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                                                                    EXHIBIT 23.6

                    CONSENT OF KEEFE, BRUYETTE & WOODS, INC.

         We hereby consent to the use of our opinion letter dated June 13, 2001
to the Board of Directors of Promistar Financial Corporation, included as
Appendix C to the Joint Proxy Statement/Prospectus of ________, 2001 which forms
part of the Registration Statement dated as of the date hereof on Form S-4
relating to the proposed merger of Promistar Financial Corporation and F.N.B.
Corporation and to the references to such opinion therein.

         In giving such consent, we do not admit that we come within the
category of persons whose consent is required under Section 7 of the Securities
Act of 1933, as amended, or the rules and regulations of the Securities and
Exchange Commission thereunder, nor do we hereby admit that we are experts with
respect to any part of such Registration Statement within the meaning of the
term "experts" as used in the Securities Act of 1933, as amended, or the rules
and regulations of the Securities and Exchange Commission thereunder.



                                             /s/ KEEFE, BRUYETTE & WOODS, INC.