<TABLE> <S> <C>

<PAGE>
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEETS OF SUMMIT BANCSHARES, INC., AS OF MARCH 31, 1998,
AND THE RELATED STATEMENTS OF INCOME, CHANGES IN SHAREHOLDERS' EQUITY AND CASH
FLOWS FOR THE PERIOD ENDING MARCH 31, 1998 AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
       
<S>                             <C>
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               MAR-31-1998
<CASH>                                          25,574
<INT-BEARING-DEPOSITS>                               0
<FED-FUNDS-SOLD>                                43,390
<TRADING-ASSETS>                                     0
<INVESTMENTS-HELD-FOR-SALE>                     59,503
<INVESTMENTS-CARRYING>                         107,449
<INVESTMENTS-MARKET>                           107,771
<LOANS>                                        287,632
<ALLOWANCE>                                      4,192
<TOTAL-ASSETS>                                 475,361
<DEPOSITS>                                     418,343
<SHORT-TERM>                                         0
<LIABILITIES-OTHER>                             14,847
<LONG-TERM>                                          0
<PREFERRED-MANDATORY>                            8,148
<PREFERRED>                                          0
<COMMON>                                             0
<OTHER-SE>                                      34,023
<TOTAL-LIABILITIES-AND-EQUITY>                 475,361
<INTEREST-LOAN>                                  6,678
<INTEREST-INVEST>                                1,637
<INTEREST-OTHER>                                   558
<INTEREST-TOTAL>                                 8,873
<INTEREST-DEPOSIT>                               3,086
<INTEREST-EXPENSE>                               3,249
<INTEREST-INCOME-NET>                            5,624
<LOAN-LOSSES>                                      158
<SECURITIES-GAINS>                                   0
<EXPENSE-OTHER>                                  3,506
<INCOME-PRETAX>                                  2,830
<INCOME-PRE-EXTRAORDINARY>                       1,864
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     1,864
<EPS-PRIMARY>                                      .29
<EPS-DILUTED>                                      .27
<YIELD-ACTUAL>                                    5.37
<LOANS-NON>                                      2,885
<LOANS-PAST>                                         0
<LOANS-TROUBLED>                                     0
<LOANS-PROBLEM>                                 12,484
<ALLOWANCE-OPEN>                                 4,065
<CHARGE-OFFS>                                       47
<RECOVERIES>                                        16
<ALLOWANCE-CLOSE>                                4,192
<ALLOWANCE-DOMESTIC>                             4,192
<ALLOWANCE-FOREIGN>                                  0
<ALLOWANCE-UNALLOCATED>                              0
        

</TABLE>