CIBC World Markets Annual Global Energy Conference March 19-21, 2002

Forward-looking statement 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 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.

Area of Operations Over 50 blocks in Gulf of Mexico 7 blocks in North Sea WC 152 WC 101

Company Overview  Founded in 1991  A “D & P” company – Development and Production – Offshore solution provider for exploration-oriented majors and independents  Win/win for ATP and seller

Company history ATP was founded in 1991 and completed an initial public offering in February ATP forms its first limited partnership to provide funding for operations 1991 The Company is incorporated on August 8th ATP forms a second partnership and commences development activities in the Gulf of Mexico ATP acquires the third-party interests from its two partnerships and enters into a new financing arrangement The Company completes its first sub-sea development ATP wins numerous awards for its outstanding technological achievements and growth record ATP acquires all properties of Statoil (US) on the outer- Continental Shelf of the Gulf of Mexico The Company completes its initial public offering in February and acquires its first properties in the UK North Sea ATP becomes one of the first independent development companies to utilize horizontal drilling in offshore operations ATP opens the U.K. office commencing operations in the Southern Gas Basin of the UK North Sea ATP awarded UKCS Blocks 42/25a and 43/21a by DTI as an Out of Round License

E&P Valuation Table Sorted by Enterprise Value to 2002 EBITDA

E&P Valuation Table by YTD Stock Price Performance

Events Affecting ATP in National Events Missed Production Target Liquidity Deficit

Garden Banks 409 (Ladybug) 5 Bcfe and concurrent revenues deferred from 2001 to 2002

Liquidity  Late Q2 of 2001, ATP withdrew, due to market conditions, a $150 million public debt offering. – Natural gas price falling reduced revenues – Service industry and rig costs rose during the same period – Working capital deficit: June 30, 2001 $45 million  ATP management and control – ATP as operator controls all 12 projects under development – ATP reduced development activity after June 30, 2001  Result – Working capital deficit : Q$45 million Q$33 million Q $9 million (1) 2002 Positive working capital (1) 1 Company estimates

2001 Benchmarks Production Reserves Reserve Replacement Debt Revenues EBITDA Cash Flow

2001 Benchmarks Production Reserves Reserve Replacement Debt Revenues EBITDA Cash Flow ATP Record Almost Doubled 527% Reduced 14% Grew by 5+% Over 62% for 6 straight years Grew by 10+%

Production Bcfe

Reserves Bcfe

Proved Reserves Per Share Mcfe per share

Reserve Replacement Average Reserve Replacement: % %

Debt Reduction

Historical operating performance Dollars in millions 1 Company estimates EBITDA to Revenue Margin 68% 72% 62% 65% 64+%

Cash Flow Dollars in millions 1 Company estimates 1

Operational Expertise of Senior Officers NameAge Background Leland E Tate 54 - President, ARCO North Africa Senior Vice President - Director General, ARCO Joint Ventures Operations - Director of Operations, ARCO British Ltd, North Sea - VP Engineering, ARCO International - Vice President, ARCO Gulf of Mexico Adrian Turner 47 - President, ARCO Middle East Managing Director - Managing Director, ARCO Asia Pacific ATP Oil & Gas (UK) Ltd. - Commercial Vice President, BP Amoco - Commercial Negotiator, ARCO UK and Conoco, North Sea G. Ross Frazer 46 - Operations and Engineering Manager, British-Borneo Exploration, Inc. Vice President - - Chairman, American Petroleum Institute Houston Chapter Advisory Board Engineering - Member, American Petroleum Institute Houston Chapter – Deep Water Operations Steering Committee Robert M. Shivers 44 - Commercial/Development Manager – Deepwater Gulf of Mexico, Texaco Vice President - - Asset and Project Team Manager – UK North Sea, Texaco Projects - Drilling Engineering Manager – Gulf of Mexico/North Sea, Texaco

Strong development track record Inception (1991) – December 31, 2001 PUD’s taken to production 28 PUD’s in development planning12 Extensive Subsea Expertise Subsea Wells Operated 10 Subsea Development Wells Planned 7 Industry Leader in Long Reach Subsea Tiebacks - Ladybug18 miles 100% of properties under development are operated, allowing control of the timing and amount of capital expenditure

2002 Production Guidance Bcfe 1Q Bcfe Recent Development South Marsh Island 189 Projected Start Date April 2002 Actual First ProductionMarch 18, 2002

ATP Upside Outer Continental Shelf Shallow Deepwater GOM North Sea

Strategy and property overview Company Strategy Acquire, develop and produce proved reserves WC 152 WC 101

Garden Banks 409 (Ladybug) WC 152 WC 101 Ladybug ATP Operated 1 million barrels produced after 135 days

North Sea - Southern Gas Basin

North Sea Southern Gas Basin ATP Acquisition Blocks Other Opportunities

Investment Considerations  Six straight years of increases in Production Reserves Revenues EBITDA Cash flow  ATP Upside North Sea Shallow Deepwater GOM Outer Continental Shelf

Investment Considerations  2001 per share amounts – Cash flow estimate per share$2.40+/- – Proved reserves per share11.6 Mcfe  Stock price March 15, 2002$3.45  Stock price to cash flow 1.43X  Stock price to proved reserves $0.30X

Recipient of numerous oil & gas industry and business awards Oil & Gas World 1999 Best Field Improvement Gulf of Mexico T. Paul Bulmahn Entrepreneur of Year 2000 Energy & Energy Services Ernst & Young Financial Times of London 2000 Finalist: Best Oil and Gas Company 2000 Inc./Cisco Growing with Technology Award Inc Consecutive Years Fastest Growing Energy Company Each Year

NASDAQ: ATPG ATP Oil & Gas Corporation 4600 Post Oak Place, Suite 200 Houston, TX