<TABLE> <S> <C>

<PAGE>
<ARTICLE> 9
<LEGEND>
This schedule contains financial information extracted from the consolidated
financial statements of Connecticut Bancshares, Inc. for the three months ended
March 31, 2000 and is qualified in its entirety by reference to such financial
statements.
</LEGEND>
<MULTIPLIER> 1,000

<S>                             <C>
<PERIOD-TYPE>                    3-MOS
<FISCAL-YEAR-END>                          DEC-31-2000
<PERIOD-START>                             JAN-01-2000
<PERIOD-END>                               MAR-31-2000
<CASH>                                          28,670
<INT-BEARING-DEPOSITS>                             320
<FED-FUNDS-SOLD>                               130,000
<TRADING-ASSETS>                                     0
<INVESTMENTS-HELD-FOR-SALE>                          0
<INVESTMENTS-CARRYING>                         159,732
<INVESTMENTS-MARKET>                           179,791
<LOANS>                                        978,152
<ALLOWANCE>                                     10,947
<TOTAL-ASSETS>                               1,340,106
<DEPOSITS>                                     905,679
<SHORT-TERM>                                   116,308
<LIABILITIES-OTHER>                              7,590
<LONG-TERM>                                     84,000
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           112
<OTHER-SE>                                     219,896
<TOTAL-LIABILITIES-AND-EQUITY>               1,340,106
<INTEREST-LOAN>                                 17,961
<INTEREST-INVEST>                                3,784
<INTEREST-OTHER>                                     0
<INTEREST-TOTAL>                                21,745
<INTEREST-DEPOSIT>                               9,039
<INTEREST-EXPENSE>                              10,351
<INTEREST-INCOME-NET>                           11,394
<LOAN-LOSSES>                                      225
<SECURITIES-GAINS>                              (1,755)
<EXPENSE-OTHER>                                 18,206
<INCOME-PRETAX>                                 (6,520)
<INCOME-PRE-EXTRAORDINARY>                      (6,520)
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    (4,368)
<EPS-BASIC>                                          0
<EPS-DILUTED>                                        0
<YIELD-ACTUAL>                                    7.01
<LOANS-NON>                                      9,956
<LOANS-PAST>                                       383
<LOANS-TROUBLED>                                     0
<LOANS-PROBLEM>                                      0
<ALLOWANCE-OPEN>                                10,617
<CHARGE-OFFS>                                       65
<RECOVERIES>                                       170
<ALLOWANCE-CLOSE>                               10,947
<ALLOWANCE-DOMESTIC>                            10,947
<ALLOWANCE-FOREIGN>                                  0
<ALLOWANCE-UNALLOCATED>                         10,947


</TABLE>