SECOND AMENDMENT TO AGREEMENT AND PLAN OF MERGER BY AND BETWEEN TOWER BANCORP, INC. AND FNB FINANCIAL CORPORATION

Exhibit 2.1

                                SECOND AMENDMENT
                                       TO
                          AGREEMENT AND PLAN OF MERGER
                                 BY AND BETWEEN
                               TOWER BANCORP, INC.
                                       AND
                            FNB FINANCIAL CORPORATION

      WHEREAS,  Tower  Bancorp,  Inc.  ("Tower") and FNB  Financial  Corporation
("FNB") have entered into an Agreement  and Plan of Merger dated  September  21,
2005, as amended on December 14, 2005 (the "Agreement");

      WHEREAS, Tower and FNB intend that unless specifically defined herein, all
capitalized  terms in this Agreement  shall have the same meaning as the defined
terms in the Agreement;

      WHEREAS,  Tower  and FNB  mutually  agree  to  amend  and  modify  Section
7.01(b)(ii)  of the  Agreement to extend the  termination  date of the Agreement
until June 30, 2006;

      WHEREAS,  Tower  and  FNB  believe  that  this  amendment  is in the  best
interests of all parties.

      NOW,  THEREFORE,  in  consideration  of the  foregoing  and of the  mutual
agreements  and  conditions  contained  herein and for other  good and  valuable
consideration,  the receipt and  sufficiency  of which are hereby  acknowledged,
Tower and FNB, intending to be legally bound, agree as follows:

1.    Effective as of the date of this  amendment,  Section  7.01(b)(ii)  of the
      Agreement is amended and restated as follows:

      (ii)  If the Closing Date shall not have  occurred  prior to June 30, 2006
            (except  that if the  Closing  Date shall not have  occurred by such
            date because of a breach of this  Agreement by a party hereto,  such
            breaching party shall not be entitled to terminate this Agreement in
            accordance with this provision);

2.    The parties  further agree that this amendment is an amendment  within the
      meaning of Section 8.03 of the Agreement and that this amendment  complies
      with the terms and provisions thereof.

3.    Except as  provided in this  amendment,  all terms and  conditions  of the
      Agreement remain in full force and effect.

                            (Signature Page Follows)



IN WITNESS WHEREOF, the parties hereto have caused this amendment to be executed
in counterparts by their duly authorized officers and their corporate seals to
be affixed thereon this 9th day of May 2006.

ATTEST:                                 TOWER BANCORP, INC.


By: /s/ Xxxx X. XxXxxxxx, Xx.           By: /s/ Xxxxxxx X. Xxxxx
    ------------------------------          -----------------------------
    Xxxx X. XxXxxxxx, Xx.                   Xxxxxxx X. Xxxxx
    Secretary                               President & CEO


ATTEST:                                 FNB FINANCIAL CORPORATION


By: /s/ Xxxxxxxx X. Xxxxx               By: /s/ Xxxx X. Xxxxxx
    ------------------------------          -----------------------------
    Xxxxxxxx X. Xxxxx                       Xxxx X. Xxxxxx
    Secretary                               President & CEO