UNDERWRITING AGREEMENT

Exhibit 1.1

ENTERPRISE PRODUCTS OPERATING LLC

$400,000,000 5.65% Senior Notes due 2013

$700,000,000 6.50% Senior Notes due 2019

UNDERWRITING AGREEMENT

March 31, 2008

Lehman Brothers Inc.
Citigroup Global Markets Inc.
J.P. Morgan Securities Inc.
Scotia Capital (USA) Inc.
As Representatives of the several
Underwriters named in Schedule I attached hereto,

c/o Lehman Brothers Inc.
745 Seventh Avenue
New York, New York 10019

Ladies and Gentlemen:

     Enterprise Products Operating LLC, a Texas limited liability company (the “ Operating LLC ”), proposes to issue and sell to the underwriters listed on Schedule I hereto (collectively, the “ Underwriters ”) $400,000,000 aggregate principal amount of the Operating LLC’s 5.65% Senior Notes due 2013 and $700,000,000 aggregate principal amount of the Operating LLC’s 6.50% Senior Notes due 2019 (collectively, the “ Notes ”), as set forth on Schedule I hereto, to be fully and unconditionally guaranteed on a senior unsecured basis by Enterprise Products Partners L.P., a Delaware limited partnership (the “ Partnership ”) (the “ Guarantees ,” together with the Notes, the “ Securities ”).

     The Securities are to be issued under the Indenture dated as of October 4, 2004 among the Operating LLC (as successor to Enterprise Products Operating L.P.), as issuer, the Partnership, as parent guarantor, and Wells Fargo Bank, N.A., as trustee (the “ Trustee ”) (collectively, as amended and supplemented by the Tenth Supplemental Indenture, dated as of June 30, 2007, providing for the Operating LLC as the successor issuer to Enterprise Products Operating L.P., the “ Base Indenture ”), and the Twelfth Supplemental Indenture and the Thirteenth Supplemental Indenture, each to be dated as of the Delivery Date (such Twelfth Supplemental Indenture and Thirteenth Supplemental Indenture, collectively, the “ Supplemental Indentures ”) (the Base Indenture, as amended and supplemented as of the Delivery Date, the “ Indenture ”).

     This is to confirm the agreement among the Partnership, Enterprise Products OLPGP, Inc., a Delaware corporation (the “ OLPGP ”), and the Operating LLC (collectively with the

Partnership and the OLPGP, the “ Enterprise Parties ”), and the Underwriters concerning the purchase of the Securities from the Partnership and the Operating LLC by the Underwriters.

     1.  Representations, Warranties and Agreements of the Enterprise Parties . Each of the Enterprise Parties jointly and severally represents and warrants to, and agrees with, the Underwriters that:

     (a) A registration statement on Form S-3 (File No. 333-145709) relating to the Securities (i) has been prepared by the Partnership and the Operating LLC pursuant to the requirements of the Securities Act of 1933, as amended (the “ Securities Act ”), and the rules and regulations (the “ Rules and Regulations ”) of the Securities and Exchange Commission (the “ Commission ”) thereunder; (ii) has been filed with the Commission under the Securities Act; and (iii) is effective under the Securities Act. Copies of such registration statement and any amendment thereto have been made available by the Partnership and the Operating LLC to you as the representatives (the “ Representatives ”) of the Underwriters. As used in this Agreement:

     (i) “ Applicable Time ” means 5:20 p.m. (New York City time) on the date of this Agreement;

     (ii) “ Base Prospectus ” means the base prospectus included in the Registration Statement at the Applicable Time;

     (ii) “ Effective Date ” means any date as of which any part of such registration statement relating to the Securities became, or is deemed to have become, effective under the Securities Act in accordance with the Rules and Regulations (including, for the avoidance of doubt, any effective date with respect to the Underwriters);

     (iii) “ Issuer Free Writing Prospectus ” means each “free writing prospectus” (as defined in Rule 405 of the Rules and Regulations) or “issuer free writing prospectus” (as defined in Rule 433 of the Rules and Regulations) prepared by or on behalf of the Partnership or the Operating LLC or used or referred to by the Partnership or the Operating LLC in connection with the offering of the Securities;

     (iv) “ Preliminary Prospectus ” means any preliminary prospectus relating to the Securities included in such registration statement or filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations, including the Base Prospectus and any preliminary prospectus supplement thereto relating to the Securities;

     (v) “ Pricing Disclosure Package ” means (i) the Base Prospectus, (ii) the Preliminary Prospectus as amended or supplemented as of the Applicable Time, (iii) the Issuer Free Writing Prospectuses, if any, identified in Schedule II hereto, and (iv) the final term sheet attached as Schedule IV hereto.

     (vi) “ Prospectus ” means the final prospectus relating to the Securities, including the Base Prospectus and any prospectus supplement thereto relating to the Securities, as filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations; and

     (vii) “ Registration Statement ” means, collectively, the various parts of the registration statement referred to in this Section 1(a), each as amended as of the Effective Date for such part, including any Preliminary Prospectus or the Prospectus and all exhibits to such registration statement.

