Mariner Sells Its Interest in Devils Tower

Mariner Energy, Inc. announced the sale of its remaining 20 percent working interest in the "Devils Tower" development project in the deepwater Gulf of Mexico to Dominion Exploration & Production, Inc., and Pioneer Natural Resources Company. Devils Tower is located in Mississippi Canyon Block 773, approximately 140 miles southeast of New Orleans. The sale, for an undisclosed amount of cash, was effective March 1, 2001, and increases Dominion Exploration & Production, Inc.'s working interest in the project from 60 percent to 75 percent and that of Pioneer Natural Resources Company from 20 percent to 25 percent.

Robert E. Henderson, President and Chief Executive Officer of Mariner, stated, "The sale of our remaining interest in Devils Tower is consistent with our strategy of actively managing our exploration and development portfolio to optimally allocate our capital resources. As stated previously, Mariner's 2001 capital budget, which is the largest in the history of the company, will be funded with cash from a variety of sources, including property conveyances when appropriate. The Devils Tower sale is consistent with this financing strategy and also gives us additional flexibility to pursue other opportunities in our deepwater Gulf niche."