SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                   FORM 10-K/A
                                  (Amendment 1)
(Mark One)
x        ANNUAL  REPORT  PURSUANT  TO  SECTION  13 OR  15(d)  OF THE  SECURITIES
         EXCHANGE ACT OF 1934 for the fiscal year ended December 31, 1997
                                       OR
o        TRANSITION  REPORT  PURSUANT  TO SECTION 13 OR 15(d) OF THE  SECURITIES
         EXCHANGE ACT OF 1934

Commission file number: 000-20809

                                SIS BANCORP, INC.
             (Exact Name of Registrant as Specified in its Charter)

Massachusetts                                                04-3303264
(State or other jurisdiction of                            (I.R.S. Employer
incorporation or organization)                             Identification No.)

1441 Main Street
Springfield, Massachusetts                             01102
(Address of Principal Executive Offices)             (Zip Code)

                                 (413) 748-8000
              (Registrant's Telephone Number, Including Area Code)

           SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:

                                      None

           SECURITIES REGISTERED PURSUANT TO SECTION 12(g) OF THE ACT:

                               Title of Each Class
                     Common Stock, par value $0.01 per share

         Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days. Yes X No ____

         Indicate by check mark if disclosure of delinquent  filers  pursuant to
Item 405 of Regulation S-K is not contained  herein,  and will not be contained,
to the best of the  registrant's  knowledge,  in definitive proxy or information
statements  incorporated  by  reference  in Part  III of this  Form  10-K or any
amendment to this Form 10-K. [ X ]

         The aggregate  market value of the voting stock held by  non-affiliates
of the registrant, based on the closing sale price of March 6, 1998, as reported
by NASDAQ, was $267,882,500.

         Indicate the number of shares  outstanding of the  registrant's  common
stock, as of the latest practicable date: 6,957,987 shares as of March 6, 1998.

                       DOCUMENTS INCORPORATED BY REFERENCE

Portions of the SIS Bancorp,  Inc.  Proxy  Statement  for the Annual  Meeting of
Stockholders  to be held on May 7, 1998 are  incorporated by reference into Part
III of this Form 10-K.
<PAGE>
Part IV

ITEM 14.  EXHIBITS, FINANCIAL SCHEDULES AND REPORTS ON FORM 8-K

 (a) Contents:

         (1)      Financial Statements: All Financial Statements are included as
                  Part II,  Item 8 of this  Report.  The  index is on page 40 of
                  this Report.

         (2)      Financial   Statement   Schedules:   All  Financial  Statement
                  Schedules are included as Part II, Item 8 of this Report.  The
                  index is on page 40 of this Report.

(b) Reports on Form 8-K:  During the fourth  quarter of 1997, the following Form
8-K's were filed:

         o        Form 8-K  filed on  October  22,  1997  relating  to the press
                  release  issued  on  October  22,  1997  containing  unaudited
                  financial  information  and announcing a cash dividend for the
                  quarter ended  September 30, 1997 and  containing  information
                  relating to the  previously  announced  acquisition of GBT and
                  the acceleration of systems conversions and full "back office"
                  integration of GBT with the Company.

         o        Form 8-K filed on December 31, 1997  announcing the completion
                  on December 17, 1997 of the  acquisition of GBT by the Company
                  pursuant to the  Agreement  and Plan of  Reorganization  dated
                  August 18, 1997.

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<PAGE>
(c) Exhibits:

Exhibit No.       Exhibit                                              Location

(3)(a).           Articles of Organization of SIS Bancorp, Inc.            (1)

(3)(b).           By-laws of SIS Bancorp, Inc.                             (1)

4(a).             Specimen Common Stock Certificate                        (4)

10.               Material Contracts
(a) Employment agreements for Messrs. F. William Marshall,  Jr., Frank
W. Barrett,  B. John Dill, John F. Treanor,  Henry J.  McWhinnie,  Ms.
Jeanne Rinaldo, Mr. Michael E. Tucker                                      (1)

(b) Employment agreements for Messrs. Gilbert F. Ehmke and Christopher
A. Sinton.                                                                 (2)

(c)  Employment agreement for Mr. J. Gilbert Soucie                         *

(d) Director and Management Stock Option Plan, as amended.                 (4)

(e) Director and Management Restricted Stock Plan, as amended.             (4)

(f) Rights  Agreement,  dated  January  22,  1997 by and  between  the
Company and ChaseMellon Shareholder Services, as Rights Agent              (3)

21.      Subsidiaries of the Registrant                                     *

23.      Consent of Price Waterhouse, LLP.                                  *

27.      Financial Data Schedules

27.1     Financial Data Schedule for year ended December 31, 1997           *

27.2     Financial Data Schedule restated for year ended December 31, 1996  *

27.3     Financial Data Schedules  restated for periods ended June 30,
         1996,  September 30, 1996,  March 31, 1997, June 30, 1997 and
         September 30, 1997

Locations of Exhibits if not attached hereto:

(1) Exhibit is incorporated by reference to the Form 8-A Registration  Statement
filed by the Company with the Securities and Exchange Commission ("SEC") on June
21, 1996. 
(2) Exhibit is incorporated by reference to the Form 10-Q for the quarter ending
June 30, 1996.
(3) Exhibit is incorporated by reference to the Form 8-A Registration Sta tement
filed by the Company with the SEC on January 23, 1997.
(4) Exhibit is  incorporated  by  reference  to the Form 10-K filed for the year
ended December 31, 1996.

 *  Previously filed

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<PAGE>
                                   SIGNATURES



Pursuant to the requirements of the Section 13 of the Securities Exchange Act of
1934,  the Bank has duly  caused  this  Report to be signed on its behalf by the
undersigned, thereunto duly authorized.



                                        SPRINGFIELD INSTITUTION FOR SAVINGS


April 28, 1998                          /s/  John F. Treanor
Date                                    John F. Treanor
                                        Executive Vice President,
                                        Chief Financial Officer, Chief
                                        Operating Officer and Treasurer

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