**EXHIBIT 31.2**

**CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER OF SUMMIT BANCSHARES, INC.**

| I, Bob G. Scott, certify that: |
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| 1.                             | I have reviewed this quarterly report on Form 10-Q   of Summit Bancshares, Inc.; |
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| 2.                             | Based on my knowledge, this quarterly report does   not contain any untrue statement of a material fact or omit to state a   material fact necessary to make the statements made, in light of the   circumstances under which such statements were made, not misleading with   respect to the period covered by this quarterly report; |
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| 3.                             | Based on my knowledge, the financial statements, and   other financial information included in this quarterly report, fairly present   in all material respects the financial condition, results of operations and   cash flows of the registrant as of, and for, the periods presented in this   quarterly report; |
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| 4.                             | The registrant’s other certifying officer and I are   responsible for establishing and maintaining disclosure controls and   procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and   internal control over financial reporting (as defined in Exchange Act Rules   13a-15(f) and 15d-15(f)) for the registrant and we have: |
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|                           | a) | designed such disclosure controls and procedures, or   caused such disclosure controls and procedures to be designed under our   supervision, to ensure that material information relating to the registrant,   including its consolidated subsidiaries, is made known to us by others within   those entities, particularly during the period in which this quarterly report   is being prepared; |
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|                           | b) | designed such internal control over financial   reporting, or caused such internal control over financial reporting to be   designed under our supervision, to provide reasonable assurance regarding the   reliability of financial reporting and the preparation of financial   statements for external purposes in accordance with generally accepted   accounting principles; |
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|                           | c) | evaluated the effectiveness of the registrant’s   disclosure controls and procedures and presented in this report our   conclusions about the effectiveness of the disclosure controls and   procedures, as of the end of the period covered by this report based on such   evaluation; and |
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|                           | d) | disclosed in this quarterly report any change in the   registrant’s internal control over financial reporting that occurred during   the registrant’s most recent fiscal quarter that has materially affected, or   is reasonably likely to materially affect, the registrant’s internal control   over financial reporting; and |
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| 5.                             | The registrant’s other certifying officer and I have   disclosed, based on our most recent evaluation of internal control over   financial reporting, to the registrant’s auditors and the audit committee of   the registrant’s board of directors (or persons performing the equivalent   function): |
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|                           | a) | all significant deficiencies and material weaknesses   in the design or operation of internal control over financial reporting which   are reasonably likely to adversely affect    the registrant’s ability to record, process, summarize and report   financial information; and |
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|                           | b) | any fraud, whether or not material, that involves   management or other employees who have a significant role in the registrant’s   internal control over financial reporting. |