1
                                                                     Exhibit 2.1

                               AGREEMENT OF MERGER
                                       AND
                             PLAN OF REORGANIZATION


                                 BY AND BETWEEN


                                    UNB CORP.


                    THE UNITED NATIONAL BANK & TRUST COMPANY

                              BANCFIRST OHIO CORP.

                                       AND

                   THE FIRST NATIONAL BANK OF ZANESVILLE, N.A.



                                SEPTEMBER 5, 2001


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                                TABLE OF CONTENTS



                                                                                                               PAGE
                                                                                                               ----

                                                                                                           
Article I.        THE MERGERS.....................................................................................1
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Article II.       CORPORATE GOVERNANCE OF THE SURVIVING CORPORATION...............................................3
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Article III.      EXCHANGE OF SHARE CERTIFICATES..................................................................6
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Article IV.       REPRESENTATIONS AND WARRANTIES OF BANCFIRST AND BANCFIRST BANK..................................9
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Article V.        REPRESENTATIONS AND WARRANTIES OF UNB AND UNB BANK.............................................29
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Article VI.       COVENANTS......................................................................................47
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Article VII.      ADDITIONAL AGREEMENTS..........................................................................53
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Article VIII.     CONDITIONS PRECEDENT...........................................................................60
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Article IX.       TERMINATION AND AMENDMENT......................................................................62
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Article X.        GENERAL PROVISIONS.............................................................................64
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ANNEX A           1
- -------



                                    EXHIBITS

Exhibit 1, Option Agreements...................................................

Exhibit 2, Bank Merger Agreement...............................................

Exhibit 1.5, Articles of Incorporation and Code of Regulations of the
Surviving Corporation..........................................................

Exhibit 2.3, Executive Retention Agreements and Severance Agreements...........



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                 AGREEMENT OF MERGER AND PLAN OF REORGANIZATION

         THIS AGREEMENT OF MERGER AND PLAN OF REORGANIZATION (this "Agreement")
is made and entered into this 5th day of September, 2001, by and among UNB
Corp., an Ohio corporation ("UNB"); The United National Bank & Trust Company, a
national banking association organized under the laws of the United States of
America ("UNB Bank"); BancFirst Ohio Corp., an Ohio corporation ("BancFirst");
and The First National Bank of Zanesville, N.A., a national banking association
organized under the laws of the United States of America ("BancFirst Bank").

                                   WITNESSETH:

         WHEREAS, the Boards of Directors of UNB, UNB Bank, BancFirst and
BancFirst Bank have determined that it is in the best interests of their
respective companies and their respective shareholders to enter into certain
business combination transactions in which BancFirst will merge with and into
UNB (the "Merger"); and BancFirst Bank will merge with and into UNB Bank (the
"Bank Merger") in a merger-of-equals transaction; and

         WHEREAS, as an inducement for each to complete such process, UNB and
BancFirst are each granting to the other an option to purchase common shares on
terms and conditions specified in option agreements of even date, attached
hereto as Exhibit 1 (the "Option Agreements");

         NOW, THEREFORE, in consideration of the premises and the mutual
covenants and agreements hereinafter set forth, UNB, UNB Bank, BancFirst and
BancFirst Bank, each intending to be legally bound, hereby agree as follows:

                             ARTICLE I THE MERGERS

     1.1 The Mergers.

         (a) Subject to the terms and conditions of this Agreement, and pursuant
to the provisions of the Ohio General Corporation Law (the "OGCL") and
applicable federal laws and regulations, BancFirst shall merge with and into UNB
in accordance with the provisions of Section 1701.78 of the OGCL; and the
separate corporate existence of BancFirst shall cease at the Effective Time(1).
UNB shall be the surviving corporation of the Merger (the "Surviving
Corporation") and shall continue its corporate existence under the laws of the
State of Ohio. From and after the Effective Time, the Surviving Corporation
shall possess all assets and property of every description, and every interest
in the assets and property, wherever located, and the rights, privileges,
immunities, powers, franchises and authority, of a public as well as a private
nature, of BancFirst and all obligations belonging or due to BancFirst.

         (b) Concurrently with, or as soon as possible after, the Merger, UNB
and BancFirst shall cause the Bank Merger to be completed in accordance with the
Agreement and Plan of Merger attached hereto as Exhibit 2 (the "Bank Merger
Agreement").

- --------
(1) All capitalized terms (that are not proper nouns) not defined herein shall
have the meanings ascribed to them in attached Annex A.


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         (c) BancFirst and UNB, by action of their respective Boards of
Directors, may at any time change the method of effecting the combinations of
BancFirst and UNB and BancFirst Bank and UNB Bank (including, without
limitation, the provisions of this Article I) if and to the extent BancFirst and
UNB deem such change to be desirable; provided, however, that no such change
shall (i) alter or change the amount or composition of the Per Share Merger
Consideration, or (ii) be likely to materially delay or jeopardize receipt of
any required regulatory approvals or materially delay or prevent the
satisfaction of any conditions to the Closing.

     1.2 CONVERSION AND CANCELLATION OF BANCFIRST SHARES. At the Effective Time
and as a result of the Merger, automatically and without further act of UNB, UNB
Bank, BancFirst, BancFirst Bank or the holders of the voting common stock of
BancFirst (the "BancFirst Shares"), the following shall occur:

         (a) Each BancFirst Share issued and outstanding shall be canceled and
extinguished and, in substitution and exchange therefor, the holders thereof
shall be entitled, subject to and upon compliance with Article III of this
Agreement, to receive from UNB One and 325/1000 (1.325) shares of voting common
stock of UNB ("UNB Shares") (the "Per Share Merger Consideration").

             (i)   The Per Share Merger Consideration shall be adjusted to
                   reflect any stock split, stock dividend or distributions in,
                   or combinations or subdivisions of, UNB Shares, which is
                   paid, or for which a record date occurs, between the date
                   hereof and the Effective Time.

             (ii)  No fractional shares will be issued, and cash will be paid in
                   lieu of fractional shares based on the average of the bid and
                   asked price quotes of the UNB common shares as reported on
                   the Nasdaq National Market System ("NASDAQ") by a mutually
                   agreed upon authoritative source on the last day of trading
                   of UNB Shares prior to the Effective Time (the "UNB Market
                   Value").

         (b) Any treasury shares held by BancFirst and any BancFirst Shares
owned by UNB for its own account shall be canceled and retired at the Effective
Time, and no consideration shall be issued in exchange therefor.

     1.3 BANCFIRST OPTIONS.

         (a) At the Effective Time, each outstanding option under the 1997
Omnibus Stock Option and Incentive Plan (the "BancFirst Option Plan") shall be
converted into an option to purchase shares of the Surviving Corporation in an
amount equal to the Merger Consideration which would have been payable had the
shares which are the subject of the option been outstanding, equal to the
exercise price per BancFirst Share under the BancFirst Option Plan divided by
the Per Share Merger Consideration.

         (b) At the Effective Time, each outstanding option under the UNB Bank
1987 Stock Option Plan (the "UNB Plan I") and the UNB Bank 1997 Stock Option
Plan (the "UNB


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Plan II") shall be converted into an option to purchase shares of the Surviving
Corporation in an amount equal to one share for each share purchasable under the
option.

         1.4 CLOSING AND EFFECTIVE TIME. The closing of the Merger pursuant to
this Agreement (the "Closing") shall take place, unless another date is agreed
upon by UNB and BancFirst, thirty (30) days after the satisfaction or waiver of
the last of the conditions to the Merger set forth in Section 8.1 of this
Agreement to be satisfied. On the day of the Closing, UNB and BancFirst shall
cause a Certificate of Merger in respect of the Merger to be filed in the Office
of the Ohio Secretary of State. The Merger shall become effective at the date
and time indicated on such filing (the "Effective Time").

         1.5 ARTICLES OF INCORPORATION AND CODE OF REGULATIONS. The Articles of
Incorporation and Code of Regulations attached as Exhibit 1.5 hereto shall be
the Articles of Incorporation and Code of Regulations of the Surviving
Corporation.

         1.6 TAXES; TAX AND ACCOUNTING CONSEQUENCES. It is intended that the
Merger shall constitute a reorganization within the meaning of Section 368(a) of
the Internal Revenue Code of 1986, as amended (the "Code"), and that this
Agreement shall constitute a "plan of reorganization" for the purposes of
Sections 354 and 361 of the Code.

         1.7 NAME OF SURVIVING CORPORATION, BANK. The name of the Surviving
Corporation shall be jointly determined by the boards of directors of UNB and
BancFirst prior to October 31, 2001, and holders of BancFirst Shares and UNB
Shares shall be entitled to receive shares of voting common stock in the new
name of the Surviving Corporation pursuant to Article III hereof. The name of
the Surviving Bank shall be jointly determined by the boards of directors of UNB
and BancFirst prior to October 31, 2001.

         1.8 HEADQUARTERS OF SURVIVING CORPORATION, BANK. At the Effective Time,
the location of the headquarters and principal executive offices of the
Surviving Corporation shall be that of the headquarters and principal executive
offices of UNB as of the date of this Agreement. At the Effective Time, the
location of the headquarters and principal executive offices of the Surviving
Bank shall be that of the headquarters and principal executive offices of UNB
Bank as of the date of this Agreement.


          ARTICLE II CORPORATE GOVERNANCE OF THE SURVIVING CORPORATION

     2.1 SURVIVAL OF ARTICLE II. Notwithstanding any other provision in this
Agreement, the provisions of this Article II shall survive the Effective Time
and remain continuously in effect until December 31, 2005 (the "Termination
Date"), on which date the provisions of this Article II shall terminate. This
Section 2.1 shall not affect the term of any Change of Control Agreements
referred to in this Article II.

     2.2 BOARD OF DIRECTORS OF SURVIVING CORPORATION.

         (a) COMPOSITION. The Board of Directors will consist of fourteen (14)
members, seven (7) of whom shall be designated by BancFirst ("Former BancFirst
Directors") and seven (7) of whom shall be designated by UNB ("Former UNB
Directors"), in each case such designation to occur within 30 days of the date
hereof. BancFirst and UNB will designate


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         not less than two (2) directors each to classes one, two and three,
         respectively, of directors of the Surviving Corporation.

         (b) CERTAIN MEMBERS OF THE BOARD OF DIRECTORS. Mr. Gary N. Fields of
BancFirst will be a member of the Board of Directors and will serve as its
Chairman. The current Chairman, President and Chief Executive Officer of UNB,
Mr. Roger L. Mann, will be a member of the Board of Directors.

         (c) NOMINATION OF DIRECTORS.

             (i)   Nominees to the Board of Directors will be recommended to the
                   Board of Directors by a Nominating Committee (A) for election
                   to the Board of Directors at the shareholder meetings at
                   which directors are to be elected; and (B) to fill vacancies
                   on the Board of Directors in between such shareholder
                   meetings (a "Nominating Committee"). For any position on the
                   Board of Directors occupied, or vacated, as the case may be,
                   by a Former BancFirst Director, the Nominating Committee
                   shall consist of two Former BancFirst Directors and one
                   Former UNB Director; for any position on the Board of
                   Directors occupied, or vacated, as the case may be, by a
                   Former UNB Director, the Nominating Committee shall consist
                   of two Former UNB Directors and one Former BancFirst
                   Director. A nominee shall need a two-thirds (2/3) vote of the
                   Nominating Committee to be recommended for a position on the
                   Board of Directors. Former BancFirst Directors on the
                   Nominating Committee will be appointed at the recommendation
                   of Mr. Fields; Former UNB Directors on the Nominating
                   Committee will be appointed at the recommendation of Mr.
                   Mann; provided, that, should Mr. Fields or Mr. Mann be
                   otherwise unable to appoint such members of the Nominating
                   Committee, the Former BancFirst Directors will be appointed
                   at the recommendation of the most senior (in service) Former
                   BancFirst Director then on the Board of Directors and the
                   Former UNB Directors will be appointed at the recommendation
                   of the most senior (in service) Former UNB Director then on
                   the Board of Directors.

             (ii)  Any person filling a membership position on the Board of
                   Directors previously occupied or vacated by a Former
                   BancFirst Director and nominated in accordance with the
                   previous paragraph shall be considered a "Former BancFirst
                   Director"; any person filling a membership position on the
                   Board of Directors previously occupied or vacated by a Former
                   UNB Director and nominated in accordance with the previous
                   paragraph shall be considered a "Former UNB Director."


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         (d) SUBSIDIARIES AND COMMITTEES.

             (i)   The initial board of directors of the Surviving Bank will
                   consist of twelve (12) members, six (6) of whom shall be
                   designated by BancFirst and six (6) of whom shall be
                   designated by UNB, in each case such designation to occur
                   within thirty (30) days of the date hereof.

             (ii)  The boards of directors of Subsidiaries of the Surviving
                   Corporation and of committees of the board of directors of
                   the Surviving Corporation and its Subsidiaries shall be
                   composed equally of former BancFirst Directors and former UNB
                   Directors and, except as otherwise agreed by Messrs. Fields
                   and Mann there shall be an equal division and equitable
                   allocation of chairmanships as between the former BancFirst
                   Directors and former UNB Directors.

     2.3 OFFICERS OF THE SURVIVING CORPORATION AND THE SURVIVING BANK.

         (a) COMPOSITION. Mr. Mann shall be President and Chief Executive
Officer of the Surviving Corporation and Chairman of the Surviving Bank as of
the Effective Time. Mr. James Nicholson shall be Executive Vice President and
Chief Operating Officer of the Surviving Corporation and President and Chief
Executive Officer of the Surviving Bank as of the Effective Time. Mr. James
Pennetti shall be Executive Vice President and Chief Financial Officer of the
Surviving Corporation and the Surviving Bank as of the Effective Time. Mr. Mann,
Mr. Nicholson and Mr. Pennetti shall serve in the positions described in this
Section 2.3(a) until the Termination Date or until otherwise determined in
accordance with Section 2.4.

         (b) CHANGE OF CONTROL AGREEMENTS. The Surviving Corporation will assume
all obligations of BancFirst and BancFirst Bank and UNB and UNB Bank under those
certain Executive Retention Agreements and Severance Agreements executed by
certain members of management of each organization which are identified on
Exhibit 2.3 (each of these agreements, or any successor agreement, a "Change of
Control Agreement"). During the terms of their respective Change of Control
Agreements, such persons shall have the respective powers, and perform the
respective duties, set forth in each of their respective Change of Control
Agreements, along with the duties of their offices as described in this Article
II and the Articles of Incorporation or Code of Regulations of the Surviving
Corporation. The Change of Control Agreements of Messrs. Mann and Pennetti shall
be amended to waive their right to severance and termination benefits should
they voluntarily terminate their employment with the Surviving Corporation six
(6) months following the Effective Date of the merger of BancFirst and UNB
without "Good Reason" as that term is defined in Article III of their respective
Severance Agreements dated May 8, 2001. All other terms and provisions of said
Severance Agreements, including Mr. Mann's and Mr. Pennetti's right to
voluntarily terminate their employment for any reason after six (6) months upon
a Change of Control, as that term is defined in their Severance Agreements dated
May 8, 2001, other than the merger of BancFirst and UNB, as described in this
Agreement of Merger and Plan of Reorganization, shall remain in full force and
effect and be binding upon Messrs. Mann, Pennetti and the Surviving Corporation.


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     2.4 MODIFICATIONS TO CORPORATE GOVERNANCE PROVISIONS.

         (a) A "Special Majority" shall mean three-fourths (3/4) of the
directors of the Surviving Corporation. The Articles of Incorporation or Code of
Regulations of the Surviving Corporation will provide that, until the
Termination Date, the following actions will require the approval of a Special
Majority:

             (i)   The removal of Mr. Mann, Mr. Fields, Mr. Nicholson, or Mr.
                   Pennetti from any of such person's executive positions with
                   the Surviving Corporation, including by modification of the
                   succession arrangements described above;

             (ii)  Any change in the size of the Board of Directors or number of
                   directors to be Former BancFirst Directors or the number of
                   directors to be Former UNB Directors; and

             (iii) Any change or amendment to the Articles of Incorporation or
                   Code of Regulations relating to or affecting the arrangements
                   discussed in this Article II or Exhibit 2.2.

         (b) The Articles of Incorporation or Code of Regulations of the
Surviving Corporation shall also provide that any officer or other person acting
on behalf of the Surviving Corporation in its capacity as sole shareholder of
the Surviving Bank may not make any changes or amendment to the Governing
Documents of any subsidiary of the Surviving Corporation relating to or altering
those provisions mirroring the provisions discussed in this Article II, without
the vote of a Special Majority.

      2.5 ARTICLES OF INCORPORATION AND CODE OF REGULATIONS. As contemplated
by Section 2.2, the Articles of Incorporation and Code of Regulations will
contain appropriate provisions giving effect to Sections 2.1 through 2.4.

                   ARTICLE III. EXCHANGE OF SHARE CERTIFICATES

     3.1 SHARE CERTIFICATES IN THE MERGER.

         (a) As soon as practicable after the Effective Time, the Surviving
Corporation shall mail to each holder of record of BancFirst Shares (and UNB
Shares, should the name of the Surviving Corporation be other than UNB), a form
letter of transmittal (the "Transmittal Letter") including instructions for use
in effecting the surrender for exchange of the certificates formerly evidencing
the BancFirst Shares canceled and extinguished as a result of the Merger and UNB
shares affected by the change in name of the Surviving Corporation
(collectively, the "Certificates" and individually, the "Certificate"). The
Transmittal Letter shall specify that the risk of loss and title to Certificates
shall pass only upon delivery of the Certificates as specified in the
Transmittal Letter. Upon surrender of a Certificate for cancellation
representing shares of BancFirst, together with such Transmittal Letter, duly
executed, the holder of such Certificate shall be entitled to receive in
exchange therefor the Per Share Merger Consideration, and the Certificate so
surrendered shall thereafter be canceled forthwith. Upon surrender of a
certificate representing shares of UNB, together with such Transmittal Letter,
duly executed, the holder of



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such certificate shall be entitled to receive in exchange therefore a
certificate representing the same number of shares in the new name of the
Surviving Corporation. UNB may, at its election, designate an exchange agent to
discharge its duties pursuant to this Section 3.1.

         (b) In the event that any holder of BancFirst Shares is unable to
deliver the Certificate, the Surviving Corporation, in the absence of actual
notice that any BancFirst Shares theretofore represented by any such Certificate
have been acquired by a bona fide purchaser, shall deliver to such holder the
Per Share Merger Consideration to which such holder is entitled in accordance
with the provisions of this Agreement upon the presentation of all of the
following:

             (i)   Evidence to the reasonable satisfaction of the Surviving
                   Corporation that any such Certificate has been lost,
                   wrongfully taken or destroyed;

             (ii)  Such security or indemnity as may be reasonably requested by
                   the Surviving Corporation to indemnify and hold the Surviving
                   Corporation and the exchange agent harmless; and

             (iii) Evidence to the reasonable satisfaction of the Surviving
                   Corporation that such person is the owner of the BancFirst
                   Shares theretofore represented by each Certificate claimed by
                   him to be lost, wrongfully taken or destroyed and that he is
                   the person who would be entitled to present each such
                   Certificate for exchange pursuant to this Agreement.

         (c) In the event that delivery of the Per Share Merger Consideration
provided for herein is to be made to a person other than the person in whose
name the Certificate surrendered is registered, the Certificate so surrendered
shall be properly endorsed or otherwise in proper form for transfer; and the
person requesting such issuance or payment shall pay any transfer or other taxes
required by reason of the issuance or payment to a person other than the
registered holder of the Certificate surrendered or establish to the
satisfaction of the Surviving Corporation that such tax has been paid or is not
applicable. Until surrendered in accordance with the provisions of this Section
3.1, each Certificate representing ownership of BancFirst Shares shall represent
for all purposes only the right to receive the Per Share Merger Consideration.

         (d) No dividends or other distributions declared after the Effective
Time with respect to the Surviving Corporation Shares and payable to the holders
of record thereof after the Effective Time shall be paid to the holder of any
unsurrendered Certificate until the holder thereof shall surrender such
Certificate. After the subsequent surrender and exchange of a Certificate, the
record holder thereof shall be entitled to receive any such dividends or other
distributions, without any interest thereon, which theretofore had become
payable with respect to the Surviving Corporation Shares represented by such
Certificate.


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         (e) No consideration provided for herein shall be delivered by the
Surviving Corporation to any former holder of BancFirst Shares in accordance
with this Agreement until such holder shall have complied with this Section 3.1.

         (f) If outstanding Certificates are not surrendered or the payment for
them is not claimed prior to the date on which such payment would otherwise
escheat to or become the property of any governmental entity, the unclaimed
items shall, to the extent permitted by abandoned property and any other
applicable law, become the property of the Surviving Corporation (and to the
extent not in its possession shall be delivered to it), free and clear of all
claims or interest of any person previously entitled to such property. Neither
the exchange agent nor any party to this Agreement shall be liable to any holder
of any Certificate for any consideration paid to a public official pursuant to
applicable abandoned property, escheat or similar laws. The Surviving
Corporation and the exchange agent shall be entitled to rely upon the stock
transfer books of BancFirst to establish the identity of those persons entitled
to receive the Per Share Merger Consideration, which books shall be conclusive
with respect thereto. In the event of a dispute with respect to ownership of
BancFirst Shares, the Surviving Corporation and the exchange agent shall be
entitled to deposit any Per Share Merger Consideration represented thereby in
escrow with an independent third party and thereafter be relieved with respect
to any claims thereto.

     3.2 PAYMENT IN SATISFACTION OF RIGHTS. All payments made upon the surrender
of Certificates pursuant to this Article III shall be deemed to have been made
in full satisfaction of all rights pertaining to the BancFirst Shares or UNB
Shares, as the case may be, theretofore evidenced by such Certificates.

     3.3 NO FURTHER REGISTRATION OR TRANSFER. After the Effective Time, there
shall be no further registration or transfer of BancFirst Shares on the stock
transfer books of BancFirst. In the event that, after the Effective Time,
Certificates evidencing such BancFirst Shares are presented for transfer, they
shall be canceled and exchanged as provided in this Article III.

     3.4 DISSENTING BANCFIRST SHARES.

         (a) Any holder of BancFirst or UNB Shares who seeks relief as a
dissenting shareholder under Section 1701.85 of the OGCL (a "Dissenting
Shareholder") shall be entitled to payment for such BancFirst Shares and UNB
Shares only to the extent permitted by and in accordance with the provisions of
the OGCL; provided, however, that if, in accordance with the OGCL, any
Dissenting Shareholder shall forfeit such right to payment of the fair value of
the BancFirst Shares or UNB Shares held by such Dissenting Shareholder, such
BancFirst Shares or UNB Shares shall thereupon be deemed to have been converted
into and to have become exchangeable for, as of the Effective Time, the right to
receive the Per Share Merger Consideration. Dissenting Shareholders shall not,
after the Effective Time, be entitled to vote for any purpose or receive any
dividends or other distributions and shall be entitled only to such rights as
are afforded pursuant to the OGCL.


