press release

ATP Oil & Gas awarded deepwater royalty relief by MMS; marks record production for Garden Banks 409

HOUSTON, March 27 -- ATP Oil & Gas Corporation (Nasdaq: ATPG) was awarded deepwater royalty relief by the Minerals Management Service (MMS) for the Garden Banks Block 409 Field, known as "Ladybug," which delivered cumulative gross production of 1 million barrels in only 135 days at an average of 7,418 barrels of oil per day (Bopd) and 8 million cubic feet of natural gas per day (MMcfd).

The Minerals Management Service of the U.S. Department of the Interior grants federal royalty relief as incentive to independents to actively develop marginal properties in the Gulf of Mexico and address the nation's energy needs. Royalty relief adds an additional 467 Bopd and an additional .47 MMcfd net to ATP's interest. With royalty relief, the net production to ATP from Ladybug is approximately 3,600 Bopd and 3.6 MMcfd.

ATP is one of the most active operators utilizing subsea technology in the Gulf of Mexico. By connecting the two Ladybug subsea wells with two six-inch eighteen-mile flow lines, ATP commenced production in September 2001 from the Garden Banks Block 409 Field located in approximately 1360 feet of water. ATP and Unocal Corp. (NYSE: UCL) each hold a 50% working interest, with ATP as operator.

About ATP Oil & Gas

ATP Oil & Gas (www.atpog.com) is focused on acquisition, development and production of natural gas in the Gulf of Mexico and the North Sea. The company now trades publicly as ATPG on the NASDAQ National Market and was recently added to the Russell 2000(R).

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: March 2002