UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ------------------------ FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 25, 2006 ------------------------ PIONEER NATURAL RESOURCES COMPANY (Exact name of registrant as specified in its charter) Delaware 1-13245 75-2702753 (State or other (Commission File Number) (I.R.S. Employer jurisdiction of incorporation) Identification Number) 5205 N. O'Connor Blvd. 75039 Suite 900 (Zip code) Irving, Texas (Address of principal executive offices) Registrant's telephone number, including area code: (972) 444-9001 Not applicable (Former name or former address, if changed since last report) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the Registrant under any of the following provisions: [ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) [ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) [ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) [ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Item 7.01. Regulation FD Disclosure. Pioneer Natural Resources Company (the "Company") filed as exhibits to its Form 10-K for the year ended December 31, 2005 the certifications required under section 302 of the Sarbanes-Oxley Act of 2002. Pursuant to the New York Stock Exchange ("NYSE") Listed Company Manual, the foregoing disclosure was required to be made in the Company's annual report to shareholders but was inadvertently omitted. This filing is being made at the request of the NYSE to remedy such omission. SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PIONEER NATURAL RESOURCES COMPANY /s/ Darin G. Holderness ------------------------------------------- Darin G. Holderness Vice President and Chief Accounting Officer Dated: May 25, 2006