Any reference to any Preliminary Prospectus, the Pricing Disclosure Package or the Prospectus shall be deemed to refer to and include any documents incorporated by reference therein pursuant to Form S-3 under the Securities Act as of the date of such Preliminary Prospectus or the Prospectus, as the case may be, or in the case of the Pricing Disclosure Package, as of the Applicable Time. Any reference to the “ most recent Preliminary Prospectus ” shall be deemed to refer to the latest Preliminary Prospectus included in the Registration Statement or filed pursuant to Rule 424(b) on or prior to the date hereof. Any reference to any amendment or supplement to any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any document filed under the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), after the date of such Preliminary Prospectus or the Prospectus, as the case may be, and incorporated by reference in such Preliminary Prospectus or the Prospectus, as the case may be; and any reference to any amendment to the Registration Statement shall be deemed to include the most recent annual report of the Partnership on Form 10-K filed with the Commission pursuant to Section 13(a) or 15(d) of the Exchange Act after the original Effective Date that is incorporated by reference in the Registration Statement. The Commission has not issued any order preventing or suspending the use of any Preliminary Prospectus or the Prospectus or suspending the effectiveness of the Registration Statement, and no proceeding or examination for such purpose has been instituted or, to the Partnership’s knowledge, threatened by the Commission. The Commission has not notified the Partnership or the Operating LLC of any objection to the use of the form of the Registration Statement.

     (b)  Well-Known Seasoned Issuer and Not an Ineligible Issuer . Each of the Partnership and the Operating LLC were at the time of the initial filing of the Registration Statement and continue to be a “well-known seasoned issuers” (as defined in Rule 405 under the Securities Act) eligible to use an “automatic shelf registration statement” (as defined in Rule 405 under the Securities Act) for the registration of the Securities, including not having been an “ineligible issuer” (as defined in Rule 405 under the Securities Act) at any such time or date. Neither the Partnership nor the Operating LLC has received from the Commission any notice pursuant to Rule 401(g)(2) under the Securities Act objecting to the use of the automatic shelf registration statement form. The Registration Statement is not the subject of a pending proceeding or examination under Section 8(d) or 8(e) of the Securities Act, and neither the Partnership nor the Operating LLC is the subject of a pending proceeding under Section 8A of the Securities Act in connection with the offering of the Securities.

     (c)  Form of Documents. The Registration Statement conformed and will conform in all material respects on each Effective Date and on the Delivery Date, and any amendment to the Registration Statement filed after the date hereof will conform in all material respects when filed, to the requirements of the Securities Act and the Rules and Regulations. The most recent Preliminary Prospectus conformed, and the Prospectus will conform, in all material respects when filed with the Commission pursuant to Rule 424(b) to the requirements of the Securities Act and the Rules and Regulations. The documents incorporated by reference in any Preliminary Prospectus or the Prospectus conformed, and any further documents so incorporated will

conform, when filed with the Commission, in all material respects to the requirements of the Exchange Act or the Securities Act, as applicable, and the rules and regulations of the Commission thereunder. The Registration Statement and the Prospectus conform in all material respects to the requirements applicable to them under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”).

     (d)  Registration Statement. The Registration Statement did not, as of each Effective Date, 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; provided that no representation or warranty is made as to information contained in or omitted from the Registration Statement in reliance upon and in conformity with written information furnished to the Partnership and the Operating LLC through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information is specified in Section 8(b).

     (e)  Prospectus. The Prospectus will not, as of its date and on the Delivery Date, contain 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; provided that no representation or warranty is made as to information contained in or omitted from the Prospectus in reliance upon and in conformity with written information furnished to the Partnership and the Operating LLC through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information is specified in Section 8(b).

     (f)  Documents Incorporated by Reference. The documents incorporated by reference in any Preliminary Prospectus or the Prospectus did not, and any further documents filed and incorporated by reference therein will not, when filed with the Commission, contain 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.

     (g)  Pricing Disclosure Package. The Pricing Disclosure Package did not, as of the Applicable Time, contain 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; provided that no representation or warranty is made as to information contained in or omitted from the Pricing Disclosure Package in reliance upon and in conformity with written information furnished to the Partnership and the Operating LLC through the Representatives by or on behalf of any Underwriters specifically for inclusion therein, which information is specified in Section 8(b).

     (h)  Issuer Free Writing Prospectus and Pricing Disclosure Package. Each Issuer Free Writing Prospectus (including, without limitation, any road show that is a free writing prospectus under Rule 433), when considered together with the Pricing Disclosure Package as of the Applicable Time, did not contain 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; provided that no representation or warranty is made as to information contained in or omitted from any Issuer Free Writing Prospectus in reliance upon and in conformity with written information furnished to the Partnership and the

Operating LLC through the Representatives by or on behalf of any Underwriters specifically for inclusion therein, which information is specified in Section 8(b).

