Pioneer Announces Executive Appointments

Pioneer Natural Resources announced that Timothy L. ("Tim") Dove has been named President and Chief Operating Officer and Richard P. ("Rich") Dealy has been named Executive Vice President and Chief Financial Officer. Both positions will report to Scott D. Sheffield, Pioneer's Chairman and CEO.

As President and COO, Mr. Dove will be responsible for all of Pioneer's oil and gas assets and operations, both domestic and international, and for the Company's engineering and oil and gas marketing activities. Mr. Dove was formerly Pioneer's Executive Vice President and CFO.

"As an integral part of our management team for many years, Tim has earned our respect as a strategic leader with a broad depth of knowledge," stated Mr. Sheffield. "I am confident that our asset teams will benefit from his leadership, and I look forward to continuing to work with Tim to increase Pioneer's value for our stakeholders and employees."

Mr. Dealy, currently Pioneer's Vice President and Chief Accounting Officer, will replace Mr. Dove as CFO, and Darin G. Holderness has agreed to join the Company as Vice President and Chief Accounting Officer. He will report to Mr. Dealy.

"Rich is a valued member of Pioneer's management team, and I'm certain that with his financial experience and leadership skills, he will continue to serve the Company well as CFO. We also welcome Darin to Pioneer to head up our accounting group, and are pleased to be gaining the benefit of his extensive industry experience," stated Mr. Sheffield.

Mr. Dove has been with Pioneer for the past 10 years serving in various vice president roles with responsibility for international activities and business development and has served as Executive Vice President and CFO since 2000. Prior to joining Pioneer, he was with Diamond Shamrock and its successor, Maxus Energy, serving in various capacities in international exploration and production, marketing, refining, and planning and development. Mr. Dove earned his Bachelor of Science degree in mechanical engineering from Massachusetts Institute of Technology in 1979 and received his M.B.A. from the University of Chicago in 1981.

Mr. Dealy joined Pioneer's accounting team in 1992 and was promoted to Vice President and Chief Accounting Officer in 1998 having served as Controller since 1995. He is a Certified Public Accountant, and prior to joining Pioneer, he was with KPMG Peat Marwick. Mr. Dealy graduated with honors from Eastern New Mexico University with a Bachelor of Business Administration degree in Accounting and Finance.

Mr. Holderness is also a Certified Public Accountant and joins Pioneer with 18 years of industry accounting experience, most recently as Vice President, Finance and Treasurer of Basic Energy Services, Inc. He joined a predecessor of Pure Resources, Inc. in 1998 as an officer and Assistant Controller and became Vice President and Controller in 2002. He began his professional career with KPMG Peat Marwick in 1986 after graduating from Boise State University with a Bachelor of Business Administration degree in Accounting.