Anadarko Announces the Full Tender Offer Consideration for Its Maximum Debt Tender Offer.

HOUSTON -- Anadarko Petroleum Corp. (NYSE: APC) today announced the reference yield and the full tender offer consideration for its previously announced Maximum Tender Offer. The reference yield was determined at 2:00 p.m. EDT today. The full tender offer consideration for each security is based on the reference yield plus a fixed spread as set forth in the table below. All payments for securities purchased in the offers will include accrued and unpaid interest on the principal amount tendered up to, but not including, the Settlement Date, which is currently expected to be Thursday, Oct. 7, 2004.

Full Tender
                                                         Offer
                            Reference           Fixed    Consideration
                            U.S.                Spread   per $1000
                 Title of   Security  Reference (basis   principal
Issuer           Security   Treasury  Yield     points)  amount
-------------------------- --------- --------- -------- --------------
Offer for Notes Listed Below:  Maximum Tender Offer
Anadarko Holding 7.300%     3.125%
 Company         Notes      U.S.
                 due        Treasury
                 April 15   Note due
                 2009       April 15,
                            2009      3.365%    57       $1,138.15
Anadarko         6.125%     4.250%
                 Notes      U.S.
                 due        Treasury
                 March 15,  Note due
                 2012       Aug. 15,
                            2014      4.201%    35       $1,098.35
Anadarko         5.000%     4.250%
                 Notes      U.S.
                 due        Treasury
                 Oct. 1,    Note due
                 2012       Aug. 15,
                            2014      4.201%    39       $1,027.07

The Maximum Tender Offer will expire at 5:00 p.m. EDT on Wednesday, Oct. 6, 2004, unless extended or earlier terminated. Holders of securities subject to the Maximum Tender Offer who tendered their securities after 5:00 p.m., EDT, on Wednesday, Sept. 20, 2004 (the Early Tender Date) and do not withdraw their securities before 5:00 p.m., EDT, on the expiration date for the Maximum Tender Offer, will receive the Full Tender Offer Consideration minus $15.00 per $1,000 principal amount of securities tendered by such Holders that are accepted for purchase.

The terms and conditions of the Maximum Tender Offer, including the conditions of Anadarko's obligation to accept the securities tendered and to pay the Full Tender Offer Consideration plus accrued and unpaid interest, are set forth in the Offer to Purchase dated Sept. 9, 2004 and the related Letter of Transmittal. Each tender offer is made with respect to one series of Notes or Debentures and is independent of the other tender offers. Each tender offer, however, is conditioned upon satisfaction of certain conditions described in the Offer to Purchase.

Anadarko has retained ABN AMRO Incorporated and J. P. Morgan Securities Inc. to serve as joint dealer managers, and Global Bondholder Services Corporation to serve as the depositary agent and information agent for the tender offer. Requests for documents may be directed to Global Bondholder Services Corporation by telephone at 866-470-4300 or 212-430-3774 or in writing at 65 Broadway - Suite 74, New York, NY, 10006. Questions regarding the tender offer may be directed to either ABN AMRO at 866-409-7643 or 212-409-6255, or J. P. Morgan at 866-834-4666.

This press release is not a tender offer to purchase or a solicitation of acceptance of the tender offer, which may be made only pursuant to the terms of the Offer to Purchase.

Anadarko Petroleum Corporation's mission is to deliver a competitive and sustainable rate of return to shareholders by developing, acquiring and exploring for oil and gas resources vital to the world's health and welfare. As of year-end 2003, Anadarko had 2.5 billion barrels of oil equivalent of reserves, making it one of the world's largest independent exploration and production companies. Anadarko's operational focus extends from the deepwater Gulf of Mexico, up through Texas, Louisiana, the Mid-Continent, western U.S. and Canadian Rockies and onto the North Slope of Alaska. Anadarko also has significant production in Algeria, Venezuela and Qatar. For more information about how Anadarko is bringing excellence to the surface, please visit: http://www.anadarko.com.

This news release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities and Exchange Act of 1934. Anadarko believes that its expectations are based on reasonable assumptions. No assurance, however, can be given that its goals will be achieved. A number of factors could cause actual results to differ materially from the projections, anticipated results or other expectations expressed in this release. While Anadarko makes these forward-looking statements in good faith, neither Anadarko nor its management can guarantee that the anticipated future results will be achieved. See Regulatory Matters and Additional Factors Affecting Business in the Management's Discussion and Analysis included in the Company's 2003 Annual Report on Form 10-K.