     (i)  Each Issuer Free Writing Prospectus . Each Issuer Free Writing Prospectus conformed or will conform in all material respects to the requirements of the Securities Act and the Rules and Regulations on the date of first use, and the Partnership has complied with any filing requirements applicable to such Issuer Free Writing Prospectus pursuant to the Rules and Regulations. Neither the Partnership nor the Operating LLC has made any offer relating to the Securities that would constitute an Issuer Free Writing Prospectus without the prior written consent of the Representatives, except as set forth on Schedule IV hereto. The Partnership and the Operating LLC have retained in accordance with the Rules and Regulations all Issuer Free Writing Prospectuses that were not required to be filed pursuant to the Rules and Regulations (it being understood that, as of the date hereof, the Partnership and the Operating LLC have not retained any Issuer Free Writing Prospectus for the three-year period required thereby). Each Issuer Free Writing Prospectus does not and will not include any information that conflicts with the information contained in the Registration Statement or the Pricing Disclosure Package, including any document incorporated therein and any prospectus supplement deemed to be a part thereof that has not been superseded or modified. The foregoing sentence does not apply to statements in or omissions from any Issuer Free Writing Prospectus based upon and in conformity with written information furnished to the Partnership and the Operating LLC by the Underwriters through the Representatives specifically for inclusion therein, which information consists solely of the information specified in Section 8(b).

     (j)  Formation and Qualification of the Partnership Entities . Each of Enterprise Products GP, LLC, a Delaware limited liability company (the “ General Partner ”), the Partnership, the OLPGP, the Operating LLC and their respective subsidiaries listed on Schedule III hereto (each, a “ Partnership Entity ” and collectively, the “ Partnership Entities, ” and the subsidiaries of the Partnership listed on Schedule III hereto, the “ Subsidiaries ”) has been duly formed or incorporated, as the case may be, and is validly existing in good standing under the laws of its respective jurisdiction of formation or incorporation, as the case may be, with all corporate, limited liability company or partnership, as the case may be, power and authority necessary to own or hold its properties and conduct the businesses in which it is engaged and, in the case of the General Partner and the OLPGP, to act as general partner of the Partnership and managing member of the Operating LLC, respectively, in each case in all material respects as described in the Registration Statement, the Pricing Disclosure Package and the Prospectus. Each Partnership Entity is duly registered or qualified to do business and is in good standing as a foreign corporation, limited liability company or limited partnership, as the case may be, in each jurisdiction in which its ownership or lease of property or the conduct of its businesses requires such qualification or registration, except where the failure to so qualify or register would not, individually or in the aggregate, have a material adverse effect on the condition (financial or otherwise), results of operations, business or prospects of the Partnership Entities taken as a whole (a “ Material Adverse Effect ”) or subject the limited partners of the Partnership to any material liability or disability.

     (k)  Ownership of General Partner . Enterprise GP Holdings L.P., a Delaware limited partnership (“ EPE ”), owns 100% of the issued and outstanding membership interests in the General Partner; such membership interests have been duly authorized and validly issued in

accordance with the limited liability company agreement of the General Partner, as amended and/or restated on or prior to the date hereof (the “ GP LLC Agreement ”); and EPE owns such membership interests free and clear of all liens, encumbrances, security interests, equities, charges or claims other than those in favor of lenders of EPE.

     (l)  Ownership of General Partner Interest in the Partnership . The General Partner is the sole general partner of the Partnership with a 2.0% general partner interest in the Partnership (including the right to receive Incentive Distributions (as defined in the Partnership Agreement) (the “ Incentive Distribution Rights ”)); such general partner interest has been duly authorized and validly issued in accordance with the agreement of limited partnership of the Partnership, as amended and/or restated on or prior to the date hereof (the “ Partnership Agreement ”); and the General Partner owns such general partner interest free and clear of all liens, encumbrances, security interests, equities, charges or claims.

     (m)  Ownership of the OLPGP . The Partnership owns 100% of the issued and outstanding capital stock in the OLPGP; such capital stock has been duly authorized and validly issued in accordance with the bylaws of the OLPGP, as amended or restated on or prior to the date hereof (the “ OLPGP Bylaws ”), and the certificate of incorporation of the OLPGP, as amended and restated on or prior to the date hereof (the “ OLPGP Certificate of Incorporation ”), and is fully paid and non-assessable; and the Partnership owns such capital stock free and clear of all liens, encumbrances, security interests, equities, charges or claims.

     (n)  Ownership of Operating LLC . The OLPGP owns 0.001% of the membership interests in the Operating LLC and the Partnership owns 99.999% of the membership interests in the Operating LLC; such membership interests have been duly authorized and validly issued in accordance with the agreement of limited liability company agreement of the Operating LLC, as amended and/or restated on or prior to the date hereof (the “ Operating LLC Agreement ”) and are fully paid and non-assessable (except as such non-assessability may be affected by Section 18-607 of the Delaware LLC Act); and the OLPGP and the Partnership own such membership interests free and clear of all liens, encumbrances, security interests, equities, charges or claims.

     (o)  No Registration Rights . Neither the filing of the Registration Statement nor the offering of the Securities as contemplated by this Agreement gives rise to any rights for or relating to the registration of any securities of the Partnership, the Operating LLC or any of their Subsidiaries, except such rights as have been waived.

     (p)  Authority . Each of the Enterprise Parties has all requisite power and authority to execute and deliver this Agreement and to perform its respective obligations hereunder, and the Partnership and the Operating LLC have all requisite power and authority to execute and deliver the Base Indenture and the Supplemental Indentures and to perform their respective obligations thereunder. The Partnership and the Operating LLC have all requisite power and authority to issue, sell and deliver the Guarantees and the Notes, respectively, in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, the Operating LLC Agreement, the Indenture, the Registration Statement, the Pricing Disclosure Package and Prospectus. All action required to be taken by the Enterprise Parties or any of their security holders, partners or members for (i) the due and proper authorization, execution and delivery of this Agreement and the Indenture, (ii) the authorization, issuance, sale and delivery of the

Securities and (iii) the consummation of the transactions contemplated hereby and thereby has been duly and validly taken.

