SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM 8-A

                For Registration of Certain Classes of Securities
                    Pursuant to Section 12(b) or 12(g) of the
                         Securities Exchange Act of 1934

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

         Massachusetts                                  04-3303264
(State of Incorporation or Organization)              (I.R.S. Employer
                                                      Identification no.)


1441 Main Street
Springfield, Massachusetts                                  01102
(Address of principal executive office)                   (zip code)


If this Form relates to the                If this Form relates to the
registration of a class of                 registration of a class of
debt securities and is effective           debt securities and is to become
upon filing pursuant to General            effective simultaneously with the
Instruction A(c)(1) please check           effectiveness of a concurrent
the following box. / /                     registration statement under the 
                                           Securities Act of 1933 pursuant
                                           to General Instruction A(c)(2)
                                           please check the following box. / /



        Securities to be registered pursuant to Section 12(b) of the Act:


            Title of Each Class              Name of Each Exchange on Which
            to be so Registered              Each Class is to be Registered

                   None




        Securities to be registered pursuant to Section 12(g) of the Act:

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






Item 1.  Description of Registrant's Securities to be Registered.

General

     Pursuant to an Agreement and Plan of Reorganization dated as of January 31,
1996 (the "Plan of Reorganization") between Springfield Institution for Savings,
a Massachusetts chartered stock savings bank (the "Bank") and SIS Bancorp, Inc.,
a newly-formed  Massachusetts corporation organized at the direction of the Bank
(the "Company"),  the Company will acquire all of the outstanding  common stock,
par value $1.00 per share,  of the Bank other than shares held by  stockholders,
if any, exercising  dissenters' appraisal rights, in a share-for-share  exchange
for the common stock, par value $.01 per share, of the Company ("Common Stock").
The Bank will thereby  become a  wholly-owned  subsidiary of the Company and the
Bank's  stockholders  will  become,  subject to their  exercise  of  dissenters'
appraisal   rights,   stockholders  of  the  Company.   Under  the  Articles  of
Organization  of  the  Company  (the  "Articles"),   as  amended  prior  to  the
consummation  of the Plan of  Reorganization,  the Company will be authorized to
issue up to  25,000,000  shares of Common  Stock and up to  5,000,000  shares of
preferred stock, par value $0.01 per share.

Preferred Stock

     The Board of  Directors  of the Company is  authorized  to issue  shares of
preferred  stock  in  series  and  to  fix  the  voting  powers,   designations,
preferences,  or other special  rights of the shares of each such series and the
qualifications, limitations, and restrictions thereon. The issuance of preferred
stock by the Company is subject to the approval of a majority  vote of the Board
of  Directors  of the  Company.  Preferred  stock issued by the Company may rank
prior to the Common Stock as to dividend rights, or liquidation preferences,  or
both, may have full or limited voting rights  (including  multiple voting rights
and voting  rights as a class),  and may be  convertible  into  shares of Common
Stock.

Common Stock

     Voting  Rights.  Stockholders  are  entitled  to one vote per  share on any
matters  subject to stockholder  approval,  including the election of Directors.
The  Articles  do not  provide  for  cumulative  voting in  connection  with the
election of Directors,  and therefore  holders of a majority of the Common Stock
will be able to elect all of the  Directors  standing for election in each year,
subject to the rights of the holders of shares of preferred  stock,  if and when
issued.

      Preemptive Rights. Holders of Common Stock have no preemptive rights as to
the  purchase  of any  shares  issued  in the  future.  Therefore,  the Board of
Directors may sell shares of capital  stock  without first  offering them to the
then stockholders of the Company.

     Assessability. Under Massachusetts law, Common Stock is non-assessable.

     Dividend  Rights;  Repurchase  or  Redemption  of Shares.  A  Massachusetts
business  corporation,  such as the Company,  may pay dividends or repurchase or
redeem its shares of capital stock; however, a director who votes to authorize a
dividend,  repurchase or redemption  which is in violation of the  corporation's
articles of  organization  or which  renders the  corporation  insolvent  may be
jointly  and  severally  liable  for  such  improper  dividend,   repurchase  or
redemption.  Stockholders  to whom a  corporation  makes  any such  distribution
(except a distribution of stock of the  corporation),  if the corporation is, or
is thereby rendered,  insolvent, are liable to the corporation for the amount of
such  distribution  made, or for the amount of such  distribution  which exceeds
that which could have been made without rendering the corporation insolvent, but
in either  event only to the extent of the amount paid or  distributed  to them,
respectively.

