c) No Conflict; Government Consent. The execution and delivery by Performance Guarantor of this Undertaking, and the performance of its obligations hereunder do not contravene or violate (1) its certificate or articles of incorporation or by-laws, (2) any law, rule or regulation applicable to it, (3) any restrictions under any agreement, contract or instrument to which it is a party or by which it or any of its property is bound, except, in any case, where such contravention or violation could not reasonably be expected to have a Material Adverse Effect.

(d) Taxes. Performance Guarantor has filed or caused to be filed all United States federal tax returns and all other tax returns which are required to be filed and have paid or caused to be paid all taxes due pursuant to said returns or pursuant to any assessment received by Performance Guarantor or any of its Subsidiaries, except (i) such taxes, if any, as are being contested in good faith and as to which adequate reserves have been provided; and (ii) to the extent that the failure to do so could not reasonably be expected to result in a Material Adverse Effect. To the Performance Guarantor’s knowledge, no federal or state tax liens have been filed and no material claims are being asserted with respect to any such taxes. In any event, any such claims and liens do not aggregate more than $1,000,000. The charges, accruals and reserves on the books of Performance Guarantor in respect of any taxes or other governmental charges are adequate.

(e) Litigation and Contingent Obligations. Except as disclosed in the filings made by Performance Guarantor with the Securities and Exchange Commission, there are no actions, suits or proceedings pending or, to the Performance Guarantor’s knowledge threatened against or affecting Performance Guarantor, in or before any court, arbitrator or other body, that could reasonably be expected (i) to have a Material Adverse Effect, or (ii) to adversely affect in any material respect the validity or enforceability of any of this Undertaking or the rights or remedies of Recipient hereunder. Performance Guarantor does not have any material contingent payment not provided for or disclosed to Recipient and its permitted assigns as of the date hereof.

Section 7. [Reserved]

Section 8. Subrogation; Subordination. Notwithstanding anything to the contrary contained herein, until the Guaranteed Obligations are paid in full Performance Guarantor: (i) will not enforce or otherwise exercise any right of subrogation to any of the rights of Recipient, the Administrative Agent, the Banks, the Purchaser Agents or the Purchasers against the Originator, (ii) hereby waives all rights of subrogation (whether contractual, under Section 509 of the United States Bankruptcy Code, at law or in equity or otherwise) to the claims of Recipient, the Administrative Agent, the Banks, the Purchaser Agents or the Purchasers against the Originator and all contractual, statutory or legal or equitable rights of contribution, reimbursement, indemnification and similar rights and “claims” (as that term is defined in the United States Bankruptcy Code) which Performance Guarantor might now have or hereafter acquire against the Originator that arise from the existence or performance of Performance

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Guarantor’s obligations hereunder, (iii) will not claim any setoff, recoupment or counterclaim against the Originator in respect of any liability of Performance Guarantor to the Originator and (iv) waives any benefit of and any right to participate in any collateral security which may be held by Beneficiaries, the Administrative Agent, the Banks, the Purchaser Agents or the Purchasers. The payment of any amounts due with respect to any indebtedness of the Originator now or hereafter owed to Performance Guarantor is hereby subordinated to the prior payment in full of all of the Guaranteed Obligations. Performance Guarantor agrees that, after the occurrence of any default in the payment or performance of any of the Guaranteed Obligations, Performance Guarantor will not demand, sue for or otherwise attempt to collect any such indebtedness of the Originator to Performance Guarantor until all of the Guaranteed Obligations shall have been paid and performed in full. If, notwithstanding the foregoing sentence, Performance Guarantor shall collect, enforce or receive any amounts in respect of such indebtedness while any Guaranteed Obligations are still unperformed or outstanding, such amounts shall be collected, enforced and received by Performance Guarantor as trustee for Recipient (and its assigns) and be paid over to Recipient (or its assigns) on account of and solely to the extent of such unperformed or outstanding Guaranteed Obligations without affecting in any manner the liability of Performance Guarantor under the other provisions of this Undertaking. The provisions of this Section 8 shall be supplemental to and not in derogation of any rights and remedies of Recipient (or its assigns) under any separate subordination agreement which Recipient (or its assigns) may at any time and from time to time enter into with Performance Guarantor.