     (q)  Ownership of Subsidiaries . All of the outstanding shares of capital stock, partnership interests or membership interests, as the case may be, of each Subsidiary have been duly and validly authorized and issued, and are fully paid and non-assessable (except as such non-assessability may be affected by Section 17-607 of the Delaware LP Act, in the case of partnership interests, or Section 18-607 of the Delaware LLC Act, in the case of membership interests, and except as otherwise disclosed in the Pricing Disclosure Package and the Prospectus). Except as described in the Pricing Disclosure Package and the Prospectus, the Partnership and the Operating LLC, as the case may be, directly or indirectly, owns the shares of capital stock, partnership interests or membership interests in each Subsidiary as set forth on Schedule III hereto free and clear of all liens, encumbrances (other than contractual restrictions on transfer contained in the applicable constituent documents), security interests, equities, charges, claims or restrictions upon voting or any other claim of any third party. None of the Enterprise Parties has any subsidiaries other than as set forth on Schedule III hereto that, individually or in the aggregate, would be deemed to be a “ significant subsidiary ” as such term is defined in Rule 405 of the Securities Act.

     (r)  Authorization, Execution and Delivery of Agreement . This Agreement has been duly authorized and validly executed and delivered by each of the Enterprise Parties.

     (s)  Authorization, Execution and Enforceability of Agreements . (i) The GP LLC Agreement has been duly authorized, executed and delivered by EPE and is a valid and legally binding agreement of EPE, enforceable against EPE in accordance with its terms, (ii) the Partnership Agreement has been duly authorized, executed and delivered by the General Partner and is a valid and legally binding agreement of the General Partner, enforceable against the General Partner in accordance with its terms; and (iii) the Operating LLC Agreement has been duly authorized, executed and delivered by each of the OLPGP and the Partnership and is a valid and legally binding agreement of each of the OLPGP and the Partnership, enforceable against each of the OLPGP and the Partnership in accordance with its terms; provided that, with respect to each such agreement listed in this Section (s)(i)-(iii), the enforceability thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws relating to or affecting creditors’ rights generally and by general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law).

     (t)  Enforceability of Indenture. The Base Indenture has been duly authorized, executed and delivered by (i) the Partnership and (ii) the predecessor of the Operating LLC and the Operating LLC, as applicable. Each of the Supplemental Indentures has been duly authorized, executed and delivered by each of the Partnership and the Operating LLC. The execution and delivery of, and the performance by the Operating LLC and the Partnership of their respective obligations under the Indenture have been duly and validly authorized by each of the Operating LLC and the Partnership. The Indenture, assuming due authorization, execution and delivery thereof by the Trustee, when executed and delivered by the Operating LLC and the Partnership, will constitute a valid and legally binding agreement of the Operating LLC and the Partnership, enforceable against the Operating LLC and the Partnership in accordance with its terms; provided that, the enforceability thereof may be limited by bankruptcy, insolvency,

fraudulent transfer, reorganization, moratorium and similar laws relating to or affecting creditors’ rights generally and by general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law). The Indenture is duly qualified under the Trust Indenture Act.

     (u)  Valid Issuance of the Notes. The Notes have been duly authorized for issuance and sale to the Underwriters, and, when executed by the Operating LLC and authenticated by the Trustee in accordance with the provisions of the Indenture and delivered to and paid for by the Underwriters in accordance with the terms of this Agreement, will have been duly executed and delivered by the Operating LLC, and will constitute the valid and legally binding obligations of the Operating LLC entitled to the benefits of the Indenture and enforceable against the Operating LLC in accordance with their terms; provided that, the enforceability thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws relating to or affecting creditors’ rights generally and by general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law).

     (v)  Valid Issuance of the Guarantees. The Guarantees by the Partnership have been duly authorized by the General Partner on behalf of the Partnership and, on the Delivery Date, will have been duly executed and delivered by the Partnership; when the Notes have been issued, executed and authenticated in accordance with the Indenture and delivered to and paid for by the Underwriters in accordance with the terms of this Agreement, the Guarantees will constitute the valid and legally binding obligations of the Partnership entitled to the benefits of the Indenture and will be enforceable against the Partnership in accordance with their terms; provided that, the enforceability thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws relating to or affecting creditors’ rights generally and by general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law).

     (w)  No Conflicts or Violations. None of the (i) offering, issuance and sale by the Operating LLC and the Partnership of the Securities, (ii) the execution, delivery and performance of this Agreement, the Indenture and the Securities by the Enterprise Parties that are parties hereto or thereto, or (iii) consummation of the transactions contemplated hereby and thereby (A) conflicts or will conflict with or constitutes or will constitute a violation of the certificate of limited partnership or agreement of limited partnership, certificate of formation or limited liability company agreement, certificate or articles of incorporation or bylaws or other organizational documents of any of the Partnership Entities, (B) conflicts or will conflict with or constitutes or will constitute a breach or violation of, or a default (or an event that, with notice or lapse of time or both, would constitute such a default) under, any indenture, mortgage, deed of trust, loan agreement, lease or other agreement or instrument to which any of the Partnership Entities is a party or by which any of them or any of their respective properties or assets may be bound, (C) violates or will violate any statute, law or regulation or any order, judgment, decree or injunction of any court, arbitrator or governmental agency or body having jurisdiction over any of the Partnership Entities or any of their respective properties or assets, or (D) results or will result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of any of the Partnership Entities, which conflicts, breaches, violations, defaults or liens, in the case of clauses (B) or (D) , would, individually or in the aggregate, have a Material Adverse Effect.

