press release

ATP Oil & Gas Corporation exceeds 2 million barrels of production for Garden Banks 409

The following news release was issued by ATP Oil & Gas Corporation

HOUSTON - July 22, 2002 - ATP Oil & Gas Corporation (NASDAQ: ATPG) announces that gross production at its Garden Banks Block 409 project, also known as "Ladybug", has exceeded 2 million barrels as of July 15, 2002, at an average over 7,000 barrels of oil per day. In addition, cumulative gross natural gas production has exceeded 2.1 billion cubic feet (Bcf). ATP's net cumulative production amounts to approximately one million barrels of oil at an average of over 3,100 barrels of oil per day and approximately 1 Bcf of natural gas at an average of about 2.8 million cubic feet of natural gas per day.

ATP, as the operator, commenced production in September 2001 from the Ladybug field located in approximately 1360 feet of water by connecting two subsea wells with two six-inch eighteen-mile flow lines to a platform in Garden Banks Block 189. ATP and Unocal Corp. (NYSE: UCL) each hold a 50% working interest.

Ladybug is a project for which the Minerals Management Service ("MMS") granted deepwater royalty relief. The deepwater royalty relief program is administered by the MMS and is designed to encourage the development of marginal fields, such as Ladybug, in deepwater.

About ATP Oil & Gas

ATP Oil & Gas is focused on development and production of natural gas in the Gulf of Mexico and the North Sea. The company trades publicly as ATPG on the NASDAQ National Market.

Certain statements included in this news release are "forward-looking statements" under the Private Securities Litigation Reform Act of 1995. ATP cautions that assumptions, expectations, projections, intentions or beliefs about future events may and often do vary from actual results and the differences can be material. Some of the key factors which could cause actual results to vary from those ATP expects include changes in natural gas and oil prices, the timing of planned capital expenditures and availability of acquisitions, uncertainties in estimating proved reserves and forecasting production results, operational factors affecting the commencement or maintenance of producing wells, the condition of the capital markets generally, and uncertainties regarding environmental regulations or litigation and other legal or regulatory developments affecting our business. More information about the risks and uncertainties relating to ATP's forward-looking statements are found in our SEC filings.

Updated: July 2002