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         (b) BancFirst and UNB shall give each other:

             (i)   Prompt notice of any written objections to the Merger and any
                   written demands for the payment of the fair value of any
                   shares, withdrawals of such demands, and any other
                   instruments served pursuant to the OGCL received by either;
                   and

             (ii)  The opportunity to participate in all negotiations and
                   proceedings with respect to such demands under the OGCL.

         (c) BancFirst and UNB shall not voluntarily make any payment with
respect to any demands for payment of fair value and shall not settle or offer
to settle any such demands, except with the prior written consent of the other.

   ARTICLE IV. REPRESENTATIONS AND WARRANTIES OF BANCFIRST AND BANCFIRST BANK

    BancFirst and the BancFirst Bank represent and warrant to UNB that each
of the following statements is true and accurate in all material respects,
except as otherwise disclosed in a schedule provided by BancFirst and the
BancFirst Bank to UNB prior to the execution of this Agreement (the "BancFirst
Disclosure Schedule"). The BancFirst Disclosure Schedule shall be arranged in
paragraphs corresponding to the lettered Sections and Subsections contained in
this Article IV, and the disclosure in any letter paragraph shall qualify only
the corresponding Section or Subsection in this Article IV.

    4.1 ORGANIZATION AND STANDING.

         (a) BancFirst is a corporation duly organized, validly existing and in
good standing under the laws of the State of Ohio and has the corporate power
and authority to own or hold under lease all of its properties and assets and to
conduct its business and operations as presently conducted. BancFirst is
registered as a bank holding company under the Bank Holding Company Act of 1956,
as amended (the "BHCA"). BancFirst has filed an election to become, and
presently is, a "financial holding company" under 12 C.F.R. Section 225.82, has
not received any notice from the Federal Reserve Board pursuant to 12 C.F.R.
Section 225.82(e)(1), continues to satisfy all requirements for financial
holding company status under 12 C.F.R. Section 225.81, and is not subject to any
limitation under 12 C.F.R. Sections 225.83 or 225.84. BancFirst is in compliance
in all material respects with all applicable local, state or federal laws and
regulations.

         (b) BancFirst Bank is a national banking association duly organized and
validly existing under the National Bank Act, as amended (the "NBA") and has the
corporate power and authority to own or hold under lease all of its properties
and assets and to conduct its business and operations as presently conducted.
The deposit accounts of BancFirst Bank are insured up to applicable limits by
the Bank Insurance Fund of the FDIC (the "BIF") or the Savings Association
Insurance Fund of the FDIC, and BancFirst Bank has paid all deposit insurance
premiums and assessments required by applicable law. BancFirst Bank is in
compliance in all material respects with all applicable local, state or federal
laws and regulations, including without limitation, the Equal Credit Opportunity
Act, the Fair Housing Act, the


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Community Reinvestment Act, the Home Mortgage Disclosure Act and all other
applicable fair lending laws and other laws relating to discriminatory business
practices.

    4.2 SUBSIDIARIES.

         (a) First Financial Services Group, N.A., is a limited purpose trust
bank duly organized and validly existing under the NBA (the "Trust Company").
Chornyak & Associates, Inc., is a corporation duly organized and validly
existing under the laws of the State of Ohio ("Chornyak"). Bankers Title
Services, Inc., is a corporation duly organized and validly existing under the
laws of the State of Ohio ("Title Agency"). BFOH Capital Trust I ("Capital
Trust") is a statutory business trust duly organized and validly existing under
the laws of the State of Delaware. The Trust Company, Chornyak, the Title Agency
and Capital Trust are collectively referred to hereafter as the "BancFirst
Subsidiaries". Additional subsidiaries of BancFirst are listed in Section 4.2(a)
of the BancFirst Disclosure Schedule.


         (b) Each BancFirst Subsidiary has the full corporate power, right,
authority and governmental authorizations to own or lease its properties and
assets and to carry on its business as it now is being conducted in all material
respects. Each BancFirst Subsidiary is in compliance in all material respects
with all applicable local, state or federal laws and regulations. Except, in the
case of the Trust Company, for securities and other interests held in a
fiduciary capacity and beneficially owned by third parties and for stock in the
Federal Reserve Bank of Cleveland, none of the BancFirst Subsidiaries holds,
directly or indirectly, any legal or beneficial interest in any shares,
membership units or other equity interest in any Person.

         (c) The authorized capital of each BancFirst Subsidiary, the number of
shares of each which are issued and outstanding and the legal and beneficial
owner of each such share is set forth in Section 4.2(c) of the BancFirst
Disclosure Schedule. Except as set forth in Section 4.2 of the BancFirst
Disclosure Schedule, either BancFirst or BancFirst Bank owns, beneficially and
of record, all of the outstanding common shares of each BancFirst Subsidiary.
All of the outstanding common shares of each BancFirst Subsidiary are
authorized, validly issued, fully paid and nonassessable; were issued in full
compliance with all applicable laws and regulations; and were not issued in
violation of the preemptive right of any shareholder thereof. None of the
BancFirst Subsidiaries has any outstanding class of capital stock other than
common shares as set forth in Section 4.2(c) of the BancFirst Disclosure
Schedule. There are no outstanding subscription rights, options, conversion
rights, warrants or other agreements or commitments of any nature whatsoever
(either firm or conditional) obligating any BancFirst Subsidiary, or BancFirst
or BancFirst Bank, (i) to issue, deliver or sell, cause to be issued, delivered
or sold, any share of such BancFirst Subsidiary, or restricting such BancFirst
Subsidiary from selling any additional shares or (ii) to grant, extend or enter
into any such agreement or commitment.

    4.3 QUALIFICATION. BancFirst, BancFirst Bank, and the BancFirst
Subsidiaries are each duly qualified to do business and in good standing in each
jurisdiction in which such qualification is required or the failure to so
qualify would not have a material adverse effect on the business of BancFirst,
BancFirst Bank, or such BancFirst Subsidiary. BancFirst Bank does not maintain
any branch outside of Ohio or loan production office outside of the States of
Ohio, Michigan, Indiana and Kentucky. The Trust Company does not operate any
trust office or trust representative office outside of the State of Ohio.


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     4.4 AUTHORITY.

         (a) This Agreement has been:

             (i)   Duly executed and delivered by BancFirst and BancFirst Bank;
                   and

             (ii)  Approved by the Boards of Directors of BancFirst and
                   BancFirst Bank.

         (b) The Bank Merger Agreement has been:

             (i)   Duly executed and delivered by BancFirst Bank; (ii) Approved
                   by the Board of Directors of BancFirst Bank; and (iii)
                   Adopted by BancFirst as the sole shareholder of BancFirst
                   Bank.

         (c) Subject to the adoption of this Agreement by the BancFirst
shareholders and to the filing of all requisite Regulatory Applications and the
receipt of all Requisite Regulatory Approvals:

             (i)   BancFirst Bank has all requisite corporate power and
                   authority to enter into this Agreement and the Bank Merger
                   Agreement and, to perform all of its obligations hereunder
                   and thereunder;

             (ii)  The execution and delivery of this Agreement and the Bank
                   Merger Agreement and the consummation of the transactions
                   contemplated hereby and thereby have been duly authorized by
                   all necessary corporate action by BancFirst and BancFirst
                   Bank; and

             (iii) Subject to applicable bankruptcy, insolvency, reorganization
                   and moratorium laws and other laws of general applicability
                   affecting the enforcement of creditors' rights generally, and
                   the effect of rules of law governing specific performance,
                   injunctive relief and other equitable remedies on the
                   enforceability of such documents, and except to the extent
                   such enforceability may be limited by laws relating to safety
                   and soundness of insured depository institutions as set forth
                   in 12 U.S.C. Section 1818(b) or by the appointment of a
                   conservator by the FDIC, (A) this Agreement is the valid and
                   binding agreement of BancFirst, enforceable against BancFirst
                   in accordance with its terms, and (B) this Agreement and the
                   Bank Merger Agreement are the valid and binding agreements of
                   BancFirst Bank, enforceable against BancFirst Bank in
                   accordance with their terms.

     4.5 GOVERNING DOCUMENTS. BancFirst and BancFirst Bank have delivered to UNB
true and accurate copies of the Articles of Incorporation and Code of
Regulations of BancFirst


                                       11
   14

and the Articles of Association and Bylaws of BancFirst Bank and have granted
UNB access to (a) the Articles of Incorporation and Code of Regulations or
Articles of Association and Bylaws of each BancFirst Subsidiary and (b) all
records of all meetings and other corporate actions by the shareholders, Boards
of Directors and Committees of the Boards of Directors of BancFirst, BancFirst
Bank, and each BancFirst Subsidiary, other than records of meetings relating to
the consideration of transactions related to this Agreement. The minute books of
BancFirst and BancFirst Bank contain, in all material respects, complete and
accurate records of all meetings and other corporate actions of the BancFirst
and BancFirst Bank shareholders, Boards of Directors and Committees of the
Boards of Directors, other than records of meetings relating to the
consideration of transactions related to this Agreement.


     4.6 NO CONFLICTS. The execution and delivery of this Agreement and the
consummation of the transactions contemplated hereby, including the Merger and
the Bank Merger, will not:

         (a) Subject to the approval of this Agreement by the requisite vote of
the BancFirst shareholders, conflict with or violate any provision of or result
in the breach of any provision of the Articles of Incorporation or Code of
Regulations of BancFirst or the Articles of Association or Bylaws of BancFirst
Bank;

         (b) Conflict with or violate any provision of or result in the breach
or the acceleration of or entitle any party to accelerate (whether upon or after
the giving of notice of lapse of time or both) any obligation under, or
otherwise materially affect the terms of, any mortgage, Lien, lease, agreement,
license, instrument, order, arbitration award, judgment or decree to which
either BancFirst or BancFirst Bank is a party or by which BancFirst, BancFirst
Bank or their property or assets is bound;

         (c) Require the consent of any party to any agreement or commitment to
which either BancFirst or BancFirst Bank is a party or by which BancFirst,
BancFirst Bank or their property or assets is bound, the failure to obtain which
could, individually or in the aggregate with all the other failures to obtain
required consents, have a material adverse effect on the business, operations or
financial condition of BancFirst and BancFirst Bank, taken as a whole;

         (d) Result in the creation or imposition of any Lien, charge, pledge,
security interest or other encumbrance upon any property or assets of either
BancFirst or BancFirst Bank or give rise to any meritorious cause of action
against either BancFirst or BancFirst Bank; or,

         (e) Subject to the receipt of all Requisite Regulatory Approvals and
the requisite vote of the BancFirst shareholders, violate or conflict with any
applicable law, ordinance, rule or regulation, including, without limitation,
the rules and regulations of the Board of Governors of the Federal Reserve
System ("FRB") or the OCC.

     4.7 CONSENTS. No consent, approval, order or authorization of, or
registration, declaration or filing with, any Governmental Entity is required by
BancFirst, BancFirst Bank, or any BancFirst Subsidiary in connection with the
execution and delivery of this Agreement by BancFirst or BancFirst Bank or the
consummation by BancFirst or BancFirst Bank of the


                                       12
   15

transactions contemplated hereby, including the Merger and the Bank Merger,
except for filings, authorizations, notices, consents or approvals required by
the SEC, the FRB, the OCC, the FDIC, the Ohio Secretary of State and the Ohio
Department of Insurance.

     4.8 BANCFIRST AND BANCFIRST BANK SHARES.

         (a) BANCFIRST CAPITAL. The authorized capital of BancFirst consists of
twenty million (20,000,000) common shares, each without par value, 8,741,834 of
which are issued and outstanding and 837,660 of which are reserved for issuance
upon exercise of options granted in accordance with the BancFirst Option Plan.
All of the issued and outstanding common shares of BancFirst are duly
authorized, validly issued, fully paid and nonassessable and were issued in full
compliance with all applicable laws. BancFirst has no outstanding class of
capital stock other than such common shares.

             (i)   Except for the options to purchase at the per share prices
                   shown in Section 4.8(a)(i) of the BancFirst Disclosure
                   Schedule an aggregate of 441,278 BancFirst Shares granted in
                   accordance with the BancFirst Option Plan and except for the
                   option contained in the Option Agreement, there are no
                   outstanding subscription rights, options, conversion rights,
                   warrants or other agreements, plans or commitments of any
                   nature whatsoever (either firm or conditional) obligating
                   BancFirst (i) to issue, deliver or sell, cause to be issued,
                   delivered or sold, or restricting BancFirst from selling any
                   additional BancFirst Shares; or (ii) to grant, extend or
                   enter into any such agreement, plan or commitment. There are
                   no outstanding stock appreciation, phantom stock or similar
                   rights in respect of BancFirst Shares.

             (ii)  In accordance with the 1997 Bonus Shares Program (hereinafter
                   referred to as the "Bonus Plan"), an aggregate of 20,797
                   BancFirst Shares were awarded to Bonus Plan participants
                   (hereinafter referred to as the "Awarded Bonus Plan Shares").
                   Of the Awarded Bonus Plan Shares, none have been vested on
                   the date hereof (hereinafter referred to as the "Unvested
                   Bonus Plan Shares").

         (b) BANCFIRST BANK CAPITAL. The authorized capital of BancFirst Bank
consists of 3,236,250 common shares, $10.00 par value, all of which are issued
and outstanding and held of record by BancFirst. All of the outstanding common
shares of BancFirst Bank are duly authorized, validly issued, fully paid and
nonassessable; were issued in full compliance with all applicable laws; and were
not issued in violation of the preemptive right of any depositor or shareholder
of BancFirst Bank. BancFirst Bank has no outstanding class of capital stock
other than such common shares. There are no outstanding subscription rights,
options, conversion rights, warrants or other agreements or commitments of any
nature whatsoever (either firm or conditional) obligating BancFirst Bank (i) to
issue, deliver or sell, cause to be issued, delivered or sold, or restricting
BancFirst Bank from selling any additional BancFirst Bank shares or (ii) to
grant, extend or enter into any such agreement or commitment.


                                       13
   16

     4.9 FINANCIAL STATEMENTS.

         (a) The consolidated statements of financial condition as of December
31, 1999 and 2000, of BancFirst and the related consolidated statements of
income, shareholders' equity and cash flows for each of the three years then
ended, examined and reported upon by PricewaterhouseCoopers, LLP, certified
public accountants, complete copies of which have previously been delivered to
UNB (hereinafter referred to as the "BancFirst Audited Financials"), have been
prepared in conformity with generally accepted accounting principles applied on
a consistent basis and fairly present the consolidated financial position of
BancFirst at such dates and the consolidated results of its operations and cash
flows for such periods. The books and records of BancFirst and BancFirst Bank
have been, and are being, maintained in accordance with generally accepted
accounting principles and with any other applicable legal and accounting
requirements and reflect only actual transactions.

         (b) The unaudited balance sheet as of June 30, 2001, of BancFirst and
the related unaudited income statement for the six (6) months then ended,
complete copies of which have previously been delivered to UNB (hereinafter
referred to as the "BancFirst Interim Financials"), fairly present the financial
position of BancFirst at such date and the results of its operations for such
period and in all material respects have been prepared in accordance with
generally accepted accounting principles as applicable to condensed consolidated
financial statements, e.g., without footnotes and certain accruals normally made
at year end, and as applied on a consistent basis with the BancFirst Audited
Financials. All adjustments which are necessary for a fair statement of the
BancFirst Interim Financials have been made.

         (c) The Consolidated Statements of Condition and Income of BancFirst
Bank for the three-month periods ended March 31 and June 30, 2001, together with
the schedules and supplements attached thereto, each as filed with the OCC and
copies of which were previously delivered to UNB by BancFirst (hereinafter
referred to as the "BancFirst Consolidated Statements"), have been prepared in
accordance with accounting practices permitted by the OCC applied on a
consistent basis and fairly present the financial position of BancFirst Bank at
such dates.

         (d) Except as disclosed in the BancFirst Interim Financials, the
BancFirst Consolidated Statements and Section 4.9 of the BancFirst Disclosure
Schedule, as of June 30, 2001, BancFirst had no liabilities or obligations
material to the financial condition of BancFirst, whether accrued, absolute,
contingent or otherwise, and whether due or to become due.

     4.10 CONDUCT OF BUSINESSES. Between June 30, 2001, and the date of this
Agreement, each of BancFirst and BancFirst Bank conducted its businesses only in
the ordinary and usual course, there were no material adverse changes in the
financial condition, assets, liabilities, obligations, properties or business of
BancFirst or BancFirst Bank, and, except as set forth in any of the BancFirst
Audited Financials, the BancFirst Interim Financials, the BancFirst Consolidated
Statements or Section 4.10 of the BancFirst Disclosure Schedule, neither
BancFirst nor BancFirst Bank:


                                       14
   17

         (a) Authorized the creation or issuance of, issued, sold or disposed
of, or created any obligation to issue, sell or dispose of, any stock, notes,
bonds or other securities or any obligation convertible into or exchangeable
for, any shares of its capital stock;

         (b) Except for a per share dividend in the amount of $.145 payable by
BancFirst on September 18, 2001, declared, set aside, paid or made any dividend
or other distributions on its capital stock or directly or indirectly redeemed,
purchased or acquired any shares or entered into any agreement in respect of the
foregoing;

         (c) Effected any stock split, recapitalization, combination, exchange
of shares, readjustment or other reclassification;

         (d) Amended its Articles of Incorporation or Code of Regulations, or,
in the case of BancFirst Bank, its Articles of Association or Bylaws;

         (e) Purchased, sold, assigned or transferred any material tangible
asset or any material patent, trademark, trade name, copyright, license,
franchise, design or other intangible asset or property;

         (f) Mortgaged, pledged or granted or suffered to exist any Lien or
other encumbrance or charge on any assets or properties, tangible or intangible,
except for i) pledges of assets to the Federal Home Loan Bank ("FHLB"); ii)
ordinary course of business restrictions on public funds on deposit; iii) Liens
for taxes not yet due and payable; and iv) such other Liens, encumbrances or
charges which do not materially adversely affect its financial position;

         (g) Waived any rights of material value or canceled any material debts
or claims;

         (h) Incurred any material obligation or liability (absolute or
contingent), including, without limitation, any tax liability or any liability
for borrowings from the FRB of Cleveland or the FHLB of Cincinnati, or paid any
material liability or obligation (absolute or contingent), other than
liabilities and obligations incurred in the ordinary course of business;

         (i) Entered into or amended any employment contract with any of its
officers or increased the compensation payable to any officer or director,
except compensation increases and employment contract renewals made in the
ordinary course;

         (j) Incurred any damage, destruction or similar loss, not covered by
insurance, materially affecting its businesses or properties;

         (k) Acquired any stock or other equity interest in any corporation,
partnership, trust, joint venture or other entity;

         (l) Made any (i) material investment (except investments made in the
ordinary course of business) or (ii) material capital expenditure or commitment
for any material addition to property, plant or equipment; or


                                       15
   18

         (m) Agreed, whether in writing or otherwise, to take any action
described in this Section 4.10.

     4.11 PROPERTIES.


         (a) A description of all fixed assets which are material to BancFirst
and its Subsidiaries considered as a whole owned by each of BancFirst and
BancFirst Bank (directly or through the BancFirst Subsidiaries) has been
delivered to UNB (hereinafter referred to as the "BancFirst Personal Property").
All BancFirst Personal Property has been maintained in good working order,
ordinary wear and tear excepted. BancFirst, BancFirst Bank, or a BancFirst
Subsidiary owns and has good title to all of the BancFirst Personal Property,
free and clear of any mortgage, Lien, pledge, charge, claim, conditional sales
or other agreement, lease, right or encumbrance, except:

             (i)   As set forth in Section 4.11(a) of the BancFirst Disclosure
                   Schedule;

             (ii)  To the extent stated or reserved against in the BancFirst
                   Audited Financials or the BancFirst Interim Financials; and

             (iii) Such other exceptions which are not material in character or
                   amount and do not materially detract from the value of or
                   interfere with the use of the properties or assets subject
                   thereto or affected thereby.

         (b) A description of each parcel of real property owned by BancFirst,
BancFirst Bank, or a BancFirst Subsidiary (other than real property taken by
BancFirst Bank in consideration of debts previously contracted) is set forth in
Section 4.11(b) of the BancFirst Disclosure Schedule (hereinafter referred to
individually as a "BancFirst Parcel" and collectively as the "BancFirst Real
Properties"). Either BancFirst, BancFirst Bank, or a BancFirst Subsidiary is the
owner of each BancFirst Parcel in fee simple and has good and marketable title
to each such BancFirst Parcel, free of any Liens, claims, charges, encumbrances
or security interests of any kind, except:

             (i)   As set forth in Section 4.11(b) of the BancFirst Disclosure
                   Schedule;

             (ii)  Liens for real estate taxes and assessments not yet
                   delinquent; and

             (iii) Utility, access and other easements, rights of way,
                   restrictions and exceptions, none of which impair the
                   BancFirst Real Properties for the use and business being
                   conducted thereon.

         (c) A description of all real property leased by BancFirst, BancFirst
Bank, or a BancFirst Subsidiary is set forth in Section 4.11(c) of the BancFirst
Disclosure Schedule (hereinafter referred to as the "BancFirst Leased Real
Property"). Except as set forth in Section 4.11(c) of the BancFirst Disclosure
Schedule, the Real Property Leases create, in accordance with their terms,
valid, binding and assignable leasehold interests of either BancFirst or



                                       16
   19

BancFirst Bank, or a BancFirst Subsidiary, in all of the BancFirst Leased Real
Property, free and clear of all Liens, claims, charges, encumbrances or security
interests of any kind.

         (d) A description of all personal property leased by BancFirst,
BancFirst Bank, or a BancFirst Subsidiary which requires payment of rentals in
excess of $50,000 per annum is set forth in Section 4.11(d) of the BancFirst
Disclosure Schedule.

         (e) The documentation (hereinafter referred to as "BancFirst Loan
Documentation") governing or relating to the loan and credit-related assets
(hereinafter referred to as the "BancFirst Loan Assets") included within the
loan portfolio of BancFirst Bank is legally sufficient in all material respects
for the purposes intended thereby and creates enforceable rights in favor of
BancFirst Bank in accordance with the terms of such BancFirst Loan
Documentation, subject to applicable bankruptcy, insolvency, reorganization and
moratorium laws and other laws of general applicability affecting the
enforcement of creditors' rights generally, and the effect of rules of law
governing specific performance, injunctive relief and other equitable remedies
on the enforceability of such documents. Each loan included in the BancFirst
Loan Assets has been serviced in all material respects in accordance with
customary lending standards in the ordinary course of business.