     It is the policy of the Federal  Reserve Board that bank holding  companies
should  pay cash  dividends  on common  stock  only out of the past  year's  net
income,  and only if  prospective  earnings  retention  is  consistent  with the
organization's  expected future needs.  The policy further  provides that a bank
holding  company should not maintain a level of cash  dividends that  undermines
the bank  holding  company's  ability  to serve as a source of  strength  to its
subsidiary  banks.  The Federal Reserve Board also requires by regulation that a
bank holding company seeking to purchase or redeem any of its equity  securities
must provide prior notice to the appropriate regional Federal Reserve

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Bank, which may disapprove of such proposed purchase or redemption, if the gross
consideration  for such purchase or  redemption,  when  aggregated  with the net
consideration  paid by the holding company for all such purchases or redemptions
during  the  preceding  twelve  months,  exceeds  10% of the  holding  company's
consolidated net worth,  except that such prior notice requirements do not apply
to any holding  company that is "well  capitalized"  in accordance  with Federal
Reserve  Board  regulations,  has received a composite  "1" or "2" rating in its
most recent examination and is not subject to any unresolved regulatory issues.

     Any issuance of preferred stock with a preference over Company Common Stock
as to dividends may affect the dividend rights of Common Stock holders.

Directors

     Number and  Staggered  Terms.  The By-laws of the Company  (the  "By-laws")
provide that,  subject to the rights of holders of preferred  stock, if and when
issued,  a majority of the total number of Directors that the Company would have
if there were no vacancies  (the "Whole  Board") shall fix from time to time the
number of Directors  of the  Company,  which number will not in any case be less
than three, unless at the time there is an Interested  Stockholder in which case
a majority vote of the Continuing Directors is also required to fix such number.
The Board of  Directors  of the  Company  will  initially  be  composed of seven
Directors.  The Articles  provide for three classes of Directors  with one class
elected each year for three year  staggered  terms,  so that  ordinarily no more
than approximately one-third of the Directors will stand for election in any one
year, and that there will be no cumulative  voting in the election of Directors.
The term  "Interested  Stockholder" is defined in the Articles to mean generally
any beneficial owner of more than 4.9% of the outstanding  voting stock or, from
and after February 7, 1998, 10% of the  outstanding  voting stock of the Company
and certain  assignees  of such  Interested  Stockholder.  The term  "Continuing
Directors"  is defined in the Articles to mean  generally  Directors and certain
successor Directors who are not affiliates of any Interested Stockholder and who
were  Directors  prior to the time  that any  Interested  Stockholder  became an
Interested Stockholder.

     Removal.  The Articles  provide that  Directors may be removed from office,
but only for  cause,  and then  only by the  affirmative  vote of not less  than
eighty percent of the outstanding  shares entitled to vote at a duly constituted
meeting of  stockholders.  The Articles define cause to mean only the following:
(i) conviction of a felony,  (ii) declaration of unsound mind by order of court,
(iii) gross  dereliction  of duty,  (iv)  commission of an act  involving  moral
turpitude,  or  (v)  commission  of  an  action  which  constitutes  intentional
misconduct or a knowing  violation of law if such action in either event results
both in an improper  substantial  personal  benefit and a material injury to the
Company.

     Vacancies.  The By-laws provide that any vacancy  occurring on the Board of
Directors of the Company,  including  vacancies resulting from an enlargement of
the Board,  shall be filled solely by the affirmative  vote of a majority of the
remaining Directors,  unless at the time there is an Interested Stockholder,  in
which case the  affirmative  vote of a majority of the  Continuing  Directors is
required.  Any  Director  of the  Company so chosen  would  hold  office for the
remainder  of the term of the class of  Directors to which the Director has been
elected.

Meetings of Stockholders

     The Articles  provide that a special meeting of stockholders  may be called
only by the President,  or by a majority of the Whole Board, provided that if at
the time of any such call there is an  Interested  Stockholder,  such call shall
also require the affirmative vote of a majority of the Continuing Directors then
in office.  The Articles  also provide that only those  matters set forth in the
call of the special  meeting  may be  considered  or acted upon at such  special
meeting, unless otherwise provided by law.

