ATP Oil & Gas ATP Oil & Gas Corporation Raymond James Conference March 3-5, 2003 Hellvelyn January 2003

ATP Oil & Gas Company Overview  Founded1991  TickerATPG (NASDAQ)  Share Price$4.23 (2/25/2003)  Shares Outstanding20.3 million  Employees49

ATP Oil & Gas Company Profile  Development and production (D&P) company  Offshore solution provider for exploration oriented majors and independents  Repeatable strategy Gulf of Mexico (1993) U.K. Sector North Sea (2000) Dutch Sector North Sea (2003)  Rate-of-return focused

ATP Oil & Gas D&P the Keystone of Our Business For the Sellers Eliminates future capital expenditures Generates cash and/or overrides Frees capital for other core projects For ATP Eliminates exploration risk Reduces acquisition and development costs Shortens duration of risked capital Development and Production (D&P)

ATP Oil & Gas Area of Operations 50 blocks in Gulf of Mexico 8 blocks in North Sea

ATP Oil & Gas History of Outstanding Performance

ATP Oil & Gas History of Outstanding Performance

ATP Oil & Gas History of Outstanding Performance

ATP Oil & Gas 2002 Reserves Proved Reserves (12/31/02)231 Bcfe

ATP Oil & Gas 2002 Production Production for Bcfe  Guidance for Bcfe Production exceeded guidance despite over 1 Bcfe of curtailed production related to Hurricanes Isidore and Lili.

ATP Oil & Gas Gulf of Mexico ATP Oil & Gas Corporation

ATP Oil & Gas Gulf of Mexico Developments First Half 2003 Three major developments moving 19 Bcfe to either production or PDNP Developments:  WC 101  EI 71  WC 284

ATP Oil & Gas Gulf of Mexico Developments Second Half 2003 Two major developments moving 28 Bcfe to production. Developments:  SS 358  GB 142 (Matia) and GB 186 / 187 (Cabrito)

ATP Oil & Gas U.K. Sector - North Sea ATP Oil & Gas Corporation

ATP Oil & Gas Helvellyn  Tested 60 MMcfpd January 2003  2002 net proved reserves increased 26 %  ATP Operator 50% W.I.  Rotliegend/Carboniferous  Water depth 90’  One-well, sub-sea tieback  1,800’ Horizontal section Helvellyn

ATP Oil & Gas Helvellyn Field Development 1,800’ Horizontal Section

ATP Oil & Gas U.K. North Sea Developments Venture (2003 – 2004)  ATP Operator 50% W.I.  Conoco Phillips 50% W.I.  One-well, sub-sea tieback  Two prior wells drilled  First gas 2004  Rotliegend/Carboniferous The Tors (2004 – 2005)  ATP Operator 75% W.I.  Gaz de France 25% W.I.  Two-well, single platform  Three prior wells drilled  First gas 2005  Rotliegend/Carboniferous

ATP Oil & Gas Dutch Sector – North Sea ATP Oil & Gas Corporation

ATP Oil & Gas Dutch North Sea Development L-6 (2004)  ATP Operator 50% W.I.  EBN 50% W.I.  First gas 2004  Jurassic Sand

ATP Oil & Gas ATP Oil & Gas Financial Overview

ATP Oil & Gas 2002 Reserves

ATP Oil & Gas Prospects to Production Conversion of undeveloped to proven developed reserves in first quarter 2003, considerably increases the value of proven developed (PD) reserves.

ATP Oil & Gas 2002 Financial Overview  Cash $7.4 million  Bank & Subordinated Debt$86.4 million  3-Year F&D (1) $1.08 / Mcfe  1-Year F&D (1) $1.55 / Mcfe (1)F&D Costs = (Costs Incurred – Divestitures – Capitalized Interest & G&A)/(Change Proved Reserves + Production) Note Costs Incurred estimate is $35 million for 2002.

ATP Oil & Gas Debt Decreased Another $14 Million in 2002

ATP Oil & Gas 2003 CAPEX $60 million 2003 CAPEX Budget :  Funded completely from operating cash flow  74% increase over 2002 CAPEX  Will move in excess of 50 Bcfe of proven undeveloped (PUD) to proven developed (PD)

ATP Oil & Gas New 2003 Oil Hedges Appendix for complete hedging schedule

ATP Oil & Gas New 2004 Natural Gas Hedges Appendix for complete hedging schedule

ATP Oil & Gas Peer Group - Introduction

ATP Oil & Gas Finding and Development Costs

ATP Oil & Gas Reserve Replacement

ATP Oil & Gas Small-caps have similar production profiles Peer Group Comparison - Production

ATP Oil & Gas Peer Group Comparison - Cash Flow

ATP Oil & Gas Peer Group Comparison - Valuation Enterprise Value to EBITDA Multiple Conclusion: On an enterprise value and cash flow basis, ATP is undervalued.

ATP Oil & Gas Summary  Experienced operator in three core areas  Gulf of Mexico  U.K. Sector North Sea  Dutch Sector North Sea  2002 was a very strong year for the company  Robust inventory of development properties in Gulf of Mexico and North Sea  Upside potential in 2003 based on enterprise and cash flow valuations.

ATP Oil & Gas Forward Looking Statements This presentation contains projections and other forward looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of These projections and statements reflect the Company’s current view with respect to future events and financial performance. No assurances can be given, however, that these events will occur or that these projections will be achieved, and actual results could differ materially from those projected as a result of certain factors. A discussion of these factors is included in the Company documents filed with the Securities and Exchange Commission. This presentation does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy or an attempt to influence any voting of securities, by any person.

ATP Oil & Gas NASDAQ: ATPG ATP Oil & Gas Corporation 4600 Post Oak Place, Suite 200 Houston, TX ATP Oil & Gas (UK) Limited Victoria House, London Square, Cross Lanes Guildford, Surrey GU1 1UJ United Kingdom 44 (0) ATP Oil & Gas Corporation

ATP Oil & Gas ATP Oil & Gas Corporation Appendix (Chart Pack): A: Natural Gas Hedges B: Crude Hedges C: Reserve Replacement D: Enterprise Value / EBITDA (Peer Group)

ATP Oil & Gas Natural Gas Hedges

ATP Oil & Gas Oil Hedges

ATP Oil & Gas Reserve Replacement History Reserve Replacement 413% 187% 85% 527% 138% 0% 100% 200% 300% 400% 500% 600% 700% Reserve Replacement (98-02) :292%

ATP Oil & Gas Enterprise Valuation