Exhibit 1.1

WESTLAKE CHEMICAL CORPORATION

$250,000,000

3.600% Senior Notes due 2022

UNDERWRITING AGREEMENT

JULY 10, 2012

Merrill Lynch, Pierce, Fenner & Smith Incorporated

Deutsche Bank Securities Inc.

Morgan Stanley & Co. LLC

Underwriting Agreement

July 10, 2012

MERRILL LYNCH, PIERCE, FENNER & SMITH

  INCORPORATED

DEUTSCHE BANK SECURITIES INC.

MORGAN STANLEY & CO. LLC

 As Representatives of the several Underwriters

c/o MERRILL LYNCH, PIERCE, FENNER & SMITH

        INCORPORATED

One Bryant Park

New York, NY 10036

Ladies and Gentlemen:

Introductory. Westlake Chemical Corporation, a Delaware corporation (the “ Company ”), proposes to issue and sell to the several underwriters named in Schedule A (the “ Underwriters ”), acting severally and not jointly, the respective amounts set forth in such Schedule A of $250,000,000 aggregate principal amount of the Company’s 3.600% Senior Notes due 2022 (the “ Notes ”). Merrill Lynch, Pierce, Fenner & Smith Incorporated, Deutsche Bank Securities Inc. and Morgan Stanley & Co. LLC have agreed to act as representatives of the several Underwriters (in such capacity, collectively, the “ Representatives ”) in connection with the offering and sale of the Notes.

The Notes will be issued pursuant to an indenture, dated as of January 1, 2006 (the “ Base Indenture ”), among the Company, the subsidiary guarantors party thereto and JPMorgan Chase Bank, National Association, as trustee, as amended and supplemented by that certain Sixth Supplemental Indenture, dated as of July 17, 2012, among the Company, the subsidiary guarantors party thereto (each a “ Subsidiary Guarantor ” and collectively, the “ Subsidiary Guarantors ”) and The Bank of New York Mellon Trust Company, N.A., as successor in interest to JPMorgan Chase Bank, National Association, as trustee (the “ Trustee ”). The Base Indenture as amended and supplemented by the Supplemental Indenture is referred to herein as the “ Indenture ”). The Notes will be guaranteed on a senior unsecured basis by each of the Subsidiary Guarantors pursuant to their guarantee set forth in the Indenture (each a “ Guarantee ” and collectively, the “ Guarantees ”). The Notes and the Guarantees are referred to herein collectively as the “ Securities .”

The Notes will be issued in book-entry form in the name of Cede & Co., as nominee of The Depository Trust Company (the “ Depositary ”), pursuant to a Letter of Representations, dated January 5, 2006 (the “ DTC Agreement ”), among the Company and the Depositary. The Notes, the Guarantees, the Indenture, the DTC Agreement and this Agreement are referred to herein collectively as the “ Operative Documents .”

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The Company and the Subsidiary Guarantors have prepared and filed with the Securities and Exchange Commission (the “ Commission ”) a registration statement on Form S-3 (File No. 333-177119), which contains a base prospectus (the “ Base Prospectus ”), to be used in connection with the public offering and sale of debt securities, including the Securities, and other securities of the Company under the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder (collectively, the “ Securities Act ”), and the offering thereof from time to time in accordance with Rule 415 under the Securities Act. Such registration statement, including the financial statements, exhibits and schedules thereto, in the form in which it became effective under the Securities Act, including any required information deemed to be a part thereof at the time of effectiveness pursuant to Rule 430B under the Securities Act, is called the “ Registration Statement .” The term “ Prospectus ” shall mean the final prospectus supplement relating to the Securities, together with the Base Prospectus, that is first filed pursuant to Rule 424(b) after the date and time that this Agreement is executed (the “ Execution Time ”) by the parties hereto. The term “ Preliminary Prospectus ” shall mean any preliminary prospectus supplement relating to the Securities, together with the Base Prospectus, that is first filed with the Commission pursuant to Rule 424(b). Any reference herein to the Registration Statement, the Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents that are or are deemed to be incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act prior to 2:30 p.m. on July 10, 2012 (the “ Initial Sale Time ”). All references in this Agreement to the Registration Statement, the Preliminary Prospectus, the Prospectus, or any amendments or supplements to any of the foregoing, shall include any copy thereof filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval System (“ EDGAR ”).

All references in this Agreement to financial statements and schedules and other information which is “contained,” “included” or “stated” (or other references of like import) in the Registration Statement, the Prospectus or the Preliminary Prospectus shall be deemed to mean and include all such financial statements and schedules and other information which is or is deemed to be incorporated by reference in the Registration Statement, the Prospectus or the Preliminary Prospectus, as the case may be, prior to the Initial Sale Time; and all references in this Agreement to amendments or supplements to the Registration Statement, the Prospectus or the Preliminary Prospectus shall be deemed to include the filing of any document under the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder (collectively, the “ Exchange Act ”), which is or is deemed to be incorporated by reference in the Registration Statement, the Prospectus or the Preliminary Prospectus, as the case may be, after the Initial Sale Time.

The Company and the Subsidiary Guarantors hereby confirm their agreements with the Underwriters as follows:

S ECTION  1. Representations and Warranties of the Company and the Subsidiary Guarantors.

The Company (with respect to itself and each of the Subsidiary Guarantors) and each of the Subsidiary Guarantors (with respect to itself only), jointly and severally, hereby represents, warrants and covenants to each Underwriter as of the date hereof, as of the Initial Sale Time and as of the Closing Date (in each case, a “ Representation Date ”), as follows:

a) Compliance with Registration Requirements. The Company meets the requirements for use of Form S-3 under the Securities Act. The Registration Statement has become effective under the Securities Act and no stop order suspending the effectiveness of the Registration Statement has been issued under the Securities Act and no proceedings for that purpose have been instituted or are pending or, to the best of the Company’s knowledge, are contemplated or threatened by the Commission, and any request on the part of the Commission for additional information has been complied with. In addition, the Indenture has been duly qualified under the Trust Indenture Act of 1939, as amended, and the rules and regulations promulgated thereunder (collectively, the “ Trust Indenture Act ”).

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At the respective times the Registration Statement and any post-effective amendments thereto (including the filing with the Commission of the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2011 (the “ Annual Report on Form 10-K ”)) became effective and at each Representation Date, the Registration Statement and any amendments thereto (i) complied and will comply in all material respects with the requirements of the Securities Act and the Trust Indenture Act, and (ii) did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. At the date of the Prospectus and at the Closing Date, neither the Prospectus nor any amendments or supplements thereto included or will include an untrue statement of a material fact or omitted or will omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. Notwithstanding the foregoing, the representations and warranties in this subsection shall not apply to (i) that part of the Registration Statement which constitutes the Statement of Eligibility on Form T-1 of the Trustee under the Trust Indenture Act and (ii) statements in or omissions from the Registration Statement or any post-effective amendment or the Prospectus or any amendments or supplements thereto made in reliance upon and in conformity with information furnished to the Company in writing by any of the Underwriters through the Representatives expressly for use therein, it being understood and agreed that the only such information furnished by any Underwriter through the Representatives consists of the information described as such in Section 8 hereof.

Each Preliminary Prospectus and the Prospectus, at the time each was filed with the Commission, complied in all material respects with the Securities Act, and the Preliminary Prospectus and the Prospectus delivered to the Underwriters for use in connection with the offering of the Securities will, at the time of such delivery, be identical to any electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

b) Disclosure Package. The term “ Disclosure Package ” shall mean (i) the Preliminary Prospectus dated July 10, 2012, (ii) the issuer free writing prospectuses as defined in Rule 433 of the Securities Act (each, an “ Issuer Free Writing Prospectus ”), if any, identified in Annex I hereto and (iii) any other free writing prospectus that the parties hereto shall hereafter expressly agree in writing to treat as part of the Disclosure Package. As of the Initial Sale Time, the Disclosure Package did not contain any untrue statement of a material fact or omit to state

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any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The preceding sentence does not apply to statements in or omissions from the Disclosure Package based upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives specifically for use therein.

c) Incorporated Documents . The documents incorporated or deemed to be incorporated by reference in the Registration Statement, the Preliminary Prospectus and the Prospectus (i) at the time they were or hereafter are filed with the Commission, complied or will comply in all material respects with the requirements of the Exchange Act and (ii) when read together with the other information in the Disclosure Package, at the Initial Sale Time, and when read together with the other information in the Prospectus, at the date of the Prospectus and at the Closing Date, did not or will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

d) Company is a Well-Known Seasoned Issuer . (i) At the time of filing the Registration Statement, (ii) at the time of the most recent amendment thereto for the purposes of complying with Section 10(a)(3) of the Securities Act (whether such amendment was by post-effective amendment, incorporated report filed pursuant to Section 13 or 15(d) of the Exchange Act or form of prospectus), (iii) at the time the Company or any person acting on its behalf (within the meaning, for this clause only, of Rule 163(c) of the Securities Act) made any offer relating to the Securities in reliance on the exemption of Rule 163 of the Securities Act, and (iv) as of the Execution Time, the Company was and is a “well known seasoned issuer” as defined in Rule 405 of the Securities Act. The Registration Statement is an “automatic shelf registration statement,” as defined in Rule 405 of the Securities Act, that automatically became effective not more than three years prior to the Execution Time; the Company has not received from the Commission any notice pursuant to Rule 401(g)(2) of the Securities Act objecting to use of the automatic shelf registration statement form and the Company has not otherwise ceased to be eligible to use the automatic shelf registration statement form.

e) Company is not an Ineligible Issuer . (i) At the time of filing the Registration Statement and (ii) as of the Execution Time (with such date being used as the determination date for purposes of this clause (ii)), the Company was not and is not an Ineligible Issuer (as defined in Rule 405 of the Securities Act), without taking account of any determination by the Commission pursuant to Rule 405 of the Securities Act that it is not necessary that the Company be considered an Ineligible Issuer.

f) Issuer Free Writing Prospectuses . Each Issuer Free Writing Prospectus, as of its issue date and at all subsequent times through the completion of the offering of Securities under this Agreement or until any earlier date that the Company notified or notifies the Representatives as described in the next sentence, did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, the Preliminary Prospectus or the Prospectus. If at any time following issuance of an Issuer Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the information contained in the Registration Statement, the Preliminary Prospectus or the Prospectus the Company has promptly

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notified or will promptly notify the Representatives and has promptly amended or supplemented or will promptly amend or supplement, at its own expense, such Issuer Free Writing Prospectus to eliminate or correct such conflict. The foregoing two sentences do not apply to statements in or omissions from any Issuer Free Writing Prospectus based upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives specifically for use therein.