    4.12 ALLOWANCE FOR LOAN LOSSES. Except as set forth in a schedule dated
June 30, 2001, as previously delivered to UNB by BancFirst, there was no loan
which was made by either BancFirst or BancFirst Bank and which is reflected as
an asset of either BancFirst or BancFirst Bank on the BancFirst Audited
Financials or the BancFirst Interim Financials that (i) was ninety (90) days or
more delinquent or (ii) has been classified by examiners (regulatory or
internal) as "Substandard," "Doubtful", "Loss" or "Special Mention" (or words of
similar import) as of the date of such Schedule. The allowance for loan losses
as reflected on the BancFirst Audited Financials and the BancFirst Interim
Financials is, in the opinion of BancFirst's management, adequate in all
material respects as of their respective dates under the requirements of
generally accepted accounting principles to provide for reasonably anticipated
losses on outstanding loans, net of recoveries.

    4.13 INVESTMENTS.

         (a) Section 4.13(a) of the BancFirst Disclosure Schedule contains a
true, accurate and complete list of all investments, other than investments in
the BancFirst Loan Assets and the BancFirst Real Properties, and other than
securities and other interests held in a fiduciary capacity and beneficially
owned by third parties or taken in consideration of debts previously contracted,
owned by BancFirst, BancFirst Bank, or a BancFirst Subsidiary (hereinafter
referred to as the "BancFirst Investments") as of June 30, 2001. Except as set
forth in Section 4.13(a) of the BancFirst Disclosure Schedule, the BancFirst
Investments, other than any such investments disposed of in the ordinary course
of business prior to the date hereof, are owned by BancFirst, BancFirst Bank, or
a BancFirst Subsidiary free and clear of all Liens, pledges, claims, security
interests, encumbrances, charges or restrictions of any kind (other than such as
arise in the ordinary course of business from FHLB borrowings or acceptance of
public funds) and may be freely disposed of by BancFirst, BancFirst Bank, or
such BancFirst Subsidiary at any time. Except as set forth in Section 4.13(a) of
the BancFirst Disclosure


                                       17
   20

Schedule, neither BancFirst nor BancFirst Bank, nor any BancFirst Subsidiary, is
a party to, nor has any interest in:


             (i)   Any repurchase agreement, reverse repurchase agreement,
                   collateralized mortgage obligation or any other derivative
                   security; or

             (ii)  Any interest rate swaps, caps, floors, option agreements or
                   any other interest rate risk management agreements.

         (b) Except as set forth in Section 4.13(b) of the BancFirst Disclosure
Schedule, and other than the BancFirst Subsidiaries, neither BancFirst nor
BancFirst Bank owns of record or beneficially the outstanding shares of, or any
equity interest in, any corporation or other business entity, other than
securities and other interests taken in consideration of debts previously
contracted.

    4.14 REPORTS AND RECORDS.

         (a) Each of BancFirst and BancFirst Bank, and each BancFirst
Subsidiary, has filed all reports and maintained all records required to be
filed or maintained by it under various rules and regulations of the SEC, the
FRB, the OCC, the FDIC, the Ohio Department of Insurance and other regulatory
agencies with jurisdiction over BancFirst, BancFirst Bank or any BancFirst
Subsidiary. All such documents and reports complied in all material respects
with applicable requirements of law and regulations in effect at the time of
filing such documents and contained in all material respects the information
required to be stated therein.

         (b) BancFirst has delivered to UNB copies of the following documents,
each of which has been filed with the SEC (hereinafter referred to as the
"BancFirst SEC Filings"):

             (i)   The BancFirst Annual Reports on Form 10-K for the fiscal
                   years ended December 31, 2000 and 1999;

             (ii)  The BancFirst Annual Reports to Shareholders for the fiscal
                   years ended December 31, 2000 and 1999;

             (iii) The BancFirst Proxy Statements for use in connection with the
                   2000 and 1999 Annual Meetings of Shareholders;

             (iv)  The BancFirst Quarterly Reports on Form 10-Q for the quarters
                   ended March 31 and June 30, 2001; and

             (v)   All Form 8-K's filed in 2001.

         The BancFirst SEC Filings did not, as of the dates on which such
reports were filed with the SEC, contain any untrue statement of a material fact
or omit any material fact required to be stated therein or necessary to make the
statements contained therein, in light of the circumstances under which they
were made, not misleading.

                                       18
   21

    4.15 TAXES.

         (a) Except as set forth in Section 4.15(a) of the BancFirst Disclosure
Schedule, each of BancFirst and BancFirst Bank, and each BancFirst Subsidiary,
has duly and timely filed all federal, state, county and local income, profits,
franchise, excise, sales, customs, property, use, occupation, withholding,
social security and other tax and information returns and reports required to
have been filed by each through the date hereof, and has paid or accrued all
taxes and duties (and all interest and penalties with respect thereto) due or
claimed to be due. Neither BancFirst nor BancFirst Bank, nor any BancFirst
Subsidiary, has any liability for any taxes or duties (or interest or penalties
with respect thereto) of any nature whatsoever and there is no basis for any
additional material claims or assessments, other than with respect to
liabilities for taxes and duties which are reflected in the BancFirst Interim
Financials or which may have accrued since June 30, 2001, in the ordinary course
of business.

         (b) No deficiencies for any taxes, assessments or governmental charges
have been proposed, asserted or assessed in writing by any governmental or
taxing authority against BancFirst or BancFirst Bank, or against any BancFirst
Subsidiary, that have not been settled or would not be covered by existing
reserves. Except as set forth in Section 4.15(b) of the BancFirst Disclosure
Schedule, neither BancFirst nor BancFirst Bank, nor any BancFirst Subsidiary:

             (i)   Is a party to any agreement providing for the allocation or
                   sharing of taxes; or

             (ii)  Is required to include in income any adjustment pursuant to
                   Section 481(a) of the Code by reason of the voluntary change
                   in accounting method, nor has any taxing authority proposed
                   in writing any such adjustment or change of accounting
                   method.

         (c) Any amount that will become receivable (whether in cash or property
or the vesting of property) as a result of any of the transactions contemplated
by this Agreement by any employee, officer or director of BancFirst or BancFirst
Bank, or of any BancFirst Subsidiary, who is a "Disqualified Individual," as
such term is defined in proposed Treasury Regulation Section 1.280G-1, under any
employment, severance or termination agreement, other compensation arrangements
or BancFirst Benefit Plan currently in effect will not be characterized as an
"excess parachute payment," as such term is defined in Section 1.280G-1 of the
Code.

    4.16 MATERIAL CONTRACTS.

         (a) Except as set forth in Section 4.16(a) of the BancFirst Disclosure
Schedule, as of the date hereof neither BancFirst nor BancFirst Bank, nor any
BancFirst Subsidiary, is a party to or bound by any written or oral:

             (i)   Contract or commitment for capital expenditures in excess of
                   two hundred thousand dollars ($200,000) for any one project
                   or five hundred thousand dollars ($500,000) in the aggregate;


                                       19
   22

              (ii) Contract or commitment made in the ordinary course of
                   business for the purchase of materials or supplies or for the
                   performance of services involving payments to or by either
                   BancFirst or BancFirst Bank, or any BancFirst Subsidiary, of
                   an amount exceeding two hundred thousand dollars ($200,000)
                   in the aggregate or extending for more than six (6) months
                   from the date hereof;

             (iii) Contract or option for the purchase of any real property;

              (iv) Letter of credit or indemnity calling for payment, upon the
                   conditions stated therein, of more than three hundred
                   thousand dollars ($300,000);

               (v) Guarantee agreement;

              (vi) Instrument granting any person (other than employees acting
                   in the ordinary course of business) authority to transact
                   business on behalf of either BancFirst or BancFirst Bank, or
                   on behalf of a BancFirst Subsidiary;

             (vii) Contracts or commitments relating to outstanding loans and/or
                   commitments to make loans (including unfunded commitments and
                   lines of credit) to any one person or entity (together with
                   "affiliates" of such person or entity) in excess of one
                   million dollars ($1,000,000);

            (viii) Employment, management, consulting, deferred compensation,
                   severance or other similar contract with any director,
                   officer or employee of either BancFirst or BancFirst Bank, or
                   of a BancFirst Subsidiary;

              (ix) Note, debenture or loan agreement pursuant to which either
                   BancFirst or BancFirst Bank, or a BancFirst Subsidiary, has
                   incurred indebtedness, other than deposit liabilities and
                   advances from the FRB of Cleveland or the FHLB of Cincinnati;

               (x) Loan agreement with any director, executive officer or ten
                   percent (10%) or greater shareholder of BancFirst, BancFirst
                   Bank, or any BancFirst Subsidiary, or to the knowledge of
                   BancFirst and BancFirst Bank, any Person controlling,
                   controlled by or under common control with, or a member of
                   the immediate family of, any of the foregoing;

              (xi) Any contract which would constitute or involves a "covered
                   transaction" with an "affiliate" under Sections 23A or 23B of
                   the Federal Reserve Act; or


                                       20
   23

             (xii) Commitment or agreement to do any of the foregoing. Contracts
                   set forth in Section 4.16 of the BancFirst Disclosure
                   Schedule are hereinafter collectively referred to as the
                   "BancFirst Contracts."

         (b) None of BancFirst, BancFirst Bank, or any BancFirst Subsidiary is
in material default under any of the BancFirst Contracts, nor has there occurred
any event that, with the lapse of time or the giving of notice or both, would
constitute such a default.

    4.17 INSURANCE. All material properties and operations of each of BancFirst
and BancFirst Bank are adequately insured for its benefit. The performance by
the officers and employees of each of BancFirst and BancFirst Bank of their
duties is bonded in such amounts and against such risks as are usually insured
against or bonded by entities similarly situated, under valid and enforceable
policies of insurance or bonds issued by insurers or bonding companies of
recognized responsibility, financial or otherwise.

    4.18 ACTIONS AND SUITS. Except as set forth in Section 4.18 of the
BancFirst Disclosure Schedule, and except for routine claims and foreclosure
litigation arising in the ordinary course of business, there are no actions,
suits or proceedings or investigations pending or, to the knowledge of
BancFirst, threatened against or affecting the business, operations or financial
condition of either BancFirst or BancFirst Bank, or of any BancFirst Subsidiary,
in any court or before any federal, state, municipal or other governmental
department, commission, board, bureau, agency or instrumentality, and neither
BancFirst or BancFirst Bank has any knowledge of any basis for any such action,
suit, proceeding or investigation.

    4.19 PERMITS AND LICENSES. Each of BancFirst and BancFirst Bank, and each
BancFirst Subsidiary, has all material permits, licenses, orders and approvals
of all federal, state or local governmental or regulatory bodies required for
BancFirst, BancFirst Bank and each BancFirst Subsidiary to conduct its business
as presently conducted, and all such material permits, licenses, orders and
approvals are in full force and effect, without the threat of suspension or
cancellation. None of such permits, licenses, orders or approvals will be
adversely affected by the consummation of the transactions contemplated by this
Agreement.

    4.20 EMPLOYEE BENEFIT PLANS; ERISA.

         (a) Section 4.20 of the BancFirst Disclosure Schedule contains a true
and complete list of all qualified pension or profit-sharing plans, deferred
compensation, consulting, bonus, group insurance plans or agreements and all
other incentive, welfare or employee benefit plans or agreements, including, but
not limited to, all "employee benefit plans," as defined in Section 3(3) of the
Employee Retirement Income Security Act of 1974, as amended (hereinafter
referred to as "ERISA"), which covers any employee or former employee of
BancFirst or BancFirst Bank, or of any BancFirst Subsidiary or any affiliate or
under which BancFirst or BancFirst Bank, or of any BancFirst Subsidiary or any
affiliate has any liability (hereinafter collectively referred to as the
"BancFirst Benefit Plans"). For purposes of this Section 4.20, "affiliate" of
any person or entity means any other person or entity which, together with such
person or entity, would be treated as a single employer under Section 414 of the
Code or is an "affiliate," whether or not incorporated, as defined in Section
407(d)(7) of ERISA, of such


                                       21
   24

person or entity. With respect to such BancFirst Benefit Plans, BancFirst has
made available true and complete copies of all:

             (i)   BancFirst Benefit Plan documents and amendments thereto;

             (ii)  Trust agreements and amendments thereto;

             (iii) All written interpretations and summaries;

             (iv)  The three most recent annual reports on IRS Form 5500;

             (v)   The most recent IRS determination letters (and any pending
                   request for such) for each BancFirst Benefit Plan which is
                   intended to be qualified under Section 401(a) of the Code
                   have been delivered to UNB;

             (vi)  A copy of the most recent summary plan description required
                   under ERISA with respect thereto, and all supplements or
                   modifications thereto; and

             (vii) A copy of the three most recent annual reports prepared by an
                   accountant, actuary or other similar expert with respect to
                   any disclosure regarding (i) pensions in accordance with
                   Statement of Financial Accounting Standards No. 87, (ii)
                   other post-retirement benefits in accordance with Statement
                   of Financial Accounting Standards No. 106, and (iii)
                   stock-based compensation in accordance with Statement of
                   Financial Accounting Standards No. 123.

         (b) None of the reports or other materials delivered pursuant to
Sections 4.20(a)(iv) and 4.20(a)(vii) includes any untrue statement of a
material fact or omits to state a material fact necessary in order to make the
statements, in the light of the circumstances under which they were made, not
misleading.

         (c) Each BancFirst Benefit Plan which constitutes an "employee pension
plan," as defined in Section 3(2) of ERISA, is and has been administered in
material compliance with its governing documents and the applicable provisions
of ERISA and any such employee pension plan which is intended to be qualified
under the provisions of Section 401(a) of the Code, is and has been administered
in material compliance with the applicable provisions of the Code.

         (d) Each BancFirst Benefit Plan which constitutes an "employee welfare
benefit plan," as defined in Section 3(1) of ERISA, is and has been administered
in material compliance with its governing documents and the applicable
provisions of ERISA and each BancFirst Benefit Plan which constitutes a "group
health plan," as defined in Section 5000(b)(1) of the Code, is and has been
administered in material compliance with the continuation of coverage provisions
contained in Section 4980B of the Code.


                                       22
   25

         (e) Each BancFirst Benefit Plan which is not an "employee benefit
plan," as defined in Section 3(3) of ERISA, is and has been administered in
material compliance with its Governing Documents and with any and all state or
federal laws applicable to such BancFirst Benefit Plan. Nothing done or omitted
to be done and no transaction or holding of any asset under or in connection
with any BancFirst Benefit Plan has or will make BancFirst, BancFirst Bank, a
BancFirst Subsidiary or any affiliate liable for any tax pursuant to Sections
4971-4980E of the Code. There is no pending or threatened litigation,
arbitration, disputed claim, adjudication, audit, examination or other
proceeding with respect to any BancFirst Benefit Plan or any fiduciary or
administrator thereof in their capacities as such (other than the submission of
participant claims for benefits in the ordinary course of operation of such
BancFirst Benefit Plans).

         (f) The market value of assets under each "employee pension plan" (as
defined above) which is subject to the provisions of Title IV of ERISA, equals
or exceeds the present value of all vested and nonvested liabilities thereunder
determined in accordance with Pension Benefit Guaranty Corporation (hereafter
referred to as the "PBGC") methods, factors and assumptions applicable to an
employee pension plan terminating on the date for determination. No "accumulated
funding deficiency," as defined in Section 412 of the Code, has been incurred
with respect to any BancFirst Benefit Plan, whether or not waived. Full payment
has been made of all amounts which BancFirst or BancFirst Bank or any affiliate
is required to have paid as contributions to or benefits under any BancFirst
Benefit Plan as of the end of the most recent plan year thereof and there are no
unfunded obligations under any BancFirst Benefit Plan. No condition exists and
no event has occurred that could constitute grounds for termination of any
BancFirst Benefit Plan, and neither BancFirst, BancFirst Bank, a BancFirst
Subsidiary nor any affiliate has incurred any material liability under Title IV
of ERISA arising in connection with the termination of any BancFirst Benefit
Plan covered or previously covered by Title IV of ERISA.

         (g) BancFirst does not maintain any BancFirst Benefit Plan which
provides post-retirement medical, dental or life insurance benefits to any
former employee of BancFirst, BancFirst Bank or any BancFirst Subsidiary nor is
BancFirst obligated to provide any such benefit to any current employee upon his
or her retirement, except for the continuation coverage required under Section
4980B of the Code.

         (h) Neither BancFirst nor BancFirst Bank, nor any BancFirst Subsidiary,
participates in, or has ever been obligated to contribute to, any multi-employer
plan as such term is defined in Section 3(37) of ERISA.

         (i) None of BancFirst, BancFirst Bank, a BancFirst Subsidiary nor any
BancFirst Benefit Plan maintained by any of BancFirst, BancFirst Bank, or a
BancFirst Subsidiary, nor any fiduciary of any such BancFirst Benefit Plan, has
incurred any material liability to the PBGC, the United States Department of
Labor or to the IRS with respect to a BancFirst Benefit Plan.


                                       23
   26

         (j) No prohibited transaction (which shall mean any transaction
prohibited by Section 406 of ERISA and not exempt under Section 408 of ERISA)
has occurred with respect to any "employee benefit plan" (as defined above)
maintained by either BancFirst, BancFirst Bank or any BancFirst Subsidiary;

             (i)   Which would result in the imposition, directly or indirectly,
                   of an excise tax under Section 4975 of the Code; or

             (ii)  The correction of which would have a material adverse effect
                   on the financial condition, results of operations or business
                   of BancFirst. No "reportable event," within the meaning of
                   Section 4043 of ERISA, and no event described in Section
                   4041, 4042, 4062 or 4063 of ERISA has occurred in connection
                   with any BancFirst Benefit Plan.

         (k) Each employee pension plan (as defined above) which is intended to
be an employee stock ownership plan, as defined in Section 4975(e)(7) of the
Code, is and has been administered in substantial compliance with the applicable
provisions of Sections 4975 and 409 of the Code and the regulations promulgated
by the IRS thereunder and, any outstanding loan to which any such employee stock
ownership plan is a party constitutes an "exempt loan," as described in Section
54.4975-7 of the regulations promulgated by the IRS.

         (l) There has been no amendment to, written interpretation or
announcement (whether or not written) relating to, or change in employee
participation or coverage under, any BancFirst Benefit Plan, which would
increase the expense of maintaining such BancFirst Benefit Plan above the level
of the expense incurred in respect thereof for the plan year ended immediately
prior to the date hereof.

         (m) Except as set forth in the BancFirst Disclosure Schedule or as
expressly provided in this Agreement, the consummation of the transactions
contemplated by this Agreement will not (A) entitle any current or former
employee or officer of BancFirst or any affiliate to severance pay, unemployment
compensation or any other payment, or (B) accelerate the time of payment or
vesting, or increase the amount of compensation or benefits due any such
employee or officer.

         (n) With respect to each BancFirst Benefit Plan, no "reportable event"
within the meaning of Section 4043 of ERISA (excluding any such event for which
the thirty (30) day notice requirement has been waived under the regulations to
Section 4043 of ERISA) nor any event described in Section 4062, 4063 or 4041 of
ERISA has occurred.

         (o) No amounts payable under the BancFirst Benefit Plans will fail to
be deductible for federal income tax purposes by virtue of section 280G of the
Code.


                                       24
   27

    4.21 ENVIRONMENTAL PROTECTION

         (a) Except as set forth in Section 4.21 of the BancFirst Disclosure
Schedule:

             (i)   To the knowledge of BancFirst, each of BancFirst, BancFirst
                   Bank, and the BancFirst Property is, and has been at all
                   times, in material compliance with all applicable
                   Environmental Laws;

             (ii)  No investigations, inquiries, orders, hearings, actions or
                   other proceedings by or before any court or governmental
                   agency have been issued, are pending or, to the knowledge of
                   BancFirst or BancFirst Bank, threatened against either
                   BancFirst or BancFirst Bank, or in connection with the
                   BancFirst Property;

             (iii) No claims have been made or, to the knowledge of BancFirst or
                   BancFirst Bank, threatened at any time against either
                   BancFirst or BancFirst Bank, with respect to the BancFirst
                   Property relating to actual or alleged violation of any
                   Environmental Law with respect to the BancFirst Property or
                   relating to damage, contribution, cost recovery,
                   compensation, loss or injury resulting from any Hazardous
                   Substance with respect to the BancFirst Property;

             (iv)  To the knowledge of BancFirst, no Hazardous Substances have
                   been integrated into any BancFirst Property or any component
                   thereof in violation of Environmental Laws;

             (v)   [INTENTIONALLY LEFT BLANK];

             (vi)  The BancFirst Property has not been used by BancFirst or
                   BancFirst Bank for the storage, disposal or treatment of
                   Hazardous Substances, except as allowed by applicable law,
                   has not been contaminated by Hazardous Substances in material
                   violation of any applicable Environmental Laws, nor has been
                   used for the storage or use of any underground or aboveground
                   storage tanks in material violation of any applicable
                   Environmental Laws; and

             (vii) Material permits, registrations and other authorizations
                   necessary for either BancFirst or BancFirst Bank, or the
                   BancFirst Property to operate in material compliance with all
                   Environmental Laws are currently in force and are identified
                   in Section 4.21 of the BancFirst Disclosure Schedule.


         (b) As used in this Agreement:

             (i)   "BancFirst Property" means all real and personal property now
                   or previously owned, leased, occupied or managed by either
                   BancFirst or BancFirst Bank or any Subsidiary of either or
                   any Person or entity whose liability for any matter has or
                   may have



                                       25
   28

                   been related or assumed by BancFirst either contractually or
                   are by operation of law.

             (ii)  "Environmental Laws" means all federal, state, local and
                   other laws, regulations, rules, standards, ordinances,
                   orders, decrees, and judgments relating to pollution, the
                   environment, occupational health and safety, or the
                   protection of human health, all as may be from time to time
                   amended.

             (iii) "Hazardous Substances" means any and all substances or
                   materials which are classified or considered to be hazardous
                   or toxic to human health or the environment under any
                   applicable Environmental Laws and shall include, without
                   limitation, any "hazardous substances" as defined in Section
                   101(14) of CERCLA (42 USC Section 9601(14)) or regulations
                   promulgated thereunder, any "toxic and hazardous substances"
                   as defined in 29 CFR Part 1910, petroleum and its byproducts,
                   asbestos, polychlorinated biphenyls, nuclear fuel or
                   materials, lead and lead-containing substances, and
                   urea-formaldehyde.]

