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                                                                    Exhibit 99.2



                             STOCK OPTION AGREEMENT


         Stock Option Agreement, dated as of September 5, 2001, (the
"Agreement"), between BancFirst Ohio Corporation, an Ohio corporation
("Issuer"), and UNB Corp., an Ohio corporation ("Grantee").

                                   WITNESSETH:

         WHEREAS, Issuer and Grantee have entered into an Agreement of Merger
and Plan of Reorganization, dated as of September 5, 2001 (the "Plan"),
providing for, among other things, the merger of Issuer with and into Grantee
(the "Merger"), with Grantee as the surviving corporation; and

         WHEREAS, as a condition and inducement to Grantee's execution of the
Plan, Grantee has required that Issuer agree, and Issuer has agreed, to grant to
Grantee the Option (as hereinafter defined);

         NOW THEREFORE, in consideration of the foregoing and the respective
representations, warranties, covenants and agreements set forth herein and in
the Plan, and intending to be legally bound hereby, Issuer and Grantee agree as
follows:

         1. DEFINED TERMS. Capitalized terms which are used but not defined
herein shall have the meanings ascribed to such terms in the Plan.

         2. GRANT OF OPTION. Subject to the terms and conditions set forth
herein, Issuer hereby grants to Grantee an irrevocable option (the "Option") to
purchase up to 1,302,533 shares (as adjusted as set forth herein) (the "Option
Shares," which shall include the Option Shares before and after any transfer of
such Option Shares) of Common Stock, without par value ("Issuer Common Stock"),
of Issuer at a purchase price per Option Share (as adjusted as set forth
herein, the "Purchase Price") of $20.95, provided, however, that in no event
shall the number of Option Shares for which the Option may be exercisable, when
added to aggregate of all Issuer voting securities (as hereinafter defined) in
respect of which the Grantee and each Holder (as hereinafter defined) may then
exercise or direct the exercise of voting power in the election of Issuer's
directors, exceed 19.9% of the aggregate such voting power then exercisable by
the holders of all Issuer voting securities then issued and outstanding as
determined without giving effect to any shares subject to or issued pursuant to
the Option.

         3. EXERCISE OF OPTION.

         (a) Provided that:

             (i) Grantee or Holder (as hereinafter defined), as applicable,
         shall not be in material breach of the agreements or covenants
         contained in this Agreement or the Plan; and (ii) No preliminary or
         permanent injunction or other order against the delivery of shares
         covered by the Option issued by any court of competent jurisdiction in
         the United States shall be in effect, Holder may exercise the Option,
         in whole or in part, at

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         any time and from time to time following the occurrence of a Purchase
         Event (as hereinafter defined); provided that the Option shall
         terminate and be of no further force and effect upon the earliest to
         occur of (A) the Effective Time of the Merger, (B) termination of the
         Plan in accordance with the terms thereof prior to the occurrence of a
         Purchase Event or a Preliminary Purchase Event, other than a
         termination of the Plan by Grantee pursuant to Section 9.1(d) thereof
         (a "Default Termination"), (C) 12 months after the termination of the
         Plan by Grantee pursuant to a Default Termination, and (D) 12 months
         after termination of the Plan (other than pursuant to a Default
         Termination) following the occurrence of a Purchase Event or a
         Preliminary Purchase Event; and provided, further, that any purchase of
         shares upon exercise of the Option shall be subject to compliance with
         applicable laws, including without limitation the Bank Holding Company
         Act of 1956, as amended (the "BHCA"). The term "Holder" shall mean the
         holder or holders of the Option from time to time, and which is
         initially Grantee. The rights set forth in Section 8 hereof shall
         terminate when the right to exercise the Option terminates (other than
         as a result of a complete exercise of the Option) as set forth above.

         (b) As used herein, a "Purchase Event" means any of the following
events:

             (i) Without Grantee's prior written consent, Issuer shall have
         authorized, recommended or publicly-proposed, or publicly announced an
         intention to authorize, recommend or propose, or entered into an
         agreement with any person (other than Grantee or any subsidiary of
         Grantee) to effect (A) a merger, consolidation or similar transaction
         involving Issuer or any of its Subsidiaries, (B) the disposition, by
         sale, lease, exchange or otherwise, of assets of Issuer or any of its
         Subsidiaries representing in either case 25% or more of the
         consolidated assets of Issuer and its Subsidiaries, or (C) the
         issuance, sale or other disposition of (including by way of merger,
         consolidation, share exchange or any similar transaction) securities
         representing 20% or more of the voting power of Issuer or any of its
         Subsidiaries (any of the foregoing an "Acquisition Transaction"); or

             (ii) Any person (other than Grantee or any subsidiary of
         Grantee) shall have acquired beneficial ownership (as such term is
         defined in Rule 131-3 promulgated under the Exchange Act) of or the
         right to acquire beneficial ownership of, or any "group" (as such term
         is defined in Section 13(d)(3) of the Exchange Act) shall have been
         formed which beneficially owns or has the right to acquire beneficial
         ownership of, 20% or more of the then outstanding shares of Issuer
         Common Stock.

         (c) As used herein, a "Preliminary Purchase Event" means any of the
following events:

             (i) Any person (other than Grantee or any subsidiary of
         Grantee) shall have commenced (as such term is defined in Rule 14d-2
         under the Exchange Act), or shall have filed a registration statement
         under the Securities Act with respect to, a tender offer or exchange
         offer to purchase any shares of Issuer Common Stock such that, upon
         consummation of such offer, such person would own or control 15% or
         more of the then outstanding shares of Issuer Common Stock (such an
         offer being referred to herein as a "Tender Offer" and an "Exchange
         Offer," respectively); or



