content: <PAGE>
  
                 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 21, 1999
  
  
  
                               GREATER BAY BANCORP
             (Exact name of registrant as specified in its charter)
  
           California                                          77-0387041
  (State or other jurisdiction of                             (IRS Employer
   incorporation or organization)                           Identification No.)
  
                        COMMISSION FILE NUMBER:  0-25034
  
              2860 West Bayshore Road, Palo Alto, California 94303
            (Address of principal executive offices)       (Zip Code)
  
                                 (650) 813-8200
              (Registrant's telephone number, including area code)
  
  
  <PAGE>
  
  ITEM 5.  OTHER ITEMS.
  
       On May 21, 1999, Greater Bay Bancorp (the "Registrant") completed a merger
  with Bay Area Bancshares ("BA Bancshares"), the holding company of Bay Area Bank
  ("BAB") which was accounted for as a pooling-of-interests. Shareholders of BA
  Bancshares received 1.38682 shares of the Registrant's Common Stock for each
  outstanding share of BA Bancshares Common Stock. A total of 1,399,321 shares
  were issued in the transaction.
  
       The supplemental consolidated financial statements filed herewith have been
  prepared accounting for the merger using the pooling-of-interests method of
  accounting. Upon publication of the Company's financial statements for a period
  which includes May 21, 1999, their supplemental consolidated financial
  statements will become the historical financial statements of the Company.
  
  
  ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS.
  
  EXHIBIT
    NO.                    EXHIBITS
  -------                  -------
  23.1      Consent of PricewaterhouseCoopers LLP
  
  27.1      Restated Financial Data Schedules for quarters ended September 30,
            1998 and June 30, 1998 (included in electronic filing through EDGAR)
  
  27.2      Restated Financial Data Schedules for quarters ended March 31, 1998
            and December 31, 1997 (included in electronic filing through EDGAR)
  
  27.3      Restated Financial Data Schedules for quarters ended September 30,
            1997 and June 30, 1997 (included in electronic filing through EDGAR)
  
  27.4      Restated Financial Data Schedules for quarters ended March 31, 1997
            (included in electronic filing through EDGAR)
  
  27.5      Restated Financial Data Schedules for the years ended December 31,
            1998 and 1997 (included in electronic filing through EDGAR)
  
  27.6      Restated Financial Data Schedules for the year ended December 31, 1996
            (included in electronic filing through EDGAR)
  
  27.7      Restated Financial Data Schedules for quarters ended March 31, 1999
            and December 31, 1998 (included in electronic filing through EDGAR)
  
  99.1      Supplemental Consolidated Financial Statements and Supplementary Data
            (restated to include BA Bancshares and BAB)
  
            For the Years Ended December 31, 1998, 1997 and 1996:
  
            Selected Financial Data
            Management's Discussion and Analysis
            Consolidated Balance Sheet as of December 31, 1998 and 1997
            Consolidated Statements of Operations for the Years Ended December 31,
            1998, 1997 and 1996
            Consolidated Statements of Shareholders' Equity for the Years Ended
            December 31, 1998, 1997 and 1996
            Notes to Consolidated Financial Statements
            Report of Independent Accountants
  
  99.2      Supplemental Consolidated Financial Statements and Supplementary Data
            (restated to include BA Bancshares and BAB)
  
            For the Quarters Ended March 31, 1999 and 1998:
  
            Management's Discussion and Analysis
            Consolidated Balance Sheet as of March 31, 1999 and December 31, 1998
            Consolidated Statements of Operations for the Quarters Ended March
            31, 1999 and 1998
            Notes to Consolidated Financial Statements
  
                                                                                 2
  <PAGE>
  
                                   SIGNATURES
  
  IN ACCORDANCE WITH THE REQUIREMENTS OF THE SECURITIES AND EXCHANGE ACT OF 1934,
  AS AMENDED, THE REGISTRANT HAS CAUSED THIS REPORT TO BE SIGNED ON ITS BEHALF BY
  THE UNDERSIGNED THEREUNTO DULY AUTHORIZED.
  
  GREATER BAY BANCORP
  (Registrant)
  
  By:
  
  /s/ STEVEN C. SMITH
  -------------------
      Steven C. Smith
      Executive Vice President, Chief Administrative Officer and
      Chief Financial Officer
  
  
  
  Date:  July 1, 1999
  
                                                                                 3
  <PAGE>
  
  
                                  EXHIBIT INDEX
  
  Exhibits.
  
