Anadarko Declares Quarterly Dividends on Common and Preferred Stock; Approves Share Increase to Complete 2-for-1 Split.

HOUSTON -- The Board of Directors of Anadarko Petroleum Corporation (NYSE:APC) has declared quarterly cash dividends on two classes of the company's stock. Anadarko's shareholders also approved the share increase necessary to complete the previously announced 2-for-1 split of the company's common stock.

The stock split will be effected in the form of a stock dividend, which will be delivered on May 26, 2006. Each Anadarko shareholder will receive one additional share for every share of common stock held of record as of the close of business on May 12, 2006. Anadarko's common stock should begin trading on a post-split basis May 30, 2006.

A dividend of 9 cents per share was declared on the company's outstanding common stock, payable on June 28, 2006, to stockholders of record at the close of business on June 14, 2006. This dividend has been adjusted to reflect the completion of the 2-for-1 stock split.

A dividend of $13.65 per share (equivalent to $1.365 per Depositary Share) was declared on the company's 5.46% Series B Cumulative Preferred Stock, payable on June 30, 2006, to stockholders of record at the close of business on June 15, 2006.

ANADARKO PETROLEUM CORPORATION (NYSE:APC)

                                              5.46% Series B
                   Common Stock         Cumulative Preferred Stock

Record Date:       June 14, 2006        June 15, 2006
Payment Date:      June 28, 2006        June 30, 2006
Amount:            9 cents per share    $13.65 per share
                                        (Equivalent to $1.365 per
                                         Depositary Share)

The amount of future dividends for Anadarko common stock will depend on earnings, financial condition, capital requirements and other factors. The Board of Directors will determine dividends on a quarterly basis.

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. Anadarko's operational focus in North America extends from the deepwater Gulf of Mexico, up through the western U.S. and Canadian regions and onto the North Slope of Alaska. Anadarko's international activities are focused on its major positions in North Africa, the Middle East, Indonesia and exploration or production operations in several other countries. For more information about how Anadarko is bringing excellence to the surface, please visit: www.anadarko.com.