Exhibit 3.B
























THIRD AMENDMENT
  TO
  GENERAL PARTNERSHIP AGREEMENT
  OF
  SOUTHERN NATURAL GAS COMPANY
          June 30, 2010














THIRD AMENDMENT
   TO
   GENERAL PARTNERSHIP AGREEMENT
   OF
   SOUTHERN NATURAL GAS COMPANY
  This THIRD AMENDMENT to GENERAL PARTNERSHIP AGREEMENT OF SOUTHERN NATURAL GAS COMPANY (the “Amendment”), is made and entered into as of this 30th day of June, 2010, by El Paso SNG Holding Company, L.L.C., a Delaware limited liability company (“EP SNG”), and EPPP SNG GP Holdings, L.L.C., a Delaware limited liability company (“EPPP SNG”), each as a general partner of the Partnership (collectively, “the Partners”).
   WITNESSETH:
  WHEREAS, Southern Natural Gas Company (“SNGC”), a Delaware corporation, owned and operated an interstate natural gas pipeline system and, through its subsidiaries, conducted other businesses; and
  WHEREAS, in accordance with Section 266 of the Delaware General Corporation Law (“DGCL”) and Section 15-901 of the Delaware Revised Uniform Partnership Act (“DRUPA”), SNGC was converted (the “Conversion”) into a Delaware general partnership (the “Partnership”), with the Partnership’s existence deemed in accordance with DRUPA Section 15 901(d) to have commenced on the date that SNGC commenced its existence as a Delaware corporation; and
  WHEREAS, pursuant to the General Partnership Agreement of Southern Natural Gas Company (the “Agreement”) and the Conversion, the stockholders of SNGC, EP SNG and EPPP SNG, became general partners of the Partnership, all of the issued and outstanding shares of capital stock in SNGC were converted into Partnership Interests in the Partnership, and the stockholders of SNGC became the owners of all of the Partnership Interests in the Partnership, each holding the Percentage Interest set forth opposite its name on Annex I to the Agreement; and
  WHEREAS, pursuant to the Contribution and Exchange Agreement dated September 17, 2008, the Agreement was amended on September 30, 2008 to reflect the contribution, transfer and conveyance to EPPP SNG of a 15% Percentage Interest in the Partnership such that EPPP SNG owned a 25% Partnership Interest and EP SNG owned a 75% Partnership Interest; and
  WHEREAS, pursuant to the Contribution Agreement dated June 17, 2010, and for good and valuable consideration, EP SNG agreed to contribute, transfer and convey to EPPP SNG an additional 16% Partnership Interest in the Partnership with a 90-day option to purchase an additional 4% Partnership Interest in the Partnership; and
      
 WHEREAS, on June 23, 2010, the Agreement was amended to reflect the contribution, transfer and conveyance to EPPP SNG of the additional 16% Percentage Interest in the Partnership such that EPPP SNG owns a 41% Partnership Interest and EP SNG owns a 59% Partnership Interest; and
  WHEREAS, on June 28, 2010, the Board of Directors of El Paso Pipeline GP Company, L.L.C. elected to exercise its option to acquire the additional 4% Partnership Interest in the Partnership; and
  WHEREAS, in accordance with Section 3.4 of the Agreement, the Partners and the Management Committee of SNGC have expressly approved and consented (and do hereby expressly approve and consent) to the admission of El Paso Pipeline Partners, L.P., a Delaware limited partnership, or its designee as a partner of SNGC owning a 45% Partnership Interest and having all of the rights, privileges and obligations relating thereto, including the right to vote on Partnership matters.
  NOW THEREFORE, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Partners hereby agree:
  1.           Annex I to the Agreement shall be deleted in its entirety and shall be replaced with the attached Annex I.
  2.           In accordance with Section 3.4 of the Agreement, the Partners and the Management Committee of SNGC have expressly approved and consented (and do hereby expressly approve and consent) to the admission of El Paso Pipeline Partners, L.P., a Delaware limited partnership, or its designee as a partner of SNGC owning a 45% Partnership Interest and having all of the rights, privileges and obligations relating thereto, including the right to vote on Partnership matters.


















-2-













IN WITNESS WHEREOF, the Partners have executed this Amendment as of the date first set forth above.







PARTNERS:EL PASO SNG HOLDING COMPANY, L.L.C.By:
/s/ James C. YardleyName:
James C. YardleyTitle:
President
 EPPP SNG GP HOLDINGS, L.L.C.By:
/s/ Rosa P. JacksonName:
Rosa P. JacksonTitle:
Vice President and Controller





[Signature page to Third Amendment to Partnership Agreement of Southern Natural Gas Company]
























-3-














ANNEX I







Partner Identity

and Address

Percentage

Interest

Number of Representatives and Alternative Representatives

Identity of Representatives

Identity of Alternate Representatives

ParentEl Paso SNG Holding

Company, L.L.C.

El Paso Building

1001 Louisiana

Houston, Texas 77002

Attention: ______

55%

3 Representatives

and up to 3 Alternates

Norman G. Holmes

Daniel B. Martin

Michael J. Varagona

William G. Cope

________________

________________

El Paso CorporationEPPP SNG GP

Holdings, L.L.C.

El Paso Building

1001 Louisiana

Houston, Texas 77002

Attention: ______

45%

1 Representative

1 Alternate

James C. Yardley

________________

El Paso PipelinePartners, L.P.