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): August 18, 1997





                                SIS Bancorp, Inc.
               (Exact name of registrant as specified in charter)




   Massachusetts                    000-20809                   04-3303264
  (State or other                (Commission file             (IRS employer
  jurisdiction of                    number)               identification no.)
  incorporation)


   1441 Main Street, Springfield, MA                             01102
(Address of principal executive offices)                       (Zip code)

                                 (413) 748-8000
               Registrant's telephone number, including area code






Item 5. Other Events

         On August 18, 1997, SIS Bancorp,  Inc. (the "Company")  entered into an
Agreement and Plan of Reorganization (the "Agreement") which provides for, among
other things, the acquisition (the  "Acquisition") of Glastonbury Bank and Trust
Company ("Glastonbury") by the Company.

         In  connection  with the  Acquisition,  the Board of  Directors  of the
Company has rescinded its prior  authorization,  granted in January of 1997, for
the Company to  repurchase up to 286,180  shares of its common stock,  effective
immediately. In the event that the Acquisition is not consummated, the Company's
Board of Directors would consider reinstating the share repurchase program.

         Glastonbury's  executive  officers  and  directors,  who,  according to
Glastonbury's  1997 proxy statement,  hold 428,037 shares of Glastonbury  common
stock,  or  approximately   23.39%  of  the  currently   outstanding  shares  of
Glastonbury common stock, have agreed in a separate letter agreement to vote all
of their  shares  in favor of the  Acquisition  Merger  and  against  any  other
competing transaction.

         A copy of the Company's  news release  relating to the  Acquisition  is
filed as Exhibit 99.1 to this report and is incorporated herein by reference.

         The Company has scheduled a telephonic  meeting with financial analysts
and  others  with  respect  to the  Acquisition.  Certain  financial  and  other
information  prepared for dissemination  during such meeting is filed as Exhibit
99.2 to this report.

      Cautionary Statements Relating to Certain Forward Looking Statements

         This Current  Report and the exhibits filed  herewith  contain  certain
forward-looking statements, including, but not limited to, statements concerning
plans,  objectives,  future events or  performance,  assumptions  and statements
relating to cost savings,  enhanced revenues, and accretion to reported earnings
that may be realized from the Acquisition as well as other  statements which are
other than statements of historical  fact. The Company cautions readers that the
following  important  factors,  among others, may have affected and could in the
future affect, the Company's actual results and could cause the Company's actual
results for subsequent  periods to differ materially from those expressed in any
forward-looking statement made by, or on behalf of, the Company herein.

         Economic  Conditions  and  Real  Estate  Risk.  The  Company's  lending
operations are concentrated primarily in western Massachusetts and Glastonbury's
lending  operations are concentrated in central  Connecticut.  As a result,  the
financial  condition and results of  operations of the combined  company will be
subject to the effects of changes in the  business  cycle and  downturns  in the
local,  regional  and  national  economies,  as well as other  general  economic
conditions, particularly, conditions that may affect residential real estate and
commercial lending in the market areas specified above. In an economic downturn,
there also tends to be a run-off in

                                   1                     





deposits.   If  economic  conditions  in  the  combined  company's  market  area
deteriorate,  the combined  company may not be able to  originate  the volume of
high quality  residential  mortgage loans and/or loans to small and medium-sized
businesses  or  achieve  the  level of  deposits  on which  the  forward-looking
statements are based.

         The Connecticut economy and its real estate market have showed signs of
stabilization over the past two years from the recessionary  levels of the early
1990's. Consequently Glastonbury's delinquencies, non-performing assets and loss
provisions  improved  from  earlier  periods.  The  forward-looking   statements
regarding  Glastonbury's  results  of  operations  assume  that the  Connecticut
economy  and real  estate  market will  remain  stable.  A worsening  of current
economic   conditions  or  a  significant  decline  in  real  estate  values  in
Connecticut   could  cause   actual   results  to  vary   materially   from  the
forward-looking statements.