     (x)  No Consents. No permit, consent, approval, authorization, order, registration, filing or qualification (“ consent ”) of or with any court, governmental agency or body having jurisdiction over the Partnership Entities or any of their respective properties is required in connection with (i) the offering, issuance and sale by the Operating LLC and the Partnership of the Securities in the manner contemplated in this Agreement and in the Registration Statement, the Pricing Disclosure Package and the Prospectus, (ii) the execution, delivery and performance of this Agreement, the Indenture and the Securities by the Enterprise Parties that are parties thereto or (iii) the consummation by the Enterprise Parties of the transactions contemplated by this Agreement, the Indenture and the Securities, except for (A) such consents required under the Securities Act, the Exchange Act, the Trust Indenture Act (all of which have been obtained) and state securities or Blue Sky laws in connection with the purchase and distribution of the Securities by the Underwriters and (B) such consents that have been, or prior to the Delivery Date (as defined herein) will be, obtained.

     (y)  No Default . None of the Partnership Entities is (i) in violation of its certificate of limited partnership or agreement of limited partnership, certificate of formation or limited liability company agreement, certificate or articles of incorporation or bylaws or other organizational documents, (ii) in violation of any law, statute, ordinance, administrative or governmental rule or regulation applicable to it or of any order, judgment, decree or injunction of any court or governmental agency or body having jurisdiction over it or has failed to obtain any license, permit, certificate, franchise or other governmental authorization or permit necessary to the ownership of its property or to the conduct of its business, or (iii) in breach, default (and no event that, with notice or lapse of time or both, would constitute such a default has occurred or is continuing) or violation in the performance of any obligation, agreement or condition contained in any bond, debenture, note or any other evidence of indebtedness or in any agreement, indenture, lease or other instrument to which it is a party or by which it or any of its properties may be bound, which breach, default or violation, in the case of clause (ii) or (iii), would, if continued, have a Material Adverse Effect, or could materially impair the ability of any of the Partnership Entities to perform their obligations under this Agreement or the Base Indenture together with the Supplemental Indentures.

     (z)  Independent Registered Public Accounting Firm . Deloitte & Touche LLP, who has audited the audited financial statements contained or incorporated by reference in the Registration Statement, the Pricing Disclosure Package and the Prospectus, is an independent registered public accounting firm with respect to the Partnership and the General Partner within the meaning of the Securities Act and the applicable rules and regulations thereunder adopted by the Commission and the Public Company Accounting Oversight Board (United States) (the “ PCAOB ”).

     (aa)  Financial Statements . The historical financial statements (including the related notes and supporting schedule) contained or incorporated by reference in the Registration Statement, the Pricing Disclosure Package and the Prospectus (i) comply in all material respects with the applicable requirements under the Securities Act and the Exchange Act (except that certain supporting schedules are omitted), (ii) present fairly in all material respects the financial position, results of operations and cash flows of the entities purported to be shown thereby on the basis stated therein at the respective dates or for the respective periods, and (iii) have been prepared in accordance with accounting principles generally accepted in the United States of

America consistently applied throughout the periods involved, except to the extent disclosed therein. The other financial information of the General Partner and the Partnership and its subsidiaries, including non-GAAP financial measures, if any, contained or incorporated by reference in the Registration Statement, the Pricing Disclosure Package and the Prospectus has been derived from the accounting records of the General Partner, the Partnership and its subsidiaries, and fairly presents the information purported to be shown thereby. Nothing has come to the attention of any of the Partnership Entities that has caused them to believe that the statistical and market-related data included in the Registration Statement, the most recent Preliminary Prospectus and the Prospectus is not based on or derived from sources that are reliable and accurate in all material respects.

     (bb)  No Distribution of Other Offering Materials . None of the Partnership Entities has distributed or, prior to the completion of the distribution of the Securities, will distribute, any offering material in connection with the offering and sale of the Securities other than the Registration Statement, any Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus to which the Representatives have consented in accordance with Section 1(i), 5(b) or 5(l) and the Issuer Free Writing Prospectus set forth on Schedule IV hereto and any other materials, if any, permitted by the Securities Act, including Rule 134 of the Rules and Regulations.

     (cc)  Conformity to Description of the Securities . The Securities, when issued and delivered against payment therefor as provided in this Agreement and in the Indenture, will conform in all material respects to the descriptions thereof contained or incorporated by reference in the Registration Statement, the Pricing Disclosure Package and the Prospectus.

     (dd)  Certain Transactions . Except as disclosed in the Prospectus and the Pricing Disclosure Package, subsequent to the respective dates as of which such information is given in the Registration Statement and the Pricing Disclosure Package, (i) none of the Partnership Entities has incurred any liability or obligation, indirect, direct or contingent, or entered into any transactions, not in the ordinary course of business, that, individually or in the aggregate, is material to the Partnership Entities, taken as a whole, and (ii) there has not been any material change in the capitalization or material increase in the long-term debt of the Partnership Entities, or any dividend or distribution of any kind declared, paid or made by the Partnership on any class of its partnership interests.