     The By-laws set forth certain advance notice and informational requirements
and time  limitations  on any Director  nomination  or any new business  which a
stockholder  wishes to propose for  consideration  at a meeting of stockholders.
Any such  nomination  or new business,  to be timely,  shall be delivered to, or
mailed and received at, the principal  executive offices of the Company not less
than 70 days  nor  more  than 90 days  prior  to the  first  anniversary  of the
preceding year's annual meeting, provided that in the event that the date of the
annual  meeting is  advanced  by more than  twenty  days or delayed by more than
seventy days from such anniversary date, notice by the stockholder to be timely

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must be so  delivered  not earlier than the  ninetieth  day prior to such annual
meeting and not later than the close of business on the later of the  seventieth
day prior to such  annual  meeting or the tenth day  following  the day on which
public  announcement of the date of such meeting is first made.  Notwithstanding
the above,  in the event that the number of directors to be elected to the Board
of Directors is increased and there is no public  announcement naming all of the
nominees for director or specifying the size of the increased Board of Directors
made by the Company at least eighty days prior to the first  anniversary  of the
preceding  year's annual  meeting,  a  stockholder's  notice would be considered
timely,  but only with respect to nominees for any new positions created by such
increase,  if delivered to the Clerk of the Company at its  principal  executive
offices not later than the close of business on the tenth day  following the day
on which such public  announcement  was first made by the  Company.  Stockholder
proposals that do not satisfy these requirements may be rejected by the Board of
Directors.

Stockholder Vote Required to Approve Certain Transactions

     Massachusetts   law  provides   that  certain   agreements   of  merger  or
consolidation, or the sale, lease or exchange of all or substantially all of the
property  and assets,  of a  Massachusetts  corporation  must be approved by the
affirmative  vote of holders of  two-thirds of the shares of each class of stock
outstanding  and entitled to vote thereon or, if the articles of organization so
provide,  the  vote of a  lesser  proportion,  but  not  less  than a  majority.
Additionally, Massachusetts law provides that no vote of the stockholders of the
surviving  Massachusetts   corporation  is  required,  unless  its  articles  of
organization  otherwise  provide,  to approve a merger if (i) the  agreement  of
merger does not amend in any respect the corporation's articles of organization,
(ii) the number of shares of the surviving  corporation's  stock to be issued in
the merger  does not  exceed  15% of the  shares of the same  class  outstanding
immediately  prior to the effective date of the merger and (iii) the issuance of
authorized  but unissued stock pursuant to a merger by vote of the directors has
been  authorized by the by-laws or a vote of the  stockholders.  A Massachusetts
corporation owning at least 90% of the outstanding shares of each class of stock
of another  corporation may merge such corporation into itself without a vote of
the  stockholders.  The Articles provide that an affirmative vote of the holders
of a majority of the voting  power of the then  outstanding  voting stock of the
Company, voting together as a single class, may authorize any (i) sale, lease or
exchange  of all or  substantially  all of its assets or (ii)  consolidation  or
merger of the Company with or into any other  corporation  that would otherwise,
pursuant to Chapter 156B of the  Massachusetts  General  Laws,  have required an
affirmative  vote of the  holders  of  two-thirds  of the  voting  power  of the
Company's  then  outstanding  voting  stock voting  together as a single  class,
provided that, in either case, such  transaction has previously been approved by
a vote of a  majority  of the Board of  Directors  (and,  if at the time of such
action there is an Interested  Stockholder,  an additional vote of a majority of
the Continuing Directors).