    4.22 EMPLOYMENT MATTERS. Each of BancFirst and BancFirst Bank is in
material compliance with all federal, state or other applicable laws respecting
employment and employment practices, terms and conditions of employment and
wages and hours. No unfair labor practice complaint against either BancFirst or
BancFirst Bank is pending before any governmental agency or court and there is
no labor strike, dispute, slowdown or stoppage actually pending or, to the
knowledge of either BancFirst or BancFirst Bank, threatened against or involving
either BancFirst or BancFirst Bank. No representation question exists in respect
of the employees of either BancFirst or BancFirst Bank and no labor grievance
which might have a material adverse effect upon either BancFirst or BancFirst
Bank, or the conduct of its businesses is pending or, to the knowledge of
BancFirst, threatened. No arbitration proceeding arising out of or under any
collective bargaining agreement is pending and no claim therefore has been
asserted against either BancFirst or BancFirst Bank. No collective bargaining
agreement is currently in effect or is currently being negotiated by either
BancFirst or BancFirst Bank. 4.23 BROKERS. All negotiations relating to this
Agreement and the transactions contemplated hereby have been carried on without
the intervention of any person, other than Sandler, O'Neill & Partners, acting
on behalf of BancFirst or BancFirst Bank pursuant to an agreement disclosed in
the BancFirst Disclosure Schedule or in such manner as to give rise to any valid
claim against BancFirst or BancFirst Bank for any broker's or finder's fee or
similar compensation.

    4.24 STOCK OWNERSHIP. Except as set forth in Section 4.24 of the BancFirst
Disclosure Schedule, neither BancFirst nor any of its "affiliates" or
"associates," as the terms "affiliates" and "associates" are defined in Section
1704.01(C)(1) of the ORC, are "beneficial owners," as the term "beneficial
owners" is defined in Section 1704.01(C)(4) of the ORC, of any of the UNB
Shares.


                                       26
   29

    4.25 REGULATORY MATTERS. Except as set forth in Section 4.25 of the
BancFirst Disclosure Schedule, neither BancFirst nor BancFirst Bank, nor any
BancFirst Subsidiary, is subject or is party to, or has received any notice or
advice that it may become subject or party to, any investigation with respect
to, any cease-and-desist order, agreement, consent agreement, memorandum of
understanding or other regulatory enforcement action, proceeding or order with
or by, or is a party to any commitment letter or similar undertaking to, or is
subject to any directive by, any regulatory agency that currently restricts the
conduct of its business or that currently affects its capital adequacy, credit
policies, management or business (hereinafter referred to as a "Regulatory
Agreement"), nor has BancFirst, BancFirst Bank, or any BancFirst Subsidiary,
been advised by any regulatory agency that it is considering issuing or
requesting any such Regulatory Agreement. Except as set forth in Section 4.25 of
the BancFirst Disclosure Schedule, there is no unresolved violation, with
respect to any report or statement relating to any examinations of BancFirst,
BancFirst Bank, or any BancFirst Subsidiary. BancFirst, BancFirst Bank and each
BancFirst Subsidiary has paid all assessments made or imposed by any
Governmental Entity.

    4.26 NON-BANKING ACTIVITIES. BancFirst is not engaged in any activity,
either directly or indirectly through one or more of the BancFirst Subsidiaries
or other equity investments, which is not permitted to be engaged in by a
financial holding company or by a subsidiary or other enterprise through which
such activity is conducted. BancFirst Bank is not engaged in any activity,
either directly or indirectly through one or more of the BancFirst Subsidiaries
or other equity investments, which is not permitted to be engaged in by a
national banking association or by a subsidiary or other enterprise through
which such activity is conducted.

    4.27 FIDUCIARY RESPONSIBILITY. During the applicable statute of limitations
period:

         (a) Each of BancFirst Bank and the Trust Company has properly
administered all accounts for which it acts as a fiduciary or agent, including,
but not limited to, accounts for which it serves as a trustee, agent, custodian,
personal representative, guardian, conservator or investment advisor, in
accordance with the terms of the Governing Documents and applicable state and
federal law and regulations and common law; and

         (b) Neither BancFirst Bank nor the Trust Company, nor any director,
officer or employee of BancFirst Bank or the Trust Company acting on behalf of
BancFirst Bank or the Trust Company, has committed any breach of trust with
respect to any such fiduciary or agency account, and the accountings for each
such fiduciary or agency account are true and correct and accurately reflect the
assets of such fiduciary or agency account.

         (c) To the knowledge of BancFirst or BancFirst Bank, there is no
investigation or inquiry by any regulatory agency pending or threatened against
or affecting BancFirst Bank or the Trust Company relating to the compliance by
BancFirst Bank or the Trust Company with sound fiduciary principles and
applicable regulations.

    4.28 EMPLOYMENT AGREEMENTS. Section 4.16 of the BancFirst Disclosure
Schedule lists each agreement, arrangement, commitment or contract (whether
written or oral) for the employment, retention or engagement, or with respect to
the severance, of any present or former officer, director, employee, agent,
consultant or other person or entity to which BancFirst or


                                       27
   30

BancFirst Bank, or any BancFirst Subsidiary, is a party to or bound by and
which, by its terms, is not terminable by BancFirst or BancFirst Bank, or a
BancFirst Subsidiary, on thirty (30) days written notice or less without the
payment of any amount by reason of such termination. Copies of each written
agreement, arrangement, commitment or contract listed in Section 4.16 of the
BancFirst Disclosure Schedule have been previously made available to UNB.

    4.29 CERTAIN OPERATIONAL MATTERS.

         (a) Neither BancFirst nor BancFirst Bank is a party to any agreement or
subject to any arrangement which would prevent, limit or restrict it from the
sale, lease or other disposition of its main offices or any branch office.

         (b) Except as set forth in Section 4.29 of the BancFirst Disclosure
Schedule, the consummation of the Merger or the Bank Merger shall not result in
the termination or cancellation before its stated expiration of any contract to
which BancFirst or BancFirst Bank is a party or cause them to incur any
financial penalty, liquidated damages, assessment or other costs solely by
reason of such mergers.

         (c) All interest rate swaps, caps, floors and option agreements and
other interest rate risk management arrangements, whether entered into for the
account of BancFirst or for the account of a customer of BancFirst or one of its
Subsidiaries, were entered into in the ordinary course of business and, to
BancFirst's knowledge, in accordance with prudent banking practice and
applicable rules, regulations and policies of any regulatory authority having
jurisdiction over the same and with counter parties believed to be financially
responsible at the time and are legal, valid and binding obligations of
BancFirst or one of its Subsidiaries enforceable in accordance with their terms
(except as may be limited by bankruptcy, insolvency, moratorium, reorganization
or similar laws affecting the rights of creditors generally and the availability
of equitable remedies), and are in full force and effect. BancFirst and each of
its Subsidiaries have duly performed in all material respects all of their
material obligations thereunder to the extent that such obligations to perform
have accrued; and, to BancFirst's knowledge, there are no material breaches,
violations or defaults or allegations or assertions of such by any party
thereunder.

    4.30 INTELLECTUAL PROPERTY. BancFirst, BancFirst Bank and each BancFirst
Subsidiary owns or possesses valid and binding licenses and other rights to use
without payment of any material amount all material patents, copyrights, trade
secrets, trade names, service marks and trademarks and software used in its
businesses, all of which are set forth in Section 4.30 of the BancFirst
Disclosure Schedule, and none of BancFirst, BancFirst Bank or any BancFirst
Subsidiary has received any notice of conflict with respect thereto that asserts
the right of others.

    4.31 TRANSACTIONS WITH AFFILIATES. All "covered transactions" between
BancFirst Bank and an "affiliate" thereof within the meaning of Sections 23A and
23B of the Federal Reserve Act have been in compliance with such provisions. All
"covered transactions" between the Trust Company and an "affiliate" thereof
within the meaning of Sections 23A and 23B of the Federal Reserve Act have been
in compliance with such provisions.


                                       28
   31

    4.32 STATEMENTS. None of the information supplied or to be supplied by
BancFirst and BancFirst Bank for inclusion in this Agreement or in any documents
filed with any regulatory agency in connection with the transactions
contemplated by this Agreement shall, at the respective times such documents are
filed, and at the time of the BancFirst shareholders' meeting to consider the
Merger, contain any untrue statement of a material fact, or omit to state any
material fact necessary in order to make the statements made therein, in light
of the circumstances under which they are made, not misleading.

    4.33 BROKERED DEPOSITS. BancFirst Bank holds no brokered deposits.

ARTICLE V. REPRESENTATIONS AND WARRANTIES OF UNB AND UNB BANK

         UNB and the UNB Bank represent and warrant to BancFirst that each of
the following statements is true and accurate in all material respects, except
as otherwise disclosed in a schedule provided by UNB and the UNB Bank to
BancFirst prior to the execution of this Agreement (the "UNB Disclosure
Schedule"). The UNB Disclosure Schedule shall be arranged in paragraphs
corresponding to the lettered Sections and Subsections contained in this Article
V, and the disclosure in any letter paragraph shall qualify only the
corresponding Section or Subsection in this Article V.

     5.1 ORGANIZATION AND STANDING.

         (a) UNB is a corporation duly organized, validly existing and in good
standing under the laws of the State of Ohio and has the corporate power and
authority to own or hold under lease all of its properties and assets and to
conduct its business and operations as presently conducted. UNB is registered as
a bank holding company under the BHCA. UNB has filed an election to become, and
presently is, a "financial holding company" under 12 C.F.R. Section 225.82, has
not received any notice from the FRB pursuant to 12 C.F.R. Section 225.82(e)(1),
continues to satisfy all requirements for financial holding company status under
12 C.F.R. Section 225.81, and is not subject to any limitation under 12 C.F.R.
Sections 225.83 or 225.84. UNB is in compliance in all material respects with
all applicable local, state or federal laws and regulations.

         (b) UNB Bank is a national banking association duly organized and
validly existing under the NBA and has the corporate power and authority to own
or hold under lease all of its properties and assets and to conduct its business
and operations as presently conducted. Except as set forth in Section 5.1(b) of
the UNB Disclosure Schedule, the deposit accounts of UNB Bank are insured up to
applicable limits by the BIF or the Savings Association Insurance Fund of the
FDIC, and UNB Bank has paid all deposit insurance premiums and assessments
required by applicable law. UNB Bank is in compliance in all material respects
with all applicable local, state or federal laws and regulations, including
without limitation, the Equal Credit Opportunity Act, the Fair Housing Act, the
Community Reinvestment Act, the Home Mortgage Disclosure Act and all other
applicable fair lending laws and other laws relating to discriminatory business
practices.

     5.2 SUBSIDIARIES.

         (a) United Banc Financial Services, Inc. is a corporation duly
organized and validly existing under the laws of the State of Ohio ("UNB
Financial"). United Financial


                                       29
   32

Advisors, Inc. is a corporation duly organized and validly existing under the
laws of the State of Ohio ("UNB Advisors"). United Portfolio Management
Corporation is a corporation duly organized and validly existing under the laws
of the State of Delaware ("UNB Management"). UNB Financial, UNB Advisors and UNB
Management are collectively referred to hereafter as the "UNB Subsidiaries".

         (b) Each UNB Subsidiary has the full corporate power, right, authority
and governmental authorizations to own or lease its properties and assets and to
carry on its business as it now is being conducted in all material respects.
Each UNB Subsidiary is in compliance in all material respects with all
applicable local, state or federal laws and regulations. None of the UNB
Subsidiaries holds, directly or indirectly, any legal or beneficial interest in
any shares, membership units or other equity interest in any Person.

         (c) The authorized capital of each UNB Subsidiary, the number of shares
of each which are issued and outstanding and the legal and beneficial owner of
each such share is set forth in Section 5.2 of the UNB Disclosure Schedule.
Either UNB or UNB Bank owns, beneficially and of record, all of the outstanding
common shares of each UNB Subsidiary. All of the outstanding common shares of
each UNB Subsidiary are authorized, validly issued, fully paid and
nonassessable; were issued in full compliance with all applicable laws and
regulations; and were not issued in violation of the preemptive right of any
shareholder thereof. None of the UNB Subsidiaries has any outstanding class of
capital stock other than common shares as set forth in Section 5.2(c) of the UNB
Disclosure Schedule. There are no outstanding subscription rights, options,
conversion rights, warrants or other agreements or commitments of any nature
whatsoever (either firm or conditional) obligating any UNB Subsidiary, or UNB or
UNB Bank, (i) to issue, deliver or sell, cause to be issued, delivered or sold,
any share of such UNB Subsidiary, or restricting such UNB Subsidiary from
selling any additional shares or (ii) to grant, extend or enter into any such
agreement or commitment.

     5.3 QUALIFICATION. UNB, UNB Bank and the UNB Subsidiaries are each duly
qualified to do business and in good standing in each jurisdiction in which such
qualification is required or the failure to so qualify would not have a material
adverse effect on the business of UNB, UNB Bank or such UNB Subsidiary. UNB Bank
does not maintain any branch, loan production office or trust representative
office outside of the State of Ohio.

     5.4 AUTHORITY.

         (a) This Agreement has been:

             (i)   Duly executed and delivered by UNB and UNB Bank; and

             (ii)  Approved by the Boards of Directors of UNB and UNB Bank.

         (b) The Bank Merger Agreement has been:

             (i)   Duly executed and delivered by UNB Bank;

             (ii)  Approved by the Board of Directors of UNB Bank; and


                                       30
   33

             (iii) Adopted by UNB as the sole shareholder of UNB Bank.

         (c) Subject to the adoption of this Agreement by the UNB shareholders
and to the filing of all requisite Regulatory Applications and the receipt of
all Requisite Regulatory Approvals:

             (i)   UNB Bank has all requisite corporate power and authority to
                   enter into this Agreement and the Bank Merger Agreement and,
                   to perform all of its obligations hereunder and thereunder;

             (ii)  The execution and delivery of this Agreement and the Bank
                   Merger Agreement and the consummation of the transactions
                   contemplated hereby and thereby have been duly authorized by
                   all necessary corporate action by UNB and UNB Bank; and

             (iii) Subject to applicable bankruptcy, insolvency, reorganization
                   and moratorium laws and other laws of general applicability
                   affecting the enforcement of creditors' rights generally, and
                   the effect of rules of law governing specific performance,
                   injunctive relief and other equitable remedies on the
                   enforceability of such documents, and except to the extent
                   such enforceability may be limited by laws relating to safety
                   and soundness of insured depository institutions as set forth
                   in 12 U.S.C. Section 1818(b) or by the appointment of a
                   conservator by the FDIC, (A) this Agreement is the valid and
                   binding agreement of UNB, enforceable against UNB in
                   accordance with its terms, and (B) this Agreement and the
                   Bank Merger Agreement are the valid and binding agreements of
                   UNB Bank, enforceable against UNB Bank in accordance with
                   their terms.

     5.5 GOVERNING DOCUMENTS. UNB and UNB Bank have delivered to BancFirst true
and accurate copies of the Articles of Incorporation and Code of Regulations of
UNB and the Articles of Association and Bylaws of UNB Bank and have granted
BancFirst access to (a) the Articles of Incorporation and Code of Regulations of
each UNB Subsidiary and (b) all records of all meetings and other corporate
actions by the shareholders, Boards of Directors and Committees of the Boards of
Directors of UNB, UNB Bank, and each UNB Subsidiary, other than records of
meetings relating to the consideration of transactions related to this
Agreement. The minute books of UNB and UNB Bank contain, in all material
respects, complete and accurate records of all meetings and other corporate
actions of the UNB and UNB Bank shareholders, Boards of Directors and Committees
of the Boards of Directors, other than records of meetings relating to the
consideration of transactions related to this Agreement.

     5.6 NO CONFLICTS. The execution and delivery of this Agreement and the
consummation of the transactions contemplated hereby, including the Merger and
the Bank Merger, will not:


                                       31
   34

         (a) Subject to the approval of this Agreement by the requisite vote of
the UNB shareholders, conflict with or violate any provision of or result in the
breach of any provision of the Articles of Incorporation or Code of Regulations
of UNB or the Articles of Association or Bylaws of UNB Bank;

         (b) Conflict with or violate any provision of or result in the breach
or the acceleration of or entitle any party to accelerate (whether upon or after
the giving of notice of lapse of time or both) any obligation under, or
otherwise materially affect the terms of, any mortgage, Lien, lease, agreement,
license, instrument, order, arbitration award, judgment or decree to which
either UNB or UNB Bank is a party or by which UNB, UNB Bank or their property or
assets is bound;

         (c) Require the consent of any party to any agreement or commitment to
which either UNB or UNB Bank is a party or by which UNB, UNB Bank or their
property or assets is bound, the failure to obtain which could, individually or
in the aggregate with all the other failures to obtain required consents, have a
material adverse effect on the business, operations or financial condition of
UNB and UNB Bank, taken as a whole;

         (d) Result in the creation or imposition of any Lien, charge, pledge,
security interest or other encumbrance upon any property or assets of either UNB
or UNB Bank or give rise to any meritorious cause of action against either UNB
or UNB Bank; or,

         (e) Subject to the receipt of all requisite regulatory approvals and
the requisite vote of the UNB shareholders, violate or conflict with any
applicable law, ordinance, rule or regulation, including, without limitation,
the rules and regulations of the FRB or the OCC.

     5.7 CONSENTS. No consent, approval, order or authorization of, or
registration, declaration or filing with, any Governmental Entity is required by
UNB, UNB Bank or any UNB Subsidiary in connection with the execution and
delivery of this Agreement by UNB or UNB Bank or the consummation by UNB or UNB
Bank of the transactions contemplated hereby, including the Merger and the Bank
Merger, except for filings, authorizations, notices, consents or approvals
required by the SEC, the FRB, the OCC, the FDIC, the Ohio Secretary of State and
the Ohio Department of Insurance.

     5.8 UNB AND UNB BANK SHARES.

         (a) UNB CAPITAL. The authorized capital of UNB consists of fifty
million (50,000,000) common shares, each without par value, 10,476,941 of which
are issued and outstanding and 1,254,583 of which are reserved for issuance upon
exercise of options granted in accordance with UNB Plan I and UNB Plan II. All
of the issued and outstanding common shares of UNB are duly authorized, validly
issued, fully paid and nonassessable and were issued in full compliance with all
applicable laws. UNB has no outstanding class of capital stock other than such
common shares.

             (i)   Except for the options to purchase at the per share prices
                   shown in the UNB Disclosure Schedule an aggregate of 928,624
                   UNB Shares granted in accordance with the UNB Plan I and the
                   UNB Plan II and except for the option contained in the Option


                                       32
   35

                   Agreement, there are no outstanding subscription rights,
                   options, conversion rights, warrants or other agreements,
                   plans or commitments of any nature whatsoever (either firm or
                   conditional) obligating UNB (i) to issue, deliver or sell,
                   cause to be issued, delivered or sold, or restricting UNB
                   from selling any additional UNB common shares; or (ii) to
                   grant, extend or enter into any such agreement, plan or
                   commitment. There are no outstanding stock appreciation,
                   phantom stock or similar rights in respect of UNB Shares.

         (b) UNB BANK CAPITAL. The authorized capital of UNB Bank consists of
__________ common shares, each without par value, 269,325 of which are issued
and outstanding and held of record by UNB. All of the outstanding common shares
of UNB Bank are duly authorized, validly issued, fully paid and nonassessable;
were issued in full compliance with all applicable laws; and were not issued in
violation of the preemptive right of any depositor or shareholder of UNB Bank.
UNB Bank has no outstanding class of capital stock other than such common
shares. There are no outstanding subscription rights, options, conversion
rights, warrants or other agreements or commitments of any nature whatsoever
(either firm or conditional) obligating UNB Bank (i) to issue, deliver or sell,
cause to be issued, delivered or sold, or restricting UNB Bank from selling any
additional UNB Bank shares or (ii) to grant, extend or enter into any such
agreement or commitment.

     5.9 FINANCIAL STATEMENTS.

         (a) The consolidated statements of financial condition as of December
31, 1999 and 2000, of UNB and the related consolidated statements of income,
shareholders' equity and cash flows for each of the three years then ended,
examined and reported upon by Crowe, Chizek & Company, LLP, certified public
accountants, complete copies of which have previously been delivered to
BancFirst (hereinafter referred to as the "UNB Audited Financials"), have been
prepared in conformity with generally accepted accounting principles applied on
a consistent basis and fairly present the consolidated financial position of UNB
at such dates and the consolidated results of its operations and cash flows for
such periods. The books and records of UNB and UNB Bank have been, and are
being, maintained in accordance with generally accepted accounting principles
and with any other applicable legal and accounting requirements and reflect only
actual transactions.

         (b) The unaudited balance sheet as of June 30, 2001, of UNB and the
related unaudited income statement for the six (6) months then ended, complete
copies of which have previously been delivered to BancFirst (hereinafter
referred to as the "UNB Interim Financials"), fairly present the financial
position of UNB at such date and the results of its operations for such period
and in all material respects have been prepared in accordance with generally
accepted accounting principles as applicable to condensed consolidated financial
statements, e.g., without footnotes and certain accruals normally made at year
end, and as applied on a consistent basis with the UNB Audited Financials. All
adjustments which are necessary for a fair statement of the UNB Interim
Financials have been made.


                                       33
   36

         (c) The Consolidated Statements of Condition and Income of UNB Bank for
the three-month periods ended March 31 and June 30, 2001, together with the
schedules and supplements attached thereto, each as filed with the OCC and
copies of which were previously delivered to BancFirst by UNB (hereinafter
referred to as the "UNB Consolidated Statements"), have been prepared in
accordance with accounting practices permitted by the OCC applied on a
consistent basis and fairly present the financial position of UNB Bank at such
dates.

         (d) Except as disclosed in the UNB Interim Financials, the UNB
Consolidated Statements and Section 5.9 of the UNB Disclosure Schedule, as of
June 30, 2001, UNB had no liabilities or obligations material to the financial
condition of UNB, whether accrued, absolute, contingent or otherwise, and
whether due or to become due.

