PARK NATIONAL CORP /OH/
S-4, 2000-12-29
NATIONAL COMMERCIAL BANKS
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<PAGE>   1


    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON DECEMBER 29, 2000
                                                     REGISTRATION NO. 333-
================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                               -------------------

                                    FORM S-4

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                              --------------------

                            PARK NATIONAL CORPORATION
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

<TABLE>
<S>                                          <C>                                        <C>
                OHIO                                      6021                                 31-1179518
    (STATE OR OTHER JURISDICTION              (PRIMARY STANDARD INDUSTRIAL                  (I.R.S. EMPLOYER
 OF INCORPORATION OR ORGANIZATION)            CLASSIFICATION CODE NUMBER)                  IDENTIFICATION NO.)
</TABLE>

                              50 NORTH THIRD STREET
                                  P.O. BOX 3500
                             NEWARK, OHIO 43058-3500
                                 (740) 349-8451
    (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                  OF REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

                           DAVID C. BOWERS, SECRETARY
                            PARK NATIONAL CORPORATION
                              50 NORTH THIRD STREET
                                  P.O. BOX 3500
                             NEWARK, OHIO 43058-3500
                                 (740) 349-3708
            (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
                   INCLUDING AREA CODE, OF AGENT FOR SERVICE)

                           --------------------------

                                   COPIES TO:
<TABLE>
<S>                                                       <C>
CHARLES S. DEROUSIE, ESQ. AND                               MARTIN WERNER, ESQ.
ELIZABETH TURRELL FARRAR, ESQ.                              WERNER & BLANK CO., L.P.A.
VORYS, SATER, SEYMOUR AND PEASE LLP                         7205 WEST CENTRAL AVENUE
52 EAST GAY STREET                                          TOLEDO, OHIO 43617
COLUMBUS, OHIO 43215                                        (419) 841-8051
(614) 464-6400
</TABLE>

       APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE OF THE SECURITIES TO
THE PUBLIC: As soon as practicable following the effective date of the
Registration Statement and upon the effective date of the merger of Security
Banc Corporation with and into the Registrant pursuant to the Agreement and Plan
of Merger described in the enclosed joint proxy statement/prospectus included as
Part I of this Registration Statement.

       If the securities being registered on this Form are being offered in
connection with the formation of a holding company and there is compliance with
General Instruction G, check the following box: [ ]

       If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering: [ ]

       If this Form is a post-effective amendment filed pursuant to Rule 462(d)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering: [ ]


<PAGE>   2


                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
================================ ================== ======================= ======================= ================
                                                       Proposed maximum        Proposed maximum        Amount of
    Title of each class of         Amount to be            offering               aggregate          registration
  securities being registered     registered (1)        price per unit        offering price (2)          fee
-------------------------------- ------------------ ----------------------- ----------------------- ----------------
<S>                              <C>                <C>                     <C>                     <C>
Common Shares,
without par value...........          3,350,000              N/A                 $258,373,294           $64,594
================================ ================== ======================= ======================= ================
</TABLE>

(1)  Represents the estimated maximum number of common shares of the Registrant
     that the Registrant expects would be issuable to shareholders of Security
     Banc Corporation pursuant to the terms of the Agreement and Plan of Merger
     between the Registrant and Security Banc Corporation.

(2)  Estimated solely for the purpose of computing the registration fee in
     accordance with Rule 457(c) and Rule 457(f)(1) of the General Rules and
     Regulations under the Securities Act of 1933 based upon the market value of
     the securities to be cancelled in exchange for common shares of the
     Registrant in the merger. On December 27, 2000, there were 11,777,700
     common shares of Security Banc Corporation outstanding (excluding common
     shares issuable upon exercise of outstanding options) and the average of
     the bid and asked prices of such common shares on such date was $21.9375,
     resulting in an aggregate value of $258,373,294.

                               -------------------

       THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a),
MAY DETERMINE.
================================================================================


<PAGE>   3


The information in this joint proxy statement/prospectus is not complete and may
be changed. We may not sell these securities until the registration statement
filed with the Securities and Exchange Commission, which includes this joint
proxy statement/prospectus, is effective. This joint proxy statement/prospectus
is not an offer to sell these securities and it is not soliciting an offer to
buy these securities in any state where the offer or sale is not permitted.


<PAGE>   4


                            PARK NATIONAL CORPORATION
                              50 NORTH THIRD STREET
                               NEWARK, OHIO 43055

                            -------------------------

                    NOTICE OF SPECIAL MEETING OF SHAREHOLDERS

       A special meeting of shareholders of Park National Corporation, an Ohio
corporation, will be held at the offices of The Park National Bank, 50 North
Third Street, Newark, Ohio, on [      ], [      ], 2001, at [ ]:00 [_.M.], local
time, for the following purposes:

       1.     To consider and vote on a proposal to adopt the Agreement and Plan
              of Merger, dated as of November 20, 2000, by and between Park and
              Security Banc Corporation, an Ohio corporation. Subject to the
              terms and conditions of the merger agreement, at the effective
              time of the merger, each outstanding Security common share (other
              than those as to which dissenters' rights are perfected under the
              Ohio General Corporation Law) will be converted into the right to
              receive Park common shares as more fully described in the
              accompanying joint proxy statement/prospectus.

       2.     To transact any other business which properly comes before the
              special meeting or any adjournment of the special meeting.

       THE BOARD OF DIRECTORS OF PARK UNANIMOUSLY RECOMMENDS THAT YOU VOTE IN
FAVOR OF THE PROPOSAL TO ADOPT THE AGREEMENT AND PLAN OF MERGER.

       We have fixed [         ], 2001 as the record date for determining those
shareholders entitled to vote at the special meeting and any adjournment of the
special meeting. Accordingly, only shareholders of record as of the close of
business on that date will be entitled to notice of, and to vote at, the special
meeting and any adjournment of the special meeting.

       Whether or not you plan to attend the special meeting, please complete,
sign and date the enclosed proxy card and promptly return it in the accompanying
envelope, which requires no postage if mailed in the United States. You may
revoke your proxy at any time before it is voted at the special meeting by
delivering a later-dated executed proxy card or a written notice of revocation
to Park or by voting in person at the special meeting. Your attendance at the
special meeting will not, in and of itself, constitute a revocation of your
proxy.

                                 By Order of the Board of Directors,



Newark, Ohio
[       ], 2001                  David C. Bowers, Secretary


<PAGE>   5


                            SECURITY BANC CORPORATION
                            40 SOUTH LIMESTONE STREET
                             SPRINGFIELD, OHIO 45502

                            -------------------------

                    NOTICE OF SPECIAL MEETING OF SHAREHOLDERS

       A special meeting of shareholders of Security Banc Corporation, an Ohio
corporation, will be held at [                   ], Ohio, on [     ], [     ],
2001, at [ ]:00 [_.m.], local time, for the following purposes:

       1.     To consider and vote on a proposal to adopt the Agreement and Plan
              of Merger, dated as of November 20, 2000, by and between Security
              and Park National Corporation, an Ohio corporation. Subject to the
              terms and conditions of the merger agreement, at the effective
              time of the merger, each outstanding Security common share (other
              than those as to which dissenters' rights are perfected under the
              Ohio General Corporation Law) will be converted into the right to
              receive Park common shares as more fully described in the
              accompanying joint proxy statement/prospectus.

       2.     To transact any other business which properly comes before the
              special meeting or any adjournment of the special meeting.

       THE BOARD OF DIRECTORS OF SECURITY UNANIMOUSLY RECOMMENDS THAT YOU VOTE
IN FAVOR OF THE PROPOSAL TO ADOPT THE AGREEMENT AND PLAN OF MERGER.

       We have fixed [         ], 2001 as the record date for determining those
shareholders entitled to vote at the special meeting and any adjournment of the
special meeting. Accordingly, only shareholders of record as of the close of
business on that date will be entitled to notice of, and to vote at, the special
meeting and any adjournment of the special meeting.

       Whether or not you plan to attend the special meeting, please complete,
sign and date the enclosed proxy card and promptly return it in the accompanying
envelope, which requires no postage if mailed in the United States. You may
revoke your proxy at any time before it is voted at the special meeting by
delivering a later-dated executed proxy card or a written notice of revocation
to Security or by voting in person at the special meeting. Your attendance at
the special meeting will not, in and of itself, constitute a revocation of your
proxy.

                                    By Order of the Board of Directors,



Springfield, Ohio
[      ], 2001                      J. William Stapleton, Executive
                                    Vice President and Secretary


<PAGE>   6


<TABLE>
<S>                                                           <C>
----------------------------------------------------          ------------------------------------------------------
             PARK NATIONAL CORPORATION                                       PARK NATIONAL CORPORATION
                    PROSPECTUS                                                          AND
                        FOR                                                  SECURITY BANC CORPORATION
            3,350,000 COMMON SHARES OF                                         JOINT PROXY STATEMENT
             PARK NATIONAL CORPORATION                                                  FOR
   TO BE ISSUED IN CONNECTION WITH THE MERGER OF                        SPECIAL MEETING OF SHAREHOLDERS OF
             SECURITY BANC CORPORATION                                       PARK NATIONAL CORPORATION
                       INTO                                                  TO BE HELD ON [ ], 2001,
             PARK NATIONAL CORPORATION                                           AT [ ]:00 [_.M.]
                                                                                        AND
                                                                        SPECIAL MEETING OF SHAREHOLDERS OF
                                                                             SECURITY BANC CORPORATION
                                                                              TO BE HELD ON [ ], 2001
                                                                                 AT [ ]:00 [_.M.]
----------------------------------------------------          ------------------------------------------------------
</TABLE>


       The boards of directors of Park National Corporation and Security Banc
Corporation have each unanimously approved a merger agreement to combine our
corporations. If the merger is completed, Security will merge into Park. Each
common share of Park that a Park shareholder holds prior to the merger will
continue to be one Park common share after the merger. Each common share of
Security that a Security shareholder holds prior to the merger will be converted
into approximately .2844 Park common shares. In lieu of issuing fractional
shares, Park will make a cash payment based on a formula in the merger
agreement. Following the merger, Security's subsidiaries, Security National Bank
and Trust Company, The Citizens National Bank of Urbana and The Third Savings
and Loan Company, will be subsidiaries of Park, and Security will no longer
exist as a separate entity.

       Park common shares are listed on the American Stock Exchange under the
symbol "PRK". On November 20, 2000, the last trading day prior to the joint
public announcement by Park and Security of the signing of the merger agreement,
Park common shares closed at $91.375 per share. On [         ], the last trading
day before the date of this joint proxy statement/prospectus, Park common shares
closed at $[   ] per share.

       Park and Security cannot complete the merger unless the shareholders of
both Park and Security vote to adopt the merger agreement. YOUR VOTE IS VERY
IMPORTANT. IF YOU FAIL TO VOTE, THE EFFECT WILL BE A VOTE "AGAINST" ADOPTION OF
THE MERGER AGREEMENT.

       Each of our corporations will hold a special meeting of our shareholders
to vote on the adoption of the merger agreement. This document is a joint proxy
statement for use by both Park and Security in soliciting proxies for their
special meetings of shareholders. It is also a prospectus for Park relating to
the Park common shares that will be issued to Security shareholders in the
merger in exchange for their Security common shares. This document gives
detailed information about the merger, and includes a copy of the merger
agreement. We urge you to read the entire document before deciding how to vote.
YOU SHOULD CAREFULLY CONSIDER THE RISK FACTORS RELATING TO THE MERGER, WHICH ARE
DESCRIBED BEGINNING ON PAGE [  ].

       NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THE PARK COMMON SHARES TO BE ISSUED IN
CONNECTION WITH THE MERGER OR DETERMINED IF THIS JOINT PROXY
STATEMENT/PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY
IS A CRIMINAL OFFENSE.

       This joint proxy statement/prospectus is dated [      ], 2001 and is
first being mailed to shareholders of Park and of Security on or about [      ],
2001.


<PAGE>   7


                      REFERENCES TO ADDITIONAL INFORMATION

       This joint proxy statement/prospectus incorporates important business and
financial information about Park and Security from documents that Park and
Security have filed with the Securities and Exchange Commission, but have not
included or delivered with this joint proxy statement/prospectus. This
information is available to you without charge upon your written or oral
request. You can obtain documents related to Park and Security that are
incorporated by reference into this joint proxy statement/prospectus by
requesting them in writing or by telephone from the appropriate corporation:

<TABLE>
<S>                                                            <C>
       Park National Corporation                               Security Banc Corporation
       50 North Third Street                                   40 South Limestone Street
       P.O. Box 3500                                           Springfield, Ohio  45502
       Newark, Ohio  43058-3500                                Attention: J. William Stapleton, Executive
       Attention:  David C. Bowers, Secretary                             Vice President and Secretary
       (740) 349-3708                                          (937) 324-6916
</TABLE>

       PLEASE REQUEST DOCUMENTS NO LATER THAN [     ], 2001 IN ORDER TO RECEIVE
THEM BEFORE THE SPECIAL meetings. If you request any documents, they will be
mailed to you by first class mail, or another equally prompt means, by the next
business day after your request is received.

       See "Where You Can Find More Information" on page [ ] for more
information about the documents referred to in this joint proxy
statement/prospectus.


<PAGE>   8


                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
Description                                                                                                    Page
-----------                                                                                                    ----

<S>                                                                                                           <C>
Questions and Answers About the Merger............................................................................1
Summary...........................................................................................................3
    Parties to the Merger.........................................................................................3
        Park National Corporation.................................................................................3
        Security Banc Corporation.................................................................................4
    Park Special Meeting..........................................................................................4
    Security Special Meeting......................................................................................5
    The Merger....................................................................................................5
        Reasons for the Merger....................................................................................5
        Opinion of Austin Associates, Inc.........................................................................6
        Exchange of Security Common Shares........................................................................6
        Fractional Shares.........................................................................................7
        Exchange of Security Certificates.........................................................................7
        Accounting Treatment......................................................................................7
        Federal Income Tax Consequences...........................................................................7
        Interests of Persons in the Merger........................................................................8
        Resale of Park Common Shares..............................................................................8
        Regulatory Approvals......................................................................................9
    The Merger Agreement..........................................................................................9
        Representations and Warranties; Covenants.................................................................9
        Conditions; Effective Time................................................................................9
        Amendment and Termination.................................................................................9
        Recommendations of the Boards of Directors of Park and Security..........................................10
        Treatment of Security Stock Options......................................................................10
    Rights of Dissenting Shareholders............................................................................10
    Comparison of Rights of Holders of Park Common Shares and of Security Common Shares..........................11
    Historical and Pro Forma Comparative Unaudited Per Share Data................................................11
    Selected Financial Data......................................................................................12
        Park Unaudited Selected Financial Data...................................................................13
        Security Unaudited Selected Financial Data...............................................................14
        Unaudited Pro Forma Combined Selected Financial Data.....................................................15
Risk Factors.....................................................................................................16
The Park Special Meeting.........................................................................................17
    Matters to be Considered at the Park Special Meeting.........................................................17
    Voting at the Park Special Meeting; Park Record Date.........................................................17
The Security Special Meeting.....................................................................................18
    Matters to be Considered at the Security Special Meeting.....................................................18
    Voting at the Security Special Meeting; Security Record Date.................................................18
Principal Shareholders of Park...................................................................................19
Principal Shareholders of Security...............................................................................22
The Merger.......................................................................................................24
    Background...................................................................................................25
    Reasons for the Merger.......................................................................................28
    Opinion of Austin Associates, Inc............................................................................30
        Summary of Financial Terms of Merger.....................................................................32
        Industry Comparative Analysis............................................................................33
        Comparable Transaction Analysis..........................................................................34
        Contribution Analysis....................................................................................34
        Pro Forma Merger Analysis................................................................................35
        Pro Forma Equivalent Dividends...........................................................................35
        Additional Limiting Conditions...........................................................................35
</TABLE>


                                        i


<PAGE>   9


<TABLE>
<S>                                                                                                       <C>
    Effect on Outstanding Park Common Shares and Exchange of Security Common Shares..............................36
        Effect on Outstanding Park Common Shares.................................................................36
        Exchange of Security Common Shares.......................................................................36
        No Fractional Park Common Shares to Be Issued............................................................37
        Closing of Security Share Transfer Books; Exchange of Certificates Evidencing Security Common Shares.....37
        Rights of Holders of Security Share Certificates Prior to Surrender......................................37
        Lost Share Certificates..................................................................................37
        Treatment of Outstanding Security Options................................................................37
    Accounting Treatment of the Merger...........................................................................38
    Federal Income Tax Consequences of the Merger................................................................38
    Interests of Persons in the Merger...........................................................................39
    Resale of Park Common Shares Received in the Merger..........................................................40
    Regulatory Approvals.........................................................................................41
    Existing Relationship between Park and Security..............................................................41
The Merger Agreement.............................................................................................41
    The Merger...................................................................................................41
    Conversion of Security Common Shares.........................................................................42
    Representations and Warranties...............................................................................42
    Conduct of Business Pending the Merger.......................................................................43
    Conditions to the Consummation of the Merger.................................................................47
    Effective Time of the Merger.................................................................................50
    Amendment and Termination....................................................................................50
    Acquisition Proposals........................................................................................52
        Security.................................................................................................52
        Park.....................................................................................................52
    Costs and Expenses; Indemnification..........................................................................53
    Recommendation and Vote......................................................................................53
Rights of Dissenting Shareholders................................................................................53
Unaudited Condensed Pro Forma Combined Financial Information.....................................................54
Business of Park.................................................................................................63
    General......................................................................................................63
    Additional Information.......................................................................................64
Management of Park...............................................................................................64
    Board of Directors...........................................................................................64
    Executive Officers...........................................................................................67
    Additional Information.......................................................................................67
Business of Security.............................................................................................67
    General......................................................................................................67
    Additional Information.......................................................................................68
Comparison of Rights of Holders of Park Common Shares and Holders of Security Common Shares......................69
    Authorized Capital Stock.....................................................................................69
    Composition of Board of Directors............................................................................69
    Classification...............................................................................................69
    Nominations..................................................................................................70
    Removal......................................................................................................70
    Mandatory Retirement.........................................................................................70
    Cumulative Voting............................................................................................70
    Special Voting Requirements..................................................................................71
    Amendments of Articles.......................................................................................72
    Amendments to the Regulations................................................................................72
    Calling a Special Meeting....................................................................................72
    Preemptive Rights............................................................................................72
    Dividends....................................................................................................73
    Anti-Takeover Statutes.......................................................................................73
        Ohio Control Share Acquisition Act.......................................................................73
</TABLE>


                                       ii


<PAGE>   10


<TABLE>
<S>                                                                                                      <C>
        Ohio Merger Moratorium Statute...........................................................................74
    Director and Officer Liability and Indemnification...........................................................74
Legal Matters....................................................................................................76
Experts..........................................................................................................76
    Park.........................................................................................................76
    Security.....................................................................................................76
Cautionary Statement Regarding Forward-Looking Information.......................................................76
Where You Can Find More Information..............................................................................77
    SEC Filings..................................................................................................77
    Registration Statement.......................................................................................78
    Documents Incorporated by Reference..........................................................................78
        Park Documents...........................................................................................78
        Security Documents.......................................................................................78


                                                 List of Appendices
                                                 ------------------

Appendix A          Agreement and Plan of Merger, dated as of November 20, 2000, between
                    Park National Corporation and Security Banc Corporation..............................       A-1
Appendix B          Opinion of Austin Associates, Inc....................................................       B-1
Appendix C          Ohio Revised Code Section 1701.85....................................................       C-1
</TABLE>


                                       iii


<PAGE>   11


                     QUESTIONS AND ANSWERS ABOUT THE MERGER


Q.     WHAT WILL SECURITY SHAREHOLDERS RECEIVE FOR THEIR SECURITY COMMON SHARES
       IN THE MERGER?

A.     When the merger is completed, Security shareholders will receive
       approximately .2844 Park common shares for each of their common shares of
       Security. Because the market price of the Park common shares may change
       from day to day, Security shareholders cannot be sure of the market value
       of the Park common shares they will receive in the merger at the time
       they vote their Security common shares. The closing price of a Park
       common share on November 20, 2000, the last trading day before the
       announcement of the signing of the merger agreement, was $91.375. The
       closing price of a Park common share on [      ], 2001, the last trading
       day before the date of this joint proxy statement/prospectus, was $[ ].

Q.     WHAT HAPPENS TO MY FUTURE DIVIDENDS?

A.     Security paid a quarterly dividend of $.20 per share on December 8, 2000
       to shareholders of record on November 30, 2000. Security plans to
       continue paying quarterly dividends at that rate on its common shares
       until the closing of the merger. Security and Park agreed in the merger
       agreement to cooperate to assure that during any applicable period, there
       will not be a payment of both a Park and a Security dividend to former
       Security shareholders as a result of the merger.

Q.     WHAT WILL HAPPEN IF THE SHAREHOLDERS OF PARK AND SECURITY DO NOT ADOPT
       THE MERGER AGREEMENT?

A.     If the merger agreement is not adopted by the shareholders of both Park
       and Security, management and the board of directors of each corporation
       will continue to operate Park and Security as before, and each
       corporation may consider other strategic alternatives. However, Security
       may be required to pay Park a termination fee of $10,000,000 if:

       -      Security terminates the merger agreement because it receives a
              proposal from another party to acquire Security; or

       -      the merger agreement is terminated for a different reason and
              Security enters into an agreement with another party to sell
              Security within one year from the date of termination of the
              merger agreement.

Q.     WHAT DO I NEED TO DO NOW?

A.     After you have carefully read this document, please indicate on your
       proxy card how you want to vote. Sign and date the proxy card and mail it
       in the enclosed prepaid return envelope marked "Proxy" as soon as
       possible, so that your common shares may be represented and voted at the
       Park special meeting or the Security special meeting, as appropriate.

       In order for us to complete the merger, the holders of at least
       two-thirds of the issued and outstanding Park common shares and the
       holders of at least two-thirds of the issued and outstanding Security
       common shares must vote to adopt the merger agreement. THE BOARDS OF
       DIRECTORS OF PARK AND SECURITY UNANIMOUSLY RECOMMEND VOTING "FOR" THE
       ADOPTION OF THE MERGER AGREEMENT.

Q.     WHAT HAPPENS IF I DO NOT SEND IN MY PROXY CARD, IF I DO NOT INSTRUCT MY
       BROKER TO VOTE MY COMMON SHARES, OR IF I ABSTAIN FROM VOTING?

A.     If you do not send in your proxy card, if you do not instruct your broker
       to vote your common shares, or if you abstain from voting, it will have
       the same effect as a vote "against" adoption of the merger agreement.


                                        1


<PAGE>   12


Q.     IF MY BROKER HOLDS MY COMMON SHARES IN "STREET NAME," WILL MY BROKER VOTE
       MY COMMON SHARES FOR ME?

A.     Your broker cannot vote your common shares without specific instructions
       from you. Unless you follow the directions your broker provides to you
       regarding how to instruct your broker to vote your common shares, your
       common shares will not be voted.

Q.     CAN I CHANGE MY VOTE AFTER I HAVE MAILED MY SIGNED PROXY CARD?

A.     Yes. You can change your vote at any time before your proxy is voted at
       the Park special meeting or the Security special meeting, as appropriate.
       Just send in a later-dated, signed proxy card or a written notice of
       revocation to the person to whom you submitted your proxy card before the
       appropriate special meeting. You can also change your vote by attending
       the appropriate special meeting and voting in person. Your attendance at
       the special meeting alone will not revoke your proxy. If you have
       instructed your broker to vote your common shares, you must follow the
       directions received from your broker to change those instructions.

Q.     WHEN DO YOU EXPECT TO COMPLETE THE MERGER?

A.     Park and Security are working toward completing the merger during the
       second quarter of 2001. We anticipate completing the merger shortly after
       the special meetings are held, assuming that the shareholders of both
       Park and Security adopt the merger agreement.

Q.     WHERE CAN I FIND MORE INFORMATION ABOUT THE FILINGS PARK AND SECURITY
       MAKE WITH THE SEC?

A.     Park and Security file reports and other information with the SEC. You
       may read and copy this information at the SEC's public reference
       facilities. Please call the SEC at 1-800-SEC-0330 for information about
       these facilities. This information is also available on the Internet site
       the SEC maintains at www.sec.gov. Information regarding Park is available
       on the Internet site Park maintains at www.parknationalcorp.com and at
       the offices of the American Stock Exchange. You can also request copies
       of the filings made with the SEC from Park or Security.

Q.     WHO CAN ANSWER ANY OTHER QUESTIONS I MAY HAVE?

A.     If you have questions, you may contact Park and Security at:

<TABLE>
<S>                                                               <C>
                Park National Corporation                         Security Banc Corporation
                50 North Third Street                             40 South Limestone Street
                P.O. Box 3500                                     Springfield, Ohio  45502
                Newark, Ohio  43058-3500                          Attention:  J. William Stapleton, Executive
                Attention: David C. Bowers, Secretary                         Vice President and Secretary
                (740) 349-3708                                    (937) 324-6916
</TABLE>


                                        2


<PAGE>   13


                                     SUMMARY

       This summary highlights selected information from this joint proxy
statement/prospectus. It does not contain all of the information that you may
consider important. We urge you to read carefully the entire document and the
other documents referred to in this joint proxy statement/prospectus to fully
understand the proposed merger. Each item in this summary includes a page
reference directing you to a more complete description of that item.

       We propose a merger between Park and Security. If the holders of at least
two-thirds of the issued and outstanding Park common shares and the holders of
at least two-thirds of the issued and outstanding Security common shares adopt
the merger agreement, and if all other conditions to the consummation of the
merger are satisfied, Security will merge into Park. As a result, Security's
subsidiaries, Security National Bank and Trust Company, The Citizens National
Bank of Urbana and The Third Savings and Loan Company, will become wholly-owned
subsidiaries of Park. Park will continue its corporate existence under Ohio law
as the surviving corporation of the merger.

PARTIES TO THE MERGER

PARK NATIONAL CORPORATION (SEE PAGE [    ])
50 North Third Street
P.O. Box 3500
Newark, Ohio  43058-3500
(740) 349-8451

       Park is an Ohio corporation registered as a bank holding company under
the Bank Holding Company Act of 1956, and subject to regulation by the Board of
Governors of the Federal Reserve System.

       Through its banking subsidiaries, The Park National Bank, Newark, Ohio, a
national banking association; The Richland Trust Company, Mansfield, Ohio, an
Ohio state-chartered bank; Century National Bank, Zanesville, Ohio, a national
banking association; The First-Knox National Bank of Mount Vernon, a national
banking association; United Bank, N.A., Bucyrus, Ohio, a national banking
association; and Second National Bank, Greenville, Ohio, a national banking
association, Park is engaged in a general commercial banking and trust business
in small to medium population Ohio communities. In early 1999, Park organized
Guardian Financial Services Company, an Ohio consumer finance company based in
Hilliard, Ohio. Park's subsidiaries operate 77 full-service offices and a
network of 80 automatic teller machines in 20 central and southern Ohio
counties.

       Park National Bank is further divided into two banking divisions with the
Park National Division headquartered in Newark, Ohio and the Fairfield National
Division headquartered in Lancaster, Ohio. First-Knox National Bank is similarly
divided into two banking divisions with the First-Knox National Division
headquartered in Mount Vernon, Ohio and the Farmers and Savings Division
headquartered in Loudonville, Ohio.

       As of September 30, 2000, Park had total consolidated assets of
approximately $3.2 billion, total consolidated deposits of approximately $2.4
billion and total consolidated shareholders' equity of approximately $308
million.


                                        3


<PAGE>   14


SECURITY BANC CORPORATION (SEE PAGE [     ])
40 South Limestone Street
Springfield, Ohio  45502
(937) 324-6920

       Security, headquartered in Springfield, Ohio, is an Ohio corporation
registered in 1985 as a bank holding company under the Bank Holding Company Act
and subject to regulation by the Federal Reserve Board. Security has three
subsidiaries, Security National Bank and Trust Company, Springfield, Ohio, a
national banking association; The Citizens National Bank of Urbana, Urbana,
Ohio, a national banking association; and The Third Savings and Loan Company,
Piqua, Ohio, an Ohio state-chartered savings association.

       Security had total consolidated assets of approximately $1.0 billion,
total consolidated deposits of approximately $724 million and total consolidated
shareholders' equity of approximately $123 million as of September 30, 2000.

       Through its subsidiaries, Security offers a broad range of banking
services to the commercial, industrial and consumer market segments which it
serves. Services include commercial, real estate and personal loans; checking,
savings and time deposits; and other customer services such as safe deposit
facilities. Security does not have any foreign operations, assets or
investments.

PARK SPECIAL MEETING (SEE PAGE [    ])

       Park will hold a special meeting of shareholders on [     ], [     ],
2001, at [ ]:00 [_.M.], local time, at the offices of The Park National Bank, 50
North Third Street, Newark, Ohio. Only the holders of record of the issued and
outstanding Park common shares at the close of business on [    ], 2001 will be
entitled to notice of, and to vote at, the Park special meeting and any
adjournment of the Park special meeting. As of the record date, there were
10,783,682 Park common shares issued and outstanding, each of which will be
entitled to one vote on each matter properly submitted for vote to the
shareholders at the Park special meeting.

       At the Park special meeting, Park will ask the Park shareholders to
consider and vote upon:

       -      a proposal to adopt the merger agreement and

       -      the transaction of any other business that properly comes before
              the Park special meeting or any adjournment of the Park special
              meeting.

       The affirmative vote of the holders of at least two-thirds of the issued
and outstanding Park common shares, voting in person or by proxy, is required to
adopt the merger agreement. If a Park shareholder abstains from voting or fails
to return a properly executed proxy card, the effect will be a vote "AGAINST"
adoption of the merger agreement. As of December 15, 2000, the directors and
executive officers of Park (16 individuals) and their respective affiliates in
the aggregate beneficially owned 1,801,032 Park common shares (excluding those
subject to currently exercisable options), or 16.7% of the outstanding Park
common shares.

       If a Park shareholder returns a properly executed proxy card prior to the
Park special meeting and does not revoke the proxy prior to its use, the Park
common shares represented by that proxy card will be voted at the Park special
meeting, or any adjournment of the Park special meeting. The Park common shares
will be voted as specified on the proxy card or, in the absence of specific
instructions to the contrary, will be voted "FOR" adoption of the merger
agreement.

       If a Park shareholder returns a proxy card which has been voted "AGAINST"
adoption of the merger agreement, that proxy will not be used to vote to adjourn
the special meeting so that Park may solicit further support for adoption of the
merger agreement.


                                        4


<PAGE>   15


SECURITY SPECIAL MEETING (SEE PAGE [    ])

       Security will hold a special meeting of shareholders on [     ], [     ],
2001, at [  ]:00 [_.M.], local time, at [                        ], Ohio. Only
the holders of record of the issued and outstanding Security common shares at
the close of business on [      ], 2001 will be entitled to notice of, and to
vote at, the Security special meeting and any adjournment of the Security
special meeting. As of the record date, there were 11,777,700 Security common
shares issued and outstanding, each of which will be entitled to one vote on
each matter properly submitted for vote to the shareholders at the Security
special meeting.

       At the Security special meeting, Security will ask the Security
shareholders to consider and vote upon:

       -      a proposal to adopt the merger agreement and

       -      the transaction of any other business that properly comes before
              the Security special meeting or any adjournment of the Security
              special meeting.

       The affirmative vote of the holders of at least two-thirds of the issued
and outstanding Security common shares, voting in person or by proxy, is
required to adopt the merger agreement. If a Security shareholder abstains from
voting or fails to return a properly executed proxy card, the effect will be a
vote "AGAINST" adoption of the merger agreement. As of December 15, 2000, the
directors and executive officers of Security (13 individuals) and their
respective affiliates in the aggregate beneficially owned 403,573 Security
common shares (excluding those subject to currently exercisable options), or
3.4% of the outstanding Security common shares.

       If a Security shareholder returns a properly executed proxy card prior to
the Security special meeting and does not revoke the proxy prior to its use, the
Security common shares represented by that proxy card will be voted at the
Security special meeting, or any adjournment of the Security special meeting.
The Security common shares will be voted as specified on the proxy card or, in
the absence of specific instructions to the contrary, will be voted "FOR"
adoption of the merger agreement.

       If a Security shareholder returns a proxy card which has been voted
"AGAINST" adoption of the merger agreement, that proxy will not be used to vote
to adjourn the Security special meeting so that Security may solicit further
support for adoption of the merger agreement.

THE MERGER (SEE PAGE [    ])

REASONS FOR THE MERGER (SEE PAGE [    ])

       The board of directors of Security believes that the merger with Park is
fair and in the best interests of Security and its shareholders. In negotiating
the terms of the merger, management of Security considered a number of factors
with a view to maximizing shareholder value in the intermediate and long term,
including:

       -      the opinion of Austin Associates, Inc. that the exchange ratio
              provided for in the merger agreement was fair to Security
              shareholders from a financial point of view;

       -      the overall financial terms of the merger;

       -      current long-term industry developments and trends;

       -      competitive factors;

       -      the business and financial condition and earnings prospects of
              Park;

       -      the competence, experience and integrity of Park's management;

       -      the adequacy of the consideration to be received by Security's
              shareholders in the merger;


                                        5


<PAGE>   16


       -      the historical trading prices of the Security common shares; and

       -      future prospects for Security.

       The board of directors of Park believes that the merger with Security is
fair and in the best interests of Park and its shareholders. In negotiating the
terms of the merger, management of Park considered a number of factors with a
view to maximizing shareholder value in the intermediate and long term,
including:

       -      the earnings potential of the combined business;

       -      the strengthened capital base of the combined business;

       -      the potential realization of economies of scale;

       -      the growth prospects within the existing market area of Security's
              subsidiaries; and

       -      expansion of the community banking model successfully employed by
              Park.

OPINION OF AUSTIN ASSOCIATES, INC.  (SEE PAGE [    ])

       Security's financial advisor, Austin Associates, Inc., has delivered its
written opinion to the board of directors of Security to the effect that, as of
November 20, 2000, the financial terms of Park's offer to acquire Security were
fair to Security and its shareholders. A copy of the Austin Associates opinion
letter is attached as Appendix B. You should read the opinion letter in its
entirety for a description of the procedures followed, assumptions and
qualifications made and matters considered by Austin Associates, as well as for
a description of the limitations of the opinion.

EXCHANGE OF SECURITY COMMON SHARES (SEE PAGE [     ])

       At the effective time of the merger, all Security common shares that are
held by Security as treasury shares, will be canceled and retired and no Park
common shares or other consideration will be delivered in exchange for those
Security common shares. Any Security common shares owned by Park will become
treasury shares of Park after the merger. As of the date of this joint proxy
statement/prospectus, Park directly owned 15,000 Security common shares. All of
the remaining issued and outstanding Security common shares, other than those as
to which the holders have properly exercised dissenter's rights, will be
converted into a number of Park common shares equal to an exchange ratio
described in the merger agreement. The exchange ratio will be determined by
dividing 3,350,000 by the number of Security common shares outstanding
immediately prior to the effective time of the merger. On [      ], 2001, there
were [11,777,700] Security common shares issued and outstanding. Based on this,
the exchange ratio will equal approximately .2844, calculated by dividing
3,350,000 by [11,777,700].

         The Park common shares are listed on the American Stock Exchange, under
the symbol "PRK". The Security common shares are traded on the over-the-counter
market, under the symbol "STYB". The following table sets forth the high and low
sales prices on the American Stock Exchange of Park common shares on November
20, 2000 and the bid and ask prices reported on the over-the-counter market of
Security common shares on November 20, 2000, the last trading day prior to the
joint public announcement by Park and Security of the signing of the merger
agreement. The table also sets forth the equivalent per share basis of Security
common shares, calculated by multiplying the high and low sales prices of Park
common shares on November 20, 2000 by the assumed exchange ratio of .2844.


                                        6


<PAGE>   17


<TABLE>
<S>                                                         <C>
       Sales prices on November 20, 2000
       for Park common shares:
              High...................................         $ 92.25
              Low....................................         $ 90.00
       Prices on November 20, 2000 for Security
       common shares:
              Bid....................................         $ 18.00
              Ask....................................         $ 17.50
       Equivalent per share basis:
              High...................................         $ 26.24
              Low....................................         $ 25.60
</TABLE>

       OF COURSE, THE MARKET PRICE OF THE PARK COMMON SHARES WILL FLUCTUATE
PRIOR TO THE MERGER. PARK AND SECURITY ENCOURAGE YOU TO OBTAIN CURRENT MARKET
QUOTATIONS FOR THE PARK COMMON SHARES.

       Park will file an application to list the Park common shares to be issued
in the merger for trading on the American Stock Exchange.