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             (ii) (A) the holders of Issuer Common Stock shall not have
         approved the Plan at the meeting of such stockholders held for the
         purpose of voting on the Plan, (B) such meeting shall not have been
         held or shall have been canceled prior to termination of the Plan or
         (C) Issuer's Board of Directors shall have withdrawn or modified in a
         manner adverse to Grantee the recommendation of Issuer's Board of
         Directors with respect to the Plan; in each case after it shall have
         been publicly announced that any person (other than Grantee or any
         subsidiary of Grantee) shall have (x) made, or disclosed an intention
         to make, a proposal to engage in an Acquisition Transaction, (y)
         commenced a Tender Offer or filed a registration statement under the
         Securities Act with respect to an Exchange Offer, or (z) filed an
         application (or given notice), whether in draft or final form, under
         the BHCA, the Home Owners Loan Act, as amended, the Bank Merger Act, as
         amended, the Change in Bank Control Act of 1978, as amended or any
         similar state banking law, for approval to engage in (or notice with
         respect to) an Acquisition Transaction; or

             (iii) Issuer shall have breached any representation, warranty,
         covenant or obligation contained in the Plan and such breach would
         entitle Grantee to terminate the Plan under Section 9.1(d) thereof
         (without regard to the cure period provided for therein unless such
         cure is promptly effected without jeopardizing consummation of the
         Merger pursuant to the terms of the Plan) after (x) a bona fide
         proposal is made by any person (other than Grantee or any subsidiary of
         Grantee) to Issuer or its stockholders to engage in an Acquisition
         Transaction, (y) any person (other than Grantee or any subsidiary of
         Grantee) states its intention to Issuer or its stockholders to make a
         proposal to engage in an Acquisition Transaction if the Plan terminates
         or (z) any person (other than Grantee or any subsidiary of Grantee)
         shall have filed an application or notice with any Governmental Entity
         to engage in an Acquisition Transaction.

         As used in this Agreement, "person" shall have the meaning specified in
Sections 3(a)(9) and 13(d)(3) of the Exchange Act.

         (d) Issuer shall notify Grantee promptly in writing of the occurrence
of any Preliminary Purchase Event or Purchase Event, it being understood that
the giving of such notice by Issuer shall not be a condition to the right of
Holder to exercise the Option.

         (e) In the event Holder wishes to exercise the Option, it shall send to
Issuer a written notice (the date of which being herein referred to as the
"Notice Date") specifying (i) the total number of Option Shares it intends to
purchase pursuant to such exercise, and (ii) a date not earlier than three
business days nor later than 15 business days from the Notice Date for the
closing (the "Closing") of such purchase (the "Closing Date"), provided that the
first notice of exercise shall be sent to Issuer within 180 days after the first
Purchase Event of which Grantee has been notified and, provided further, that if
prior notification to or approval of the Board of Governors of the Federal
Reserve System (the "Federal Reserve Board"), the Office of the Comptroller of
the Currency ("OCC") or any other Governmental Entity is required in connection
with such purchase, Holder shall promptly file the required notice or
application for approval and shall expeditiously process the same and the three
business day and 15 business day period of time that otherwise would run
pursuant to this sentence shall run instead from the date on which any required
notification periods have expired or been terminated or such



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approvals have been obtained and any requisite waiting period or periods shall
have passed. Any exercise of the Option shall be deemed to occur on the Notice
Date relating thereto.

         4. PAYMENT AND DELIVERY OF CERTIFICATES.

         (a) On each Closing Date, Holder shall:

             (i) Pay to Issuer, in immediately available funds by wire
         transfer to a bank account designated by Issuer, an amount equal to the
         Purchase Price multiplied by the number of Option Shares to be
         purchased on such Closing Date; and

             (ii) Present and surrender this Agreement to Issuer at the
         address of Issuer specified in Section 13(f) hereof.

         (b) At each Closing, simultaneously with the delivery of immediately
available funds and surrender of this Agreement as provided in Section 4(a),

             (i) Issuer shall deliver to Holder (A) a certificate or
         certificates representing the Option Shares to be purchased at such
         Closing, which Option Shares shall be free and clear of all liens,
         claims, charges and encumbrances of any kind whatsoever and subject to
         no preemptive rights, and (B) if the Option is exercised in part only,
         an executed new agreement with the same terms as this Agreement
         evidencing the right to purchase the balance of the shares of Issuer
         Common Stock purchasable hereunder; and

             (ii) Holder shall deliver to Issuer a letter agreeing that
         Holder shall not offer to sell or otherwise dispose of such Option
         Shares in violation of applicable federal and state law or of the
         provisions of this Agreement.

         (c) In addition to any other legend that is required by applicable law,
certificates for the Option Shares delivered at each Closing shall be endorsed
with a restrictive legend which shall read substantially as follows:

             THE TRANSFER OF THE STOCK REPRESENTED BY THIS CERTIFICATE IS
         SUBJECT TO RESTRICTIONS ARISING UNDER THE SECURITIES ACT OF 1933, AS
         AMENDED, AND PURSUANT TO THE TERMS OF A STOCK OPTION AGREEMENT DATED AS
         OF SEPTEMBER ___, 2001. A COPY OF SUCH AGREEMENT WILL BE PROVIDED TO
         THE HOLDER HEREOF WITHOUT CHARGE UPON RECEIPT BY ISSUER OF A WRITTEN
         REQUEST THEREFOR.

         It is understood and agreed that the above legend shall be removed by
delivery of substitute certificate(s) without such legend if Holder shall have
delivered to Issuer a copy of a letter from the staff of the Commission, or an
opinion of counsel in form and substance reasonably satisfactory to Issuer and
its counsel, to the effect that such legend is not required for purposes of the
Securities Act.

         (d) Upon the giving by Holder to Issuer of the written notice of
exercise of the Option provided for under Section 3(e), the tender of the
applicable Purchase Price in immediately


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available funds and the tender of this Agreement to Issuer, Holder shall be
deemed to be the holder of record of the shares of Issuer Common Stock issuable
upon such exercise, notwithstanding that the stock transfer books of Issuer
shall then be closed or that certificates representing such shares of Issuer
Common Stock shall not then be actually delivered to Holder.