g) Distribution of Offering Material By the Company and the Subsidiary Guarantors. The Company and the Subsidiary Guarantors have not distributed and will not distribute, prior to the later of the Closing Date and the completion of the Underwriters’ distribution of the Securities, any offering material in connection with the offering and sale of the Securities other than the Registration Statement, the Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus reviewed and consented to by the Representatives and included in Annex I hereto or any electronic road show or other written communications reviewed and consented to by the Representatives and listed on Annex II hereto (each a, “ Company Additional Written Communication ”). Each such Company Additional Written Communication, when taken together with the Disclosure Package, did not, and at the Closing Date will not, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The preceding sentence does not apply to statements in or omissions from the Company Additional Written Communication based upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives specifically for use therein.

h) No Applicable Registration or Other Similar Rights. There are no persons with registration or other similar rights to have any equity or debt securities registered for sale under the Registration Statement which have not been so registered or included in the offering contemplated by this Agreement, except for such rights as will have been duly waived prior to the Closing Date.

i) The Underwriting Agreement. This Agreement has been duly authorized, executed and delivered by the Company and the Subsidiary Guarantors.

j) Authorization of the Indenture . The Base Indenture has been duly qualified under the Trust Indenture Act and has been duly authorized, executed and delivered by the Company and the Subsidiary Guarantors party thereto and constitutes a valid and binding agreement of the Company and the Subsidiary Guarantors, enforceable against each of the Company and the Subsidiary Guarantors in accordance with its terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium, or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles. The Supplemental Indenture has been duly authorized by the Company and the Subsidiary Guarantors, and at the Closing Date, will have been duly executed and delivered by the Company and the Subsidiary Guarantors and, assuming due authorization, execution and delivery by the Trustee, will constitute a valid and binding agreement of the Company and the Subsidiary Guarantors, enforceable against each of the Company and the Subsidiary Guarantors in accordance with its terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium, or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

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k) Authorization of the Notes. The Notes to be purchased by the Underwriters from the Company are in the form contemplated by the Indenture, have been duly authorized for issuance and sale pursuant to this Agreement and the Indenture and, at the Closing Date, will have been duly executed by the Company and, assuming due authentication of the Notes by the Trustee, upon delivery to the Underwriters against payment therefore in accordance with the terms hereof, will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles, and will be entitled to the benefits of the Indenture.

l) Authorization of the Guarantees. The Guarantee by each Subsidiary Guarantor has been duly and validly authorized by such Subsidiary Guarantor and when duly endorsed on the Notes by such Subsidiary Guarantor in accordance with the terms of the Indenture and upon the due execution, authentication and delivery of the Notes in accordance with the Indenture against payment therefor in accordance with the terms hereof, will constitute valid and binding obligations of such Subsidiary Guarantor, enforceable against such Subsidiary Guarantor in accordance with its terms, except as such enforceability may be limited by bankruptcy, fraudulent conveyance or transfer, insolvency, reorganization, moratorium, and other laws relating to or affecting creditors’ rights generally and by general equitable principles.

m) Description of the Securities and the Indenture. The Notes, the Guarantees and the Indenture conform in all material respects to the descriptions thereof contained in the Disclosure Package and the Prospectus.

n) Accuracy of Statements. The statements in each of the Disclosure Package and the Prospectus under the captions “Description of the Notes”, “Description of Debt Securities”, “Description of Capital Stock” and “Certain Material U.S. Federal Tax Consequences”, in each case, insofar as such statements constitute a summary of the legal matters, documents or proceedings referred to therein, fairly present and summarize, in all material respects, the matters referred to therein.

o) No Material Adverse Change . Except as otherwise disclosed in the Disclosure Package, subsequent to the respective dates as of which information is given in the Disclosure Package, there has been no material adverse change, or any development that could reasonably be expected to result in a material adverse change, in the condition, financial or otherwise, or in the earnings, management, business, properties, results of operations, whether or not arising from transactions in the ordinary course of business, of the Company and its subsidiaries, considered as one entity (any such change is called a “ Material Adverse Change ”).

p) Independent Accountants. PricewaterhouseCoopers LLP, who have audited certain of the Company’s financial statements incorporated by reference in the Registration Statement, the Preliminary Prospectus and the Prospectus, are independent public accountants with respect to the Company as required by the Securities Act and the Exchange Act and are an independent registered public accounting firm with the Public Company Accounting Oversight Board.

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q) Incorporation and Good Standing of the Company and Subsidiary Guarantors. The Company and each Subsidiary Guarantor has been duly incorporated or formed and is an existing corporation or other entity in good standing under the laws of its state of incorporation or organization, with power and authority (corporate and other organizational) to own its properties and conduct its business as described in the Disclosure Package and the Prospectus; and the Company and each Subsidiary Guarantor is duly qualified to do business as a foreign corporation or other entity in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification, except where the failure to be so qualified or in good standing would not, individually or in the aggregate, have a material adverse effect (i) on the current or future condition (financial or other), business, properties or results of operations of the Company, the Subsidiary Guarantors and any other subsidiary of the Company, taken as a whole or (ii) on the ability of the Company and the Subsidiary Guarantors to perform their respective obligations under, and consummate the transactions contemplated by, the Operative Documents (a “Material Adverse Effect”). The Company and each of the Subsidiary Guarantors has all requisite power and authority (corporate and other organizational) to enter into the Operative Documents to which each is a party and to authorize, issue and sell the Notes and the Guarantees, as the case may be, as contemplated by this Agreement.

r) Incorporation and Good Standing of Other Subsidiaries. Each subsidiary of the Company (other than a Subsidiary Guarantor) has been duly incorporated or formed and is an existing corporation or other entity in good standing under the laws of the jurisdiction of its incorporation or organization, with power and authority (corporate and other organizational) to own its properties and conduct its business as described in the Disclosure Package and the Prospectus; and each such subsidiary is duly qualified to do business as a foreign corporation or other entity in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification, except where the failure to be so qualified or in good standing would not, individually or in the aggregate, have a Material Adverse Effect.

s) Capitalization and Other Matters. The Company has an authorized capitalization as set forth in the Disclosure Package and the Prospectus. All of the issued and outstanding shares of capital stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable. All of the issued and outstanding shares of capital stock of each Subsidiary Guarantor and of each other subsidiary of the Company has been duly authorized and validly issued and is fully paid and nonassessable and the shares of capital stock of each Subsidiary Guarantor and of each other subsidiary owned by the Company, directly or through subsidiaries, is owned free from liens, encumbrances and defects, except as (i) would not, individually or in the aggregate, have a Material Adverse Effect or (ii) disclosed in the Disclosure Package and the Prospectus.

t) No Broker or Finder’s Fee. Except as disclosed in the Disclosure Package and the Prospectus, there are no contracts, agreements or understandings between the Company or any of the Subsidiary Guarantors and any person that would give rise to a valid claim against the Company, any Subsidiary Guarantor or any Underwriter for a brokerage commission, finder’s fee or other like payment in connection with the sale of the Offered Securities.

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u) No Further Authorizations or Approvals Required. No consent, approval, authorization, or order of, or filing with, any governmental agency of the United States or body or any court with jurisdiction in the United States over the Company, any Subsidiary Guarantor or any of the respective properties is required to be obtained or made by the Company or any of the Subsidiary Guarantors for the consummation of the transactions contemplated by this Agreement in connection with the sale of the Notes, except such as have been obtained and made or will be obtained and made prior to the date hereof under the 1933 Act (provided, however, a filing with the Commission pursuant to Rule 424(b), Rule 430, Rule 430B or Rule 433 may be made after the date hereof so long as such filing is made within the time period specified in the applicable provision of such rule) and such as may be required under state securities or blue sky laws.

v) No Conflicts. The execution, delivery and performance of the Operative Documents by the Company and the Subsidiary Guarantors, and the consummation of the transactions herein contemplated, will not conflict with or result in a breach or violation of any of the terms and provisions of, or constitute a default under, (A) any statute, any rule, regulation or order of any governmental agency or body or any court, domestic or foreign, having jurisdiction over the Company, any Subsidiary Guarantor or any other subsidiary of the Company or any of their respective properties, or (B) any agreement or instrument to which the Company, any Subsidiary Guarantor or any other subsidiary of the Company is a party or by which any of them is bound or to which any of their respective properties is subject, or (C) any of their respective charters or by-laws or other organizational documents, other than, in the case of clauses (A) or (B) above, such conflicts, breaches, violations or defaults that would not, individually or in the aggregate, have a Material Adverse Effect.

w) Title to Properties. Except as disclosed in the Disclosure Package and the Prospectus, the Company, each of the Subsidiary Guarantors and each of the other subsidiaries of the Company has (A) good and indefeasible title to (in the case of fee interests in real property), (B) valid leasehold interests in (in the case of leasehold interests in real or personal property) and (C) valid title to (in the case of all other personal property), all of its respective properties and assets reflected in the Company’s consolidated financial statements included in the Registration Statement, the Disclosure Package and the Prospectus free and clear of all liens, encumbrances and defects, except for such failures to have such title to or interests in, and for such liens, encumbrances and defects, as would not, individually or in the aggregate, have a Material Adverse Effect.

x) All Necessary Permits . The Company, the Subsidiary Guarantors and each other subsidiary of the Company possess adequate certificates, authorities or permits issued by appropriate governmental agencies or bodies necessary to conduct the business now operated by them, except as would not, individually or in the aggregate, have a Material Adverse Effect, and have not received any notice of proceedings relating to the revocation or modification of any such certificate, authority or permit that, if determined adversely to the Company, the Subsidiary Guarantors or any such subsidiary, would individually or in the aggregate, have a Material Adverse Effect.