         Similarly,  the Massachusetts economy and its real estate market showed
signs of  recovery  beginning  in 1994 from  earlier  recessionary  levels,  and
consequently  the  Company's  delinquencies,   non-performing  assets  and  loss
provisions  improved  from  earlier  periods.  The  forward-looking   statements
regarding the  Company's  results of  operations  assume that the  Massachusetts
economy  and real  estate  market will  remain  stable.  A worsening  of current
economic   conditions  or  a  significant  decline  in  real  estate  values  in
Massachusetts   could  cause  actual  results  to  vary   materially   from  the
forward-looking statements.

         Interest  Rate Risk.  The Company and  Glastonbury  both realize  their
income  principally from the  differential  between the interest earned on loans
and investment securities and the interest paid on deposits and borrowings.  The
net interest spreads of each organization are affected by the difference between
the   repricing   characteristics   of   their   interest-earning   assets   and
interest-bearing  liabilities.  Loan and investment volumes and yields, deposits
and borrowings are also affected by market interest  rates.  Changes in interest
rates could cause the combined  company's  earnings to vary  materially from the
forward-looking statements.

         Operational    Issues.   The    forward-looking    statements   utilize
Glastonbury's  internal  estimates  of growth  and  results  of  operations  and
generally  make  no  provision  for  any  possible   negative   effects  of  the
Acquisition.  In addition, the forward-looking  statements estimate certain cost
savings from the  consolidation  of various "back  office"  functions of the two
companies,  which may not  materialize  or which may be  delayed  as a result of
difficulties in consolidating  such functions.  To the extent that events differ
from the assumptions,  actual results of operations may vary materially from the
forward-looking statements.

         The ability of the combined company to operate efficiently, at least in
the short  term,  will be enhanced  by the  ability to retain  certain  existing
management  personnel.  If the  Company  is  not  able  to  retain  certain  key
management  personnel of Glastonbury,  the intended  consolidation  of the "back
office" functions of the two companies may be more time-consuming, difficult and
expensive, and may negatively affect the predicted cost savings.


                                        2





         The forward-looking statements assume that the deposit base of both the
Company and Glastonbury will remain substantially intact pending the Acquisition
and will grow at historical rates following the Acquisition.  To the extent that
the change in  ownership  of  Glastonbury  or other  factors  result in either a
temporary or long-term  loss of deposits,  actual results of operations may vary
materially from the forward-looking information presented.

         Competition.   The  Company  and  Glastonbury   both  face  significant
competition in their respective  markets.  Increasing  consolidation  within the
banking and financial services industry,  as well as increased  competition from
larger regional and out-of-state banking  organizations and nonbank providers of
various financial services,  may adversely affect the combined company's ability
to meet  its  financial  goals.  Many  of  these  large  competitors  have  more
significant   financial   resources,   larger  market  share  and  greater  name
recognition in the market area served by the combined  company than the combined
company  will  itself  have.  The  existence  of such  competitors  may  make it
difficult for the combined  company to achieve the financial  goals reflected in
the forward-looking statements.

         Laws and Regulations. The businesses of the Company and Glastonbury are
subject  to  federal  and state  regulation.  Changes  in laws and  regulations,
including federal and state banking laws and regulations, with which the Company
and its  subsidiaries  must comply,  and the associated costs of compliance with
such  laws  and  regulations,  could  cause  actual  results  to vary  from  the
forward-looking statements. Changes in accounting policies and practices, as may
be  adopted  by  applicable  regulatory  agencies  as well  as by the  Financial
Accounting  Standards  Board,  or in the  Company's  post-closing  organization,
compensation  and benefit plans also could cause actual results to vary from the
forward-looking statements.

Item 7.  FINANCIAL STATEMENTS AND EXHIBITS.

(c)      Exhibits

         99.1     News Release of the Company, dated August 18, 1997

         99.2     Analyst Meeting Materials.



                                        3




                                   SIGNATURES

         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
SIS Bancorp,  Inc. has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                  SIS BANCORP, INC.


Date: August 18, 1997             By:/s/ John F. Treanor
                                       Name:   John F. Treanor
                                       Title:  Executive Vice President
                                               and Chief Financial Officer








                                        4