================================================================================ UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): April 4, 2005 UNOCAL CORPORATION ------------------------------------------------------ (Exact name of registrant as specified in its charter) DELAWARE 1-8483 95-3825062 ------------------------- ------------------------- --------------------------- (State or other jurisdiction (Commission (I.R.S. Employer of incorporation) File Number) Identification No.) 2141 Rosecrans Avenue, Suite 4000 El Segundo, California 90245 ------------------------------------------------------------ ------------------- (Address of Principal Executive Offices) (Zip Code) (310) 726-7600 ---------------------------------------------------- (Registrant's telephone number, including area code) Former name or former address, if changed since last report: N/A |_| Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) |X| 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 240.14d-2(b)) ================================================================================ EXPLANATORY NOTE This Amendment No. 1 to the Report on Form 8-K of Unocal Corporation is being filed to correct an error in the transmission of the 8-K filed on April 4, 2004, whereby Exhibit No. 99.1 was not properly included with the report, and is intended to amend and replace the aforementioned 8-K filing in its entirety. ITEM 8.01 OTHER EVENTS Unocal Corporation ("Unocal") and ChevronTexaco Corporation ("ChevronTexaco") have announced that they have entered into an agreement for ChevronTexaco to acquire Unocal. A copy of the joint press release of Unocal and ChevronTexaco is filed as Exhibit 99.1 hereto and is incorporated herein by reference. ITEM 9.01 FINANCIAL STATEMENTS AND EXHIBITS Exhibit No. Description ----------- ----------- 99.1 Joint Press Release, dated April 4, 2005 SIGNATURES 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 thereunto duly authorized. UNOCAL CORPORATION /s/ Terry G. Dallas ------------------------------- By: Terry G. Dallas Executive Vice President and Chief Financial Officer Date: April 4, 2005 EXHIBIT INDEX Exhibit No. Description ----------- ----------- 99.1 Joint Press Release, dated April 4, 2005