    5.10 CONDUCT OF BUSINESSES. Between June 30, 2001, and the date of this
Agreement, each of UNB and UNB Bank conducted its businesses only in the
ordinary and usual course, there were no material adverse changes in the
financial condition, assets, liabilities, obligations, properties or business of
UNB or UNB Bank, and, except as set forth in any of the UNB Audited Financials,
the UNB Interim Financials, the UNB Consolidated Statements or Section 5.10 of
the UNB Disclosure Schedule, neither UNB nor UNB Bank:

         (a) Authorized the creation or issuance of, issued, sold or disposed
of, or created any obligation to issue, sell or dispose of, any stock, notes,
bonds or other securities or any obligation convertible into or exchangeable
for, any shares of its capital stock;

         (b) Except for a per share dividend in the amount of $.125 payable by
UNB on September 14, 2001, declared, set aside, paid or made any dividend or
other distributions on its capital stock or directly or indirectly redeemed,
purchased or acquired any shares or entered into any agreement in respect of the
foregoing;

         (c) Effected any stock split, recapitalization, combination, exchange
of shares, readjustment or other reclassification;

         (d) Amended its Articles of Incorporation or Code of Regulations, or,
in the case of UNB Bank, its Articles of Association or Bylaws;

         (e) Purchased, sold, assigned or transferred any material tangible
asset or any material patent, trademark, trade name, copyright, license,
franchise, design or other intangible asset or property;

         (f) Mortgaged, pledged or granted or suffered to exist any Lien or
other encumbrance or charge on any assets or properties, tangible or intangible,
except for i) pledges of assets to the FHLB; ii) ordinary course of business
restrictions on public funds on deposit; iii) Liens for taxes not yet due and
payable; and iv) such other Liens, encumbrances or charges which do not
materially adversely affect its financial position;

         (g) Waived any rights of material value or canceled any material debts
or claims;


                                       34
   37

         (h) Incurred any material obligation or liability (absolute or
contingent), including, without limitation, any tax liability or any liability
for borrowings from the FRB of Cleveland or the FHLB, or paid any material
liability or obligation (absolute or contingent), other than liabilities and
obligations incurred in the ordinary course of business;

         (i) Entered into or amended any employment contract with any of its
officers or increased the compensation payable to any officer or director,
except compensation increases and employment contract renewals made in the
ordinary course;

         (j) Incurred any damage, destruction or similar loss, not covered by
insurance, materially affecting its businesses or properties;

         (k) Acquired any stock or other equity interest in any corporation,
partnership, trust, joint venture or other entity;

         (l) Made any (i) material investment (except investments made in the
ordinary course of business) or (ii) material capital expenditure or commitment
for any material addition to property, plant or equipment; or

         (m) Agreed, whether in writing or otherwise, to take any action
described in this Section 5.10.

    5.11 PROPERTIES.

         (a) A description of all fixed assets which are material to UNB and its
subsidiaries considered as a whole owned by each of UNB and UNB Bank (directly
or through the UNB Subsidiaries) has been delivered to BancFirst (hereinafter
referred to as the "UNB Personal Property"). All UNB Personal Property has been
maintained in good working order, ordinary wear and tear excepted. UNB, UNB Bank
or a UNB Subsidiary owns and has good title to all of the UNB Personal Property,
free and clear of any mortgage, Lien, pledge, charge, claim, conditional sales
or other agreement, lease, right or encumbrance, except:

             (i)   As set forth in Section 5.11(a) of the UNB Disclosure
                   Schedule;

             (ii)  To the extent stated or reserved against in the UNB Audited
                   Financials or the UNB Interim Financials; and

             (iii) Such other exceptions which are not material in character or
                   amount and do not materially detract from the value of or
                   interfere with the use of the properties or assets subject
                   thereto or affected thereby.

         (b) A description of each parcel of real property owned by UNB, UNB
Bank, or a UNB Subsidiary (other than real property taken by UNB Bank in
consideration of debts previously contracted) is set forth in Section 5.11(b) of
the UNB Disclosure Schedule (hereinafter referred to individually as a "UNB
Parcel" and collectively as the "UNB Real Properties"). Either UNB, UNB Bank or
a UNB Subsidiary is the owner of each UNB Parcel in


                                       35
   38

fee simple and has good and marketable title to each such UNB Parcel, free of
any Liens, claims, charges, encumbrances or security interests of any kind,
except:

             (i)   As set forth in Section 5.11(b) of the UNB Disclosure
                   Schedule;

             (ii)  Liens for real estate taxes and assessments not yet
                   delinquent; and

             (iii) Utility, access and other easements, rights of way,
                   restrictions and exceptions, none of which impair the UNB
                   Real Properties for the use and business being conducted
                   thereon.

         (c) A description of all real property leased by UNB, UNB Bank or any
UNB Subsidiary is set forth in Section 5.11(c) of the UNB Disclosure Schedule
(hereinafter referred to as the "UNB Leased Real Property"). Except as set forth
in Section 5.11(c) of the UNB Disclosure Schedule, the Real Property Leases
create, in accordance with their terms, valid, binding and assignable leasehold
interests of either UNB or UNB Bank, or a UNB Subsidiary, in all of the UNB
Leased Real Property, free and clear of all Liens, claims, charges, encumbrances
or security interests of any kind.

         (d) A description of all personal property leased by UNB, UNB Bank or a
UNB Subsidiary which requires payment of rentals in excess of $50,000 per annum
is set forth in Section 5.11(d) of the UNB Disclosure Schedule.

         (e) The documentation (hereinafter referred to as "UNB Loan
Documentation") governing or relating to the loan and credit-related assets
(hereinafter referred to as the "UNB Loan Assets") included within the loan
portfolio of UNB Bank is legally sufficient in all material respects for the
purposes intended thereby and creates enforceable rights in favor of UNB Bank in
accordance with the terms of such UNB Loan Documentation, subject to applicable
bankruptcy, insolvency, reorganization and moratorium laws and other laws of
general applicability affecting the enforcement of creditors' rights generally,
and the effect of rules of law governing specific performance, injunctive relief
and other equitable remedies on the enforceability of such documents. Each loan
included in the UNB Loan Assets has been serviced in all material respects in
accordance with customary lending standards in the ordinary course of business.

    5.12 ALLOWANCE FOR LOAN LOSSES. Except as set forth in a schedule
dated June 30, 2001, as previously delivered to BancFirst by UNB, there was no
loan which was made by UNB, UNB Bank or UNB Financial and which is reflected as
an asset of UNB, UNB Bank or UNB Financial on the UNB Audited Financials or the
UNB Interim Financials that (i) was ninety (90) days or more delinquent or (ii)
has been classified by examiners (regulatory or internal) as "Substandard,"
"Doubtful", "Loss" or "Special Mention" (or words of similar import). The
allowance for loan losses as reflected on the UNB Audited Financials and the UNB
Interim Financials is, in the opinion of UNB's management, adequate in all
material respects as of their respective dates under the requirements of
generally accepted accounting principles to provide for reasonably anticipated
losses on outstanding loans, net of recoveries.

    5.13 INVESTMENTS.


                                       36
   39

         (a) Section 5.13(a) of the UNB Disclosure Schedule contains a true,
accurate and complete list of all investments, other than investments in the UNB
Loan Assets and the UNB Real Properties, and other than securities and other
interests held in a fiduciary capacity and beneficially owned by third parties
or taken in consideration of debts previously contracted, owned by UNB, UNB
Bank, or a UNB Subsidiary (hereinafter referred to as the "UNB Investments") as
of July 31, 2001. Except as set forth in Section 5.13(a) of the UNB Disclosure
Schedule, the UNB Investments, other than any such investments disposed of in
the ordinary course of business prior to the date hereof, are owned by UNB, UNB
Bank, or a UNB Subsidiary free and clear of all Liens, pledges, claims, security
interests, encumbrances, charges or restrictions of any kind (other than such as
arise in the ordinary course of business from FHLB borrowings or acceptance of
public funds) and may be freely disposed of by UNB, UNB Bank or such UNB
Subsidiary at any time. Except as set forth in Section 5.13(a) of the UNB
Disclosure Schedule, neither UNB nor UNB Bank, nor any UNB Subsidiary, is a
party to, nor has any interest in:

             (i)   Any repurchase agreement, reverse repurchase agreement,
                   collateralized mortgage obligation or any other derivative
                   security; or

            (ii)   Any interest rate swaps, caps, floors, option agreements or
                   any other interest rate risk management agreements.

         (b) Except as set forth in Section 5.13(a) of the UNB Disclosure
Schedule, and other than the UNB Subsidiaries, neither UNB nor UNB Bank owns of
record or beneficially the outstanding shares of, or any equity interest in, any
corporation or other business entity, other than securities and other interests
taken in consideration of debts previously contracted.

    5.14 REPORTS AND RECORDS.

         (a) Each of UNB and UNB Bank, and each UNB Subsidiary, has filed all
reports and maintained all records required to be filed or maintained by it
under various rules and regulations of the SEC, the FRB, the OCC, the FDIC, the
Ohio Department of Insurance, the Ohio Division of Commerce and other regulatory
agencies with jurisdiction over UNB, UNB Bank or any UNB Subsidiary. All such
documents and reports complied in all material respects with applicable
requirements of law and regulations in effect at the time of filing such
documents and contained in all material respects the information required to be
stated therein.

         (b) UNB has delivered to BancFirst copies of the following documents,
each of which has been filed with the SEC (hereinafter referred to as the "UNB
SEC Filings"):

             (i)   The UNB Annual Reports on Form 10-K for the fiscal years
                   ended December 31, 2000 and 1999;

             (ii)  The UNB Annual Reports to Shareholders for the fiscal years
                   ended December 31, 2000 and 1999;

             (iii) The UNB Proxy Statements for use in connection with the 2000
                   and 1999 Annual Meetings of Shareholders;


                                       37
   40

             (iv)  The UNB Quarterly Reports on Form 10-Q for the quarters ended
                   March 31 and June 30, 2001; and

             (v)   All Form 8-K's filed in 2001.

The UNB SEC Filings did not, as of the dates on which such reports were filed
with the SEC, contain any untrue statement of a material fact or omit any
material fact required to be stated therein or necessary to make the statements
contained therein, in light of the circumstances under which they were made, not
misleading.


    5.15 TAXES.

         (a) Except as set forth in Section 5.15(a) of the UNB Disclosure
Schedule, each of UNB and UNB Bank, and each UNB Subsidiary, has duly and timely
filed all federal, state, county and local income, profits, franchise, excise,
sales, customs, property, use, occupation, withholding, social security and
other tax and information returns and reports required to have been filed by
each through the date hereof, and has paid or accrued all taxes and duties (and
all interest and penalties with respect thereto) due or claimed to be due.
Neither UNB nor UNB Bank, nor any UNB Subsidiary, has any liability for any
taxes or duties (or interest or penalties with respect thereto) of any nature
whatsoever and there is no basis for any additional material claims or
assessments, other than with respect to liabilities for taxes and duties which
are reflected in the UNB Interim Financials or which may have accrued since June
30, 2001, in the ordinary course of business.

         (b) No deficiencies for any taxes, assessments or governmental charges
have been proposed, asserted or assessed in writing by any governmental or
taxing authority against UNB or UNB Bank, or against any UNB Subsidiary, that
have not been settled or would not be covered by existing reserves. Except as
set forth in Section 5.15(b) of the UNB Disclosure Schedule, neither UNB nor UNB
Bank, nor any UNB Subsidiary:

             (i)   Is a party to any agreement providing for the allocation or
                   sharing of taxes; or

             (ii)  Is required to include in income any adjustment pursuant to
                   Section 481(a) of the Code by reason of the voluntary change
                   in accounting method, nor has any taxing authority proposed
                   in writing any such adjustment or change of accounting
                   method.

         (c) Any amount that will become receivable (whether in cash or property
or the vesting of property) as a result of any of the transactions contemplated
by this Agreement by any employee, officer or director of UNB or UNB Bank, or of
any UNB Subsidiary, who is a Disqualified Individual under any employment,
severance or termination agreement, other compensation arrangements or UNB
Benefit Plan currently in effect will not be characterized as an "excess
parachute payment," as such term is defined in Section 1.280G-1 of the Code.


                                       38
   41

    5.16 MATERIAL CONTRACTS.

         (a) Except as set forth in Section 5.16(a) of the UNB Disclosure
Schedule, neither UNB nor UNB Bank, nor any UNB Subsidiary, as of the date
hereof is a party to or bound by any written or oral:

               (i) Contract or commitment for capital expenditures in excess of
                   two hundred thousand dollars ($200,000) for any one project
                   or five hundred thousand dollars ($500,000) in the aggregate;

              (ii) Contract or commitment made in the ordinary course of
                   business for the purchase of materials or supplies or for the
                   performance of services involving payments to or by either
                   UNB or UNB Bank, or any UNB Subsidiary, of an amount
                   exceeding two hundred thousand dollars ($200,000) in the
                   aggregate or extending for more than six (6) months from the
                   date hereof;

             (iii) Contract or option for the purchase of any real property;

              (iv) Letter of credit or indemnity calling for payment, upon the
                   conditions stated therein, of more than three hundred
                   thousand dollars ($300,000);

               (v) guarantee agreement;

              (vi) Instrument granting any person ( other than employees acting
                   in the ordinary course of business) authority to transact
                   business on behalf of either UNB or UNB Bank, or on behalf of
                   a UNB Subsidiary;

             (vii) Contracts or commitments relating to outstanding loans and/or
                   commitments to make loans (including unfunded commitments and
                   lines of credit) to any one person or entity (together with
                   "affiliates" of such person or entity) in excess of one
                   million dollars ($1,000,000);

            (viii) Employment, management, consulting, deferred compensation,
                   severance or other similar contract with any director,
                   officer or employee of either UNB or UNB Bank, or of a UNB
                   Subsidiary;

              (ix) Note, debenture or loan agreement pursuant to which either
                   UNB or UNB Bank, or a UNB Subsidiary, has incurred
                   indebtedness, other than deposit liabilities and advances
                   from the FRB of Cleveland and the FHLB;

               (x) Loan agreement with any director, executive officer or ten
                   percent (10%) or greater shareholder of UNB, UNB Bank, or any
                   UNB Subsidiary, or to the knowledge of UNB and UNB Bank, any



                                       39
   42

                   Person controlling, controlled by or under common control
                   with, or a member of the immediate family of, any of the
                   foregoing;

             (xi)  Any contract which would constitute or involves a "covered
                   transaction" with an "affiliate" under Sections 23A or 23B of
                   the Federal Reserve Act; or

             (xii) Commitment or agreement to do any of the foregoing. Contracts
                   set forth in Section 5.16 of the UNB Disclosure Schedule are
                   hereinafter collectively referred to as the "UNB Contracts."

         (b) None of UNB, UNB Bank, or any UNB Subsidiary is in material default
under any of the UNB Contracts, nor has there occurred any event that, with the
lapse of time or the giving of notice or both, would constitute such a default.

    5.17 INSURANCE. All material properties and operations of each of UNB and
UNB Bank are adequately insured for its benefit. The performance by the officers
and employees of each of UNB and UNB Bank of their duties is bonded in such
amounts and against such risks as are usually insured against or bonded by
entities similarly situated, under valid and enforceable policies of insurance
or bonds issued by insurers or bonding companies of recognized responsibility,
financial or otherwise.

    5.18 ACTIONS AND SUITS. Except as set forth in Section 5.18 of the UNB
Disclosure Schedule, and except for routine claims and foreclosure litigation
arising in the ordinary course of business, there are no actions, suits or
proceedings or investigations pending or, to the knowledge of UNB, threatened
against or affecting the business, operations or financial condition of either
UNB or UNB Bank, or of any UNB Subsidiary, in any court or before any federal,
state, municipal or other governmental department, commission, board, bureau,
agency or instrumentality, and neither UNB or UNB Bank has any knowledge of any
basis for any such action, suit, proceeding or investigation.

    5.19 PERMITS AND LICENSES. Each of UNB and UNB Bank, and each UNB
Subsidiary, has all material permits, licenses, orders and approvals of all
federal, state or local governmental or regulatory bodies required for UNB, UNB
Bank and each UNB Subsidiary to conduct its business as presently conducted, and
all such material permits, licenses, orders and approvals are in full force and
effect, without the threat of suspension or cancellation. None of such permits,
licenses, orders or approvals will be adversely affected by the consummation of
the transactions contemplated by this Agreement.

    5.20 EMPLOYEE BENEFIT PLANS; ERISA.

         (a) Section 5.20 of the UNB Disclosure Schedule contains a true and
complete list of all qualified pension or profit-sharing plans, deferred
compensation, consulting, bonus, group insurance plans or agreements and all
other incentive, welfare or employee benefit plans or agreements, including, but
not limited to, all "employee benefit plans," as defined in Section 3(3) of
ERISA, which covers any employee or former employee of UNB or UNB Bank, or of
any UNB Subsidiary or any affiliate or under which UNB or UNB Bank, or of any
UNB


                                       40
   43

Subsidiary or any affiliate has any liability (hereinafter collectively referred
to as the "UNB Benefit Plans"). For purposes of this Section 5.20, "affiliate"
of any person or entity means any other person or entity which, together with
such person or entity, would be treated as a single employer under Section 414
of the Code or is an "affiliate," whether or not incorporated, as defined in
Section 407(d)(7) of ERISA, of such person or entity. With respect to such UNB
Benefit Plans, UNB has made available true and complete copies of all:

             (i)   UNB Benefit Plan documents and amendments thereto;

             (ii)  Trust agreements and amendments thereto;

             (iii) all written interpretations and summaries;

             (iv)  The three most recent annual reports on IRS Form 5500;

             (v)   The most recent IRS determination letters (and any pending
                   request for such) for each UNB Benefit Plan which is intended
                   to be qualified under Section 401(a) of the Code have been
                   delivered to BancFirst;

             (vi)  A copy of the most recent summary plan description required
                   under ERISA with respect thereto, and all supplements or
                   modifications thereto; and

             (vii) A copy of the three most recent annual reports prepared by an
                   accountant, actuary or other similar expert with respect to
                   any disclosure regarding (i) pensions in accordance with
                   Statement of Financial Accounting Standards No. 87, (ii)
                   other post-retirement benefits in accordance with Statement
                   of Financial Accounting Standards No. 106, and (iii)
                   stock-based compensation in accordance with Statement of
                   Financial Accounting Standards No. 123.

         (b) None of the reports or other materials delivered pursuant to
Sections 5.20(a)(iv) and 5.20(a)(vii) includes any untrue statement of a
material fact or omits to state a material fact necessary in order to make the
statements, in the light of the circumstances under which they were made, not
misleading.

         (c) Each UNB Benefit Plan which constitutes an "employee pension plan,"
as defined in Section 3(2) of ERISA, is and has been administered in material
compliance with its Governing Documents and the applicable provisions of ERISA
and any such employee pension plan which is intended to be qualified under the
provisions of Section 401(a) of the Code, is and has been administered in
material compliance with the applicable provisions of the Code.

         (d) Each UNB Benefit Plan which constitutes an "employee welfare
benefit plan," as defined in Section 3(1) of ERISA, is and has been administered
in material compliance with its Governing Documents and the applicable
provisions of ERISA and each UNB Benefit Plan which constitutes a "group health
plan," as defined in Section 5000(b)(1) of the Code, is and


                                       41
   44

has been administered in material compliance with the continuation of coverage
provisions contained in Section 4980B of the Code.

         (e) Each UNB Benefit Plan which is not an "employee benefit plan," as
defined in Section 3(3) of ERISA, is and has been administered in material
compliance with its Governing Documents and with any and all state or federal
laws applicable to such UNB Benefit Plan. Nothing done or omitted to be done and
no transaction or holding of any asset under or in connection with any UNB
Benefit Plan has or will make UNB, UNB Bank, a UNB Subsidiary or any affiliate
liable for any tax pursuant to Sections 4971-4980E of the Code. There is no
pending or threatened litigation, arbitration, disputed claim, adjudication,
audit, examination or other proceeding with respect to any UNB Benefit Plan or
any fiduciary or administrator thereof in their capacities as such (other than
the submission of participant claims for benefits in the ordinary course of
operation of such UNB Benefit Plans).

         (f) The market value of assets under each "employee pension plan" (as
defined above) which is subject to the provisions of Title IV of ERISA, equals
or exceeds the present value of all vested and nonvested liabilities thereunder
determined in accordance with PBGC methods, factors and assumptions applicable
to an employee pension plan terminating on the date for determination. No
"accumulated funding deficiency," as defined in Section 412 of the Code, has
been incurred with respect to any UNB Benefit Plan, whether or not waived. Full
payment has been made of all amounts which UNB or UNB Bank or any affiliate is
required to have paid as contributions to or benefits under any UNB Benefit Plan
as of the end of the most recent plan year thereof and there are no unfunded
obligations under any UNB Benefit Plan. No condition exists and no event has
occurred that could constitute grounds for termination of any UNB Benefit Plan,
and neither UNB, UNB Bank, a UNB Subsidiary nor any affiliate has incurred any
material liability under Title IV of ERISA arising in connection with the
termination of any UNB Benefit Plan covered or previously covered by Title IV of
ERISA.

         (g) UNB does not maintain any UNB Benefit Plan which provides
post-retirement medical, dental or life insurance benefits to any former
employee of either UNB, UNB Bank or any UNB Subsidiary nor is UNB obligated to
provide any such benefit to any current employee upon his or her retirement,
except for the continuation coverage required under Section 4980B of the Code.

         (h) Neither UNB nor UNB Bank, nor any UNB Subsidiary participates in,
or has ever been obligated to contribute to, any multi-employer plan as such
term is defined in Section 3(37) of ERISA.

         (i) None of UNB, UNB Bank, a UNB Subsidiary nor any UNB Benefit Plan
maintained by any of UNB, UNB Bank, or a UNB Subsidiary, nor any fiduciary of
any such UNB Benefit Plan, has incurred any material liability to the PBGC, the
United States Department of Labor or to the IRS with respect to a UNB Benefit
Plan.

         (j) No prohibited transaction (which shall mean any transaction
prohibited by Section 406 of ERISA and not exempt under Section 408 of ERISA)
has occurred with respect to any "employee benefit plan" (as defined above)
maintained by either UNB, UNB Bank or any UNB Subsidiary;


                                       42
   45

             (i)   Which would result in the imposition, directly or indirectly,
                   of an excise tax under Section 4975 of the Code; or

             (ii)  The correction of which would have a material adverse effect
                   on the financial condition, results of operations or business
                   of UNB. No "reportable event," within the meaning of Section
                   4043 of ERISA, and no event described in Section 4041, 4042,
                   4062 or 4063 of ERISA has occurred in connection with any UNB
                   Benefit Plan.

         (k) Each employee pension plan (as defined above) which is intended to
be an employee stock ownership plan, as defined in Section 4975(e)(7) of the
Code, is and has been administered in substantial compliance with the applicable
provisions of Sections 4975 and 409 of the Code and the regulations promulgated
by the Internal Revenue Service (hereinafter referred to as the "IRS")
thereunder and, any outstanding loan to which any such employee stock ownership
plan is a party constitutes an "exempt loan," as described in Section 54.4975-7
of the regulations promulgated by the IRS.

         (l) There has been no amendment to, written interpretation or
announcement (whether or not written) relating to, or change in employee
participation or coverage under, any UNB Benefit Plan, which would increase the
expense of maintaining such UNB Benefit Plan above the level of the expense
incurred in respect thereof for the plan year ended immediately prior to the
date hereof.

