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                                                                     EXHIBIT 4.6

                                TRUST AGREEMENT

         THIS TRUST AGREEMENT (the "Trust Agreement") is entered into as of
December 10, 2001, by and among (i) F.N.B. Corporation, a Florida corporation,
as depositor (the Depositor"); (ii) Wilmington Trust Company, a Delaware banking
corporation, as trustee; and (iii) Gary L. Tice and John D. Waters, each an
individual, as trustees (each of such trustees in (ii) and (iii) a "Trustee" and
collectively, the "Trustees"). The Depositor and the Trustees hereby agree as
follows:

         1.       The trust created hereby (the "Trust") shall be known as "FNB
Capital Trust I," in which name the Trustees, or the Depositor to the extent
provided herein, may engage in the transactions contemplated hereby, make and
execute contracts, and sue and be sued.

         2.       The Depositor hereby assigns, transfers, conveys and sets over
to the Trustees the sum of Ten Dollars ($10.00). The Trustees hereby acknowledge
receipt of such amount in trust from the Depositor, which amount shall
constitute the initial trust estate. The Trustees hereby declare that they will
hold the trust estate in trust for the Depositor. It is the intention of the
parties hereto that the Trust created hereby constitute a business trust under
Chapter 38 of Title 12 of the Delaware Code, 12 Del. C. Section 3801, et seq.
(the "Business Trust Act"), and that this document constitute the governing
instrument of the Trust. The Trustees are hereby authorized and directed to
execute and file a certificate of trust in such form as the Trustees may approve
with the Delaware Secretary of State in accordance with the provisions of the
Business Trust Act.

         3.       The Depositor and the Trustees will enter into an Amended and
Restated Trust Agreement, satisfactory to each such party and substantially in
the form included as an exhibit to the 1933 Act Registration Statement (as
defined below), to provide for the contemplated operation of the Trust created
hereby and the issuance of the Preferred Securities and Common Securities
referred to therein. Prior to the execution and delivery of such Amended and
Restated Trust Agreement, the Trustees shall not have any duty or obligation
hereunder or with respect to the trust estate, except as otherwise required by
applicable law or as may be necessary to obtain prior to such execution and
delivery of any licenses, consents or approvals required by applicable law or
otherwise. Notwithstanding the foregoing, the Trustees may take all actions
deemed proper and necessary to effect the transactions contemplated herein.

         4.       The Depositor is hereby authorized, as the agent of the Trust
and in its sole discretion, (i) to file with the Securities and Exchange
Commission (the "Commission") and execute, in each case on behalf of the Trust,
(a) the Registration Statement on Form S-3 (the "1933 Act Registration
Statement") (including any pre-effective or post-effective amendments to the
1933 Act Registration Statement) relating to the registration under the
Securities Act of 1933, as amended, of the Preferred Securities of the Trust and
certain other securities; (b) any preliminary prospectus or prospectus or
supplement thereto relating to the Preferred Securities or any such other
securities required to be filed pursuant to Rule 424 under the 1933 Act; and (c)
a Registration Statement on Form 8-A (the "1934 Act Registration Statement")
(including all pre-
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effective and post-effective amendments thereto) relating to the registration of
the Preferred Securities of the Trust under the Securities Exchange Act of 1934,
as amended; (ii) to file with the New York Stock Exchange or any other exchange
or automated quotation system (each, an "Exchange") and execute on behalf of the
Trust one or more listing applications and all other applications, statements,
certificates, agreements and other instruments as shall be necessary or
desirable to cause the Preferred Securities to be listed on any of the
Exchanges; (iii) to file and execute on behalf of the Trust such applications,
reports, surety bonds, irrevocable consents, appointments of attorney for
service of process and other papers and documents as shall be necessary or
desirable to register the Preferred Securities under the securities or blue sky
laws of such jurisdictions as the Depositor, on behalf of the Trust, may deem
necessary or desirable; (iv) to negotiate and execute on behalf of the Trust one
or more underwriting agreements relating to the Preferred Securities, among the
Trust, the Depositor and the underwriter(s) named therein, substantially in the
form included as an exhibit to the 1933 Act Registration Statement; and (v) to
apply for and obtain a tax identification number for the Trust. In the event
that any filing referred to in clauses (i), (ii) and (iii) above is required by
the rules and regulations of the Commission, an Exchange or state securities or
blue sky laws, to be executed on behalf of the Trust by one or more of the
Trustees, each of the Trustees, in its or his capacity as a Trustee of the
Trust, is hereby authorized and, to the extent so required, directed to join in
any such filing and to execute on behalf of the Trust any and all of the
foregoing, it being understood that Wilmington Trust Company in its capacity as
a Trustee of the Trust shall not be required to join in any such filing or
execute on behalf of the Trust any such document unless required by the rules
and regulations of the Commission, the Exchange or state securities or blue sky
laws. In connection with the filings referred to above, the Depositor hereby
constitutes and appoints Gary L. Tice and John D. Waters, and each of them, as
its true and lawful attorneys-in-fact and agents, with full power of
substitution and resubstitution, for the Depositor or in the Depositor's name,
place and stead, in any and all capacities, to sign any and all amendments
(including post-effective amendments) to the 1933 Act Registration Statement and
the 1934 Act Registration Statement and to file the same, with all exhibits
thereto, and other documents in connection therewith, with the Commission, the
Exchange and administrators of the state securities or blue sky laws, granting
unto said attorneys-in-fact and agents full power and authority to do and
perform each and every act and thing requisite and necessary to be done in
connection therewith, as fully to all intents and purposes as the Depositor
might or could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents or any of them, or their respective substitute or
substitutes, shall do or cause to be done by virtue hereof.