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y) Labor Matters. No labor dispute with the employees of the Company, the Subsidiary Guarantors or any other subsidiary of the Company exists or, to the knowledge of the Company or any of the Subsidiary Guarantors, is imminent that would reasonably be expected to have a Material Adverse Effect.

z) Intellectual Property Rights. The Company, the Subsidiary Guarantors and the other subsidiaries of the Company own, possess or can acquire on reasonable terms, adequate trademarks, trade names and other rights to inventions, know-how, patents, copyrights, confidential information and other intellectual property (collectively, “intellectual property rights”) necessary to conduct the business now operated by them, or presently employed by them, except as would not, individually or in the aggregate, have a Material Adverse Effect, and have not received any notice of infringement of or conflict with asserted rights of others with respect to any intellectual property rights that, if determined adversely to the Company, the Subsidiary Guarantors or any such subsidiary, would individually or in the aggregate have a Material Adverse Effect.

aa) Compliance with Environmental Laws. Except as disclosed in the Disclosure Package and the Prospectus, and except for such matters as would not, individually or in the aggregate, have a Material Adverse Effect or be required to be disclosed in the Prospectus pursuant to the Securities Act, the Company, the Subsidiary Guarantors and the other subsidiaries of the Company (or, to the knowledge of the Company or the Subsidiary Guarantors, any other entity for whose acts or omissions the Company is or the Subsidiary Guarantors are or may be liable) (1) are conducting and have conducted their businesses, operations and facilities in compliance with Environmental Laws (as defined below); (2) possess and maintain in full force and effect any and all permits, licenses or registrations required under Environmental Law for the conduct of their businesses (“Environmental Permits”); (3) have not, pursuant to any contract, assumed responsibility to cure any currently identified material liability under Environmental Law or to remediate any currently identified Hazardous Substances (as defined below) spill or release; (4) have not received any notice from a governmental authority or any other third party alleging any violation of Environmental Law or liability thereunder (including, without limitation, liability as a “potentially responsible party” and/or for costs of investigating or remediating sites containing Hazardous Substances and/or damages to natural resources); (5) are not subject to any pending or, to the knowledge of the Company or the Subsidiary Guarantors, threatened claim or other legal proceeding under any Environmental Laws against the Company or its subsidiaries; (6) do not have knowledge of any pending Environmental Law, or any unsatisfied condition in an Environmental Permit, or any release of Hazardous Substances that, individually or in the aggregate, can reasonably be expected to require any material capital expenditures to maintain the Company’s or the subsidiaries’ compliance with Environmental Law or with their Environmental Permits; and (7) does not (A) rely on any third party for an indemnity for, or the contractual assumption of, any material remediation obligation or liability under Environmental Law and (B) have reasonable cause to believe that such third party will default in its obligation to comply with such indemnity or contractual assumption. As used in this paragraph, “Environmental Laws” means any and all applicable federal, state, local, and foreign laws, statutes, ordinances, rules, regulations, requirements and common law, or any enforceable administrative or judicial interpretation, order, consent, decree or judgment thereof, relating to pollution or the protection of human health or the environment, including, without limitation, those relating to, regulating, or imposing liability or standards of conduct concerning (i) noise or

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odor, (ii) emissions, discharges, releases or threatened releases of Hazardous Substances into ambient air, surface water, groundwater or land, (iii) the generation, manufacture, processing, distribution, use, treatment, storage, disposal, release, transport or handling of, or exposure to, Hazardous Substances, (iv) the protection of wildlife or endangered or threatened species, or (v) the investigation, remediation or cleanup of, or exposure to, any Hazardous Substances. As used in this paragraph, “Hazardous Substances” means pollutants, contaminants or hazardous, dangerous or toxic substances, materials, constituents or wastes or petroleum, petroleum products and their breakdown constituents, or any other chemical substance regulated under Environmental Laws.

bb) No Undisclosed Material Action or Proceeds . Except as disclosed in the Disclosure Package and the Prospectus, there are no pending actions, suits or proceedings against or affecting the Company, the Subsidiary Guarantors, any other subsidiary of the Company or any of their respective properties that, if determined adversely to the Company, the Subsidiary Guarantors or any other subsidiary of the Company, would individually or in the aggregate have a Material Adverse Effect, or would materially and adversely affect the ability of the Company or the Subsidiary Guarantors to perform its their respective obligations under the Operative Documents, or which are otherwise material in the context of the sale of the Securities; and no such actions, suits or proceedings are threatened or, to the Company’s or any Subsidiary Guarantor’s knowledge, contemplated.

cc) Financial Statements and Financial Information . The financial statements included in the Registration Statement, the Disclosure Package and the Prospectus present fairly the financial position of the Company and its consolidated subsidiaries as of the dates shown and their results of operations and cash flows for the periods shown, and such financial statements comply as to form in all material respects with the accounting requirements of the Securities Act and have been prepared in conformity with the generally accepted accounting principles in the United States (“GAAP”) applied on a consistent basis. No other financial statements are required to be included in the Registration Statement. The summary financial information included in the Disclosure Package and the Prospectus have been derived from the financial statements included in the Disclosure Package and the Prospectus. The interactive data in eXtensible Business Reporting Language incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus fairly presents the information called for in all material respects and has been prepared in accordance with the Commission’s rules and guidelines applicable thereto. All non-GAAP financial information included in the Registration Statement complies with the requirements of Item 10 of Regulation S-K under the Securities Act.

dd) Not an Investment Company. None of the Company or any Subsidiary Guarantor is and, after giving effect to the offering and sale of the Notes and the application of the proceeds thereof as described in the Disclosure Package and the Prospectus, will be an “investment company” as defined in the Investment Company Act of 1940.

ee) Tax Law Compliance. The Company, the Subsidiary Guarantors and the other subsidiaries of the Company have filed all federal, state and local income and franchise tax returns required to be filed through the date hereof, except where the failure to so file such returns would not, individually or in the aggregate, have a Material Adverse Effect, and have paid all taxes due thereon, and other than tax deficiencies which the Company, any Subsidiary

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Guarantor or any other subsidiary of the Company is contesting in good faith and for which adequate reserves have been provided in accordance with GAAP, there is no tax deficiency that has been asserted against the Company, any Subsidiary Guarantor or any other subsidiary of the Company that would, individually or in the aggregate, have a Material Adverse Effect.

ff) No Price Stabilization or Manipulation. Prior to the date hereof, neither the Company nor any of its affiliates has taken any action which is designed to or which has constituted or which might have been expected to cause or result in unlawful stabilization or manipulation of the price of any security of the Company in connection with the offering of the Securities.

gg) Internal Controls. The Company, the Subsidiary Guarantors and the other subsidiaries of the Company maintain a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorization and (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and to maintain accountability for assets.

hh) Disclosure Controls and Procedures. The Company, the Subsidiary Guarantors and the other subsidiaries of the Company maintain disclosure controls and procedures (as defined in Rule 13a-14 of the Exchange Act) designed to ensure that information required to be disclosed by the Company, including its consolidated subsidiaries, in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported in accordance with the Exchange Act. The Company has carried out evaluations, under the supervision and with the participation of the Company’s management, of the effectiveness of the design and operation of the Company’s disclosure controls and procedures in accordance with Rule 13a-15 of the Exchange Act.

ii) Regulation T, U or X. Neither the Company nor any of its subsidiaries nor any agent thereof acting on the behalf of them has taken, and none of them will take, any action that might cause this Agreement or the issuance or sale of the Notes to violate Regulation T, Regulation U or Regulation X of the Board of Governors of the Federal Reserve System.

jj) No Change in Ratings . No “nationally recognized statistical rating organization” as such term is defined for purposes of Rule 436(g)(2) of the Securities Act (i) has imposed (or has informed the Company or any Subsidiary Guarantor that it is considering imposing) any condition (financial or otherwise) on the Company’s or any Subsidiary Guarantor’s retaining any rating assigned to the Company or any Subsidiary Guarantor or any securities of the Company or any Subsidiary Guarantor or (ii) has indicated to the Company or any Subsidiary Guarantor that it is considering (a) the downgrading, suspension, or withdrawal of, or any review for a possible change that does not indicate the direction of the possible change in, any rating so assigned or (b) any change in the outlook for any rating of the Company, any Subsidiary Guarantor or any securities of the Company or any Subsidiary Guarantor.

kk) Related Party Transactions. There are no business relationships or related-party transactions involving the Company or any subsidiary or any other person required to be described in the Preliminary Prospectus or the Prospectus that have not been described as required.

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ll) No Unlawful Contributions or Other Payments. None of the Company, any of its subsidiaries or, to the knowledge of the Company, any director, officer, agent, employee or affiliate of the Company or any of its subsidiaries is aware of or has taken any action, directly or indirectly, that would result in a violation by such persons of either (i) the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (the “ FCPA ”), including, without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA or (ii) the U.K. Bribery Act 2010 (the “ Bribery Act ”), and the Company, its subsidiaries and, to the knowledge of the Company, its affiliates have conducted their businesses in compliance with the FCPA and the Bribery Act and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith.

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

nn) No Conflict with OFAC Laws. None of the Company, any of its subsidiaries or, to the knowledge of the Company, any director, officer, agent, employee, affiliate or representative of the Company or any of its subsidiaries is an individual or entity (“ Person ”) currently the subject or target of any sanctions administered or enforced by the United States Government, including, without limitation, the U.S. Department of the Treasury’s Office of Foreign Assets Control (“ OFAC ”), the United Nations Security Council (“ UNSC ”), the European Union, Her Majesty’s Treasury (“ HMT ”), or other relevant sanctions authority (collectively, “ Sanctions ”), nor is the Company located, organized or resident in a country or territory that is the subject of Sanctions; and the Company will not directly or indirectly use the proceeds of the sale of the Notes, or lend, contribute or otherwise make available such proceeds to any subsidiaries, joint venture partners or other Person, to fund any activities of or business with any Person, or in any country or territory, that, at the time of such funding, is the subject of Sanctions or in any other manner that will result in a violation by any Person (including any Person participating in the transaction, whether as underwriter, advisor, investor or otherwise) of Sanctions.

Any certificate signed by an officer of the Company or any Subsidiary Guarantor and delivered to the Representatives or to counsel for the Underwriters in connection with the

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offering of the Securities shall be deemed to be a representation and warranty by the Company or such Subsidiary Guarantor to each Underwriter as to the matters covered thereby on the date of such certificate.

S ECTION  2. Purchase, Sale and Delivery of the Securities.

a) The Securities. The Company and the Subsidiary Guarantors agree to issue and sell to the several Underwriters, severally and not jointly, all of the Securities upon the terms herein set forth. On the basis of the representations, warranties and agreements herein contained, and upon the terms but subject to the conditions herein set forth, the Underwriters agree, severally and not jointly, to purchase from the Company and the Subsidiary Guarantors the aggregate principal amount of Notes, together with the related Guarantees, set forth opposite their names on Schedule A at a purchase price of 98.877% of the principal amount of the Notes, payable on the Closing Date.

b) The Closing Date. Delivery of certificates for the Securities in global form to be purchased by the Underwriters and payment therefor shall be made at the offices of Mayer Brown LLP, 1675 Broadway, New York, NY 10019 (or such other place as may be agreed to by the Company and the Representatives) at 9:00 a.m., New York City time, on July 17, 2012, or such other time and date as the Underwriters and the Company shall mutually agree (the time and date of such closing are called the “ Closing Date ”).

c) Public Offering of the Securities. The Representatives hereby advise the Company that the Underwriters intend to offer for sale to the public, as described in the Disclosure Package and the Prospectus, their respective portions of the Securities as soon after the Execution Time as the Representatives, in their sole judgment, have determined is advisable and practicable.

d) Payment for the Securities. Payment for and Delivery of the Securities . The Company will deliver against payment of the purchase price the Notes and the Guarantees in the form of one or more permanent global securities in definitive form (the “Global Securities”) deposited with the Trustee as custodian for The Depository Trust Company (“DTC”) and registered in the name of Cede & Co., as nominee for DTC. Payment for the Securities shall be made by the Underwriters in Federal (same day) funds by wire transfer to an account at a bank reasonably acceptable to the Underwriters specified by the Company, at 9:00 A.M., New York time, on July 17, 2012, or at such other time not later than seven full business days thereafter as the Underwriters and the Company determine, against delivery to the Trustee as custodian for DTC of the Global Securities representing all of the Offered Securities. The form of Global Securities will be made available for checking at the office of Baker Botts L.L.P., One Shell Plaza, 910 Louisiana Street, Houston, Texas 77002 at least 24 hours prior to the Closing Date.

