<TABLE> <S> <C>


<ARTICLE>                                            9
<LEGEND>
This  schedule  contains  summary  financial   information  extracted  from  the
unaudited financial statements of SIS Bancorp, Inc. at and for the periods ended
June 30, 1996,  September 30, 1996,  March 31, 1997, June 30, 1997 and September
30,  1997 and is  qualified  in its  entirety  by  reference  to such  financial
statements.
</LEGEND>
<RESTATED> 
       
<S>                                <C>                    <C>                <C>                <C>                  <C>        
<PERIOD-TYPE>                       6-MOS                  9-MOS              3-MOS              6-MOS                9-MOS       
<FISCAL-YEAR-END>                     DEC-31-1996            DEC-31-1996        DEC-31-1997        DEC-31-1997          DEC-31-1997
<PERIOD-START>                        JAN-01-1996            JAN-01-1996        JAN-01-1997        JAN-01-1997          JAN-01-1997
<PERIOD-END>                          JUN-30-1996            SEP-30-1996        MAR-31-1997        JUN-30-1997          SEP-30-1997
<CASH>                                43,533                 44,469             52,612             54,058               45,023
<INT-BEARING-DEPOSITS>                309                    7,045              45                 45                   0
<FED-FUNDS-SOLD>                      11,500                 14,896             18,000             5,000                7,700
<TRADING-ASSETS>                      404                    415                468                549                  562
<INVESTMENTS-HELD-FOR-SALE>           377,526                424,162            534,460            550,264              560,207
<INVESTMENTS-CARRYING>                223,748                223,950            216,463            211,735              207,237
<INVESTMENTS-MARKET>                  222,838                223,374            213,409            210,983              209,096
<LOANS>                               738,628                756,665            782,480            818,659              849,391
<ALLOWANCE>                           18,918                 19,281             20,337             20,434               22,484
<TOTAL-ASSETS>                        1,446,147              1,527,790          1,655,648          1,695,249            1,725,081
<DEPOSITS>                            1,121,260              1,157,507          1,214,595          1,231,296            1,251,684
<SHORT-TERM>                          190,893                221,333            284,504            301,792              303,715
<LIABILITIES-OTHER>                   28,313                 32,646             35,424             38,255               41,365
<LONG-TERM>                           3,026                  3,026              2,848              2,670                2,670
<PREFERRED-MANDATORY>                 0                      0                  0                  0                    0
<PREFERRED>                           0                      0                  0                  0                    0
<COMMON>                              71                     71                 71                 71                   71
<OTHER-SE>                            102,584                113,207            118,206            121,165              125,576
<TOTAL-LIABILITIES-AND-EQUITY>        1,446,147              1,527,790          1,655,648          1,695,249            1,725,081
<INTEREST-LOAN>                       29,760                 45,419             16,249             32,942               50,368
<INTEREST-INVEST>                     17,662                 27,982             12,279             25,155               37,591
<INTEREST-OTHER>                      307                    484                295                429                  805
<INTEREST-TOTAL>                      47,729                 73,889             28,826             58,531               88,772
<INTEREST-DEPOSIT>                    19,133                 29,018             10,056             20,350               30,969
<INTEREST-EXPENSE>                    22,918                 35,443             13,912             28,554               43,769
<INTEREST-INCOME-NET>                 24,811                 38,446             14,914             29,977               45,003
<LOAN-LOSSES>                         1,847                  2,751              500                965                  1,431
<SECURITIES-GAINS>                    4                      74                 (11)               79                   120
<EXPENSE-OTHER>                       22,904                 34,922             12,435             24,742               37,366
<INCOME-PRETAX>                       7,018                  11,514             5,371              11,535               17,692
<INCOME-PRE-EXTRAORDINARY>            6,528                  17,445             3,280              6,995                10,825
<EXTRAORDINARY>                       0                      0                  0                  0                    0
<CHANGES>                             0                      0                  0                  0                    0
<NET-INCOME>                          6,528                  17,445             3,280              6,995                10,825
<EPS-PRIMARY>                         1.00                   2.66               0.50               1.06                 1.65
<EPS-DILUTED>                         0.97                   2.57               0.48               1.01                 1.56
<YIELD-ACTUAL>                        7.54                   7.58               7.61               7.61                 7.60
<LOANS-NON>                           11,228                 6,958              6,055              7,040                6,112
<LOANS-PAST>                          299                    1,183              1,315              726                  129
<LOANS-TROUBLED>                      1,588                  1,582              889                1,167                1,163
<LOANS-PROBLEM>                       32,500                 32,500             0                  0                    27,543
<ALLOWANCE-OPEN>                      18,612                 18,612             19,549             19,549               19,549
<CHARGE-OFFS>                         3,120                  4,115              222                840                  1,768
<RECOVERIES>                          1,579                  2,033              510                760                  3,272
<ALLOWANCE-CLOSE>                     18,918                 19,281             20,337             20,434               22,484
<ALLOWANCE-DOMESTIC>                  18,918                 19,281             20,337             20,434               22,484
<ALLOWANCE-FOREIGN>                   0                      0                  0                  0                    0
<ALLOWANCE-UNALLOCATED>               0                      0                  0                  0                    0
                                                                    


</TABLE>