Section 9. Termination of Performance Undertaking. Performance Guarantor’s obligations hereunder shall continue in full force and effect until the Outstanding Balance of all Eligible Receivables are finally paid and satisfied in full and the Facility Termination Date has occurred under the Receivables Purchase Agreement, provided that this Undertaking shall continue to be effective or shall be reinstated, as the case may be, if at any time payment or other satisfaction of any of the Guaranteed Obligations is rescinded or must otherwise be restored or returned upon the bankruptcy, insolvency, or reorganization of the Originator or otherwise, as though such payment had not been made or other satisfaction occurred, whether or not Recipient (or its assigns) is in possession of this Undertaking. No invalidity, irregularity or unenforceability by reason of the federal bankruptcy code or any insolvency or other similar law, or any law or order of any government or agency thereof purporting to reduce, amend or otherwise affect the Guaranteed Obligations shall impair, affect, be a defense to or claim against the obligations of Performance Guarantor under this Undertaking.

Section 10. Effect of Bankruptcy. This Performance Undertaking shall survive the insolvency of the Originator and the commencement of any case or proceeding by or against the Originator under the federal bankruptcy code or other federal, state or other applicable bankruptcy, insolvency or reorganization statutes. No automatic stay under the federal bankruptcy code with respect to the Originator or other federal, state or other applicable bankruptcy, insolvency or reorganization statutes to which the Originator is subject shall postpone the obligations of Performance Guarantor under this Undertaking.

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Section 11. Setoff. Regardless of the other means of obtaining payment of any of the Guaranteed Obligations, Recipient (and its assigns) is hereby authorized at any time and from time to time, without notice to Performance Guarantor (any such notice being expressly waived by Performance Guarantor) and to the fullest extent permitted by law, to set off and apply any deposits and other sums against the obligations of Performance Guarantor under this Undertaking, whether or not Recipient (or any such assign) shall have made any demand under this Undertaking and although such obligations may be contingent or unmatured.

Section 12. Taxes. All payments to be made by Performance Guarantor hereunder shall be made free and clear of any deduction or withholding. If Performance Guarantor is required by law to make any deduction or withholding on account of tax or otherwise from any such payment, the sum due from it in respect of such payment shall be increased to the extent necessary to ensure that, after the making of such deduction or withholding, Recipient (or its assigns) receive a net sum equal to the sum which they would have received had no deduction or withholding been made.

Section 13. Further Assurances. Performance Guarantor agrees that it will from time to time, at the request of Recipient (or its assigns), provide information relating to the business and affairs of Performance Guarantor as Recipient may reasonably request. Performance Guarantor also agrees to do all such things and execute all such documents as Recipient (or its assigns) may reasonably consider necessary or desirable to give full effect to this Undertaking and to perfect and preserve the rights and powers of Recipient hereunder.

Section 14. Successors and Assigns. This Performance Undertaking shall be binding upon Performance Guarantor, its successors and permitted assigns, and shall inure to the benefit of and be enforceable by Recipient and its successors and permitted assigns. Performance Guarantor may not assign or transfer any of its obligations hereunder without the prior written consent of each of Recipient and the Administrative Agent. Without limiting the generality of the foregoing, Recipient, solely to the extent permitted under the Agreements, may assign or otherwise transfer the Agreements, any other documents executed in connection therewith or delivered thereunder or any other agreement or note held by them evidencing, securing or otherwise executed in connection with the Guaranteed Obligations, or sell participations in any interest therein, to any other entity or other person, and such other entity or other person shall thereupon become vested, to the extent set forth in the agreement evidencing such assignment, transfer or participation, with all the rights in respect thereof granted to the Beneficiaries herein. Without limiting the generality of the foregoing sentence, the Performance Guarantor acknowledges and consents to the assignment by the Recipient, under and in connection with the Receivables Purchase Agreement, of all of the Recipient’s right, title and interest in, to and under this Undertaking to the Administrative Agent for the benefit of the Investors and the Banks party to the Receivables Purchase Agreement and the Performance Guarantor agrees that at all times that the Receivables Purchase Agreement shall be in effect (i) any claim made by the Recipient hereunder shall be deemed made for the benefit of the Administrative Agent and such Investors and Banks and (ii) any payment or remittance to be made hereunder by the Performance Guarantor in respect of any claim being made by or in respect of the Recipient or the Recipient’s interest under the Purchase Agreement shall be paid or remitted to the Administrative Agent for the benefit of such Investors and Banks.

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Section 15. Amendments and Waivers. No amendment or waiver of any provision of this Undertaking nor consent to any departure by Performance Guarantor therefrom shall be effective unless the same shall be in writing and signed by Recipient, the Administrative Agent and Performance Guarantor. No failure on the part of Recipient to exercise, and no delay in exercising, any right hereunder shall operate as a waiver thereof; nor shall any single or partial exercise of any right hereunder preclude any other or further exercise thereof or the exercise of any other right.