It is understood that the Representatives have been authorized, for their own accounts and for the accounts of the several Underwriters, to accept delivery of and receipt for, and make payment of the purchase price for, the Notes that the Underwriters have agreed to purchase. The Representatives may (but shall not be obligated to) make payment for any Securities to be purchased by any Underwriter whose funds shall not have been received by the Representatives by the Closing Date for the account of such Underwriter, but any such payment shall not relieve such Underwriter from any of its obligations under this Agreement.

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S ECTION  3. Covenants of the Company and the Subsidiary Guarantors.

The Company and the Subsidiary Guarantors, jointly and severally, covenant and agree with each Underwriter as follows:

a) Compliance with Securities Regulations and Commission Requests. The Company and the Subsidiary Guarantors, subject to Section 3(b), will comply with the requirements of Rule 430B of the Securities Act, and will promptly notify the Representatives, and confirm the notice in writing, of (i) the effectiveness during the Prospectus Delivery Period (as defined below) of any post-effective amendment to the Registration Statement or the filing of any supplement or amendment to the Preliminary Prospectus or the Prospectus, (ii) the receipt of any comments from the Commission during the Prospectus Delivery Period, (iii) any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Preliminary Prospectus or the Prospectus or for additional information, and (iv) the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or of any order preventing or suspending the use of the Preliminary Prospectus or the Prospectus, or of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, or of the initiation or threatening of any proceedings for any of such purposes. The Company and the Subsidiary Guarantors will promptly effect the filings necessary pursuant to Rule 424 and will take such steps as it deems necessary to ascertain promptly whether the Preliminary Prospectus and the Prospectus transmitted for filing under Rule 424 were received for filing by the Commission and, in the event that any of them was not, it will promptly file such document. The Company and the Subsidiary Guarantors will use their reasonable best efforts to prevent the issuance of any stop order referred to above and, if any such stop order is issued, to obtain the lifting thereof at the earliest possible moment.

b) Filing of Amendments. During such period beginning on the date of this Agreement and ending on the later of the Closing Date or such date as, in the opinion of counsel for the Underwriters, the Prospectus is no longer required by law to be delivered in connection with sales of the Notes by an Underwriter or dealer, including in circumstances where such requirement may be satisfied pursuant to Rule 172 of the Securities Act (the “ Prospectus Delivery Period ”), the Company will give the Representatives notice of its intention to file or prepare any amendment to the Registration Statement (including any filing under Rule 462(b) of the Securities Act), or any amendment, supplement or revision to the Disclosure Package or the Prospectus, whether pursuant to the Securities Act, the Exchange Act or otherwise, will furnish the Representatives with copies of any such documents a reasonable amount of time prior to such proposed filing or use, as the case may be, and will not file or use any such document to which the Representatives or counsel for the Underwriters shall reasonably object.

c) Delivery of Registration Statements. The Company has furnished or will deliver to the Representatives and counsel for the Underwriters, without charge, copies of the signed copies of the Registration Statement as originally filed and of each amendment thereto (including exhibits filed therewith or incorporated by reference therein and documents incorporated or deemed to be incorporated by reference therein) and copies of the signed copies of all consents

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and certificates of experts, and will also deliver to the Representatives, without charge, a conformed copy of the Registration Statement as originally filed and of each amendment thereto (without exhibits) for each of the Underwriters. The Registration Statement and each amendment thereto furnished to the Underwriters will be identical to any electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

d) Delivery of Prospectuses. The Company will deliver to each Underwriter, without charge, as many copies of the Preliminary Prospectus as such Underwriter may reasonably request, and the Company hereby consents to the use of such copies for purposes permitted by the Securities Act. The Company will furnish to each Underwriter, without charge, during the Prospectus Delivery Period, such number of copies of the Prospectus as such Underwriter may reasonably request. The Preliminary Prospectus and the Prospectus and any amendments or supplements thereto furnished to the Underwriters will be identical to any electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

e) Continued Compliance with Securities Laws . The Company and the Subsidiary Guarantors will comply with the Securities Act and the Exchange Act so as to permit the completion of the distribution of the Securities as contemplated in this Agreement and in the Registration Statement, the Disclosure Package and the Prospectus. If at any time during the Prospectus Delivery Period, any event shall occur or condition shall exist as a result of which it is necessary, in the opinion of counsel for the Underwriters or for the Company, to amend the Registration Statement in order that the Registration Statement will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading or to amend or supplement the Disclosure Package or the Prospectus in order that the Disclosure Package or the Prospectus, as the case may be, will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at the Initial Sale Time or at the time it is delivered or conveyed to a purchaser, not misleading, or if it shall be necessary, in the opinion of either such counsel, at any such time to amend the Registration Statement or amend or supplement the Disclosure Package or the Prospectus in order to comply with the requirements of any applicable federal securities law, the Company and the Subsidiary Guarantors will (1) notify the Representatives of any such event, development or condition and (2) promptly prepare and file with the Commission, subject to Section 3(b) hereof, such amendment or supplement as may be necessary to correct such statement or omission or to make the Registration Statement, the Disclosure Package or the Prospectus comply with such law, and the Company and the Subsidiary Guarantors will furnish to the Underwriters, without charge, such number of copies of such amendment or supplement as the Underwriters may reasonably request.

f) Blue Sky Compliance. The Company and the Subsidiary Guarantors shall use their reasonable best efforts to (i) cooperate with the Representatives and counsel for the Underwriters to qualify or register the Securities for sale under (or obtain exemptions from the application of) the state securities or blue sky laws of those jurisdictions designated by the Representatives, (ii) comply with such laws and (iii) continue such qualifications, registrations and exemptions in effect so long as required for the distribution of the Securities. None of the

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Company or the Subsidiary Guarantors shall be required to qualify to transact business or to take any action that would subject it to general service of process in any such jurisdiction where it is not presently qualified or where it would be subject to taxation as a foreign business. The Company and the Subsidiary Guarantors will advise the Representatives promptly of the suspension of the qualification or registration of (or any such exemption relating to) the Securities for offering, sale or trading in any jurisdiction or any initiation or threat of any proceeding for any such purpose, and in the event of the issuance of any order suspending such qualification, registration or exemption, the Company and the Subsidiary Guarantors shall use their reasonable best efforts to obtain the withdrawal thereof at the earliest possible moment.

g) Use of Proceeds. The Company shall apply the net proceeds from the sale of the Notes sold by it in the manner described under the caption “Use of Proceeds” in the Preliminary Prospectus and the Prospectus.

h) Depositary. The Company will cooperate with the Underwriters and use its reasonable best efforts to permit the Notes to be eligible for clearance and settlement through the facilities of the Depositary.

i) Periodic Reporting Obligations. During the Prospectus Delivery Period, the Company shall file, on a timely basis, with the Commission and the NYSE all reports and documents required to be filed under the Exchange Act.

j) Agreement Not to Offer or Sell Additional Securities. During the period commencing on the date hereof and ending on the Closing Date, none of the Company or the Subsidiary Guarantors will, without the prior written consent of the Representatives (which consent may be withheld at the sole discretion of the Representatives), directly or indirectly, sell, offer, contract or grant any option to sell, pledge, transfer or establish an open “put equivalent position” within the meaning of Rule 16a-1(h) under the Exchange Act, or otherwise dispose of or transfer, or announce the offering of, or file any registration statement under the Securities Act in respect of, any debt securities of the Company or any Subsidiary Guarantor similar to the Notes or the Guarantees or securities exchangeable for or convertible into debt securities similar to the Notes or the Guarantees (other than as contemplated by this Agreement with respect to the Notes).

k) Final Term Sheet . The Company will prepare a final term sheet in a form approved by the Underwriters and attached as Exhibit B hereto, and will file such term sheet pursuant to Rule 433(d) under the Securities Act within the time required by such rule (such term sheet, the “ Final Term Sheet ”). Any such Final Term Sheet is an Issuer Free Writing Prospectus for purposes of this Agreement.

l) Permitted Free Writing Prospectuses . Each of the Company and the Subsidiary Guarantors represents that it has not made, and agrees that, unless it obtains the prior written consent of the Representatives, it will not make, any offer relating to the Securities that would constitute an Issuer Free Writing Prospectus or that would otherwise constitute a “free writing prospectus” (as defined in Rule 405 of the Securities Act) required to be filed by the Company with the Commission or retained by the Company under Rule 433 of the Securities Act; provided that the prior written consent of the Representatives shall be deemed to have been given in

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respect of any Issuer Free Writing Prospectuses included in Annex I to this Agreement. Any such free writing prospectus consented to or deemed to be consented to by the Representatives is hereinafter referred to as a “ Permitted Free Writing Prospectus .” Each of the Company and the Subsidiary Guarantors agrees that (i) it has treated and will treat, as the case may be, each Permitted Free Writing Prospectus as an Issuer Free Writing Prospectus, and (ii) has complied and will comply, as the case may be, with the requirements of Rules 164 and 433 of the Securities Act applicable to any Permitted Free Writing Prospectus, including in respect of timely filing with the Commission, legending and record keeping. Each of the Company and the Subsidiary Guarantors consents to the use by any Underwriter of a free writing prospectus that (a) is not an “issuer free writing prospectus” as defined in Rule 433, and (b) contains only (i) information describing the preliminary terms of the Notes or their offering, (ii) information permitted by Rule 134 under the Securities Act or (iii) information that describes the final terms of the Notes or their offering and that is included in the Final Term Sheet of the Company contemplated in Section 3(k).

m) Registration Statement Renewal Deadline. If immediately prior to the third anniversary (the “ Renewal Deadline ”) of the initial effective date of the Registration Statement, any of the Notes remain unsold by the Underwriters, the Company and the Subsidiary Guarantors will prior to the Renewal Deadline file, if it has not already done so and is eligible to do so, a new automatic shelf registration statement relating to the Securities, in a form satisfactory to the Representatives. If the Company is no longer eligible to file an automatic shelf registration statement, the Company and the Subsidiary Guarantors will prior to the Renewal Deadline, if it has not already done so, file a new shelf registration statement relating to the Securities, in a form satisfactory to the Representatives, and will use its reasonable best efforts to cause such registration statement to be declared effective within 60 days after the Renewal Deadline. The Company and the Subsidiary Guarantors will take all other action necessary or appropriate to permit the public offering and sale of the Securities to continue as contemplated in the expired registration statement relating to the Securities. References herein to the Registration Statement shall include such new automatic shelf registration statement or such new shelf registration statement, as the case may be.

n) Notice of Inability to Use Automatic Shelf Registration Statement Form . If at any time during the Prospectus Delivery Period, the Company receives from the Commission a notice pursuant to Rule 401(g)(2) or otherwise ceases to be eligible to use the automatic shelf registration statement form, the Company and the Subsidiary Guarantors will (i) promptly notify the Representatives, (ii) promptly file a new registration statement or post-effective amendment on the proper form relating to the Securities, in a form satisfactory to the Representatives, (iii) use its best efforts to cause such registration statement or post-effective amendment to be declared effective and (iv) promptly notify the Representatives of such effectiveness. The Company and the Subsidiary Guarantors will take all other action necessary or appropriate to permit the public offering and sale of the Securities to continue as contemplated in the registration statement that was the subject of the Rule 401(g)(2) notice or for which the Company has otherwise become ineligible. References herein to the Registration Statement shall include such new registration statement or post-effective amendment, as the case may be.