     The Articles  provides  that any Business  Combination  (as defined  below)
involving  the Company  and an  Interested  Stockholder  must be approved by the
holders of at least 80% of the outstanding  shares of the Company's voting stock
voting  together  as a single  class  (the  "Voting  Requirement").  The  Voting
Requirement  does not apply and the  affirmative  vote of only a majority of the
Company's voting stock is required,  if (i) the Business Combination is approved
by an affirmative  vote of a majority of both the  Continuing  Directors and the
Board of  Directors or (ii) certain  "fair  price"  (defined  generally to mean,
among other things,  that the  consideration  to be received by  stockholders in
such  Business   Combination  shall  be  in  the  same  form  and  kind  as  the
consideration paid by the Interested Stockholder for the Company's capital stock
owned  by such  person  and  shall  be at  least  equal  to the  highest  of the
following:  (A) the highest per share price paid by such Interested  Stockholder
in  acquiring  any of its  holdings of Common  Stock  within the two year period
immediately  prior to the  first  public  announcement  of the  proposal  of the
Business  Combination (the  "Announcement  Date") or in the transaction  through
which such person became an Interested Stockholder;  (B) the highest Fair Market
Value (as defined in the  Articles) per share of Common Stock on any date during
the one-year  period prior to and including the  Announcement  Date; and (C) the
price per share equal to (1) the Fair Market  Value per share of common stock on
the Announcement Date or on the date on which the Interested  Stockholder became
an  Interested  Stockholder,  multiplied  by (2) a fraction (x) the numerator of
which is the highest per share price paid by the Interested  Stockholder for any
share of Common  Stock  acquired by it within the  two-year  period  immediately
prior to and including the Announcement Date and (y) the denominator of which is
the Fair  Market  Value  per  share of  Common  Stock on the  first  day in such
two-year  period on which the  Interested  Stockholder  acquired  any  shares of
Common  Stock)  and other  criteria  are met.  As  defined  in the  Articles,  a
"Business  Combination"   includes,   among  other  things  (i)  any  merger  or
consolidation  of the  Company  with  an  Interested  Stockholder  or  affiliate
thereof, (ii) the sale, lease, exchange, mortgage,

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pledge,  transfer or other  disposition  by the Company of assets  having a fair
market value of $1,000,000 or more to or with an  Interested  Stockholder  or an
affiliate thereof, (iii) the purchase,  exchange,  lease or other acquisition by
the Company of all or substantially all the assets or business of any Interested
Stockholder or affiliate  thereof,  (iv) the issuance or transfer by the Company
of any  securities of the Company to an Interested  Stockholder or any affiliate
thereof in exchange for cash,  securities  or other  property (or a  combination
thereof) having a fair market value of $1,000,000 or more, (v) the adoption of a
plan or proposal for the  liquidation or dissolution of the Company  proposed by
or on behalf of an Interested  Stockholder or an affiliate  thereof and (vi) any
transaction  that has the effect of increasing  the  proportionate  share of any
class  of  equity  security  of the  Company  that is  beneficially  owned by an
Interested Stockholder or any affiliate thereof.

Beneficial Ownership Limitation

     The  Articles  contain  a  prohibition   against  any  person  directly  or
indirectly offering to acquire, or acquiring,  beneficial  ownership (as defined
in the Articles) of more than 4.9% of any class of outstanding equity securities
of the Company prior to February 7, 1998, or directly or indirectly  offering to
acquire,  or  acquiring,  beneficial  ownership of more than 10% of any class of
outstanding equity securities of the Company at any time from and after February
7, 1998. The Articles contain an exception from this limitation for any offer to
the  Company  made by the  underwriters  acting  on  behalf  of the  Company  in
connection  with a public  offering  by the  Company of its  capital  stock.  In
addition,  the Articles  provide an exception for any  acquisition  of shares of
capital  stock which has been approved by an  affirmative  vote of not less than
two-thirds  of the  Board  of  Directors  then in  office  (or,  if  there is an
Interested  Shareholder at the time of such vote, then also the affirmative vote
of not less than  two-thirds of the  Continuing  Directors  then in office).  In
approving the Plan of  Reorganization,  the Massachusetts  Commissioner of Banks
has also imposed a substantially similar prohibition on any offer to acquire, or
acquisition  of, more than 10% of any class of the Company's  equity  securities
without prior notice to the Company and prior  approval of the  Commissioner  of
Banks. This regulatory limitation, which may not be waived by the Company or its
Board of Directors, remains in effect until February 7, 1998.

Amendment of Articles

     The Articles provide that an amendment must first be approved by a majority
of the Directors of the Company then in office and  thereafter by an affirmative
vote  of at  least  eighty  percent  (80%)  of the  voting  power  of  the  then
outstanding  voting stock of the Company (except that certain  provisions may be
amended by a majority vote of the  stockholders).  In addition,  if, at any time
within a sixty-day  period  prior to the meeting of  stockholders  at which such
amendment is to be considered there is an Interested Stockholder,  the amendment
must also be approved  by an  affirmative  vote of a majority of the  Continuing
Directors then in office, prior to approval by the stockholders.