         (e) Issuer agrees:

             (i) That it shall at all times maintain, free from preemptive
         rights, sufficient authorized but unissued or treasury shares of Issuer
         Common Stock so that the Option may be exercised without additional
         authorization of Issuer Common Stock after giving effect to all other
         options, warrants, convertible securities and other rights to purchase
         Issuer Common Stock;

             (ii) That it will not, by charter amendment or through
         reorganization, consolidation, merger, dissolution or sale of assets,
         or by any other voluntary act, avoid or seek to avoid the observance or
         performance of any of the covenants, stipulations or conditions to be
         observed or performed hereunder by Issuer;

             (iii) Promptly to take all action as may from time to time be
         required (including (A) complying with all premerger notification,
         reporting and waiting period requirements and (B) in the event prior
         approval of or notice to any Governmental Entity is necessary before
         the Option may be exercised, cooperating fully with Holder in preparing
         such applications or notices and providing such information to such
         Governmental Entity as it may require) in order to permit Holder to
         exercise the Option and Issuer duly and effectively to issue shares of
         Issuer Common Stock pursuant hereto; and

             (iv) Promptly to take all action provided herein to protect
         the rights of Holder against dilution.

         5. REPRESENTATIONS AND WARRANTIES OF ISSUER. Issuer hereby represents
and warrants to Grantee (and Holder, if different than Grantee) as follows:

         (a) DUE AUTHORIZATION. Issuer has all requisite corporate power and
authority to enter into this Agreement, and subject to any approvals referred to
herein, to consummate the transactions contemplated hereby. The execution and
delivery of this Agreement and the consummation of the transactions contemplated
hereby have been duly authorized by all necessary corporate action on the part
of Issuer, and this Agreement has been duly executed and delivered by Issuer.

         (b) NO VIOLATIONS. The execution and delivery of this Agreement, the
consummation of the transactions contemplated hereby and compliance by Issuer
with any of the provisions hereof will not (i) conflict with or result in a
breach of any provision of its Articles of Incorporation or Code of Regulations
or a default (or give rise to any right of termination, cancellation or
acceleration) under any of the terms, conditions or provisions of any note,
bond, debenture, mortgage, indenture, license, material agreement or other
material instrument or obligation to which Issuer is a party, or by which it or
any of its properties or assets may be


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bound, or (ii) violate any order, writ, injunction, decree, statute, rule or
regulation applicable to Issuer or any of its properties or assets.

         (c) AUTHORIZED STOCK. Issuer has taken all necessary corporate and
other action to authorize and reserve and to permit it to issue, and at all
times from the date hereof until the obligation to deliver Issuer Common Stock
upon the exercise of the Option terminates, will have reserved for issuance upon
exercise of the Option that number of shares of Issuer Common Stock equal to the
maximum number of shares of Issuer Common Stock at any time and from time to
time purchasable upon exercise of the Option, and all such shares, upon issuance
pursuant to the Option, will be duly and validly issued, fully paid and
nonassessable, and will be delivered free and clear of all liens, claims,
charges and encumbrances of any kind or nature whatsoever and not subject to any
preemptive rights.

         6. REPRESENTATIONS AND WARRANTIES OF GRANTEE. Grantee hereby represents
and warrants to Issuer as follows:

         (a) DUE AUTHORIZATION. Grantee has all requisite corporate power and
authority to enter into this Agreement and, subject to any approvals or consents
referred to herein, to consummate the transactions contemplated hereby. The
execution and delivery of this Agreement and the consummation of the
transactions contemplated hereby have been duly authorized by all necessary
corporate action on the part of Grantee, and this Agreement has been duly
executed and delivered by Grantee.

         (b) NO VIOLATIONS. The execution and delivery of this Agreement, the
consummation of the transactions contemplated hereby and compliance by Grantee
with any of the provisions hereof will not:

             (i) Conflict with or result in a breach of any provision of
         its Articles of Incorporation or Code of Regulations or a default (or
         give rise to any right of termination, cancellation or acceleration)
         under any of the terms, conditions or provisions of any note, bond,
         debenture, mortgage, indenture, license, material agreement or other
         material instrument or obligation to which Grantee is a party, or by
         which it or any of its properties or assets may be bound; or

             (ii) Violate any order, writ, injunction, decree, statute,
         rule or regulation applicable to Grantee or any of its properties or
         assets.

         7. ADJUSTMENT UPON CHANGES IN ISSUER CAPITALIZATION, ETC.

         (a) In the event of any change in Issuer Common Stock by reason of a
stock dividend, stock split, split-up, recapitalization, combination, exchange
of shares or similar transaction, the type and number of shares or securities
subject to the Option, and the Purchase Price therefor, shall be adjusted
appropriately, and proper provision shall be made in the agreements governing
such transactions so that Holder shall receive, upon exercise of the Option, the
number and class of shares or other securities or property that Holder would
have received in respect of Issuer Common Stock if the Option had been exercised
immediately prior to such event, or the record date therefor, as applicable. If
any additional shares of Issuer Common Stock are issued after the date of this
Agreement (other than pursuant to an event described in the first sentence of
this


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Section 7(a)), the number of shares of Issuer Common Stock for which the Option
may be exercisable shall be adjusted so that, after such adjustment, it,
together with any shares of Issuer Common Stock previously issued pursuant
hereto, would entitle the holders thereof after full exercise of the Option to
exercise 14.9% of the aggregate voting power then exercisable in the election of
the Issuer's directors by the holders of all Issuer voting securities then
issued and outstanding as determined without giving effect to any shares subject
to or issued pursuant to the Option.

         (b) In the event that Issuer shall enter in an agreement:

             (i) To consolidate with or merge into any person, other than
         Grantee or one of its Subsidiaries, and shall not be the continuing or
         surviving corporation of such consolidation or merger;

             (ii) To permit any person, other than Grantee or one of its
         Subsidiaries, to merge into Issuer and Issuer shall be the continuing
         or surviving corporation, but, in connection with such merger, the then
         outstanding shares of Issuer Common Stock shall be changed into or
         exchanged for stock or other securities of Issuer or any other person
         or cash or any other property or the outstanding shares of Issuer
         Common Stock immediately prior to such merger shall after such merger
         represent less than 50% of the outstanding shares and share equivalents
         of the merged company; or

             (iii) To sell or otherwise transfer assets representing more
         than 50% of the consolidated assets of Issuer and its Subsidiaries to
         any person, other than Grantee or one of its Subsidiaries, then, and in
         each such case (but at the election of the Holder in the case of clause
         (iii)), the agreement governing such transaction shall make proper
         provisions so that the Option shall, upon the consummation of any such
         transaction and upon the terms and conditions set forth herein, be
         converted into, or exchanged for, an option (the "Substitute Option"),
         at the election of Holder, of any of (x) the Acquiring Corporation (as
         hereinafter defined), (y) any person that controls the Acquiring
         Corporation or (z) in the case of a merger described in clause (ii),
         Issuer (such person being referred to as "Substitute Option Issuer").