Section 16. Notices. All notices and other communications provided for hereunder shall be made in writing and shall be addressed as follows: if to Performance Guarantor, at the address set forth beneath its signature hereto, and if to Recipient, at the addresses set forth beneath its signature hereto, or at such other addresses as each of Performance Guarantor or any Recipient may designate in writing to the other. Each such notice or other communication shall be effective (i) if given by telecopy, upon the receipt thereof, (ii) if given by mail, three (3) Business Days after the time such communication is deposited in the mail with first class postage prepaid or (iii) if given by any other means, when received at the address specified in this Section 16.

Section 17. GOVERNING LAW. THIS UNDERTAKING SHALL BE CONSTRUED IN ACCORDANCE WITH THE INTERNAL LAWS (AND NOT THE LAW OF CONFLICTS OTHER THAN SECTION 5-1401 AND 5-1402 OF THE GENERAL OBLIGATIONS LAW WHICH THE PARTIES HERETO EXPRESSLY RELY UPON IN THE CHOICE OF SUCH LAW AS THE GOVERNING LAW HEREUNDER) OF THE STATE OF NEW YORK.

Section 18. CONSENT TO JURISDICTION. EACH OF PERFORMANCE GUARANTOR AND RECIPIENT HEREBY IRREVOCABLY SUBMITS TO THE NON-EXCLUSIVE JURISDICTION OF ANY UNITED STATES FEDERAL OR NEW YORK STATE COURT SITTING IN THE BOROUGH OF MANHATTAN IN ANY ACTION OR PROCEEDING ARISING OUT OF OR RELATING TO THIS UNDERTAKING, THE AGREEMENTS OR ANY OTHER DOCUMENT EXECUTED IN CONNECTION THEREWITH OR DELIVERED THEREUNDER AND EACH OF THE PERFORMANCE GUARANTOR AND RECIPIENT HEREBY IRREVOCABLY AGREES THAT ALL CLAIMS IN RESPECT OF SUCH ACTION OR PROCEEDING MAY BE HEARD AND DETERMINED IN ANY SUCH COURT AND IRREVOCABLY WAIVES ANY OBJECTION IT MAY NOW OR HEREAFTER HAVE AS TO THE VENUE OF ANY SUCH SUIT, ACTION OR PROCEEDING BROUGHT IN SUCH A COURT OR THAT SUCH COURT IS AN INCONVENIENT FORUM.

Section 19. Bankruptcy Petition. Performance Guarantor hereby covenants and agrees that, prior to the date that is one year and one day after the payment in full of all outstanding senior indebtedness of Recipient, it will not institute against, or join any other Person in instituting against, Recipient any bankruptcy, reorganization, arrangement, insolvency or liquidation proceedings or other similar proceeding under the laws of the United States or any state of the United States.

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Section 20. Miscellaneous. This Undertaking constitutes the entire agreement of Performance Guarantor with respect to the matters set forth herein. The rights and remedies herein provided are cumulative and not exclusive of any remedies provided by law or any other agreement, and this Undertaking shall be in addition to any other guaranty of or collateral security for any of the Guaranteed Obligations. The provisions of this Undertaking are severable, and in any action or proceeding involving any state corporate law, or any state or federal bankruptcy, insolvency, reorganization or other law affecting the rights of creditors generally, if the obligations of Performance Guarantor hereunder would otherwise be held or determined to be avoidable, invalid or unenforceable on account of the amount of Performance Guarantor’s liability under this Undertaking, then, notwithstanding any other provision of this Undertaking to the contrary, the amount of such liability shall, without any further action by Performance Guarantor or Recipient, be automatically limited and reduced to the highest amount that is valid and enforceable as determined in such action or proceeding. Any provisions of this Undertaking which are prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction. Unless otherwise specified, references herein to “Section” shall mean a reference to sections of this Undertaking.

Section 21. Amendment and Restatement; Acknowledgement. This Undertaking is an amendment and restatement of the Existing Performance Undertaking, which amendment and restatement shall not affect any rights or remedies which Recipient (or its assignees) may have under the Existing Performance Undertaking, which rights and remedies shall continue to be in full force and effect under this Undertaking.

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IN WITNESS WHEREOF, Performance Guarantor has caused this Undertaking to be executed and delivered as of the date first above written.

[Signature Page – Amended and Restated Performance Undertaking]