FRACTIONAL SHARES (SEE PAGE [    ])

       Park will not issue fractional common shares in the merger. In lieu of
fractional shares, Park will pay to each holder of Security common shares who
otherwise would be entitled to receive a fraction of a Park common share, an
amount in cash, rounded to the nearest cent, determined by multiplying the
fractional share interest by the market value of a Park common share. The market
value of a Park common share will equal the average closing sale price of a Park
common share for the 20 trading days immediately preceding the tenth day prior
to the effective time of the merger, as reported on the American Stock Exchange.

EXCHANGE OF SECURITY CERTIFICATES (SEE PAGE [    ])

       As soon as reasonably practicable after the consummation of the merger,
First-Knox National Bank, exchange agent for the merger, will advise each
Security shareholder of the merger by letter of transmittal accompanied by
instructions for surrendering the certificate or certificates evidencing the
shareholder's Security common shares to the exchange agent. CERTIFICATES FOR
SECURITY COMMON SHARES SHOULD NOT BE SENT TO FIRST-KNOX NATIONAL BANK UNTIL
AFTER RECEIPT OF THE LETTER OF TRANSMITTAL AND SHOULD NOT BE RETURNED TO
SECURITY WITH THE ENCLOSED PROXY CARD.

ACCOUNTING TREATMENT (SEE PAGE [  ])

       The consummation of the merger is conditioned upon the availability of
the pooling-of-interests method of accounting for the merger.
"Pooling-of-interests" means that, for accounting and financial reporting
purposes, Park and Security will be treated as if they had always been one
combined entity. If the holders of more than 10% of the common shares of either
Park or Security exercise their rights to dissent to the merger, Park may not be
able to utilize the pooling-of-interests method of accounting for the merger.
Because pooling-of-interests accounting is a condition to the merger, the
unavailability of this method could result in the termination of the merger
agreement.

FEDERAL INCOME TAX CONSEQUENCES (SEE PAGE [  ])

       The consummation of the merger is conditioned upon receipt of the opinion
of Vorys, Sater, Seymour and Pease LLP, legal counsel to Park, to the effect
that the merger will constitute a tax-free reorganization under Section 368(a)
of the Internal Revenue Code of 1986. Security shareholders will not recognize a
gain or loss upon the issuance of Park common shares to them. A gain or loss
will be recognized, however, in respect of cash received upon the exercise of
dissenters' rights by Park shareholders or by Security shareholders. A gain or
loss will also be


                                        7


<PAGE>   18


recognized by Security shareholders with respect to any cash received in lieu of
fractional shares. Neither the opinion of counsel nor the discussion of federal
income tax consequences in this joint proxy statement/prospectus is binding upon
either the Internal Revenue Service or the courts. You should consult your own
tax advisor for a full understanding of the tax consequences of the merger.

INTERESTS OF PERSONS IN THE MERGER (SEE PAGE [  ])

       Park has agreed to indemnify each of the officers, directors and
employees of Security and each Security subsidiary to the full extent Security
or any Security subsidiary would have been required to indemnify that individual
under Ohio law and the governing documents of Security and Security's
subsidiaries. The merger agreement also provides for the continuation of
director and officer liability insurance for the directors and officers of
Security and each of Security's subsidiaries for a period of three years,
following the effective time of the merger.

       In addition, Park will ensure that participants in Security's split
dollar insurance benefit program will continue to receive the vested portion of
their death benefits following the completion of the merger. Also, if Park
ceases to maintain Security's pension plan, Park has agreed to provide
participants in the Security pension plan who become participants in the Park
pension plan with the same accrued benefits that they have earned under the
Security pension plan.

       Security National Bank, a subsidiary of Security, has entered into
employment agreements with three of its executive officers, Harry O. Egger, J.
William Stapleton and William C. Fralick. The employment agreements provide
these individuals with severance benefits and accelerated vesting of benefits
under benefit plans if their employment with Security National Bank is
terminated without cause within one year of a change in control of Security. The
employment agreements also provide for the payment of benefits in the event that
the employee's employment is terminated without cause or as the result of
disability or death. Third Savings, another subsidiary of Security, has entered
into a similar agreement with Scott A. Gabriel, one of its executive officers.
Citizens National Bank, another subsidiary of Security, has entered into a
similar employment agreement with James R. Wilson, one of its executive
officers. Under the terms of another agreement between Mr. Wilson and Citizens
National Bank, Mr. Wilson (or in the event of his death, his wife) is entitled
to receive annual cash payments for a period of ten years following his
retirement or death.

       All of the individuals who have entered into employment agreements with a
subsidiary of Security are also executive officers of Security. Messrs. Egger,
Gabriel and Wilson also serve as directors of Security.

       Each option to purchase Security common shares that is outstanding
immediately before the merger is completed will be converted into an option to
buy Park common shares. The number of Park common shares subject to each
converted option, as well as the exercise price of that option, will be adjusted
to reflect the exchange ratio. As of the date of this joint proxy
statement/prospectus, the directors and executive officers of Security held
in-the-money options covering an aggregate of 36,400 Security common shares with
exercise prices of $16.50.

RESALE OF PARK COMMON SHARES (SEE PAGE [  ])

       The Park common shares to be issued upon consummation of the merger have
been registered with the SEC under the Securities Act and will be freely
transferable. However, common shares of Park received by any person who is
deemed to be an "affiliate" (as that term is defined under the Securities Act of
1933) of Security prior to the merger or of Park after the merger may be resold
by that person only in compliance with the volume and manner-of-sale
requirements of Rules 144 and 145 under the Securities Act. Affiliates of Park
will be governed by the additional provisions of Rule 144. Affiliates of
Security or Park generally include individuals or entities that control, are
controlled by, or are under common control with, that corporation and may
include certain officers and directors of that corporation as well as principal
shareholders of that corporation. In addition, Security has obtained customary
agreements with all directors, officers and affiliates of Security under which
those persons have agreed not to dispose of their Park common shares in a manner
that would adversely affect the ability of Park to treat the merger as a
pooling-of-interests for financial accounting purposes.


                                        8


<PAGE>   19


REGULATORY APPROVALS (SEE PAGE [  ])

       Consummation of the merger is subject to prior receipt by Park and
Security of all necessary regulatory approvals. The principal regulatory
approval required to be obtained is from the Federal Reserve Board. A bank
holding company merger application was filed with the Federal Reserve Board on
January 2, 2001. The required notice filing with the Office of Thrift
Supervision will be made in accordance with the regulations of the OTS.

THE MERGER AGREEMENT (SEE PAGE [       ])

REPRESENTATIONS AND WARRANTIES; COVENANTS (SEE PAGE [      ])

       In the merger agreement, Park and Security each have made representations
and warranties to the other. In addition, Park and Security each have made
covenants, including covenants related to the conduct of business between the
date of the merger agreement and the effective time of the merger.

CONDITIONS; EFFECTIVE TIME (SEE PAGES [      ] AND [      ])

         The consummation of the merger is subject to satisfaction or waiver of
a number of conditions. These include:

       -      adoption of the merger agreement by Park shareholders and by
              Security shareholders;

       -      absence of any legal prohibitions against the merger;

       -      material compliance by Park and Security with their obligations
              under the merger agreement;

       -      receipt of all required regulatory approvals and expiration of all
              applicable waiting periods;

       -      in the aggregate, less than 10% of the total number of common
              shares to be issued by Park in the merger are:

              -      the subject of dissenters' rights exercised by Park or
                     Security shareholders, or

              -      subject to purchase as fractional Park shares;

       -      the truth and correctness of the representations and warranties of
              Park and Security in all material respects; and

       -      listing of the Park common shares to be issued in the merger on
              the American Stock Exchange.

       Where the law permits, either Park or Security could choose to waive a
condition to its obligation to complete the merger even when that condition has
not been satisfied. As soon as possible after the satisfaction or waiver of all
conditions, Park and Security will cause a certificate of merger to be filed
with the Ohio Secretary of State. Park and Security currently anticipate that
the merger will be completed during the second quarter of 2001.

AMENDMENT AND TERMINATION  (SEE PAGE [      ])

       Park and Security may agree in writing to amend or terminate the merger
agreement at any time without completing the merger, even after their respective
shareholders have approved it. Security also may decide not to proceed with the
merger if the average closing sale price of a Park common share, for the 20
trading day period immediately preceding the tenth day prior to the effective
time of the merger, is less than $77.50 and if the ratio of the price decline
for Park common shares exceeds the ratio of the price decline for shares of the
common stock of a specific group of bank holding companies. In addition, either
Security or Park may decide to terminate the merger agreement:


                                        9


<PAGE>   20


       -      upon specified breaches by the other party;

       -      if the merger has not been completed by October 31, 2001;

       -      if a regulatory authority fails to approve the merger; or

       -      upon the occurrence or the failure to occur of other conditions
              described in the merger agreement and described in greater detail
              later in this joint proxy statement/prospectus.

       Under specific circumstances, if the merger is not completed, Security
could be required to pay a special fee to Park. In the merger agreement,
Security has agreed not to solicit or encourage the submission of any other
acquisition proposal by a third party. However, the board of directors of
Security is not prohibited from taking any action which is necessary in the
exercise of its fiduciary duties. If the merger is not completed because of
another possible acquisition involving Security, the merger agreement may
require Security to pay a $10,000,000 special fee to Park. If the merger
agreement is terminated for a different reason and Security enters into an
agreement to sell Security to another party within one year, then Security may
be required to pay a $10,000,000 special fee to Park under specified
circumstances. This $10,000,000 fee could discourage other companies from trying
to acquire Security before the merger.

       Additionally, Park has agreed not to accept any acquisition proposal by a
third party unless the third party agrees to the perform Park's obligations
under the merger agreement. This could discourage other companies from trying to
acquire Park before the merger.

RECOMMENDATIONS OF THE BOARDS OF DIRECTORS OF PARK AND SECURITY (SEE PAGE [   ])

       The boards of directors of Park and Security both believe that
consummation of the proposed merger is in the best interest of their respective
corporations and shareholders. Accordingly, the boards of directors of Park and
Security recommend that their respective shareholders vote "FOR" adoption of the
merger agreement.

TREATMENT OF SECURITY STOCK OPTIONS (SEE PAGE [   ])

       Each option to buy Security common shares that is outstanding and not yet
exercised immediately before the merger is completed will be converted into an
option to buy Park common shares. The number of Park common shares subject to
each converted option, as well as the exercise price of that option, will be
adjusted to reflect the exchange ratio. The other terms of each converted option
will be substantially the same as those of the original Security option.

RIGHTS OF DISSENTING SHAREHOLDERS (SEE PAGE [     ])

       Any shareholder of either Park or Security who does not vote in favor of
adoption of the merger agreement and who delivers a written demand for payment
of the fair cash value of the shareholder's common shares in the manner provided
by Section 1701.85 of the Ohio Revised Code will be entitled, if and when the
merger is consummated and upon strict compliance with the procedures described
in Section 1701.85, to receive the fair cash value of the shareholder's common
shares. A copy of Section 1701.85 is attached as Appendix C to this document. If
you are a Security shareholder, the amount of cash you will receive if you
exercise your dissenters' rights may be equal to, more than or less than the
value of the Park common shares you would otherwise receive in the merger. If
you are a Park shareholder and you wish to submit a written demand for payment
of the fair cash value of your Park common shares, you must deliver such notice
by [      ], 2001 to Park National Corporation, 50 North Third Street, Newark,
Ohio 43055, Attention: David C. Bowers, Secretary. If you are a Security
shareholder and you wish to submit a written demand for payment of the fair cash
value of your Security common shares, you must deliver such notice by [       ],
2001 to Security Banc Corporation, 40 South Limestone Street, Springfield, Ohio
45502, Attention: J. William Stapleton, Executive Vice President and Secretary.
Completion of the merger is subject to the condition that, in the aggregate,
less than 10% of the number of Park common shares to be issued in the merger are
subject to purchase as fractional Park common shares or the subject of
dissenters' rights exercised by shareholders of Park and Security.


                                       10


<PAGE>   21


COMPARISON OF RIGHTS OF HOLDERS OF PARK COMMON SHARES AND OF SECURITY COMMON
SHARES (SEE PAGE [     ])

       After the merger, Security shareholders will become shareholders of Park
and the articles and regulations of Park will govern their rights as
shareholders. Several differences exist between the articles and regulations of
Security and the articles and regulations of Park which affect the rights of the
shareholders of those corporations. Examples of differences include provisions
affecting the removal and nomination of directors, pre-emptive rights,
cumulative voting and voting on certain significant corporate transactions.
However, since Security and Park are both Ohio corporations, Ohio law will
continue to govern the rights of Security shareholders after the merger.

HISTORICAL AND PRO FORMA COMPARATIVE UNAUDITED PER SHARE DATA

       The following table shows historical information about Park's and
Security's earnings per common share, dividends per common share, book value per
common share and similar information reflecting the merger, which we refer to as
"pro forma" information. In presenting the comparative pro forma information for
the time periods shown, it is assumed that Park and Security were merged
throughout those periods.

       It is also assumed that Park and Security will be treated as if they had
always been combined for accounting and financial reporting purposes, a method
known as "pooling-of-interests" accounting. The information listed as
"equivalent pro forma" was obtained by multiplying pro forma amounts by the
exchange ratio of .2844.

       The information in the following table is based on, and you should read
it together with, the historical financial information that Park and Security
have presented in prior filings with the SEC. The pro forma information does not
necessarily reflect what the historical results of Park would have been had Park
and Security been combined during the periods presented. Park and Security are
incorporating the historical financial information included in their SEC filings
into this joint proxy statement/prospectus by reference. See "Where You Can Find
More Information" on page [  ] for a description of where you can find these
prior SEC filings.


                                       11


<PAGE>   22


<TABLE>
<CAPTION>
                                                  AS OF OR FOR THE                     AS OF OR FOR THE
                                                 NINE MONTHS ENDED                 YEARS ENDED DECEMBER 31,
                                                 SEPTEMBER 30, 2000             1999            1998          1997
                                            -----------------------------       ----            ----          ----

<S>                                                  <C>                      <C>             <C>           <C>
PARK NATIONAL CORPORATION

Basic earnings per common share:
   Historical                                        $  3.91                  $  4.30         $  4.31       $  3.93
   Pro forma                                            3.89                     4.45            4.36          3.99
Diluted earnings per common share:
   Historical                                           3.90                     4.28            4.28          3.91
   Pro forma                                            3.88                     4.43            4.33          3.97
Dividends declared on common shares:
   Historical                                           1.95                     2.36            1.94          1.60
   Pro forma                                            1.95                     2.36            1.94          1.60
Book value per common share:
   Historical                                          28.46                    26.63           26.31         24.46
   Pro forma                                           30.36                    28.55           28.20         26.15

SECURITY BANC CORPORATION

Basic earnings per common share:
   Historical                                           1.08                     1.40            1.29          1.20
   Equivalent pro forma                                 1.11                     1.27            1.24          1.13
Diluted earnings per common share:
   Historical                                           1.08                     1.39            1.28          1.19
   Equivalent pro forma                                 1.10                     1.26            1.23          1.13
Dividends declared on common shares:
   Historical                                           0.42                     0.55            0.50          0.45
   Equivalent pro forma                                 0.55                     0.67            0.55          0.46
Book value per common share:
   Historical                                          10.39                     9.85            9.71          8.96
   Equivalent pro forma                                 8.63                     8.12            8.02          7.44
</TABLE>

SELECTED FINANCIAL DATA

       The following tables present consolidated historical financial data for
Park and for Security. They also present similar pro forma information
reflecting the merger. The pro forma information reflects the
pooling-of-interests method of accounting.

       The information in the following tables is based on historical financial
information that Park and Security have presented in prior filings with the SEC.
The pro forma information does not necessarily reflect what the historical
results of Park would have been had Park and Security been combined during the
periods presented. You should read all of the summary financial information that
is provided in the following tables together with the historical financial
information contained in the SEC filings incorporated by reference in this joint
proxy statement/prospectus and the more detailed pro forma financial information
provided in this joint proxy statement/prospectus, which you can find beginning
on page [ ]. See "Where You Can Find More Information" on page [ ] for a
description of where you can find historical financial information included in
the SEC filings Park and Security have made.


                                       12


<PAGE>   23


                     PARK UNAUDITED SELECTED FINANCIAL DATA
                        (In thousands, except share data)



<TABLE>
<CAPTION>
                                    NINE MONTHS ENDED
                                      SEPTEMBER 30,                                  YEAR ENDED DECEMBER 31,
                                    2000          1999            1999          1998           1997          1996          1995
                                ---------------------------   ----------------------------------------------------------------------

<S>                             <C>           <C>             <C>           <C>            <C>           <C>          <C>
Interest income                 $   184,294   $   165,581     $   224,316   $   217,446    $   209,217   $   190,409  $   176,349
Interest expense                     81,006        67,295          91,554        93,868         90,779        81,963       76,950
Net interest income                 103,288        98,286         132,762       123,578        118,438       108,446       99,399
Provision for loan losses             5,850         5,419          11,269         6,978          7,284         5,383        5,563
Noninterest income                   22,366        19,800          23,564        26,455         22,535        18,464       17,676
Noninterest expense                  60,857        57,651          79,912        75,323         71,910        68,341       65,226
Income tax expense                   16,529        15,798          18,358        20,724         18,738        16,403       13,945
                                ---------------------------   ----------------------------------------------------------------------
Net income                      $    42,418   $    39,218     $    46,787   $    47,008    $    43,041   $    36,783  $    32,341
                                ===========================   ======================================================================

Earnings per share - basic      $      3.91   $      3.60     $      4.30   $      4.31    $      3.93   $      3.36  $      2.94
Earnings per share - diluted    $      3.90   $      3.59     $      4.28   $      4.28    $      3.91   $      3.34  $      2.93

Cash dividends declared per
   share                        $      1.95   $      1.71     $      2.36   $      1.94    $      1.60   $      1.38  $      1.19

Book value per share (period
   end)                         $     28.46   $     26.94     $     26.63   $     26.31    $     24.46   $     22.06  $     20.55

Average common shares
   outstanding - basic           10,846,778    10,879,079      10,878,045    10,902,374     10,964,198    10,946,085   10,997,563
Average common shares
   outstanding - diluted         10,881,216    10,931,166      10,934,203    10,970,913     11,021,886    10,999,492   11,042,272
Common shares outstanding
   (period end)                  10,806,593    10,870,590      10,892,408    10,862,356     10,962,602    10,941,463   10,835,253

Average balances:
Assets                          $ 3,147,636   $ 2,960,716     $ 2,995,648   $ 2,784,832    $ 2,614,951   $ 2,382,411  $ 2,233,343
Earning assets                    2,973,583     2,768,651       2,802,368     2,594,178      2,455,613     2,240,652    2,091,458
Deposits                          2,415,536     2,339,827       2,343,856     2,250,408      2,101,258     1,932,479    1,816,100
Short-term borrowings               264,154       288,713         310,544       209,335        177,631       141,813      157,754
Long-term debt                      147,995        17,958          17,714        24,976         51,973        46,797       33,413
Shareholders' equity                289,581       288,358         287,407       274,616        250,500       226,021      205,241

Period end balances:
Assets                          $ 3,212,184   $ 3,075,474     $ 3,133,363   $ 2,945,879    $ 2,697,763   $ 2,574,686  $ 2,340,211
Long-term debt                      181,677        17,088          16,993        23,402         39,140        62,740       33,415

Ratios:
Return on average assets              1.80%         1.77%           1.56%         1.69%          1.65%         1.54%        1.45%
Return on average equity             19.57%        18.18%          16.28%        17.12%         17.18%        16.27%       15.76%
</TABLE>


                                       13


<PAGE>   24


                   SECURITY UNAUDITED SELECTED FINANCIAL DATA
                        (In thousands, except share data)


<TABLE>
<CAPTION>
                                    NINE MONTHS ENDED
                                      SEPTEMBER 30,                                  YEAR ENDED DECEMBER 31,
                                    2000          1999            1999          1998           1997          1996          1995
                                ---------------------------   ----------------------------------------------------------------------

<S>                             <C>           <C>             <C>           <C>            <C>           <C>           <C>
Interest income                 $    54,706   $    51,128     $    68,718   $    64,034    $    62,778   $    51,891  $    49,706
Interest expense                     23,438        20,345          27,684        24,195         24,903        19,311       18,003
Net interest income                  31,268        30,783          41,034        39,839         37,875        32,580       31,703
Provision for loan losses             1,065           900           1,200         1,540          1,300         1,875          950
Noninterest income                    6,485         6,211           8,533         8,489          7,104         5,893        5,210
Noninterest expense                  17,428        17,237          23,548        22,974         22,729        18,021       18,079
Income tax expense                    6,347         6,175           7,801         8,194          6,462         5,190        5,177
                                ---------------------------   ----------------------------------------------------------------------
Net income                      $    12,913   $    12,682     $    17,018   $    15,620    $    14,488   $    13,387  $    12,707
                                ===========================   ======================================================================

Earnings per share - basic      $      1.08   $      1.04     $      1.40   $      1.29    $      1.20   $      1.11  $      1.06
Earnings per share - diluted    $      1.08   $      1.04     $      1.39   $      1.28    $      1.19   $      1.10  $      1.05

Cash dividends declared per
  share                         $      0.42   $      0.39     $      0.55   $      0.50    $      0.45   $      0.41  $      0.37

Book value per share (period
  end)                          $     10.39   $      9.85     $      9.85   $      9.71    $      8.96   $      8.33  $      7.50

Average common shares
  outstanding - basic            11,921,658    12,175,904      12,165,146    12,143,743     12,117,526    12,057,694   12,025,658
Average common shares
  outstanding - diluted          11,942,516    12,239,866      12,218,821    12,227,292     12,194,892    12,136,898   12,110,976
Common shares outstanding
  (period end)                   11,793,000    12,149,427      12,097,000    12,166,425     12,131,172    12,100,034   12,029,054

Average balances:
Assets                          $   957,740   $   947,639     $   954,953   $   846,472    $   829,305   $   698,254  $   652,302
Earning assets                      897,464       866,529         870,718       777,336        763,438       650,922      609,859
Deposits                            714,082       696,165         695,988       688,561        677,733       565,882      535,403
Short-term borrowings                42,364        29,712          36,305        37,738         40,290        33,187       27,996
Long-term debt                       92,933        95,395          96,147             -              -             -            -
Shareholders' equity                119,153       119,912         119,991       114,088        104,060        94,378       85,227

Period end balances:
Assets                          $   986,529   $   957,892     $   976,411   $   883,500    $   839,605   $   816,334  $   676,106
Long-term debt                      103,499        93,990          97,652             -              -             -            -

Ratios:
Return on average assets              1.79%         1.78%           1.78%         1.85%          1.75%         1.92%        1.95%
Return on average equity             14.45%        14.10%          14.18%        13.69%         13.92%        14.18%       14.91%
</TABLE>


                                       14


<PAGE>   25


              UNAUDITED PRO FORMA COMBINED SELECTED FINANCIAL DATA
                        (In thousands, except share data)



<TABLE>
<CAPTION>
                                    NINE MONTHS ENDED
                                      SEPTEMBER 30,                                  YEAR ENDED DECEMBER 31,
                                    2000          1999            1999          1998           1997          1996          1995
                                ---------------------------   ----------------------------------------------------------------------

<S>                             <C>           <C>             <C>           <C>            <C>           <C>          <C>
Interest income                 $   239,000   $   216,709     $   293,034   $   281,480    $   271,995   $   242,300  $   226,055
Interest expense                    104,444        87,640         119,238       118,063        115,682       101,274       94,953
Net interest income                 134,556       129,069         173,796       163,417        156,313       141,026      131,102
Provision for loan losses             6,915         6,319          12,469         8,518          8,584         7,258        6,513
Noninterest income                   28,851        26,011          32,097        34,944         29,639        24,357       22,886
Noninterest expense                  78,285        74,888         103,460        98,297         94,639        86,362       83,305
Income tax expense                   22,876        21,973          26,159        28,918         25,200        21,593       19,122
                                ---------------------------   ----------------------------------------------------------------------
Net income                      $    55,331   $    51,900     $    63,805   $    62,628    $    57,529   $    50,170  $    45,048
                                ===========================   ======================================================================

Earnings per share - basic      $      3.89   $      3.62     $      4.45   $      4.36    $      3.99   $      3.49  $      3.12
Earnings per share - diluted    $      3.88   $      3.60     $      4.43   $      4.33    $      3.97   $      3.47  $      3.11

Cash dividends declared per
  share                         $      1.95   $      1.71     $      2.36   $      1.94    $      1.60   $      1.38  $      1.19

Book value per share (period
  end)                          $     30.36   $     28.79     $     28.55   $     28.20    $     26.15   $     23.79  $     21.95

Average common shares
  outstanding - basic            14,235,876    14,341,906      14,337,813    14,356,055     14,410,422    14,375,293   14,417,660
Average common shares
  outstanding - diluted          14,276,246    14,412,184      14,409,236    14,448,355     14,490,113    14,451,226   14,486,634
Common shares outstanding
  (period end)                   14,156,256    14,325,887      14,332,795    14,322,487     14,412,707    14,382,713   14,256,316

Average balances:
Assets                          $ 4,105,285   $ 3,908,355     $ 3,950,601   $ 3,631,304    $ 3,444,256   $ 3,080,665  $ 2,885,645
Earning assets                    3,870,956     3,635,180       3,673,086     3,371,514      3,219,051     2,891,574    2,701,317
Deposits                          3,129,618     3,035,992       3,039,844     2,938,969      2,778,991     2,498,361    2,351,503
Short-term borrowings               306,518       318,425         346,849       247,073        217,921       175,000      185,750
Long-term debt                      240,928       113,353         113,861        24,976         51,973        46,797       33,413
Shareholders' equity                408,643       408,270         407,398       388,704        354,560       320,399      290,468

Period end balances:
Assets                          $ 4,198,439   $ 4,033,366     $ 4,109,774   $ 3,829,379    $ 3,537,368   $ 3,391,020    3,016,317
Long-term debt                      285,176       111,078         114,645        23,402         39,140        62,740       33,415

Ratios:
Return on average assets              1.80%         1.77%           1.62%         1.72%          1.67%         1.63%        1.56%
Return on average equity             18.10%        17.00%          15.66%        16.11%         16.23%        15.66%       15.51%
</TABLE>


                                       15


<PAGE>   26


                                  RISK FACTORS

       You should consider the following matters in deciding how to vote. You
also should consider the other information included or incorporated by reference
in this document.

SINCE THE MARKET PRICE OF THE PARK COMMON SHARES FLUCTUATES, SECURITY
SHAREHOLDERS CANNOT BE SURE OF THE MARKET VALUE OF THE PARK COMMON SHARES THEY
WILL RECEIVE IN THE MERGER.

       -      At the time the merger is completed, each Security common share
              will be converted into approximately .2844 Park common shares.
              This exchange ratio will not be adjusted in the event of any
              increase or decrease in the price of the Park common shares or the
              Security common shares. As a result, the value of the Park common
              shares received by Security shareholders in the merger may be
              higher or lower than the market value of the Park common shares at
              the time the Security shareholders vote on the merger agreement.
              Security may decide not to proceed with the merger if the average
              closing sale price of Park common shares, for the 20 trading day
              period immediately preceding the tenth day prior to the effective
              time of the merger, is less than $77.50 and if the ratio of the
              price decline for Park common shares exceeds the ratio of the
              price decline for shares of the common stock of a specific group
              of bank holding companies. Security, however, is not obligated to
              exercise this right and the parties could decide to proceed with
              the merger even if the average closing sale price of the Park
              common shares for that 20 day trading period is less than $77.50
              per share.

WE CANNOT ASSURE YOU THAT PARK AND SECURITY WILL SUCCESSFULLY INTEGRATE THEIR
BUSINESSES.

       -      Security has three subsidiaries, Security National Bank, Citizens
              National Bank and Third Savings. Park National currently intends
              to operate Security National Bank, Citizens National Bank and
              Third Savings as separate subsidiaries after the merger under
              their present management. The merger will nevertheless require
              some integration of the management and operations of corporations
              that have previously operated separately. This involves a number
              of risks, including the possible loss of key management personnel
              and additional demands on management resulting from the increase
              in the consolidated size of Park after the merger.

THE TERMINATION FEE MAY DISCOURAGE OTHER COMPANIES FROM TRYING TO ACQUIRE
SECURITY EVEN IF THE OTHER ACQUISITION COULD OFFER HIGHER IMMEDIATE VALUE TO
SECURITY SHAREHOLDERS.

       -      Security has agreed to pay Park a termination fee that could
              discourage other companies from trying to acquire Security. Other
              acquisitions might be superior to the merger with Park for the
              Security shareholders. If this termination fee were to be paid,
              Security would experience a negative impact on its financial
              condition and results of operations. This could discourage other
              companies from trying to acquire Security.

DIRECTORS AND EXECUTIVE OFFICERS OF SECURITY MAY HAVE INTERESTS THAT ARE
DIFFERENT FROM OR IN ADDITION TO THE INTERESTS OF OTHER SHAREHOLDERS OF
SECURITY.

       -      When considering the recommendations of the Security board of
              directors, Security shareholders should be aware that some members
              of the Security board of directors and some executive officers of
              Security may have interests in the merger that are different from,
              or in addition to, those of other Security shareholders. Some of
              these interests are described below.

       -      After the merger, Park will indemnify each of the officers,
              directors and employees of Security and each of the Security
              subsidiaries from and against specific liabilities arising out of
              the fact that the individual is or was an officer, director or
              employee of Security or any Security subsidiaries. The merger
              agreement also provides for the continuation of director and
              officer liability insurance for Security's directors and officers
              for a period of three years.


                                       16


<PAGE>   27


       -      Security's subsidiaries have entered into employment agreements
              with some of their executive officers. Many of these employment
              agreements provide that the executive officers will receive
              severance pay if they are discharged without cause within one year
              of a change of control of Security. The employment agreements also
              provide benefits if the executive officer is terminated without
              cause or as the result of disability or death. The executive
              officers who have entered into these employment agreements are
              also executive officers of Security and three are directors of
              Security.

PARK'S ACQUISITION STRATEGY COULD POSE RISKS IN THE FUTURE.

       -      Park has grown through acquisitions during recent years and
              anticipates that it will make additional acquisitions in the
              future. Park may need to issue additional Park common shares to
              pay for future acquisitions, which would further dilute the
              ownership interest of Park shareholders, including former Security
              shareholders. Future acquisitions also may require Park to use
              substantial cash or other liquid assets or to incur debt. If this
              occurs, Park may be more susceptible to economic downturns and
              competitive pressures.

                            THE PARK SPECIAL MEETING

       This joint proxy statement/prospectus is furnished to the shareholders of
Park in connection with the solicitation on behalf of the board of directors of
Park of proxies for use at the Park special meeting to be held at the offices of
The Park National Bank, 50 North Third Street, Newark, Ohio, on [    ], [    ],
2001 at [  ]:00 [_.M.], local time, or any adjournment of the Park special
meeting. This joint proxy statement/prospectus and the accompanying form of
proxy card were first mailed to Park shareholders on or about [      ], 2001.

MATTERS TO BE CONSIDERED AT THE PARK SPECIAL MEETING

       At the Park special meeting, Park shareholders will be asked to consider
and vote upon the adoption of the merger agreement. Park shareholders also will
consider and vote upon any other business which properly comes before the Park
special meeting.

       The Park board of directors has unanimously approved the merger agreement
and recommends that the Park shareholders vote "for" adoption of the merger
agreement.

VOTING AT THE PARK SPECIAL MEETING; PARK RECORD DATE

       Only holders of record of Park common shares at the close of business on
[      ], 2001 will be entitled to notice of, and to vote at, the Park special
meeting. As of that date, there were [      ] Park common shares issued and
outstanding. Each Park common share entitles the holder to one vote on each
matter to be submitted to the Park shareholders at the Park special meeting. A
majority of the issued and outstanding Park common shares constitutes a quorum
for the Park special meeting.

       Park common shares represented by signed proxy cards or voting
instructions that are returned to Park will be counted toward the quorum in all
matters even though they are marked as "abstain" or "against" or they are not
marked at all. Broker non-votes will also count toward the establishment of a
quorum. BECAUSE THE AFFIRMATIVE VOTE OF THE HOLDERS OF AT LEAST TWO-THIRDS OF
THE ISSUED AND OUTSTANDING PARK COMMON SHARES IS REQUIRED TO ADOPT THE MERGER
AGREEMENT, THE EFFECT OF AN ABSTENTION OR BROKER NON-VOTE IS THE SAME AS A "NO"
VOTE.

       If a Park shareholder properly signs and returns the accompanying proxy
card to Park prior to the Park special meeting and does not revoke it, the proxy
will be voted in accordance with the instructions contained on the card. If a
Park shareholder does not give any instructions, the individuals designated as
proxies in the accompanying proxy card will vote "FOR" adoption of the merger
agreement. In that event, the Park shareholder will not have the right to
dissent from the merger and demand payment of the "fair cash value" of that
shareholder's Park common shares.


                                       17


<PAGE>   28


       THE PROXIES OF THE PARK BOARD OF DIRECTORS MAY NOT VOTE PARK COMMON
SHARES REPRESENTED BY A PROXY CARD WHICH HAVE BEEN VOTED "AGAINST" ADOPTION OF
THE MERGER AGREEMENT TO ADJOURN THE PARK SPECIAL MEETING FOR THE PURPOSE OF
SOLICITING FURTHER SUPPORT FOR ADOPTION OF THE MERGER AGREEMENT.

       The Park board of directors is not currently aware of any matters other
than those referred to above which will come before the Park special meeting. If
any other matter should be presented at the Park special meeting for action, the
individuals named in the accompanying proxy card will vote the Park common
shares represented thereby in their own discretion.

       A Park shareholder may revoke a proxy at any time before it is actually
voted at the Park special meeting by delivering written notice of revocation to
the Secretary of Park, David C. Bowers, by submitting a later-dated proxy, or by
attending the Park special meeting and voting in person. ATTENDANCE AT THE PARK
SPECIAL MEETING WILL NOT, IN AND OF ITSELF, CONSTITUTE A REVOCATION OF A PROXY.

       Park and Security will share the cost of preparing, printing and mailing
proxy materials to Park shareholders. Proxies may be solicited personally or by
telephone, mail or telegraph. Officers or employees of Park may assist with
personal or telephone solicitation and will receive no additional compensation
for doing so. Park will also reimburse brokerage houses and other nominees for
their reasonable expenses in forwarding proxy materials to beneficial owners of
Park common shares.

                          THE SECURITY SPECIAL MEETING

       This joint proxy statement/prospectus is furnished to the shareholders of
Security in connection with the solicitation on behalf of the board of directors
of Security of proxies for use at the Security special meeting to be held at
[                      ], Ohio, on [     ], [     ], 2001 at [  ]:00 [_.M.],
local time, or any adjournment of the Security special meeting. This joint proxy
statement/prospectus and the accompanying form of proxy card were first mailed
to Security shareholders on or about [      ], 2001.

MATTERS TO BE CONSIDERED AT THE SECURITY SPECIAL MEETING

       At the Security special meeting, Security shareholders will be asked to
consider and vote upon the adoption of the merger agreement. Security
shareholders also will consider and vote upon any other business which properly
comes before the Security special meeting.

       The Security board of directors has unanimously approved the merger
agreement and recommends that the Security shareholders vote "FOR" adoption of
the merger agreement.

VOTING AT THE SECURITY SPECIAL MEETING; SECURITY RECORD DATE

       Only holders of record of Security common shares at the close of business
on [      ], 2001 will be entitled to notice of, and to vote at, the Security
special meeting. As of that date, there were [11,777,700] Security common shares
issued and outstanding. Each Security common share entitles the holder to one
vote on each matter to be submitted to the Security shareholders at the Security
special meeting. A majority of the issued and outstanding Security common shares
constitutes a quorum for the Security special meeting.

       Security common shares represented by signed proxy cards or voting
instructions that are returned to Security will be counted toward the quorum in
all matters even though they are marked as "abstain" or "against" or they are
not marked at all. Broker non-votes will also count toward the establishment of
a quorum. BECAUSE THE AFFIRMATIVE VOTE OF THE HOLDERS OF AT LEAST TWO-THIRDS OF
THE ISSUED AND OUTSTANDING SECURITY COMMON SHARES IS REQUIRED TO ADOPT THE
MERGER AGREEMENT, THE EFFECT OF AN ABSTENTION OR BROKER NON-VOTE IS THE SAME AS
A "NO" VOTE.

       If a Security shareholder properly signs and returns the accompanying
proxy card to Security prior to the Security special meeting and does not revoke
it, the proxy will be voted in accordance with the instructions contained on the
card. If a Security shareholder does not give any instructions, the individuals
designated as proxies


                                       18


<PAGE>   29


in the accompanying proxy card will vote "FOR" adoption of the merger agreement.
In that event, the Security shareholder will not have the right to dissent from
the merger and demand payment of the "fair cash value" of that shareholder's
Security common shares.