  23.1      Consent of PricewaterhouseCoopers LLP
  
  27.1      Restated Financial Data Schedules for quarters ended September 30,
            1998 and June 30, 1998 (included in electronic filing through EDGAR)
  
  27.2      Restated Financial Data Schedules for quarters ended March 31, 1998
            and December 31, 1997 (included in electronic filing through EDGAR)
  
  27.3      Restated Financial Data Schedules for quarters ended September 30,
            1997 and June 30, 1997 (included in electronic filing through EDGAR)
  
  27.4      Restated Financial Data Schedules for quarters ended March 31, 1997
            (included in electronic filing through EDGAR)
  
  27.5      Restated Financial Data Schedules for the years ended December 31,
            1998 and 1997 (included in electronic filing through EDGAR)
  
  27.6      Restated Financial Data Schedules for the year ended December 31, 1996
            (included in electronic filing through EDGAR)
  
  27.7      Restated Financial Data Schedules for quarters ended March 31, 1999
            and December 31, 1998 (included in electronic filing through EDGAR)
  
  99.1      Supplemental Consolidated Financial Statements and Supplementary Data
            (restated to include BA Bancshares and BAB)
  
            For the Years Ended December 31, 1998, 1997 and 1996:
  
            Selected Financial Data
            Management's Discussion and Analysis
            Consolidated Balance Sheet as of December 31, 1998 and 1997
            Consolidated Statements of Operations for the Years Ended December
            31, 1998, 1997 and 1996
            Consolidated Statements of Shareholders' Equity for the Years Ended
            December 31, 1998, 1997 and 1996
            Notes to Consolidated Financial Statements
            Report of Independent Accountants
  
  99.2      Supplemental Consolidated Financial Statements and Supplementary Data
            (restated to include BA Bancshares and BAB)
  
            For the Quarters Ended March 31, 1999 and 1998:
  
            Management's Discussion and Analysis
            Consolidated Balance Sheet as of March 31, 1999 and December 31, 1998
            Consolidated Statements of Operations for the Quarters Ended March
            31, 1999 and 1998
            Notes to Consolidated Financial Statements
  
                                                                                 4
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metadata_filer: {"company-data": {"conformed-name": "GREATER BAY BANCORP", "cik": "0000775473", "assigned-sic": "6021", "irs-number": "770387041", "state-of-incorporation": "CA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-25034", "film-number": "99658027"}, "business-address": {"street1": "2860 WEST BAYSHORE ROAD", "city": "PALO ALTO", "state": "CA", "zip": "94303", "phone": "4153751555"}, "mail-address": {"street1": "2860 BAYSHORE ROAD", "street2": "420 COWPER ST", "city": "PALO ALTO", "state": "CA", "zip": "943011504"}, "former-company": [{"former-conformed-name": "MID PENINSULA BANCORP", "date-changed": "19941031"}, {"former-conformed-name": "SAN MATEO COUNTY BANCORP", "date-changed": "19920703"}]}
text: 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 21, 1999
  
                               GREATER BAY BANCORP
             (Exact name of registrant as specified in its charter)
  
           California                                          77-0387041
  (State or other jurisdiction of                             (IRS Employer
   incorporation or organization)                           Identification No.)
  
                        COMMISSION FILE NUMBER:  0-25034
  
              2860 West Bayshore Road, Palo Alto, California 94303
            (Address of principal executive offices)       (Zip Code)
  
                                 (650) 813-8200
              (Registrant's telephone number, including area code)
  ITEM 5.  OTHER ITEMS.
  
       On May 21, 1999, Greater Bay Bancorp (the "Registrant") completed a merger
  with Bay Area Bancshares ("BA Bancshares"), the holding company of Bay Area Bank
  ("BAB") which was accounted for as a pooling-of-interests. Shareholders of BA
  Bancshares received 1.38682 shares of the Registrant's Common Stock for each
  outstanding share of BA Bancshares Common Stock. A total of 1,399,321 shares
  were issued in the transaction.
  
       The supplemental consolidated financial statements filed herewith have been
  prepared accounting for the merger using the pooling-of-interests method of
  accounting. Upon publication of the Company's financial statements for a period
  which includes May 21, 1999, their supplemental consolidated financial
  statements will become the historical financial statements of the Company.
  
  ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS.
  
