<TABLE> <S> <C>

<PAGE>

<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED FINANCIAL STATEMENTS OF CONNECTICUT BANKSHARES, M.H.C. AND
SUBSIDIARY AT AND FOR THE YEAR ENDED DECEMBER 31, 1999 AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               DEC-31-1999
<CASH>                                          23,661
<INT-BEARING-DEPOSITS>                              17
<FED-FUNDS-SOLD>                                 3,000
<TRADING-ASSETS>                                     0
<INVESTMENTS-HELD-FOR-SALE>                          0
<INVESTMENTS-CARRYING>                         211,862
<INVESTMENTS-MARKET>                           226,852
<LOANS>                                        948,957
<ALLOWANCE>                                     10,617
<TOTAL-ASSETS>                               1,227,798
<DEPOSITS>                                     906,591
<SHORT-TERM>                                    95,814
<LIABILITIES-OTHER>                              8,987
<LONG-TERM>                                     84,000
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                             0
<OTHER-SE>                                     123,223
<TOTAL-LIABILITIES-AND-EQUITY>               1,217,798
<INTEREST-LOAN>                                 66,425
<INTEREST-INVEST>                               12,409
<INTEREST-OTHER>                                     0
<INTEREST-TOTAL>                                78,834
<INTEREST-DEPOSIT>                              33,758
<INTEREST-EXPENSE>                              37,374
<INTEREST-INCOME-NET>                           41,460
<LOAN-LOSSES>                                    1,100
<SECURITIES-GAINS>                               1,372
<EXPENSE-OTHER>                                 36,586
<INCOME-PRETAX>                                 13,180
<INCOME-PRE-EXTRAORDINARY>                      13,180
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     8,754
<EPS-BASIC>                                          0
<EPS-DILUTED>                                        0
<YIELD-ACTUAL>                                    7.10
<LOANS-NON>                                     11,130
<LOANS-PAST>                                       355
<LOANS-TROUBLED>                                     0
<LOANS-PROBLEM>                                      0
<ALLOWANCE-OPEN>                                10,585
<CHARGE-OFFS>                                    1,360
<RECOVERIES>                                       292
<ALLOWANCE-CLOSE>                               10,617
<ALLOWANCE-DOMESTIC>                            10,617
<ALLOWANCE-FOREIGN>                                  0
<ALLOWANCE-UNALLOCATED>                         10,617


</TABLE>