     (ee)  No Omitted Descriptions; Legal Descriptions . There are no legal or governmental proceedings pending or, to the knowledge of the Enterprise Parties, threatened or contemplated, against any of the Partnership Entities, or to which any of the Partnership Entities is a party, or to which any of their respective properties or assets is subject, that are required to be described in the Registration Statement, the Pricing Disclosure Package or the Prospectus but are not described as required, and there are no agreements, contracts, indentures, leases or other instruments that are required to be described in the Registration Statement, the Pricing Disclosure Package or the Prospectus or to be filed as an exhibit to the Registration Statement that are not described or filed as required by the Securities Act or the Rules and Regulations or the Exchange Act or the rules and regulations thereunder. The statements included in or incorporated by reference into the Registration Statement, the Pricing Disclosure Package and the Prospectus under the headings “Description of the Notes,” “Description of Debt Securities,”

“Certain ERISA Considerations” and “Material U.S. Tax Consequences,” insofar as such statements summarize legal matters, agreements, documents or proceedings discussed therein, are accurate and fair summaries of such legal matters, agreements, documents or proceedings.

     (ff)  Title to Properties . Each Partnership Entity has (i) good and indefeasible title to all its interests in its properties that are material to the operations of the Partnership Entities, taken as a whole, and (ii) good and marketable title in fee simple to, or valid rights to lease or otherwise use, all items of other real and personal property which are material to the business of the Partnership Entities, in each case free and clear of all liens, encumbrances, claims and defects and imperfections of title except such as (A) do not materially affect the value of such property and do not materially interfere with the use made and proposed to be made of such property by the Partnership Entities, (B) could not reasonably be expected to have a Material Adverse Effect or (C) are described, and subject to the limitations contained, in the Pricing Disclosure Package.

     (gg)  Rights-of-Way . Each of the Partnership Entities has such consents, easements, rights-of-way or licenses from any person (“ rights-of-way ”) as are necessary to conduct its business in the manner described in the Pricing Disclosure Package and the Prospectus, subject to such qualifications as may be set forth in the Pricing Disclosure Package and the Prospectus and except for such rights-of-way the failure of which to have obtained would not have, individually or in the aggregate, a Material Adverse Effect; each of the Partnership Entities has fulfilled and performed all its material obligations with respect to such rights-of-way and no event has occurred which allows, or after notice or lapse of time would allow, revocation or termination thereof or would result in any impairment of the rights of the holder of any such rights-of-way, except for such revocations, terminations and impairments that will not have a Material Adverse Effect, subject in each case to such qualification as may be set forth in the Pricing Disclosure Package and the Prospectus; and, except as described in the Pricing Disclosure Package and the Prospectus, none of such rights-of-way contains any restriction that is materially burdensome to the Partnership Entities, taken as a whole.

     (hh)  Permits . Each of the Partnership Entities has such permits, consents, licenses, franchises, certificates and authorizations of governmental or regulatory authorities (“ permits ”) as are necessary to own or lease its properties and to conduct its business in the manner described in the Pricing Disclosure Package and the Prospectus, subject to such qualifications as may be set forth in the Pricing Disclosure Package and the Prospectus and except for such permits that, if not obtained, would not have, individually or in the aggregate, a Material Adverse Effect; each of the Partnership Entities has fulfilled and performed all its material obligations with respect to such permits in the manner described, and subject to the limitations contained in the Pricing Disclosure Package and the Prospectus, and no event has occurred that would prevent the permits from being renewed or reissued or that allows, or after notice or lapse of time would allow, revocation or termination thereof or results or would result in any impairment of the rights of the holder of any such permit, except for such non-renewals, non-issues, revocations, terminations and impairments that would not, individually or in the aggregate, have a Material Adverse Effect. None of the Partnership Entities has received notification of any revocation or modification of any such permit or has any reason to believe that any such permit will not be renewed in the ordinary course.

     (ii)  Books and Records; Accounting Controls . The Partnership Entities (i) make and keep books, records and accounts that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of assets, and (ii) maintain systems of internal accounting controls sufficient to provide reasonable assurances that (A) transactions are executed in accordance with management’s general or specific authorization; (B) transactions are recorded as necessary to permit preparation of financial statements in conformity with accounting principles generally accepted in the United States of America and to maintain accountability for assets; (C) access to assets is permitted only in accordance with management’s general or specific authorization; and (D) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

     (jj)  Related Party Transactions . No relationship, direct or indirect, exists between or among the Partnership Entities on the one hand, and the directors, officers, partners, customers or suppliers of the General Partner and its affiliates (other than the Partnership Entities) on the other hand, which is required to be described in the Pricing Disclosure Package and the Prospectus and which is not so described.