       THE PROXIES OF THE SECURITY BOARD OF DIRECTORS MAY NOT VOTE SECURITY
COMMON SHARES REPRESENTED BY A PROXY CARD WHICH HAVE BEEN VOTED "AGAINST"
ADOPTION OF THE MERGER AGREEMENT TO ADJOURN THE SECURITY SPECIAL MEETING FOR THE
PURPOSE OF SOLICITING FURTHER SUPPORT FOR ADOPTION OF THE MERGER AGREEMENT.

       The Security board of directors is not currently aware of any matters
other than those referred to above which will come before the Security special
meeting. If any other matter should be presented at the Security special meeting
for action, the individuals named in the accompanying proxy card will vote the
Security common shares represented thereby in their own discretion.

       A Security shareholder may revoke a proxy at any time before it is
actually voted at the Security special meeting by delivering written notice of
revocation to the Executive Vice President and Secretary of Security, J. William
Stapleton, by submitting a later-dated proxy, or by attending the Security
special meeting and voting in person. ATTENDANCE AT THE SECURITY SPECIAL MEETING
WILL NOT, IN AND OF ITSELF, CONSTITUTE A REVOCATION OF A PROXY.

       Park and Security will share the cost of preparing, printing and mailing
proxy materials to the Security shareholders. Proxies may be solicited
personally or by telephone, mail or telegraph. Officers or employees of Security
may assist with personal or telephone solicitation and will receive no
additional compensation for doing so. Security will also reimburse brokerage
houses and other nominees for their reasonable expenses in forwarding proxy
materials to beneficial owners of Security common shares.

                         PRINCIPAL SHAREHOLDERS OF PARK

       The following table provides information regarding the beneficial
ownership of Park common shares as of December 15, 2000, for each of the current
directors of Park, each of the executive officers of Park, all directors and
executive officers of Park as a group, and each person known by Park to
beneficially own more than 5% of the outstanding Park common shares. As of
December 15, 2000, none of the directors or executive officers of Park held
Security common shares.


                                       19


<PAGE>   30


                  Amount and Nature of Beneficial Ownership (1)


<TABLE>
<CAPTION>
                               Park Common Shares
                                  Which Can Be
                                  Acquired Upon                                                   Percent of Class (2)
Name of Beneficial                       Park            Exercise of Options                      --------------------
Owner or Number of                  Common Shares            Exercisable                       December 15,    Post-
of Persons in Group                 Presently Held         Within 60 Days         Total             2000       Merger (3)
-------------------                 --------------         --------------         -----             ----       ----------

<S>                                <C>                      <C>                <C>               <C>          <C>
The Park National Bank,
    Trust Department
50 North Third Street
Newark, OH  43055                  1,157,298 (4)                    0           1,157,298          10.7%        8.2%

John L. Warner
355 Bryn Du Drive
Granville, OH  43023                 803,123 (5)                    0             803,123           7.4%        5.7%
Maureen Buchwald                       1,717                    1,303               3,020           (6)         (6)
James J. Cullers                       8,519 (7)                  651               9,170           (6)         (6)
C. Daniel DeLawder (8)                83,603 (9)                6,499              90,102           (6)         (6)
D. C. Fanello                          1,619 (10)                   0               1,619           (6)         (6)
R. William Geyer                       5,032 (11)                   0               5,032           (6)         (6)
Philip H. Jordan, Jr., Ph.D.           3,862 (12)                   0               3,862           (6)         (6)
Howard E. LeFevre                     48,139 (13)(14)               0              48,139           (6)         (6)
Phillip T. Leitnaker                   2,705 (15)                   0               2,705           (6)         (6)
William T. McConnell (8)             193,350 (13)(16)               0             193,350           1.8%        1.4%
James A. McElroy                      35,224 (17)               1,303              36,527           (6)         (6)
John J. O'Neill                      142,152 (13)                   0             142,152           1.3%        1.0%
William A. Phillips                    8,947 (18)                   0               8,947           (6)         (6)
J. Gilbert Reese                     432,456 (13)(19)               0             432,456           4.0%        3.1%
Rick R. Taylor                         1,644                        0               1,644           (6)         (6)
David C. Bowers (8)                   28,940 (20)               4,700              33,640           (6)         (6)


All current executive
   officers and directors as
   a group (16 persons)            1,801,032 (21)              14,456           1,815,488          16.8%       12.8%
</TABLE>

------------------------

       (1)    Unless otherwise noted, the beneficial owner has sole voting and
investment power with respect to all of the Park common shares reflected in the
table. All fractional Park common shares have been rounded to the nearest whole
common share.

       (2)    The percent of class is based on 10,783,682 Park common shares
outstanding and entitled to vote on December 15, 2000, and the number of Park
common shares, if any, as to which the named individual has the right to acquire
beneficial ownership upon the exercise of options exercisable within 60 days of
that date.

       (3)    The post-merger percent of class is based on 10,783,682 Park
common shares outstanding on December 15, 2000, plus the issuance of 3,350,000
Park common shares in the merger. The officers and directors of Park disclaim
beneficial ownership of the 15,000 Security common shares held by Park.

       (4)    The Trust Department of Park National Bank, as the fiduciary of
various agency, trust and estate accounts, has sole voting and investment power
with respect to 1,147,848 of these Park common shares and shared voting and
investment power with respect to 9,450 of these Park common shares. The officers
and directors of Park National Bank and Park disclaim beneficial ownership of
the Park common shares beneficially owned by the Trust


                                       20


<PAGE>   31


Department of Park National Bank. The number shown does not include Park common
shares held by Park National Bank's Trust Department in various trust accounts,
as to which Park National Bank's Trust Department has no voting or investment
power.

       (5)    The number shown includes 358,386 Park common shares held by Mr.
Warner in a family trust for which Mr. Warner serves as trustee and exercises
sole voting and investment power; 9,450 Park common shares held in a family
trust for which he serves as co-trustee with Park National Bank's Trust
Department and exercises shared voting and investment power; and 6,022 Park
common shares held by the wife of Mr. Warner as to which she exercises sole
voting and investment power.

       (6)    Represents ownership of less than 1% of the outstanding Park
common shares.

       (7)    The number shown includes 609 Park common shares held by Mr.
Cullers' wife; 640 Park common shares held in a trust with respect to which Mr.
Cullers has sole voting and investment power; 4,142 Park common shares held in a
Keough plan maintained by Mr. Cullers' law firm with respect to which Mr.
Cullers has voting and investment power; 165 Park common shares held by Mr.
Cullers as custodian for his grandchildren; and 89 Park common shares held by
Mr. Cullers' wife as custodian for their grandchildren. The number shown does
not include 20,127 Park common shares held by Mr. Cullers as trustee of a trust
as to which the grantor has retained sole voting and investment power.

       (8)    Executive officer of Park.

       (9)    The number shown includes 34,965 Park common shares held by the
wife of Mr. DeLawder as to which she exercises sole voting and investment power;
1,355 Park common shares held by Mr. DeLawder's daughter and 1,355 Park common
shares held by Mr. DeLawder's son as to which Mr. DeLawder exercises shared
voting and investment power; and 6,829 Park common shares held for the account
of Mr. DeLawder in the Park National Corporation Employees Voluntary Salary
Deferral Plan and Trust (the "Park 401(k) Plan").

       (10)   The number shown includes 1,199 Park common shares held in a trust
as to which Mr. Fanello has sole voting and investment power; but does not
include 420 Park common shares held in a grantor trust established for the
benefit of the wife of Mr. Fanello, with respect to which Park common shares Mr.
Fanello has no voting or investment power.

       (11)   The number shown includes 613 Park common shares held by the wife
of Mr. Geyer as to which she exercises sole voting and investment power; and
2,835 Park common shares held in Mr. Geyer's account in a Keough plan.

       (12)   The number shown includes 3,863 Park common shares held in a trust
with respect to which Mr. Jordan has sole voting and investment power.

       (13)   The number shown does not include 31,213 Park common shares owned
by the Newark Campus Development Fund, an Ohio not for profit corporation, of
which the following directors of Park serve as officers and/or trustees: Messrs.
LeFevre, McConnell, O'Neill and Reese. None of these individuals has the power
to vote these Park common shares without the consent of a majority of the Newark
Campus Development Fund's board of trustees and, therefore, each disclaims
beneficial ownership of the Park common shares.

       (14)   The number shown includes 48,139 Park common shares held in an
inter vivos trust created by Mr. LeFevre for which Park National Bank's Trust
Department serves as trustee and Mr. LeFevre exercises sole voting and
investment power.

       (15)   The number shown includes 980 Park common shares held jointly by
Mr. Leitnaker and his wife as to which they share voting and investment power;
and 525 Park common shares held by the wife of Mr. Leitnaker as to which she
exercises sole voting or investment power.


                                       21


<PAGE>   32


       (16)   The number shown includes 70,444 Park common shares held by the
wife of Mr. McConnell as to which she exercises sole voting and investment
power; 16,170 Park common shares held in an inter vivos irrevocable trust
established by Mr. McConnell with respect to which Park National Bank's Trust
Department serves as trustee; and 3,906 Park common shares held for the account
of Mr. McConnell in the Park 401(k) plan.

       (17)   The number shown includes 20,127 Park common shares held in a
trust as to which Mr. McElroy exercises sole voting and investment power; 12,677
Park common shares owned by AMG Industries, Inc., a corporation controlled by
Mr. McElroy; and 670 Park common shares held by Mr. McElroy's wife as to which
she exercises sole voting and investment power.

       (18)   The number shown includes 1,090 Park common shares held for the
account of Mr. Phillips in the Park National 401(k) plan and 3,675 Park common
shares held by Mr. Phillips' wife as to which she exercises sole voting and
investment power.

       (19)   The number shown includes 53,676 Park common shares held by the
wife of Mr. Reese as to which she exercises sole voting and investment power.

       (20)   The number shown includes 4,539 Park common shares held for the
account of Mr. Bowers in the Park 401(k) plan and 2,921 Park common shares held
by Mr. Bowers' wife as to which she exercises sole voting and investment power.

       (21)   See Notes (5), (7) and (9) through (20) above.

                       PRINCIPAL SHAREHOLDERS OF SECURITY

       The following table furnishes information regarding the beneficial
ownership of Security common shares as of December 15, 2000, for each of the
current directors of Security, each of the executive officers of Security, all
directors and executive officers of Security as a group, and each person known
by Security to beneficially own more than 5% of the outstanding Security common
shares. As of December 15, 2000, none of the directors or executive officers of
Security held Park common shares.


                                       22


<PAGE>   33


                  Amount and Nature of Beneficial Ownership(1)

<TABLE>
<CAPTION>
                                                    Security
                                                  Common Shares
                                                  Which Can Be
                                                  Acquired Upon
                                                   Exercise of                    Percentage
                                                  In-the-Money                     Ownership   Park Common   Post-Merger
    Name of Beneficial            Security           Options                          of       Shares to be   Percentage
      Owner or Number          Common Shares       Exercisable                     Security    Received in    Ownership
    of Persons in Group        Presently Held    Within 60 Days       Total          (2)        Merger(3)    of Park (4)
    -------------------        --------------    --------------       -----          ----       ---------    -----------
<S>                            <C>               <C>                <C>            <C>          <C>           <C>
Fleet National Bank,              681,168                0            681,168         5.8%        193,724         1.4%
  Co-Trustee(5)
159 E. Main St.
Rochester, NY 14604
         and
Robert E. Harley,
  Co-Trustee(5)
1 South Limestone St.
Springfield, OH 45501
Security National Bank,         1,968,973                0          1,968,973        16.7%        559,975         4.0%
  Trust Department
40 South Limestone St.
Springfield, OH 45502
Vincent J. Denama                  56,112 (6)            0             56,112          *           15,958          **
Harry O. Egger                    134,146 (7)       14,000            148,146         1.3%         38,151          **
Larry D. Ewald                     43,036 (8)            0             43,036          *           12,239          **
Scott A. Gabriel                   11,153 (9)            0             11,153          *            3,171          **
Larry E. Kaffenbarger               4,845                0              4,845          *            1,377          **
Richard E. Kramer                  34,659 (10)           0             34,659          *            9,857          **
Dr. Karen E. Nagle                    655                0                655          *              186          **
Thomas J. Veskauf                   6,170 (11)           0              6,170          *            1,754          **
Chester L. Walthall                 4,096 (12)           0              4,096          *            1,164          **
Robert A. Warren                    3,490                0              3,490          *              992          **
James R. Wilson                    42,874 (13)           0             42,874          *           12,193          **
William C. Fralick                 24,894 (14)      14,000             38,894          *            7,079          **
J. William Stapleton               37,443 (15)       8,400             45,843          *           10,648          **

All current directors and
executive officers as a
group (13 persons)                403,573           36,400            439,973         3.7%        114,769         0.8%
</TABLE>

---------------

       *      Represents ownership of less than 1% of the outstanding common
shares of Security.

       **     Represents ownership of less than 1% of the outstanding common
shares of Park following the merger.

       (1)    Unless otherwise noted, the beneficial owner has sole voting and
investment power with respect to all of the Security common shares reflected in
the table.


                                       23


<PAGE>   34


       (2)    The percentage of Security common shares owned is based on
11,777,700 Security common shares outstanding and entitled to vote on December
15, 2000, and the number of Security common shares, if any, as to which the
named individual has the right to acquire beneficial ownership upon the exercise
of options exercisable within 60 days of that date.

       (3)    The number of Park common shares to be received in the merger is
based on the number of Security common shares owned as of December 15, 2000
(excluding the number of Security common shares, if any, as to which the named
individual has the right to acquire beneficial ownership upon the exercise of
options exercisable within 60 days of that date) multiplied by the exchange
ratio of .2844.

       (4)    The post-merger percentage of Park common shares owned is based on
10,783,682 Park common shares outstanding on December 15, 2000 plus the issuance
of 3,350,00 Park common shares in the merger, and the number of Park common
shares which the named individual will have the right to acquire beneficial
ownership upon the exercise of converted options.

       (5)    The number shown represents Security common shares held by Fleet
National Bank and Security National Bank as co-trustees of the Jane P. B.
Hollenbeck Trust.

       (6)    The number shown includes 2,100 Security common shares held by the
wife of Mr. Demana.

       (7)    The number shown includes 60,359 Security common shares held by
the wife of Mr. Egger.

       (8)    The number shown includes 15,352 Security common shares held by
the wife of Mr. Ewald and 8,000 Security common shares held in a trust as to
which Mr. Ewald, as co-trustee, shares voting and investment power.

       (9)    The number shown includes 185 Security common shares held by the
wife of Mr. Gabriel.

       (10)   The number shown includes 2,379 Security common shares held by the
wife of Mr. Kramer and 25,216 Security common shares held in a trust as to which
Mr. Kramer shares voting and investment power.

       (11)   The number shown includes 1,790 Security common shares held by the
wife of Mr. Veskauf and 100 Security common shares held in a trust by Mr.
Veskauf's wife.

       (12)   The number shown includes 3,032 Security common shares held by the
wife of Mr. Walthall.

       (13)   The number shown includes 13,092 Security common shares held by
the wife of Mr. Wilson and 14,300 Security common shares held by Mr. Wilson's
children.

       (14)   The number shown includes 8,000 Security common shares held by the
wife of Mr. Fralick.

       (15)   The number shown includes 13,261 Security common shares held by
the wife of Mr. Stapleton.

                                   THE MERGER

       This section of the joint proxy statement/prospectus contains a summary
of the material terms of the merger. The following description summarizes all of
the material terms of the merger; however, we do not address every provision of
the merger agreement and qualify our description by reference to the merger
agreement. A copy of the merger agreement is attached to this document as
Appendix A. Park and Security urge you to read the merger agreement in its
entirety.

       Under the terms of the merger agreement, at the effective time of the
merger, Security will merge into Park and the separate existence of Security
will end. At that time, each issued and outstanding Security common share, other
than those as to which dissenters' rights are perfected, will be converted into
approximately .2844 Park common shares. All Security common shares owned by
Security as treasury shares will be canceled and retired and


                                       24


<PAGE>   35


no Park common shares or other consideration will be delivered in exchange for
those Security common shares. For more information, see "The Merger - Effect on
Outstanding Park Common Shares and Exchange of Security Common Shares - Exchange
of Security Common Shares" on page [ ]. As discussed further below, the
consideration to be received by the Security shareholders in the merger was
determined by arm's-length negotiations between the management of Park and
Security.

       Park has provided all information contained in this joint proxy
statement/prospectus relating to Park and Security has provided all information
relating to Security . The party providing the information is responsible for
the accuracy of that information.

BACKGROUND

       The terms and conditions of the merger agreement were determined through
arm's-length negotiations between the management and boards of directors of
Security and Park. The following is a brief summary of those negotiations.

       William T. McConnell, Chairman of the Board of Park, and C. Daniel
DeLawder, President and Chief Executive Officer of Park, have been acquainted
for a number of years with Harry O. Egger, Chairman, President and Chief
Executive Officer of Security. The three have been active in bank trade
association work, and have shared "best practices" of their respective
organizations on several occasions.

       Messrs. Egger and McConnell have had a number of conversations and visits
spanning nearly twenty years, during which time they developed considerable
knowledge of each other's financial institutions and operating methods. There
are several examples where these visits led to changes in a particular procedure
or product resulting in improved performance. Both Security National Bank and
Park National Bank have consistently been high performing banks, and the sharing
of various types of information has contributed to their success. In short, the
two banks perform very much alike.

       During several visits, Messrs. Egger and McConnell had conversations
concerning the possible advantages of a business combination of the two bank
holding companies. Such conversations preceded a meeting on October 26, 1999, in
the Columbus office of Park National Bank among Messrs. Egger, McConnell and
DeLawder.

       At that time, it was clear substantive change was occurring in the
banking industry. Among several changes discussed were increased reliance on
expensive technology, the rapid consolidation of banks through mergers as well
as the further de-regulation of the banking industry. These issues were offered
as strong evidence by Messrs. McConnell and DeLawder that a combination of
Security and Park could be advantageous to the organizations' respective
communities, shareholders and employees.

       Messrs. McConnell and DeLawder also shared numerous reasons for the
historical success of Park, especially during the past fifteen years. Park has
grown through affiliation with other highly respected community banks to create
an organization of a family of banks having a presence in fifteen different
counties in Ohio, operating 60 banking offices through six different banks. It
was emphasized these banks continue to operate with their pre-merger identity,
boards of directors and substantially the same staff. This continuing form of
organization has contributed to each bank's recognition as a leader in its
market.

       Through the combination of these banks under one form of ownership,
economies of scale have been realized that, in addition to the community bank
focus, has enabled Park to remain a highly successful organization. The
additional size through the combination of the banks has been a factor allowing
significant capital expenditures to be made concurrent with product and service
development. It is strongly believed that Park, and each of Park's subsidiary
banks, has been able to be very responsive to community financial needs, and to
itself be more profitable as a result.

       Messrs. McConnell and DeLawder suggested the combination of Security and
Park, while not guaranteed, would be advantageous to their respective
constituencies. Importantly, a merger would provide a more sizable base from
which they could effectively compete to the benefit of the resulting
corporation.


                                       25


<PAGE>   36


       While a value for Security's shareholders was not addressed specifically,
it was suggested that Park's analysis would include the current and prospective
earnings contributions of the respective corporations. The analysis should allow
a conclusion to be drawn that would prove to be mutually acceptable to all
parties. Mr. Egger acknowledged the discussion points had considerable merit,
and he intended to give considerable thought to the proposed combination.

       A few weeks later, on December 17, 1999, Mr. DeLawder called Mr. Egger to
inform Mr. Egger that Park had signed a definitive agreement to acquire SNB
Corp., a one bank holding company operating in Darke and Mercer counties under
the name of Second National Bank. Both counties are immediately adjacent to
counties in which Security has banking offices.

       The agreement with SNB Corp. was signed one week after Park had signed a
similar agreement to acquire U.B. Bancshares, Inc., a one bank holding company
operating in Crawford and Marion counties under the name of United Bank, N.A.
Mr. DeLawder stated these two additional banks, when the mergers were completed
early in 2000, would bring the total banks owned by Park to eight, operating in
20 counties through 78 different offices. Mr. DeLawder attempted to make clear
that the combination of Security with Park was not only still possible, but
highly desirable. Following the closing of the SNB Corp. and U.B. Bancshares
mergers, the three banks owned by Security, and operating in six counties now
all adjacent to counties in which Park subsidiary banks have a physical
presence, would be a natural geographic fit within the Park organization. Mr.
DeLawder encouraged Mr. Egger to give further thought to the proposition, to
which Mr. Egger agreed.

       Mr. DeLawder next called Mr. Egger on February 15, 2000, to see if Mr.
Egger had additional questions or perhaps had come to any conclusion. Mr. Egger
responded that he was still giving the possible combination serious
consideration, but was not yet prepared to talk further. The two agreed to
remain in touch over the next several months.

       Mr. DeLawder again called Mr. Egger on May 1, 2000, to let Mr. Egger know
the closings for the U.B. Bancshares and SNB Corp. mergers had occurred. Mr.
DeLawder also reiterated Park's strong desire to continue discussions of a
possible combination of Security and Park. Mr. Egger suggested they talk again
sometime during the later part of June, and Mr. DeLawder agreed to call at that
time.

       On June 22, 2000, Messrs. Egger and DeLawder had another telephone
conversation, and agreed to meet on July 12, 2000. Mr. Egger invited Mr.
DeLawder to Security National Bank in Springfield, to continue discussions.
During the visit, Messrs. Egger and DeLawder discussed, at considerable length,
several issues. Among them, the resulting structure of the three financial
institutions owned by Security, the staff and boards of the respective financial
institutions and those financial institutions' continuing ability to respond to
community needs received the greatest attention. Mr. DeLawder responded by
providing several examples of how the subsidiary banks of Park operated, with an
emphasis on the continuing identity of each bank and its considerable autonomy.
At the conclusion of the meeting, Mr. Egger suggested it might be beneficial for
he and Mr. McConnell to meet again to discuss these and other issues.

       At a meeting on July 19, 2000, Messrs. Egger and McConnell discussed
corporate governance issues, and specifically, how Security's interest would be
represented in a possible combination of the corporations. Mr. McConnell stated
Park's management would welcome the input of Mr. Egger in the future, and
suggested Mr. Egger would be recommended to join the board of Park, and
additionally, be elected vice chairman of the board. Both steps would allow
Park's interest in the western part of Ohio to be actively and substantively
represented. Mr. Egger's considerable experience would also be an asset to the
organization in all other matters as well.

       Mr. McConnell addressed the earnings valuation approach favored by Park.
They revisited the discussion of October 26, 1999 dealing with the pricing
discipline and valuation model embraced by Park. Mr. McConnell emphasized the
equitable nature of such a combination. Shareholders of both corporations would
have ownership in the resulting corporation based on their respective level of
earnings contributed.

       Mr. McConnell suggested that while Park has a very good sense of earnings
for Park, it would be beneficial for Mr. Egger to share further financial
information about Security with Park in order for additional projections by Park
to be possible. They agreed to continue discussions, and to share respective net
income information.


                                       26


<PAGE>   37


       During a meeting on August 16, 2000, Messrs. Egger and DeLawder discussed
information intended to allow both parties to gain a better understanding of the
net income potential of each, and as well, to learn of any special conditions
existing with asset quality, legal issues or other factors that could influence
a valuation of either organization. In the absence of information that would
negatively influence valuation, both agreed to proceed. Mr. DeLawder requested
another meeting, and the two agreed to meet on September 1, 2000 in Columbus.

       During the September 1, 2000 meeting, Mr. DeLawder shared the earnings
valuation procedure that resulted in Park's offering 3,300,000 common shares as
the total consideration in exchange for the outstanding Security common shares,
including common shares subject to outstanding options. Mr. Egger acknowledged
the offer, subject in both cases to board approval, and invited Mr. DeLawder to
Springfield to further discuss the proposal.

       During a September 13, 2000 meeting, Mr. Egger provided additional
information as Security's basis for requesting that the aggregate consideration
the Security shareholders would receive be increased by several thousand Park
common shares. Mr. Egger also suggested he might not want to continue employment
if the proposed merger occurred. Mr. DeLawder expressed disappointment in Mr.
Egger's personal position, and stated the consideration offered by Park assumed
the continued employment of Mr. Egger as the Chief Executive Officer of Security
National Bank with continuing responsibility for the other two financial
institutions owned by Security. They both agreed to give additional thought to
the points raised during the meeting, and agreed they should meet again on
September 27, 2000.

       During a September 27, 2000 meeting, Mr. DeLawder stated that without Mr.
Egger, the offer for Security would be considerably less. Further, Park's
management concluded the offer of 3,300,000 Park common shares was appropriate,
if Mr. Egger agreed to continue employment. Mr. Egger agreed to consider
continuing employment, but was reluctant to accept Park's conclusion not to
offer additional common shares. Mr. Egger suggested that several of the senior
staff of Security meet with several senior staff of Park to further discuss
earnings opportunities and clarify any questions Park may have.

       Subsequently, Messrs. William C. Fralick, J. William Stapleton, James R.
Wilson and Scott A. Gabriel, all representing the three financial institutions
owned by Security, met with Messrs. DeLawder, David C. Bowers, John W. Kozak and
David L. Trautman, who represented banks owned by Park. The meeting occurred on
October 5, 2000 in Columbus, Ohio. During the meeting, schedules were exchanged
that contained considerable detail requested by both corporations in order to
become better informed of the other. Discussions at length occurred that allowed
the representatives from Security to learn more thoroughly the operating style
of Park and the differences in subsidiary bank approaches in the several markets
served by Park's subsidiary banks.

       Messrs. Egger and DeLawder next talked by telephone on October 12, 2000.
Mr. Egger agreed to consider full-time employment. They talked further about
consideration issues, and agreed a face-to-face meeting would be more
appropriate. Mr. DeLawder next visited Mr. Egger at his office in Springfield on
October 20, 2000. During this meeting, Mr. Egger reviewed in further detail his
reasoning for an increase in the valuation of Security. Additionally, Mr. Egger
had conferred with selected senior staff of Security, and they confirmed his
conclusions on valuation.

       Before proceeding further, Messrs. Egger and DeLawder concluded it would
be appropriate to enter into a more formal stage of discussion, and each agreed
to seek approval from his board of directors to enter into a confidentiality
agreement. Appropriate approval was subsequently received, and a confidentiality
agreement was signed by Security and Park on October 27, 2000.

       Messrs. Egger and DeLawder met again on November 1, 2000 in Columbus,
Ohio. Mr. DeLawder stated that Park's management had recommended to Park's
executive committee, on October 27, 2000, that the total consideration for the
merger with Security be increased to 3,350,000 Park common shares. The
consideration was to accommodate the Security common shares subject to
outstanding options, and represented an increase from Park's original offer as a
result of a better understanding of Security's future prospects. Mr. Egger then
responded he would make the proposal known to the board of Security, and he
planned to schedule a meeting for November 16, 2000. He also stated the meeting
would include a representative from Austin Associates, Inc., who Security


                                       27


<PAGE>   38


would engage to render a fairness opinion on the proposed transaction.
Additionally, Austin Associates would be asked to discuss with Security's board
of directors the alternatives that may be available to the Security board.

       Following this meeting, Mr. Egger called Mr. DeLawder on November 17,
2000, to inform him that the Security board had agreed in concept to consider
the proposal, but Mr. Egger was of the opinion that the number of Park common
shares to be exchanged should be increased. Mr. DeLawder noted that a meeting of
Park's executive committee was scheduled for later that same day. Management
planned to make a recommendation to the executive committee regarding Security,
and the executive committee would in turn make a recommendation to the Park
board of directors on Monday, November 20, 2000, if appropriate.

       Mr. DeLawder shared with Mr. Egger that Messrs. McConnell and DeLawder
were now prepared to recommend that the merger consideration be 3,350,000 Park
common shares. Further, they planned to recommend that Park assume the
obligations related to the common shares issuable upon exercise of outstanding
Security options. This assumption would result in an additional approximately
50,000 Park common shares being issuable in connection with the transaction.

       Subsequently, Park's executive committee and Park's board of directors
met on November 20, 2000 to ratify the recommendations outlined above.
Security's board also met on Monday, November 20, 2000, and approved the terms
as outlined.

REASONS FOR THE MERGER

       The decision of the Park board of directors and the Security board of
directors to approve the merger agreement and to recommend that their respective
shareholders adopt the merger agreement is the result of each board of
directors' individual assessment of the opportunities to enhance shareholder
value as a result of the merger.

       The board of directors of Security believes that the merger with Park is
fair and in the best interest of Security and its shareholders and recommends
that the Security shareholders vote "FOR" adoption of the merger agreement. The
Security board of directors considered all of the following factors in approving
the merger agreement and believes that each of the factors represents an
important reason why it is recommending that its shareholders vote in favor of
adopting the merger agreement:

       -      the opinion of Austin Associates that the exchange ratio provided
              for in the merger agreement was fair to Security shareholders from
              a financial point of view;

       -      the overall financial terms of the merger;

       -      current long-term industry development and trends;

       -      competitive factors;

       -      the business and financial condition and earnings prospects of
              Park;

       -      the competence, experience and integrity of Park's management;

       -      the adequacy of the consideration to be received by Security's
              shareholders in the merger;

       -      the historical trading prices of the Security common shares; and

       -      future prospects for Security.


                                       28


<PAGE>   39


       In negotiating the terms of the merger, management of Park considered a
number of factors with a view to maximizing shareholder value in the
intermediate and long term, including:

       -      the earnings potential of the combined business;

       -      the strengthened capital base of the combined business;

       -      the potential realization of economies of scale;

       -      the growth prospects within the existing market area of Security's
              subsidiaries; and

       -      expansion of the community banking model successfully employed by
              Park.

       Park has a proven history of successfully joining with other community
banks to offer products and services of such high value that the banks are
viewed as unique within their respective markets. Park and Security believe that
Security's three subsidiary financial institutions will have the benefit of
replicating Park's subsidiary bank strategies, practices and procedures that
have allowed Park to gain competitive advantages within the respective markets
served by the subsidiary financial institutions.

       Park's management believes the markets served by Security have similar
potential for product and service delivery. Security's market areas have many
parallels characteristic to those markets currently served by Park. It is
expected that Security's markets will be receptive to the Park approach to
banking and accordingly, will provide levels of profitability comparable to
those of the other banking subsidiaries of Park.

       Additionally, the former subsidiaries of Security will add value to the
existing subsidiaries of Park by sharing unique approaches that have been
successful for Security. Park has benefited from each new community bank that
has joined the Park organization over the years, and it is expected the addition
of the former subsidiaries of Security will be beneficial for existing Park
subsidiary banks in a similar fashion.

       Security's subsidiaries operate within attractive geographic areas of
Ohio, served by interstate highways 70 and 75. These markets have enjoyed higher
growth than some of the current markets served by Park's subsidiary banks, and
are desirable market area extensions for Park. Further, with the three Security
subsidiaries situated near the expanding Columbus, Ohio and Dayton, Ohio
metropolitan areas, Park and Security believe the markets will enjoy
above-average growth over the next several years.

       The combined capital base of the corporations should allow for
significant and necessary investment in evolving technology. In order to remain
competitive with regional and super regional banking companies, Park and
Security believe it is critical to have the capacity to invest in computer
hardware and software, physical facilities and other delivery methods in order
to attract and retain customers. Such investments, made within the context of a
larger organization, would be shared by a larger base of customers, and the
investments on a relative basis would be more affordable. Economies of scale are
expected to realized, and shareholder value further enhanced by such
combination.

       Park's primary financial goal is to achieve a superior long-term return
on shareholders' equity which the Park board of directors believes may be
achieved through the merger. The tables below compare (1) the return on average
assets for Park, all U.S. bank holding companies with $3 billion to $10 billion
in consolidated assets and Security, and (2) the return on average equity for
Park, all U.S. bank holding companies with $3 billion to $10 billion in
consolidated assets and Security.


                                       29


<PAGE>   40


<TABLE>
<CAPTION>
                                                           RETURN ON AVERAGE ASSETS
                                                            Year ended December 31,
                                        ----------------------------------------------------------------
                                               1997               1998                   1999
                                               ----               ----                   ----

<S>                                           <C>                 <C>                   <C>
Park                                          1.65%               1.69%                 1.56%
Peer U.S. bank holding companies              1.26%               1.19%                 1.17%
Security                                      1.75%               1.85%                 1.78%
</TABLE>

<TABLE>
<CAPTION>
                                                           RETURN ON AVERAGE EQUITY
                                                            Year ended December 31,
                                        ----------------------------------------------------------------
                                               1997               1998                   1999
                                               ----               ----                   ----

<S>                                           <C>                <C>                    <C>
Park                                          17.18%             17.12%                 16.28%
Peer U.S. bank holding companies              14.13%             13.40%                 13.75%
Security                                      13.92%             13.69%                 14.18%
</TABLE>


OPINION OF AUSTIN ASSOCIATES, INC.

       Security retained Austin Associates to provide financial advisory
services in connection with the merger. Security selected Austin Associates as
its financial advisor on the basis of Austin Associates' past relationship with
Security, and Austin Associates' experience and expertise in representing
community banks in similar transactions. Austin Associates is an investment
banking and consulting firm specializing in community bank mergers and
acquisitions.

       In conjunction with the meeting of Security's board of directors held on
November 20, 2000 to consider the merger and approve the merger agreement,
Austin Associates delivered its opinion that the terms provided for in the
merger agreement are fair, from a financial point of view, to the shareholders
of Security.

       Shareholders should consider the following when reading the discussion of
Austin Associates' opinion:

       -      The summary of Austin Associates' opinion included in this joint
              proxy statement/prospectus is qualified in its entirety by
              reference to the full text of the opinion that is attached as
              Appendix B to this document. You should read the opinion in its
              entirety for a full discussion of the procedures followed,
              assumptions made, matters considered and qualifications and
              limitations of the review undertaken by Austin Associates in
              connection with its opinion.

       -      Austin Associates expresses no opinion as to the price at which
              Park common shares would actually be trading at any time.

       -      Austin Associates' opinion does not address the relative merits of
              the merger and the other business strategies considered by
              Security's board of directors, nor does it address the decision of
              Security's board of directors to proceed with the merger.

       -      Austin Associates' opinion to the Security board of directors
              rendered in connection with the merger does not constitute a
              recommendation to any Security shareholder as to how he or she
              should vote at the Security special meeting.

       -      No limitations were imposed by the Security board of directors or
              its management upon Austin Associates with respect to the
              investigations made or the procedures followed by Austin
              Associates in rendering its opinion.

       The preparation of a financial fairness opinion involves various
determinations as to the most appropriate methods of financial analysis and the
application of those methods to the particular circumstances. It is, therefore,
not readily susceptible to partial analysis or summary description. In
connection with rendering its opinion, Austin


                                       30


<PAGE>   41


Associates performed a variety of financial analyses. Austin Associates believes
that its analyses and the facts considered in its analyses, without considering
all other factors and analyses, could create an incomplete or inaccurate view of
the analyses and the process underlying the rendering of Austin Associates'
opinion.

       In performing its analyses, Austin Associates made numerous assumptions
with respect to industry performance, business and economic conditions, and
other matters, many of which are beyond the control of Park and Security and may
not be realized. Any estimates contained in Austin Associates' analyses are not
necessarily predictive of future results or values, which may be significantly
more or less favorable than the estimates. Estimates of values of companies do
not purport to be appraisals or necessarily reflect the prices at which the
companies or their securities may actually be sold. Except as described below,
none of the analyses performed by Austin Associates was assigned a greater
significance by Austin Associates than any other. The relative importance or
weight given to these analyses by Austin Associates is not effected by the order
of the analyses or the corresponding results. The summaries of financial
analyses include information presented in tabular format. The tables should be
read together with the text of those summaries.

       Austin Associates has relied, without independent verification, upon the
accuracy and completeness of the information it reviewed for the purpose of
rendering its opinion. Austin Associates did not undertake any independent
evaluation or appraisal of the assets and liabilities of Park or Security, nor
was it furnished with any appraisals. Austin Associates has not reviewed any
individual credit files of Park or Security and has assumed that Park's and
Security's allowances are, in the aggregate, adequate to cover losses. Austin
Associates' opinion is based on economic, market and other conditions existing
on the date of its opinion, and on information as of various earlier dates made
available to it which may not necessarily be indicative of current market
conditions.

       In rendering its opinion, Austin Associates made the following
assumptions:

       -      the merger will be accounted for as a pooling-of-interest in
              accordance with generally accepted accounting principles;

       -      all material governmental, regulatory and other consents and
              approvals necessary for the consummation of the merger will be
              obtained without any adverse effect on Security, Park or the
              anticipated benefits of the merger;

       -      Security had provided all of the information prepared by Security
              or its other representatives that might be material to Austin
              Associates in its review; and

       -      the financial projections Austin Associates reviewed were
              reasonably prepared on a basis reflecting the best currently
              available estimates and judgment of the management of Security as
              to the future operating and financial performance of Security.