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o) Filing Fees . The Company and the Subsidiary Guarantors agree to pay the required Commission filing fees relating to the Notes within the time required by and in accordance with Rules 456(b)(1) and 457(r) of the Securities Act.

p) Compliance with Sarbanes-Oxley Act. During the Prospectus Delivery Period, the Company and the Subsidiary Guarantors will comply in all material respects with all applicable securities and other laws, rules and regulations, including, without limitation, the Sarbanes-Oxley Act, and use its reasonable best efforts to cause the directors and officers of the Company and the Subsidiary Guarantors, in their capacities as such, to comply with such laws, rules and regulations, including, without limitation, the provisions of the Sarbanes-Oxley Act.

q) No Manipulation of Price. None of the Company or the Subsidiary Guarantors will take, directly or indirectly, any action designed to cause or result in, or that has constituted or might reasonably be expected to constitute, under the Exchange Act or otherwise, the stabilization or manipulation of the price of any securities of the Company or any Subsidiary Guarantor to facilitate the sale or resale of the Securities.

The Representatives, on behalf of the several Underwriters, may, in their sole discretion, waive in writing the performance by the Company and the Subsidiary Guarantors of any one or more of the foregoing covenants or extend the time for their performance.

S ECTION  4. Payment of Expenses . The Company and the Subsidiary Guarantors, jointly and severally, agree to pay all costs, fees and expenses incurred in connection with the performance of their respective obligations hereunder and in connection with the transactions contemplated hereby, including without limitation (i) all expenses incident to the issuance and delivery of the Notes (including all printing and engraving costs), (ii) all necessary issue, transfer and other stamp taxes in connection with the issuance and sale of the Notes, (iii) all fees and expenses of the Company’s counsel, independent public or certified public accountants and other advisors to the Company and the Subsidiary Guarantors, (iv) all costs and expenses incurred in connection with the preparation, printing, filing, shipping and distribution of the Registration Statement (including financial statements, exhibits, schedules, consents and certificates of experts), each Issuer Free Writing Prospectus, the Preliminary Prospectus and the Prospectus, and all amendments and supplements thereto, and the Operative Documents, (v) all filing fees, reasonable attorneys’ fees and expenses incurred by the Company, the Subsidiary Guarantors or the Underwriters in connection with qualifying or registering (or obtaining exemptions from the qualification or registration of) all or any part of the Securities for offer and sale under the state securities or blue sky laws, and, if requested by the Representatives, preparing a “Blue Sky Survey” or memorandum, and any supplements thereto, advising the Underwriters of such qualifications, registrations and exemptions, (vi) the filing fees incident to, and the reasonable fees and expenses of counsel to the Underwriters in connection with, the review, if any, by the FINRA of the terms of the sale of the Securities, (vii) the fees and expenses of the Trustee, including the reasonable fees and expenses of counsel for the Trustee in connection with the Indenture and the Securities, (viii) any fees payable in connection with the rating of the Securities with the ratings agencies, (ix) all fees and expenses (including reasonable fees and expenses of counsel) of the Company in connection with approval of the Securities by the Depositary for “book-entry” transfer, (x) all other fees, costs and expenses referred to in Item 14 of Part II of the Registration Statement, and (xi) all other fees, costs and expenses incurred in

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connection with the performance of its obligations hereunder for which provision is not otherwise made in this Section. Except as provided in this Section 4 and Sections 6, 8 and 9 hereof, the Underwriters shall pay their own expenses, including the fees and expenses of their counsel.

S ECTION  5. Conditions of the Obligations of the Underwriters . The obligations of the several Underwriters to purchase and pay for the Notes as provided herein on the Closing Date shall be subject to the accuracy of the representations and warranties on the part of the Company and the Subsidiary Guarantors set forth in Section 1 hereof as of the date hereof, as of the Initial Sale Time, and as of the Closing Date as though then made and to the timely performance by the Company of its covenants and other obligations hereunder, and to each of the following additional conditions:

a) Effectiveness of Registration Statement . The Registration Statement shall have become effective under the Securities Act and no stop order suspending the effectiveness of the Registration Statement shall have been issued under the Securities Act and no proceedings for that purpose shall have been instituted or be pending or threatened by the Commission, any request on the part of the Commission for additional information shall have been complied with to the reasonable satisfaction of counsel to the Underwriters and the Company shall not have received from the Commission any notice pursuant to Rule 401(g)(2) of the Securities Act objecting to use of the automatic shelf registration statement form. The Preliminary Prospectus and the Prospectus shall have been filed with the Commission in accordance with Rule 424(b) (or any required post-effective amendment providing such information shall have been filed and declared effective in accordance with the requirements of Rule 430A).

b) Accountants’ Comfort Letter. On the date hereof, the Representatives shall have received from PricewaterhouseCoopers LLP, independent registered public accountants for the Company, a letter dated the date hereof addressed to the Underwriters, in form and substance satisfactory to the Representatives with respect to the audited and unaudited financial statements and certain financial information contained in the Registration Statement, the Preliminary Prospectus and the Prospectus.

c) Bring-down Comfort Letter . On the Closing Date, the Representatives shall have received from PricewaterhouseCoopers LLP, independent registered public accountants for the Company, a letter dated such date, in form and substance satisfactory to the Representatives, to the effect that they reaffirm the statements made in the letter furnished by them pursuant to subsection (b) of this Section 5, except that the specified date referred to therein for the carrying out of procedures shall be no more than three business days prior to the Closing Date.

d) No Objection. If the Registration Statement and/or the offering of the Notes has been filed with the FINRA for review, the FINRA shall not have raised any objection with respect to the fairness and reasonableness of the underwriting terms and arrangements.

e) No Material Adverse Change or Ratings Agency Change. For the period from and after the date of this Agreement and prior to the Closing Date:

(i) in the judgment of the Representatives there shall not have occurred any Material Adverse Change;

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(ii) there shall not have been any change or decrease specified in the letter or letters referred to in paragraph (c) of this Section 5 which is, in the sole judgment of the Representatives, so material and adverse as to make it impractical or inadvisable to proceed with the offering, sale or delivery of the Notes as contemplated by the Prospectus; and

(iii) there shall not have occurred any downgrading, nor shall any notice have been given of any intended or potential downgrading or of any review for a possible change that does not indicate the direction of the possible change, in the rating accorded any securities of the Company or any of its subsidiaries by any “nationally recognized statistical rating organization” as such term is defined in Section 3(a)(62) of the Exchange Act.

f) Opinion of Counsel for the Company. On the Closing Date, the Representatives shall have received the favorable opinion of Baker Botts L.L.P., counsel for the Company, dated as of such Closing Date, the form of which is attached as Exhibit A.

g) Opinion of Counsel for the Underwriters. On the Closing Date, the Representatives shall have received the favorable opinion of Mayer Brown LLP, counsel for the Underwriters, dated as of such Closing Date, with respect to such matters as may be reasonably requested by the Underwriters.

h) Officers’ Certificate. On the Closing Date, the Representatives shall have received a written certificate executed by the President or a Senior Vice President of the Company and the principal financial or accounting officer of the Company and on behalf of each Subsidiary Guarantor, dated as of such Closing Date, to the effect that:

(i) the Company has received no stop order suspending the effectiveness of the Registration Statement, and no proceedings for such purpose have been instituted or threatened by the Commission;

(ii) the Company has not received from the Commission any notice pursuant to Rule 401(g)(2) of the Securities Act objecting to use of the automatic shelf registration statement form;

(iii) the representations, warranties and covenants of the Company set forth in Section 1 of this Agreement are true and correct with the same force and effect as though expressly made on and as of such Closing Date; and

(iv) the Company has complied with all the agreements hereunder and satisfied all the conditions on its part to be performed or satisfied hereunder at or prior to such Closing Date.

i) Additional Documents . On or before the Closing Date, the Representatives and counsel for the Underwriters shall have received such information, documents and opinions as

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they may reasonably require for the purposes of enabling them to pass upon the issuance and sale of the Notes as contemplated herein, or in order to evidence the accuracy of any of the representations and warranties, or the satisfaction of any of the conditions or agreements, herein contained.

If any condition specified in this Section 5 is not satisfied when and as required to be satisfied, this Agreement may be terminated by the Representatives by notice to the Company at any time on or prior to the Closing Date, which termination shall be without liability on the part of any party to any other party, except that Sections 4, 6, 8, 9 and 17 shall at all times be effective and shall survive such termination.

S ECTION  6. Reimbursement of Underwriters’ Expenses . If this Agreement is terminated by the Representatives pursuant to Section 5, 10 or 11, or if the sale to the Underwriters of the Notes on the Closing Date is not consummated because of any refusal, inability or failure on the part of the Company or any Subsidiary Guarantor to perform any agreement herein or to comply with any provision hereof, the Company and the Subsidiary Guarantors, jointly and severally, agree to reimburse the Representatives and the other Underwriters (or such Underwriters as have terminated this Agreement with respect to themselves), severally, upon demand for all out-of-pocket expenses that shall have been reasonably incurred by the Representatives and the Underwriters in connection with the proposed purchase and the offering and sale of the Securities, including but not limited to reasonable fees and expenses of counsel, printing expenses, travel expenses, postage, facsimile and telephone charges.

S ECTION  7. Effectiveness of this Agreement . This Agreement shall not become effective until the execution of this Agreement by the parties hereto.

S ECTION  8. Indemnification .

(a) Indemnification of the Underwriters. The Company and the Subsidiary Guarantors, jointly and severally, agree to indemnify and hold harmless each Underwriter, its directors, officers, employees, affiliates and agents, and each person, if any, who controls any Underwriter within the meaning of the Securities Act and the Exchange Act against any loss, claim, damage, liability or expense, as incurred, to which such Underwriter or such director, officer, employee, affiliate, agent or controlling person may become subject, under the Securities Act, the Exchange Act or other federal or state statutory law or regulation, or at common law or otherwise (including in settlement of any litigation, if such settlement is effected with the written consent of the Company), insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based (i) upon any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or any amendment thereto, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading; or (ii) upon any untrue statement or alleged untrue statement of a material fact contained in any Company Additional Written Communication, any Issuer Free Writing Prospectus, the Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto) or any roadshow or investor presentations made to investors by the Company (whether in person or electronically) or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; and to reimburse

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each Underwriter and each such director, officer, employee, affiliate, agent and controlling person for any and all expenses (including the reasonable fees and expenses of counsel chosen by the Representatives) as such expenses are reasonably incurred by such Underwriter or such director, officer, employee, affiliate, agent or controlling person in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action; provided, however , that the foregoing indemnity agreement shall not apply to any loss, claim, damage, liability or expense to the extent, but only to the extent, arising out of or based upon any untrue statement or alleged untrue statement or omission or alleged omission made in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives expressly for use in the Registration Statement, any Company Additional Written Communication, any Issuer Free Writing Prospectus, the Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto). The indemnity agreement set forth in this Section 8(a) shall be in addition to any liabilities that the Company may otherwise have.

