Anadarko Announces $5 Billion Public Offering of Senior Notes.

HOUSTON -- Anadarko Petroleum Corporation (NYSE:APC) today announced it intends to commence a public offering of $5 billion of new issue senior notes. The offering is expected to include senior floating rate notes due 2009, senior fixed rate notes due 2016 and senior fixed rate notes due 2036. Anadarko intends to use the net proceeds from the offering to repay borrowings under its 364-day term loan agreement, which were used to finance its acquisitions of Kerr-McGee Corporation and Western Gas Resources, Inc.

The offering will be made under a shelf registration statement that became effective when filed by Anadarko earlier today.

Credit Suisse, UBS Investment Bank, Citigroup and Goldman, Sachs & Co. will act as joint book-running managers for the offering. The offering is being made only by means of a prospectus and related prospectus supplement, copies of which may be obtained from Credit Suisse, One Madison Avenue, Level 1B, New York, NY 10010, 212-325-2580; UBS Securities LLC, Attention: Fixed Income Syndicate, 677 Washington Blvd, Stamford, CT 06901, 888-722-9555 ext. 1088; Citigroup Global Markets Inc. at Brooklyn Army Terminal, 140 58th Street, 8th floor, Brooklyn, N.Y. 11220, phone: [phone], fax: [phone]; or Goldman, Sachs & Co., Attn: Prospectus Dept., 85 Broad Street, New York, NY 10004, Fax: [phone] or email at [e-mail]. An electronic copy of the prospectus and prospectus supplement is available from the Securities and Exchange Commission's website at www.sec.gov.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any state.

Anadarko Petroleum Corporation's mission is to deliver a competitive and sustainable rate of return to shareholders by exploring for, acquiring and developing oil and natural gas resources vital to the world's health and welfare. As of year-end 2005, the company had 2.45 billion barrels-equivalent of proved reserves, making it one of the world's largest independent exploration and production companies. In August 2006, Anadarko acquired Kerr-McGee Corporation and Western Gas Resources, Inc. in separate transactions.

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 Exchange Act of 1934. Anadarko believes that its expectations are based on reasonable assumptions. No assurance, however, can be given that such expectations will prove to have been correct. A number of factors could cause actual results to differ materially from the projections, anticipated results or other expectations expressed in this news release. See "Risk Factors" in the company's 2005 Annual Report on Form 10-K and other public filings, press releases and discussions with company management. Anadarko undertakes no obligation to publicly update or revise any forward-looking statements.