       In connection with its opinion, Austin Associates reviewed:

       -      the merger agreement;

       -      audited financial statements of Park for the five years ended
              December 31, 1999 and unaudited financial statement summaries as
              of September 30, 2000;

       -      audited financial statements of Security for the five years ended
              December 31, 1999 and unaudited financial statement summaries as
              of September 30, 2000; and

       -      publicly available financial and operating information with
              respect to the business, operations and prospects of Park and
              Security.


                                       31


<PAGE>   42


       In addition, Austin Associates:

       -      reviewed the historical market prices and trading activity for the
              common shares of Park and Security, and compared the market
              activity of Park's common shares with that of certain publicly
              traded companies which it deemed to be relevant;

       -      compared the results of operations of Park with those of certain
              financial institutions which it deemed to be relevant;

       -      compared the financial terms of the merger with the financial
              terms, to the extent publicly available, of other recent business
              combinations of financial institutions;

       -      analyzed the pro forma equivalent financial impact of the merger
              to Security per share data; and

       -      conducted such other studies, analyses, inquiries and examinations
              as Austin Associates deemed appropriate.

       THE FOLLOWING IS A SUMMARY OF ALL MATERIAL ANALYSES PERFORMED BY AUSTIN
ASSOCIATES IN CONNECTION WITH ITS OPINION PROVIDED TO THE SECURITY BOARD OF
DIRECTORS AS OF NOVEMBER 20, 2000. THE SUMMARY DOES NOT PURPORT TO BE A COMPLETE
DESCRIPTION OF THE ANALYSES PERFORMED BY AUSTIN ASSOCIATES.

SUMMARY OF FINANCIAL TERMS OF MERGER

       Austin Associates reviewed the financial terms of the merger, including
the form of consideration, the number of Park common shares to be issued, and
the resulting value per share to be received by Security shareholders. Under the
terms of the merger agreement, Park will issue 3,350,000 common shares in
exchange for all the outstanding common shares of Security. Security's board of
directors may terminate the merger if the average closing sale price of a Park
common share, for the 20 trading day period immediately preceding the tenth day
prior to the effective time of the merger, is less than $77.50 and if the ratio
of the price decline for Park common shares exceeds the ratio of price decline
for shares of the common stock of a specific group of bank holding companies.
The merger consideration was determined through arm's-length negotiations
between the management of Park and Security.

       Based on 11,777,700 Security common shares outstanding as of the date of
the merger agreement, the exchange ratio would equal .2844. The .2844 exchange
ratio was calculated using the following steps. The consideration for all of
Security's outstanding common shares is 3,350,000 Park common shares. The
3,350,000 Park common shares issued in the transaction was divided by
11,777,700, the number of Security common shares outstanding as of the signing
of the merger agreement, to arrive at an exchange ratio of .2844. To determine
the per share value to Security shareholders, the exchange ratio is multiplied
by closing sale price of a Park common share on November 20, 2000. Based on
Park's closing share price on November 20, 2000 of $91.375, the value per share
to Security common shareholders is $25.99 ($91.375 multiplied by .2844). The
aggregate value of consideration to Security common shareholders equals the
total number of outstanding shares multiplied by the per share price. The
aggregate value, as of November 20, 2000, equaled $306.1 million ($25.99
multiplied by 11,777,700).

       In addition to the issuance of Park common shares, Park agreed to assume
and convert all outstanding options to purchase an aggregate of 174,999 Security
common shares into options to purchase Park common shares. The Security options
are exercisable at prices ranging from $7.63 to $46.00 per share. Based on the
$25.99 per share value to Security shareholders, the in-the-money value of the
options measures approximately $758,000. Based on the consideration payable for
the common shares and options of Security, the aggregate value of the
transaction is approximately $306.9 million.


                                       32


<PAGE>   43


INDUSTRY COMPARATIVE ANALYSIS

       In connection with rendering its opinion, Austin Associates compared
selected results of Park's operating performance to those of 11 Midwest-based
banking organizations having assets of between $2 billion and $5 billion,
including:

       -      Republic Bancorp, Inc., Owosso, Michigan
       -      AMCORE Financial Inc., Rockford, Illinois
       -      First Financial Bancorp., Hamilton, Ohio
       -      1st Source Corp., South Bend, Indiana
       -      Area Bancshares Corp., Owensboro, Kentucky
       -      Integra Bank Corp., Evansville, Indiana
       -      Gold Banc Corp., Leawood, Kansas
       -      Corus Bankshares Inc., Chicago, Illinois
       -      Intrust Financial Corp., Wichita, Kansas
       -      Community Trust Bancorp, Pikeville, Kentucky
       -      Irwin Financial Corp., Columbus, Indiana

       Austin Associates considered this group of financial institutions
comparable to Park on the basis of asset size and geographic location. Austin
Associates noted the following selected financial measures for the Midwest-based
banks as compared to Park for the period 1995 to September 30, 2000:

<TABLE>
<CAPTION>
                                                                                       MEDIAN FOR MIDWEST
                                                        PARK(1)                            PEER GROUP
                                                        ----                               ----------
                                             YTD 2000        95-99 Average        YTD 2000        95-99 Average
                                             --------        -------------        --------        -------------

<S>                                          <C>             <C>                  <C>             <C>
Core Return on Average Assets                   1.83%            1.71%              1.08%             1.23%
Core Return on Average Equity                  19.93%           18.23%             15.36%            13.84%
Asset Growth Rate                              29.20%           14.98%              9.27%            11.78%
Core E.P.S. Growth Rate(2)                      7.14%           14.57%             12.14%            14.77%
Leverage Ratio                                  9.36%            8.96%              8.40%             8.64%
Nonperforming Assets/Assets                     0.25%            0.28%              0.64%             0.58%
Net Loan Charge-Offs                            0.16%            0.20%              0.26%             0.32%
</TABLE>

------------------

(1) Park historical financial performance from 1995-1999 as reported through
November 20, 2000
(2) Core E.P.S. = Earnings per share excluding nonrecurring income and expenses

       Based on return on average assets and return on average equity, this
comparison indicated that Park has an above average level of overall
profitability. Park's historical growth rate in assets has exceeded the Midwest
peer group with core earnings growth approximating the peer's 1995-1999 average.
Park's level of capital as measured by the leverage ratio is above the Midwest
peer median. Park's asset quality measures compare very favorably to the Midwest
peer group.

       Austin Associates also reviewed share trading information as of November
20, 2000. The following represents a summary of this review.

<TABLE>
<CAPTION>
                                                                                         MEDIAN FOR MIDWEST
                                                                          PARK               PEER GROUP
                                                                          ----               ----------

<S>                                                                   <C>                   <C>
   Market Price to Core E.P.S.                                           17.8 x                10.7 x
   Market Price to Tangible Book Value                                    337%                  157%
   Average Daily Trading Volume in Shares                                3,431                 22,261
   Average Daily Value of Market Trades                                 $318,000              $439,000
   Monthly Trading Volume/ Shares Outstanding                            0.70%                  2.68%
</TABLE>


                                       33


<PAGE>   44


       This comparison indicated that Park trades at a premium to the Midwest
peer group as measured by market valuation. Average daily trading volume
indicates that approximately $318,000 worth of Park common shares have traded on
a daily basis during 2000.

COMPARABLE TRANSACTION ANALYSIS

       Based on the aggregate transaction value of $306.9 million, Austin
Associates calculated this value to be:

       -      250 percent of book value at September 30, 2000;
       -      275 percent of tangible book value at September 30, 2000; and
       -      17.8 times core net income for the last twelve months ended
              September 30, 2000.

       Austin Associates reviewed certain information relating to thirteen bank
sale transactions nationally announced from January 1, 2000 to November 17,
2000. The sale transaction bank peer group was selected based on all
transactions in which the selling company's assets ranged from $500 million to
$2 billion. The median asset size of the selling banks measured $1.1 billion.
Austin Associates compared the prices paid in these transactions as compared to
the transaction multiples being paid by Park for Security, and certain
underlying financial performance ratios of the selling banks as compared to
Security, as follows:

<TABLE>
<CAPTION>
                                                                                      MEDIAN COMPARABLE
                                                             PARK/SECURITY               TRANSACTION
                                                             -------------               -----------

<S>                                                           <C>                       <C>
    Price/Earnings Multiple                                      17.8 x                    19.3 x
    Price/Book Value Ratio                                        250%                      260%
    Price/Tangible Book Value Ratio                               275%                      260%
    Leverage Ratio                                               11.87%                     7.04%
    Return on Average Assets                                     1.76%                      1.15%
    Return on Average Equity                                     14.45%                    15.23%
    5-Year Average E.P.S. Growth Rate                             7.6%                      10.9%
</TABLE>

       The multiples being paid by Park for Security approximate the median
multiples paid for similarly sized banks during 2000.

CONTRIBUTION ANALYSIS

       Austin Associates compared the pro forma ownership interest in Park that
Security shareholders would receive, in the aggregate, to Security's
contribution of selected balance sheet, income statement and market
capitalization measures. The following table compares the range of pro forma
ownership of Security and Park shareholders in the combined corporation, based
upon the estimated exchange ratio of .2844, with each corporation's respective
contribution of various selected measures:

<TABLE>
<CAPTION>
                                                                                                       Ratio of
                                                                                                    Ownership to
                                                               Security              Park            Contribution
                                                               --------              ----            ------------

<S>                                                           <C>                   <C>              <C>
                    PRO FORMA OWNERSHIP                         23.7%               76.3%                100%

                     INCOME STATEMENT                                % Contribution
                                                                     ---------------
   1999 Actual Core Net Income                                  26.0%               74.0%                91.0%
   September 30, 2000 Core Net Income                           23.5%               76.5%               101.4%

          BALANCE SHEET AS OF SEPTEMBER 30, 2000
   Total Assets                                                 23.5%               76.5%               100.8%
   Total Deposits                                               23.4%               76.6%               101.1%
   Tangible Shareholders' Equity                                27.6%               72.4%               85.8%
</TABLE>


                                       34


<PAGE>   45


<TABLE>
<CAPTION>
                                                                                                       Ratio of
                                                                                                    Ownership to
                                                               Security              Park            Contribution
                                                               --------              ----            ------------
<S>                                                           <C>                 <C>                 <C>
           MARKET CAPITALIZATION
   Based on 30 Day Average Closing Price                        17.1%               82.9%               138.6%
   Based on 5 Day Average Closing Price                         17.6%               82.5%               134.9%
   Based on November 20, 2000 Closing                           17.7%               82.3%               133.9%
</TABLE>

PRO FORMA MERGER ANALYSIS

       Austin Associates also reviewed the pro forma effect of the proposed
transaction to Security's and Park's September 30, 2000 year-to-date earnings
per share and book value per share. Austin Associates calculated the pro forma
effect using the estimated .2844 exchange ratio.

       Security recorded diluted core earnings per share of $1.08 for the nine
months ended September 30, 2000 and Park's earnings measured $3.90 per share for
the same period. Giving effect to the merger, the equivalent Security earnings
would have equaled $1.11 per share, an increase of 2.4 percent from actual
results.

       Security's tangible book value per share equaled $9.47 as of September
30, 2000 and Park's tangible book value measured $27.13 per share. Giving effect
to the merger, the equivalent Security tangible book value would have equaled
$8.14 per share, a decrease of 14.1 percent from actual results.

       Park's pro forma year-to-date earnings per share would have equaled
$3.89, a decrease of 0.3 percent from actual results. Park's September 30, 2000
pro forma tangible book value per share would have equaled $28.60, an increase
of 5.4 percent from actual results.

PRO FORMA EQUIVALENT DIVIDENDS

       Austin Associates reviewed the current cash dividends paid by Park and
Security. Based on the exchange ratio of .2844, equivalent dividends to
Security's shareholders would have equaled $0.74 for the twelve months ended
September 30, 2000, compared to actual dividends of $0.58 per share. The current
quarterly dividend rate of Park is $0.65 per share, or $2.60 per share on an
annualized basis. Equivalent dividends to Security shareholders would equal
$0.74 annually, assuming an estimated .2844 exchange ratio. This represents a
27.6 percent increase over the last twelve months dividend rate of Security.

ADDITIONAL LIMITING CONDITIONS

       The opinion expressed by Austin Associates was based on market, economic
and other relevant considerations as they existed and could be evaluated as of
November 20, 2000. Events occurring after the date of issuance of the opinion,
including but not limited to, changes affecting the securities markets, the
results of operations or material changes in the financial condition of either
Park or Security could materially affect the assumptions used in preparing this
opinion.

       Security has agreed to pay Austin Associates $450,000 for its services in
issuing its fairness opinion in connection with the merger. In addition to its
fees and regardless of whether the merger is consummated, Security has agreed to
reimburse Austin Associates for its reasonable out-of-pocket expenses, and to
indemnify Austin Associates against certain liabilities, including liabilities
under securities laws.

       THE FULL TEXT OF THE AUSTIN ASSOCIATES OPINION LETTER, WHICH DESCRIBES
THE ASSUMPTIONS MADE AND MATTERS CONSIDERED, IS ATTACHED TO THIS DOCUMENT AS
APPENDIX B. WE URGE YOU TO READ THIS OPINION LETTER IN ITS ENTIRETY. AUSTIN
ASSOCIATES' OPINION IS DIRECTED ONLY TO THE CONSIDERATION TO BE RECEIVED BY
SECURITY SHAREHOLDERS IN THE MERGER AND DOES NOT CONSTITUTE A RECOMMENDATION AS
TO HOW THE SECURITY SHAREHOLDERS SHOULD VOTE AT THE SECURITY SPECIAL MEETING.


                                       35


<PAGE>   46


EFFECT ON OUTSTANDING PARK COMMON SHARES AND EXCHANGE OF SECURITY COMMON SHARES

EFFECT ON OUTSTANDING PARK COMMON SHARES

       Each issued and outstanding Park common share will continue to be one
Park common share after consummation of the merger.

EXCHANGE OF SECURITY COMMON SHARES

       At the effective time of the merger, all Security common shares that are
held by Security as treasury shares will be canceled and retired and no Park
common shares or other consideration will be delivered in exchange for those
Security common shares. All Security common shares held by Park will become
treasury shares of Park following the merger. All of the remaining Security
common shares, other than those as to which the holders have properly exercised
dissenters' rights, will be converted into Park common shares.

       The exact number of Park common shares to be received for each
outstanding Security common share, is determined by dividing 3,350,000 Park
common shares by the number of Security common shares outstanding immediately
prior to the effective time of the merger. At [     ], 2001, there were
[11,777,700] Security common shares outstanding. The merger agreement prohibits
Security from issuing any additional common shares, except for the [174,999]
Security common shares that are subject to outstanding options. If necessary,
the exchange ratio will be proportionately adjusted to prevent dilution as a
result of a share split, share dividend, recapitalization or similar transaction
with respect to the outstanding Park common shares prior to the effective date
of the merger.

       If both of the following conditions are met, Security may elect to
terminate the merger agreement at any time during the three-day period beginning
with the determination date for the merger. The determination date for the
merger is the last day of the 20 trading day period immediately preceding the
tenth day prior to the effective time of the merger:

       -      the average of the closing sale prices of a Park common share on
              the American Stock Exchange for the 20 trading day period
              immediately preceding the tenth day prior to the effective time of
              the merger must be less than $77.50, and

       -      the ratio of that 20 trading day average closing sales price to
              $91.375, the closing price of a Park National common share on the
              American Stock Exchange on November 20, 2000, must be less than
              the number obtained by dividing:

              -      the sum of the average daily closing sales prices of a
                     share of common stock for the 20 trading day period
                     immediately preceding the tenth day prior to the effective
                     time of the merger of each company comprising an index
                     group of ten similar bank holding companies (multiplied by
                     a designated weight), by

              -      the sum of each per share closing price of a share of
                     common stock of each index group company (multiplied by a
                     designated weight) on November 20, 2000.

       Before making any decision to terminate the merger agreement as a result
of the events described above, the Security board of directors will consult with
its financial and other advisors and will consider all financial and other
information it deems relevant to its decision. The Security board of directors
is under no obligation to resolicit the Security shareholders in the event
Security elects to exercise its termination right in connection with the
occurrence of any of the above-described events. The Security board of directors
will make its decision regarding resolicitation of the shareholders based on the
market conditions and other circumstances relating to the merger existing at the
time. For more information, see "The Merger Agreement - Amendment and
Termination" on page [   ].


                                       36


<PAGE>   47


NO FRACTIONAL PARK COMMON SHARES TO BE ISSUED

       Park will not issue scrip or fractional interests in Park common shares
in the merger. In lieu of fractional interests, Park will pay the cash value of
the fraction to each holder of Security common shares who otherwise would have
been entitled to a fraction of a Park common share, upon surrender of the
holder's certificates representing Security common shares. The shareholder will
receive an amount of cash, rounded to the nearest cent, determined by
multiplying the fractional share interest by the market value of a Park common
share. The market value of a Park common share will equal the average closing
price of a Park common share for the 20 trading day period immediately preceding
the tenth day prior to the effective time of the merger, as reported on the
American Stock Exchange.

CLOSING OF SECURITY SHARE TRANSFER BOOKS; EXCHANGE OF CERTIFICATES EVIDENCING
SECURITY COMMON SHARES

       Security will close its share transfer books in respect of the Security
common shares at the effective time of the merger.

       As soon as practicable after the effective time of the merger, each
Security shareholder will be advised of the effectiveness of the merger by
letter accompanied by a letter of transmittal and instructions for use to
surrender the certificate or certificates representing Security common shares to
Park's exchange agent, First-Knox National Bank.

       The letter of transmittal will be used to exchange Security certificates
for Park common shares and cash in lieu of any fractional share interest. If any
certificate representing Park common shares is to be issued in a name other than
that in which the Security certificate surrendered for exchange is registered,
the certificate so surrendered must be properly endorsed or otherwise in proper
form for transfer and the person requesting the exchange must pay to Park or
First-Knox National Bank, any applicable transfer or other taxes required by
reason of the issuance of the Park certificate. With respect to any
uncertificated Security common shares, First-Knox National Bank will issue
certificates representing the number of whole Park common shares (plus any cash
in lieu of fractional Park common shares) into which such uncertificated
Security common shares have been converted upon receipt of evidence of ownership
satisfactory to First-Knox National Bank. CERTIFICATES FOR SECURITY COMMON
SHARES SHOULD NOT BE FORWARDED TO FIRST-KNOX NATIONAL BANK UNTIL AFTER RECEIPT
OF THE LETTER OF TRANSMITTAL AND SHOULD NOT BE RETURNED TO SECURITY WITH THE
ENCLOSED PROXY CARD.

RIGHTS OF HOLDERS OF SECURITY SHARE CERTIFICATES PRIOR TO SURRENDER

       Upon surrender to First-Knox National Bank of Security certificates and a
properly completed letter of transmittal, the holder of the Security
certificates will be entitled to receive in exchange for the Security
certificates a certificate or certificates representing the Park common shares,
and cash in lieu of any resulting fractional share interest, to which the holder
is entitled. Unless and until the shareholder surrenders the Security
certificates together with a properly completed letter of transmittal, no
dividend payable to holders of record of Park common shares as of any time after
the effective time of the merger will be paid to that holder. Upon surrender of
the holder's outstanding Security certificates to First-Knox National Bank
together with a properly completed letter of transmittal, the former Security
shareholder will receive the dividends, without interest, that have become
payable as of that time with respect to the Park common shares to be issued upon
surrender and conversion.

LOST SHARE CERTIFICATES

       Any Security shareholder who has lost or misplaced a certificate for any
of the holder's Security common shares should immediately call J. William
Stapleton at (937) 324-6916 for information regarding the procedures to be
followed in order to obtain Park common shares in exchange for the holder's
Security common shares.

TREATMENT OF OUTSTANDING SECURITY OPTIONS

       As of [      ], 200[ ], there were [    ] unexercised Security stock
options outstanding covering an aggregate of [174, 999] Security common shares.
Each option to acquire Security common shares outstanding and


                                       37


<PAGE>   48


unexercised immediately prior to the effective time of the merger will be
converted automatically upon the completion of the merger into an option to
purchase Park common shares, with the following adjustments:

       -      the number of Park common shares subject to the converted options
              will be equal to the number of Security common shares subject to
              the original option multiplied by the exchange ratio of .2844; and

       -      the exercise price per Park common share subject to the converted
              option will be equal to the exercise price under the original
              Security option divided by the exchange ratio of .2844.

       The other terms and conditions of each converted option will be the same
as the original Security option. In any event, options that are incentive stock
options under the Internal Revenue Code will be adjusted in the manner
prescribed by the Internal Revenue Code.

ACCOUNTING TREATMENT OF THE MERGER

       The merger, if completed as proposed, will qualify as a
pooling-of-interests for accounting and financial reporting purposes. Under the
pooling-of-interests method of accounting, the historical basis of the assets
and liabilities of Park and Security will be retroactively combined for the
entire fiscal period in which the merger occurs and for all periods prior to the
merger at historically recorded amounts.

       The obligations of Park and Security to effect the merger are
conditioned, among other things, upon their receipt from their independent
auditors of letters, dated the closing date of the merger, to the effect that,
for financial reporting purposes, the merger qualifies for pooling-of-interests
accounting treatment under generally accepted accounting principles if
consummated in accordance with the merger agreement. For more information, see
"The Merger Agreement - Conditions to the Consummation of the Merger" on page
[     ]. The merger agreement further provides that neither Park nor Security
will intentionally take or cause to be taken any action, whether before or after
the effective time of the merger, which would disqualify the merger as a
pooling-of-interests for accounting purposes.

FEDERAL INCOME TAX CONSEQUENCES OF THE MERGER

       Park and Security will receive an opinion of Vorys, Sater, Seymour and
Pease LLP as of the closing date to the effect that the merger will be treated
for federal income tax purposes as a reorganization within the meaning of
Section 368(a) of the Internal Revenue Code, Park and Security each will be
parties to that reorganization within the meaning of Section 368(b) of the
Internal Revenue Code, and accordingly, for federal income tax purposes:

       -      neither Park nor Security will recognize any gain or loss as a
              result of the merger;

       -      shareholders of Security who exchange their Security common shares
              solely for Park common shares in the merger will not recognize any
              gain or loss, except to the extent that those shareholders receive
              cash in lieu of a fractional share;

       -      payment of cash to a Security shareholder in lieu of fractional
              Park common shares should be treated as having been received by
              such Security shareholder either as a taxable dividend or as a
              distribution in partial redemption of the shareholder's Security
              common shares, in accordance with Section 302 of the Internal
              Revenue Code;

       -      the tax basis of Park common shares received by shareholders of
              Security who exchange all of their Security common shares solely
              for Park common shares in the merger will be the same as the tax
              basis of the Security common shares surrendered in exchange; and

       -      the holding period of the Park common shares received in the
              merger will include the holding period of Security common shares
              surrendered in exchange, provided the Security common shares were
              held as capital assets at the effective time of the merger.


                                       38


<PAGE>   49


       The merger agreement provides that neither Park nor Security will
intentionally take or cause to be taken any action, whether before or after the
effective time of the merger, which would disqualify the merger as a
reorganization within the meaning of Section 368(a) of the Internal Revenue
Code. Vorys, Sater, Seymour and Pease LLP will base its opinion on facts,
representations and assumptions set forth in the opinion, the merger agreement
and certificates of officers of Security and Park, which will not have been
independently investigated or verified.

       THE FOREGOING DISCUSSION DOES NOT ADDRESS THE TAX CONSEQUENCES OF THE
MERGER TO PARK AND SECURITY SHAREHOLDERS WHO PERFECT DISSENTERS' RIGHTS. FOR
MORE INFORMATION, SEE "RIGHTS OF DISSENTING SHAREHOLDERS" ON PAGE [ ].

       THIS DISCUSSION DOES NOT ADDRESS THE STATE, LOCAL OR FOREIGN TAX ASPECTS
OF THE MERGER OR THE TAX CONSEQUENCES OF THE MERGER TO SHAREHOLDERS WHO MAY BE
SUBJECT TO SPECIAL RULES, INCLUDING, FOR EXAMPLE, FOREIGN SHAREHOLDERS. THIS
DISCUSSION IS BASED ON CURRENTLY EXISTING PROVISIONS OF THE INTERNAL REVENUE
CODE, EXISTING AND PROPOSED TREASURY REGULATIONS UNDER THE INTERNAL REVENUE CODE
AND CURRENT ADMINISTRATIVE RULINGS AND COURT DECISIONS. THE OPINION OF COUNSEL
DESCRIBED ABOVE IS NOT BINDING UPON THE INTERNAL REVENUE SERVICE, AND THE
PARTIES WILL NOT SEEK OR OBTAIN ANY RULINGS OF THE INTERNAL REVENUE SERVICE.
PARK AND SECURITY CAN PROVIDE NO ASSURANCE THAT THE INTERNAL REVENUE SERVICE
WILL AGREE WITH THE TAX CONSEQUENCES OF THE MERGER DESCRIBED ABOVE. ALL OF THE
FOREGOING IS SUBJECT TO CHANGE AND ANY CHANGE COULD AFFECT THE CONTINUING
VALIDITY OF THIS DISCUSSION. THE FOREGOING DISCUSSION MAY NOT BE APPLICABLE TO A
SECURITY SHAREHOLDER WHO ACQUIRED SECURITY COMMON SHARES UPON EXERCISE OF AN
EMPLOYEE STOCK OPTION OR OTHERWISE AS COMPENSATION. PARK AND SECURITY URGE THEIR
RESPECTIVE SHAREHOLDERS TO CONSULT THEIR OWN TAX ADVISORS CONCERNING THE
SPECIFIC TAX CONSEQUENCES OF THE MERGER TO THEM, INCLUDING THE APPLICABILITY AND
EFFECT OF FEDERAL, STATE, LOCAL AND OTHER TAX LAWS AND ANY PROPOSED CHANGES IN
THOSE TAX LAWS.

INTERESTS OF PERSONS IN THE MERGER

       Park has agreed to indemnify each of the officers, directors and
employees of Security and each Security subsidiary to the full extent Security
or any Security subsidiary would have been required to indemnify that individual
under Ohio law and the governing documents of Security and the Security
subsidiaries. The merger agreement also provides for the continuation of
director and officer liability insurance for these individuals for a period of
three years. For more information, see "The Merger Agreement - Costs and
Expenses; Indemnification" on page [  ] and "Comparison of Rights of Holders of
Park Common Shares and Holders of Security Common Shares - Director and Officer
Liability and Indemnification" on page [  ].

       In addition, Park has agreed to take all actions necessary to ensure that
each participant in Security's split dollar insurance benefit program will
continue to receive the vested portion of the participant's death benefits
following completion of the merger. Also, if Park ceases to maintain Security's
pension plan, Park has agreed to provide each participant in the Security
pension plan who becomes a participant in the Park pension plan with the same
accrued benefits that the participant has earned under Security's pension plan.
Each participant in Security's pension plan who becomes a participant in Park's
pension plan will be entitled to receive the higher of:

       -      a benefit consisting of a benefit computed under the Security
              pension plan formula for the period of participation before the
              merger plus a benefit computed under the Park pension plan formula
              for the period of participation after the merger; or

       -      a benefit computed by using the Park pension plan formula for the
              combined period of participation in the Security pension plan and
              the Park pension plan.

       Security National Bank has entered into employment agreements with three
of its executive officers, Harry O. Egger, J. William Stapleton and William C.
Fralick. Third Savings has entered into a similar agreement with Scott A.
Gabriel, one of its executive officers, and Citizens National Bank has entered
into a similar employment agreement with James R. Wilson, one of its executive
officers. The employment agreements provide for the continuation of the
individual's salary and benefits for the remaining term of the employment
agreement if his employment is terminated without cause or by reason of his
disability. If the individual dies during his term of


                                       39


<PAGE>   50



employment, his estate or other beneficiary will be entitled to receive his
salary through the last day of the calendar month in which the individual died
as well as a pro-rata annual incentive award for the fiscal year of his death.
If Mr. Egger's employment is terminated other than for cause, he will receive an
annual supplemental retirement benefit payable for the remainder of his life. If
Mr. Egger retires after reaching age 65 or his employment is terminated
following a change in control, the annual benefit payable is $153,320. If Mr.
Egger retires prior to age 65, the annual benefit is a reduced amount based upon
his age at the time of retirement.

       The employment agreements also provide for the payment of a lump sum
severance benefit if an individual's employment is terminated other than for
cause or by reason of his death or disability within twelve months following a
change in control of Security or the Security subsidiary employing the
individual. In the case of Mr. Egger, the amount of the severance benefit is
three times his annual salary as of the termination date. In the case of each of
Messrs. Stapleton, Fralick, Gabriel and Wilson, the amount of the severance
benefit is two times his annual salary as of the termination date. As of the
date of this joint proxy statement/prospectus, the annual salaries of Messrs.
Egger, Stapleton, Fralick, Gabriel and Wilson are $400,000, $175,000, $175, 000,
$152,000 and $192,000, respectively. In addition, to the extent the relevant
individual is not vested in any retirement plan, he will become fully vested and
payment from any qualified defined benefit retirement plan will be made as if
the individual had 24 additional months of service and 24 additional months of
age (36 additional months in the case of Mr. Egger). Messrs. Stapleton, Fralick,
Gabriel and Wilson would also be entitled to the payment of $35,000 for the
purpose of out-placement services.

       The obligation of Park to consummate the merger is subject to the
conditions that Mr. Egger's employment agreement be amended to provide that its
term will end on the third anniversary of the closing date of the merger and
that Messrs. Stapleton, Fralick, Wilson and Gabriel's employment agreements be
amended to provide that their terms will end on the second anniversary of the
closing date of the merger.

       Mr. Wilson is party to another agreement with Citizens National Bank
under which he is entitled to receive annual cash payments of $50,000 (payable
in monthly installments) for a period of ten years following his retirement
after reaching age 65. If he dies prior to his retirement, Mr. Wilson's wife
will receive annual cash payments of $75,000 (payable in monthly installments)
for a period of ten years. If Mr. Wilson elects to retire before age 65 but
after age 50, his retirement benefits under this agreement will be reduced based
on the ratio of the number of months worked since November 20, 1990 to 170
months. If Mr. Wilson becomes totally and permanently disabled prior to reaching
age 65, he will receive $1,556.88 monthly during the period following
satisfaction of a three-month waiting period until he reaches age 65.

       All of the individuals who have entered into employment agreements with a
subsidiary of Security are also executive officers of Security. Messrs. Egger,
Gabriel and Wilson also serve as directors of Security.

       Each option to purchase Security common shares that is outstanding
immediately before the merger is completed will be converted into an option to
buy Park common shares as described above under "Effect on Outstanding Park
Common Shares - Treatment of Outstanding Security Options." As of the date of
this joint proxy statement/prospectus, Harry O. Egger held in-the-money options
covering 14,000 Security common shares with exercise prices of $16.50; William
C. Fralick held in-the-money options covering 14,000 Security common shares with
exercise prices of $16.50; and J. William Stapleton held in-the-money options
covering 8,400 Security common shares with exercise prices of $16.50.

RESALE OF PARK COMMON SHARES RECEIVED IN THE MERGER

       The Park common shares that will be issued if the merger is consummated
have been registered under the Securities Act and will be freely transferable.
However, common shares of Park received by any person who is deemed to be an
"affiliate" (as that term is defined under the Securities Act of 1933) of
Security prior to the merger or of Park after the merger may be resold by that
person only in compliance with the volume and manner-of-sale requirements of
Rules 144 and 145 under the Securities Act. Affiliates of Park will be governed
by the additional provisions of Rule 144. Affiliates of Security or Park
generally include individuals or entities that control, are controlled by, or
are under common control with, that corporation and may include certain officers
and directors of that corporation as well as principal shareholders of that
corporation.


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<PAGE>   51


       Security has obtained written agreements from all directors, officers and
affiliates of Security not to dispose of their Park common shares in a manner
that would adversely affect the ability of Park to treat the merger as a
pooling-of-interests for financial accounting purposes.

       PERSONS WHO MIGHT BE DEEMED AFFILIATES OF SECURITY SHOULD CONSULT WITH
THEIR LEGAL ADVISORS PRIOR TO MAKING ANY OFFER OR SALE OF PARK COMMON SHARES
RECEIVED IN THE MERGER.

REGULATORY APPROVALS

       Consummation of the merger is subject to prior receipt by Park and
Security of all necessary regulatory approvals. The principal regulatory
approval required to be obtained is from the Federal Reserve Board. A bank
holding company merger application was filed with the Federal Reserve Board on
January 2, 2001. The required notice filing with the OTS will be made in
accordance with the regulations of the OTS.

       Park will file an application with the American Stock Exchange to list
the Park common shares to be issued in the merger.

       The approval of an application means only that the regulatory criteria
for approval have been satisfied or waived. It does not mean that the approving
authority has determined that the consideration to be received by Security
shareholders is fair. Regulatory approval does not constitute an endorsement or
recommendation of the merger.

       Park and Security will not complete the merger before they receive all
requisite regulatory approvals and all applicable waiting periods have expired
and any conditions imposed in the regulatory approvals have been complied with.
Park and Security cannot guarantee that they will obtain all approvals or that
those approvals will not impose conditions which would have a material adverse
effect on the business, operations, assets or financial condition of Park and
the Park subsidiaries taken as a whole or otherwise materially impair the value
to Park of Security and the Security subsidiaries as a whole. If the Federal
Reserve Board imposes this type of condition, the merger agreement permits the
boards of directors of Park and Security to abandon the merger.

       Park and Security cannot assure you as to when, or if, they will obtain
necessary regulatory approvals. If the merger is not completed by October 31,
2001, either Park or Security may terminate the merger agreement. For more
information, see "The Merger Agreement - Amendment and Termination" on page [ ].

EXISTING RELATIONSHIP BETWEEN PARK AND SECURITY

       Except in connection with the merger agreement and the transactions
contemplated by the merger agreement, Security has not conducted business with,
nor has it had any business relationship with, Park prior to the transactions
described in the merger agreement. As of December 15, 2000, Park owned 15,000
Security common shares and none of Park's affiliates owned any Security common
shares.

                              THE MERGER AGREEMENT

THE MERGER

       The merger agreement provides that, subject to the adoption of the merger
agreement by the shareholders of Park and Security and the satisfaction or
waiver of the other conditions to the merger, Security will merge into Park.
Following completion of the merger, Security will no longer exist as a separate
corporation. The merger agreement provides for Park and Security to implement
the merger by causing a certificate of merger to be filed with the Ohio
Secretary of State, consistent with the applicable provisions of the merger
agreement.

       The material provisions of the merger agreement are briefly summarized
below. This summary does not purport to be complete and is qualified in its
entirety by reference to the complete text of the merger agreement, which is
reprinted as Appendix A to this joint proxy statement/prospectus and
incorporated in this joint proxy statement/prospectus by this reference. Park
and Security urge you to read the merger agreement in its entirety for a more
complete description of the merger.


                                       41
<PAGE>   52


CONVERSION OF SECURITY COMMON SHARES

       At the effective time of the merger, each Security common share
outstanding immediately prior to the effective time of the merger, other than
those as to which dissenters' rights are perfected, will be converted into
approximately .2844 Park common shares. All Security common shares owned by
Security as treasury shares will be canceled and retired, and no Park common
shares or other consideration will be delivered in exchange for those shares.
All Security common shares owned by Park will become treasury shares of Park.
For more information, see "The Merger - Effect on Outstanding Park Common Shares
and Exchange of Security Common Shares" on page [  ].

REPRESENTATIONS AND WARRANTIES

       In the merger agreement, Security has made representations and warranties
concerning the following items:

       -      due organization, good standing and authority to carry on business
              of Security and its subsidiaries;
       -      capital structure of Security;
       -      status of Security National Bank, Citizens National Bank and Third
              Savings;
       -      corporate power and authority to enter into the merger agreement
              and consummate the merger and enforceability of the merger
              agreement and related matters;
       -      financial statements and reports and absence of undisclosed
              liabilities;
       -      absence of any material adverse change to Security or its
              subsidiaries;
       -      loans;
       -      allowance for loan losses;
       -      regulatory reports and records filed by Security and its
              subsidiaries;
       -      taxes of Security and its subsidiaries;
       -      property of Security and its subsidiaries;
       -      legal proceedings involving Security or its subsidiaries;
       -      absence of regulatory proceedings involving Security or its
              subsidiaries;
       -      absence of conflicts of the merger agreement with applicable laws,
              contracts and corporate documents;
       -      commissions, finder's fees or similar payments payable only to
              Austin Associates;
       -      employment agreements and compliance with employment laws;
       -      employee benefit plans and compliance with provisions of the
              Employee Retirement Income Security Act of 1974;
       -      compliance with laws;
       -      accuracy and completeness of information supplied by Security for
              inclusion in the registration statement on Form S-4 of which this
              joint proxy statement/prospectus is a part;
       -      insurance;
       -      required governmental and third-party proceedings in connection
              with the merger;
       -      material contracts and absence of defaults;
       -      environmental matters;
       -      absence of actions that would prevent the merger from being
              accounted for as a pooling-of-interests;
       -      compliance with takeover laws;
       -      risk management instruments;
       -      complete and accurate books and records;
       -      repurchase agreements;
       -      accuracy of representations and warranties;
       -      title to investment securities held by Security and its
              subsidiaries;
       -      reports and records filed by Security with the SEC;
       -      compliance with fiduciary responsibilities with respect to the
              administration of accounts;
       -      compliance with the Federal Community Reinvestment Act;
       -      ownership of Park common shares; and
       -      receipt of an opinion of Austin Associates that the consideration
              to be received by Security shareholders in the merger is fair.