(b) Indemnification of the Company, the Subsidiary Guarantors and their Respective Directors and Officers. Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, each Subsidiary Guarantor and their respective directors, each of their respective officers who signed the Registration Statement and each person, if any, who controls the Company or a Subsidiary Guarantor within the meaning of the Securities Act or the Exchange Act, against any loss, claim, damage, liability or expense, as incurred, to which the Company or any such director, officer or controlling person may become subject, under the Securities Act, the Exchange Act, or other federal or state statutory law or regulation, or at common law or otherwise (including in settlement of any litigation, if such settlement is effected with the written consent of such Underwriter), insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based (i) upon any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or any amendment thereto, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading; or (ii) upon any untrue statement or alleged untrue statement of a material fact contained in any Company Additional Written Communication, any Issuer Free Writing Prospectus, the Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto) or any roadshow or investor presentations made to investors by the Company (whether in person or electronically) or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in the Registration Statement, any Company Additional Written Communication, any Issuer Free Writing Prospectus, the Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto), in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives expressly for use therein; and to reimburse the Company, or any such director, officer or controlling person for any legal and other expense reasonably incurred by the Company, or any such director, officer or controlling person in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action. The Company and the Subsidiary Guarantors hereby acknowledges that the only information furnished to the Company by any Underwriter through the Representatives expressly for use in the Registration Statement, any Company

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Additional Written Communication, any Issuer Free Writing Prospectus, the Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto) or any roadshow or investor presentations made to investors by the Company (whether in person or electronically) are the statements that will be set forth in a certificate delivered by the Representatives to the Company on the Closing Date. The indemnity agreement set forth in this Section 8(b) shall be in addition to any liabilities that each Underwriter may otherwise have.

(c) Notifications and Other Indemnification Procedures. Promptly after receipt by an indemnified party under this Section 8 of notice of the commencement of any action, such indemnified party will, if a claim in respect thereof is to be made against an indemnifying party under this Section 8, notify the indemnifying party in writing of the commencement thereof, but the omission to so notify the indemnifying party will not relieve it from any liability which it may have to any indemnified party for contribution or otherwise than under the indemnity agreement contained in this Section 8 or to the extent it is not prejudiced as a proximate result of such failure. In case any such action is brought against any indemnified party and such indemnified party seeks or intends to seek indemnity from an indemnifying party, the indemnifying party will be entitled to participate in, and, to the extent that it shall elect, jointly with all other indemnifying parties similarly notified, by written notice delivered to the indemnified party, to assume the defense thereof with counsel reasonably satisfactory to such indemnified party; provided, however, such indemnified party shall have the right to employ its own counsel in any such action and to participate in the defense thereof, but the fees and expenses of such counsel shall be at the expense of such indemnified party, unless: (i) the employment of such counsel has been specifically authorized in writing by the indemnifying party; (ii) the indemnifying party has failed promptly to assume the defense and employ counsel reasonably satisfactory to the indemnified party; or (iii) the named parties to any such action (including any impleaded parties) include both such indemnified party and the indemnifying party or any affiliate of the indemnifying party, and such indemnified party shall have reasonably concluded that either (x) there may be one or more legal defenses available to it which are different from or additional to those available to the indemnifying party or such affiliate of the indemnifying party or (y) a conflict may exist between such indemnified party and the indemnifying party or such affiliate of the indemnifying party (it being understood, however, that the indemnifying party shall not, in connection with any one such action or separate but substantially similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances, be liable for the reasonable fees and expenses of more than one separate firm of attorneys (in addition to a single firm of local counsel) for all such indemnified parties, which firm, in the case of indemnified parties described in Section 8(a), shall be designated in writing by the Representatives and that all such reasonable fees and expenses shall be reimbursed as they are incurred). Upon receipt of notice from the indemnifying party to such indemnified party of such indemnifying party’s election so to assume the defense of such action and approval by the indemnified party of counsel, the indemnifying party will not be liable to such indemnified party under this Section 8 for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof unless the indemnified party shall have employed separate counsel in accordance with the proviso to the next preceding sentence, in which case the reasonable fees and expenses of counsel shall be at the expense of the indemnifying party.

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(d) Settlements. The indemnifying party under this Section 8 shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party against any loss, claim, damage, liability or expense by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel as contemplated by Section 8(c) hereof, the indemnifying party agrees that it shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by such indemnifying party of the aforesaid request and (ii) such indemnifying party shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement, compromise or consent to the entry of judgment in any pending or threatened action, suit or proceeding in respect of which any indemnified party is or could have been a party and indemnity was or could have been sought hereunder by such indemnified party, unless such settlement, compromise or consent (i) includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such action, suit or proceeding and (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.

S ECTION  9. Contribution . If the indemnification provided for in Section 8 is for any reason held to be unavailable to or otherwise insufficient to hold harmless an indemnified party in respect of any losses, claims, damages, liabilities or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount paid or payable by such indemnified party, as incurred, as a result of any losses, claims, damages, liabilities or expenses referred to therein (i) in such proportion as is appropriate to reflect the relative benefits received by the Company and the Subsidiary Guarantors, on the one hand, and the Underwriters, on the other hand, from the offering of the Securities pursuant to this Agreement or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company and the Subsidiary Guarantors, on the one hand, and the Underwriters, on the other hand, in connection with the statements or omissions which resulted in such losses, claims, damages, liabilities or expenses, as well as any other relevant equitable considerations. The relative benefits received by the Company and the Subsidiary Guarantors, on the one hand, and the Underwriters, on the other hand, in connection with the offering of the Notes pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the offering of the Securities pursuant to this Agreement (before deducting expenses) received by the Company, and the total underwriting discount received by the Underwriters, in each case as set forth on the front cover page of the Prospectus bear to the aggregate initial public offering price of the Securities as set forth on such cover. The relative fault of the Company and the Subsidiary Guarantors, on the one hand, and the Underwriters, on the other hand, shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company or the Subsidiary Guarantors, on the one hand, or the Underwriters, on the other hand, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

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The amount paid or payable by a party as a result of the losses, claims, damages, liabilities and expenses referred to above shall be deemed to include, subject to the limitations set forth in Section 8(c), any reasonable legal or other fees or expenses reasonably incurred by such party in connection with investigating or defending any action or claim.

The Company, the Subsidiary Guarantors and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 9 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to in this Section 9.

Notwithstanding the provisions of this Section 9, no Underwriter shall be required to contribute any amount in excess of the underwriting commissions received by such Underwriter in connection with the Notes underwritten by it and distributed to the public. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute pursuant to this Section 9 are several, and not joint, in proportion to their respective underwriting commitments as set forth opposite their names in Schedule A. For purposes of this Section 9, each director, officer, employee, affiliate and agent of an Underwriter and each person, if any, who controls an Underwriter within the meaning of the Securities Act and the Exchange Act shall have the same rights to contribution as such Underwriter, and each director of the Company or any Subsidiary Guarantors, each officer of the Company or any Subsidiary Guarantor who signed the Registration Statement, and each person, if any, who controls the Company or any Subsidiary Guarantor within the meaning of the Securities Act and the Exchange Act shall have the same rights to contribution as the Company and a Subsidiary Guarantor.

S ECTION  10. Default of One or More of the Several Underwriters . If, on the Closing Date, any one or more of the several Underwriters shall fail or refuse to purchase Notes that it or they have agreed to purchase hereunder on such date, and the aggregate principal amount of Notes, which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase does not exceed 10% of the aggregate principal amount of the Notes to be purchased on such date, the other Underwriters shall be obligated, severally, in the proportion to the aggregate principal amounts of such Notes set forth opposite their respective names on Schedule A bears to the aggregate principal amount of such Notes set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as may be specified by the Representatives with the consent of the non-defaulting Underwriters, to purchase such Notes which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date. If, on the Closing Date, any one or more of the Underwriters shall fail or refuse to purchase such Notes and the aggregate principal amount of such Notes with respect to which such default occurs exceeds 10% of the aggregate principal amount of Notes to be purchased on such date, and arrangements satisfactory to the Representatives and the Company for the purchase of such Notes are not made within 48 hours after such default, this Agreement shall terminate without liability of any party to any other party except that the provisions of Sections 4, 6, 8, 9 and 17 shall at all times be effective and shall survive such termination. In any such case, either the Representatives or the Company shall have the right to postpone the Closing Date, but in no event for longer than seven days in order that the required changes, if any, to the Registration Statement, any Issuer Free Writing Prospectus, the Preliminary Prospectus or the Prospectus or any other documents or arrangements may be effected.

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As used in this Agreement, the term “Underwriter” shall be deemed to include any person substituted for a defaulting Underwriter under this Section 10. Any action taken under this Section 10 shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

S ECTION  11. Termination of this Agreement . Prior to the Closing Date, this Agreement may be terminated by the Representatives by notice given to the Company if at any time (i) trading or quotation in any of the Company’s securities shall have been suspended or limited by the Commission or the NYSE, or trading in securities generally on either the Nasdaq Stock Market or the NYSE shall have been suspended or limited, or minimum or maximum prices shall have been generally established on any of such stock exchanges by the Commission or the FINRA; (ii) a general banking moratorium shall have been declared by federal or New York banking authorities; (iii) there shall have occurred any outbreak or escalation of national or international hostilities or any crisis or calamity involving the United States, or any change in the United States or international financial markets, or any substantial change or development involving a prospective substantial change in United States’ or international political, financial or economic conditions, as in the judgment of the Representatives is material and adverse and makes it impracticable or inadvisable to market the Notes in the manner and on the terms described in the Disclosure Package or the Prospectus or to enforce contracts for the sale of securities; (iv) in the judgment of the Representatives there shall have occurred any Material Adverse Change; or (v) there shall have occurred a material disruption in commercial banking or securities settlement or clearance services. Any termination pursuant to this Section 11 shall be without liability of any party to any other party except as provided in Sections 4 and 6 hereof, and provided further that Sections 4, 6, 8, 9 and 17 shall survive such termination and remain in full force and effect.

