================================================================================ 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 October 6, 2006 Date of Report (Date of earliest event reported) UNITED SECURITY BANCSHARES (Exact Name of Registrant as Specified in its Charter) California (State or Other Jurisdiction of Incorporation) 000-32987 91-2112732 (Commission File Number) (IRS Employer Identification No.) 1525 E. Shaw Avenue 93710 (Address of Principal Executive Office) (Zip Code) 559-248-4943 (Registrant's Telephone Number, Including Area Code) 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: [X] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) [ ] Soliciting material pursuant to Rule 14a12 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 1.01 ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT. On October 6, 2006, United Security Bancshares and Legacy Bank, N.A. announced today the signing of a definitive merger agreement providing for the merger of Legacy Bank, N.A. with and into United Security Bank, a wholly owned subsidiary of USB. A copy of such press release is attached, and incorporated herein by reference as Exhibit 99.1 ITEM 9.01 FINANCIAL STATEMENTS AND EXHIBITS. (d) Exhibits. EXHIBIT # 10.28 Agreement and Plan of Reorganization and Merger EXHIBIT # 99.1 Press release of United Security Bancshares dated October 6, 2006 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 hereunto duly authorized. United Security Bancshares Date: October 6, 2006 By: /s/ Ken Donahue ----------------------- Senior Vice President & Chief Financial Officer EXHIBIT INDEX EXHIBIT # DESCIPTION --------- ------------------------------------------------------------------ EXHIBIT # 10.28 Agreement and Plan of Reorganization and Merger EXHIBIT # 99.1 Press release of United Security Bancshares dated October 6, 2006