     (kk)  Environmental Compliance . There has been no storage, generation, transportation, handling, treatment, disposal or discharge of any kind of toxic or other wastes or other hazardous substances by any of the Partnership Entities (or, to the knowledge of the Enterprise Parties, any other entity (including any predecessor) for whose acts or omissions any of the Partnership Entities is or could reasonably be expected to be liable) at, upon or from any of the property now or previously owned or leased by any of the Partnership Entities or upon any other property, in violation of any statute or any ordinance, rule, regulation, order, judgment, decree or permit or which would, under any statute or any ordinance, rule (including rule of common law), regulation, order, judgment, decree or permit, give rise to any liability, except for any violation or liability that could not reasonably be expected to have, individually or in the aggregate with all such violations and liabilities, a Material Adverse Effect; and there has been no disposal, discharge, emission or other release of any kind onto such property or into the environment surrounding such property of any toxic or other wastes or other hazardous substances with respect to which any of the Enterprise Parties has knowledge, except for any such disposal, discharge, emission or other release of any kind which could not reasonably be expected to have, individually or in the aggregate with all such discharges and other releases, a Material Adverse Effect.

     (ll)  Insurance . The Partnership Entities maintain insurance covering their properties, operations, personnel and businesses against such losses and risks as are reasonably adequate to protect them and their businesses in a manner consistent with other businesses similarly situated. Except as disclosed in the Pricing Disclosure Package and the Prospectus, none of the Partnership Entities has received notice from any insurer or agent of such insurer that substantial capital improvements or other expenditures will have to be made in order to continue such insurance; all such insurance is outstanding and duly in force on the date hereof and will be outstanding and duly in force on the Delivery Date.

     (mm)  Litigation . There are no legal or governmental proceedings pending to which any Partnership Entity is a party or of which any property or assets of any Partnership Entity is the subject that, individually or in the aggregate, if determined adversely to such Partnership Entity,

could reasonably be expected to have a Material Adverse Effect; and to the knowledge of the Enterprise Parties, no such proceedings are threatened or contemplated by governmental authorities or threatened by others.

     (nn)  No Labor Disputes . No labor dispute with the employees that are engaged in the business of the Partnership or its subsidiaries exists or, to the knowledge of the Enterprise Parties, is imminent or threatened that is reasonably likely to result in a Material Adverse Effect.

     (oo)  Intellectual Property . Each Partnership Entity owns or possesses adequate rights to use all material patents, patent applications, trademarks, service marks, trade names, trademark registrations, service mark registrations, copyrights, licenses and know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures) necessary for the conduct of their respective businesses; and the conduct of their respective businesses will not conflict in any material respect with, and no Partnership Entity has received any notice of any claim of conflict with, any such rights of others.

     (pp)  Investment Company . None of the Partnership Entities is now, or after sale of the Securities to be sold by the Partnership and the Operating LLC hereunder and application of the net proceeds from such sale as described in the most recent Preliminary Prospectus under the caption “Use of Proceeds” will be, an “ investment company ” or a company “ controlled by ” an “ investment company ” within the meaning of the Investment Company Act of 1940, as amended (the “ Investment Company Act ”).

     (qq)  Absence of Certain Actions . No action has been taken and no statute, rule, regulation or order has been enacted, adopted or issued by any governmental agency or body which prevents the issuance or sale of the Securities in any jurisdiction; no injunction, restraining order or order of any nature by any federal or state court of competent jurisdiction has been issued with respect to any Partnership Entity which would prevent or suspend the issuance or sale of the Securities or the use of the Pricing Disclosure Package in any jurisdiction; no action, suit or proceeding is pending against or, to the knowledge of the Enterprise Parties, threatened against or affecting any Partnership Entity before any court or arbitrator or any governmental agency, body or official, domestic or foreign, which could reasonably be expected to interfere with or adversely affect the issuance of the Securities or in any manner draw into question the validity or enforceability of this Agreement or the Indenture or any action taken or to be taken pursuant hereto or thereto; and the Partnership and the Operating LLC have complied with any and all requests by any securities authority in any jurisdiction for additional information to be included in the most recent Preliminary Prospectus.

     (rr)  No Stabilizing Transactions . None of the General Partner, the Partnership, the Operating LLC or any of their affiliates has taken, directly or indirectly, any action designed to or which has constituted or which would reasonably be expected to cause or result, under the Exchange Act or otherwise, in stabilization or manipulation of the price of any securities of the Partnership or the Operating LLC to facilitate the sale or resale of the Securities.

     (ss)  Form S-3 . The conditions for the use of Form S-3 by the Partnership and the Operating LLC, as set forth in the General Instructions thereto, have been satisfied.

     (tt)  Disclosure Controls . The General Partner and the Partnership have established and maintain disclosure controls and procedures (as such term is defined in Rule 13a-15(e) and 15d-15(e) under the Exchange Act) which (i) are designed to ensure that material information relating to the Partnership, including its consolidated subsidiaries, is made known to the General Partner’s principal executive officer and its principal financial officer by others within those entities, particularly during the periods in which the periodic reports required under the Exchange Act are being prepared; (ii) have been evaluated for effectiveness as of the end of the period covered by the Partnership’s most recent annual report filed with the Commission; and (iii) are effective in achieving reasonable assurances that the Partnership’s desired control objectives as described in Item 9A of the Partnership’s Annual Report on Form 10-K for the period ended December 31, 2007 (the “ 2007 Annual Report ”) have been met.