                                       42


<PAGE>   53


       Park has made representations and warranties concerning the following
items:

       -      Park's due organization, good standing and authority to carry on
              business;
       -      corporate power and authority to enter into the merger agreement
              and consummate the merger and enforceability of the merger
              agreement and related matters;
       -      capitalization of Park;
       -      absence of conflicts of the merger agreement with applicable laws,
              contracts and corporate documents;
       -      financial statements and reports;
       -      absence of any material adverse change to Park and its
              subsidiaries;
       -      compliance with takeover laws;
       -      reports and records filed by Park with the SEC;
       -      no commissions, finder's fees or similar payments;
       -      required governmental and third-party proceedings in connection
              with the merger;
       -      absence of actions that would prevent the merger from being
              accounted for as a pooling-of-interests;
       -      accuracy and completeness of information supplied by Park in the
              registration statement on Form S-4 of which this joint proxy
              statement/prospectus is a part;
       -      deposit insurance;
       -      accuracy of representations and warranties; and
       -      ownership of Security common shares.

       Park and Security believe that the representations and warranties
contained in the merger agreement are customary in transactions similar in
nature to the merger. For more information, see Articles Three and Four of the
merger agreement, which is attached as Appendix A to this document.

CONDUCT OF BUSINESS PENDING THE MERGER

       The merger agreement requires Security to conduct its business and the
business of each of its subsidiaries in the ordinary and usual course consistent
with past practice. Under this covenant, the merger agreement specifically
prohibits Security from:

       -      taking any action which would be inconsistent with any
              representation or warranty of Security in the merger agreement;
              and

       -      engaging in any lending activities other than in the ordinary
              course of business consistent with past practice.

       The merger agreement also requires Security not to take, and to cause
each of its subsidiaries not to take, any of the following actions without the
consent of Park:

       -      selling, transferring, mortgaging, pledging, encumbering or
              subjecting to any lien, any of the assets of Security or its
              subsidiaries, except in the ordinary course of business for full
              and fair consideration;

       -      making any capital expenditure or capital additions or betterments
              which individually exceed $100,000;

       -      becoming bound by, entering into, or performing any material
              contract or commitment which is other than in the ordinary course
              of its business or which would cause or result in Security being
              unable to perform its obligations under the merger agreement;

       -      declaring, paying or setting aside for payment any dividends or
              making any distributions on its capital shares other than
              quarterly cash dividends on Security common shares for fiscal
              quarters ending on or after December 31, 2000 in an amount not to
              exceed $0.20 per share;

       -      purchasing, redeeming, retiring or otherwise acquiring any of its
              common shares;


                                       43


<PAGE>   54


       -      issuing or granting any option or right to acquire any of its
              shares or any bonds, debentures, notes or other indebtedness
              having the right to vote on any matters on which shareholders of
              Security may vote;

       -      effecting any split, recapitalization, combination, exchange of
              shares, readjustment or other share reclassification;

       -      amending its governing documents;

       -      merging or consolidating with any other person or otherwise
              reorganizing, except for the merger;

       -      acquiring all or any portion of, the assets, business, deposits or
              properties of any other entity, except by way of foreclosures or
              acquisitions of control in a bona fide fiduciary capacity or in
              satisfaction of debts previously contracted in good faith, in the
              ordinary course of business and consistent with past practices;

       -      entering into, establishing, adopting or amending any pension,
              retirement, stock option, stock purchase, savings, profit sharing,
              deferred compensation, consulting, bonus, group insurance or other
              employee benefit, incentive or welfare contract, plan or
              arrangement, or any trust agreement, or similar arrangement,
              related to the plan or arrangement, in respect of any director,
              officer or employee of Security or its subsidiaries, or taking any
              action to accelerate the vesting or exercisability of stock
              options, restricted stock or other compensation or benefits
              payable under those plans or arrangements. Security, however, may:

              -      take any of these actions in order to satisfy either
                     applicable law or previously disclosed contractual
                     obligations existing as of November 20, 2000 or regular
                     annual renewal of insurance contracts; and

              -      terminate its defined contribution retirement plan at any
                     time before the effective time of the merger, with benefit
                     distributions deferred until the Internal Revenue Service
                     issues a favorable determination with respect to the
                     terminating plan's tax-qualified status upon termination.
                     In this event, Security and Park will cooperate in good
                     faith to apply for approval and to agree upon associated
                     plan termination amendments that will, among other things,
                     provide for the application of all assets of a terminating
                     plan for its participants, and allow plan participants not
                     only to receive lump-sum distributions of their benefits,
                     but also to transfer those benefits to the Park 401(k) plan
                     that Park maintains for its employees and employees of its
                     subsidiaries;

       -      paying any general wage or salary increase or bonus, other than
              normal pay increases and bonuses consistent with past practices,
              or entering into or amending or renewing any employment,
              consulting, severance or similar agreements or arrangements with
              any officer, director or employee, except, in each case, for
              changes required by law or to satisfy previously disclosed
              contractual obligations existing as of November 20, 2000;

       -      entering into or terminating any contract, other than a loan
              contract, requiring the payment or receipt of $100,000 or more in
              any 12-month period or amending or modifying in any material
              respect any of its existing material contracts;

       -      incurring any indebtedness for money borrowed or incurring any
              material obligation or liability other than in the ordinary course
              of business;

       -      taking any action that would, or is reasonably likely to, prevent
              or impede the merger from qualifying for pooling-of-interest
              accounting or as a reorganization with the meaning of Section
              368(a) of the Internal Revenue Code;

       -      implementing or adopting any change in its accounting principles,
              practices or methods, other than as required by generally accepted
              accounting principles;


                                       44


<PAGE>   55


       -      waiving or canceling any right of material value or material
              debts, except in the ordinary course of business consistent with
              past practices;

       -      taking any action that would result in:

              -      any of its representations and warranties set forth in the
                     merger agreement being or becoming untrue in any material
                     respect at or prior to the effective time of the merger,

              -      any of the conditions to the merger not being satisfied, or

              -      a violation of any provision of the merger agreement,
                     except as required by law or regulation;

       -      causing any material adverse change in the amount or general
              composition of deposit liabilities;

       -      making any material investment, except in the ordinary course of
              business;

       -      except as required by applicable law or regulation:

              -      implementing or adopting any material change in its
                     interest rate risk management and other risk management
                     policies, procedures or practices,

              -      failing to follow its existing policies or practices with
                     respect to managing its exposure to interest rate and other
                     risk, or

              -      failing to use commercially reasonable means to avoid any
                     material increase in its aggregate exposure to interest
                     rate risk;

       -      taking any action or omitting to take any action which would
              terminate or enable an employee of Security or any of its
              subsidiaries to terminate his employment or employment agreement
              without cause and continue to receive compensation after
              termination of his employment; or

       -      entering into any agreement to do any of the foregoing.

       The merger agreement also requires Security and each of its subsidiaries
to:

       -      use commercially reasonable efforts to maintain their property and
              facilities in their present condition and working order, ordinary
              wear and tear excepted;

       -      perform all of their obligations under all agreements relating to
              or affecting their properties, rights and business, except where
              nonperformance would not have a material adverse effect;

       -      use commercially reasonable efforts to maintain and preserve their
              respective business organizations intact, retain present key
              employees and maintain the respective relationships of customers,
              suppliers and others having business relationships with them;

       -      maintain insurance coverage with reputable insurers, which in
              respect of amounts, premiums, types and risks insured, were
              maintained by them as of September 30, 2000, and upon the renewal
              or termination of that insurance, use commercially reasonable best
              efforts to renew or replace that insurance coverage with reputable
              insurers, which in respect of amounts, premiums, types and risks
              insured were maintained by them as of September 30, 2000;

       -      provide reasonable access by Park to information of Security and
              each of its subsidiaries;

       -      timely file all tax returns and pay any tax shown on those tax
              returns as due;


                                       45


<PAGE>   56


       -      deliver to Park, upon its specific request, title insurance
              commitments for title insurance policies for parcels of real
              property owned or leased by Security or any of its subsidiaries,
              each in an amount equal to the carrying cost of the real property
              interest to be insured as indicated in the books of Security or
              any of its subsidiaries;

       -      provide Park, upon its specific request, with current land surveys
              of parcels of real property owned or leased by Security or any of
              its subsidiaries; and

       -      promptly notify Park of the filing of any reports with the SEC by
              persons or entities who have acquired beneficial ownership of 5%
              or more of Security's common shares.

       The merger agreement requires each of Park and Security:

       -      to use their reasonable best efforts to take all actions necessary
              to satisfy all of the conditions to the merger, to comply with all
              applicable legal requirements, to make all necessary filings, to
              obtain all necessary governmental and third party consents and to
              otherwise consummate the merger;

       -      to take all necessary steps to exempt the agreement and the merger
              from the requirements of any takeover law and any provisions in
              their governing documents and to assist in any challenge to the
              validity or applicability to the merger of any takeover law;

       -      to notify the other party in writing if it becomes aware of any
              fact, condition or occurrence that would:

              -      cause or constitute a breach of any representation,
                     warranty or covenant in the merger agreement,

              -      make the satisfaction of the conditions in the agreement
                     unlikely or impossible,

              -      have a material adverse effect on the company providing the
                     notification, either individually or in the aggregate, with
                     other facts, conditions or occurrences, or

              -      in the case of Security, be required to be set forth in an
                     amendment to the registration statement on Form S-4 or a
                     supplement to this joint proxy statement/prospectus; and

       -      not to take any action subsequent to the date of the merger
              agreement that would adversely affect the ability of Park to treat
              the merger as a pooling-of-interests or the characterization of
              the merger as a tax-free reorganization under Section 368(a) of
              the Internal Revenue Code.

       Park also has agreed:

       -      to provide reasonable access by Security to information of Park
              and each of its subsidiaries;

       -      to file a listing application with the American Stock Exchange
              covering the Park common shares to be issued in the merger; and

       -      to indemnify the officers, directors and employees of Security and
              each of Security's subsidiaries and to provide certain employee
              benefits, as described below.

       Employees of Security and each of Security's subsidiaries will have the
opportunity to continue as employees of Park or one of its subsidiaries, subject
to the right of Park and its subsidiaries to terminate an employee for cause.
After the effective time of the merger, employees of Security and its
subsidiaries will continue to participate in the Security employee benefit plans
until Park determines that those employees will, subject to eligibility
requirements, participate in Park's employee benefit plans and that all or some
of the Security plans will be terminated or merged into Park's employee benefit
plans. Park will give employees of Security and its subsidiaries credit for
years of service for purposes of eligibility and vesting, but not for benefit
accrual purposes, in Park's employee benefit plans, and the


                                       46


<PAGE>   57


employees will not be subject to any exclusion or penalty for pre-existing
conditions that were covered under Security's welfare plans, or to any waiting
period relating to that coverage. In addition, if Park adopts a new plan or
program for its employees or executives, to the extent its employees or
executives receive past service credits for any reason, Park will credit
similarly-situated employees and executives of Security and its subsidiaries
with equivalent credit for service with Security, its subsidiaries and any of
their predecessors.

       Park and Security have agreed to coordinate the payment of dividends with
respect to the Park common shares and the Security common shares and the record
dates and payment dates relating to dividends.

CONDITIONS TO THE CONSUMMATION OF THE MERGER

       The obligation of each of Park and Security to consummate the merger is
subject to a number of conditions, including the following:

       -      the adoption of the merger agreement by the requisite vote of the
              Park shareholders and the Security shareholders;

       -      all necessary regulatory approvals have been obtained in
              connection with the merger and all statutory waiting periods have
              expired;

       -      no regulatory approvals contain any conditions, restrictions or
              requirements which Park reasonably determines would either before
              or after the effective time, have a material adverse effect on
              Park or prevent Park from realizing the economic benefits of the
              merger and related transactions;

       -      no court or other governmental or regulatory authority has
              enacted, issued, promulgated, enforced, threatened, commenced a
              proceeding with respect to, or entered, any statute, rule,
              regulation, judgment, decree, injunction or other order
              prohibiting or delaying consummation of the transactions
              contemplated by the merger agreement;

       -      the Form S-4 registration statement of which this joint proxy
              statement/prospectus forms a part has become effective and no stop
              order suspending the effectiveness of the registration statement
              has been issued or no proceedings for that purpose initiated or
              threatened by the SEC;

       -      all permits and other authorizations required under state
              securities laws to consummate the transactions contemplated by the
              merger agreement and issue the Park common shares to be issued in
              the merger have been received;

       -      Park has received from Ernst & Young LLP, Park's independent
              auditors, their opinion, dated the date of the closing date of the
              merger, that the merger qualifies for pooling-of-interests
              accounting treatment; and

       -      the Park common shares to be issued in the merger have been
              approved for listing on the American Stock Exchange.

       The obligation of Park to consummate the merger is also subject to a
number of additional conditions, including the following:

       -      the representations and warranties of Security contained in the
              merger agreement are true and correct in all material respects as
              of the closing of the merger, or in the case of representations
              and warranties made as of a specified date earlier than the
              closing date of the merger, on and as of that date, and Security
              has delivered a certificate to Park to that effect;

       -      Security has performed all obligations required by Security under
              the merger agreement and Security has delivered a certificate to
              Park to that effect;


                                       47


<PAGE>   58


       -      in the aggregate, less than 10% of the total number of common
              shares to be issued by Park National in the merger are subject to
              purchase as fractional share interests or the subject of
              dissenters' rights exercised by shareholders of Park or Security;

       -      Park has received the opinion of Vorys, Sater, Seymour and Pease
              LLP stating that the merger constitutes a tax-free
              "reorganization" within the meaning of Section 368(a) of the
              Internal Revenue Code;

       -      Park has received the opinion of Werner & Blank Co., L.P.A., legal
              counsel to Security, stating that:

              -      Security is a corporation duly incorporated and in good
                     standing under the laws of the State of Ohio;

              -      Security National Bank and Citizens National Bank are
                     national banking associations duly organized and in good
                     standing under the laws of the United States of America;

              -      Third Savings is an Ohio state-charted savings association
                     duly organized and in good standing under the laws of the
                     State of Ohio;

              -      all eligible accounts of deposit in Security National Bank,
                     Citizens National Bank and Third Savings are insured by the
                     Federal Deposit Insurance Corporation to the fullest extent
                     permitted by law;

              -      Security is a duly and validly registered bank holding
                     company under the Bank Holding Company Act;

              -      the merger agreement was duly approved by the Security
                     board of directors and duly adopted by the Security
                     shareholders;

              -      the merger agreement was duly executed by Security and,
                     with stated exceptions, constitutes the binding obligation
                     of Security and is enforceable in accordance with its terms
                     against Security;

              -      the merger does not conflict with the governing documents
                     of Security or any of its subsidiaries;

              -      Security has the authority to perform its obligations under
                     the merger agreement and to complete the transactions
                     contemplated by the merger agreement;

              -      Security and each of its subsidiaries have the authority to
                     own their properties and carry out their businesses;

              -      Werner & Blank has no knowledge of any pending or
                     threatened legal proceedings, claims or investigations
                     which would prevent the completion of the merger, declare
                     the merger to be unlawful or cause the merger to be
                     rescinded; and

              -      upon the filing of the certificate of merger with the
                     Secretary of State of Ohio, the merger will become
                     effective;

       -      Park has received a statement issued by Security pursuant to
              Section 1.897-2(h) of the regulations issued under the Internal
              Revenue Code certifying that the Security common shares are not
              U.S. real property interest;

       -      Security has obtained the consent or approval of each person,
              other than governmental and regulatory authorities, whose consent
              or approval is required to permit Park to succeed to any
              obligation, right or interest of Security or any of its
              subsidiaries under any loan or credit agreement, note, mortgage,


                                       48


<PAGE>   59


              indenture, lease, license or other agreement or instrument, except
              where the failure to obtain such a consent or approval would not
              have a material adverse effect on Park following the merger;

       -      The employment agreement between Harry O. Egger and Security
              National Bank is amended to provide that the employment agreement
              will end on the third anniversary of the closing date of the
              merger; and

       -      The employment agreements between J. William Stapleton and
              Security National Bank, William C. Fralick and Security National
              Bank, James R. Wilson and Citizens National Bank and Scott A.
              Gabriel and Third Savings are amended to provide that each
              employment agreement will end on the second anniversary of the
              closing date of the merger.

       The obligation of Security to consummate the merger is also subject to a
number of additional conditions, including the following:

       -      the representations and warranties of Park contained in the merger
              agreement are true and correct in all material respects as of the
              closing of the merger, or in the case of representations and
              warranties made as of a specified date earlier than the closing
              date of the merger, on and as of that date, and Park has delivered
              a certificate to Security to that effect;

       -      Park has performed all obligations required by Park under the
              merger agreement and Park has delivered a certificate to Security
              to that effect;

       -      Security has received the opinion of Vorys, Sater, Seymour and
              Pease LLP, legal counsel to Park, stating that the merger
              constitutes a tax free "reorganization" within the meaning of
              Section 368(a) of the Internal Revenue Code and no gain or loss
              will be recognized by shareholders of Security who receive Park
              common shares in exchange for Security common shares and cash in
              lieu of fractional share interests, other than the gain or loss to
              be recognized as to cash received in lieu of fractional share
              interests;

       -      Security has received the opinion of Vorys, Sater, Seymour and
              Pease LLP, legal counsel to Park, stating that:

              -      Park is a corporation duly incorporated and in good
                     standing under the laws of the State of Ohio;

              -      Park is a duly and validly registered bank holding company
                     under the Bank Holding Company Act;

              -      the merger agreement was duly approved by the Park board of
                     directors and duly adopted by the Park shareholders;

              -      the merger agreement was duly executed by Park and with
                     stated exceptions, constitutes the binding obligation of
                     Park and is enforceable in accordance with its terms
                     against Park;

              -      the merger will not conflict with Park's governing
                     documents;

              -      Park has the authority to perform its obligations under the
                     merger agreement and to complete the transactions
                     contemplated by the merger agreement;

              -      the common shares of Park to be issued as consideration in
                     the merger, when issued, will be duly authorized, fully
                     paid and non-assessable; and

              -      upon the filing of the certificate of merger with the
                     Secretary of State of Ohio, the merger will become
                     effective; and


                                       49


<PAGE>   60


       -      Park has obtained the consent or approval of each person, other
              than governmental and regulatory authorities, which is required in
              connection with the merger under any loan or credit agreement,
              note, mortgage, indenture, lease or other agreement or instrument,
              except for those that would not have a material adverse effect on
              Park if not obtained.

       Where the law permits, Park or Security could decide to complete the
merger even though one or more conditions was not satisfied. By law, neither
Park nor Security can waive (1) the condition of adoption of the merger
agreement by Park's or Security's shareholders or (2) any court order or law
having the effect of making illegal or otherwise prohibiting the consummation of
the merger. Whether any of the conditions would be waived would depend upon the
facts and circumstances as determined by the reasonable business judgment of the
board of directors of Park or Security.

EFFECTIVE TIME OF THE MERGER

       Upon satisfaction or waiver of all conditions under the merger agreement,
Park and Security will cause an appropriate certificate of merger to be filed
with the Ohio Secretary of State. The merger will become effective upon the
filing of the certificate of merger or at a time after the filing that Park and
Security agree to in writing and state in the certificate of merger. Park and
Security anticipate that the merger will be completed during the second quarter
of 2001.

       The closing of the transactions contemplated by the merger agreement will
take place on a day designated by Park which is not:

       -      earlier than the third business day after the last of the
              conditions described in the merger agreement has been satisfied or
              waived in accordance with the terms of the merger agreement, or

       -      later than the last business day of the month in which that third
              business day occurs.

However, the date chosen by Park may not fall after October 31, 2001 or after
the date or dates on which any regulatory authority approval or extension
expires. Park and Security are also free to agree to close the transactions on a
different date.

AMENDMENT AND TERMINATION

       Park and Security may amend the merger agreement at any time before or
after the Park special meeting or the Security special meeting. However, after
approval of the matters to be considered at the special meetings, Park and
Security may not make an amendment which by law requires further approval by the
Park shareholders or the Security shareholders, unless that further approval is
obtained.

       Park and Security may agree in writing to terminate the merger agreement
at any time before completion of the merger, even if the shareholders of both
Park and Security have adopted it.

       Either Security or Park may decide to terminate the merger agreement if:

       -      the merger has not been completed by October 31, 2001, unless the
              failure to complete the merger arises out of or results from the
              breach of the merger agreement by the party seeking to terminate;

       -      the shareholders of Security fail to adopt the merger agreement by
              the requisite vote at the Security special meeting of shareholders
              or an adjournment of the Security special meeting; or

       -      the shareholders of Park fail to adopt the merger agreement by the
              requisite vote at the Park special meeting of shareholders or an
              adjournment of the Park special meeting;

       -      a governmental authority fails to approve the merger.


                                       50


<PAGE>   61


       Park may decide to terminate the merger agreement if:

       -      Security breaches any representation and warranty in the merger
              agreement and does not cure the breach within 30 days following
              receipt of written notice of the breach or cannot cure the breach
              within that time, except that the breach individually or in the
              aggregate, must have or be reasonably likely to have a materially
              adverse effect; or

       -      Security fails to comply in any material respect with any covenant
              or agreement in the merger agreement within 30 days following
              receipt by Security of written notice of the breach or cannot cure
              the breach during that time.

       Security may decide to terminate the merger agreement if:

       -      Park breaches any representation and warranty in the merger
              agreement and does not cure the breach within 30 days following
              receipt of written notice of the breach, or cannot cure the breach
              within that time, except that the breach, individually or in the
              aggregate, must have or be reasonably likely to have a materially
              adverse effect;

       -      Park fails to comply in any material respect with any covenant or
              agreement in the merger agreement within 30 days following receipt
              by Park of written notice of the breach or cannot cure the breach
              during that time;

       -      Security determines, based on advice of its counsel, that
              termination is required for its board of directors to comply with
              its fiduciary duties to shareholders by reason of another
              acquisition proposal having been made, except that Security must
              not have otherwise breached its obligations to not solicit or
              initiate or knowingly encourage the acquisition proposal and to
              notify Park of any proposal and that Security must pay a
              termination fee of $10,000,000 to Park prior to termination;

       -      during the three-day period beginning with the determination date
              of the merger (the last day of the 20 trading day period
              immediately preceding the tenth day prior to the effective time of
              the merger), if both of the following conditions are satisfied:

              -      the average of the closing sales prices of a Park common
                     share on the American Stock Exchange for the 20 trading day
                     period immediately preceding the tenth day prior to the
                     effective time of the merger is less than $77.50, and

              -      the ratio of that 20 trading day average closing sales
                     price to $91.375 (the closing price of a Park common share
                     on the American Stock Exchange on November 20, 2000) is
                     less than the number obtained by dividing:

                     -      the sum of the average daily closing sales prices of
                            a share of common stock for the 20 trading day
                            period immediately preceding the tenth day prior to
                            the effective time of the merger of each company
                            comprising an index group of ten similar bank
                            holding companies (multiplied by a designated
                            weight), by

                     -      the sum of each per share closing price of a share
                            of common stock of each index group company
                            (multiplied by a designated weight) on November 20,
                            2000.

       In the event of termination, the merger agreement will become void except
that provisions regarding acquisition proposals of Security, confidentiality,
press releases, payment of fees and expenses, the accuracy and completeness of
information submitted to the SEC and the effect of the termination of the merger
agreement will survive termination.


                                       51


<PAGE>   62


ACQUISITION PROPOSALS

SECURITY

       Under specific circumstances, Security could be required to pay a special
fee to Park if the merger is not completed and Security enters into an agreement
with another party to acquire Security. In the merger agreement, Security has
agreed not to solicit or encourage the submission of any other acquisition
proposal by a third party. The board of directors of Security, however, may
terminate the merger agreement if another party submits a proposal to acquire
Security and the board determines in good faith that termination is required for
the board to comply with its fiduciary duties to Security's shareholders. If the
board of directors terminates the merger agreement for this reason, Security may
be required to pay Park a special termination fee of $10,000,000.

       If the merger agreement is terminated for a reason other than the receipt
by Security of an acquisition proposal from another party, then Security may
still be required to pay a $10,000,000 special fee to Park if Security enters
into an acquisition agreement with another party within one year after the
merger agreement is terminated. Security may be required to pay the fee only if:

       -      the acquisition agreement with the other party provides that
              shareholders of Security will receive at least $22.04 in
              consideration for each of their Security common shares; and

       -      the merger agreement was terminated for reasons other than:

              -      a breach of any representation and warranty of Park,

              -      failure of Park to comply in any material respect with its
                     covenants or agreements in the merger agreement,

              -      the average closing sale price of a Park common share, for
                     the 20 trading day period immediately preceding the tenth
                     day prior to the effective time of the merger, is less than
                     $77.50 and the ratio of the price decline for Park common
                     shares exceeds the ratio of the price decline for shares of
                     the common stock of a specific group of bank holding
                     companies,

              -      mutual written agreement of Park and Security,

              -      the merger has not closed by October 31, 2001, unless
                     Security caused the merger not to be completed for purposes
                     of pursuing an acquisition proposal from another party,

              -      the shareholders of Security do not adopt the merger
                     agreement, unless the board of directors of Security
                     announce their intention not to recommend the merger
                     agreement prior to the Security special meeting,

              -      the shareholders of Park do not adopt the merger agreement,
                     or

              -      the approval of any governmental or regulatory authority
                     required to complete the merger is denied.

PARK

       In the merger agreement, Park has agreed not to accept any offer from any
person to acquire Park unless the party who proposes to acquire Park agrees to
perform Park's obligations under the merger agreement.


                                       52


<PAGE>   63


COSTS AND EXPENSES; INDEMNIFICATION

       Whether or not the merger is consummated, all costs and expenses incurred
in connection with the merger agreement and the transactions contemplated by the
merger agreement will be paid by the party incurring those costs and expenses,
except that Park and Security will share all expenses incurred in connection
with filing, printing and mailing this joint proxy statement/prospectus equally
and Park will pay all fees due to regulatory authorities and the SEC in
connection with the transactions contemplated by the merger agreement.

       Park has agreed to indemnify the present officers, directors and
employees of Security and each Security subsidiary to the full extent Security
or any Security subsidiary would have been required to indemnify that person
under Ohio law and the governing documents of Security and the Security
subsidiaries. In addition, for a period of three years after the effective time
of the merger, Park will provide directors' and officers' liability insurance on
terms no less favorable than those in effect as of November 20, 2000, to
indemnify the present and former officers and directors of Security and the
Security subsidiaries with respect to claims against those individuals arising
from facts or events which occurred prior to the effective time of the merger.
Park will not be required to pay more than 200% of the amount spent by Security
as of November 20, 2000, in order to maintain or procure that insurance, but if
that limit is met, Park must use its reasonable best efforts to maintain or
obtain as much comparable insurance as can be obtained up to the 200% limit.

RECOMMENDATION AND VOTE

       The boards of directors of Park and Security believe that the
consummation of the proposed merger is in the best interest of their respective
corporations and their shareholders. The affirmative vote of the holders of
two-thirds of the outstanding Park common shares and the holders of two-thirds
of the outstanding Security common shares is required for the merger agreement
to be adopted.

       THE SECURITY BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT THE SECURITY
SHAREHOLDERS VOTE "FOR" THE ADOPTION OF THE MERGER AGREEMENT.

       THE PARK BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT THE PARK
SHAREHOLDERS VOTE "FOR" THE ADOPTION OF THE MERGER AGREEMENT.

                        RIGHTS OF DISSENTING SHAREHOLDERS

       The following is a description of the steps you must take to perfect
dissenters' rights with respect to the merger. The description is not intended
to be complete and is qualified in its entirety by reference to Section 1701.85
of the Ohio Revised Code, a copy of which is included as Appendix C to this
joint proxy statement/prospectus. We recommend that you consult with your own
counsel if you have questions with respect to your rights under the statute.

       "Dissenters' rights" is your right to dissent from the merger and to have
the "fair cash value" of your Park common shares or your Security common shares
determined by a court and paid in cash. The "fair cash value" of a Park or a
Security common share is the amount that a willing seller who is under no
compulsion to sell would be willing to accept and that a willing buyer who is
under no compulsion to purchase would be willing to pay. Fair cash value is
determined as of the day prior to the day on which the vote of the appropriate
corporation's shareholders to adopt the merger agreement is taken. When
determining fair cash value, any appreciation or depreciation in market value
resulting from the proposed merger is excluded. In no event can the fair cash
value of a common share exceed the amount specified in the demand of the
particular shareholder discussed in numbered paragraph 3 below.

       To perfect your dissenters' rights, you must satisfy each of the
following conditions:

       1.     You Must be a Shareholder of Park or Security on the Applicable
              Record Date. To be entitled to dissenters' rights, you must be the
              record holder of the dissenting shares on [        ], 2001, if you
              are a Park common shares shareholder, or [        ], 2001, if you
              are a Security


                                       53


<PAGE>   64


              shareholder. If you have a beneficial interest in Park common
              shares or Security common shares held of record in the name of any
              other person for which you desire to perfect dissenters' rights,
              you must cause the shareholder of record to timely and properly
              act to perfect those rights.

       2.     You Must Not Vote in Favor of Adoption of the Merger Agreement.
              Only a shareholder whose Park common shares or Security common
              shares are not voted in favor of adoption of the merger agreement
              is entitled, if the merger is completed, to be paid the fair cash
              value of the Park common shares or Security common shares held of
              record by the shareholder on the applicable record date. If you
              vote for adoption of the merger agreement, your vote will
              constitute a waiver of your dissenters' rights.

       3.     You Must Serve a Written Demand. On or before the tenth day after
              the appropriate corporation's meeting, you must serve a written
              demand for payment of the fair cash value of your common shares to
              Park, if you are a Park shareholder, or to Security, if you are a
              Security shareholder. Your written demand must state your name,
              address, the number of common shares as to which you seek relief
              and the amount claimed by you as the fair cash value of the common
              shares. Voting against adoption of the merger agreement will not
              satisfy the requirement of a written demand for payment.

       4.     You Must Deliver Your Share Certificates for Legending, if
              Requested by Park or Security. If requested by Park or Security,
              you must submit your share certificates for dissenting shares to
              the appropriate corporation within fifteen days after the request
              is sent. That corporation will then endorse the share certificates
              with a legend that demand for fair cash value has been made.

       5.     You Must File a Petition in Court, if You and the Appropriate
              Corporation Cannot Agree on the Fair Cash Value of Your Dissenting
              Shares. If Park or Security and any dissenting shareholder of Park
              or Security, as appropriate, cannot agree on the fair cash value
              of the dissenting shares, either the corporation or the
              shareholder must, within three months after service of the written
              demand by the shareholder, file or join in a petition in the Court
              of Common Pleas of Licking County, Ohio (in the case of Park) or
              Clark County, Ohio (in the case of Security) for a determination
              of the fair cash value of the dissenting shares.

       If you are a shareholder of Park, you must mail or deliver any written
demand for payment to Park National Corporation, 50 North Third Street, Newark,
Ohio 43055, Attention: David C. Bowers, Secretary. If you are a shareholder of
Security, you must mail or deliver any written demand for payment to Security
Banc Corporation, 40 South Limestone Street, Springfield, Ohio 45502, Attention:
J. William Stapleton, Executive Vice President and Secretary. Because you must
deliver the written demand within the ten-day period following the appropriate
corporation's special meeting, we recommend, but do not require, that if you use
the mails, you use certified or registered mail, return receipt requested, to
confirm that you have made a timely delivery.

       If you dissent from the merger, your right to be paid the fair cash value
of your Park common shares or Security common shares will terminate:

       -      if, for any reason, the merger is not completed;

       -      if you fail to serve a timely and appropriate written demand upon
              Park or Security;

       -      if you do not, upon request of Park or Security, make timely and
              appropriate surrender of the share certificates evidencing your
              dissenting shares for endorsement of a legend that you have made a
              demand for the fair cash value of your common shares;

       -      if you withdraw your demand with the consent of the board of
              directors of the corporation whose common shares you hold;


                                       54


<PAGE>   65


       -      if you and the corporation whose common shares you hold do not
              agree upon the fair cash value per share of your common shares and
              you have not timely filed or joined in an appropriate petition in
              the Court of Common Pleas of Licking County, Ohio in the case of
              Park or Clark County, Ohio in the case of Security Banc; or

       -      if you otherwise fail to comply with the requirements of Section
              1701.85 of the Ohio Revised Code.

       A dissenting shareholder of Park or Security who receives payment for
common shares in cash will recognize capital gain or loss, if the common shares
were held as a capital asset at the effective time of the merger, equal to the
difference between the cash received and the holder's basis in the common
shares, provided the payment is not essentially equivalent to a dividend within
the meaning of Section 302 of the Internal Revenue Code. A sale of common shares
pursuant to an exercise of dissenters' rights will not constitute a "dividend"
if, as a result of the exercise, the shareholder owns no common shares in Park
as the surviving corporation in the merger, either actually or constructively
within the meaning of Section 318 of the Internal Revenue Code.

       If you are not in favor of the merger but do not wish to exercise
dissenters' rights, you may, in the alternative, attempt to sell your Park or
Security common shares in the open market at the then current market price.

          UNAUDITED CONDENSED PRO FORMA COMBINED FINANCIAL INFORMATION

       The following tables present unaudited condensed pro forma combined
financial data to show the impact of the merger on Park's financial position.
The pro forma information reflects the pooling-of-interests method of
accounting. Each condensed pro forma combined balance sheet assumes that the
merger was completed on the date of the balance sheet, and the condensed pro
forma combined statements of income assume that the merger was completed at the
beginning of each period reported. In each instance, the exchange ratio was
assumed to be .2844.

       The information in the following tables should be read in conjunction
with the historical financial information that Park and Security have presented
in prior filings with the SEC. The pro forma information does not necessarily
reflect what the historical results of Park would have been had Park and
Security been combined during the periods presented. See "Where You Can Find
More Information" on page [ ] for a description of where you can find the
historical financial information included in prior SEC filings.