S ECTION  12. No Fiduciary Duty . Each of the Company and the Subsidiary Guarantors acknowledges and agrees that: (i) the purchase and sale of the Notes pursuant to this Agreement, including the determination of the public offering price of the Notes and any related discounts and commissions, is an arm’s-length commercial transaction between the Company and the Subsidiary Guarantors, on the one hand, and the several Underwriters, on the other hand, and each of the Company and the Subsidiary Guarantors is capable of evaluating and understanding and understands and accepts the terms, risks and conditions of the transactions contemplated by this Agreement; (ii) in connection with each transaction contemplated hereby and the process leading to such transaction each Underwriter is and has been acting solely as a principal and is not the financial advisor, agent or fiduciary of the Company or any Subsidiary Guarantor or their affiliates, stockholders, creditors or employees or any other party; (iii) no Underwriter has assumed or will assume an advisory, agency or fiduciary responsibility in favor of the Company or any Subsidiary Guarantor with respect to any of the transactions contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company or any Subsidiary Guarantor on other matters) and no Underwriter has any obligation to the Company or any Subsidiary Guarantor with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement; (iv) the several Underwriters and their respective affiliates may be engaged in a broad range of transactions that

26

involve interests that differ from those of the Company and the Subsidiary Guarantors and that the several Underwriters have no obligation to disclose any of such interests by virtue of any advisory, agency or fiduciary relationship; and (v) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company and the Subsidiary Guarantors have consulted their own legal, accounting, regulatory and tax advisors to the extent they deemed appropriate.

This Agreement supersedes all prior agreements and understandings (whether written or oral) between the Company and the Subsidiary Guarantors and the several Underwriters with respect to the subject matter hereof. The Company and the Subsidiary Guarantors hereby waive and release, to the fullest extent permitted by law, any claims that they may have against the several Underwriters with respect to any breach or alleged breach of agency or fiduciary duty.

S ECTION  13. Representations and Indemnities to Survive Delivery . The respective indemnities, agreements, representations, warranties and other statements of the Company and the Subsidiary Guarantors, of their officers and of the several Underwriters set forth in or made pursuant to this Agreement (i) will remain operative and in full force and effect, regardless of any (A) investigation, or statement as to the results thereof, made by or on behalf of any Underwriter, the officers or employees of any Underwriter, or any person controlling the Underwriter, the Company, any Subsidiary Guarantor, the officers or employees of the Company and the Subsidiary Guarantors, or any person controlling the Company or any Subsidiary Guarantor, as the case may be or (B) acceptance of the Notes and payment for them hereunder and (ii) will survive delivery of and payment for the Notes sold hereunder and any termination of this Agreement.

S ECTION  14. Notices . All communications hereunder shall be in writing and shall be mailed, hand delivered or telecopied and confirmed to the parties hereto as follows:

If to the Representatives:

Merrill Lynch, Pierce, Fenner & Smith

  Incorporated

One Bryant Park

NY1-100-18-03

New York, NY 10036

Facsimile: 646-855-5958

Attention: High Grade Transaction Management/Legal

Deutsche Bank Securities Inc.

60 Wall Street

New York, NY 10005

Facsimile: 212-469-4877

Attention: Debt Capital Markets Syndicate

with a copy to: General Counsel (Fax: 212-797-4561

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Morgan Stanley & Co. LLC

1585 Broadway

New York, NY 10036

Facsimile: 212-507-8999

Attention: Investment Banking Division

with a copy to:

Mayer Brown LLP

1675 Broadway

New York, New York 10019

Facsimile: (212) 849 5552

Attention: Edward Best

       John P. Berkery

If to the Company:

Westlake Chemical Corporation

2801 Post Oak Boulevard

Houston, Texas 77056

Facsimile: (713) 629-6239

Attention: General Counsel

with a copy to:

Baker Botts L.L.P.

910 Louisiana Street

Houston, Texas 77002

Facsimile: (713) 229-7784

Attention: Timothy S. Taylor

Any party hereto may change the address for receipt of communications by giving written notice to the others.

S ECTION  15. Successors . This Agreement will inure to the benefit of and be binding upon the parties hereto, including any substitute Underwriters pursuant to Section 10 hereof, and to the benefit of the directors, officers, employees, affiliates, agents and controlling persons referred to in Sections 8 and 9, and in each case their respective successors, and no other person will have any right or obligation hereunder. The term “successors” shall not include any purchaser of the Notes as such from any of the Underwriters merely by reason of such purchase.

S ECTION  16. Partial Unenforceability . The invalidity or unenforceability of any Section, paragraph or provision of this Agreement shall not affect the validity or enforceability of any other Section, paragraph or provision hereof. If any Section, paragraph or provision of this Agreement is for any reason determined to be invalid or unenforceable, there shall be deemed to be made such minor changes (and only such minor changes) as are necessary to make it valid and enforceable.

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S ECTION  17. Governing Law Provisions . THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF NEW YORK APPLICABLE TO AGREEMENTS MADE AND TO BE PERFORMED IN THAT STATE.

(a) Consent to Jurisdiction. Any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby (“ Related Proceedings ”) may be instituted in the federal courts of the United States of America located in the City and County of New York, Borough of Manhattan, or the courts of the State of New York in each case located in the City and County of New York, Borough of Manhattan (collectively, the “ Specified Courts ”), and each party irrevocably submits to the exclusive jurisdiction (except for proceedings instituted in regard to the enforcement of a judgment of any such court (a “ Related Judgment ”), as to which such jurisdiction is non-exclusive) of such courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail to such party’s address set forth above shall be effective service of process for any suit, action or other proceeding brought in any such court. The parties irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any such court that any such suit, action or other proceeding brought in any such court has been brought in an inconvenient forum.

Section 18. Research Analyst Independence . The Company and the Subsidiary Guarantors acknowledge that the Underwriters’ research analysts and research departments are required to be independent from their respective investment banking divisions and are subject to certain regulations and internal policies, and that such Underwriters’ research analysts may hold views and make statements or investment recommendations and/or publish research reports with respect to the Company, its subsidiaries and/or the offering of the Securities that differ from the views of their respective investment banking divisions. The Company and the Subsidiary Guarantors hereby waive and release, to the fullest extent permitted by applicable law, any claims that the Company or any Subsidiary Guarantor may have against the Underwriters with respect to any conflict of interest that may arise from the fact that the views expressed by their independent research analysts and research departments may be different from or inconsistent with the views or advice communicated to the Company or any Subsidiary Guarantor by such Underwriters’ investment banking divisions. The Company and the Subsidiary Guarantors acknowledge that each of the Underwriters is a full service securities firm and as such from time to time, subject to applicable securities laws, may effect transactions for its own account or the account of its customers and hold long or short positions in debt or equity securities of the companies that may be the subject of the transactions contemplated by this Agreement.

S ECTION  19. General Provisions . This Agreement may be executed in two or more counterparts, each one of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. This Agreement may not be amended or modified unless in writing by all of the parties hereto, and no condition herein (express or implied) may be waived unless waived in writing by each party whom the condition is meant to benefit. The Section headings herein are for the convenience of the parties only and shall not affect the construction or interpretation of this Agreement.

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Each of the parties hereto acknowledges that it is a sophisticated business person who was adequately represented by counsel during negotiations regarding the provisions hereof, including, without limitation, the indemnification provisions of Section 8 and the contribution provisions of Section 9, and is fully informed regarding said provisions. Each of the parties hereto further acknowledges that the provisions of Sections 8 and 9 hereto fairly allocate the risks in light of the ability of the parties to investigate the Company, its affairs and its business in order to assure that adequate disclosure has been made in the Registration Statement, the Disclosure Package and the Prospectus (and any amendments and supplements thereto), as required by the Securities Act and the Exchange Act.

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If the foregoing is in accordance with your understanding of our agreement, kindly sign and return to the Company the enclosed copies hereof, whereupon this instrument, along with all counterparts hereof, shall become a binding agreement in accordance with its terms.

[Signature Page to Underwriting Agreement]

SUBSIDIARY GUARANTORS :

[Signature Page to Underwriting Agreement]

[Signature Page to Underwriting Agreement]

The foregoing Underwriting Agreement is hereby confirmed and accepted by the Representatives as of the date first above written.

[Signature Page to Underwriting Agreement]

Sch-1

ANNEX I

Issuer Free Writing Prospectuses

Final Term Sheet dated July 10, 2012

Annex-1

ANNEX II

Company Additional Written Communication

Electronic (Netroadshow) road show of the Company used in connection the offering of the Notes

Annex-2

EXHIBIT A-1

[Form of Opinion of Baker Botts L.L.P.]

(i) The Company has been duly incorporated and is an existing corporation in good standing under the laws of the State of Delaware, with corporate power and authority to own its properties and conduct its business as described in the Disclosure Package and the Prospectus.

(ii) The Company has the requisite corporate power and authority (A) to enter into the Operative Documents and (B) to authorize, issue and sell the Notes as contemplated by this Agreement.

(iii) The Notes have been duly authorized and executed by the Company and, when authenticated in accordance with the terms of the Indenture and delivered to and paid for by the Underwriters in accordance with the terms hereof, will be the valid and legally binding obligations of the Company, enforceable against the Company in accordance with their terms except as such enforceability may be limited by bankruptcy, fraudulent conveyance or transfer, insolvency, reorganization, moratorium and other laws relating to or affecting creditors’ rights generally and by general equitable principles (regardless of whether such enforceability is considered in a proceeding in equity or at law).

(iv) When the Guarantees have been duly authorized and executed by the Subsidiary Guarantors and the Notes to which such Guarantees have been endorsed have been duly authenticated by the Trustee in accordance with the terms of the Indenture and delivered to and paid for by the Underwriters in accordance with the terms hereof, the Guarantees will be valid and legally binding obligations of the Subsidiary Guarantors, enforceable against each of the Subsidiary Guarantors in accordance with their respective terms except as such enforceability may be limited by bankruptcy, fraudulent conveyance or transfer, insolvency, reorganization, moratorium and other laws relating to or affecting creditors’ rights generally and by general equitable principles (regardless of whether such enforceability is considered in a proceeding in equity or at law).

(v) The Indenture has been duly authorized, executed and delivered by the Company and, assuming the due authorization, execution and delivery thereof by the Subsidiary Guarantors and the Trustee, is a valid and legally binding obligation of the Company and each of the Subsidiary Guarantors, enforceable against the Company and each of the Subsidiary Guarantors in accordance with its terms except as such enforceability may be limited by bankruptcy, fraudulent conveyance or transfer, insolvency, reorganization, moratorium and other laws relating to or affecting creditors’ rights generally and by general equitable principles (regardless of whether such enforceability is considered in a proceeding in equity or at law).

(vi) The Indenture has been duly qualified under the Trust Indenture Act.

(vii) The Notes, the Guarantees and the Indenture conform in all material respects to the description thereof in the Disclosure Package and the Prospectus.

A-1

(viii) The statements in the Preliminary Prospectus and the Prospectus under the caption “Material U.S. Federal Tax Consequences” insofar as they constitute statements of United States federal income tax law or legal conclusions with respect thereto, fairly summarize the matters referred to therein in all material respects.