         (m) Except as set forth in the UNB Disclosure Schedule or as expressly
provided in this Agreement, the consummation of the transactions contemplated by
this Agreement will not (A) entitle any current or former employee or officer of
UNB or any affiliate to severance pay, unemployment compensation or any other
payment, or (B) accelerate the time of payment or vesting, or increase the
amount of compensation or benefits due any such employee or officer.

         (n) With respect to each UNB Benefit Plan, no "reportable event" within
the meaning of Section 4043 of ERISA (excluding any such event for which the
thirty (30) day notice requirement has been waived under the regulations to
Section 4043 of ERISA) nor any event described in Section 4062, 4063 or 4041 of
ERISA has occurred.

         (o) No amounts payable under the UNB Benefit Plans will fail to be
deductible for federal income tax purposes by virtue of section 280G of the
Code.

    5.21 ENVIRONMENTAL PROTECTION.

         (a) Except as set forth in Section 5.21 of the UNB Disclosure Schedule:

             (i)   To the knowledge of UNB, each of UNB, UNB Bank, and the UNB
                   Property is, and has been at all times, in material
                   compliance with all applicable Environmental Laws;


                                       43
   46

             (ii)  No investigations, inquiries, orders, hearings, actions or
                   other proceedings by or before any court or governmental
                   agency have been issued, are pending or, to the knowledge of
                   UNB or UNB Bank, threatened against either UNB or UNB Bank,
                   or in connection with the UNB Property;

             (iii) No claims have been made or, to the knowledge of UNB or UNB
                   Bank, threatened at any time against either UNB or UNB Bank,
                   with respect to the UNB Property, relating to actual or
                   alleged violation of any Environmental Law with respect to
                   the UNB Property or relating to damage, contribution, cost
                   recovery, compensation, loss or injury resulting from any
                   Hazardous Substance with respect to the UNB Property;

             (iv)  To the knowledge of UNB, no Hazardous Substances have been
                   integrated into any UNB Property or any component thereof in
                   violation of Environmental Laws;

             (v)   [INTENTIONALLY LEFT BLANK];

             (vi)  The UNB Property has not been used by UNB or UNB Bank for the
                   storage, disposal or treatment of Hazardous Substances,
                   except as allowed by applicable law, has not been
                   contaminated by Hazardous Substances, in material violation
                   of any applicable Environmental Laws, nor has been used for
                   the storage or use of any underground or aboveground storage
                   tanks in material violation of any applicable Environmental
                   Laws; and

             (vii) Material permits, registrations and other authorizations
                   necessary for either UNB or UNB Bank, or the UNB Property to
                   operate in material compliance with all Environmental Laws
                   are currently in force and are identified in Section 5.21 of
                   the UNB Disclosure Schedule.

         (b) As used in this Agreement, "UNB Property" means all real and
personal property now or previously owned, leased, occupied or managed by either
UNB or UNB Bank or any Subsidiary of either or any person or entity whose
liability for any matter has or may have been related or assumed by UNB either
contractually or are by operation of law.

    5.22 EMPLOYMENT MATTERS. Each of UNB and UNB Bank is in material compliance
with all federal, state or other applicable laws respecting employment and
employment practices, terms and conditions of employment and wages and hours. No
unfair labor practice complaint against either UNB or UNB Bank is pending before
any governmental agency or court and there is no labor strike, dispute, slowdown
or stoppage actually pending or, to the knowledge of either UNB or UNB Bank,
threatened against or involving either UNB or UNB Bank. No representation
question exists in respect of the employees of either UNB or UNB Bank and no
labor grievance which might have a material adverse effect upon either UNB or
UNB Bank, or


                                       44
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the conduct of its businesses is pending or, to the knowledge of UNB,
threatened. No arbitration proceeding arising out of or under any collective
bargaining agreement is pending and no claim therefore has been asserted against
either UNB or UNB Bank. No collective bargaining agreement is currently in
effect or is currently being negotiated by either UNB or UNB Bank.

    5.23 BROKERS. All negotiations relating to this Agreement and the
transactions contemplated hereby have been carried on without the intervention
of any person, other than Stifel Nicolaus, acting solely on behalf of UNB and
UNB Bank pursuant to an agreement disclosed in the UNB Disclosure Schedule, or
in such manner as to give rise to any valid claim against BancFirst or BancFirst
Bank for any broker's or finder's fee or similar compensation. 5.24 STOCK
OWNERSHIP. Except as set forth in Section 5.24 of the UNB Disclosure Schedule,
neither UNB nor any of its "affiliates" or "associates," as the terms
"affiliates" and "associates" are defined in Section 1704.01(C)(1) of the ORC,
are "beneficial owners," as the term "beneficial owners" is defined in Section
1704.01(C)(4) of the ORC, of any of the BancFirst Shares.

    5.25 REGULATORY MATTERS. Except as set forth in Section 5.25 of the UNB
Disclosure Schedule, neither UNB nor UNB Bank, nor any UNB Subsidiary, is
subject or is party to, or has received any notice or advice that it may become
subject or party to, any investigation with respect to, any Regulatory
Agreement, or is a party to, or is subject to, or has been a recipient of, or
has adopted any board resolutions at the request of, any Regulatory Agreement,
nor has UNB, UNB Bank, or any UNB Subsidiary been advised by any regulatory
agency that it is considering issuing or requesting any such Regulatory
Agreement. Except as set forth in Section 5.25 of the UNB Disclosure Schedule,
there is no unresolved violation, with respect to any report or statement
relating to any examinations of UNB, UNB Bank, or any UNB Subsidiary. UNB, UNB
Bank and each UNB Subsidiary has paid all assessments made or imposed by any
Governmental Entity.

    5.26 NON-BANKING ACTIVITIES. UNB is not engaged in any activity, either
directly or indirectly through one or more of the UNB Subsidiaries or other
equity investments, which is not permitted to be engaged in by a financial
holding company or by a subsidiary or other enterprise through which such
activity is conducted. UNB Bank is not engaged in any activity, either directly
or indirectly through one or more of the UNB Subsidiaries or other equity
investments, which is not permitted to be engaged in by a national banking
association or by a subsidiary or other enterprise through which such activity
is conducted.

    5.27 FIDUCIARY RESPONSIBILITY. During the applicable statute of
limitations period:

         (a) UNB Bank has properly administered all accounts for which it acts
as a fiduciary or agent, including, but not limited to, accounts for which it
serves as a trustee, agent, custodian, personal representative, guardian,
conservator or investment advisor, in accordance with the terms of the Governing
Documents and applicable state and federal law and regulations and common law;
and

         (b) Neither UNB Bank, nor any director, officer or employee of UNB Bank
acting on behalf of UNB Bank, has committed any breach of trust with respect to
any such


                                       45
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fiduciary or agency account, and the accountings for each such fiduciary or
agency account are true and correct and accurately reflect the assets of such
fiduciary or agency account.

         (c) To the knowledge of UNB or UNB Bank, there is no investigation or
inquiry by any regulatory agency pending or threatened against or affecting UNB
Bank relating to the compliance by UNB Bank with sound fiduciary principles and
applicable regulations.

    5.28 EMPLOYMENT AGREEMENTS. Section 5.16 of the UNB Disclosure Schedule
lists each agreement, arrangement, commitment or contract (whether written or
oral) for the employment, retention or engagement, or with respect to the
severance, of any present or former officer, director, employee, agent,
consultant or other person or entity to which UNB or UNB Bank, or any UNB
Subsidiary, is a party to or bound by and which, by its terms, is not terminable
by UNB or UNB Bank, or a UNB Subsidiary, on thirty (30) days written notice or
less without the payment of any amount by reason of such termination. Copies of
each written agreement, arrangement, commitment or contract listed in Section
5.16 of the UNB Disclosure Schedule have been previously made available to
BancFirst.

    5.29 CERTAIN OPERATIONAL MATTERS.

         (a) Neither UNB nor UNB Bank is a party to any agreement or subject to
any arrangement which would prevent, limit or restrict it from the sale, lease
or other disposition of its main offices or any branch office.

         (b) Except as set forth in Section 5.29 of the UNB Disclosure Schedule,
the consummation of the Merger or the Bank Merger shall not result in the
termination or cancellation before its stated expiration of any contract to
which UNB or UNB Bank is a party or cause them to incur any financial penalty,
liquidated damages, assessment or other costs solely by reason of such mergers.

         (c) All interest rate swaps, caps, floors and option agreements and
other interest rate risk management arrangements, whether entered into for the
account of UNB or for the account of a customer of UNB or one of its
Subsidiaries, were entered into in the ordinary course of business and, to UNB's
knowledge, in accordance with prudent banking practice and applicable rules,
regulations and policies of any regulatory authority having jurisdiction over
the same and with counter parties believed to be financially responsible at the
time and are legal, valid and binding obligations of UNB or one of its
Subsidiaries enforceable in accordance with their terms (except as may be
limited by bankruptcy, insolvency, moratorium, reorganization or similar laws
affecting the rights of creditors generally and the availability of equitable
remedies), and are in full force and effect. UNB and each of its Subsidiaries
have duly performed in all material respects all of their material obligations
thereunder to the extent that such obligations to perform have accrued; and, to
UNB's knowledge, there are no material breaches, violations or defaults or
allegations or assertions of such by any party thereunder.

    5.30 INTELLECTUAL PROPERTY. UNB, UNB Bank and each UNB Subsidiary owns
or possesses valid and binding licenses and other rights to use without payment
of any material amount all material patents, copyrights, trade secrets, trade
names, service marks and trademarks and software used in its businesses, all of
which are set forth in Section 5.30 of the UNB


                                       46
   49

Disclosure Schedule, and none of UNB, UNB Bank or any UNB Subsidiary has
received any notice of conflict with respect thereto that asserts the right of
others.

    5.31 TRANSACTIONS WITH AFFILIATES. All "covered transactions" between
UNB Bank and an "affiliate" thereof within the meaning of Sections 23A and 23B
of the Federal Reserve Act have been in compliance with such provisions. All
"covered transactions" between the Trust Company and an "affiliate" thereof
within the meaning of Sections 23A and 23B of the Federal Reserve Act have been
in compliance with such provisions.

    5.32 STATEMENTS. None of the information supplied or to be supplied by
UNB and UNB Bank for inclusion in this Agreement or in any documents filed with
any regulatory agency in connection with the transactions contemplated by this
Agreement shall, at the respective times such documents are filed, and at the
time of the UNB shareholders' meeting to consider the Merger, contain any untrue
statement of a material fact, or omit to state any material fact necessary in
order to make the statements made therein, in light of the circumstances under
which they are made, not misleading.

    5.33 BROKERED DEPOSITS. UNB Bank holds no brokered deposits.

                             ARTICLE VI. COVENANTS

    6.1 CONDUCT OF BUSINESS PENDING THE EFFECTIVE TIME. Each of BancFirst,
BancFirst Bank, UNB, and UNB Bank agrees as to itself and the BancFirst
Subsidiaries and the UNB Subsidiaries, as applicable, that, from and after the
date hereof until the Effective Time, except insofar as the other party shall
otherwise consent in writing (such consent not to be unreasonably withheld or
delayed) or except as otherwise expressly contemplated by this Agreement, the
Bank Merger Agreement or the Option Agreements:

         (a) The business of it and the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, will be conducted only in the ordinary and usual
course and, to the extent consistent therewith, it and the BancFirst
Subsidiaries or the UNB Subsidiaries, as applicable, will use all reasonable
efforts to preserve intact their business organizations and assets and maintain
their rights, franchises and existing relations with customers, suppliers,
employees and business associates and to take no action that would:

             (i)   Adversely affect the ability of any of them to obtain any
                   necessary approvals of Governmental Entities required for the
                   transactions contemplated hereby;

             (ii)  Adversely affect its ability to perform its obligations under
                   this Agreement, the Bank Merger Agreement or the Option
                   Agreements; or

             (iii) Be reasonably likely to result in a Material Adverse Effect.

         (b) It will not:


                                       47
   50

             (i)   Sell or pledge or agree to sell or pledge or permit any Lien
                   to exist on any stock owned by it of any of the BancFirst
                   Subsidiaries or the UNB Subsidiaries, as applicable;

             (ii)  Amend its Articles of Incorporation or Code of Regulations or
                   By-laws;

             (iii) Split, combine or reclassify any outstanding capital stock;

             (iv)  Other than as permitted by Section 6.2, declare, set aside or
                   pay any dividend payable in cash, stock or other property
                   with respect to any of its capital stock; or

             (v)   Repurchase, redeem or otherwise acquire, or permit any
                   BancFirst Subsidiary or UNB Subsidiary to purchase or
                   otherwise acquire, directly or indirectly, any shares of its
                   capital stock or any securities convertible into or
                   exercisable for any shares of its capital stock.

         (c) Neither it nor any of the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, will:


             (i)   Issue, sell, pledge, dispose of or encumber, or authorize or
                   propose the issuance, sale, pledge, disposition or
                   encumbrance of, any shares of, or securities convertible or
                   exchangeable for, or options, warrants, calls, commitments or
                   rights of any kind to acquire, any shares of its capital
                   stock of any class, with the exception of BancFirst Shares or
                   UNB Shares issuable as of the date hereof pursuant to the
                   BancFirst Option Plan or UNB Plan I and UNB Plan II,
                   respectively, consistent with past practice, and the Option
                   Agreements;

             (ii)  Transfer, lease, license, guarantee, sell, mortgage, pledge
                   or dispose of any other material property or assets or
                   encumber any property or assets other than to a direct or
                   indirect wholly owned Subsidiary of it;

             (iii) Cancel, release, assign or modify any material amount of
                   indebtedness of any other individual, corporation or other
                   entity (collectively, a "Person") other than in the ordinary
                   and usual course of business; or

             (iv)  Authorize capital expenditures other than in the ordinary and
                   usual course of business.

         (d) Except as expressly contemplated in this Agreement and except for
internal reorganizations involving existing Subsidiaries, as applicable, neither
it nor any of the BancFirst Subsidiaries or the UNB Subsidiaries, as applicable,
will make any material


                                       48
   51

acquisition of, or investment in, assets or stock of any other Person not in the
ordinary and usual course of business.

         (e) Other than in the ordinary course of business consistent with past
practice, it will not incur or permit any of the BancFirst Subsidiaries or the
UNB Subsidiaries, as applicable, to incur any indebtedness for borrowed money or
assume, guarantee, endorse or otherwise as an accommodation become responsible
for the obligations of any other Person or make any loan or advance.

         (f) Except as required by agreements or arrangements Previously
Disclosed or as provided in Section 6.1(k) or as contemplated by Article II and
Section 7.7, neither it nor any of the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, will:

             (i)   Grant any increase in compensation or benefits to its
                   Employees or to its officers, except for normal increases
                   consistent with past practice or as required by law;

             (ii)  Pay any bonus except as consistent with past practice;

             (iii) Grant any severance or termination pay to any director,
                   officer or other of its Employees except as consistent with
                   past practice;

             (iv)  Enter into or amend any employment or severance agreement
                   with any director, officer or other of its Employees
                   (provided that this clause 6.1(f)(iv) shall not prohibit
                   either party from approving a renewal or other extension of
                   an existing employment or severance agreement in accordance
                   with its terms and in the ordinary course of business);

             (v)   Grant any increase in fees or other increases in compensation
                   or other benefits to any of its present or former directors;
                   or

             (vi)  Effect any change in retirement benefits for any class of its
                   Employees or officers (unless such change is required by
                   applicable law or, in the written opinion of counsel, is
                   necessary or advisable to maintain the tax qualification of
                   any plan under which the retirement benefits are provided).

         (g) Except as provided in Section 6.1(k) and as may be required to
satisfy contractual obligations existing as of the date hereof and the
requirements of applicable law, neither it nor any of the BancFirst Subsidiaries
or the UNB Subsidiaries, as applicable, will establish, adopt, enter into or
make any new, or amend any existing, collective bargaining, bonus, profit
sharing, thrift, compensation, stock option, restricted stock, pension,
retirement, employee stock ownership, deferred compensation, employment,
termination, severance or other plan, agreement, trust, fund, policy or
arrangement for the benefit of any directors, officers or employees.


                                       49
   52

         (h) Neither it nor any of the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, will implement or adopt any change in its
accounting principles, practices or methods, other than as may be required by
generally accepted accounting principles.

         (i) Neither it nor any of the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, shall make any tax election, other than in the
ordinary course of business.

         (j) Neither it nor any of the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, will authorize or enter into an agreement to take
any of the actions referred to in paragraphs 6.1(a) through 6.1(i) above.

         (k) Notwithstanding the provisions of Sections 6.1(f) and 6.1(g)
herein, each party hereto shall be permitted to take, or authorize or agree to
take, any of the actions contemplated in such Sections without the consent of
the other party, if such action:

             (i)   Is reasonably necessary to qualify for, or preserve, an
                   exemption of certain transactions from the operation of
                   Section 16(b) of the Exchange Act in accordance with the
                   provisions of SEC Rule 16b-3, as amended, or

             (ii)  Is Previously Disclosed.

    6.2  DIVIDENDS. After the date of this Agreement, each of BancFirst and UNB
shall coordinate with the other the declaration of any dividends in respect of
BancFirst Shares and UNB Shares and the record dates and payment dates relating
thereto, it being the intention of the parties hereto that holders of BancFirst
Shares or UNB Shares shall not receive two dividends, or fail to receive one
dividend, for any quarter with respect to their shares of BancFirst Shares
and/or UNB Shares and any Surviving Corporation Shares any such holder receives
in exchange therefor in the Merger.

    Unless BancFirst and UNB otherwise agree in writing, neither BancFirst
nor UNB will declare or pay any dividend or distribution on shares of their
capital stock, whether payable in cash, stock or other property, other than:

         (a) Dividends from Subsidiaries to BancFirst or UNB or to another
Subsidiary of BancFirst or UNB consistent with past practice; or (b) Regular
quarterly dividends or distributions, provided that:

             (i)   Such dividends or distributions, and their corresponding
                   record dates and payment dates, are coordinated between the
                   parties and are in the ordinary course consistent with past
                   practice; and

             (ii)  Such dividends or distributions are not in amounts exceeding
                   $.145 per quarter in the case of UNB and $.125 per quarter in
                   the case of BancFirst, subject to and consistent with each
                   party's normal practice for scheduled increases in the rate
                   of dividends paid on its common stock.


                                       50
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         6.3 ACQUISITION PROPOSALS; NO SOLICITATION.

             (a) Each of BancFirst and UNB ("Such Company") will immediately
cease all existing activities, discussions and negotiations with any parties
conducted heretofore with respect to any proposal for a Competing Transaction
and request the return of all confidential information regarding Such Company
provided to any such parties prior to the date hereof pursuant to the terms of
any confidentiality agreement or otherwise.

             (b) Such Company agrees that during the term of this Agreement it
will not, and will use its reasonable best efforts to ensure that its officers,
directors, employees, investment bankers, attorneys, accountants and other
agents and representatives do not, directly or indirectly:

                  (i)   Initiate, solicit or encourage, or take any action to
                        facilitate the making of, any offer or proposal which
                        constitutes or is reasonably likely to lead to any
                        Competing Transaction;

                  (ii)  Enter into any agreement with respect to any Competing
                        Transaction; or

                  (iii) In the event of an unsolicited written Competing
                        Transaction for Such Company, engage in negotiations or
                        discussions with, or provide any information or data
                        (except for information which has been previously
                        publicly disseminated by Such Company) to, any Person
                        relating to any Competing Transaction; provided,
                        however, that if at any time prior to the approval of
                        the Merger by the shareholders of Such Company, the
                        Board of Directors of Such Company determines in good
                        faith, after consultation with its outside counsel (who
                        may be its regularly engaged outside counsel) and its
                        financial advisors that it is necessary to do so in
                        order to act in a manner consistent with its fiduciary
                        duties to Such Company's shareholders under the OGCL,
                        Such Company may, in response to a Superior Proposal and
                        pursuant to a customary confidentiality agreement with
                        terms not substantially more favorable to such third
                        party than the Confidentiality Agreement, furnish
                        information to and negotiate or otherwise engage in
                        discussions with any third party who delivers a written
                        proposal for a superior proposal which was not
                        solicited, initiated, knowingly facilitated or
                        encouraged after the date of this Agreement.

             (c) In the event that prior to the approval of the Merger by the
Shareholders of Such Company:

                  (i)   The Board of Directors of Such Company receives a
                        Superior Proposal that was not solicited, initiated,
                        knowingly facilitated or encouraged after the date of
                        this Agreement (except as otherwise

                                       51
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                        permitted pursuant to the proviso contained in the first
                        sentence of Section 6.3(a)); and

                  (ii)  The Board of Directors of Such Company (subject to this
                        and the following sentences) determines in the exercise
                        of its fiduciary obligations under the OGCL in good
                        faith, after consultation with its outside counsel (who
                        may be its regularly engaged outside counsel) and its
                        financial advisors, to withdraw, modify or change, in a
                        manner adverse to the other of Such Companies not
                        receiving such proposal (the "Other Company"), the
                        recommendation of the Board of Directors of Such Company
                        of this Agreement or recommend a Superior Proposal to
                        the shareholders of Such Company, then the Board of
                        Directors of Such Company may provide such information
                        or access or engage in such discussions or negotiations
                        with respect to a Competing Transaction; provided,
                        however, that the foregoing shall in no way limit or
                        otherwise affect the Other Company's right to terminate
                        this Agreement pursuant to Section 9.1(f) at such time
                        as the requirements of such subsection have been met.
                        Any such withdrawal, modification or change in the
                        recommendation of the Board of Directors of Such Company
                        of this Agreement shall not change the approval of the
                        Board of Directors of Such Company for purposes of
                        causing any Anti-Takeover Statute or other state law to
                        be inapplicable to the Merger.

                  (iii) From and after the execution of this Agreement, Such
                        Company will notify the Other Company if any proposals
                        are received by, any information is requested from, or
                        any negotiations or discussions are sought to be
                        initiated or continued with Such Company or its
                        officers, directors, employees, investment bankers,
                        attorneys, accountants or other agents or
                        representatives, in each case in connection with any
                        Competing Transaction indicating, in connection with
                        such notice the name of the Person initiating such
                        Competing Transaction and the terms and conditions of
                        any proposals or offers. In addition, Such Company shall
                        notify the Other Company in writing, if the Board of
                        Directors of Such Company shall make any determination
                        as to a Competing Transaction as contemplated by the
                        provision to the first sentence of Section 6.3(a).