                                       55

<PAGE>   66
                   CONDENSED PRO FORMA COMBINED BALANCE SHEET
                              AT SEPTEMBER 30, 2000
                             (DOLLARS IN THOUSANDS)


<TABLE>
<CAPTION>
                                                     PARK         SECURITY
                                                   NATIONAL         BANC                       PRO FORMA
                                                 CORPORATION     CORPORATION    ADJUSTMENTS     COMBINED
                                                --------------- -------------- -------------- -------------
<S>                                            <C>             <C>            <C>            <C>
ASSETS
  Cash and due from banks                       $  101,655      $   28,610     $       -      $  130,265
  Federal funds sold                                     -          16,040             -          16,040
  Interest bearing deposits                              -           1,620             -           1,620
  Securities available-for-sale                    766,867         183,327          (274)        949,920
  Securities held-to-maturity                        4,217          27,893             -          32,110
                                                ----------      ----------     ---------      ----------
    Total investment securities                    771,084         211,220          (274)        982,030
  Loans, net of unearned income                  2,256,146         681,330             -       2,937,476
  Allowance for possible loan losses                48,266           6,462             -          54,728
                                                ----------      ----------     ---------      ----------
  Loans, net                                     2,207,880         674,868             -       2,882,748
  Bank premises and equipment                       30,497           8,680             -          39,177
  Other assets                                     101,068          45,491             -         146,559
                                                ----------      ----------     ----------     ----------
TOTAL ASSETS                                    $3,212,184      $  986,529     $    (274)     $4,198,439
                                                ----------      ----------     ----------     ----------

LIABILITIES
  Deposits                                      $2,368,296      $  724,187     $       -      $3,092,483
  Short-term borrowings                            326,784          29,917             -         356,701
  Long-term borrowings                             181,677         103,499             -         285,176
  Other liabilities                                 27,874           6,374             -          34,248
                                                ----------      ----------     ---------      ----------
TOTAL LIABILITIES                                2,904,631         863,977             -       3,768,608
                                                ----------      ----------     ---------      ----------

SHAREHOLDERS' EQUITY
  Common stock                                  $   76,869      $   19,827     $  22,533      $  119,229
  Surplus                                                -          22,533       (22,533)              -
  Accumulated other comprehensive income, net       (3,713)         (4,734)            -          (8,447)
  Retained earnings                                264,783          98,002             -         362,785
  Treasury stock                                   (30,386)        (13,076)         (274)        (43,736)
TOTAL SHAREHOLDERS' EQUITY                         307,553         122,552          (274)        429,831
                                                ----------      ----------     ----------     ----------

TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY      $3,212,184      $  986,529     $    (274)     $4,198,439
</TABLE>



                                       56
<PAGE>   67

                   CONDENSED PRO FORMA COMBINED BALANCE SHEET
                              AT DECEMBER 31, 1999
                             (DOLLARS IN THOUSANDS)

<TABLE>
<CAPTION>
                                                     PARK         SECURITY
                                                   NATIONAL         BANC                       PRO FORMA
                                                 CORPORATION     CORPORATION    ADJUSTMENTS     COMBINED
                                                --------------- -------------- -------------- -------------
<S>                                            <C>             <C>            <C>            <C>
ASSETS
  Cash and due from banks                       $   123,975     $   50,216     $       -      $  174,191
  Federal funds sold                                  1,550         10,010             -          11,560
  Interest bearing deposits                               -          1,560             -           1,560
  Securities available-for-sale                     778,570        178,614             -         957,184
  Securities held-to-maturity                         4,321         35,689             -          40,010
                                                -----------     ----------     ---------      ----------
    Total investment securities                     782,891        214,303             -         997,194
  Loans, net of unearned income                   2,127,425        653,025             -       2,780,450
  Allowance for possible loan losses                 45,176          6,964             -          52,140
                                                -----------     ----------     ---------      ----------
  Loans, net                                      2,082,249        646,061             -       2,728,310
  Bank premises and equipment                        32,468          9,292             -          41,760
  Other assets                                      110,230         44,969             -         155,199
                                                -----------     ----------     ---------      ----------
TOTAL ASSETS                                    $ 3,133,363     $  976,411     $       -      $4,109,774
                                                -----------     ----------     ---------      ----------

LIABILITIES
  Deposits                                      $ 2,408,062     $  696,546     $       -      $3,104,608
  Short-term borrowings                             364,258         57,731             -      $  421,989
  Long-term borrowings                               16,993         97,652             -         114,645
  Other liabilities                                  53,989          5,360             -          59,349
                                                -----------     ----------     ---------      ----------
TOTAL LIABILITIES                                 2,843,302        857,289             -       3,700,591
                                                -----------     ----------     ---------      ----------

SHAREHOLDERS' EQUITY
  Common stock                                       79,108         19,800        22,302         121,210
  Surplus                                                 -         22,302       (22,302)              0
  Accumulated other comprehensive income, net        (9,161)        (7,143)            -         (16,304)
  Retained earnings                                 243,488         90,084             -         333,572
  Treasury stock                                    (23,374)        (5,921)            -         (29,295)
TOTAL SHAREHOLDERS' EQUITY                          290,061        119,122             -         409,183
                                                -----------     ----------     ---------      ----------

TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY      $ 3,133,363     $  976,411            -       $4,109,774
</TABLE>




                                       57
<PAGE>   68


                CONDENSED PRO FORMA COMBINED STATEMENT OF INCOME
                  FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2000
                  (DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)

<TABLE>
<CAPTION>

                                                       PARK           SECURITY
                                                     NATIONAL           BANC        CONSOLIDATED
                                                   CORPORATION      CORPORATION       PRO FORMA
                                                 --------------------------------------------------
<S>                                               <C>              <C>              <C>
INTEREST INCOME
  Loans, including fees                            $   146,342      $    43,766      $   190,108
  Investment securities                                 37,810           10,035           47,845
  Other                                                    142              905            1,047
                                                   -----------      -----------      -----------
  Total interest income                                184,294           54,706          239,000

INTEREST EXPENSE:
  Deposits                                              62,901           18,129           81,030
  Short-term borrowings                                 10,990            1,650           12,640
  Long-term borrowings                                   7,115            3,659           10,774
                                                   -----------      -----------      -----------
  Total interest expense                                81,006           23,438          104,444

                                                   -----------      -----------      -----------
  Net interest income                                  103,288           31,268          134,556

  Provision for loan losses                              5,850            1,065            6,915

                                                   -----------      -----------      -----------
  Net interest income after provision for loan
    losses                                              97,438           30,203          127,641

NONINTEREST INCOME                                      22,366            6,485           28,851
NONINTEREST EXPENSE                                     60,857           17,428           78,285

                                                   -----------      -----------      -----------
INCOME BEFORE INCOME TAXES                              58,947           19,260           78,207

Income tax expense                                      16,529            6,347           22,876

                                                   -----------      -----------      -----------
NET INCOME                                         $    42,418      $    12,913      $    55,331
                                                   ===========      ===========      ===========

EARNINGS PER SHARE:
  Basic                                            $      3.91      $      1.08      $      3.89
  Diluted                                          $      3.90      $      1.08      $      3.88
  Average common shares - basic                     10,846,778       11,921,658       14,235,876
  Average common shares - diluted                   10,881,216       11,942,516       14,276,246
</TABLE>



                                       58
<PAGE>   69


                CONDENSED PRO FORMA COMBINED STATEMENT OF INCOME
                      FOR THE YEAR ENDED DECEMBER 31, 1999
                  (DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)

<TABLE>
<CAPTION>

                                                       PARK           SECURITY
                                                     NATIONAL           BANC        CONSOLIDATED
                                                   CORPORATION      CORPORATION       PRO FORMA
                                                 --------------------------------------------------
<S>                                              <C>               <C>              <C>
INTEREST INCOME
  Loans, including fees                           $    173,722      $    54,373      $   228,095
  Investment securities                                 50,226           13,268           63,494
  Other                                                    368            1,077            1,445
                                                  ------------      -----------      -----------
  Total interest income                                224,316           68,718          293,034

INTEREST EXPENSE:
  Deposits                                              76,294           21,287           97,581
  Short-term borrowings                                 14,225            1,542           15,767
  Long-term borrowings                                   1,035            4,855            5,890
                                                  ------------      -----------      -----------
  Total interest expense                                91,554           27,684          119,238

                                                  ------------      -----------      -----------
  Net interest income                                  132,762           41,034          173,796

  Provision for loan losses                             11,269            1,200           12,469

                                                  ------------      -----------      -----------
  Net interest income after provision for loan
    losses                                             121,493           39,834          161,327

NONINTEREST INCOME                                      23,564            8,533           32,097
NONINTEREST EXPENSE                                     79,912           23,548          103,460

                                                  ------------      -----------      -----------
INCOME BEFORE INCOME TAXES                              65,145           24,819           89,964

Income tax expense                                      18,358            7,801           26,159

                                                  ------------      -----------      -----------
NET INCOME                                        $     46,787      $    17,018      $    63,805
                                                  ============      ===========      ===========

EARNINGS PER SHARE:
  Basic                                           $       4.30      $      1.40      $      4.45
  Diluted                                         $       4.28      $      1.39      $      4.43
  Average common shares - basic                     10,878,045       12,165,146       14,337,813
  Average common shares - diluted                   10,934,203       12,218,821       14,409,236
</TABLE>




                                       59
<PAGE>   70

                CONDENSED PRO FORMA COMBINED STATEMENT OF INCOME
                      FOR THE YEAR ENDED DECEMBER 31, 1998
                  (DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)

<TABLE>
<CAPTION>

                                                       PARK           SECURITY
                                                     NATIONAL           BANC        CONSOLIDATED
                                                   CORPORATION      CORPORATION       PRO FORMA
                                                 --------------------------------------------------
<S>                                                <C>               <C>             <C>
INTEREST INCOME
  Loans, including fees                            $   169,943      $    53,093      $   223,036
  Investment securities                                 46,537            8,339           54,876
  Other                                                    966            2,602            3,568
                                                   -----------      -----------      -----------
  Total interest income                                217,446           64,034          281,480

INTEREST EXPENSE:
  Deposits                                              82,470           22,468          104,938
  Short-term borrowings                                  9,938            1,727           11,665
  Long-term borrowings                                   1,460                0            1,460
                                                   -----------      -----------      -----------
  Total interest expense                                93,868           24,195          118,063

                                                   -----------      -----------      -----------
  Net interest income                                  123,578           39,839          163,417

  Provision for loan losses                              6,978            1,540            8,518

                                                   -----------      -----------      -----------
  Net interest income after provision for loan
    losses                                             116,600           38,299          154,899

NONINTEREST INCOME                                      26,455            8,489           34,944
NONINTEREST EXPENSE                                     75,323           22,974           98,297

                                                   -----------      -----------      -----------
INCOME BEFORE INCOME TAXES                              67,732           23,814           91,546

Income tax expense                                      20,724            8,194           28,918

                                                   -----------      -----------      -----------
NET INCOME                                         $    47,008      $    15,620      $    62,628
                                                   ===========      ===========      ===========

EARNINGS PER SHARE:
  Basic                                            $      4.31      $      1.29      $      4.36
  Diluted                                          $      4.28      $      1.28      $      4.33
  Average common shares - basic                     10,902,374       12,143,743       14,356,055
  Average common shares - diluted                   10,970,913       12,227,292       14,448,355
</TABLE>



                                       60
<PAGE>   71


                CONDENSED PRO FORMA COMBINED STATEMENT OF INCOME
                      FOR THE YEAR ENDED DECEMBER 31, 1997
                  (DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)

<TABLE>
<CAPTION>
                                                       PARK           SECURITY
                                                     NATIONAL           BANC        CONSOLIDATED
                                                   CORPORATION      CORPORATION       PRO FORMA
                                                 ----------------- --------------- ---------------
<S>                                               <C>              <C>              <C>
INTEREST INCOME
  Loans, including fees                            $   164,315      $    50,168      $   214,483
  Investment securities                                 44,069           10,721           54,790
  Other                                                    833            1,889            2,722
                                                   -----------      -----------      -----------
  Total interest income                                209,217           62,778          271,995

INTEREST EXPENSE:
  Deposits                                              79,195           22,903          102,098
  Short-term borrowings                                  8,422            2,000           10,422
  Long-term borrowings                                   3,162                0            3,162
                                                   -----------      -----------      -----------
  Total interest expense                                90,779           24,903          115,682

                                                   -----------      -----------      -----------
  Net interest income                                  118,438           37,875          156,313

  Provision for loan losses                              7,284            1,300            8,584

                                                   -----------      -----------      -----------
  Net interest income after provision for loan
    losses                                             111,154           36,575          147,729

NONINTEREST INCOME                                      22,535            7,104           29,639
NONINTEREST EXPENSE                                     71,910           22,729           94,639

                                                   -----------      -----------      -----------
INCOME BEFORE INCOME TAXES                              61,779           20,950           82,729

Income tax expense                                      18,738            6,462           25,200

                                                   -----------      -----------      -----------
NET INCOME                                         $    43,041      $    14,488      $    57,529
                                                   ===========      ===========      ===========

EARNINGS PER SHARE:
  Basic                                            $      3.93      $      1.20      $      3.99
  Diluted                                          $      3.91      $      1.19      $      3.97
  Average common shares - basic                     10,964,198       12,117,526       14,410,422
  Average common shares - diluted                   11,021,886       12,194,892       14,490,113
</TABLE>



                                       61
<PAGE>   72

             PARK NATIONAL CORPORATION AND SECURITY BANC CORPORATION
      NOTES TO UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

Note 1 - Basis of Presentation

         On November 21, 2000, Park announced that it had signed a definitive
agreement to acquire Security in a stock-for-stock merger.

         The unaudited pro forma condensed combined financial information has
been prepared assuming that the merger will be accounted for under the
pooling-of-interests accounting method and is based on the historical
consolidated financial statements of the two corporations. A review of each
corporation's respective accounting policies has not been completed. As a result
of this review, it might be necessary to restate certain amounts in the
financial statements of the combined corporation to conform to those accounting
policies that will be followed by the combined corporation. Any restatements of
this nature are not expected to be material.

Note 2 - Shareholders' Equity

         Under the terms of the merger agreement, Park will issue 3,350,000
common shares to the Security shareholders. The exchange ratio is expected to be
 .2844, so that Security shareholders will receive .2844 Park common share for
each common share of Security owned immediately prior to the completion of the
merger. The Park common shares do not have a stated value and as a result, the
surplus account is not used. In combining the financial statements of Park and
Security, the surplus account for Security is moved to common shares.

         Park owns 15,000 Security common shares at a cost of $274,000. These
common shares were purchased on June 2, 2000. In combining the financial
statements of Park and Security, this $274,000 is eliminated by reducing
securities available-for-sale and increasing treasury stock.






                                       62
<PAGE>   73

                                BUSINESS OF PARK

GENERAL

        Park is a bank holding company which is incorporated under Ohio law.
Through its banking subsidiaries, Park National Bank, Richland Trust, Century
National Bank, First-Knox National Bank, United Bank and Second National Bank,
Park is engaged in a general commercial banking and trust business in small to
medium population Ohio communities. Guardian Financial provides consumer finance
services in the central Ohio area. Park's subsidiaries compete for deposits and
loans with other banks, savings associations, credit unions and other types of
financial institutions and operate 77 full-service offices and a network of 80
automatic teller machines in 20 central and southern Ohio counties.

        Park National Bank, Richland Trust, Century National Bank, First-Knox
National Bank, United Bank and Second National Bank provide the following
principal services:

        -   the acceptance of deposits for demand, savings and time accounts and
            the servicing of those accounts;

        -   commercial, industrial, consumer and real estate lending, including
            installment loans and automobile leasing, credit cards and personal
            lines of credit;

        -   safe deposit operations;

        -   trust services;

        -   cash management;

        -   electronic funds transfers; and

        -   a variety of additional banking-related services tailored to the
            needs of individual customers.

        Park National Bank also leases equipment under terms similar to its
commercial lending policies. Park Leasing Company, a division of Park National
Bank, originates and services direct leases of equipment which Park National
Bank acquires with no outside financing. In addition, Scope Leasing, Inc., a
wholly-owned subsidiary of Park National Bank, specializes in aircraft
financing.

        Park is subject to regulation by the Federal Reserve Board. As national
banks, Park National Bank, Century National Bank, First-Knox National Bank,
United Bank and Second National Bank are supervised and regulated by the Office
of the Comptroller of the Currency. As an Ohio state-chartered bank, Richland
Trust is supervised and regulated by the Ohio Division of Financial
Institutions. In addition, as insurer of their deposits, the Federal Deposit
Insurance Corporation has some regulatory authority over Park National Bank,
Richland Trust, Century National Bank, First-Knox National Bank, United Bank and
Second National Bank, including authority to impose assessments for deposit
insurance. As an Ohio consumer finance company, Guardian Financial is supervised
and regulated by the Ohio Division of Financial Institutions.

        Park National Bank, in addition to having seven offices in Newark
(including the main office and the Operations Center) has offices in Granville,
Heath (two offices), Hebron, Johnstown, Kirkersville, Pataskala and Utica in
Licking County, an office in Columbus in Franklin County, an office in
Cincinnati in Hamilton County, an office in Dayton in Montgomery County and
offices in Baltimore, Pickerington and Lancaster (seven offices) in Fairfield
County. The offices in Fairfield County comprise the Fairfield National
Division. Park National Bank also operates nine stand-alone automatic banking
center locations.

        Richland Trust, in addition to six offices in Mansfield (including the
main office), has offices in Butler, Lexington, Ontario and Shelby (two offices)
in Richland County. Richland Trust also operates three stand-alone automatic
banking center locations.

                                       63
<PAGE>   74

        Century National Bank, in addition to having four offices (including the
main office) and a mortgage lending office in Zanesville, has offices in New
Concord and Dresden in Muskingum County, Malta in Morgan County, New Lexington
in Perry County, Logan in Hocking County, Athens in Athens County and Coshocton
in Coshocton County. Century National Bank also operates seven stand-alone
automatic banking center locations.

        First-Knox National Bank, in addition to having three offices (including
the main office and operations center) in Mount Vernon, has offices in
Loudonville and Perrysville in Ashland County, an office in Millersburg in
Holmes County, offices in Centerburg, Danville and Fredericktown in Knox County,
two offices in Mount Gilead in Morrow County and an office in Bellville in
Richland County. The offices in Ashland County comprise the Farmers and Savings
Division. First-Knox National Bank also operates four stand-alone automatic
banking center locations.

        United Bank, in addition to having two offices (including the main
office and operations center) in Bucyrus, has offices in Crestline and Galion in
Crawford County and offices in Waldo, Marion, Caledonia, and Prospect in Marion
County.

        Second National Bank, in addition to having four offices (including the
main office) in Greenville has two offices in Arcanum and an office in
Versailles in Darke County and an office in Fort Recovery in Mercer County.

        Guardian Financial has its main office in Hilliard in Franklin County,
an office in Mansfield where it leases space from Richland Trust, and an office
in Lancaster where it leases space from the Fairfield National Division of Park
National Bank.

ADDITIONAL INFORMATION

        For additional information concerning Park, see "Where You Can Find More
Information" on page [     ].

                               MANAGEMENT OF PARK

BOARD OF DIRECTORS

        The following table gives information, as of [           ], 200[  ],
concerning the individuals who are and will remain the members of the board of
directors of Park, the surviving corporation in the merger. Unless the table
indicates otherwise, each individual has held his or her principal occupation
for more than five years.

<TABLE>
<CAPTION>

                                Position(s) Held with Park                       Director of Park
                                and its Principal Subsidiaries                     Continuously
Name                     Age    and Principal Occupations                             Since          Term Expires In
----                     ---    -------------------------                        ----------------    ---------------

<S>                     <C>     <C>                                                    <C>                <C>
Maureen Buchwald         69     Vice President of Ariel Corporation                    1997               2001
                                (manufacturer of reciprocating compressors)
                                until her retirement in 1997; Director of
                                First-Knox National Bank

James J. Cullers         70     Senior Partner, Zelkowitz, Barry & Cullers,            1997               2003
                                Attorneys at Law, Mount Vernon, Ohio;
                                Director of First-Knox National Bank
</TABLE>

                                       64
<PAGE>   75

<TABLE>
<CAPTION>

                                Position(s) Held with Park                       Director of Park
                                and its Principal Subsidiaries                     Continuously
Name                     Age    and Principal Occupations                             Since          Term Expires In
----                     ---    -------------------------                        -----------------   ---------------

<S>                     <C>     <C>                                                   <C>                <C>
C. Daniel DeLawder       51     Chief Executive Officer since January 1999,            1994               2002
                                and President since 1994, of Park; Chief
                                Executive Officer since January 1999,
                                President since 1993, Executive Vice President
                                from 1992 to 1993, and Director of Park National
                                Bank; Chairman of Advisory Board since 1989 and
                                President from 1985 to 1992 of the Fairfield
                                National Division of Park National Bank;
                                Director of Richland Trust; Director of Second
                                National Bank; Chairman of the Board of
                                Guardian Finance

D. C. Fanello            78     Vice Chairman and founder of Shiloh Corporation,       1990               2001
                                Mansfield, Ohio (stamping/blanking); Director of
                                Richland Trust

R. William Geyer         69     Partner, Kincaid, Taylor and Geyer, Attorneys at       1992               2003
                                Law, Zanesville, Ohio; Director of Century
                                National Bank

Philip H. Jordan, Jr.,   69     Retired.  From 1975 to 1995, President of              1997               2002
Ph.D.                           Kenyon College; Chairman of the Board and
                                Director of First-Knox National Bank

Howard E. LeFevre        93     Chairman of the Board of Freight Service,              1987               2002
                                Inc., Newark, Ohio (leasing and warehousing);
                                Director of Park National Bank

Phillip T. Leitnaker     72     President and owner of Phillip Leitnaker               1990               2001
                                Construction, Inc. Baltimore, Ohio
                                (construction company); Owner of Leitnaker
                                Farms, Baltimore, Ohio (farming); President
                                and majority owner of D & B Paving Company,
                                Baltimore, Ohio (paving company); Member of
                                Advisory Board of Fairfield National Division
                                of Park National Bank
</TABLE>

                                       65
<PAGE>   76

<TABLE>
<CAPTION>

                                Position(s) Held with Park                       Director of Park
                                and its Principal Subsidiaries                     Continuously
Name                     Age    and Principal Occupations                             Since          Term Expires In
----                     ---    -------------------------                         --------------      ---------------

<S>                     <C>     <C>                                                   <C>                <C>
William T. McConnell     67     Chairman of the Board since 1994, Chief                1986               2003
                                Executive Officer from 1986 to January
                                1999, and President from 1986 to 1994, of
                                Park; Chairman of the Board since 1993,
                                Chief Executive Officer from 1983 to January
                                1999, President from 1979 to 1993, and
                                Director of Park National Bank; Director of
                                Century National Bank; Director of First-Knox
                                National Bank

James A. McElroy         68     Chairman of the Board, AMG Industries, Inc.            1997               2003
                                (manufacturer of automobile parts), Mount
                                Vernon, Ohio; Director of First-Knox National
                                Bank

John J. O'Neill          80     President/Owner of Southgate Corporation,              1987               2002
                                Newark, Ohio (real estate development and
                                management); Director of Park National Bank

William A. Phillips      67     Chairman of the Board since 1986, Chief                1990               2003
                                Executive Officer from 1986 to 1998, and
                                Director of Century National Bank

J. Gilbert Reese         75     Senior Partner, Reese, Pyle, Drake & Meyer,            1987               2001
                                P.L.L., Attorneys at Law, Newark, Ohio;
                                Chairman Emeritus of First Federal Savings
                                and Loan Association of Newark, Newark,
                                Ohio; Director of Park National Bank

Rick R. Taylor           53     President of Jay Plastics Corp., Mansfield,            1995               2001
                                Ohio (plastic parts manufacturer); Director
                                of Richland Trust

John L. Warner           73     Agent, Dawson, Coleman & Wallace Insurance             1987               2003
                                Agency, Inc. (successor to W. A. Wallace
                                Co.), Newark, Ohio (insurance);  Director
                                of Park National Bank
</TABLE>

        In addition, Park and Security have agreed that, following the merger,
Harry O. Egger will become a director of Park with a term expiring in 2002. Mr.
Egger is 61 years old and has served as a director of Security since 1977. Mr.
Egger also serves as the Chairman of the Board, President and Chief Executive
Officer of Security and as the Chairman of the Board and Chief Executive Officer
of Security National Bank.

                                       66
<PAGE>   77

EXECUTIVE OFFICERS

        The following table lists the names and ages of the executive officers
of Park as of [    ], 200[ ], the positions presently held by those individuals
and their individual business experience during the past five years. These
individuals will be the executive officers of the surviving corporation in the
merger. The board of directors may remove any of the executive officers at any
time.

<TABLE>
<CAPTION>
                                                    Positions Held with Park and its
Name                              Age        Principal Subsidiaries and Principal Occupation
----                              ---        -----------------------------------------------

<S>                              <C>       <C>
William T. McConnell              67         Chairman of the Board since 1994, Chief Executive
                                             Officer from 1986 to January 1999, President from
                                             1986 to 1994 and Director of Park; Chairman of the
                                             Board since 1993, Chief Executive Officer from
                                             1983 to January 1999, President from 1979 to 1993,
                                             and Director of Park National Bank; Director of
                                             Century National Bank; Director of First-Knox
                                             National Bank

C. Daniel DeLawder                51         Chief Executive Officer since January 1999,
                                             President since 1994 and Director of Park; Chief
                                             Executive Officer since January 1999, President
                                             since 1993, Executive Vice President from 1992
                                             to 1993, and Director of Park National Bank;
                                             Chairman of Advisory Board since 1989 and President
                                             from 1985 to 1992 of the Fairfield National Division
                                             of Park National Bank; Director of Richland Trust;
                                             Director of Second National Bank; Chairman of the
                                             Board of Guardian Financial

David C. Bowers                   63         Secretary since 1987, Chief Financial Officer and
                                             Chief Accounting Officer from 1990 to 1998, and
                                             Director from 1989 to 1990, of Park; Executive Vice
                                             President since January 1999, Senior Vice President
                                             from 1986 to January 1999, and Director of Park
                                             National Bank; Director of Guardian Financial
</TABLE>

        In addition, Park and Security have agreed that Harry O. Egger will
become the Vice Chairman of Park following the merger. Mr. Egger is 61 years
old. He current serves as the Chairman of the Board, President and Chief
Executive Officer of Security and as the Chairman of the Board and Chief
Executive Officer of Security National Bank.

ADDITIONAL INFORMATION

        For additional information concerning the directors and executive
officers of Park, see "Where You Can Find More Information" on page [  ].

                              BUSINESS OF SECURITY

GENERAL

        Security is a bank holding company incorporated under Ohio law. Security
is headquartered in Springfield, Ohio. Security was organized in 1985 under the
laws of the State of Ohio. The subsidiaries of Security are Security National
Bank, Citizens National Bank and Third Savings. Security National Bank is a
national banking association organized under the statutes of the United States
as the result of an agreement to merge The Guardian Bank of Springfield, Ohio,
with and into The New Carlisle National Bank under the title of The Security
National Bank. The agreement to merge was finalized and given approval by the
Office of the Comptroller of the Currency on October 1, 1969. Security National
Bank was granted the authority to act as fiduciary as of May 30, 1978, thereby
changing its name to "The Security National Bank and Trust Co." Security
National Bank is operating under a 1903 charter. On September 30, 1996, Citizens
National Bank became a wholly-owned subsidiary of Security when Security merged
with CitNat Bancorp, Inc., a $140 million one bank holding company headquartered
in Urbana, Ohio, in a transaction accounted for a pooling-of-interests. Citizens
National Bank is a national banking association


                                       67
<PAGE>   78

chartered in 1865. On October 21, 1996, Third Savings became a wholly-owned
subsidiary of Security when Security acquired all of the outstanding shares of
Third Financial Corporation, a $156 million one bank holding company
headquartered in Piqua, Ohio. The acquisition was accounted for using the
purchase method of accounting. Third Savings was chartered in 1884. All of the
banking centers of Security's subsidiaries are located in Champaign, Clark,
Fayette, Greene, Madison, and Miami Counties.

        Security's subsidiaries provide full service banking to individuals as
well as to industry and governmental subdivisions through each of their
twenty-four banking centers. Security's subsidiaries have made a strong impact
on all the counties they serve through a great variety of services, including
personal checking accounts and savings programs, certificates of deposit, money
market accounts, certificates of deposit and individual retirement accounts.

        A broad range of credit programs for all retail customers includes
mortgage loans, credit card banking under the VISA designation, installment
loans, and secured and unsecured personal loans. The banking services provided
to commercial customers and government include maintenance of demand and time
deposit accounts. Available are all types of commercial loans, including loans
under lines of credit and revolving credit, term loans, real estate mortgage
loans and other specialized loans. Security's subsidiaries further serve the
requirements of large and small industrial and commercial enterprises in the
Springfield and Dayton metropolitan area and elsewhere by providing financial
counseling, cash management and other automated services. The subsidiaries'
commercial banking divisions are organized to serve the needs of the corporate
customers by handling business and commercial mortgages, corporate deposits and
other corporate financial services. The consumer banking divisions, which
encompass the credit card and installment loan departments, serve individual as
well as corporate customers. The residential mortgage loan departments provide
conventional as well as adjustable rate mortgage loans to individuals. Each
Security subsidiary manages the investment of funds for that institution using
U.S. government and agency securities, municipal (tax-exempt) securities, as
well as federal funds, and certificates of deposit of U.S. banks and savings and
loans. Each Security subsidiary, in consultation with the other Security
subsidiaries, sets the rates on its liability products. Complete fiduciary
services are available to individuals, charitable institutions, commercial
customers and government agencies through Security National Bank's trust
division. The personal trust department serves as investment agent and custodian
for securities portfolios of individuals, as trustees for living and
testamentary trusts and as executor and administrator of probate estates. The
corporate trust department serves as trustee for corporate and municipal bond
issues, and as registrar for securities. The institutional services department
provides employee benefit plan fund management for qualified retirement plans
and investment management and securities custody services for not-for-profit
institutions.

        There are over a half dozen commercial banks in Springfield, Clark
County and adjoining counties, furnishing general banking services and thus
providing strong competition to Security's subsidiaries. Security's subsidiaries
compete for deposits not only with commercial banks in their area, but also with
savings associations and other non-bank competitors, such as brokerage houses.
In addition to the competition described above, Security's subsidiaries compete
in various areas of service offered to individuals, industry and government with
banks in Southwestern Ohio, many of which possess greater financial resources
than Security.

        The earnings of Security are affected by general economic conditions as
well as the monetary policies of the Federal Reserve Board. Such policies, which
have the effect of regulating the national supply of bank reserves and bank
credit, can have a major affect upon the source and cost of loanable and
investable funds and the rates of return earned on loans and investments. Among
the means available to the monetary authorities to influence the size and
distribution of reserves are open market operations by the Federal Reserve
Board, changes in cash reserve requirements against member bank deposits.

ADDITIONAL INFORMATION

        For additional information concerning Security, see "Where You Can Find
More Information" on page [  ].

                                       68
<PAGE>   79

              COMPARISON OF RIGHTS OF HOLDERS OF PARK COMMON SHARES
                      AND HOLDERS OF SECURITY COMMON SHARES

        As a result of the merger, the holders of Security common shares will
become holders of Park common shares. Following the merger, the Park articles
and regulations will govern the rights of those shareholders. Both Security and
Park are incorporated in Ohio, so the Ohio General Corporation Law will continue
to govern the rights of Security shareholders after the merger.

        Differences exist between the rights of holders of Park common shares
and the rights of holders of Security common shares arising from the
distinctions between the articles and regulations of Park and Security. The
rights, however, of holders of Park common shares and those of holders of
Security common shares are similar in many material respects. The significant
differences are addressed below.

AUTHORIZED CAPITAL STOCK

        Park's authorized capital stock consists of 20,000,000 common shares,
without par value, and, as of December 15, 2000, 10,783,682 of these common
shares were outstanding. As of December 15, 2000, an additional 302,480 Park
common shares were subject to outstanding stock options and 327,506 Park common
shares were available for future grants of stock options. Park common shares are
listed on the American Stock Exchange under the symbol "PRK".

        Security's authorized capital stock consists of 18,000,000 common
shares, $1.5625 par value per share, and, as of [              ], 200[ ],
[11,777,700] of these common shares were outstanding. As of [         ], 200[ ],
an additional [174,999] Security common shares were subject to outstanding stock
options. Security common shares are listed on the over-the-counter market under
the symbol "STYB".

COMPOSITION OF BOARD OF DIRECTORS

        The Park regulations provide for a board of directors consisting of not
more than 16 and not less than five directors. Park currently has 15 directors.
Under the Park regulations, there are two ways to change the number of
directors. The number of directors can be changed by the affirmative vote of the
holders of a majority of the shares represented in person or by proxy at any
shareholder meeting to change the number of directors or by a majority of the
Park directors then in office. In the case of a change approved by the
directors, the directors may not increase the number of directors to a number
which exceeds by more than two the number of directors last elected by the
shareholders and cannot exceed 16.

        The Security regulations provide for a board of directors consisting of
16 directors. Security currently has 11 directors. The Security articles and
regulations do not address how the number of directors may be changed. As a
result, Ohio statutory law governs the changing of the number of directors.
Under Section 1701.58 of the Ohio Revised Code, the shareholders may change the
size of the board of directors by a resolution approved by the affirmative vote
of the holders of a majority of shares represented at any meeting called for the
purpose of electing directors.

CLASSIFICATION

        The regulations of both Park and Security divide each corporation's
board of directors into three classes with staggered terms whereby one class is
elected each year for a three-year term. Classification of directors makes it
more difficult for shareholders to change the composition of the board of
directors. Generally, two annual meetings, instead of one, are required to
change the composition of more than one-half of the board of directors. Should a
shareholder attempt to force a proxy contest, a tender or exchange offer or
other extraordinary corporate transaction, this classification and extra time
period would allow the board sufficient time to review the proposal as well as
any available alternatives in order to act in what it believes to be the best
interests of the corporation and its shareholders. The classification
provisions, however, also may discourage a third party from starting a proxy
contest, making a tender offer or otherwise attempting to gain control of the
corporation. As a result, the


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<PAGE>   80

corporation may miss an opportunity to enter into a transaction that could be
beneficial to the corporation and its shareholders.

NOMINATIONS

        The Park regulations provide that shareholder nominations for election
to the Park board of directors must be made in writing and must be delivered or
mailed to the President of Park not less than 14 days nor more than 50 days
prior to any meeting of shareholders called for the election of directors.
However, if Park gives less than 21 days' notice of the meeting to its
shareholders, the nomination must be mailed or delivered to the President of
Park not later than the close of business on the seventh day following the day
on which Park mailed the notice of the meeting. The notification must include
the following information to the extent known by the notifying shareholder:

        -   the name and address of each proposed nominee;

        -   the principal occupation of each proposed nominee;

        -   the total number of Park common shares that will be voted for each
            proposed nominee;

        -   the name and residence address of the notifying shareholder; and

        -   the number of Park common shares beneficially owned by the notifying
            shareholder.

        Nominations which the chairman of the meeting determines are not made in
accordance with the Park regulations may be disregarded.

        The Security articles and regulations do not contain any similar
nomination procedures.

REMOVAL

        The holders of a majority of the voting power of Park entitled to elect
directors may remove a director with or without cause. Unless all directors (or
all directors of a particular class) are removed, however, no individual
director may be removed if the votes of a sufficient number of shares are cast
against the director's removal that, if cumulatively voted at an election of all
of the directors (or all of the directors of a particular class), would be
sufficient to elect at least one director.

        The Security articles and regulations do not include provisions limiting
the removal of directors. As a result, Ohio statutory law governs the removal of
a director from the board of Security. Under Section 1701.58 of the Ohio Revised
Code, the shareholders may remove any director from office, with or without
cause, by the affirmative vote of the holders of a majority of the voting power
entitled to elect directors. Unless all directors are removed (or all directors
of a particular class), however, no individual director may be removed if the
votes of a sufficient number of shares are cast against the director's removal
that, if cumulatively voted at an election of all of the directors (or all
directors of a particular class), would be sufficient to elect at least one
director.

MANDATORY RETIREMENT

        The Security regulations provide that directors of Security will become
ineligible for reelection upon reaching the age of 70. There is no similar
mandatory retirement age for directors of Park.

CUMULATIVE VOTING

        The holders of Park common shares have the right to cumulate votes in
the election of directors. With cumulative voting, it is possible for the
holders of a minority of the common shares to elect one or more directors to the
board of directors, even though the holders of a majority of the common shares
oppose the election of the director(s). The absence of cumulative voting
eliminates the ability of a minority of the shareholders of a


                                       70
<PAGE>   81

corporation to elect one or more directors to that corporation's board of
directors and allows the holders of a majority of the shares of that corporation
to elect each of the directors.

        Security's articles specifically eliminate the right of Security
shareholders to exercise cumulative voting rights in the election of directors.

SPECIAL VOTING REQUIREMENTS

        The Park articles contain special voting requirements that may be deemed
to have anti-takeover effects. These voting requirements are described in
Article Eighth and apply when any of the following actions are contemplated:

        -   any merger or consolidation of Park with a beneficial owner of 20%
            or more of the voting power of Park or an affiliate or associate of
            that 20% beneficial owner;

        -   any sale, lease, exchange, mortgage, pledge, transfer or other
            disposition of at least 10% of the total assets of Park to or with a
            20% beneficial owner or its affiliates or associates;

        -   any merger of Park or one of its subsidiaries with a 20% beneficial
            owner or its affiliates or associates;

        -   any sale, lease, exchange, mortgage, pledge, transfer or other
            disposition to Park or one of its subsidiaries of all or any part of
            the assets of a 20% beneficial owner (or its affiliates or
            associates), excluding any disposition which, if included with all
            other dispositions consummated during the fiscal year by the 20%
            beneficial owner or its affiliates or associates, would not result
            in dispositions having an aggregate fair value in excess of 1% of
            the total consolidated assets of Park, unless all such dispositions
            by the 20% beneficial owner or its affiliates or associates during
            the same and four preceding fiscal years would result in disposition
            of assets having an aggregate fair value in excess of 2% of the
            total consolidated assets of Park;

        -   any reclassification of Park common shares or any recapitalization
            involving the common shares of Park consummated within five years
            after a 20% beneficial owner becomes such;

        -   any agreement providing for any of the previously described business
            combinations; and

        -   any amendment to Article Eighth of the Park articles.

        The enlarged majority vote required when Article Eighth applies is the
greater of:

        -   four-fifths of the outstanding Park common shares entitled to vote
            on the proposed business combination, or

        -   that fraction of the outstanding Park common shares having:

            -   as the numerator a number equal to the sum of:

                -   the number of Park common shares beneficially owned by the
                    20% beneficial owner plus

                -   two-thirds of the remaining number of Park common shares
                    outstanding,

            -   and as the denominator, a number equal to the total number of
                outstanding Park common shares entitled to vote.

