<TABLE> <S> <C>

<PAGE>
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEETS OF SUMMIT BANCSHARES, INC., AS OF SEPTEMBER 30,
1996, AND THE RELATED STATEMENTS OF INCOME, CHANGES IN SHAREHOLDERS' EQUITY AND
CASH FLOWS FOR THE PERIOD ENDING SEPTEMBER 30, 1996 AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1996
<PERIOD-START>                             JAN-01-1996
<PERIOD-END>                               SEP-30-1996
<CASH>                                          24,962
<INT-BEARING-DEPOSITS>                               0
<FED-FUNDS-SOLD>                                 8,330
<TRADING-ASSETS>                                     0
<INVESTMENTS-HELD-FOR-SALE>                     60,069
<INVESTMENTS-CARRYING>                         123,019
<INVESTMENTS-MARKET>                           122,541
<LOANS>                                        213,962
<ALLOWANCE>                                      3,008
<TOTAL-ASSETS>                                 379,894
<DEPOSITS>                                     329,798
<SHORT-TERM>                                         0
<LIABILITIES-OTHER>                             16,753
<LONG-TERM>                                          0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         4,043
<OTHER-SE>                                      29,300
<TOTAL-LIABILITIES-AND-EQUITY>                 379,894
<INTEREST-LOAN>                                 14,051
<INTEREST-INVEST>                                5,560
<INTEREST-OTHER>                                   672
<INTEREST-TOTAL>                                20,283
<INTEREST-DEPOSIT>                               6,833
<INTEREST-EXPENSE>                               7,214
<INTEREST-INCOME-NET>                           13,069
<LOAN-LOSSES>                                      480
<SECURITIES-GAINS>                                 (15)
<EXPENSE-OTHER>                                  8,267
<INCOME-PRETAX>                                  6,567
<INCOME-PRE-EXTRAORDINARY>                       4,314
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     4,314
<EPS-PRIMARY>                                     1.35
<EPS-DILUTED>                                     1.35
<YIELD-ACTUAL>                                    5.21
<LOANS-NON>                                      1,282
<LOANS-PAST>                                         0
<LOANS-TROUBLED>                                     0
<LOANS-PROBLEM>                                  4,050
<ALLOWANCE-OPEN>                                 2,500
<CHARGE-OFFS>                                       69
<RECOVERIES>                                        97
<ALLOWANCE-CLOSE>                                3,008
<ALLOWANCE-DOMESTIC>                             3,008
<ALLOWANCE-FOREIGN>                                  0
<ALLOWANCE-UNALLOCATED>                              0
        

</TABLE>