         (c) The Substitute Option shall have the same terms as the Option,
provided that, if the terms of the Substitute Option cannot, for legal reasons,
be the same as the Option, such terms shall be as similar as possible and in no
event less advantageous to Holder. Substitute Option Issuer also shall enter
into an agreement with Holder in substantially the same form as this Agreement,
which shall be applicable to the Substitute Option.

         (d) The Substitute Option shall be exercisable for such number of
shares of Substitute Common Stock (as hereinafter defined) as is equal to the
Assigned Value (as hereinafter defined) multiplied by the number of shares of
Issuer Common Stock for which the Option was theretofore exercisable, divided by
the Average Price (as hereinafter defined). The exercise price of the Substitute
Option per share of Substitute Common Stock (the "Substitute Option Price")
shall then be equal to the Purchase Price multiplied by a fraction of which the
numerator is the number of shares of Issuer Common Stock for which the Option
was theretofore exercisable and


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the denominator is the number of shares of the Substitute Common Stock for which
the Substitute Option is exercisable.

         (e) The following terms have the meanings indicated:

             (1) "Acquiring Corporation" shall mean (i) the continuing or
         surviving corporation of a consolidation or merger with Issuer (if
         other than Issuer), (ii) Issuer in a merger in which Issuer is the
         continuing or surviving person, or (iii) the transferee of assets
         representing more than 50% of the consolidated assets of Issuer and its
         Subsidiaries.

             (2) "Issuer voting securities" means at any time any class of
         securities, including any shares of capital stock, issued by the Issuer
         entitling the holder thereof at such time to exercise voting power in
         the election of the Issuer's directors.

             (3) "Substitute Common Stock" shall mean the shares of capital
         stock (or similar equity interest) with the greatest voting power in
         respect of the election of directors (or persons similarly responsible
         for the direction of the business and affairs) of the Substitute Option
         Issuer.

             (4) "Assigned Value" shall mean the highest of (w) the price
         per share of Issuer Common Stock at which a Tender Offer or an Exchange
         Offer therefor has been made, (x) the price per share of Issuer Common
         Stock to be paid by any third party pursuant to an agreement with
         Issuer, (y) the highest closing price for shares of Issuer Common Stock
         within the six-month period immediately preceding the consolidation,
         merger or sale in question and (z) in the event of a sale of assets
         representing more than 50% of the consolidated assets of Issuer and its
         Subsidiaries or deposits, an amount equal to (i) the sum of the price
         paid in such sale for such assets (and/or deposits) and the current
         market value of the remaining assets of Issuer, as determined by a
         nationally-recognized investment banking firm selected by Holder,
         divided by (ii) the number of shares of Issuer Common Stock outstanding
         at such time. In the event that a Tender Offer or an Exchange Offer is
         made for Issuer Common Stock or an agreement is entered into for a
         merger or consolidation involving consideration other than cash, the
         value of the securities or other property issuable or deliverable in
         exchange for Issuer Common Stock shall be determined by a
         nationally-recognized investment banking firm selected by Holder.

             (5) "Average Price" shall mean the average closing price of a
         share of Substitute Common Stock for the one year immediately preceding
         the consolidation, merger or sale in question, but in no event higher
         than the closing price of the shares of Substitute Common Stock on the
         day preceding such consolidation, merger or sale; provided that if
         Issuer is the issuer of the Substitute Option, the Average Price shall
         be computed with respect to a share of common stock issued by Issuer,
         the person merging into Issuer or by any company which controls such
         person, as Holder may elect.

         (f) In no event, pursuant to any of the foregoing paragraphs, shall the
number of shares of Substitute Common Stock or other Issuer voting securities
subject to the Substitute


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Option, when added to aggregate of all Issuer voting securities in respect of
which the Grantee and each Holder may exercise or direct the exercise of voting
power in the election of Issuer's directors, exceed 19.9% of the aggregate of
such voting power then exercisable by the holders of all Issuer voting
securities then issued and outstanding, as determined without giving effect to
any shares subject to or issued pursuant to the Substitute Option.

         (g) Issuer shall not enter into any transaction described in Section
7(b) unless the Acquiring Corporation and any person that controls the Acquiring
Corporation assume in writing all the obligations of Issuer hereunder and take
all other actions that may be necessary so that the provisions of this Section 7
are given full force and effect (including, without limitation, any action that
may be necessary so that the holders of the other shares of common stock issued
by Substitute Option Issuer are not entitled to exercise any rights by reason of
the issuance or exercise of the Substitute Option and the shares of Substitute
Common Stock are otherwise in no way distinguishable from or have lesser
economic value (other than any diminution in value resulting from the fact that
the shares of Substitute Common Stock are restricted securities, as defined in
Rule 144 under the Securities Act or any successor provision) than other shares
of common stock issued by Substitute Option Issuer).

