Mariner Energy’s $850 Million Borrowing Base Affirmed

HOUSTON, March 26 /PRNewswire-FirstCall/ — Mariner Energy, Inc. (NYSE: ME) today announced that the borrowing base for its $1.0 billion secured revolving credit facility has been reaffirmed by its bank group at $850 million, its existing level since June 2008. The credit facility is provided by a syndicate of 17 banks led by Union Bank of California, N.A., and BNP Paribas. As of March 26, 2009, Mariner had approximately $220 million available under the credit facility. The facility’s borrowing base is redetermined semi-annually. In connection with the affirmation, Mariner agreed to a 1.0% increase to interest on outstanding borrowings and an increase to 0.5% for the commitment fee on unused capacity under the credit facility. Also, 100% lender approval will be required for a borrowing base in excess of $800 million at the next redetermination expected in August 2009.

“We appreciate the support from our banks in these uncertain times. In our view this reflects our strong performance in 2008 and our conservative business model,” said Scott Josey, Chairman, Chief Executive Officer and President of Mariner Energy.

About Mariner Energy, Inc.

Mariner Energy is an independent oil and gas exploration, development, and production company headquartered in Houston, Texas, with principal operations in the Permian Basin and the Gulf of Mexico. For more information about Mariner, visit the company’s website at www.mariner-energy.com.

This press release includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. All statements, other than statements of historical facts, that address activities that Mariner assumes, plans, expects, believes, projects, estimates or anticipates (and other similar expressions) will, should or may occur in the future are forward-looking statements. Our forward-looking statements generally are accompanied by words such as “may”, “will”, “estimate”, “project”, “predict”, “believe”, “expect”, “anticipate”, “potential”, “plan”, “goal”, or other words that convey the uncertainty of future events or outcomes. Forward-looking statements provided in this press release are based on Mariner’s current belief based on currently available information as to the outcome and timing of future events and assumptions that Mariner believes are reasonable. Mariner does not undertake to update its guidance, estimates or other forward-looking statements as conditions change or as additional information becomes available. Mariner cautions that its forward-looking statements are subject to all of the risks and uncertainties normally incident to the exploration for and development, production and sale of oil and natural gas. These risks include, but are not limited to, price volatility or inflation, environmental risks, drilling and other operating risks, regulatory changes, the uncertainty inherent in estimating future oil and gas production or reserves, and other risks described in the Annual Report on Form 10-K for the fiscal year ended December 31, 2008, as amended, and other documents filed by Mariner with the SEC. Any of these factors could cause Mariner’s actual results and plans of Mariner to differ materially from those in the forward-looking statements. Investors are urged to read the Annual Report on Form 10-K for the year ended December 31, 2008, as amended, and other documents filed by Mariner with the SEC. This press release does not constitute an offer to sell or a solicitation of an offer to buy any securities of Mariner.

SOURCE Mariner Energy, Inc.