COMMON UNIT PURCHASE AGREEMENT

This COMMON UNIT PURCHASE AGREEMENT, dated as of July 25, 2008 (this “ Agreement ”), is by and between REGENCY ENERGY PARTNERS LP, a Delaware limited partnership (“ Regency ”), and Neuberger Berman, LLC (“ Neuberger ”), acting in its capacity as investment advisor for certain clients on behalf of those clients for whom Neuberger is purchasing the Common Units (as defined below) (the “ Purchaser ”).

WHEREAS, Regency has filed with the Commission (as defined below), pursuant to the Securities Act (as defined below) and the rules and regulations adopted by the Commission thereunder, the Registration Statement (as defined below) relating to the offer and sale from time to time of up to $691,322,449 aggregate initial offering price of common units representing limited partner interests in Regency (“ Common Units ”) and certain other Regency securities, and such Registration Statement has become effective; and

WHEREAS, Regency desires to sell to the Purchaser, and the Purchaser desires to purchase from Regency, certain of those Common Units, in accordance with the provisions of this Agreement.

NOW THEREFORE, in consideration of the mutual covenants and agreements set forth herein and for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows:

Section 1.01       Definitions .  As used in this Agreement, and unless the context requires a different meaning, the following terms have the meanings indicated:

“ Affiliate ” means, with respect to a specified Person, any other Person, directly or indirectly controlling, controlled by or under direct or indirect common control with such specified Person.  For purposes of this definition, “control” (including, with correlative meanings, “controlling,” “controlled by,” and “under common control with”) means the power to direct or cause the direction of the management and policies of such Person, directly or indirectly, whether through the ownership of voting securities, by contract or otherwise.

“ Basic Documents ” means, collectively, this Agreement, the Partnership Agreement and any and all other agreements or instruments executed and delivered by the Parties to evidence the execution, delivery and performance of this Agreement, and any amendments, supplements, continuations or modifications thereto.

“ Business Day ” means any day other than a Saturday, Sunday, any federal legal holiday or day on which banking institutions in the State of New York or State of Texas are authorized or required by law or other governmental action to close.

“ Class D Units ” means the Class D units representing limited partner interests in Regency and any Common Units into which such Class D Units convert.

“ Closing ” shall have the meaning specified in Section 2.03 .

“ Closing Date ” shall have the meaning specified in Section 2.03 .

“ Commission ” means the United States Securities and Exchange Commission.

“ Common Units ” has the meaning set forth in the recitals.

“ Delaware LLC Act ” shall have the meaning specified in Section 3.02 .

“ Delaware LP Act ” shall have the meaning specified in Section 3.02 .

“ Effective Date ” shall have the meaning specified in Section 3.03 .

“ Effective Time ” shall have the meaning specified in Section 3.03 .

“ Exchange Act ” means the Securities Exchange Act of 1934, as amended from time to time, and the rules and regulations of the Commission promulgated thereunder.

“ GAAP ” means generally accepted accounting principles in the United States of America in effect from time to time.

“ General Partner ” means Regency GP LP, a Delaware limited partnership, and includes Regency GP LLC, a Delaware limited liability company and the general partner of Regency GP LP.

“ Governmental Authority ” means, with respect to a particular Person, any country, state, county, city and political subdivision in which such Person or such Person’s Property is located or which exercises valid jurisdiction over any such Person or such Person’s Property, and any court, agency, department, commission, board, bureau or instrumentality of any of them and any monetary authority which exercises valid jurisdiction over any such Person or such Person’s Property.  Unless otherwise specified, all references to Governmental Authority herein with respect to Regency means a Governmental Authority having jurisdiction over Regency, its Subsidiaries or any of their respective Properties.

“ Indemnified Party ” shall have the meaning specified in Section 5.03 .

“ Indemnifying Party ” shall have the meaning specified in Section 5.03 .

“ Law ” means any federal, state, local or foreign order, writ, injunction, judgment, settlement, award, decree, statute, law, rule or regulation.

“ Lien ” means any mortgage, claim, encumbrance, pledge, lien (statutory or otherwise), security agreement, conditional sale or trust receipt or a lease, consignment or bailment, preference or priority or other encumbrance upon or with respect to any property of any kind.

“ LTIP ” shall have the meaning specified in Section 3.02(b) .

“ NASDAQ ” means the NASDAQ Global Select Market.

“ Neuberger ” means Neuberger Berman, LLC, acting as investment advisor for certain clients on behalf of those clients for whom Neuberger is purchasing the Common Units.