         8. REPURCHASE AT THE OPTION OF HOLDER.

         (a) Subject to the last sentence of Section 3(a), at the request of
Holder at any time commencing upon the first occurrence of a Repurchase Event
(as defined in Section 8(d)) and ending 12 months immediately thereafter, Issuer
shall repurchase from Holder (i) the Option and (ii) all shares of Issuer Common
Stock purchased by Holder pursuant hereto with respect to which Holder then has
beneficial ownership. The date on which Holder exercises its rights under this
Section 8 is referred to as the "Request Date." Such repurchase shall be at an
aggregate price (the "Section 8 Repurchase Consideration") equal to the sum of:

             (i) The aggregate Purchase Price paid by Holder for any shares
         of Issuer Common Stock acquired pursuant to the Option with respect to
         which Holder then has beneficial ownership;

             (ii) The excess, if any, of (x) the Applicable Price (as
         defined below) for each share of Issuer Common Stock over (y) the
         Purchase Price (subject to adjustment pursuant to Section 7),
         multiplied by the number of shares of Issuer Common Stock with respect
         to which the Option has not been exercised; and

             (iii) The excess, if any, of the Applicable Price over the
         Purchase Price (subject to adjustment pursuant to Section 7) paid (or,
         in the case of Option Shares with respect to which the Option has been
         exercised but the Closing Date has not occurred, payable) by Holder for
         each share of Issuer Common Stock with respect to which the Option has
         been exercised and with respect to which Holder then has beneficial
         ownership, multiplied by the number of such shares.

         (b) If Holder exercises its rights under this Section 8, Issuer shall,
within 10 business days after the Request Date, pay the Section 8 Repurchase
Consideration to Holder in immediately available funds, and contemporaneously
with such payment Holder shall surrender


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to Issuer the Option and the certificates evidencing the shares of Issuer Common
Stock purchased thereunder with respect to which Holder then has beneficial
ownership, and shall warrant that it has sole record and beneficial ownership of
such shares and that the same are then free and clear of all liens, claims,
charges and encumbrances of any kind whatsoever. Notwithstanding the foregoing,
to the extent that prior notification to or approval of the Federal Reserve
Board, the OCC or any other Governmental Entity is required in connection with
the payment of all or any portion of the Section 8 Repurchase Consideration,
Holder shall have the ongoing option to revoke its request for repurchase
pursuant to Section 8, in whole or in part, or to require that Issuer deliver
from time to time that portion of the Section 8 Repurchase Consideration that it
is not then so prohibited from paying and promptly file the required notice or
application for approval and expeditiously process the same (and each party
shall cooperate with the other in the filing of any such notice or application
and the obtaining of any such approval), in which case the ten-day period
referred to in the first sentence of this Section 8(b) shall run instead from
the date on which any required notification periods have expired or been
terminated or such approvals have been obtained and any requisite waiting period
or periods shall have passed. If the Federal Reserve Board, the OCC or any other
Governmental Entity disapproves of any part of Issuer's proposed repurchase
pursuant to this Section 8, Issuer shall promptly give notice of such fact to
Holder. If the Federal Reserve Board, the OCC or any other Governmental Entity
prohibits the repurchase in part but not in whole, then Holder shall have the
right (i) to revoke the repurchase request or (ii) to the extent permitted by
the Federal Reserve Board, the OCC or other Governmental Entity, determine
whether the repurchase should apply to the Option and/or Option Shares and to
what extent to each, and Holder shall thereupon have the right to exercise the
Option as to the number of Option Shares for which the Option was exercisable at
the Request Date less the sum of the number of shares covered by the Option in
respect of which payment has been made pursuant to Section 8(a)(ii) and the
number of shares covered by the portion of the Option (if any) that has been
repurchased. Holder shall notify Issuer of its determination under the preceding
sentence within five business days of receipt of notice of disapproval of the
repurchase.

         Notwithstanding anything herein to the contrary, all of Grantee's and
any Holder's rights under this Section 8 shall terminate on the date of
termination of the Option pursuant to Section 3(a).

         (c) For purposes of this Agreement, the "Applicable Price" means the
highest of:

             (i) The highest price per share of Issuer Common Stock paid
         for any such share by the person or groups described in Section
         8(d)(i);

             (ii) The price per share of Issuer Common Stock received by
         holders of Issuer Common Stock in connection with any merger or other
         business combination transaction described in Sections 7(b)(i),
         7(b)(ii) or 7(b)(iii); or

             (iii) The highest closing sales price per share of Issuer
         Common Stock quoted on the NASDAQ Stock Market's National Market
         ("NASDAQ/NMS") (or if Issuer Common Stock is not quoted on NASDAQ/NMS,
         the highest bid price per share as quoted on the principal trading
         market or securities exchange on which such shares are


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         traded, as reported by a recognized source chosen by Holder) during the
         60 business days preceding the Request Date;

provided, however, that in the event of a sale of less than all of Issuer's
assets, the Applicable Price shall be the sum of the price paid in such sale for
such assets and the current market value of the remaining assets of Issuer as
determined by a nationally-recognized investment banking firm selected by
Holder, divided by the number of shares of Issuer Common Stock outstanding at
the time of such sale. If the consideration to be offered, paid or received
pursuant to either of the foregoing clauses (i) or (ii) shall be other than in
cash, the value of such consideration shall be determined in good faith by an
independent nationally-recognized investment banking firm selected by Holder and
reasonably acceptable to Issuer, which determination shall be conclusive for all
purposes of this Agreement.

         (d) As used herein, a "Repurchase Event" shall occur if:

             (i) Any person (other than Grantee or any subsidiary of
         Grantee) shall have acquired beneficial ownership of (as such term is
         defined in Rule 13d-3 promulgated under the Exchange Act), or the right
         to acquire beneficial ownership of, or any "group" (as such term is
         defined in Section 13(d)(3) of the Exchange Act) shall have been formed
         which beneficially owns or has the right to acquire beneficial
         ownership of, 50% or more of the then outstanding shares of Issuer
         Common Stock; or

             (ii) Any of the transactions described in Section 7(b)(i),
         Section 7(b)(ii) or Section 7(b)(iii) shall be consummated.

         9. REGISTRATION RIGHTS.

         (a) DEMAND REGISTRATION RIGHTS. Issuer shall, subject to the conditions
of Section 9(c), if requested by any Holder, as expeditiously as possible
prepare and file a registration statement under the Securities Act if such
registration is necessary in order to permit the sale or other disposition of
any or all shares of Issuer Common Stock or other securities that have been
acquired by or are issuable to Holder upon exercise of the Option in accordance
with the intended method of sale or other disposition stated by Holder in such
request, including without limitation a "shelf" registration statement under
Rule 415 under the Securities Act or any successor provision, and Issuer shall
use its best efforts to qualify such shares or other securities for sale under
any applicable state securities laws.

