Exhibit 15 - Letter Re: Unaudited Interim Financial Information

The Board of Directors
F.N.B. Corporation

We are aware of the  incorporation  by reference in the following  Registration
Statements and in their related  Prospectuses,  of our report  dated  October
15, 2003,  relating  to the  unaudited  consolidated  interim  financial
statements of F.N.B. Corporation and subsidiaries that are included in its
Form 10-Q for the quarter ended September 30, 2003:

1.   Registration Statement on Form S-8 relating to F.N.B. Corporation 1990
     Stock Option Plan (File #33-78114).

2.   Registration Statement on Form S-8 relating to F.N.B. Corporation
     Restricted Stock Bonus Plan (File #33-78134).

3.   Registration Statement on Form S-8 relating to F.N.B. Corporation 1996
     Stock Option Plan (File #333-03489).

4.   Registration Statement on Form S-8 relating to F.N.B. Corporation
     Restricted Stock and Incentive Bonus Plan (File #333-03493).

5.   Registration Statement on Form S-8 relating to F.N.B. Corporation
     Directors Compensation Plan (File #333-03495).

6.   Registration Statement on Form S-8 relating to F.N.B. Corporation 401(k)
     Plan (File #333-38372).

7.   Post-Effective Amendment No. 1 on Form S-8 to Registration Statement on
     Form S-4 (File #333-01997).

8.   Post-Effective Amendment No. 1 on Form S-8 to Registration Statement on
     Form S-4 (File #333-22909).

9.   Registration Statement on Form S-3 relating to F.N.B. Corporation
     Subordinated Notes and Daily Cash Accounts (File #333-74737).

10.  Registration Statement on Form S-8 relating to stock options assumed in
     the acquisition of Mercantile Bank of Southwest Florida (File #333-42333).

11.  Post-Effective Amendment No. 1 on Form S-8 to Registration Statement on
     Form S-4 (File #333-58727).

12.  Registration Statement on Form S-3 relating to stock warrants assumed in
     the acquisitions of Southwest Banks, Inc. and West Coast Bancorp, Inc.
     (File #333-31124).

13.  Post Effective Amendment No. 1 to Form S-3 relating to the F.N.B.
     Corporation Dividend Reinvestment and Direct Stock
     Purchase Plan (File #333-38374).

14.  Amendment No. 1 to Form S-3 relating to the registration of F.N.B.
     Corporation Subordinated Term Notes and Daily Notes (File #333-38370).

15.  Registration Statement on Form S-8 relating to the F.N.B. Corporation
     Salary Savings Plan (File #333-40648).

16.  Registration Statement on Form S-8 relating to the F.N.B. Corporation
     1998 Directors Stock Option Plan (File #333-38376).




17.  Registration Statement on Form S-8 relating to the F.N.B. Corporation 2001
     Incentive Plan (File #333-63042).

18.  Registration Statement on Form S-3 relating to the registration of F.N.B.
     Corporation and FNB Capital Trust I common stock, preferred stock, debt
     securities, warrants, and trust preferred securities (File #333-74866).

19.  Registration Statement on Form S-8 relating to the F.N.B. Corporation 1996
     Incentive Plan (File #333-83760).

20.  Registration Statement on Form S-8 relating to stock option agreements
     granted under the Promistar Financial Corporation 1998 Equity Incentive
     Plan and assumed by F.N.B. Corporation (File #333-83756).

21.  Registration Statement on Form S-8 relating to the F.N.B. Corporation
     401(k) Plan (File #333-97113).

22.  Registration Statement on Form S-8 relating to the Roger Bouchard
     Insurance, Inc. 401(k) Plan (File #333-97115).

23.  Registration Statement on Form S-3 relating to the F.N.B. Corporation
     Dividend Reinvestment and Direct Stock Purchase Plan (File #333-97111).

24.  Registration Statement on Form S-3 relating to the registration of F.N.B.
     Corporation subordinated notes (File #333-103902).


                                               /s/Ernst & Young LLP

Birmingham, Alabama
November 10, 2003