“ Partnership Agreement ” means the Fourth Amended and Restated Agreement of Limited Partnership of Regency, dated February 15, 2006, as amended from time to time.

“ Partnership Securities ” means any class or series of equity interest in Regency (but excluding any options, rights, warrants and appreciation rights relating to an equity interest in Regency), including without limitation Common Units, Subordinated Units, Class D Units and the Incentive Distribution Rights (as defined in the Partnership Agreement).

“ Person ” means any individual, corporation, company, voluntary association, partnership, joint venture, trust, limited liability company, unincorporated organization, government or any agency, instrumentality or political subdivision thereof, or any other form of entity.

“ Property ” means any interest in any kind of property or asset, whether real, personal or mixed, or tangible or intangible.

“ Prospectus ” shall have the meaning specified in Section 3.03 .

“ Purchase Price ” means the $23,590,000 paid by the Purchaser for the Purchased Units; provided that if the Closing occurs after the record date of the distribution to Regency unitholders with respect to the quarter ended June 30, 2008, the Purchase Price will be reduced by an amount per Purchased Unit equal to such distribution.

“ Purchased Units ” means the 1,000,000 common units purchased by the Purchaser.

“ Purchaser Related Parties ” shall have the meaning specified in Section 5.01 .

“ Purchaser ” has the meaning set forth in the introductory paragraph of this Agreement.

“ Regency ” has the meaning set forth in the introductory paragraph.

“ Regency Credit Facility ” means the Fourth Amended and Restated Credit Agreement, dated as of August 15, 2006, as amended as of the date hereof and from time to time, by and among Regency and the lenders named therein, as amended as of the date hereof.

“ Regency Financial Statements ” shall have the meaning specified in Section 3.04 .

“ Regency Material Adverse Effect ” means any material and adverse effect on (a) the assets, liabilities, financial condition, business, operations, affairs or prospects of Regency and its Subsidiaries taken as a whole; (b) the ability of Regency and its Subsidiaries taken as a whole to carry on their business as such business is conducted as of the date hereof or to meet their obligations under the Basic Documents on a timely basis; or (c) the ability of Regency to consummate the transactions under any Basic Document; provided , however , that a Regency Material Adverse Effect shall not include any material and adverse effect on the foregoing to the extent such material and adverse effect results from, arises out of, or relates to (x) a general deterioration in the economy or changes in the general state of the industries in which the

“ Regency Parties ” means Regency, the General Partner and all of Regency’s Subsidiaries.

“ Regency Related Parties ” shall have the meaning specified in Section 5.02 .

“ Regency SEC Documents ” shall have the meaning specified in Section 3.04 .

“ Registration Statement ” shall have the meaning specified in Section 3.03 .

“ Representatives ” of any Person means the officers, directors, managers, employees, agents, counsel, accountants, investment bankers and other representatives of such Person.

“ Rules and Regulations ” shall have the meaning specified in Section 3.03 .

“ Securities Act ” means the Securities Act of 1933, as amended from time to time, and the rules and regulations of the Commission promulgated thereunder.

“ Subsidiary ” means, as to any Person, any corporation or other entity of which: (i) such Person or a Subsidiary of such Person is a general partner or manager; (ii) at least a majority of the outstanding equity interest having by the terms thereof ordinary voting power to elect a majority of the board of directors or similar governing body of such corporation or other entity (irrespective of whether or not at the time any equity interest of any other class or classes of such corporation or other entity shall have or might have voting power by reason of the happening of any contingency) is at the time directly or indirectly owned or controlled by such Person or one or more of its Subsidiaries; or (iii) any corporation or other entity as to which such Person consolidates for accounting purposes.

“ Transfer ” shall have the meaning specified in Section 4.06 .

Section 1.02                                  Accounting Procedures and Interpretation .  Unless otherwise specified herein, all accounting terms used herein shall be interpreted, all determinations with respect to accounting matters hereunder shall be made, and all Regency Financial Statements and certificates and reports as to financial matters required to be furnished to the Purchaser hereunder shall be prepared, in accordance with GAAP applied on a consistent basis during the periods involved (except as may be indicated in the notes thereto or, in the case of unaudited statements, as permitted by Form 10-Q promulgated by the Commission) and in compliance as to form in all material respects with applicable accounting requirements and with the published rules and regulations of the Commission with respect thereto.

Section 2.01                                  Sale and Purchase .  Subject to the terms and conditions hereof, Regency hereby agrees to issue and sell to the Purchaser, free and clear of any and all Liens, and the Purchaser hereby agrees to purchase from Regency, the Purchased Units, and the Purchaser agrees to pay Regency the Purchase Price.