(ix) Except as described in the Disclosure Package and the Prospectus, there are no contracts or agreements known to such counsel between the Company or any Subsidiary Guarantor and any person granting such person the right to require the Company or such Subsidiary Guarantor to file a registration statement under the Securities Act with respect to any securities of the Company or such Subsidiary Guarantor owned or to be owned by such person or to require the Company or such Subsidiary Guarantor to include such securities in the securities registered pursuant to the Registration Statement that have not been validly waived or satisfied.

(x) No consent, approval, authorization or order of, or filing with, any governmental agency or body or any court is required to be obtained or made by the Company or any Subsidiary Guarantor for the consummation of the transactions contemplated by the Operative Documents in connection with the sale of the Notes and the Guarantees, except such as have been obtained and made under the Securities Act, such consents, approvals or filings as may be required by or with the FINRA (as to which such counsel need express no opinion) and such as may be required under state securities or blue sky laws (as to which such counsel need express no opinion).

(xi) The execution, delivery and performance of the Operative Documents and the sale of the Notes and the Guarantees, in each case by the Company and the Subsidiary Guarantors, will not conflict with or result in a breach or violation of any of the terms and provisions of, or constitute a default under, (A) any statute, rule or regulation of, or order of any governmental agency or body or any court having jurisdiction over the Company and the Subsidiary Guarantors in the United States of America, the State of Texas or the State of New York, or the Delaware General Corporation Law, the Delaware Uniform Limited Partnership Act or the Delaware Limited Liability Company Act (provided, however, that such counsel need express no opinion with respect to compliance with any state securities or antifraud law, rule or regulation), (B) any agreement or instrument listed as an exhibit to the most recently filed Annual Report on Form 10-K of the Company (the “Material Agreements”), or (C) the charter and by-laws of the Company, other than, in the case of clauses (A) or (B) above, such conflicts, breaches, violations or defaults that would not, individually or in the aggregate, have a Material Adverse Effect.

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

(xiii) The Registration Statement is an “automatic shelf registration statement,” as defined in Rule 405 of the Securities Act, that automatically became effective not more than three years prior to the Execution Time; the Preliminary Prospectus and the Prospectus were each filed with the Commission pursuant to the subparagraph of Rule 424(b) specified in such opinion, and, to the knowledge of such counsel, no stop order suspending the effectiveness of the Registration Statement or any part thereof or order suspending or preventing the use of the Prospectus, Preliminary Prospectus or any Issuer Free Writing Prospectus has been issued and no proceedings for that purpose have been instituted or are pending or contemplated under the Securities Act.

A-2

(xv) None of the Company or any of the Subsidiary Guarantors is, and after receipt of payment for the Notes and the application of the proceeds thereof as contemplated under the caption “Use of Proceeds” in the Disclosure Package and the Prospectus will be, required to register as an “investment company” within the meaning of the Investment Company Act.

Such counsel shall also include, in a separate paragraph of its opinion letter, statements to the following effect:

We have reviewed the Registration Statement, the Disclosure Package and the Prospectus and have participated in conferences with officers and other representatives of the Company, with representatives of the Company’s independent registered public accounting firm and with your representatives and your counsel, at which the contents of the Registration Statement, the Disclosure Package, the Prospectus and related matters were discussed. The purpose of our professional engagement was not to establish or confirm factual matters set forth in the Registration Statement, the Disclosure Package or the Prospectus, and we have not undertaken to verify independently any of the factual matters in such documents. Moreover, many of the determinations required to be made in the preparation of the Registration Statement, the Disclosure Package and the Prospectus involve matters of a non-legal nature. Accordingly, we are not passing upon, and do not assume any responsibility for, the accuracy, completeness or fairness of the statements contained or included in the Registration Statement, the Disclosure Package and the Prospectus (except to the extent stated in paragraphs (vii) and (viii) above). Subject to the foregoing and on the basis of the information we gained in the course of performing the services referred to above, we advise you that:

(a) the Registration Statement, as of the latest Effective Time with respect to the Underwriters, the Preliminary Prospectus, as of the Applicable Time, and the Prospectus, as of its date and the date hereof, appear on their face to be appropriately responsive in all material respects to the requirements of the Securities Act and the rules and regulations of the Commission thereunder; and

(b) nothing came to our attention that caused us to believe that:

(1) the Registration Statement, as of the latest Effective Time with respect to the Underwriters, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading,

(2) the Disclosure Package, as of the Applicable Time, included an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, or

(3) the Prospectus, as of its date or as of the date hereof, included or includes an untrue statement of a material fact or omitted or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

A-3

it being understood that in each case we have not been asked to, and do not, express any belief with respect to (a) the financial statements and schedules or other financial, accounting or statistical information contained or included or incorporated by reference therein or omitted therefrom, (b) representations and warranties and other statements of fact contained in the exhibits to the Registration Statement or to documents incorporated by reference therein or (c) that part of the Registration Statement that constitutes the Form T-1

A-4

EXHIBIT A-2

[Form of Opinion of In-House Counsel]

(i) Each Subsidiary Guarantor has been duly incorporated or formed and is an existing corporation or other entity in good standing under the laws of the jurisdiction of its incorporation or organization, with power and authority (corporate and other organizational) to own its properties and conduct its business as described in the Disclosure Package and the Prospectus.

(ii) Each of the Company and the Subsidiary Guarantors is duly qualified to do business as a foreign corporation or other entity in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification, except where the failure to be so qualified or in good standing would not, individually or in the aggregate, have a Material Adverse Effect.

(iii) Each Subsidiary Guarantor has the requisite corporate or other organizational power and authority (A) to enter into the Operative Documents to which each is a party and (B) to authorize and issue its respective Guarantee as contemplated by this Agreement.

(iv) Each Subsidiary Guarantor has duly authorized, executed and delivered the Underwriting Agreement, the Indenture and its respective Guarantee.

(v) To such counsel’s knowledge, there is no litigation or governmental proceedings by or against the Company or any subsidiary of the Company or concerning any property of the Company or any of its subsidiaries, pending or threatened, that (A) could reasonably be expected to have a Material Adverse Effect if adversely determined or (B) is required to be disclosed in the Registration Statement, the Prospectus or the Disclosure Package and are not so disclosed, other than, in each of clauses (A) and (B), as disclosed in the Disclosure Package and the Prospectus.

(vi) To such counsel’s knowledge, there are no franchises, contracts or documents which are required to be described in the Registration Statement, the Disclosure Package, the Prospectus or the documents incorporated by reference therein or to be filed as exhibits to the Registration Statement which have not been so described and filed as required.

(vii) The Company has an authorized capitalization as set forth in the Disclosure Package and the Prospectus; all of the issued and outstanding shares of capital stock or other ownership interests, as the case may be, of each Subsidiary Guarantor and of each other subsidiary of the Company has been duly authorized and validly issued and are fully paid and nonassessable; and the shares of capital stock or other ownership interests, as the case may be, of each Subsidiary Guarantor and of each other subsidiary owned by the Company, directly or through subsidiaries, is owned free from liens, encumbrances and defects, except as (i) would not, individually or in the aggregate, have a Material Adverse Effect or (ii) disclosed in the Disclosure Package and the Prospectus;

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(viii) The execution, delivery and performance of the Operative Documents by the Company and the Subsidiary Guarantors to which each is a party will not result in (A) a breach or violation of any of the terms and provisions of, or constitute a default under, the charter or by-laws or other organizational documents of any Subsidiary Guarantor or any other subsidiary of the Company, or (B) any agreement or instrument to which the Company, any Subsidiary Guarantor or any other subsidiary of the Company is a party or by which any of them is bound or to which any of their respective properties is subject (excluding the Material Agreements, as to which such counsel need express no opinion), other than, in the case of clause (B) above, such conflicts, breaches, violations or defaults that would not, individually or in the aggregate, have a Material Adverse Effect; and

(ix) The documents incorporated by reference in the Disclosure Package and the Prospectus, at the time they were filed with the Commission, appear on their faces to comply as to form in all material respects with the requirements of the Exchange Act; it being understood that such counsel has not been asked to, and do not, express any belief with respect to (a) the financial statements and schedules or other financial, accounting or statistical information contained or included or incorporated by reference therein or omitted therefrom and (b) representations and warranties and other statements of fact contained in the exhibits to the documents incorporated by reference in the Disclosure Package.

Such counsel shall also include, in a separate paragraph of its opinion, statements to the following effect:

Such counsel has reviewed the Registration Statement, the Disclosure Package and the Prospectus and has participated in conferences with other officers and representatives of the Company, with representatives of the Company’s independent registered public accounting firm and the Company’s counsel and with your representatives and your counsel, at which the contents of the Registration Statement, the Disclosure Package, the Prospectus and related matters were discussed. The purpose of such counsel’s professional engagement was not to establish or confirm factual matters set forth in the Registration Statement, the Disclosure Package or the Prospectus, and such counsel has not undertaken to verify independently any of the factual matters in such documents. Moreover, many of the determinations required to be made in the preparation of the Registration Statement, the Disclosure Package and the Prospectus involve matters of a non-legal nature. Accordingly, such counsel is not passing upon, and does not assume any responsibility for, the accuracy, completeness or fairness of the statements contained or included in the Registration Statement, the Disclosure Package and the Prospectus. Subject to the foregoing and on the basis of the information such counsel gained in the course of performing the services referred to above, such counsel advises you that nothing came to such counsel’s attention that caused him to believe that:

(1) the Registration Statement, as of the latest Effective Time with respect to the Underwriters, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading,

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(2) the Disclosure Package, as of the Applicable Time, included an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, or

(3) the Prospectus, as of its date or as of the date hereof, included or includes an untrue statement of a material fact or omitted or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

it being understood that in each case such counsel has not been asked to, and do not, express any belief with respect to (a) the financial statements and schedules or other financial, accounting or statistical information contained or included or incorporated by reference therein or omitted therefrom, (b) representations and warranties and other statements of fact contained in the exhibits to the Registration Statement or to documents incorporated by reference therein or (c) that part of the Registration Statement that constitutes the Form T-1.

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EXHIBIT B

WESTLAKE CHEMICAL CORPORATION

Form of Final Term Sheet

Free Writing Prospectus

(To Prospectus dated September 30, 2011 and

Preliminary Prospectus Supplement dated July 10, 2012)

$250,000,000

Westlake Chemical Corporation

3.600% Senior Notes due 2022

Final Term Sheet

July 10, 2012

The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, the issuer or any underwriter participating in this offering can arrange to send you the prospectus supplement and accompanying prospectus if you request it by calling Deutsche Bank Securities Inc. toll-free at (800) 503-4611, Morgan Stanley & Co. LLC toll-free at (866) 718-1649 or Merrill Lynch, Pierce, Fenner & Smith Incorporated toll-free at (800) 294-1322.

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