        Article Eighth does not apply where (1) the shareholders who do not vote
in favor of the transaction and whose proprietary interest will be terminated in
connection with a transaction are paid a "minimum price per share"


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<PAGE>   82

and (2) a proxy statement satisfying the requirements of the Securities Exchange
Act of 1934 is mailed to the Park shareholders for the purpose of soliciting
shareholder approval of the transaction. If the price criteria and procedural
requirements are satisfied, the approval of a business combination would require
only that affirmative vote (if any) required by law or by the Park articles or
regulations.

        The Security articles also contain special voting requirements. The
Security articles state that any merger, consolidation or acquisition of
Security by another corporation without the approval of Security's board of
directors requires the affirmative approval of 80% of the outstanding Security
common shares and 80% of the outstanding preferred shares or any other class of
shares of Security outstanding at that time.

AMENDMENTS OF ARTICLES

        Under Ohio corporate law, the vote of holders of shares entitling them
to exercise at least two-thirds of the voting power of the corporation is
required to adopt an amendment to the articles of the corporation, unless the
articles provide for a different proportion which cannot be less than a
majority. As discussed above under "Special Voting Rights," Park's articles
require that any amendment to Article Eighth of the articles be adopted by a
different proportion of Park's shareholders. Security's articles do not alter
the two-thirds voting requirement for amending its articles.

AMENDMENTS TO THE REGULATIONS

        The Park regulations may be amended by the affirmative vote of
two-thirds of the voting power of Park at a meeting held for that purpose or
without a meeting by the written consent of two-thirds of the voting power of
Park. The Security regulations may be amended by the affirmative vote of a
majority of the voting power of Security at a meeting held for that purpose or
without a meeting by the written consent of two-thirds of the voting power of
Security.

CALLING A SPECIAL MEETING

        Under the Park regulations, special meetings of shareholders may be
called by the Chairman of the Board, the President, or, in case of the
President's absence, death, or disability, the Vice President authorized to
exercise the authority of the President, the Secretary, the board of directors
at a meeting or acting without a meeting by a majority of the board of directors
or the holders of at least 25% of the voting power of Park.

        Under the Security regulations, special meetings of the shareholders may
be called by the Chairman of the Board, the President, or in case of the
President's absence, death or disability, the Vice President authorized to
exercise the authority of the President, a majority of the directors then in
office acting with or without a meeting, and by three or more shareholders
holding of record 25% or more of the stock of Security.

PREEMPTIVE RIGHTS

        The shareholders of Park have preemptive rights under specified
circumstances. A preemptive right allows a shareholder to maintain a
proportionate share of ownership by purchasing shares of any new share issuance.
The purpose of the right is to protect shareholders from dilution of value and
control when new shares are issued.

        On the offering or sale of any shares of Park, on reasonable terms fixed
by the Park board of directors, shareholders of the same class of shares have
the right to purchase additional shares in proportion to their respective share
holdings at the price fixed for the sale of the shares. This right does not
exist where:

        -   the shares offered or sold are treasury shares;

        -   the shares offered or sold are issued as a share dividend or
            distribution;

        -   the shares are offered or sold in connection with any merger or
            consolidation to which Park is a party or any acquisition of, or
            investment in, another business entity or its assets by Park;

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<PAGE>   83

        -   the shares are offered or sold under the terms of a stock option
            plan or employee benefit, compensation or incentive plan which has
            been approved by the holders of three-fourths of the issued and
            outstanding shares of Park; or

        -   the shares offered or sold are released from preemptive rights by
            the affirmative vote or written consent of the holders of two-thirds
            of the shares entitled to preemptive rights.

        Neither the Security articles nor regulations alter the rights of
Security shareholders with respect to preemptive rights that are provided under
the Ohio General Corporation Law.

DIVIDENDS

        As Ohio corporations, Security and Park may, in the discretion of their
respective boards of directors, generally pay dividends to their shareholders
out of surplus, however created, but must notify the shareholders if a dividend
is paid out of capital surplus.

        The ability of Park and Security to obtain funds for the payment of
dividends and for other cash requirements largely depends on the amount of
dividends which may be declared by their subsidiaries. In addition, the Federal
Reserve Board expects each of Park and Security to serve as a source of strength
to its subsidiary banks, which may require it to retain capital for further
investments in its subsidiary banks, rather than for dividends for its
shareholders.

ANTI-TAKEOVER STATUTES

OHIO CONTROL SHARE ACQUISITION ACT

        Section 1701.831 of the Ohio Revised Code or the "Ohio Control Share
Acquisition Act" provides that notice and informational filings and special
shareholder meetings and voting procedures must occur prior to consummation of a
proposed "control share acquisition," which is defined as any acquisition of
shares of an "issuing public corporation" that would entitle the acquirer,
directly or indirectly, alone or with others, to exercise or direct the voting
power of the issuing public corporation in the election of directors within any
of the following ranges:

        -   one-fifth or more but less than one-third of the voting power;

        -   one-third or more but less than a majority of the voting power; or

        -   a majority or more of the voting power.

        An "issuing public corporation" is an Ohio corporation with fifty or
more shareholders that has its principal place of business, principal executive
offices, or substantial assets within the State of Ohio, and as to which no
valid close corporation agreement exists. Assuming compliance with the notice
and informational filing requirements prescribed by the Ohio Control Share
Acquisition Act, the proposed control share acquisition may take place only if,
at a duly convened special meeting of shareholders at which at least a majority
of the voting power is represented in person or by proxy, the acquisition is
approved by both:

        -   a majority of the voting power of the corporation represented in
            person or by proxy at the meeting, and

        -   a majority of the voting power at the meeting exercised by
            shareholders, excluding:

            -   the acquiring shareholder,

            -   officers of the corporation elected or appointed by the
                directors of the corporation,

            -   employees of the corporation who are also directors of the
                corporation, and

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<PAGE>   84

            -   persons who acquire specified amounts of shares after the first
                public disclosure of the proposed control share acquisition.

        The Ohio Control Share Acquisition Act does not apply to a corporation
whose articles or regulations so provide. The Ohio Control Share Acquisition Act
applies to Security since it has not taken any corporate action to opt out of
it. Park has opted out of the application of the Ohio Control Share Acquisition
Act in its regulations.

OHIO MERGER MORATORIUM STATUTE

        Chapter 1704 of the Ohio Revised Code or the "Ohio Merger Moratorium
Statute" prohibits certain business combinations and transactions between an
"issuing public corporation" and a beneficial owner of shares representing 10%
or more of the voting power of the corporation in the election of directors (an
"interested shareholder") for at least three years after the interested
shareholder becomes such, unless the board of directors of the issuing public
corporation approves either (1) the transaction or (2) the acquisition of the
corporation's shares that resulted in the person becoming an interested
shareholder, in each case before the interested shareholder became such.

        For three years after a person becomes an interested shareholder, the
following transactions between the corporation and the interested shareholder or
persons related to such shareholder are prohibited:

        -   the sale or acquisition of an interest in assets meeting thresholds
            specified in the statute,

        -   mergers and similar transactions,

        -   a voluntary dissolution,

        -   the issuance or transfer of shares or any rights to acquire shares
            having a fair market value at least equal to 5% of the aggregate
            fair market value of the corporation's outstanding shares,

        -   a transaction that increases the interested shareholder's
            proportionate ownership of the corporation, and

        -   any other benefit that is not shared proportionately by all
            shareholders.

        After the three-year period, transactions between the corporation and
the interested shareholder are permitted if:

        -   the transaction is approved by the holders of shares with at least
            two-thirds of the voting power of the corporation in the election of
            directors (or a different proportion specified in the corporation's
            articles), including at least a majority of the outstanding shares
            after excluding shares controlled by the interested shareholder, or

        -   the business combination results in shareholders, other than the
            interested shareholder, receiving a "fair market value" for their
            shares determined by the method described in the statute.

        A corporation may elect not to be covered by the Ohio Merger Moratorium
Statute by the adoption of an appropriate amendment to its articles. The Ohio
Merger Moratorium Statute applies to Security since it has not taken any
corporate action to opt out of it. Park has opted out of the Ohio Merger
Moratorium Statute in its articles.

DIRECTOR AND OFFICER LIABILITY AND INDEMNIFICATION

        The regulations of Park provide that Park will indemnify its directors
or officers against expenses (including attorney's fees, filing fees, court
reporter's fees and transcript costs) judgments, fines and amounts paid in
settlement by reason of the fact that they are or were directors, officers,
employees or agents of Park or, at the request of Park, were serving another
entity in a similar capacity. In order to receive indemnification, the directors


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<PAGE>   85

or officers must have acted in good faith and in a manner they reasonably
believed to be in the best interests of Park. With regard to criminal matters,
Park will indemnify directors and officers if the directors or officers had no
reasonable cause to believe their conduct was unlawful. Directors or officers
claiming indemnification will be presumed to have acted in good faith and in a
manner they reasonably believed to be not opposed to the best interests of Park
and, with respect to any criminal matter, to have had no reasonable cause to
believe their conduct was unlawful.

        Park will not indemnify any officer or director of Park who was a party
to any completed action or suit instituted by, or in the right of, Park for any
matter asserted in the action as to which the officer or director has been
adjudged to be liable for acting with reckless disregard for the best interests
of Park or misconduct, other than negligence, in the performance of the
individual's duty to Park. If, however, the Court of Common Pleas of Licking
County, Ohio or the court in which the action was brought determines that the
officer or director is fairly and reasonably entitled to indemnity, Park must
indemnify the officer or director to the extent permitted by the court.

        Park will make any indemnification not precluded by Park's regulations
only upon a determination that the director or officer has met the applicable
standard of conduct. The determination may be made only:

        -   by a majority vote of a quorum of disinterested directors;

        -   if a quorum is not obtainable or if a majority of a quorum of
            disinterested directors so directs, in a written opinion by
            independent legal counsel;

        -   by the shareholders; or

        -   by the Court of Common Pleas of Licking County, Ohio or the court,
            if any, in which the action was brought.

        Park will pay expenses incurred in defending any action, suit or
proceeding in advance upon receipt of an undertaking by or on behalf of the
director or officer to repay that amount if the director or officer is not
entitled to be indemnified by Park.

        The regulations of Park state that the indemnification provided by the
regulations is not exclusive of any other rights to which any individual seeking
indemnification may be entitled. Additionally, the Park regulations provide that
Park may purchase and maintain insurance on behalf of any individual who is or
was a director, officer, employee or agent of Park, or who is or was serving
another entity at the request of Park, against any liability asserted against
the individual and incurred by the individual in that capacity, or arising out
of the individual's status as such, whether or not Park National would have the
obligation or power to indemnify the individual under the Park regulations. Park
has purchased and maintains those policies.

        The articles of Security provide that Security will indemnify, to the
full extent permitted by Ohio law, its present and past directors, officers,
employees, agents and other persons it has the power to indemnify under Ohio
law. The Security articles further state that Security may, upon the affirmative
vote of a majority of its directors, purchase insurance for the purpose of
indemnifying its directors, officers, employees and agents to the extent
indemnification of these persons is permitted by Ohio law. Security has
purchased and maintains such policies.

        Park also has agreed to indemnify the present officers, directors and
employees of Security and its subsidiaries to the full extent required under
Ohio law and the governing documents of Security and Security's subsidiaries. In
addition, for a three-year period from the date of the merger, Park will
maintain directors' and officers' liability insurance policies covering the
officers and directors of Security and Security's subsidiaries so long as the
cost does not exceed 200% of the current premiums paid by Security for its
directors' and officers' liability insurance policies. For more information, see
"The Merger Agreement - Costs and Expenses; Indemnification" on page [ ].

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<PAGE>   86

                                  LEGAL MATTERS

        The federal income tax consequences of the merger, along with other
legal matters in connection with the merger and the issuance of Park common
shares to former Security shareholders, will be passed upon for Park by Vorys,
Sater, Seymour and Pease LLP.

                                     EXPERTS

PARK

        The consolidated financial statements of Park as of December 31, 1999
and 1998, and for each of the three years in the period ended December 31, 1999,
incorporated by reference in this joint proxy statement/prospectus from Park's
Annual Report on Form 10-K for the fiscal year ended December 31, 1999, have
been audited by Ernst & Young LLP, independent auditors, as set forth in their
report thereon, incorporated by reference herein. Those consolidated financial
statements are incorporated by reference in this joint proxy
statement/prospectus in reliance upon such report given on the authority of such
firm as experts in accounting and auditing.

        The supplemental consolidated financial statements of Park as of
December 31, 1999 and 1998, and for each of the three years in the period ended
December 31, 1999, incorporated by reference in this joint proxy
statement/prospectus from Park's Current Report on Form 8-K dated December 21,
2000, have been audited by Ernst & Young LLP, independent auditors, as set forth
in their report thereon, incorporated by reference herein. Generally accepted
accounting principles proscribe giving effect to a consummated business
combination accounted for by the pooling-of-interests method in financial
statements that do not include the date of consummation. The supplemental
consolidated financial statements do not extend through the date of
consummation; however, they will become the historical consolidated financial
statements of Park after financial statements covering the date of consummation
of the business combinations are issued. The supplemental consolidated financial
statements referred to above are incorporated by reference in this joint proxy
statement/prospectus in reliance upon such report given on the authority of such
firm as experts in accounting and auditing.

SECURITY

        The consolidated financial statements of Security as of December 31,
1999 and 1998, and for each of the three years in the period ended December 31,
1999, incorporated by reference in this joint proxy statement/prospectus from
Security's Annual Report on Form 10-K for the fiscal year ended December 31,
1999, have been audited by Ernst & Young LLP, independent auditors, as set forth
in their report thereon, incorporated by reference herein. Those consolidated
financial statements are incorporated by reference in this joint proxy
statement/prospectus in reliance upon such report given on the authority of such
firm as experts in accounting and auditing.

           CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION

        This document contains forward-looking statements about the merger and
about Park's and Security's respective financial condition, results of
operations, plans, objectives, future performance and business. This includes
information relating to:

        -   benefits, revenues and earnings estimated to result from the merger;
            and

        -   estimated costs of combining Park and Security.

        It also includes statements using words like "believes," "expects,"
"intends," "anticipates" or "estimates" or similar expressions.

        These forward-looking statements involve risks and uncertainties. Actual
results may differ materially from those predicted by the forward-looking
statements because of various factors and possible events, including those
discussed under "Risk Factors" above and the following:

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<PAGE>   87

        -   income, interest and non-interest, following the merger is lower
            than expected;

        -   the costs of providing compensation and benefits to Park's employees
            increase;

        -   competition increases in the banking industry or Park's markets;

        -   costs or difficulties related to the integration of Security's
            business or other acquired businesses are greater than expected;

        -   there are adverse changes in general economic conditions or in
            competitive forces;

        -   technological changes are more difficult or expensive to implement
            than anticipated;

        -   there are adverse changes in the securities markets; and

        -   Park suffers the loss of key personnel.

        There is also the risk that Park incorrectly analyzes these risks and
forces, or that the strategies Park develops to address them are unsuccessful.

        Because these forward-looking statements involve risks and
uncertainties, actual results may differ significantly from those predicted in
these forward-looking statements. You should not place a lot of weight on these
statements. These statements speak only as of the date of this document or, in
the case of any document incorporated by reference, the date of that document.

        All subsequent written and oral forward-looking statements attributable
to Park or Security or any person acting on behalf of Park or Security are
qualified by the cautionary statements in this section. Park and Security have
no obligation to revise these forward-looking statements.

                       WHERE YOU CAN FIND MORE INFORMATION

SEC FILINGS

        Park and Security file annual, quarterly and current reports, proxy
statements and other information with the SEC. These SEC filings are available
to the public at the Internet site maintained by the SEC at http://www.sec.gov.
You can also read and copy any document filed by Park or Security with the SEC
at the SEC's public reference rooms located at:

<TABLE>
<S>                               <C>                               <C>
        450 Fifth Street, N.W.      New York Regional Office         Chicago Regional Office
        Room 1024                   7 World Trade Center             Citicorp Center
        Washington, D.C.  20549     Suite 1300                       500 West Madison Street
                                    New York, New York  10048        Suite 1400
                                                                     Chicago, Illinois  60661
</TABLE>


Please call the SEC at 1-800-SEC-0330 for further information on the public
reference rooms. You may also obtain copies of these SEC filings by mail from
the Public Reference Section of the SEC, 450 Fifth Street, N.W., Room 1024,
Washington, D.C. 20549, at prescribed rates.

        SEC filings are also available from commercial document retrieval
services. Park's SEC filings can also be obtained from the Internet site
maintained by Park at www.parknationalcorp.com and the American Stock Exchange.
For information on obtaining copies of Park's SEC filings at the American Stock
Exchange, call 1-212-306-1000.

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<PAGE>   88

REGISTRATION STATEMENT

        Park has filed with the SEC a registration statement on Form S-4 to
register the Park common shares to be issued to Security shareholders in the
merger. The registration statement, including the attached exhibits and
schedules, contains additional relevant information about Park and Security.
This joint proxy statement/prospectus is part of that registration statement.
The rules and regulations of the SEC allow us to omit some information included
in the registration statement from this document.

DOCUMENTS INCORPORATED BY REFERENCE

        The SEC allows Park and Security to "incorporate by reference"
information into this joint proxy statement/prospectus. This means that Park and
Security can disclose important information to you by referring you to another
document included as an appendix to this joint proxy statement/prospectus or to
documents filed separately with the SEC. The information incorporated by
reference is considered to be a part of this joint proxy statement/prospectus,
except for any information that is superseded by information that is included
directly in this joint proxy statement/prospectus.

PARK DOCUMENTS

        This joint proxy statement/prospectus incorporates by reference the
documents filed by Park with the SEC described below. All of these documents
were or will be filed under SEC File No. 1-13006.

        -   Current Report on Form 8-K filed on December 21, 2000 which includes
            the supplemental financial statements for 1999, 1998 and 1997 which
            give retroactive effect for the acquisitions of SNB Corp. and U.B.
            Bancshares, Inc.;

        -   Annual Report on Form 10-K for the fiscal year ended December 31,
            1999;

        -   Quarterly Reports on Form 10-Q for the fiscal quarters ended March
            31, 2000, June 30, 2000 and September 30, 2000;

        -   Current Reports on Form 8-K dated February 29, 2000, March 15, 2000
            and April 18, 2000;

        -   The description of the Park common shares contained in the Current
            Report on Form 8-K filed on April 21, 1998, including any amendment
            or report filed to update that description; and

        -   All reports and definitive proxy or information statements of Park
            filed pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange
            Act after the date of this joint proxy statement/prospectus and
            before completion of the merger and the exchange of Park common
            shares for Security common shares.

SECURITY DOCUMENTS

        This joint proxy statement/prospectus incorporates by reference the
documents filed by Security with the SEC described below. All of these documents
were or will be filed under SEC File No. 0-13655.

        -   Annual Report on Form 10-K for the fiscal year ended December 31,
            2000 and Amendment No. 1 thereto dated June 7, 2000;

        -   Quarterly Reports on Form 10-Q for the fiscal quarters ended March
            31, 2000, June 30, 2000 and September 30, 2000;

        -   The description of Security's common shares contained in Security's
            Registration Statement on Form S-4 (Amendment No. 1) (Registration
            No. 333-07611) filed on July 16, 1996, including any amendment or
            report filed to update that description; and

                                       78

<PAGE>   89

        -   All reports and definitive proxy or information statements of
            Security filed pursuant to Sections 13(a), 13(c), 14 or 15(d) of the
            Exchange Act after the date of this joint proxy statement/prospectus
            and before completion of the merger and the exchange of Park common
            shares for Security common shares.

        You can obtain copies of any of the documents incorporated by reference
in this joint proxy statement/prospectus through Park or Security, as the case
may be, or from the SEC through the SEC's Internet site at the address described
above. Documents incorporated by reference are available from the corporations,
without charge, excluding exhibits other than those that are specifically
incorporated by reference in this joint proxy statement/prospectus. You may
obtain a copy of any documents incorporated by reference by requesting them in
writing or by telephone from the appropriate corporation at the following
addresses:

<TABLE>
<S>                                             <C>
        Park National Corporation                  Security Banc Corporation
        50 North Third Street                      40 South Limestone Street
        P.O. Box 3500                              Springfield, Ohio 45502
        Newark, Ohio  43058-3500                   Attention:  J. William Stapleton, Executive
        Attention:  David C. Bowers, Secretary                 Vice President and Secretary
        (740) 349-3708                             (937) 324-6916
</TABLE>

        PLEASE REQUEST DOCUMENTS BY [          ], 2001, TO ASSURE THAT YOU WILL
RECEIVE THEM BEFORE THE SPECIAL MEETINGS. If you request any incorporated
documents, Park or Security, as appropriate, will mail them to you by first
class mail, or another equally prompt means, within one business day after
receiving your request.

        Park and Security have not authorized anyone to give any information or
make any representation about the merger or our corporations that differs from,
or adds to, the information in this joint proxy statement/prospectus or in the
reports that are publicly filed with the SEC. Therefore, if anyone does give you
different or additional information, you should not rely on it.

        This joint proxy statement/prospectus is dated [           ], 2001. The
information contained in this joint proxy statement/prospectus speaks only as of
that date, unless the information specifically indicates that another date
applies. You should not assume that the information contained in this joint
proxy statement/prospectus is accurate as of any date other than that date, and
neither the mailing of this joint proxy statement/prospectus to you nor the
issuance to you of Park common shares will create any implication to the
contrary.



                                       79
<PAGE>   90


                                                                      APPENDIX A


                          AGREEMENT AND PLAN OF MERGER,
                         DATED AS OF NOVEMBER 20, 2000,
                        BETWEEN PARK NATIONAL CORPORATION
                          AND SECURITY BANC CORPORATION



                                      A-1
<PAGE>   91




                                TABLE OF CONTENTS

                                                                            PAGE

ARTICLE ONE -- THE MERGER....................................................2

   1.01.      Merger; Surviving Corporation..................................2
   1.02.      Effective Time.................................................2
   1.03.      Effects of the Merger..........................................2

ARTICLE TWO -- CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES................3

   2.01.      Conversion of Security Shares..................................3
   2.02.      Exchange of Certificates.......................................4
   2.03.      Park Shares....................................................9

ARTICLE THREE -- REPRESENTATIONS AND WARRANTIES OF SECURITY..................9

   3.01.      Representations and Warranties of Security.....................9

ARTICLE FOUR -- REPRESENTATIONS AND WARRANTIES OF PARK......................30

   4.01.      Representations and Warranties of Park........................30

ARTICLE FIVE -- FURTHER COVENANTS OF SECURITY...............................34

   5.01.      Operation of Business.........................................34
   5.02.      Notification..................................................39
   5.03.      Shareholder Approval..........................................39
   5.04.      Acquisition Proposals.........................................40
   5.05.      Delivery of Information.......................................40
   5.06.      Affiliates Compliance with the Securities Act.................40
   5.07.      Takeover Laws.................................................41
   5.08.      Title Insurance...............................................41
   5.09.      Schedule 13D and 13G Filings..................................42
   5.10.      Survey........................................................42

ARTICLE SIX -- FURTHER COVENANTS OF PARK....................................42

   6.01.      Access to Information.........................................42
   6.02.      Opportunity of Employment; Employee Benefits..................43
   6.03.      AMEX Listing..................................................43
   6.04.      Takeover Laws.................................................44
   6.05.      Notification..................................................44
   6.06.      Shareholder Approval..........................................44
   6.07.      Officers' and Directors' Indemnification......................44
   6.08.      Governance....................................................46




                                      -i-
<PAGE>   92

   6.09.      Park Acquisition Proposal.....................................46

ARTICLE SEVEN -- FURTHER OBLIGATIONS OF THE PARTIES.........................46

   7.01.      Security Stock Options........................................46
   7.02.      Necessary Further Action......................................47
   7.03.      Cooperative Action............................................47
   7.04.      Satisfaction of Conditions....................................47
   7.05.      Accounting and Tax Treatment..................................47
   7.06.      Confidentiality...............................................48
   7.07.      Press Releases................................................48
   7.08.      Registration Statement........................................48
   7.09.      Regulatory Applications.......................................49
   7.10.      Dividends.....................................................50
   7.11.      Supplemental Assurances.......................................50
   7.12.      Security Split Dollar Plan....................................50
   7.13.      Security Pension Plan.........................................51

ARTICLE EIGHT -- CONDITIONS PRECEDENT TO THE OBLIGATIONS OF THE PARTIES.....51

   8.01.      Conditions to the Obligations of Park.........................51
   8.02.      Conditions to the Obligations of Security.....................54
   8.03.      Mutual Conditions.............................................55

ARTICLE NINE -- CLOSING.....................................................56

   9.01.      Closing.......................................................56
   9.02.      Closing Transactions Required of Park.........................57
   9.03.      Closing Transactions Required of Security.....................57

ARTICLE TEN -- NON-SURVIVAL OF REPRESENTATIONS, WARRANTIES AND COVENANTS....58

   10.01.     Non-Survival of Representations, Warranties and Covenants.....58

ARTICLE ELEVEN -- TERMINATION...............................................58

   11.01.     Termination...................................................58
   11.02.     Effect of Termination.........................................61

ARTICLE TWELVE -- MISCELLANEOUS.............................................63

   12.01.     Notices.......................................................63
   12.02.     Counterparts..................................................64
   12.03.     Entire Agreement..............................................64
   12.04.     Successors and Assigns........................................64
   12.05.     Captions......................................................64


                                       -ii-
<PAGE>   93


   12.06.     Governing Law.................................................64
   12.07.     Payment of Fees and Expenses..................................64
   12.08.     Amendment.....................................................65
   12.09.     Waiver........................................................65
   12.10.     Disclosure Schedules..........................................65
   12.11.     No Third-Party Rights.........................................65
   12.12.     Waiver of Jury Trial..........................................65
   12.13.     Severability..................................................65

















                                      -iii-
<PAGE>   94


                            GLOSSARY OF DEFINED TERMS

         The following terms, when used in this Agreement, have the meanings
ascribed to them in the corresponding Sections of this Agreement listed below:

"Agreement"                                       --       Preamble
"AMEX"                                            --       Section 2.02(e)
"Acquisition Proposal"                            --       Section 5.04
"Average Closing Price of Park Shares"            --       Section 2.02(e)
"BHC Act"                                         --       Section 3.01(a)
"CERCLA"                                          --       Section 3.01(y)
"Citizens National"                               --       Section 3.01(a)
"Closing Date"                                    --       Section 9.01
"Closing"                                         --       Section 9.01
"Code"                                            --       Preamble
"Compensation and Benefit Plans"                  --       Section 3.01(s)
"Confidentiality Agreement"                       --       Section 7.06
"Constituent Corporations"                        --       Preamble
"Consultants"                                     --       Section 3.01(s)
"Costs"                                           --       Section 6.07(a)
"Converted Option"                                --       Section 7.01
"CRA"                                             --       Section 3.01(jj)
"Determination Date"                              --       Section 11.01(d)
"Directors"                                       --       Section 3.01(s)
"DOL"                                             --       Section 3.01(s)
"Effective Time"                                  --       Section 1.02
"Employees"                                       --       Section 3.01(s)
"Environmental Law"                               --       Section 3.01(y)
"ERISA"                                           --       Section 3.01(s)
"ERISA Affiliate"                                 --       Section 3.01(s)
"ERISA Affiliate Plan"                            --       Section 3.01(s)
"Exchange Act"                                    --       Section 3.01(hh)
"Exchange Agent"                                  --       Section 2.02(a)
"Exchange Fund"                                   --       Section 2.02(a)
"Exchange Ratio"                                  --       Section 2.01(b)
"FDIC"                                            --       Section 3.01(k)
"Federal Reserve"                                 --       Section 3.01(k)
"Final Index Price"                               --       Section 11.01(d)
"Final Price"                                     --       Section 11.01(d)
"GAAP"                                            --       Section 3.01(f)
"Governmental Authority"                          --       Section 3.01(p)
"Hazardous Substances"                            --       Section 3.01(y)
"Indemnified Party"                               --       Section 6.07(a)
"Index Group"                                     --       Section 11.01(d)
"Initial Index Price"                             --       Section 11.01(d)
"Insurance Amount"                                --       Section 6.07(b)


                                      -iv-
<PAGE>   95

"IRS"                                             --       Section 3.01(l)
"Joint Proxy Statement"                           --       Section 5.03(b)
"Joint Proxy Statement/Prospectus"                --       Section 7.08(a)
"Loan Assets"                                     --       Section 3.01(i)
"Loan Documentation"                              --       Section 3.01(i)
"material adverse effect"                         --       Section 3.01(a)
"material"                                        --       Section 3.01(a)
"Merger Shares"                                   --       Section 2.01(b)
"Merger"                                          --       Preamble
"OCC"                                             --       Section 3.01(k)
"ODFI"                                            --       Section 3.01(k)
"Officers"                                        --       Section 3.01(s)
"OGCL"                                            --       Section 1.01
"OTS"                                             --       Section 3.01(k)
"Park"                                            --       Preamble
"Park Balance Sheet Date"                         --       Section 4.01(f)
"Park Dissenting Shares"                          --       Section 2.02(1)
"Park Financial Statements"                       --       Section 4.01(f)
"Park Meeting"                                    --       Section 6.06(b)
"Park Shareholders' Adoption"                     --       Section 11.01(b)
"Park Shares"                                     --       Preamble
"Park Stock Option Plan"                          --       Section 4.01(c)
"PBGC"                                            --       Section 3.01(s)
"PCBs"                                            --       Section 3.01(y)
"Pension Plan"                                    --       Section 3.01(s)
"Registration Statement"                          --       Section 7.08(a)
"Regulatory Authorities"                          --       Section 3.01(o)
"Rule 145 Affiliates"                             --       Section 5.06(a)
"SEC"                                             --       Section 3.01(c)
"Secretary of State"                              --       Section 1.02
"Securities Act"                                  --       Section 3.01(u)
"Security"                                        --       Preamble
"Security Balance Sheet Date"                     --       Section 3.01(f)
"Security Certificates"                           --       Section 2.02(a)
"Security Disclosure Schedule"                    --       Preamble
"Security Dissenting Share"                       --       Section 2.02(k)
"Security Financial Statements"                   --       Section 3.01(f)
"Security Meeting"                                --       Section 5.03(b)
"Security National"                               --       Section 3.01(a)
"Security Real Properties"                        --       Section 3.01(m)
"Security Shares"                                 --       Preamble
"Security Shareholders' Adoption"                 --       Section 11.01(b)
"Security Split Dollar Plan"                      --       Section 7.12
"Security Stock Option Plans"                     --       Section 3.01(b)
"Security Stock Options"                          --       Section 3.01(b)
"Security Subsidiaries"                           --       Section 3.01(a)


                                      -v-
<PAGE>   96

"Security Subsidiary Real Estate Collateral"      --       Section 3.01(y)
"Security Voting Debt"                            --       Section 3.01(b)
"Starting Date"                                   --       Section 11.01(d)
"Starting Price"                                  --       Section 11.01(d)
"Subsidiary"                                      --       Section 3.01(c)
"Surviving Corporation"                           --       Section 1.01
"Takeover Laws"                                   --       Section 3.01(aa)
"Tax"                                             --       Section 3.01(l)
"Tax Returns"                                     --       Section 3.01(l)
"Third Savings"                                   --       Section 3.01(a)
"Total Security Shares Outstanding"               --       Section 2.01(b)
"trading days"                                    --       Section 2.02(e)
"Updated Security Disclosure Schedule"            --       Section 5.02










                                      -vi-
<PAGE>   97




                          AGREEMENT AND PLAN OF MERGER
                          ----------------------------

                  THIS AGREEMENT AND PLAN OF MERGER (the "Agreement"), dated as
of November 20, 2000, is made and entered into by and between Park National
Corporation, an Ohio corporation ("Park"), and Security Banc Corporation, an
Ohio corporation ("Security") (Park and Security are sometimes hereinafter
collectively referred to as the "Constituent Corporations").

                              W I T N E S S E T H:

                  WHEREAS, the Boards of Directors of Security and Park have
each determined that it is in the best interests of their respective
corporations and shareholders for Security to merge with and into Park (the
"Merger"), upon the terms and subject to the conditions set forth in and
pursuant to the terms of this Agreement; and

                  WHEREAS, the Boards of Directors of Security and Park have
each approved this Agreement and the consummation of the transactions
contemplated hereby; and

                  WHEREAS, as a result of the Merger, in accordance with the
terms of this Agreement, Security will cease to have a separate corporate
existence, and shareholders of Security will receive from Park in exchange for
each common share, $1.5625 par value, of Security (the "Security Shares"), the
number of common shares, without par value, of Park (the "Park Shares")
calculated in accordance with the terms of this Agreement; and

                  WHEREAS, it is the intention of Security and Park that the
Merger contemplated by this Agreement be accounted for under the
"pooling-of-interests" accounting method; and

                  WHEREAS, for Federal income tax purposes, it is intended that
the Merger contemplated by this Agreement qualify as a "reorganization" under
the provisions of Section 368(a) of the Internal Revenue Code of 1986, as
amended (the "Code"); and

                  WHEREAS, Security has previously provided to Park a schedule
disclosing additional information about Security (the "Security Disclosure
Schedule");

                  NOW, THEREFORE, in consideration of the premises and the
respective representations, warranties, covenants, agreements and conditions
hereinafter set forth, Security and Park, intending to be legally bound hereby,
agree as follows:




<PAGE>   98

                                   ARTICLE ONE
                                   THE MERGER

         1.01. MERGER; SURVIVING CORPORATION

         Upon the terms and subject to the conditions of this Agreement, at the
Effective Time (as defined in Section 1.02), Security shall merge with and into
Park in accordance with the General Corporation Law of the State of Ohio (the
"OGCL"). Park shall be the continuing and surviving corporation in the Merger,
shall continue to exist under the laws of the State of Ohio, and shall be the
only one of the Constituent Corporations to continue its separate corporate
existence after the Effective Time. As used in this Agreement, the term
"Surviving Corporation" refers to Park at and after the Effective Time. As a
result of the Merger, the outstanding shares of capital stock and the treasury
shares of the Constituent Corporations shall be converted in the manner provided
in Article Two.

         1.02. EFFECTIVE TIME

         The Merger shall become effective upon the later of (a) the filing of
the appropriate certificate of merger with the Secretary of State of the State
of Ohio (the "Secretary of State") or (b) such time thereafter as is agreed to
in writing by Park and Security and so provided in the certificate of merger.
The date and time at which the Merger shall become effective is referred to in
this Agreement as the "Effective Time."

         1.03. EFFECTS OF THE MERGER

         At the Effective Time:

         (a)      the Articles of Incorporation of Park as in effect immediately
                  prior to the Effective Time shall be the articles of the
                  Surviving Corporation;

         (b)      the Regulations of Park as in effect immediately prior to the
                  Effective Time shall be the regulations of the Surviving
                  Corporation; and

         (c)      the authorized number of directors of the Surviving
                  Corporation shall be the authorized number of directors of
                  Park immediately prior to the Effective Time. At the Effective
                  Time, each individual who is serving as a director of Park
                  immediately prior to the Effective Time shall become a
                  director of the Surviving Corporation and each such individual
                  shall serve as a director of the Surviving Corporation for the
                  balance of the term for which such individual was elected a
                  director of Park. In addition, Harry O. Egger shall become a
                  director of the Surviving Corporation and shall have a term
                  expiring at the annual meeting of the shareholders of the
                  Surviving Corporation to be held in 2002. Each director of the
                  Surviving Corporation shall serve as such until his or her
                  successor is duly elected and qualified in the manner provided
                  in the articles and regulations of the Surviving Corporation
                  or as otherwise provided by law or until his or her earlier
                  death, resignation or removal in the manner provided in the
                  articles



                                      -2-
<PAGE>   99

                  and regulations of the Surviving Corporation or as otherwise
                  provided by law;

         (d)      each individual who is an officer of Park immediately prior to
                  the Effective Time shall become an officer of the Surviving
                  Corporation with each such individual to hold the same office
                  in the Surviving Corporation, in accordance with the
                  regulations thereof, as he held in Park immediately prior to
                  the Effective Time. In addition, Harry O. Egger shall become
                  Vice Chairman of the Surviving Corporation in accordance with
                  the regulations thereof; and

         (e)      the Merger shall have the effects prescribed in the OGCL.


                                   ARTICLE TWO
                 CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES

         2.01. CONVERSION OF SECURITY SHARES

         At the Effective Time, by virtue of the Merger and without any action
on the part of the holder thereof:

         (a)      Conversion of Security Shares. Subject to Sections 2.01(c) and
                  2.02, each Security Share issued and outstanding immediately
                  prior to the Effective Time shall be converted into that
                  number of fully paid and non-assessable Park Shares equal to
                  the Exchange Ratio as defined in Section 2.01(b) of this
                  Agreement. After the Effective Time, all such Security Shares
                  shall no longer be outstanding and each certificate previously
                  representing any Security Shares shall thereafter represent
                  the Park Shares into which such Security Shares have been
                  converted. Certificates previously representing Security
                  Shares shall be exchanged for certificates representing whole
                  Park Shares (and cash in lieu of fractional Park Share
                  interests) issued in consideration therefor upon the surrender
                  of such certificates in accordance with Section 2.02, without
                  interest.