Section 2.02                                  Closing.   Subject to the terms and conditions hereof, the consummation of the purchase and sale of the Purchased Units hereunder (the “Closing”) shall take place at 9:00 a.m., Central Daylight Time, on August 1, 2008 at the offices of Vinson & Elkins L.L.P., First City Tower, 1001 Fannin Street, Houston, Texas 77002, or at such other time and date not later than five (5) full Business Days thereafter as Regency and the Purchaser may agree (the “Closing Date”).  The parties agree that the Closing may occur via delivery of facsimiles of this Agreement and cross-receipts; provided, that originals of such documents are sent via overnight delivery to be received by the other party (or designee of such other party) on the first business day immediately following the Closing Date.

Section 2.03                                  Conditions to Closing.

(a)            Mutual Conditions .  The respective obligations of each party to consummate the purchase and issuance and sale of the Purchased Units shall be subject to the satisfaction on or prior to the Closing Date of each of the following conditions (any or all of which may be waived by a particular party on behalf of itself in writing, in whole or in part, to the extent permitted by applicable Law):

(i)                 no statute, rule, order, decree or regulation shall have been enacted or promulgated, and no action shall have been taken, by any Governmental Authority which temporarily, preliminarily or permanently restrains, precludes, enjoins or otherwise prohibits the consummation of the transactions contemplated hereby or makes the transactions contemplated hereby illegal; and

(ii)                 there shall not be pending any suit, action or proceeding by any Governmental Authority seeking to restrain, preclude, enjoin or prohibit the transactions contemplated by this Agreement.

(b) The Purchaser’s Conditions .  The respective obligation of the Purchaser to consummate the purchase of the Purchased Units shall be subject to the satisfaction on or prior to the Closing Date of each of the following conditions (any or all of which may be waived by the Purchaser in writing, in whole or in part with respect to its Purchased Units, to the extent permitted by applicable Law):

(i)                 since the date of this Agreement, no Regency Material Adverse Effect shall have occurred and be continuing;

(ii)                 no notice of delisting shall have been received by Regency;

the Closing Date as if made on and as of the Closing Date (except that representations made as of a specific date shall be required to be true and correct as of such date only); and

(iv)                 Regency shall have delivered, or caused to be delivered, to the Purchaser at the Closing, Regency’s closing deliveries described in Section 2.04 .

(c)       Regency’s Conditions .  The obligation of Regency to consummate the sale of the Purchased Units to the Purchaser shall be subject to the satisfaction on or prior to the Closing Date of the following condition (which may be waived by Regency in writing, in whole or in part, to the extent permitted by applicable Law): the representations and warranties of the Purchaser contained in this Agreement shall be true and correct in all material respects at and as of the Closing Date as if made on and as of the Closing Date (except that representations made as of a specific date shall be required to be true and correct as of such date only).

Section 2.04       Regency Deliveries.   At the Closing, subject to the terms and conditions hereof, Regency will deliver, or cause to be delivered, to the Purchaser:

(a)           The Purchased Units by electronic delivery to The Depository Trust Company on Purchaser’s behalf, registered in such name(s) as Purchaser has designated;

(b)           Copies of (i) the Certificate of Limited Partnership of Regency, (ii) the Certificate of Limited Partnership of Regency GP LP and (iii) the Certificate of Formation of Regency GP LLC, each certified by the Secretary of State of the jurisdiction of its formation as of a recent date;

(c)           A certificate of the Secretary of State of the State of Delaware, dated a recent date, that Regency is in good standing;

(d)           A cross-receipt executed by Regency and delivered to the Purchaser certifying that it has received the Purchase Price as of the Closing Date;

(e)           An opinion addressed to the Purchaser from legal counsel to Regency , dated as of the Closing Date, in the form and substance attached hereto as Exhibit A ;

(f)           A copy of the final prospectus supplement relating to the Purchased Units and the offering thereof, including the accompanying base prospectus, substantially in the form that will be filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations after the date and time this Agreement is executed;

(g)           A certificate of the Secretary or Assistant Secretary of Regency GP, LLC, on behalf of Regency, certifying as to and attaching (1) the Partnership Agreement, (2) board resolutions authorizing the execution and delivery of the Basic Documents and the consummation of the transactions contemplated thereby, including the issuance of the Purchased Units and (3) its incumbent officers authorized to execute the Basic Documents, setting forth the name and title and bearing the signatures of such officers; and