             (d) As used in this Agreement, "Competing Transaction" means any
proposal for a merger, consolidation or other business combination involving
either BancFirst or UNB, any proposal or offer to acquire in any manner a
substantial equity interest in, or a substantial portion of the business or
assets of, either BancFirst or UNB, any proposal or offer with respect to any
recapitalization or restructuring with respect to either BancFirst or UNB or any
proposal or offer with respect to any other transaction similar to any of the
foregoing with respect to either BancFirst or UNB, other than pursuant to the
Merger. As used in this Agreement, "Superior

                                       52
   55

Proposal" means a Competing Transaction regarding which the Board of Directors
of Such Company determines in good faith after consultation with its outside
counsel (who may be its regularly engaged outside counsel) and its financial
advisors that:

                  (i)   Is necessary for the Board of Directors of Such Company
                        to consider in order to act in a manner consistent with
                        its fiduciary duties to Such Company's shareholders
                        under the OGCL;

                  (ii)  Is more favorable to the shareholders of Such Company
                        than the Merger; and

                  (iii) It is reasonable to expect a transaction pursuant to
                        such proposal could be consummated.

             (e) Nothing contained in this Section 6.3. shall prohibit any Such
Company from taking and disclosing to its shareholders a position contemplated
by Rule 14e-2(a) promulgated under the Exchange Act.

                       ARTICLE VII ADDITIONAL AGREEMENTS

         7.1 REGULATORY MATTERS.

             (a) BancFirst and UNB shall promptly prepare and file with the SEC
the Joint Proxy Statement and UNB shall promptly prepare and file with the SEC
the Form S-4, in which the Joint Proxy Statement will be included as a
prospectus. BancFirst and UNB shall use all reasonable efforts to have the S-4
declared effective under the Securities Act as promptly as practicable after
such filing, and BancFirst and UNB shall thereafter mail or deliver the Joint
Proxy Statement to their respective shareholders. UNB shall also use all
reasonable efforts to obtain all necessary state securities law or "Blue Sky"
permits and approvals required to carry out the transactions contemplated by
this Agreement, and BancFirst shall furnish all information concerning BancFirst
and the holders of BancFirst Shares as may be reasonably requested in connection
with any such action.

             (b) The parties hereto shall cooperate with each other and use
their best efforts to promptly prepare and file all necessary documentation, to
effect all applications, notices, petitions and filings, to obtain as promptly
as practicable all permits, consents, approvals and authorizations of all third
parties and Governmental Entities which are necessary or advisable to consummate
the transactions contemplated by this Agreement and to comply with the terms and
conditions of all such permits, consents, approvals and authorizations of all
such Governmental Entities. BancFirst and UNB shall have the right to review in
advance, and to the extent practicable each will consult the other on, in each
case subject to applicable laws relating to the exchange of information, all the
information relating to BancFirst or UNB, as the case may be, and BancFirst
Bank, UNB Bank or any of the BancFirst Subsidiaries or the UNB Subsidiaries, as
applicable, which appear in any filing made with, or written materials submitted
to, any third party or any Governmental Entity in connection with the
transactions contemplated by this Agreement. In exercising the foregoing right,
each of the parties hereto shall act reasonably and as promptly as practicable.
The parties hereto agree that they will consult with each other with respect to
the obtaining of all permits, consents, approvals and authorizations of all
third parties

                                       53
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and Governmental Entities necessary or advisable to consummate the transactions
contemplated by this Agreement; and each party will keep the other apprised of
the status of matters relating to completion of the transactions contemplated
herein.

             (c) BancFirst and UNB shall, upon request, furnish each other with
all information concerning themselves, BancFirst Bank, UNB Bank, the BancFirst
Subsidiaries or the UNB Subsidiaries, as applicable, directors, officers and
shareholders and such other matters as may be reasonably necessary or advisable
in connection with the Joint Proxy Statement, the Form S-4 or any other
statement, filing, notice or application made by or on behalf of BancFirst, UNB,
BancFirst Bank, UNB Bank or any of the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, to any Governmental Entity in connection with the
Merger, the Bank Merger and the other transactions contemplated by this
Agreement.

             (d) BancFirst and UNB shall promptly advise each other upon
receiving any communication from any Governmental Entity whose consent or
approval is required for consummation of the transactions contemplated by this
Agreement which causes such party to believe that there is a reasonable
likelihood that any Requisite Regulatory Approval will not be obtained or that
the receipt of any such approval will be materially delayed.

         7.2 ACCESS TO INFORMATION.

             (a) Upon reasonable notice and subject to applicable laws relating
to the exchange of information, each of BancFirst and UNB, for the purposes of
verifying the representations and warranties of the other and preparing for the
Merger, the Bank Merger and the other matters contemplated by this Agreement,
shall, and shall cause each of BancFirst Bank, UNB Bank, the BancFirst
Subsidiaries or the UNB Subsidiaries, as applicable, to, afford to the officers,
employees, accountants, counsel and other representatives of the other party,
access, during normal business hours during the period prior to the Effective
Time, to all its properties, books, contracts, commitments and records; and
during such period each of BancFirst and UNB shall, and shall cause BancFirst
Bank, UNB Bank, the BancFirst Subsidiaries or the UNB Subsidiaries, as
applicable, to, make available to the other party:

                  (i)   A copy of each report, schedule, registration statement
                        and other document filed or received by it during such
                        period pursuant to the requirements of federal
                        securities laws or federal or state banking laws,
                        savings and loan or savings association laws (other than
                        reports or documents which BancFirst, BancFirst Bank,
                        UNB or UNB Bank, as the case may be, is not permitted to
                        disclose under applicable law); and

                  (ii)  All other information concerning its business,
                        properties and personnel as such party may reasonably
                        request.

             (b) Neither BancFirst, UNB, BancFirst Bank, UNB Bank, nor any of
the BancFirst Subsidiaries or the UNB Subsidiaries, as applicable, shall be
required to provide access to or to disclose information where such access or
disclosure would violate or prejudice the rights of BancFirst's or UNB's, as the
case may be, customers, jeopardize the attorney-client

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privilege of the institution in possession or control of such information or
contravene any law, rule, regulation, order, judgment, decree, fiduciary duty or
binding agreement entered into prior to the date of this Agreement. The parties
hereto will make appropriate substitute disclosure arrangements under
circumstances in which the restrictions of the preceding sentence apply.

             (c) Each of BancFirst and UNB shall hold all information furnished
by or on behalf of the other party or any of such party's Subsidiaries or
representatives pursuant to Section 7.2(a) in confidence the extent required by,
and in accordance with, the provisions of the confidentiality agreement, dated
June 27, 2001, between BancFirst and UNB (the "Confidentiality Agreement").

             (d) No investigation by either BancFirst or UNB or their respective
representatives shall affect the representations and warranties of the other set
forth herein.

         7.3 SHAREHOLDERS' APPROVALS. Each of BancFirst and UNB shall call a
meeting of its shareholders to be held as soon as reasonably practicable for the
purpose of voting upon the requisite shareholder approvals required in
connection with this Agreement and the Merger; and each shall use its best
efforts to cause such meetings to occur on the same date. The Board of Directors
of each of BancFirst and UNB shall recommend to its shareholders the approval of
the Merger, this Agreement and the transactions contemplated hereby.

         7.4 LEGAL CONDITIONS TO MERGER. Each of BancFirst and UNB shall, and
shall cause BancFirst Bank, UNB Bank, the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, to, use its best efforts:

             (a) To take, or cause to be taken, all actions necessary, proper or
advisable to comply promptly with all legal requirements which may be imposed on
such party or BancFirst Bank, UNB Bank, the BancFirst Subsidiaries or the UNB
Subsidiaries, as applicable, with respect to the Merger and the Bank Merger and,
subject to the conditions set forth in Article VIII hereof, to consummate the
transactions contemplated by this Agreement; and

             (b) To obtain (and to cooperate with the other party to obtain) any
consent, authorization, order or approval of, or any exemption by, any
Governmental Entity and any other third party which is required to be obtained
by UNB or BancFirst or any of BancFirst Bank, UNB Bank, the BancFirst
Subsidiaries or the UNB Subsidiaries, as applicable, in connection with the
Merger or the Bank Merger and the other transactions contemplated by this
Agreement, the Bank Merger Agreement or the Option Agreements.

         7.5 [INTENTIONALLY LEFT BLANK].

         7.6 NASDAQ QUOTATION. UNB shall cause the Surviving Corporation Shares
issued in the Merger to be authorized for quotation on NASDAQ, subject to
official notice of issuance, prior to the Effective Time.

         7.7 EMPLOYMENT AND COMPENSATION PROVISIONS. Following the Closing Date,
the Board of Directors of the Surviving Corporation shall use its best efforts
to resolve any material differences in terms and conditions of employment and
compensation, including but not limited to benefits, if any, payable because of
the occurrence of a Change of Control, taking into account

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that the Merger is to be a merger-of-equals transaction that treats each party's
directors and executive officers who are similarly situated on a substantially
equivalent basis, taking into account all relevant factors, including, without
limitation, duties, geographic location, tenure, qualifications and abilities,
and does not discriminate in favor of or against directors and executives solely
because they are directors or executives of one party and not the other. This
shall be accomplished as soon as reasonably practicable without impairing vested
rights or causing the Surviving Corporation to implement short-term arrangements
which are inconsistent with orderly development of a policy consistent with this
Section 7.7.

         7.8 EMPLOYEE BENEFIT PLANS; CERTAIN INSURANCE.

             (a) From and after the Effective Time, unless otherwise mutually
determined, the UNB Benefit Plans and BancFirst Benefit Plans in effect as of
the date of this Agreement shall remain in effect with respect to employees of
UNB or BancFirst (or BancFirst Bank, UNB Bank, the BancFirst Subsidiaries or the
UNB Subsidiaries, as applicable), respectively, covered by such plans at the
Effective Time until such time as the Surviving Corporation shall, subject to
applicable law, the terms of this Agreement and the terms of such plans, adopt
new benefit plans with respect to employees of the Surviving Corporation and its
Subsidiaries (the "New Benefit Plans"). Prior to the Closing Date, UNB and
BancFirst shall cooperate in reviewing, evaluating and analyzing the BancFirst
Benefit Plans and UNB Benefit Plans with a view toward developing appropriate
New Benefit Plans for the employees covered thereby subsequent to the Merger. It
is the intention of UNB and BancFirst to develop New Benefit Plans, as soon as
reasonably practicable after the Effective Time, which, among other things:

                  (i)   Treat similarly situated employees on a substantially
                        equivalent basis, taking into account all relevant
                        factors, including, without limitation, duties,
                        geographic location, tenure, qualifications and
                        abilities; and

                  (ii)  Do not discriminate between employees of the Surviving
                        Corporation who were covered by UNB Benefit Plans, on
                        the one hand, and those covered by BancFirst Benefit
                        Plans, on the other, at the Effective Time.

             (b) The foregoing notwithstanding, the Surviving Corporation agrees
to honor in accordance with their terms all benefits vested as of the date
hereof under the BancFirst Benefit Plans or the UNB Benefit Plans or under other
contracts, arrangements, commitments, or understandings described in the
BancFirst Disclosure Schedule and the UNB Disclosure Schedule.

             (c) Nothing in this Section 7.8 shall be interpreted as preventing
the Surviving Corporation from amending, modifying or terminating any BancFirst
Benefit Plans, UNB Benefit Plans, or other contracts, arrangements, commitments
or understandings, in accordance with their terms and applicable law.


             (d) From and after the Effective Time, the Surviving Corporation
shall purchase an extended reporting period endorsement ("Reporting Tail
Coverage") under

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BancFirst's and BancFirst Bank's existing directors' and officers' liability
insurance coverage for all persons who served as directors and officers of
BancFirst or BancFirst Bank or any of BancFirst Bank, UNB Bank, the BancFirst
Subsidiaries or the UNB Subsidiaries, as applicable, prior to the Effective Time
in a form acceptable to BancFirst (which acceptance shall not be unreasonably
withheld) which shall provide such directors and officers with coverage for six
years following the Effective Time of not less than the existing coverage under,
and have other terms not materially less favorable to the insured persons than,
the directors' and officers' liability insurance coverage presently maintained
by BancFirst and BancFirst Bank.

             (e) Certain additional agreements of BancFirst and UNB with respect
to compensation and benefits matters are set forth on Schedule 7.8(e) hereto.

         7.9 INDEMNIFICATION; DIRECTORS' AND OFFICERS' INSURANCE.

             (a) In the event of any threatened or actual claim, action, suit,
proceeding or investigation, whether civil, criminal or administrative,
including, without limitation, any such claim, action, suit, proceeding or
investigation in which any individual who is now, or has been at any time prior
to the date of this Agreement, or who becomes prior to the Effective Time, a
director or officer or employee of BancFirst, UNB, any of BancFirst Bank, UNB
Bank, the BancFirst Subsidiaries or the UNB Subsidiaries, as applicable,
including any entity specified in the BancFirst Disclosure Schedule or the UNB
Disclosure Schedule (the "Indemnified Parties"), is, or is threatened to be,
made a party based in whole or in part on, or arising in whole or in part out
of, or pertaining to:

                  (i)   The fact that he is or was a director, officer or
                        employee of BancFirst, UNB, any of BancFirst Bank, UNB
                        Bank, the BancFirst Subsidiaries or the UNB
                        Subsidiaries, or any entity specified in the BancFirst
                        Disclosure Schedule or the UNB Disclosure Schedule or
                        any of their respective predecessors; or

                  (ii)  This Agreement, the Option Agreements or any of the
                        transactions contemplated hereby or thereby,

whether in any case asserted or arising before or after the Effective Time, and
the parties hereto agree to cooperate and use their best efforts to defend
against and respond thereto.

             (b) It is understood and agreed that after the Effective Time, the
Surviving Corporation shall indemnify and hold harmless, as and to the fullest
extent permitted by law, each such Indemnified Party against any losses, claims,
damages, liabilities, costs, expenses (including reasonable attorney's fees and
expenses in advance of the final disposition of any claim, suit, proceeding or
investigation to each Indemnified Party to the fullest extent permitted by law
upon receipt of any undertaking required by applicable law), judgments, fines
and amounts paid in settlement in connection with any such threatened or actual
claim, action, suit, proceeding or investigation, and in the event of any such
threatened or actual claim, action, suit, proceeding or investigation (whether
asserted of arising before or after the Effective Time); and the Surviving
Corporation, after consultation with an Indemnified Party, shall retain counsel
and direct the defense thereof; provided, however, that by virtue of the
obligations herein set forth,

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the Surviving Corporation shall not be liable to any Indemnified Party for any
legal expenses of other counsel or any other expenses incurred by any
Indemnified Party in connection with the defense thereof, except that, if the
Surviving Corporation fails or elects not to assume such defense or counsel for
the Indemnified Parties reasonably advises the Indemnified Parties that there
are issues which raise conflicts of interest between the Surviving Corporation
and the Indemnified Parties,

                  (i)   The Indemnified Parties may retain counsel reasonably
                        satisfactory to them after consultation with the
                        Surviving Corporation, and the Surviving Corporation
                        shall pay the reasonable fees and expenses of such
                        counsel for the Indemnified Parties;

                  (ii)  The Surviving Corporation shall be obligated pursuant to
                        this paragraph to pay for only one firm of counsel for
                        all Indemnified Parties, unless an Indemnified Party
                        shall have reasonably concluded, based on the advice of
                        counsel and after consultation with the Surviving
                        Corporation, that in order to be adequately represented,
                        separate counsel is necessary for such Indemnified
                        Party, in which case, the Surviving Corporation shall be
                        obligated to pay for such separate counsel;

                  (iii) The Surviving Corporation shall not be liable for any
                        settlement effected without its prior written consent
                        (which consent shall not be unreasonably withheld); and

                  (iv)  The Surviving Corporation shall have no obligation
                        hereunder to any Indemnified Party when and if a court
                        of competent jurisdiction shall ultimately determine,
                        and such determination shall have become final and
                        nonappealable, that indemnification of such Indemnified
                        Party in the manner contemplated hereby is prohibited by
                        applicable law. Any Indemnified Party wishing to claim
                        indemnification under this Section 7.9, upon learning of
                        any such claim, action, suit, proceeding or
                        investigation, shall notify the Surviving Corporation
                        thereof, provided that the failure to so notify shall
                        not affect the obligations of the Surviving Corporation
                        under this Section 7.9 except to the extent such failure
                        to notify materially prejudices the Surviving
                        Corporation. The Surviving Corporation's obligations
                        under this Section 7.9 continue in full force and effect
                        for a period of six years from the Effective Time (or
                        the period of the applicable statute of limitations, if
                        longer); provided, however, that all rights to
                        indemnification in respect of any claim (a "Claim")
                        asserted or made within such period shall continue until
                        the final disposition of such Claim.

             (c) BancFirst (and the Surviving Corporation, from and after the
Effective Time) shall use its best efforts to cause the individuals serving as
officers and directors of BancFirst, BancFirst Bank, the BancFirst Subsidiaries
or any entity specified in the BancFirst

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Disclosure Schedule immediately prior to the Effective Time to be covered for a
period of six (6) years from the Effective Time (or the period of the applicable
statute of limitations, if longer) by the directors' and officers' liability
insurance policy maintained by BancFirst (provided that the Surviving
Corporation may substitute therefor policies of at least the same coverage and
amounts containing terms and conditions which are not less advantageous than
such policy) with respect to acts or omissions occurring prior to the Effective
Time which were committed by such officers and directors in their capacity as
such; provided, however, that in no event shall the Surviving Corporation be
required to expend more than three hundred percent (300%) of the current amount
expended by BancFirst (the "Insurance Amount") to maintain or procure insurance
coverage pursuant hereto and provided further that if the Surviving Corporation
is unable to maintain or obtain the insurance called for by this Section 7.9(b),
the Surviving Corporation shall use its best efforts to obtain as much
comparable insurance as available for the Insurance Amount.

             (d) In the event the Surviving Corporation or any of its successors
or assigns:

                  (i)   Consolidates with or merges into any other person and
                        shall not be the continuing or Surviving Corporation or
                        entity of such consolidation or merger; or

                  (ii)  Transfers or conveys all or substantially all of its
                        properties and assets to any Person,

then, and in each such case, to the extent necessary, proper provision shall be
made so that the successors and assigns of the Surviving Corporation assume the
obligations set forth in this section.

             (e) The provisions of this Section 7.9 are intended to be for the
benefit of, and shall be enforceable by, each Indemnified Party and his or her
heirs and representatives.

         7.10 ADDITIONAL AGREEMENTS. In case at any time after the Effective
Time any further action is necessary or desirable to carry out the purposes of
this Agreement (including, without limitation, the Bank Merger or any other
merger between a Subsidiary of UNB, on the one hand, and a Subsidiary of
BancFirst on the other) or to vest the Surviving Corporation with full title to
all properties, assets, rights, approvals, immunities and franchises of any of
the parties to the Merger, the proper officers and directors of each party to
this Agreement and the BancFirst Subsidiaries or the UNB Subsidiaries, as
applicable, shall take all such necessary action as may be reasonably requested
by, and at the sole expense of, the Surviving Corporation.

         7.11 ADVICE OF CHANGES. BancFirst and UNB shall each promptly advise
the other party of any change or event:

             (a) Having a Material Adverse Effect on it; or

             (b) Which it believes would or would be reasonably likely to cause
or constitute a material breach of any of its representations, warranties or
covenants contained herein.

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                     ARTICLE VIII CONDITIONS PRECEDENT

         8.1 CONDITIONS TO EACH PARTY'S OBLIGATION TO EFFECT THE MERGER. The
respective obligations of the parties to effect the Merger shall be subject to
the satisfaction at or prior to the Effective Time of the following conditions:

             (a) SHAREHOLDER APPROVAL. This Agreement and the transactions
contemplated hereby shall have been approved and adopted by the respective
requisite affirmative votes of the holders of UNB Shares and BancFirst Shares
entitled to vote thereon.

             (b) NASDAQ QUOTATION. The Surviving Corporation's Shares which
shall be issued to the shareholders of BancFirst upon consummation of the Merger
shall have been authorized for quotation on NASDAQ as contemplated by Section
7.6, subject to official notice of issuance.

             (c) OTHER APPROVALS. All regulatory approvals required to
consummate the transactions contemplated hereby shall have been obtained and
shall remain in full force and effect and all statutory waiting periods in
respect thereof shall have expired (all such approvals and the expiration of all
such waiting periods being referred to herein as the "Requisite Regulatory
Approvals").

             (d) FORM S-4 REGISTRATION STATEMENT. The Form S-4 Registration
Statement for filing with the SEC under the Securities Act shall have become
effective under the Securities Act and no stop order suspending the
effectiveness of the Form S-4 shall have been issued and no proceedings for that
purpose shall have been initiated or threatened by the SEC.

             (e) NO INJUNCTIONS OR RESTRAINTS; ILLEGALITY. No order, injunction
or decree issued by any court or agency of competent jurisdiction or other legal
restraint or prohibition (an "Injunction") preventing the consummation of the
Merger, the Bank Merger or any of the other transactions contemplated by this
Agreement shall be in effect. No statute, rule, regulation, order, injunction or
decree shall have been enacted, entered, promulgated or enforced by any
Governmental Entity which prohibits, materially restricts or makes illegal
consummation of the Merger or the Bank Merger.

             (f) FEDERAL TAX OPINION. UNB shall have received an opinion of
Black, McCuskey, Souers & Arbaugh, in form and substance reasonably satisfactory
to UNB and BancFirst shall have received an opinion of Bricker & Eckler LLP in
form and substance reasonably satisfactory to BancFirst, in each case and dated
the Closing Date, substantially to the effect that, on the basis of facts,
representations and assumptions set forth in such opinion which are consistent
with the state of facts existing at the Effective Time:

                  (i)   The Merger will constitute a reorganization under
                        Section 368(a) of the Code; BancFirst and UNB will each
                        be a party to the reorganization in respect of the
                        Merger;

                  (ii)  No gain or loss will be recognized by BancFirst or UNB
                        as a result of the Merger; and

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   63

                  (iii) No gain or loss will be recognized by shareholders of
                        BancFirst who receive solely UNB Shares for their
                        BancFirst Shares pursuant to the Merger.

In rendering such opinion, counsel may require and rely upon representations
contained in certificates of officers of BancFirst, UNB and others.

         8.2 CONDITIONS TO OBLIGATIONS OF BANCFIRST. The obligations of
BancFirst to effect the Merger are also subject to the satisfaction or waiver by
BancFirst, at or prior to the Effective Time, of the following conditions:

             (a) REPRESENTATIONS AND WARRANTIES. The representations and
warranties of UNB and UNB Bank set forth in this Agreement shall be true and
correct in all material respects as of the date of this Agreement and (except to
the extent such representations and warranties speak as of an earlier date) as
of the Closing Date as though made on and as of the Closing Date; provided,
however, that for purposes of this paragraph, such representations and
warranties shall be deemed to be true and correct unless the failure or failures
of such representations and warranties to be so true and correct, individually
or in the aggregate, and without giving effect to any qualification as to
materiality set forth in such representations or warranties, would have a
Material Adverse Effect on UNB. BancFirst shall have received a certificate
signed on behalf of UNB by the Chief Executive Officer and the Chief Financial
Officer of UNB to the foregoing effect.

