Pioneer Takes Stake in Spraberry Field, Texas

Pioneer Natural Resources has entered into an agreement to acquire an interest in approximately 44,000 gross acres in the Spraberry field in West Texas for $90 million, before normal closing adjustments. Pioneer will operate the acquired properties with an average 85% working interest. The acquisition is expected to close during the fourth quarter of 2007 and is subject to customary closing conditions. Pioneer plans to use a portion of the proceeds from the previously announced master limited partnership initial public offering and sale of its Canadian subsidiary to fund the acquisition.

Pioneer estimates that the acquired acreage holds 38 million barrels oil equivalent (MMBOE) of net resource potential, consisting of 15 MMBOE of estimated proved reserves and an additional 23 MMBOE of resource potential. Approximately 20% of the proved reserves are developed with current net production of 700 barrels oil equivalent per day. The acquisition includes more than 600 potential drilling locations utilizing 40-acre spacing.