(h)           A certificate, dated the Closing Date and signed by (x) the Chief Executive Officer and (y) the Chief Financial Officer of Regency GP, LLC, in their capacities as such, stating that:

(i)                 Regency has performed and complied with the covenants and agreements contained in this Agreement that are required to be performed and complied with by Regency on or prior to the Closing Date;

(ii)                 The representations and warranties of Regency contained in this Agreement that are qualified by materiality or Regency Material Adverse Effect were true and correct when made and as of the Closing Date and all other representations and warranties were true and correct in all material respects when made and are true and correct in all material respects as of the Closing Date, in each case as though made at and as of the Closing Date (except that representations made as of a specific date shall be required to be true and correct as of such date only).

Section 2.05       The Purchaser’s Deliveries.   At the Closing, subject to the terms and conditions hereof, the Purchaser will deliver, or cause to be delivered, to Regency:

(a)           Payment to Regency of the Purchase Price by wire transfer of immediately available funds to an account designated by Regency in writing at least two Business Days prior to the Closing Date; and

(b)           A cross-receipt executed by the Purchaser and delivered to Regency certifying that it has received its respective Purchased Units as of the Closing Date.

Regency represents and warrants to and covenants to the Purchaser as follows:

Section 3.01       Partnership Existence .  Regency (a) is a limited partnership duly formed, validly existing and in good standing under the laws of the State of Delaware; and (b) has all requisite power and authority, and has all governmental licenses, authorizations, consents and approvals necessary, to own, lease, use and operate its Properties and carry on its business as its business is now being conducted, except where the failure to obtain such licenses, authorizations, consents and approvals would not be reasonably likely to have a Regency Material Adverse Effect.  Each of Regency’s Subsidiaries has been duly incorporated or formed, as the case may be, and is validly existing and in good standing under the laws of the State or other jurisdiction of its incorporation or organization, as the case may be, and has all requisite power and authority, and has all governmental licenses, authorizations, consents and approvals necessary, to own, lease, use or operate its respective Properties and carry on its business as now being conducted, except where the failure to obtain such licenses, authorizations, consents and approvals would not be reasonably likely to have a Regency Material Adverse Effect.  None of Regency nor any of its Subsidiaries are in default in the performance, observance or fulfillment of any provision of, in the case of Regency, the Partnership Agreement or its Certificate of Limited Partnership or, in the case of any Subsidiary of Regency, its respective certificate of incorporation, certification of

formation, bylaws, limited liability company agreement or other similar organizational documents.  Each of Regency and its Subsidiaries is duly qualified or licensed and in good standing as a foreign limited partnership, limited liability company or corporation, as applicable, and is authorized to do business in each jurisdiction in which the ownership or leasing of its respective Properties or the character of its respective operations makes such qualification necessary, except where the failure to obtain such qualification, license, authorization or good standing would not be reasonably likely to have a Regency Material Adverse Effect.

Section 3.02       Capitalization and Valid Issuance of Purchased Units

(a)           As of the date of this Agreement, prior to the issuance and sale of the Purchased Units, as contemplated hereby, the issued and outstanding limited partner interests of Regency consist of 45,724,516 Common Units, 19,103,896 Subordinated Units, 7,276,506 Class D Units and the Incentive Distribution Rights (as defined in the Partnership Agreement).  The only issued and outstanding general partner interests of Regency are the interests of the General Partner described in the Partnership Agreement.  All outstanding Common Units, Subordinated Units, Class D Units and Incentive Distribution Rights and the limited partner interests represented thereby have been duly authorized and validly issued in accordance with the Partnership Agreement and are fully paid (to the extent required under the Partnership Agreement) and nonassessable (except as such nonassessability may be affected by matters described in Section 17-607 of the Delaware Revised Uniform Limited Partnership Act (the “ Delaware LP Act ”)).

(b)           Other than the Regency GP LLC Long-Term Incentive Plan (the “ LTIP ”), Regency has no equity compensation plans that contemplate the issuance of partnership interests of Regency (or securities convertible into or exchangeable for partnership interests of Regency).  No indebtedness having the right to vote (or convertible into or exchangeable for securities having the right to vote) on any matters on which Regency unitholders may vote are issued or outstanding.  Except as set forth in the first sentence of this Section 3.02(b) , as contemplated by this Agreement or as are provided in the Partnership Agreement, there are no outstanding or authorized (i) options, warrants, preemptive rights, subscriptions, calls, or other rights, convertible or exchangeable securities, agreements, claims or commitments of any character obligating Regency or any of its Subs