<TABLE> <S> <C>
<PAGE>
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS FINANCIAL INFORMATION EXTRACTED FROM THE CONSOLIDATED
FINANCIAL STATEMENTS OF CONNECTICUT BANCSHARES, INC. FOR THE SIX MONTHS ENDED
JUNE 30, 2000 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
<CASH> 31,175
<INT-BEARING-DEPOSITS> 9
<FED-FUNDS-SOLD> 25,007
<TRADING-ASSETS> 0
<INVESTMENTS-HELD-FOR-SALE> 0
<INVESTMENTS-CARRYING> 295,504
<INVESTMENTS-MARKET> 311,939
<LOANS> 995,239
<ALLOWANCE> 11,158
<TOTAL-ASSETS> 1,388,227
<DEPOSITS> 918,751
<SHORT-TERM> 114,778
<LIABILITIES-OTHER> 9,571
<LONG-TERM> 114,000
0
0
<COMMON> 112
<OTHER-SE> 220,883
<TOTAL-LIABILITIES-AND-EQUITY> 1,388,227
<INTEREST-LOAN> 36,734
<INTEREST-INVEST> 8,733
<INTEREST-OTHER> 0
<INTEREST-TOTAL> 45,467
<INTEREST-DEPOSIT> 18,212
<INTEREST-EXPENSE> 21,180
<INTEREST-INCOME-NET> 24,287
<LOAN-LOSSES> 450
<SECURITIES-GAINS> (1,784)
<EXPENSE-OTHER> 28,466
<INCOME-PRETAX> (1,687)
<INCOME-PRE-EXTRAORDINARY> (1,687)
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> (1,134)
<EPS-BASIC> 0.31
<EPS-DILUTED> 0.31
<YIELD-ACTUAL> 7.15
<LOANS-NON> 8,008
<LOANS-PAST> 646
<LOANS-TROUBLED> 0
<LOANS-PROBLEM> 0
<ALLOWANCE-OPEN> 10,617
<CHARGE-OFFS> 110
<RECOVERIES> 201
<ALLOWANCE-CLOSE> 11,158
<ALLOWANCE-DOMESTIC> 11,158
<ALLOWANCE-FOREIGN> 0
<ALLOWANCE-UNALLOCATED> 11,158
</TABLE>