Amendment of By-laws

     The Articles  provide that the By-laws may be adopted or amended  either by
the Board of Directors or the  stockholders  of the Company.  Such action by the
Board of Directors shall require the affirmative  vote of at least a majority of
the  Directors  then in office  at a duly  constituted  meeting  of the Board of
Directors,  unless  at the time of such  action  there  shall  be an  Interested
Stockholder,  in which case such action shall also require the affirmative  vote
of at least a majority of the  Continuing  Directors  then in office,  at such a
meeting.  Such  action by the  stockholders  of the  Company  shall  require (i)
approval by the affirmative vote of a majority of the Board of Directors then in
office at a duly  constituted  meeting of the Board of Directors,  unless at the
time of such action there shall be an Interested Stockholder, in which case such
action  shall also  require the  affirmative  vote at such meeting of at least a
majority of the Continuing  Directors then in office,  (ii) unless waived by the
affirmative  vote of the Board of  Directors  (and,  if  applicable,  Continuing
Directors)   specified  in  the  preceding  sentence,   the  submission  by  the
stockholders of written proposals for adopting,  altering, amending, changing or
repealing  the By-laws that comply in all respects  with the  provisions  of the
By-laws  governing such  submissions and (iii) the affirmative  vote of at least
80% of the  votes  eligible  to be cast by  stockholders  at a duly  constituted
meeting of stockholders called expressly for such purpose.


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Anti-Takeover Provisions

     Chapter  110D of the  Massachusetts  General  Laws  covers  "control  share
acquisitions" affecting corporations  incorporated in Massachusetts that have at
least  200  stockholders  and  possess  certain  statutory  indicia   reflecting
additional  substantial  ties to  Massachusetts  (as  would be the case with the
Company).  Chapter  110D limits the voting  rights of shares held by persons who
have acquired 20% or more of the voting power of the target  corporation.  Under
this statute,  shares  acquired in a control share  acquisition  retain the same
voting rights as all other shares of the same class or series only to the extent
authorized  by a vote of the  majority  of all shares  entitled  to vote for the
election of directors,  excluding such acquired  shares.  A corporation  that is
otherwise  subject to Chapter  110D may  expressly  provide in its  articles  of
organization  or bylaws that the  statute  does not apply.  Chapter  110D by its
terms would apply to the  Company.  The Company has not  included  any "opt out"
provision in either the Articles or By-laws of the Company.

     Chapter  110F  of the  Massachusetts  General  Laws  provides  that  if any
acquiror buys 5% or more of a target company's  stock,  where the target company
has at least 200 stockholders and possesses certain statutory indicia reflecting
substantial  ties or nexus to  Massachusetts,  without the prior approval of the
target  company's  board of directors,  such  acquiror  generally may not, for a
period of three  years,  (i)  complete  the  acquisition  of the target  company
through a merger,  (ii) pledge or sell any assets of the target company or (iii)
engage in other  self-dealing  transactions  with the target company.  The prior
board of directors  approval  requirement does not apply if the acquiror buys at
least 90% of the target company's  outstanding stock in the transaction in which
it crosses the 5% threshold or if the acquiror,  after  crossing the  threshold,
obtains the approval of the target  company's  board of directors and two-thirds
of the  target  company's  stock  held by persons  other  than the  acquiror.  A
corporation  that would  otherwise  be covered  by  Chapter  110F may  expressly
provide in its articles of organization that the statute does not apply. Chapter
110F by its terms would apply to the  Company.  The  Articles do not contain any
such "opt out" provision.

Item 2.  Exhibits.

     The following exhibits are filed as a part of this Registration Statement:

Exhibit Number    Description

     99.1         Articles of Organization of the Registrant

     99.2         Bylaws of the Registrant

     99.3         Annual Report on F.D.I.C. Form F-2 of Springfield Institution 
                  for Savings (the "Bank") for the fiscal year ended 
                  December 31, 1995

     99.4         Report of Independent Accountants on the financial statements 
                  of the Bank for the year ended December 31, 1993

     99.5         Notice and Proxy Statement dated March 27, 1996 for the Annual
                  Meeting of Shareholders of the Bank

     99.6         Quarterly Report on F.D.I.C. Form F-4 of the Bank for the 
                  fiscal quarter ended March 31, 1996



                                       -6-




                                    SIGNATURE

     Pursuant to the  requirements of Section 12 of the Securities  Exchange Act
of 1934, the Registrant has caused this  registration  statement to be signed on
its behalf by the undersigned, thereunto duly authorized.

                                                 SIS BANCORP, INC.



Date: June 4, 1996                     By: /s/ F. William Marshall, Jr.
                                           -----------------------------
                                           F. William Marshall, Jr.
                                           President



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