         5.       This Trust Agreement may be executed in one or more
counterparts.

         6.       The number of Trustees initially shall be three (3), and
thereafter the number of Trustees shall be such number as shall be fixed from
time to time by a written instrument signed by the Depositor which may increase
or decrease the number of Trustees; provided, however, that to the extent
required by the Business Trust Act, one Trustee shall either be a natural person
who is a resident of the State of Delaware or, if not a natural person, an
entity which has its principal place of business in the State of Delaware and
otherwise meets the requirements of applicable Delaware law. Subject to the
foregoing, the Depositor is entitled to appoint or remove without cause any
Trustee at any time. The Trustees may resign upon thirty (30) days' prior notice
to the Depositor.

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         7.       This Trust Agreement shall be governed by, and construed in
accordance with, the laws of the State of Delaware (without regard to conflict
of laws of principles).

         8.       (a)      The Trustees and their officers, directors, agents
and servants (collectively, the "Fiduciary Indemnified Persons") shall not be
liable, responsible or accountable in damages or otherwise to the Trust, the
Depositor, the Trustees or any holder of the Preferred Securities (the Trust,
the Depositor and any holder of the Trust Securities being a "Covered Person")
for any loss, damage or claim incurred by reason of any act or omission
performed or omitted by the Fiduciary Indemnified Persons in good faith on
behalf of the Trust and in a manner the Fiduciary Indemnified Persons reasonably
believed to be within the scope of authority conferred on the Fiduciary
Indemnified Persons by this Trust Agreement or by law, except that the Fiduciary
Indemnified Persons shall be liable for any such loss, damage or claim incurred
by reason of the Fiduciary Indemnified Person's negligence or willful misconduct
with respect to such acts or omissions.

                  (b)      The Fiduciary Indemnified Persons shall be fully
protected in relying in good faith upon the records of the Trust and upon such
information, opinions, reports or statements presented to the Trust by any
person as to matters the Fiduciary Indemnified Persons reasonably believes are
within such other person's professional or expert competence and who has been
selected with reasonable care by or on behalf of the Trust, including
information, opinions, reports or statements as to the value and amount of the
assets, liabilities, profits, losses, or any other facts pertinent to the
existence and amount of assets from which distributions to holders of Preferred
Securities or other securities of the trust might properly be paid.

                  (c)      The Depositor agrees, to the fullest extent permitted
by applicable law, (i) to indemnify and hold harmless each Fiduciary Indemnified
Person from and against any loss, damage, liability, tax, penalty, expense or
claim of any kind or nature whatsoever incurred by the Fiduciary Indemnified
Persons by reason of the creation, operation or termination of the Trust in a
manner the Fiduciary Indemnified Persons reasonably believed to be within the
scope of authority conferred on the Fiduciary Indemnified Persons by this Trust
Agreement of Trust, except that no Fiduciary Indemnified Persons shall be
entitled to be indemnified in respect of any loss, damage or claim incurred by
the Fiduciary Indemnified Persons by reason of negligence or willful misconduct
with respect to such acts or omissions, and (ii) to advance expenses (including
legal fees) incurred by a Fiduciary Indemnified Person in defending any claim,
demand, action, suit or proceeding, from time to time, prior to the final
disposition of such claim, demand, action, suit or proceeding, upon receipt by
the Trust of an undertaking by or on behalf of such Fiduciary Indemnified
Persons to repay such amount if it shall be determined that such Fiduciary
Indemnified Person is not entitled to be indemnified as authorized in the
preceding subsection.

                  (d)      The provisions of Section 8 shall survive the
termination of this Trust Agreement or the earlier resignation or removal of the
Fiduciary Indemnified Persons.


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         IN WITNESS WHEREOF, the parties hereto have caused this Trust Agreement
to be duly executed as of the day and year first above written.

                                             F.N.B. CORPORATION,
                                             as Depositor



                                             /s/ Gary L. Tice
                                             ---------------------------------
                                                 Gary L. Tice
                                                 President and Chief Executive
                                                 Officer


                                             WILMINGTON TRUST COMPANY,
                                             as Trustee



                                             /s/ Patricia A. Evans
                                             ---------------------------------
                                                 Patricia A. Evans
                                                 Senior Financial Services
                                                 Officer


                                             /s/ Gary L. Tice
                                             ---------------------------------
                                                 Gary L. Tice,
                                                 as Trustee


                                             /s/ John D. Waters
                                             ---------------------------------
                                                 John D. Waters,
                                                 as Trustee


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