             (b) PERFORMANCE OF OBLIGATIONS OF UNB. UNB shall have performed in
all material respects all obligations required to be performed by it under this
Agreement at or prior to the Closing Date, and BancFirst shall have received a
certificate signed on behalf of UNB by the Chief Executive Officer and the Chief
Financial Officer of UNB to such effect.

         8.3 CONDITIONS TO OBLIGATIONS OF UNB. The obligation of UNB to effect
the Merger is also subject to the satisfaction or waiver by UNB at or prior to
the Effective Time of the following conditions:

             (a) REPRESENTATIONS AND WARRANTIES. The representations and
warranties of BancFirst and BancFirst Bank set forth in this Agreement shall be
true and correct in all material respects as of the date of this Agreement and
(except to the extent such representations and warranties speak as of an earlier
date) as of the Closing Date as though made on and as of the Closing Date;
provided, however, that for purposes of this paragraph, such representations and
warranties shall be deemed to be true and correct unless the failure or failures
of such representations and warranties to be so true and correct, individually
or in the aggregate, and without giving effect to any qualification as to
materiality set forth in such representations or warranties, would have a
Material Adverse Effect on BancFirst. UNB shall have received a certificate
signed on behalf of BancFirst by the Chief Executive Officer and the Chief
Financial Officer of BancFirst to the foregoing effect.

             (b) PERFORMANCE OF OBLIGATIONS OF BANCFIRST. BancFirst shall have
performed in all material respects all obligations required to be performed by
it under this Agreement at or prior to the Closing Date, and UNB shall have
received a certificate signed on behalf of

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BancFirst by the Chief Executive Officer and the Chief Financial Officer of
BancFirst to such effect.

                      ARTICLE IX TERMINATION AND AMENDMENT

         9.1 TERMINATION. This Agreement may be terminated at any time prior to
the Effective Time, whether before or after approval of the matters presented in
connection with the Merger by the shareholders of BancFirst or UNB:

             (a) By mutual consent of BancFirst and UNB in a written instrument,
if the Board of Directors of each so determines by a vote of a majority of the
members of its entire Board;

             (b) By either the Board of Directors of BancFirst or the Board of
Directors of UNB if any Governmental Entity which must grant a Requisite
Regulatory Approval has denied approval of the Merger or any Governmental Entity
of competent jurisdiction shall have issued an order permanently enjoining or
otherwise prohibiting the consummation of the transactions contemplated by this
Agreement;

             (c) By either the Board of Directors of BancFirst or the Board of
Directors of UNB if the Merger shall not have been consummated on or before
September 30, 2002, unless the failure of the Closing to occur by such date
shall be due to the failure of the party seeking to terminate this Agreement to
perform or observe the covenants and agreements of such party set forth herein;

             (d) By either the Board of Directors of BancFirst or the Board of
Directors of UNB (provided that the terminating party is not then in breach of
any representation, warranty, covenant or other agreement contained herein) if
there shall have been a breach of any of the covenants or agreements or any of
the representations or warranties set forth in this Agreement on the part of
UNB, in the case of a termination by BancFirst or, on the part of BancFirst, in
the case of a termination by UNB, which breach, individually or together with
other such breaches, would constitute, if occurring or continuing on the Closing
Date, the failure of the conditions set forth in Section 8.2 or 8.3, as the case
may be, and which is not cured within forty-five (45) days following written
notice to the party committing such breach or by its nature or timing cannot be
cured prior to the Closing Date; or

             (e) By either BancFirst or UNB if any approval of the shareholders
of BancFirst or UNB required for the consummation of the Merger shall not have
been obtained by reason of the failure to obtain the required vote at a duly
held meeting of shareholders or at any adjournment or postponement thereof.

             (f) By either BancFirst or UNB if the Other Company makes the
determination described in Section 6.3(c)(ii).

         9.2 EFFECT OF TERMINATION. In the event of termination of this
Agreement by either BancFirst or UNB as provided in Section 9.1, this Agreement
shall forthwith become void and have no effect, and none of BancFirst, UNB, any
of their respective Subsidiaries or any of the

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officers or directors of any of them shall have any liability of any nature
whatsoever hereunder, or in connection with the transactions contemplated
hereby, except that:

                  (i)   Sections 7.2(c) 9.2 and 10.3 shall survive any
                        termination of this Agreement,

                  (ii)  The Option Agreements remain in full force and effect
                        until terminated as provided therein; and

                  (iii) Notwithstanding anything to the contrary contained in
                        this Agreement, neither BancFirst nor UNB shall be
                        relieved or released from any liabilities or damages
                        arising out of its willful breach of any provision of
                        this Agreement.

         9.3 AMENDMENT. Subject to compliance with applicable law, this
Agreement may be amended by the parties hereto, by action taken or authorized by
their respective Boards of Directors, at any time before or after approval of
the matters presented in connection with the Merger by the shareholders of
BancFirst and UNB; provided, however, that after any approval of the
transactions contemplated by this Agreement by the respective shareholders of
BancFirst or UNB, there may not be, without further approval of such
shareholders, any amendment of this Agreement which changes the amount or the
form of the consideration to be delivered hereunder to the holders of UNB
Shares, or into which BancFirst Shares shall be converted pursuant to the
Merger, other than as contemplated by this Agreement. This Agreement may not be
amended except by an instrument in writing signed on behalf of each of the
parties hereto.

         9.4 EXTENSION; WAIVER. At any time prior to the Effective Time, the
parties hereto, by action taken or authorized by their respective Board of
Directors, may, to the extent legally allowed:

             (a) Extend the time for the performance of any of the obligations
or other acts of the other parties hereto;

             (b) Waive any inaccuracies in the representations and warranties
contained herein or in any document delivered pursuant hereto; and

             (c) Waive compliance with any of the agreements or conditions
contained herein; provided, however, that after any approval of the transactions
contemplated by this Agreement by the respective shareholders of BancFirst or
UNB, there may not be, without further approval of such shareholders, any
extension or waiver of this Agreement or any portion thereof which reduces the
amount or changes the form of the consideration to be delivered to the holders
of BancFirst Shares hereunder, or into which BancFirst Shares shall be converted
pursuant to the Merger, other than as contemplated by this Agreement. Any
agreement on the part of a party hereto to any such extension or waiver shall be
valid only if set forth in a written instrument signed on behalf of such party,
but such extension or waiver or failure to insist on strict compliance with an
obligation, covenant, agreement or condition shall not operate as a waiver of,
or estoppel with respect to, any subsequent or other failure.

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                          ARTICLE X GENERAL PROVISIONS

         10.1 CLOSING. Subject to the terms and conditions of this Agreement and
the Option Agreements, the Closing will take place at 10:00 a.m. on the date
specified in Section 1.4 (the "Closing Date") and at a place to be specified by
the parties.

         10.2 NONSURVIVAL OF REPRESENTATIONS, WARRANTIES AND AGREEMENTS. None of
the representations, warranties, covenants and agreements in this Agreement or
in any instrument delivered pursuant to this Agreement (other than the Option
Agreements and the Confidentiality Agreement, which shall each terminate in
accordance with its terms) shall survive the Effective Time, except for those
covenants and agreements contained herein and therein which by their terms apply
in whole or in part after the Effective Time.

         10.3 EXPENSES.

             (a) All costs and expenses incurred in connection with this
Agreement and the transactions contemplated hereby shall be paid by the party
incurring such expense; provided, however, that the costs and expenses of
printing and mailing the Joint Proxy Statement, and all filing and other fees
paid to the SEC in connection with the Merger, shall be borne equally by
BancFirst and UNB.

             (b) Notwithstanding the provisions of Section 10.3(a), in the event
that BancFirst or UNB makes the determination described in Section 6.3(c)(ii),
then Such Company shall within ten (10) days pay to the Other Company the sum of
$1,000,000 as liquidated damages.

         10.4 NOTICES. All notices and other communications hereunder shall be
in writing and shall be deemed given if delivered personally, telecopied (with
confirmation), mailed by registered or certified mail (return receipt requested)
or delivered by an express courier (with confirmation) to the parties at the
following addresses (or at such other address for a party as shall be specified
by like notice):

             (a) If to BancFirst:

                   BancFirst Ohio Corp.
                   422 Main Street
                   P.O. Box 4658
                   Zanesville, OH 43702-46588
                   Attention:  Gary N. Fields

                  With a copy to:

                   Michael F. Sullivan, Esq.
                   Bricker & Eckler LLP
                   100 South Third Street
                   Columbus, Ohio 43215-4291

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             (b) If to UNB:

                    UNB Corp.
                    220 Market Avenue South
                    Canton, Ohio  44701
                    Attention:  Roger L. Mann

                   With a copy to:

                    Ronald K. Bennington, Esq.
                    Black, McCuskey, Souers & Arbaugh
                    1000 United Bank Plaza
                    220 Market Avenue South
                    Canton, Ohio  44702-2116

         10.5 INTERPRETATION. When a reference is made in this Agreement to
Sections, Exhibits or Schedules, such reference shall be to a Section of or
Exhibit or Schedule to this Agreement unless otherwise indicated. The table of
contents and headings contained in this Agreement are for reference purposes
only and shall not affect in any way the meaning or interpretation of this
Agreement. Whenever the words "include," "includes" or "including" are used in
this Agreement, they shall be deemed to be followed by the words "without
limitation." No provision of this Agreement shall be construed to require UNB,
BancFirst or any of BancFirst Bank, UNB Bank, the BancFirst Subsidiaries or the
UNB Subsidiaries, as applicable, or affiliates to take any action which would
violate any applicable law, rule or regulation.

         10.6 COUNTERPARTS. This Agreement may be executed in counterparts, all
of which shall be considered one and the same agreement and shall become
effective when counterparts have been signed by each of the parties and
delivered to the other parties, it being understood that all parties need not
sign the same counterpart.

         10.7 ENTIRE AGREEMENT. This Agreement (including the documents and the
instruments referred to herein) constitutes the entire agreement and supersedes
all prior agreements and understandings, both written and oral, among the
parties with respect to the subject matter hereof other than the Bank Merger
Agreement, Option Agreements and the Confidentiality Agreement.

         10.8 GOVERNING LAW. This Agreement shall be governed and construed in
accordance with the laws of the State of Ohio, without regard to any applicable
conflicts of law (except to the extent that mandatory provisions of federal law
or of the OGCL are applicable).

         10.9 SEVERABILITY. Any term or provision of this Agreement which is
invalid or unenforceable in any jurisdiction shall, as to that jurisdiction, be
ineffective to the extent of such invalidity or unenforceability without
rendering invalid or unenforceable the remaining terms and provisions of this
Agreement or affecting the validity or enforceability of any of the terms or
provisions of this Agreement in any other jurisdiction. If any provision of this
Agreement is so broad as to be unenforceable, the provision shall be interpreted
to be only so broad as is enforceable.

                                       65
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         10.10 PUBLICITY. Except as otherwise required by applicable law,
neither of BancFirst nor UNB shall, or shall permit any of its Subsidiaries to,
issue or cause the publication of any press release or other public announcement
with respect to, or otherwise make any public statement concerning, the
transactions contemplated by this Agreement without the consent of UNB, in the
case of a proposed announcement or statement by BancFirst, or without the
consent of BancFirst, in the case of a proposed announcement or statement by
UNB, which consent shall not be unreasonably withheld.

         10.11 ASSIGNMENT; THIRD PARTY BENEFICIARIES. Neither this Agreement nor
any of the rights, interests or obligations shall be assigned by any of the
parties hereto (whether by operation of law or otherwise) without the prior
written consent of the other parties. Subject to the preceding sentence, this
Agreement will be binding upon, inure to the benefit of and be enforceable by
the parties and their respective successors and assigns. Except as otherwise
specifically provided in Article II and Section 7.7, this Agreement (including
the documents and instruments referred to herein) is not intended to confer upon
any person other than the parties hereto any rights or remedies hereunder.


                                       66

   69

         IN WITNESS WHEREOF, BancFirst, BancFirst Bank, UNB and UNB Bank have
caused this Agreement to be executed by their respective officers thereunto duly
authorized as of the date first above written.

                               UNB CORP

                               By:     /s/ Roger L. Mann
                                       ---------------------------------------

                               Its:    Chairman and CEO
                                       ---------------------------------------



                               THE UNITED NATIONAL BANK & TRUST COMPANY



                               By:     /s/ Roger L. Mann
                                       ---------------------------------------

                               Its:    Chairman and CEO
                                       ---------------------------------------



                               BANCFIRST OHIO CORP.



                               By:     /s/ Gary N. Fields
                                       ---------------------------------------

                               Its:    President and CEO
                                       ---------------------------------------



                               THE FIRST NATIONAL BANK OF ZANESVILLE, N.A.



                               By:     /s/ James H. Nicholson
                                       ---------------------------------------

                               Its:    President and CEO
                                       ---------------------------------------

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                                     ANNEX A

DEFINED TERMS

"Agreement" is defined in the Preamble.

"Anti-Takeover Statute" shall mean any of OGCL Section 1701.831, Chapter 1704 or
      Section 1707.043, or any other provision in the OGCL that delays or
      prevents unsolicited third party takeover attempts.

"Awarded Bonus Plan Shares" is defined in Section 4.8(a)(ii).

"BancFirst" is defined in the Preamble.

"BancFirst Audited Financials" is defined in Section 4.9(a).

"BancFirst Bank" is defined in the Preamble.

"BancFirst Benefit Plans" is defined in Section 4.20(a).

"BancFirst Consolidated Statements" is defined in Section 4.9(c).

"BancFirst Contracts" is defined in Section 4.16(a)(xii).

"BancFirst Disclosure Schedule" is defined in the preamble to Article IV.

"BancFirst Interim Financials" is defined in Section 4.9(b).

"BancFirst Investments" is defined in Section 4.13(a).

"BancFirst Leased Real Property" is defined in Section 4.11(c).

"BancFirst Loan Assets" is defined in Section 4.11(e).

"BancFirst Loan Documentation" is defined in Section 4.11(e).

"BancFirst Option Plan" is defined in Section 1.3(a).

"BancFirst Parcel" is defined in Section 4.11(b).

"BancFirst Personal Property" is defined in Section 4.11(a).

"BancFirst Property" is defined in Section 4.21(b)(i).

"BancFirst Real Properties" is defined in Section 4.11(b).

                                   ANNEX A-1
   71


"BancFirst SEC Filings" is defined in Section 4.14(b).

"BancFirst Shares" is defined in Section 1.2.

"BancFirst Subsidiaries" is defined in Section 4.2(a).

"Bank Merger" is defined in the Recitals.

"Bank Merger Agreement" is defined in Section 1.1(b).

"BHCA" is defined in Section 4.1(a).

"BIF" is defined in Section 4.1(b).

"Bonus Plan" is defined in Section 4.8(a)(ii).

"Capital Trust" is defined in Section 4.2(a).

"Certificates" is defined in Section 3.1(a).

"Chornyak" is defined in Section 4.2(a).

"Claim" is defined in Section 7.9(b)(iv).

"Closing" is defined in Section 1.4.

"Closing Date" is defined in Section 10.1.

"Code" is defined in Section 1.6.

"Competing Transaction" is defined in Section 6.3(d).

"Confidentiality Agreement" is defined in Section 7.2(c).

"Disqualified Individual" is defined in Section 4.15(c).

"Dissenting Shareholder" is defined in Section 3.4(a).

"Effective Time" is defined in Section 1.4.

"Employees" shall mean current or former employees, directors or independent
      contractors (and their spouses, dependents or beneficiaries) of BancFirst,
      UNB or their Subsidiaries.

"Environmental Laws" is defined in Section 4.21(b)(ii).

"ERISA" is defined in Section 4.20(a).

                                   ANNEX A-2
   72

"ExchangeAct" shall mean the Securities Exchange Act of 1934, as amended
      (including the rules and regulations thereunder).

"FDIC" shall mean the Federal Deposit Insurance Corporation.

"FHLB" shall mean Federal Home Loan Bank.

"Former BancFirst Directors" is defined in Section 2.2(a).

"Former UNB Directors" is defined in Section 2.2(a).

"Form S-4" shall mean the registration statement to be filed with the SEC in
      connection with the issuance of Surviving Corporation Shares.

"FRB" is defined in Section 4.6(e).

"Governing Documents" shall mean the Articles of Incorporation, Articles of
      Association, Code of Regulations or Bylaws of an entity.

"Governmental Entity" shall mean any governmental or regulatory authority,
      agency, court, commission or other entity, domestic or foreign.

"Hazardous Substances" is defined in Section 4.21(b)(iii).

"Indemnified Parties" is defined in Section 7.9(a).

"Injunction" is defined in Section 8.1(e).

"Insurance Amount" is defined in Section 7.9(c).

"IRS" shall mean the Internal Revenue Service.

"Joint Proxy Statement" shall mean the joint proxy statement and prospectus and
      other proxy solicitation materials of BancFirst and UNB constituting a
      part of the Form S-4.

"Lien" shall include any lien, pledge, security interest, claim, proxy,
      preemptive or subscriptive right or other encumbrance or restriction of
      any kind.

"Material Adverse Effect" shall mean with respect to BancFirst, UNB or the
      Surviving Corporation any effect that (1) is material and adverse to the
      financial position, results of operations or business of BancFirst and its
      Subsidiaries taken as a whole, UNB and its Subsidiaries taken as a whole
      or the Surviving Corporation and its Subsidiaries taken as a whole,
      respectively, or (2) would materially impair the ability of either
      BancFirst or UNB to perform its obligations under this Agreement or
      otherwise materially threaten or

                                   ANNEX A-3
   73

      materially impede the consummation of the Merger and the other
      transactions contemplated by this Agreement; provided, however, that
      Material Adverse Effect shall not be deemed to include the impact of (A)
      changes in banking and similar laws of general applicability or
      interpretations thereof by courts or governmental authorities, (B) changes
      in generally accepted accounting principles or regulatory accounting
      requirements applicable to depository institutions and their holding
      companies generally, (C) actions or omissions of BancFirst or UNB taken
      with the prior written consent of UNB or BancFirst, as applicable, in
      contemplation of the transactions contemplated hereby, (D) any
      modifications or changes to valuation policies and practices in connection
      with the Merger or restructuring charges taken in connection with the
      Merger, in each case in accordance with generally accepted accounting
      principles and (E) the effects of any change attributable to or resulting
      from changes in economic conditions applicable to depository institutions
      or their holding companies generally or in general levels of interest
      rates, except to the extent that the effect of such change is materially
      more severe for BancFirst, UNB or the Surviving Corporation, as the case
      may be, than for depository institutions or their holding companies
      generally.

"Merger" is defined in the Recitals.

"NASDAQ" is defined in Section 1.2(a)(ii).

"NBA" is defined in Section 4.1(b).

"New Benefit Plans" is defined in Section 7.8(a).

"Nominating Committee" is defined in Section 2.2(c)(i).

"OCC" shall mean the Office of the Comptroller of the Currency.

"OGCL" is defined in Section 1.1(a).

"Option Agreements" is defined in the Recitals.

"ORC" shall mean the Ohio Revised Code.

"Other Company" is defined in Section 6.3(c)(ii).

"OTS" shall mean the Office of Thrift Supervision.

"PBGC" is defined in Section 4.20(f).

"Per Share Merger Consideration" is defined in Section 1.2(a).

"Person" is defined in Section 6.1(c)(iii).

                                   ANNEX A-4
   74

"Previously Disclosed" by a party shall mean information set forth on its
      Disclosure Schedule corresponding to the provision of this Agreement to
      which such information relates; provided that information which, on its
      face, reasonably should indicate to the reader that it relates to another
      provision of this Agreement shall also be deemed to be Previously
      Disclosed with respect to such other provision.

"Real Property Leases" shall mean all leases for BancFirst or UNB Leased Real
      Property.

"Regulatory Agreement" is defined in Section 4.25.

"Regulatory Applications" shall mean such applications, notices or other
      instruments as may be required for approval of the Merger.

"Reporting Tail Coverage" is defined in Section 7.8(d).

"Requisite Regulatory Approvals" is defined in Section 8.1(c).

"SEC" shall mean the Securities and Exchange Commission.

"Securities Act" shall mean the Securities Act of 1933, as amended (including
      the rules and regulations thereunder).

"Special Majority" is defined in Section 2.4(a).

"Subsidiary" shall mean UNB Bank or BancFirst Bank or any other organization or
      entity which is consolidated or is eligible to be consolidated with a
      party to this Agreement for financial reporting purposes.

"Such Company" is defined in Section 6.3(a).

"Superior Proposal" is defined in Section 6.3(d).

"Surviving Bank" shall mean the surviving bank of the Bank Merger.

"Surviving Corporation" is defined in Section 1.1(a).

"Termination Date" is defined in Section 2.1.

"Title Agency" is defined in Section 4.2(a).

"Transmittal Letter" is defined in Section 3.1(a).

"Trust Company" is defined in Section 4.2(a).

"UNB" is defined in the Preamble.

"UNB Audited Financials" is defined in Section 5.9(a).

"UNB Bank" is defined in the Preamble.

                                   ANNEX A-5
   75

"UNB Benefit Plans" is defined in Section 5.20(a).

"UNB Consolidated Statements" is defined in Section 5.9(c).

"UNB Contracts" is defined in Section 5.16(a)(xii).

"UNB Disclosure Schedule" is defined in preamble to Article V.

"UNB Interim Financials" is defined in Section 5.9(b).

"UNB Investments" is defined in Section 5.13(a).

"UNB Leased Real Property" is defined in Section 5.11(c).

"UNB Loan Assets" is defined in Section 5.11(e).

"UNB Loan Documentation" is defined in Section 5.11(e).

"UNB Market Value" is defined in Section 1.2(a)(ii).

"UNB Plan I" is defined in Section 1.3.

"UNB Plan II" is defined in Section 1.3.

"UNB Parcel" is defined in Section 5.11(b).

"UNB Personal Property" is defined in Section 5.11(a).

"UNB Property" is defined in Section 5.21(b).

"UNB Real Properties" is defined in Section 5.11(b).

"UNB SEC Filings" is defined in Section 5.14(b).

"UNB Shares" is defined in Section 1.2(a).

"UNB Subsidiaries" is defined in Section 5.2(a).

"Unvested Bonus Plan Shares" is defined in Section 4.8(a)(ii).

                                   ANNEX A-6