Antero Resources Corporation Announces Equity Financing.

Business Editors

DENVER--(BUSINESS WIRE)--Feb. 18, 2003

Veteran management team led by Paul Rady and Glen Warren

secures $260 million equity funding program and closes

initial property transaction.

Antero Resources Corporation announced today that the Denver-based company has secured a $260 million equity program led by Warburg Pincus LLC. Joining Warburg Pincus, a leading private equity investor in the energy sector, are Yorktown Energy Partners V, LP, Lehman Brothers Merchant Banking Group and the Antero Resources management team.

Paul M. Rady, Chairman and CEO of Antero Resources, and Glen C. Warren, Jr., President and CFO, formed Antero Resources in 2002 to acquire, exploit, explore for, develop and produce natural gas. The Company will focus predominantly within the Rocky Mountain and Mid-Continent regions of the United States, areas where management has extensive experience.

"We are pleased to launch a company with such strong investor support, including some of the most highly regarded and experienced private equity investors in this sector," said Rady. "Our business strategy is to acquire primarily non-conventional producing properties with development drilling upside as well as undrilled acreage in emerging plays. The Antero Resources management team has worked together for many years at prior companies and excels at finding and developing natural gas in the Rockies and Mid-Continent."

The equity program will be drawn upon to fund these activities, subject to approval by management and the investors. Immediately after the initial funding, the Company used a portion of the proceeds to complete the acquisition of a Mid-Continent property containing approximately 20 billion cubic feet (Bcf) of proved reserves and more than 3 million cubic feet (MMcf) per day of net production.

Previously, Rady was Chairman, President and CEO of Pennaco Energy, Inc. (AMEX:PN) and Warren was Pennaco's Executive Vice President and CFO. Rady and Warren led Pennaco as it rapidly grew from a small acreage holder in the Powder River Basin coal bed methane play in Wyoming to a successful public company with net production of over 50 MMcf per day. Less than three years after its inception, Pennaco was sold for $500 million in cash to Marathon Oil (NYSE:MRO) in February 2001. Rady and Warren are joined by all of the key members of the senior management team that helped build Pennaco as well as other industry senior managers. Prior to Pennaco, Rady was President and CEO of Barrett Resources Corporation (NYSE:BRR), another public company which was focused on natural gas production in the Rockies.

Peter R. Kagan, a Warburg Pincus Managing Director, said: "We are very impressed by what Paul Rady and his management team have accomplished in their previous ventures. We are confident this team can once again apply its talents to capture unexploited value in the Rockies and Mid-Continent regions and we are thrilled to be their partners in this effort." He added: "This investment is consistent with our practice in the energy sector of backing strong management to build meaningful companies."

Warburg Pincus has invested approximately $400 million in early stage exploration and production companies over the last 12 years including: Newfield Exploration, Lariat Petroleum, Spinnaker Exploration, Encore Acquisition Company, Carneros Energy, Bill Barrett Corporation, and Latigo Petroleum.

Lehman Brothers acted as the exclusive placement agent for Antero Resources Corporation in the private equity funding effort.

About Antero Resources

Antero Resources Corporation is an independent oil and gas company that was formed in 2002 with headquarters in Denver, Colorado. The Company's strategy is to acquire, exploit, explore for, develop and produce natural gas predominantly within the Rocky Mountain and Mid-Continent regions of the United States.

About Warburg Pincus

With nearly $10 billion under management and approximately $6 billion available for investment, Warburg Pincus has been a leading private equity investor since 1971. The firm has invested more than $15 billion in over 469 companies in 29 countries. Warburg Pincus has invested approximately $400 million in early stage exploration and production companies over the last 12 years including; Newfield Exploration (NYSE:NFX), Lariat Petroleum, Spinnaker Exploration (NYSE:SKE), Encore Acquisition Company (NYSE:EAC), Carneros Energy, Bill Barrett Corporation, and Latigo Petroleum. Warburg Pincus has also taken an active role in building businesses with energy companies involved in energy and power, oilfield and other services. Throughout its history in private equity, Warburg Pincus has invested at all stages of a company's life cycle, from founding start-ups and providing growth capital to leading restructurings, recapitalizations and buyouts. For more information, please visit www.warburgpincus.com.

About Yorktown Partners

Yorktown Energy Partners V, L.P. is the fifth energy dedicated private equity partnership managed by Yorktown Partners LLC. Beginning in 1983, Yorktown has made over 40 investments in a variety of energy companies that range from oil and gas production to pipeline construction to oil field services to energy-specific manufacturing. Yorktown currently has in excess of $1.5 billion under management.

About Lehman Brothers Merchant Banking Group

Lehman Brothers Merchant Banking Group is part of Lehman Brothers Holdings Inc. and is engaged in making private equity investments in a variety of industries, including energy.