         (b) ADDITIONAL REGISTRATION RIGHTS. If Issuer at any time after the
exercise of the Option proposes to register any shares of Issuer Common Stock
under the Securities Act in connection with an underwritten public offering of
such Issuer Common Stock, Issuer will promptly give written notice to Holder of
its intention to do so and, upon the written request of Holder given within 30
days after receipt of any such notice (which request shall specify the number of
shares of Issuer Common Stock intended to be included in such underwritten
public offering by Holder), Issuer will cause all such shares for which a Holder
shall have requested participation in such registration to be so registered and
included in such underwritten public offering; provided, however, that Issuer
may elect to not cause any such shares to be so registered (i) if the
underwriters in good faith object for valid business reasons, or (ii) in the
case


                                       11
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of a registration solely to implement an employee benefit plan or a registration
filed on Form S-4 under the Securities Act or any successor form; provided,
further, however, that such election pursuant to clause (i) may only be made one
time. If some but not all the shares of Issuer Common Stock with respect to
which Issuer shall have received requests for registration pursuant to this
Section 9(b) shall be excluded from such registration, Issuer shall make
appropriate allocation of shares to be registered among Holders permitted to
register their shares of Issuer Common Stock in connection with such
registration pro rata in the proportion that the number of shares requested to
be registered by each such Holder bears to the total number of shares requested
to be registered by all such Holders then desiring to have Issuer Common Stock
registered for sale.

         (c) CONDITIONS TO REQUIRED REGISTRATION. Issuer shall use all
reasonable efforts to cause each registration statement referred to in Section
9(a) to become effective and to obtain all consents or waivers of other parties
which are required therefor and to keep such registration statement effective;
provided, however, that Issuer may delay any registration of Option Shares
required pursuant to Section 9(a) for a period not exceeding 90 days if Issuer
shall in good faith determine that any such registration would adversely affect
an offering or contemplated offering of other securities by Issuer, and Issuer
shall not be required to register Option Shares under the Securities Act
pursuant to Section 9(a):

             (i) Prior to the earliest of (A) termination of the Plan
         pursuant to Article VII thereof, and (B) a Purchase Event or a
         Preliminary Purchase Event;

             (ii) On more than one occasion during any calendar year and on
         more than two occasions in total;

             (iii) Within 90 days after the effective date of a
         registration referred to in Section 9(b) pursuant to which the Holder
         or Holders concerned were afforded the opportunity to register such
         shares under the Securities Act and such shares were registered as
         requested; and

             (iv) Unless a request therefor is made to Issuer by the Holder
         or Holders of at least 25% or more of the aggregate number of Option
         Shares (including shares of Issuer Common Stock issuable upon exercise
         of the Option) then outstanding.

         In addition to the foregoing, Issuer shall not be required to maintain
the effectiveness of any registration statement after the expiration of nine
months from the effective date of such registration statement. Issuer shall use
all reasonable efforts to make any filings, and take all steps, under all
applicable state securities laws to the extent necessary to permit the sale or
other disposition of the Option Shares so registered in accordance with the
intended method of distribution for such shares, provided, however, that Issuer
shall not be required to consent to general jurisdiction or to qualify to do
business in any state where it is not otherwise required to so consent to such
jurisdiction or to so qualify to do business.

         (d) EXPENSES. Issuer will pay all expenses (including without
limitation registration fees, qualification fees, blue sky fees and expenses,
accounting expenses, legal expenses and printing expenses incurred by it) in
connection with each registration pursuant to Section 9(a) or


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(b) and all other qualifications, notifications or exemptions pursuant to
Section 9(a) or (b); provided, however, that underwriting discounts and
commissions relating to Option Shares, fees and disbursements of counsel to the
Holder(s) of Option Shares being registered and any other expenses incurred by
such Holder(s) in connection with any such registration shall be borne by such
Holder(s)

         (e) Indemnification. In connection with any registration under Section
9(a) or (b), Issuer hereby indemnifies each Holder, and each underwriter
thereof, including each person, if any, who controls such Holder or underwriter
within the meaning of Section 15 of the Securities Act, against all expenses,
losses, claims, damages and liabilities caused by any untrue, or alleged untrue,
statement of a material fact contained in any registration statement or
prospectus or notification or offering circular (including any amendments or
supplements thereto) or any preliminary prospectus, or caused by any omission,
or alleged omission, to state therein a material fact required to be stated
therein or necessary to make the statements therein not misleading, except
insofar as such expenses, losses, claims, damages or liabilities of such
indemnified party are caused by any untrue statement or alleged untrue statement
that was included by Issuer in any such registration statement or prospectus or
notification or offering circular (including any amendments or supplements
thereto) in reliance upon, and in conformity with, information furnished in
writing to Issuer by such indemnified party expressly for use therein, and
Issuer and each officer, director and controlling person of Issuer shall be
indemnified by such Holder, or by such underwriter, as the case may be, for all
such expenses, losses, claims, damages and liabilities caused by any untrue, or
alleged untrue, statement that was included by Issuer in any such registration
statement or prospectus or notification or offering circular (including any
amendments or supplements thereto) in reliance upon, and in conformity with,
information furnished in writing to Issuer by such Holder or such underwriter,
as the case may be, expressly fort such use.

