<Page> SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 02549 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): DECEMBER 19, 2002 SEACOAST FINANCIAL SERVICES CORPORATION (Exact name of registrant as specified in its charter) MASSACHUSETTS 000-25077 04-1659040 (State or other jurisdiction (Commission (IRS Employer of incorporation) File Number) Identification No.) ONE COMPASS PLACE, NEW BEDFORD, MASSACHUSETTS 02740 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (508) 984-6000 NOT APPLICABLE (Former Name or Former Address, if Changed Since Last Report) ITEM 5. OTHER EVENTS. On December 19, 2002, Seacoast Financial Services Corporation, a Massachusetts corporation ("Seacoast"), and Bay State Bancorp, Inc., a Delaware corporation ("Bay State"), announced that they have entered into an Agreement and Plan of Merger pursuant to which Seacoast will acquire Bay State (the "Agreement"). The Agreement provides for the merger of Bay State with and into a wholly owned subsidiary of Seacoast and the subsequent merger of Bay State Federal Savings Bank with and into Compass Bank for Savings, Seacoast's main banking subsidiary. Pursuant to the Agreement, each share of Bay State common stock, par value $0.01 per share, issued and outstanding immediately prior to the effective time of the merger will be converted into the right to receive at the election of the holder either (i) $27.00 in cash, without interest, (ii) 1.257 shares of Seacoast common stock, or (iii) a combination of Seacoast common stock and cash, subject to the requirement that 55% of the Bay State shares be exchanged for Seacoast stock. The Agreement contains allocation and proration procedures to achieve this result. Bay State will have the ability to terminate the Agreement if the price of Seacoast common stock declines by more than 10% and underperforms a peer group of companies by more than 20% over a designated measurement period unless Seacoast increases the exchange ratio for converting shares of Bay State common stock to Seacoast stock in accordance with a formula specified in the Agreement. Consummation of the merger is subject to the satisfaction of certain conditions, including approval of the Agreement by the stockholders of Bay State and approval by the appropriate regulatory agencies. Officers and directors of Bay State holding approximately 536,000 shares of Bay State common stock have agreed to vote their shares in favor of the transaction. The Agreement provides for a termination fee of $6.0 million. The termination fee would be payable by Bay State in the event the Agreement is terminated as a result of Bay State's willful or intentional breach of the Agreement or if Bay State enters into an agreement for or consummates another business combination or similar transaction with another party. The termination fee would be payable by Seacoast in the event the Agreement is terminated as a result of Seacoast's willful or intentional breach of the Agreement. The foregoing description is qualified in its entirety by reference to the Agreement, a copy of which is attached hereto as Exhibit 2.1 and incorporated by reference in response to this Item 5. ITEM 7. FINANCIAL STATEMENTS AND EXHIBITS. (a) Not Applicable. (b) Not Applicable. (c) Exhibits: The following exhibits are filed as part of this report: 2 EXHIBIT NO. DESCRIPTION 2.1 Agreement and Plan of Merger, dated as of December 19, 2002 by and between Seacoast Financial Services Corporation, Seacoast Merger Sub, Inc. and Bay State Bancorp, Inc. 10.1 Form of Voting Agreement (attached as Annex A to Exhibit 2.1) 10.2 Payments and Waiver Agreement by and among Seacoast Financial Services Corporation, Bay State Bancorp, Inc., Bay State Federal Savings Bank and John F. Murphy 10.3 Payments and Waiver Agreement by and among Seacoast Financial Services Corporation, Bay State Bancorp, Inc., Bay State Federal Savings Bank and Denise Renaghan 10.4 Payments and Waiver Agreement by and among Seacoast Financial Services Corporation, Bay State Bancorp, Inc., Bay State Federal Savings Bank and Michael Gilles 10.5 Consulting and Non-Competition Agreement between Seacoast Financial Services Corporation and John F. Murphy 10.6 Non-Competition Agreement between Seacoast Financial Services Corporation and Denise Renaghan 99.1 Press Release dated December 19, 2002.* - ---------------- * Incorporated by reference from Seacoast Financial's filing with the Commission pursuant to Rule 425 under the Securities Act of 1933 on December 20, 2002. 3 <Page> 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, thereunto duly authorized. SEACOAST FINANCIAL SERVICES CORPORATION Dated: December 23, 2002 By: /s/ Kevin G. Champagne -------------------------------------- Kevin G. Champagne President and Chief Executive Officer 4