UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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 20, 2005 BOK FINANCIAL CORPORATION (Exact name of registrant as specified in its charter) Oklahoma 000-19341 73-1373454 -------- --------- ---------- (State or other jurisdiction (Commission (IRS Employer of incorporation) File Number) Identification No.) Bank of Oklahoma Tower, Boston Avenue at Second Street, Tulsa, Oklahoma 74172 (Address of principal executive offices) Registrant's telephone number, including area code: (918) 588-6000 _____________________N/A___________________________ (Former name or former address, if changes 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)). INFORMATION TO BE INCLUDED IN THE REPORT ITEM 7.01 Regulation FD Disclosure On May 20, 2005, Standard & Poor's Rating Services raised its long-term counterparty credit rating on BOK Financial Corporation (BOKF) to BBB+ from BBB. At the same time, Standard & Poor's raised its long-term counterparty credit rating on BOKF's subsidiary, Bank of Oklahoma, N.A., to A- from BBB+. The outlooks for both BOKF and its subsidiary were revised to stable from positive. 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. BOK FINANCIAL CORPORATION By: /s/ Steven E. Nell -------------------------------- Steven E. Nell Executive Vice President Chief Financial Officer Date: May 20, 2005