         Promptly upon receipt by a party indemnified under this Section 9(e) of
notice of the commencement of any action against such indemnified party in
respect of which indemnity or reimbursement may be I sought against any
indemnifying party under this Section 9(e), such indemnified party shall notify
the indemnifying party in writing of the commencement of such action, but,
except to the extent of any actual prejudice to the indemnifying party, the
failure so to notify the indemnifying party shall not relieve it of any
liability which it may otherwise have to any indemnified party under this
Section 9(e). In case notice of commencement of any such action shall be given
to the indemnifying party as above provided, the indemnifying party shall be
entitled to participate in and, to the extent it my wish, jointly with any other
indemnifying party similarly notified, to assume the defense of such action at
its own expense, with counsel chosen by it and reasonably satisfactory to such
indemnified party. The indemnified party shall have the right to employ separate
counsel in any such action and participate in the defense thereof, but the fees
and expenses of such counsel (other than reasonable costs of investigation)
shall be paid by the indemnified party unless (i) the indemnifying party agrees
to pay the same, (ii) the indemnifying party fails to assume the defense of such
action with counsel reasonably satisfactory to the indemnified party, or (iii)
the indemnified party has been advised by counsel that one or more legal
defenses may be available to the indemnifying party that may be contrary to the
interest of the indemnified party, in which case the indemnifying party shall be
entitled to assume the defense of such action notwithstanding its obligation to
bear fees and expenses of


                                       13
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such counsel. No indemnifying party shall be liable for any settlement entered
into without its consent, which consent may not be unreasonably withheld.

         If the indemnification provided for in this Section 9(e) is unavailable
to a party otherwise entitled to be indemnified in respect of any expenses,
losses, claims, damages or liabilities referred to herein, then the indemnifying
party, in lieu of indemnifying such party otherwise entitled to be indemnified,
shall contribute to the amount paid or payable by such party to be indemnified
as a result of such expenses, losses, claims, damages or liabilities in such
proportion as is appropriate to reflect the relative fault of Issuer, the
selling Holders and the underwriters in connection with the statement or
omissions which results in such expenses, losses, claims, damages or
liabilities, as well as any other relevant equitable considerations. The amount
paid or payable by a party as a result of the expenses, losses, claims, damages
and liabilities referred to above shall be deemed to include any legal or other
fees or expenses reasonably incurred by such party in connection with
investigating or defending any action or claim; provided, however, that in no
case shall the selling Holders be responsible, in the aggregate, for any amount
in excess of the net offering proceeds attributable to its Option Shares
included in the offering. No person guilty of fraudulent misrepresentation
(within the meaning of Section 11(g) of the Securities Act) shall be entitled to
contribution from any person who was not guilty of such fraudulent
misrepresentation. Any obligation by any Holder to indemnify shall be several
and not joint with other Holders.

         In connection with any registration pursuant to Section 9(a) or (b)
above, Issuer and each selling Holder (other than Grantee) shall enter into an
agreement containing the indemnification provisions of this Section 9(e).

         (f) Miscellaneous Reporting. Issuer shall comply with all reporting
requirements and will do all such other things as may be necessary to permit the
expeditious sale at any time of any Option Shares by the Holder(s) in accordance
with and to the extent permitted by any rule or regulation permitting
nonregistered sales of securities promulgated by the Commission from time to
time, including, without limitation, Rule 144A. Issuer shall at its expense
provide the Holder with any information necessary in connection with the
completion and filing of any reports or forms required to be filed by them under
the Securities Act or the Exchange Act, or required pursuant to any state
securities laws or the rules of any stock exchange.

         (g) Issue Taxes. Issuer will pay all stamp taxes in connection with the
issuance and the sale of the Option Shares and in connection with the exercise
of the Option, and will save any Holder harmless, without limitation as to time,
against any and all liabilities, with respect to all such taxes.

         10. QUOTATION; LISTING. If Issuer Common Stock or any other securities
to be acquired upon exercise of the Option are then authorized for quotation or
trading or listing on NASDAQ/NMS or any securities exchange, Issuer, upon the
request of Holder, will promptly file an application, if required, to authorize
for quotation or trading or listing the shares of Issuer Common Stock or other
securities to be acquired upon exercise of the Option on NASDAQ/NMS or such
other securities exchange and will use its best efforts to obtain approval, if
required, of such quotation or listing as soon as practicable.


                                       14
   15


         11. DIVISION OF OPTION. Upon the occurrence of a Purchase Event or a
Preliminary Purchase Event, this Agreement (and the Option granted hereby) are
exchangeable, without expense, at the option of Holder, upon presentation and
surrender of this Agreement at the principal office of the Issuer for other
Agreements providing for Options of different denominations entitling the holder
thereof to purchase in the aggregate the same number of shares of Issuer Common
Stock purchasable hereunder. The terms "Agreement" and "Option" as used herein
include any other Agreements and related Options for which this Agreement (and
the Option granted hereby) may be exchanged. Upon receipt by Issuer of evidence
reasonably satisfactory to it of the loss, theft, destruction or mutilation of
this Agreement, and (in the case of loss, theft or destruction) of reasonably
satisfactory indemnification, and upon surrender and cancellation of this
Agreement, if mutilated, Issuer will execute and deliver a new Agreement of like
tenor and date. Any such new Agreement executed and delivered shall constitute
an additional contractual obligation on the part of Issuer, whether or not the
Agreement so lost, stolen, destroyed or mutilated shall at any time be
enforceable by anyone.

         12. LIMITATION OF GRANTEE PROFIT; MINIMUM PROFIT.


         (a) Notwithstanding any other provision herein, in no event shall
Grantee's Total Profit (as defined below) exceed $11,000,000 (the "Maximum
Profit") and, if it otherwise would exceed such amount, Grantee, at its sole
discretion, shall either:

             (i) Reduce the number of Option Shares;

             (ii) Deliver to Issuer for cancellation shares of Issuer
         common stock (or other securities) into which such Option Shares are
         converted or exchanged;

             (iii) Pay cash to Issuer; or

             (iv) Any combination of the foregoing, so that Grantee's
         actually realized Total Profit shall not exceed the Maximum Profit
         after taking into account the foregoing actions.

         (b) If a Repurchase Event occurs, notwithstanding any other provision
herein, in no event shall Grantee's Total Profit be less than $8,000,000 (the
"Minimum Profit") and, if it otherwise would be less than such amount, Issuer
shall pay cash to Grantee in an amount equal to the excess of Minimum Profit
over Total Profit.