  EXHIBIT
    NO.                    EXHIBITS
  -------                  -------
  23.1      Consent of PricewaterhouseCoopers LLP
  
  27.1      Restated Financial Data Schedules for quarters ended September 30,
            1998 and June 30, 1998 (included in electronic filing through EDGAR)
  
  27.2      Restated Financial Data Schedules for quarters ended March 31, 1998
            and December 31, 1997 (included in electronic filing through EDGAR)
  
  27.3      Restated Financial Data Schedules for quarters ended September 30,
            1997 and June 30, 1997 (included in electronic filing through EDGAR)
  
  27.4      Restated Financial Data Schedules for quarters ended March 31, 1997
            (included in electronic filing through EDGAR)
  
  27.5      Restated Financial Data Schedules for the years ended December 31,
            1998 and 1997 (included in electronic filing through EDGAR)
  
  27.6      Restated Financial Data Schedules for the year ended December 31, 1996
            (included in electronic filing through EDGAR)
  
  27.7      Restated Financial Data Schedules for quarters ended March 31, 1999
            and December 31, 1998 (included in electronic filing through EDGAR)
  
  99.1      Supplemental Consolidated Financial Statements and Supplementary Data
            (restated to include BA Bancshares and BAB)
  
            For the Years Ended December 31, 1998, 1997 and 1996:
  
            Selected Financial Data
            Management's Discussion and Analysis
            Consolidated Balance Sheet as of December 31, 1998 and 1997
            Consolidated Statements of Operations for the Years Ended December 31,
            1998, 1997 and 1996
            Consolidated Statements of Shareholders' Equity for the Years Ended
            December 31, 1998, 1997 and 1996
            Notes to Consolidated Financial Statements
            Report of Independent Accountants
  
  99.2      Supplemental Consolidated Financial Statements and Supplementary Data
            (restated to include BA Bancshares and BAB)
  
            For the Quarters Ended March 31, 1999 and 1998:
  
            Management's Discussion and Analysis
            Consolidated Balance Sheet as of March 31, 1999 and December 31, 1998
            Consolidated Statements of Operations for the Quarters Ended March
            31, 1999 and 1998
            Notes to Consolidated Financial Statements
  
                                                                                 2
  SIGNATURES
  
  IN ACCORDANCE WITH THE REQUIREMENTS OF THE SECURITIES AND EXCHANGE ACT OF 1934,
  AS AMENDED, THE REGISTRANT HAS CAUSED THIS REPORT TO BE SIGNED ON ITS BEHALF BY
  THE UNDERSIGNED THEREUNTO DULY AUTHORIZED.
  
  GREATER BAY BANCORP
  (Registrant)
  
  By:
  
  /s/ STEVEN C. SMITH
  -------------------
      Steven C. Smith
      Executive Vice President, Chief Administrative Officer and
      Chief Financial Officer
  
  Date:  July 1, 1999
  
                                                                                 3
  EXHIBIT INDEX
  
  Exhibits.
  
  23.1      Consent of PricewaterhouseCoopers LLP
  
  27.1      Restated Financial Data Schedules for quarters ended September 30,
            1998 and June 30, 1998 (included in electronic filing through EDGAR)
  
  27.2      Restated Financial Data Schedules for quarters ended March 31, 1998
            and December 31, 1997 (included in electronic filing through EDGAR)
  
  27.3      Restated Financial Data Schedules for quarters ended September 30,
            1997 and June 30, 1997 (included in electronic filing through EDGAR)
  
  27.4      Restated Financial Data Schedules for quarters ended March 31, 1997
            (included in electronic filing through EDGAR)
  
  27.5      Restated Financial Data Schedules for the years ended December 31,
            1998 and 1997 (included in electronic filing through EDGAR)
  
  27.6      Restated Financial Data Schedules for the year ended December 31, 1996
            (included in electronic filing through EDGAR)
  
  27.7      Restated Financial Data Schedules for quarters ended March 31, 1999
            and December 31, 1998 (included in electronic filing through EDGAR)
  
  99.1      Supplemental Consolidated Financial Statements and Supplementary Data
            (restated to include BA Bancshares and BAB)
  
            For the Years Ended December 31, 1998, 1997 and 1996:
  
            Selected Financial Data
            Management's Discussion and Analysis
            Consolidated Balance Sheet as of December 31, 1998 and 1997
            Consolidated Statements of Operations for the Years Ended December
            31, 1998, 1997 and 1996
            Consolidated Statements of Shareholders' Equity for the Years Ended
            December 31, 1998, 1997 and 1996
            Notes to Consolidated Financial Statements
            Report of Independent Accountants
  
  99.2      Supplemental Consolidated Financial Statements and Supplementary Data
            (restated to include BA Bancshares and BAB)
  
            For the Quarters Ended March 31, 1999 and 1998:
  
            Management's Discussion and Analysis
            Consolidated Balance Sheet as of March 31, 1999 and December 31, 1998
            Consolidated Statements of Operations for the Quarters Ended March
            31, 1999 and 1998
            Notes to Consolidated Financial Statements
  
                                                                                 4