<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 JUNE 30, 1998 AND
THE RELATED STATEMENTS OF INCOME, CHANGES IN SHAREHOLDERS' EQUITY AND CASH FLOWS
FOR THE PERIOD ENDING JUNE 30, 1998 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-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               JUN-30-1998
<CASH>                                          25,602
<INT-BEARING-DEPOSITS>                               0
<FED-FUNDS-SOLD>                                27,675
<TRADING-ASSETS>                                     0
<INVESTMENTS-HELD-FOR-SALE>                     60,223
<INVESTMENTS-CARRYING>                         107,972
<INVESTMENTS-MARKET>                           108,234
<LOANS>                                        292,846
<ALLOWANCE>                                      4,413
<TOTAL-ASSETS>                                 465,615
<DEPOSITS>                                     405,972
<SHORT-TERM>                                         0
<LIABILITIES-OTHER>                             16,296
<LONG-TERM>                                          0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         8,143
<OTHER-SE>                                      35,204
<TOTAL-LIABILITIES-AND-EQUITY>                 465,615
<INTEREST-LOAN>                                 13,653
<INTEREST-INVEST>                                3,298
<INTEREST-OTHER>                                   989
<INTEREST-TOTAL>                                17,940
<INTEREST-DEPOSIT>                               6,230
<INTEREST-EXPENSE>                               6,537
<INTEREST-INCOME-NET>                           11,403
<LOAN-LOSSES>                                      408
<SECURITIES-GAINS>                                   0
<EXPENSE-OTHER>                                  6,941
<INCOME-PRETAX>                                  5,880
<INCOME-PRE-EXTRAORDINARY>                       3,867
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     3,867
<EPS-PRIMARY>                                      .59
<EPS-DILUTED>                                      .56
<YIELD-ACTUAL>                                    5.38
<LOANS-NON>                                      6,830
<LOANS-PAST>                                         0
<LOANS-TROUBLED>                                     0
<LOANS-PROBLEM>                                 11,737
<ALLOWANCE-OPEN>                                 4,065
<CHARGE-OFFS>                                      115
<RECOVERIES>                                        55
<ALLOWANCE-CLOSE>                                4,413
<ALLOWANCE-DOMESTIC>                             4,413
<ALLOWANCE-FOREIGN>                                  0
<ALLOWANCE-UNALLOCATED>                              0
        

</TABLE>