     (uu)  No Deficiency in Internal Controls . Based on the evaluation of its internal controls and procedures conducted in connection with the preparation and filing of the 2007 Annual Report, neither the Partnership nor the General Partner is aware of (i) any significant deficiencies or material weaknesses in the design or operation of its internal controls over financial reporting (as defined in Rule 13a-15(f) and 15d-15(f) under the Exchange Act) that are likely to adversely affect the Partnership’s ability to record, process, summarize and report financial data; or (ii) any fraud, whether or not material, that involves management or other employees who have a role in the Partnership’s internal controls over financial reporting.

     (vv)  No Changes in Internal Controls . Since the date of the most recent evaluation of the disclosure controls and procedures described in Section 1(tt) hereof, there have been no significant changes in the Partnership’s internal controls that materially affected or are reasonably likely to materially affect the Partnership’s internal controls over financial reporting.

     (ww)  Sarbanes-Oxley Act . The principal executive officer and principal financial officer of the General Partner have made all certifications required by the Sarbanes-Oxley Act of 2002 (the “ Sarbanes-Oxley Act ”) and any related rules and regulations promulgated by the Commission, and the statements contained in any such certification are complete and correct. The Partnership and the General Partner are otherwise in compliance in all material respects with all applicable provisions of the Sarbanes-Oxley Act that are effective.

     (xx)  Rating of Notes. In accordance with Rule 2720(c)(3)(C) of the Conduct Rules of the National Association of Securities Dealers, Inc., the Notes have been rated in an investment grade category by Moody’s Investors Service, Fitch Ratings and Standard & Poor’s Ratings Services.

Any certificate signed by any officer of any Enterprise Party and delivered to the Representatives or counsel for the Underwriters pursuant to this Agreement shall be deemed a representation and warranty by the Enterprise Parties signatory thereto, as to the matters covered thereby, to each Underwriter.

     2.  Purchase and Sale of the Notes . On the basis of the representations and warranties contained in, and subject to the terms and conditions of, this Agreement, the Operating LLC agrees to issue and sell the Notes to the several Underwriters and each of the Underwriters, severally and not jointly, agrees to purchase from the Operating LLC (i) the

principal amount of the Notes due 2013 set forth opposite that Underwriter’s name in Schedule I hereto at a price equal to 99.306% of the principal amount thereof and (ii) the principal amount of the Notes due 2019 set forth opposite that Underwriter’s name in Schedule I hereto at a price equal to 99.216% of the principal amount thereof, in each case, plus accrued interest, if any, from the Delivery Date. The Operating LLC shall not be obligated to deliver any of the Notes except upon payment for all the Notes to be purchased as provided herein.

     The Operating LLC understands that the Underwriters intend to make a public offering of the Notes as soon after the effectiveness of this Agreement as in the judgment of the Representatives is advisable, and initially to offer the Notes on the terms and conditions set forth in the Pricing Disclosure Package and the Prospectus.

     3.  Offering of Securities by the Underwriters . It is understood that the Underwriters propose to offer the Securities for sale to the public as set forth in the Prospectus.

     4.  Delivery of and Payment for the Notes . Delivery of and payment for the Notes shall be made at the office of Andrews Kurth LLP, Houston, Texas, at 10:00 A.M., New York City time, on April 3, 2008 or such other date and time and place as shall be determined by agreement between the Underwriters and the Partnership and the Operating LLC (such date and time of delivery and payment for the Notes being herein called the “ Delivery Date ”). Payment for the Notes shall be made by wire transfer in immediately available funds to the account(s) specified by the Partnership and the Operating LLC to the Representatives against delivery to the nominee of The Depository Trust Company, for the account of the Underwriters, of one or more global notes representing the Securities (collectively, the “ Global Note ”), with any transfer taxes payable in connection with the sale of the Notes duly paid by the Operating LLC. The Global Note will be made available for inspection by the Representatives not later than 1:00 p.m., New York City time, on the business day prior to the Delivery Date.

     5.  Further Agreements of the Parties. Each of the Enterprise Parties covenants and agrees with the Underwriters:

     (a)  Preparation of Prospectus and Registration Statement . (i) To prepare the Prospectus in a form approved by the Underwriters and to file such Prospectus pursuant to Rule 424(b) under the Securities Act not later than Commission’s close of business on the second business day following the execution and delivery of this Agreement or, if applicable, such earlier time as may be required by Rule 430A(a)(3) under the Securities Act; (ii) to make no further amendment or any supplement to the Registration Statement or to the Prospectus except as permitted herein; (iii) to advise the Underwriters, promptly after it receives notice thereof, of the time when any amendment to the Registration Statement has been filed or becomes effective or any supplement to the Prospectus or any amended Prospectus has been filed and to furnish the Underwriters with copies thereof; (iv) to advise the Underwriters promptly after it receives notice thereof of the issuance by the Commission of any stop order or of any order preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus, of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding for any such purpose or of any request by the Commission for the amending or supplementing of the Registration Statement, the Prospectus or any Issuer Free Writing Prospectus or for additional information; and (v) in the event of the issuance of any stop

order or of any order preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus or suspending any such qualification, to use promptly its best efforts to obtain its withdrawal.

     (b)  Final Term Sheet and Issuer Free Writing Prospectuses. (i) To prepare a final term sheet, containing solely a description of final terms of the Securities and the offering thereof, in the form approve