         (c) For purposes of this Agreement, "Total Profit" shall mean: The
aggregate amount of (A) any excess of (x) the net cash amounts received by
Grantee pursuant to a sale of Option Shares (or securities into which such
shares are converted or exchanged) (including amounts paid to Grantee in respect
of Option Shares repurchased by Issuer pursuant to Section 8) over (y) the
Grantee's aggregate purchase price for such Option Shares (or other securities),
plus (B) any amounts received by Grantee on the repurchase of the Option by
Issuer pursuant to Section 8, plus (C) any cash previously paid by Grantee to
Issuer pursuant to this Section 12 and the value of the Option Shares (or other
securities) previously delivered by Grantee to Issuer for cancellation pursuant
to this Section 12.


                                       15
   16


         (d) Notwithstanding any other provision of this Agreement, nothing in
this Agreement shall affect the ability of Grantee to receive, nor relieve
Issuer's obligation to pay, the liquidated damages provided for in Section
10.3(b) of the Plan.

         13. MISCELLANEOUS.

         (a) EXPENSES. Except as otherwise provided in Section 9, each of the
parties hereto shall bear and pay all costs and expenses incurred by it or on
its behalf in connection with the transactions contemplated hereunder, including
fees and expenses of its own financial consultants, investment bankers,
accountants and counsel.

         (b) WAIVER AND AMENDMENT. Any provision of this Agreement may be waived
at any time by the party that is entitled to the benefits of such provision by
written instrument signed by a duly authorized executive officer of such party.
This Agreement may not be modified, amended, altered or supplemented except upon
the execution and delivery of a written agreement executed by the parties
hereto.

         (c) ENTIRE AGREEMENT; NO THIRD PARTY BENEFICIARIES; SEVERABILITY. This
Agreement, together with the Plan and the other documents and instruments
referred to herein and therein, between Grantee and Issuer (i) constitutes the
entire agreement and supersedes all prior agreements and understandings, both
written and oral, between the parties with respect to the subject matter hereof,
and (ii) is not intended to confer upon any person other than the parties hereto
(other than the indemnified parties under Section 9(e) and any transferee of the
Option Shares or any permitted transferee of this Agreement pursuant to Section
13(h)) any rights or remedies hereunder. If any term, provision, covenant or
restriction of this Agreement is held by a court of competent jurisdiction or a
federal or state regulatory agency to be invalid, void or unenforceable, the
remainder of the terms, provisions, covenants and restrictions of this Agreement
shall remain in full force and effect and shall in no way be affected, impaired
or invalidated. If for any reason such court or regulatory agency determines
that the Option does not permit Holder to acquire, or does not require Issuer to
repurchase, the full number of shares of Issuer Common Stock as provided in
Sections 3 and 8 (as adjusted pursuant to Section 7), it is the express
intention of Issuer to allow Holder to acquire or to require Issuer to
repurchase such lesser number of shares as may be permissible without any
amendment or modification hereof.

         (d) 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 rules.

         (e) DESCRIPTIVE HEADINGS. The descriptive headings contained herein are
for convenience of reference only and shall not affect in any way the meaning or
interpretation of this Agreement.

         (f) NOTICES. All notices and other communications hereunder shall be in
writing and shall be deemed given if delivered personally, telecopied (with
confirmation) or sent by overnight mail service or mailed by registered or
certified mail (return receipt requested) postage prepaid, to the parties at the
following address (or at such other address for a party as shall be specified by
like notice).


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         If to Grantee:

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

         With a required copy to:

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

         If to Issuer:

                                    BancFirst Ohio Corp.
                                    422 Main Street
                                    P.O. Box 4658
                                    Zanesville, OH 43702-4658
                                    Attention:  Gary Fields
                                    President and Chief Executive Officer
                                    Fax:  (740) 455-5705

         With a required copy to:

                                    Michael F. Sullivan
                                    Bricker & Eckler LLP
                                    100 South Third Street
                                    Columbus, Ohio 43215-4291
                                    Fax:  (614) 227-2390

         (g) COUNTERPARTS. This Agreement and any amendments hereto may be
executed in two counterparts, each of which shall be considered one and the same
agreement and shall become effective when both counterparts have been signed, it
being understood that both parties need not sign the same counterpart.

         (h) ASSIGNMENT. Neither this Agreement nor any of the rights, interests
or obligations hereunder or under the Option shall be assigned by any of the
parties hereto (whether by operation of law or otherwise) without the prior
written consent of the other party, except that Holder may assign this Agreement
to a wholly-owned subsidiary of Holder and Holder may assign its rights
hereunder in whole or in part after the occurrence of a Purchase Event. Subject
to the preceding sentence, this Agreement shall be binding upon, inure to the
benefit of and be enforceable by the parties and their respective successors and
assigns.


                                       17
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         (i) FURTHER ASSURANCES. In the event of any exercise of the Holder,
Issuer and Holder shall execute and deliver all other and instruments and take
all other action that may be reasonably in order to consummate the transactions
provided for by such

         (j) SPECIFIC PERFORMANCE. The parties hereto agree that this Agreement
may be enforced by either party through specific performance, injunctive relief
and other equitable relief. Both parties further agree to waive any requirement
for the securing or posting of any bond in connection with the obtaining of any
such equitable relief and that this provision is without prejudice to any other
rights that the parties hereto may have for any failure to perform this
Agreement.

         IN WITNESS WHEREOF, Issuer and Grantee have caused this Stock Option
Agreement to be signed by their respective officers thereunto duly authorized,
all as of the day and year first written above.


                                       ISSUER:

ATTEST:                                BANCFIRST OHIO CORP.


By: /s/ James H. Nicholson             By: /s/ Gary N. Fields
   -----------------------------          --------------------------------

Name:   James H. Nicholson             Name:   Gary N. Fields
     ---------------------------            ------------------------------

Title:  EVP & Secretary                Title: President & CEO
      --------------------------             -----------------------------



                                       GRANTEE:

ATTEST:                                UNB CORP.


By: /s/ James J. Pennetti              By: /s/ Roger L. Mann
   -----------------------------          --------------------------------

Name:   James J. Pennetti              Name:   Roger L. Mann
     ---------------------------            ------------------------------

Title:  EVP & CFO                      Title: Chairman & CEO
      --------------------------             -----------------------------



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