         (b)      Exchange Ratio.

                  (i)      The Exchange Ratio shall be equal to:

                                   3,350,000 (THE "Merger Shares")
                           ------------------------------------------------
                                   Total Security Shares Outstanding
                                   (as defined in Section 2.01(b)(ii))

                  (ii)     "Total Security Shares Outstanding" shall mean the
                           total number of Security Shares issued and
                           outstanding immediately prior to the Effective Time
                           (other than Security Shares held in treasury by
                           Security).




                                      -3-
<PAGE>   100

                  (iii)    The Exchange Ratio shall be subject to adjustment in
                           accordance with Section 2.02(m).

         (c)      Cancellation of Treasury Shares; Security Shares Owned by
                  Park. All Security Shares held by Security as treasury shares
                  shall be cancelled and retired and shall cease to exist and no
                  Park Shares or other consideration shall be delivered in
                  exchange therefor. All Security Shares, if any, that are
                  beneficially owned by Park shall become treasury shares of the
                  Surviving Corporation.

         2.02.    EXCHANGE OF CERTIFICATES

         (a)      Exchange Agent. At or prior to the Effective Time, Park shall
                  deposit, or shall cause to be deposited, with First-Knox
                  National Bank (the "Exchange Agent"), for the benefit of the
                  holders of certificates which immediately prior to the
                  Effective Time evidenced Security Shares (the "Security
                  Certificates"), for exchange in accordance with this Article
                  Two, certificates representing Park Shares and an estimated
                  amount of cash necessary to pay cash in lieu of fractional
                  Park Share interests in accordance with Section 2.02(e) (such
                  certificates for Park Shares, together with any dividends or
                  distributions with a record date occurring on or after the
                  Effective Time with respect thereto, and such cash for
                  fractional Park Share interests being hereinafter referred to
                  as the "Exchange Fund") issuable pursuant to Section 2.01 in
                  exchange for such Security Shares.

         (b)      Exchange Procedures. As soon as reasonably practicable after
                  the Effective Time, the Surviving Corporation shall cause the
                  Exchange Agent to mail to each holder of record of Security
                  Shares immediately prior to the Effective Time, (i) a letter
                  of transmittal (which shall specify that delivery shall be
                  effected, and risk of loss and title to the Security
                  Certificates shall pass, only upon delivery of such Security
                  Certificates to the Exchange Agent, and which shall be in such
                  form and have such other provisions as the Surviving
                  Corporation may reasonably specify) and (ii) instructions for
                  use in effecting the surrender of the Security Certificates in
                  exchange for certificates representing Park Shares and cash in
                  lieu of fractional Park Share interests. Upon surrender by
                  such holder of a Security Certificate or Certificates
                  evidencing all Security Shares standing in such holder's name
                  for cancellation to the Exchange Agent together with such
                  letter of transmittal, duly executed, the holder of such
                  Security Certificate or Certificates shall be entitled to
                  receive in exchange therefor a certificate representing the
                  number of whole Park Shares, and/or a check in respect of any
                  fractional Park Share interests, which such holder has the
                  right to receive in respect of the Security Certificate or
                  Certificates surrendered pursuant to the provisions of this
                  Article Two (after taking into account all Security Shares
                  then held by such holder), and the





                                      -4-
<PAGE>   101

                  Security Certificate or Certificates so surrendered shall
                  forthwith be canceled. In the event of a transfer of ownership
                  of Security Shares which is not registered in the transfer
                  records of Security, a certificate representing the proper
                  number of Park Shares, and/or a check in respect of any
                  fractional Park Share interests, may be issued to a transferee
                  if the Security Certificate representing such Security Shares
                  is presented to the Exchange Agent, accompanied by all
                  documents required to evidence and effect such transfer and by
                  evidence that any applicable share transfer taxes have been
                  paid. Until surrendered as contemplated by this Section 2.02,
                  each Security Certificate shall be deemed at any time after
                  the Effective Time for all corporate purposes (except as
                  provided in Section 2.02(c)) to represent only the number of
                  whole Park Shares into which the Security Shares represented
                  by such Security Certificate have been converted as provided
                  in this Article Two and the right to receive upon such
                  surrender cash in lieu of any fractional Park Share interests
                  as contemplated by this Section 2.02.

         (c)      Distributions with Respect to Unexchanged Shares; Voting.

                  (i)      Dividends or other distributions declared or made
                           after the Effective Time with respect to Park Shares
                           with a record date after the Effective Time shall be
                           paid to the holder of any unsurrendered Security
                           Certificate with respect to the Park Shares
                           represented thereby, and any cash payment in lieu of
                           fractional Park Shares shall be paid to any such
                           holder pursuant to Section 2.02(e), only after
                           surrender of such Security Certificate by the holder
                           thereof. Subject to the effect of applicable laws,
                           following surrender of any such Security Certificate,
                           there shall be paid to the holder of the certificates
                           representing whole Park Shares issued in exchange
                           therefor, without interest, (A) as promptly as
                           practicable after the time of such surrender, the
                           amount of any cash payable with respect to a
                           fractional Park Share interest to which such holder
                           is entitled pursuant to Section 2.02(e) and the
                           amount of dividends or other distributions with a
                           record date after the Effective Time theretofore paid
                           (but withheld pursuant to the immediately preceding
                           sentence) with respect to such whole Park Shares, and
                           (B) at the appropriate payment date, the amount of
                           dividends or other distributions with a record date
                           after the Effective Time but prior to surrender and a
                           payment date subsequent to surrender payable with
                           respect to such whole Park Shares.

                  (ii)     Former holders of record as of the Effective Time of
                           Security Shares shall not be entitled to vote the
                           Park Shares into which their Security Shares shall
                           have been converted on matters submitted to the
                           shareholders of Park until the Security Certificates
                           formerly representing such Security Shares shall have
                           been surrendered in







                                      -5-
<PAGE>   102

                           accordance with this Section 2.02 or certificates
                           evidencing such Park Shares shall have been issued in
                           exchange therefor.

                  (d)      No Further Ownership Rights in Security Shares. All
                           Park Shares issued upon conversion of Security Shares
                           in accordance with the terms hereof (including any
                           cash paid pursuant to Section 2.02(c) or 2.02(e))
                           shall be deemed to have been issued in full
                           satisfaction of all rights pertaining to such
                           Security Shares, subject, however, to the Surviving
                           Corporation's obligation to pay any dividends or make
                           any other distributions with a record date prior to
                           the Effective Time which may have been declared or
                           made by Security on such Security Shares in
                           accordance with the terms of this Agreement on or
                           prior to the Effective Time and which remain unpaid
                           at the Effective Time. If, after the Effective Time,
                           Security Certificates are presented to the Surviving
                           Corporation for any reason, they shall be canceled
                           and exchanged as provided in this Article Two.

                  (e)      No Fractional Park Shares.

                           (i)      No certificates or scrip representing
                                    fractional Park Shares shall be issued upon
                                    the surrender for exchange of Security
                                    Certificates evidencing Security Shares, and
                                    such fractional Park Share interests will
                                    not entitle the owner thereof to vote or to
                                    any rights of a shareholder of the Surviving
                                    Corporation.

                           (ii)     Each holder of Security Shares who would
                                    otherwise be entitled to receive a
                                    fractional Park Share shall receive from the
                                    Exchange Agent an amount of cash equal to
                                    the product obtained by multiplying (a) the
                                    fractional Park Share interest to which such
                                    holder (after taking into account all
                                    Security Shares held at the Effective Time
                                    by such holder) would otherwise be entitled
                                    by (b) the Average Closing Price of Park
                                    Shares (as defined below in Section
                                    2.02(e)(iii) below). No interest shall be
                                    payable with respect to such cash payment.

                           (iii)    The "Average Closing Price of Park Shares"
                                    shall mean the average of the closing sale
                                    prices of a Park Share on the American Stock
                                    Exchange ("AMEX") (as reported in The Wall
                                    Street Journal or, if not reported therein,
                                    in another authoritative source) during the
                                    period of 20 trading days (as hereinafter
                                    defined in this Section 2.02(e)(iii))
                                    immediately preceding the tenth day prior to
                                    the Effective Time. As used in this
                                    Agreement, "trading days" shall mean days on
                                    which actual trades of Park Shares occur.

                  (f)      Termination of Exchange Fund. Any portion of the
                           Exchange Fund which remains undistributed to the
                           shareholders of Security for six months after the
                           Effective Time shall be delivered to the Surviving
                           Corporation, upon





                                      -6-
<PAGE>   103

                           demand, and any shareholders of Security who have not
                           theretofore complied with this Article Two shall
                           thereafter look only to the Surviving Corporation for
                           payment of their claim for Park Shares, any cash in
                           lieu of fractional Park Share interest and any
                           dividends or distributions with respect to Park
                           Shares, in each case without interest.

                  (g)      No Liability. None of Park, Security, the Exchange
                           Agent or the Surviving Corporation shall be liable to
                           any former holder of Security Shares for Park Shares
                           (or dividends or distributions with respect thereto)
                           or cash in lieu of a fractional Park Share interest
                           delivered to a public official pursuant to any
                           applicable abandoned property, escheat or similar
                           law.

                  (h)      Share Transfer Books. Unless otherwise required by
                           Section 1701.85 of the OGCL, after the Effective Time
                           there shall be no further registration of transfers
                           on the share transfer books of the Surviving
                           Corporation of the Security Shares which were
                           outstanding immediately prior to the Effective Time.

                  (i)      Lost Certificates. If there shall be delivered to the
                           Exchange Agent by any person who is unable to produce
                           any Security Certificate for Security Shares for
                           surrender to the Exchange Agent in accordance with
                           this Section 2.02:

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

                           (b)      Such security or indemnity as may be
                                    requested by the Surviving Corporation to
                                    save it harmless (which shall not include
                                    the requirement to obtain a third party bond
                                    or surety); and

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

                           then the Exchange Agent, in the absence of actual
                           notice to it that any Security Shares theretofore
                           represented by any such Security Certificate have
                           been acquired by a bona fide purchaser, shall deliver
                           to such person the Park Shares (and cash in lieu of
                           fractional Park Share interests) that such person
                           would have been entitled to receive upon surrender of
                           each such lost, wrongfully taken or destroyed
                           Security Certificate.

                  (j)      Waiver. The Surviving Corporation may from time to
                           time, in the case of one or more persons, waive one
                           or more of the rights provided to it in this




                                      -7-
<PAGE>   104

                           Article Two to withhold certain payments, deliveries
                           and distributions; and no such waiver shall
                           constitute a waiver of its rights thereafter to
                           withhold any such payment, delivery or distribution
                           in the case of any person.

                  (k)      Security Shareholders' Dissenters' Rights. Anything
                           contained in this Agreement or elsewhere to the
                           contrary notwithstanding, if any holder of an
                           outstanding Security Share shall properly exercise
                           dissenters' rights with respect thereto in accordance
                           with Section 1701.85 of the OGCL (a "Security
                           Dissenting Share"), then:

                           (i)      Each such Security Dissenting Share shall
                                    nevertheless be deemed to be extinguished at
                                    the Effective Time as provided elsewhere in
                                    this Agreement;

                           (ii)     Each person perfecting such dissenter's
                                    rights shall thereafter have only such
                                    rights (and shall have such obligations) as
                                    are provided in Section 1701.85 of the OGCL,
                                    and the Surviving Corporation shall not be
                                    required to deliver any Park Shares or cash
                                    payments to such person in substitution for
                                    each such Security Dissenting Share in
                                    accordance with this Agreement; provided,
                                    however, that if any such person shall have
                                    failed to perfect or shall withdraw or lose
                                    such holder's rights under division (D) of
                                    Section 1701.85 of the OGCL, each such
                                    holder's Security Dissenting Shares shall
                                    thereupon be deemed to have been converted
                                    as of the Effective Time into the right to
                                    receive Park Shares and cash in lieu of
                                    fractional Park Share interests in
                                    accordance with the Exchange Ratio, without
                                    any interest thereon, pursuant to Section
                                    2.01.

                           No holder of Security Dissenting Shares shall be
                           entitled to submit a letter of transmittal, and any
                           letter of transmittal submitted by a holder of
                           Security Dissenting Shares shall be invalid.

                  (l)      Park Shareholders' Dissenters' Rights. Anything
                           contained in this Agreement to the contrary
                           notwithstanding, if any person shall perfect
                           dissenter's rights in respect of one or more Park
                           Shares, in accordance with Section 1701.85 of the
                           OGCL, then all of the rights accruing from the Park
                           Shares which are outstanding immediately before the
                           Effective Time and which are held by any shareholders
                           who have not voted such Park Shares in favor of the
                           adoption of this Agreement and who shall have
                           delivered to Park a written demand for appraisal of
                           such Park Shares in the manner provided in Section
                           1701.85 of the OGCL shall be suspended at the
                           Effective Time; provided, however, that (i) the
                           holders of such Park Shares (hereinafter referred to
                           as "Park Dissenting Shares") upon compliance with the
                           provisions of Section 1701.85 of the OGCL, shall be
                           entitled to payment of the appraised value of such
                           Park Dissenting Shares




                                      -8-
<PAGE>   105

                           in accordance with Section 1701.85 of the OGCL and
                           (ii) the rights accruing from Park Dissenting Shares
                           shall remain suspended until the earlier of (A) the
                           date on which such holder, upon compliance with the
                           provisions of Section 1701.85 of the OGCL,
                           establishes the right to the payment of the appraised
                           value of such Park Dissenting Shares in accordance
                           with the provisions of Section 1701.85 of the OGCL
                           and such value is paid to such holder, at which time
                           such Park Dissenting Shares shall be cancelled and
                           extinguished in consideration and exchange for such
                           payment, and (B) the date on which either the demand
                           for appraisal of such Park Dissenting Shares is
                           withdrawn with the consent of Park or such holder
                           forfeits the rights to appraisal of such Park
                           Dissenting Shares by failing to establish such
                           holder's entitlement to appraisal rights in
                           accordance with Section 1701.85 of the OGCL, at which
                           time such Park Dissenting Shares shall be deemed to
                           be issued and outstanding.

                  (m)      Changes in Park Shares. In the event Park changes (or
                           establishes a record date for changing) the number of
                           Park Shares issued and outstanding prior to the
                           Effective Time as a result of a share split, share
                           dividend, recapitalization or similar transaction
                           with respect to the outstanding Park Shares and the
                           record date therefor shall be prior to the Effective
                           Time, or exchanges the Park Shares for a different
                           number or kind of shares or securities or is involved
                           in any transaction resulting in any of the foregoing,
                           the Exchange Ratio shall be proportionately adjusted.

                  2.03.    PARK SHARES

                  All Park Shares, if any, that are owned directly by Security
shall become treasury shares of the Surviving Corporation. Each other Park Share
issued and outstanding immediately prior to the Effective Time shall continue to
be issued and outstanding and unaffected by the Merger. Each Park Share held by
Park in treasury shall continue to be a treasury share of the Surviving
Corporation.

                                  ARTICLE THREE
                   REPRESENTATIONS AND WARRANTIES OF SECURITY

                  3.01.    REPRESENTATIONS AND WARRANTIES OF SECURITY

                  Security hereby represents and warrants to Park that:

                  (a)      Corporate Status.

                           (i)      Security is an Ohio corporation and a bank
                                    holding company registered under the Bank
                                    Holding Company Act of 1956, as amended (the
                                    "BHC Act"); is duly organized, validly
                                    existing and in good standing under the laws
                                    of Ohio; and has the full corporate




                                      -9-
<PAGE>   106

                                    power and authority to own its property, to
                                    carry on its business as presently
                                    conducted, and to enter into and, subject to
                                    the required adoption of this Agreement by
                                    the Security shareholders and the obtaining
                                    of appropriate approvals of Governmental
                                    Authorities and Regulatory Authorities,
                                    perform its obligations under this Agreement
                                    and consummate the transactions contemplated
                                    by this Agreement. Security is not qualified
                                    to do business in any other jurisdiction or
                                    required to be so qualified to do business
                                    in any other jurisdiction except where the
                                    failure to be so qualified would not have a
                                    material adverse effect on Security. Copies
                                    of the articles of incorporation and
                                    regulations of Security and all amendments
                                    thereto have been delivered to Park by
                                    Security in Section 3.01(a) of the Security
                                    Disclosure Schedule.

                           (ii)     Security National Bank and Trust Company
                                    ("Security National"), Citizens National
                                    Bank ("Citizens National") and The Third
                                    Savings and Loan Company ("Third Savings"
                                    and, collectively with Security National and
                                    Citizens National, the "Security
                                    Subsidiaries") are the only Subsidiaries (as
                                    that term is defined in Section 3.01(c)) of
                                    Security. Each of Security National and
                                    Citizens National is a national banking
                                    association; is duly organized, validly
                                    existing and in good standing under the laws
                                    of the United States of America; and has the
                                    full corporate power and authority to own
                                    its property, and to carry on its business
                                    as presently conducted. Third Savings is an
                                    Ohio state-chartered savings association; is
                                    duly organized, validly existing and in good
                                    standing under the laws of the State of
                                    Ohio; and has full corporate power and
                                    authority to own its property, and to carry
                                    on its business as presently conducted. No
                                    Security Subsidiary is qualified to do
                                    business in any other jurisdiction or
                                    required to be qualified to do business in
                                    any other jurisdiction except where the
                                    failure to be so qualified would not have a
                                    material adverse effect on such Security
                                    Subsidiary. Copies of the governing
                                    instruments of each Security Subsidiary and
                                    all amendments thereto have been delivered
                                    to Park in Section 3.01(a) of the Security
                                    Disclosure Schedule.

                           (iii)    As used in this Agreement, (A) any reference
                                    to any event, change or effect being
                                    "material" with respect to any entity means
                                    an event, change or effect which is material
                                    in relation to the financial condition,
                                    properties, assets, liabilities, businesses
                                    or results of operations of such entity and
                                    its subsidiaries taken as a whole and (B)
                                    the term "material adverse effect" means,
                                    with respect to an entity, a material
                                    adverse effect on the financial condition,
                                    properties, assets, liabilities, businesses
                                    or results of operations of such entity and
                                    its subsidiaries taken as a whole or on the
                                    ability of







                                      -10-
<PAGE>   107

                                    such entity to perform without material
                                    delay its obligations under this Agreement
                                    or consummate the Merger and the other
                                    material transactions contemplated by this
                                    Agreement.

                  (b)      Capitalization of Security.

                           (i)      The authorized capital of Security consists
                                    solely of 18,000,000 common shares, $1.5625
                                    par value per share, of which 11,777,700
                                    Security Shares are issued and outstanding
                                    and 911,558 Security Shares are held in
                                    treasury by Security. All outstanding
                                    Security Shares have been duly authorized
                                    and are validly issued, fully paid and
                                    non-assessable, and were not issued in
                                    violation of the preemptive rights of any
                                    person. All Security Shares issued have been
                                    issued in compliance with all applicable
                                    federal and state securities laws. As of the
                                    date of this Agreement, 174,999 Security
                                    Shares were reserved for issuance upon the
                                    exercise of outstanding stock options (the
                                    "Security Stock Options") granted under the
                                    Security Banc Corporation 1987 Stock Option
                                    Plan, the Security Banc Corporation 1995
                                    Stock Option Plan and the Security Banc
                                    Corporation 1998 Stock Option Plan
                                    (collectively, the "Security Stock Option
                                    Plans"). Security has furnished to Park a
                                    true, complete and correct copy of each of
                                    the Security Stock Option Plans and a list
                                    of all participants therein which identifies
                                    the number of Security Shares subject to
                                    Security Stock Options held by each
                                    participant, the exercise price or prices of
                                    such Security Stock Options and the dates
                                    each Security Stock Option was granted,
                                    becomes exercisable and expires.

                           (ii)     As of the date of this Agreement, except for
                                    this Agreement and the Security Stock
                                    Options, there are no options, warrants,
                                    calls, rights, commitments or agreements of
                                    any character to which Security is a party
                                    or by which it is bound obligating Security
                                    to issue, deliver or sell, or cause to be
                                    issued, delivered or sold, any additional
                                    Security Shares or obligating Security to
                                    grant, extend or enter into any such option,
                                    warrant, call, right, commitment or
                                    agreement. As of the date of this Agreement,
                                    there are no outstanding contractual
                                    obligations of Security to repurchase,
                                    redeem or otherwise acquire any Security
                                    Shares except for such obligations arising
                                    under the Security Stock Option Agreement.

                           (iii)    Except as disclosed in Section 3.01(b) of
                                    the Security Disclosure Schedule, since
                                    September 30, 1998, Security has not (A)
                                    issued or permitted to be issued any
                                    Security Shares, or securities exercisable
                                    for or convertible into Security Shares,
                                    other than upon exercise of the Security
                                    Stock Options granted prior to the date
                                    hereof under the Security Stock Option
                                    Plans; (B) repurchased,






                                      -11-
<PAGE>   108

                                    redeemed or otherwise acquired, directly or
                                    indirectly through any Security Subsidiary
                                    or otherwise, any Security Shares; or (C)
                                    declared, set aside, made or paid to the
                                    shareholders of Security dividends or other
                                    distributions on the outstanding Security
                                    Shares, other than (x) regular quarterly
                                    cash dividends on the Security Shares at a
                                    rate not in excess of the regular quarterly
                                    cash dividends most recently declared by
                                    Security prior to the date of this Agreement
                                    and (y) the quarterly dividend in the amount
                                    of $0.20 per Security Share declared in
                                    respect of the fiscal quarter ended December
                                    31, 2000.

                           (iv)     No bonds, debentures, notes or other
                                    indebtedness of Security having the right to
                                    vote on any matters on which Security
                                    shareholders may vote ("Security Voting
                                    Debt") are issued or outstanding.

                  (c)      Subsidiaries. The Security Subsidiaries are the only
                           Subsidiaries of Security. Security owns of record and
                           beneficially all of the issued and outstanding equity
                           securities of each Security Subsidiary. There are no
                           options, warrants, calls, rights, commitments or
                           agreements of any character to which Security or any
                           Security Subsidiary is a party or by which any of
                           them is bound obligating any Security Subsidiary to
                           issue, deliver or sell, or cause to be issued,
                           delivered or sold, additional equity securities of
                           any Security Subsidiary (other than to Security) or
                           obligating Security or any Security Subsidiary to
                           grant, extend or enter into any such option, warrant,
                           call, right, commitment or agreement. There are no
                           contracts, commitments, understandings or
                           arrangements relating to Security's rights to vote or
                           to dispose of the equity securities of any Security
                           Subsidiary which it owns. All of the equity
                           securities of the Security Subsidiaries held by
                           Security are fully paid and non-assessable (except as
                           provided in 12 U.S.C. Section 55 in the case of
                           Security National and Citizens National and any
                           comparable provision of applicable state law in the
                           case of Third Savings) and are owned by Security free
                           and clear of any charge, mortgage, pledge, security
                           interest, hypothecation, restriction, claim, option,
                           lien, encumbrance or interest of any persons
                           whatsoever. Except as disclosed in Section 3.01(c) of
                           the Security Disclosure Schedule, Security does not
                           own beneficially, directly or indirectly, any equity
                           securities or similar interests of any person, or any
                           interest in a partnership or joint venture of any
                           kind, other than the Security Subsidiaries.

                           For purposes of this Agreement, "Subsidiary" has the
                           meaning ascribed to it in Rule 1-02 of Regulation S-X
                           promulgated by the Securities and Exchange Commission
                           (the "SEC").





                                      -12-
<PAGE>   109

                  (d)      Corporate Proceedings. All corporate proceedings of
                           Security necessary to authorize the execution,
                           delivery and performance of this Agreement and the
                           consummation of the transactions contemplated hereby,
                           in each case by Security, have been duly and validly
                           taken, except for the adoption of this Agreement by
                           the holders of at least two-thirds of the outstanding
                           Security Shares entitled to vote thereon (which is
                           the only required shareholder vote thereon). The
                           Board of Directors of Security has recommended
                           adoption of this Agreement by the shareholders of
                           Security and directed that this Agreement be
                           submitted to the shareholders of Security for their
                           approval. This Agreement has been validly executed
                           and delivered by duly authorized officers of
                           Security. The Board of Directors of Security has
                           received the written opinion of Austin Associates,
                           Inc. to the effect that as of the date hereof, the
                           consideration to be received by the holders of
                           Security Shares in the Merger is fair to the holders
                           of Security Shares from a financial point of view.

                  (e)      Authorized and Effective Agreement. This Agreement
                           constitutes the legal, valid and binding obligation
                           of Security, enforceable against Security in
                           accordance with its terms, except as the same may be
                           limited by bankruptcy, insolvency, reorganization,
                           moratorium, fraudulent conveyance and other similar
                           laws relating to or affecting the enforcement of
                           creditors' rights generally, by general equitable
                           principles (regardless of whether enforceability is
                           considered in a proceeding in equity or at law) and
                           by an implied covenant of good faith and fair
                           dealing. Security has the absolute and unrestricted
                           right, power, authority and capacity to execute and
                           deliver this Agreement and, subject to the required
                           adoption of this Agreement by the Security
                           shareholders, the obtaining of appropriate approvals
                           by Regulatory Authorities and Governmental
                           Authorities and the expiration of applicable
                           regulatory waiting periods, to perform its
                           obligations under this Agreement.

                  (f)      Financial Statements of Security. Security has
                           furnished to Park accurate and complete copies of
                           consolidated financial statements of Security
                           consisting of (i) consolidated balance sheets as of
                           December 31, 1999 and 1998, and the related
                           consolidated statements of income, changes in
                           shareholders' equity and cash flows for the three
                           years ended December 31, 1999, including accompanying
                           notes and the report thereon of Ernst & Young LLP and
                           (ii) the unaudited consolidated balance sheet as of
                           September 30, 2000 (the "Security Balance Sheet
                           Date"), the related unaudited consolidated statements
                           of income for the three and nine months ended
                           September 30, 2000 and 1999, of changes in
                           shareholders' equity for the nine months ended
                           September 30, 2000 and 1999, and of cash flows for
                           the nine months ended September 30, 2000 and 1999
                           (collectively, all of such consolidated financial
                           statements are referred to as the "Security Financial
                           Statements"). The Security Financial Statements were
                           prepared in accordance with generally accepted





                                      -13-
<PAGE>   110

                           accounting principles ("GAAP") applied on a
                           consistent basis and present fairly, in all material
                           respects, the consolidated financial condition of
                           Security at the dates, and the consolidated results
                           of operations and cash flows for the periods, stated
                           therein; subject, in the case of the interim
                           statements, to normal year-end audit adjustments
                           which are not expected to be, individually or in the
                           aggregate, materially adverse to Security and the
                           absence of full footnotes.

                  (g)      Absence of Undisclosed Liabilities. Except as
                           disclosed in Section 3.01(g) of the Security
                           Disclosure Schedule, neither Security nor any
                           Security Subsidiary had any debt, obligation,
                           guarantee or liability at the Security Balance Sheet
                           Date, whether absolute, accrued, contingent or
                           otherwise that would be required to be reflected on
                           and reserved against in the Security Financial
                           Statements or in the notes thereto except for debts,
                           obligations, guarantees or liabilities which,
                           individually or in the aggregate, do not exceed
                           $50,000. Except as disclosed in Section 3.01(g) of
                           the Security Disclosure Schedule, all debts,
                           liabilities, guarantees and obligations of Security
                           and the Security Subsidiaries incurred since the
                           Security Balance Sheet Date have been incurred in the
                           ordinary course of business and are usual and normal
                           in amount both individually and in the aggregate.
                           Except as disclosed in Section 3.01(g) of the
                           Security Disclosure Schedule, neither Security nor
                           any Security Subsidiary is in default or breach of
                           any material agreement to which Security or the
                           Security Subsidiary is a party.

                  (h)      Absence of Changes. Except as set forth in Section
                           3.01(h) of the Security Disclosure Schedule, since
                           the Security Balance Sheet Date: (i) there has not
                           been any material adverse change in the business,
                           operations, assets or financial condition of Security
                           and the Security Subsidiaries taken as a whole, and,
                           to the knowledge of Security, no fact or condition
                           exists which Security believes will cause such a
                           material adverse change in the future; and (ii)
                           Security has not taken or permitted any of the
                           actions described in Section 5.01(b) of this
                           Agreement.

                  (i)      Loan Documentation. To the knowledge of Security, the
                           documentation ("Loan Documentation") governing or
                           relating to the loan and credit-related assets ("Loan
                           Assets") representing the loan portfolio of each
                           Security Subsidiary is legally sufficient for the
                           purposes intended thereby and creates enforceable
                           rights of such Security Subsidiary in accordance with
                           the terms of such Loan Documentation, subject to
                           applicable bankruptcy, insolvency, reorganization,
                           moratorium, fraudulent conveyance and other similar
                           laws relating to or affecting the enforcement of
                           creditors' rights generally, by general equitable
                           principles (regardless of whether enforceability is
                           considered in a proceeding in equity or at law) and
                           by an implied covenant of good faith and fair
                           dealing. Except as set forth in Section 3.01(i) of
                           the Security Disclosure Schedule, no debtor




                                      -14-
<PAGE>   111

                           under any of the Loan Documentation has asserted any
                           claim or defense with respect to the subject matter
                           thereof. Except as set forth in Section 3.01(i) of
                           the Security Disclosure Schedule, none of the
                           Security Subsidiaries is a party to a loan, including
                           any loan guaranty, with any director, executive
                           officer or five percent (5%) shareholder of Security
                           or any Security Subsidiary, or any person,
                           corporation or enterprise controlling, controlled by
                           or under common control with either Security or any
                           Security Subsidiary. All loans and extensions of
                           credit that have been made by a Security Subsidiary
                           and that are subject either to Sections 22(g) or
                           22(h) of the Federal Reserve Act, as amended, or to
                           12 C.F.R. Part 215 (Regulation O), comply therewith.

                  (j)      Allowance for Loan Losses. Except as set forth in
                           Section 3.01(j) of the Security Disclosure Schedule,
                           there is no loan which was made by any Security
                           Subsidiary and which is reflected as an asset of such
                           Security Subsidiary on the Security Financial
                           Statements that (i) is 90 days or more delinquent or
                           (ii) has been classified by examiners (regulatory or
                           internal) as "Substandard," "Doubtful" or "Loss." The
                           allowance for loan losses reflected on the Security
                           Financial Statements has been determined in
                           accordance with GAAP and in accordance with all rules
                           and regulations applicable to Security and the
                           Security Subsidiaries and is adequate in all material
                           respects. Security has considered all potential
                           losses known to Security to the best of its knowledge
                           in establishing the current allowance for loan losses
                           for each Security Subsidiary, other than such losses
                           that if incurred would not have a material adverse
                           effect on either Security or the appropriate Security
                           Subsidiary.

                  (k)      Reports and Records. Security and the Security
                           Subsidiaries have filed all reports and maintained
                           all records required to be filed or maintained by
                           them under the rules and regulations of the Board of
                           Governors of the Federal Reserve System (the "Federal
                           Reserve"), the Office of the Comptroller of the
                           Currency (the "OCC"), the Office of Thrift
                           Supervision (the "OTS"), the Ohio Division of
                           Financial Institutions (the "ODFI"), and the Federal
                           Deposit Insurance Corporation (the "FDIC"), except
                           for such reports and records the failure to file or
                           maintain would not reasonably be expected to have a
                           material adverse effect on Security or the applicable
                           Security Subsidiary. All such documents and reports
                           complied in all material respects with applicable
                           requirements of law and rules and regulations in
                           effect at the time such documents and reports were
                           filed and contained in all material respects the
                           information required to be stated therein. None of
                           such documents or reports, when filed, contained any
                           untrue statement of a material fact or omitted to
                           state a material fact required to be stated therein
                           or necessary in order to make the statements therein,
                           in light of the circumstances under which they were
                           made, not misleading.






                                      -15-
<PAGE>   112

                  (l)      Taxes. Except as set forth in Section 3.01(l) of the
                           Security Disclosure Letter, Security and the Security
                           Subsidiaries have timely filed all returns,
                           statements, reports and forms (including elections,
                           declarations, disclosures, schedules, estimates and
                           information returns) (collectively, the "Tax
                           Returns") with respect to all federal, state, local
                           and foreign income, gross income, gross receipts,
                           gains, premium, sales, use, ad valorem, transfer,
                           franchise, profits, withholding, payroll, employment,
                           excise, severance, stamp, occupancy, license, lease,
                           environmental, customs, duties, property, windfall
                           profits and all other taxes (including any interest,
                           penalties or additions to tax with respect thereto,
                           individually, a "Tax" and, collectively, "Taxes")
                           required to be filed with the appropriate tax
                           authority through the date of this Agreement. Such
                           Tax Returns are and will be true, correct and
                           complete in all material respects. Security and the
                           Security Subsidiaries have paid and discharged all
                           Taxes due from them, other than such Taxes that are
                           adequately reserved as shown on the Security
                           Financial Statements or have arisen in the ordinary
                           course of business since the Security Balance Sheet
                           Date. Except as set forth in Section 3.01(l) of the
                           Security Disclosure Letter, neither the Internal
                           Revenue Service (the "IRS") nor any other taxing
                           agency or authority, domestic or foreign, has
                           asserted, is now asserting or, to the knowledge of
                           Security, is threatening to assert against Security
                           or any Security Subsidiary any deficiency or claim
                           for additional Taxes. There are no unexpired waivers
                           by Security or any Security Subsidiary of any statute
                           of limitations with respect to Taxes. The accruals
                           and reserves for Taxes reflected in the Security
                           Financial Statements are adequate for the periods
                           covered. Security and the Security Subsidiaries have
                           withheld or collected and paid over to the
                           appropriate Governmental Authorities or are properly
                           holding for such payment all Taxes required by law to
                           be withheld or collected. There are no liens for
                           Taxes upon the assets of Security or any Security
                           Subsidiary, other than liens for current Taxes not
                           yet due and payable. Neither Security nor any
                           Security Subsidiary has agreed to make, or is
                           required to make, any adjustment under Section 481(a)
                           of the Code. Except as set forth in Section 3.01(l)
                           of the Security Disclosure Letter, or as may be
                           caused by any agreement entered into by Park, neither
                           Security nor any Security Subsidiary is a party to
                           any agreement, contract, arrangement or plan that has
                           resulted, or could result, individually or in the
                           aggregate, in the payment of "excess parachute
                           payments" within the meaning of Section 280G of the
                           Code. Neither Security nor any Security Subsidiary
                           has ever been a member of an affiliated group of
                           corporations, within the meaning of Section 1504 of
                           the Code, other than an affiliated group of which
                           Security is or was the common parent corporation. No
                           Tax is required to be withheld pursuant to Section
                           1445 of the Code as a result of the transactions
                           contemplated by this Agreement.





                                      -16-
<PAGE>   113

                  (m)      Property and Title. Section 3.01(m) of the Security
                           Disclosure Schedule lists and describes all real
                           property, and any leasehold interest in real
                           property, owned or held by Security or any Security
                           Subsidiary and used in the business of Security or
                           any Security Subsidiary (collectively, the "Security
                           Real Properties"). The Security Real Properties
                           constitute all of the real property and interests in
                           real property used in the businesses of Security and
                           the Security Subsidiaries. Copies of all leases of
                           real property to which Security or any Security
                           Subsidiary is a party have been provided to Park in
                           Section 3.01(m) of the Security Disclosure Schedule.
                           Such leasehold interests have not been assigned or
                           subleased. All Security Real Properties which are
                           owned by Security or any Security Subsidiary are free
                           and clear of all mortgages, liens, security
                           interests, defects, encumbrances, easements,
                           restrictions, reservations, conditions, covenants,
                           agreements, encroachments, rights of way and zoning
                           laws, except (i) those set forth in the Security
                           Financial Statements or Section 3.01(m) of the
                           Security Disclosure Schedule; (ii) easements,
                           restrictions, reservations, conditions, covenants,
                           rights of way, zoning laws and other defects and
                           irregularities in title and encumbrances which do not
                           materially impair the use thereof for the purposes
                           for which they are held; and (iii) the lien of
                           current taxes not yet due and payable. Security and
                           the Security Subsidiaries own, and are in rightful
                           possession of, and have good title to, all of the
                           other assets indicated in the Security Financial
                           Statements as being owned by Security or a Security
                           Subsidiary, free and clear of any charge, mortgage,
                           pledge, security interest, hypothecation,
                           restriction, claim, option, lien, encumbrance or
                           interest of any persons whatsoever except those
                           described in the Security Financial Statements or
                           Section 3.01(m) of the Security Disclosure Schedule
                           and except for those assets disposed of in the
                           ordinary course of business consistent with past
                           practices. All of the assets of Security and the
                           Security Subsidiaries are in good operating
                           condition, except for normal maintenance and routine
                           repairs, and are adequate to continue to conduct the
                           businesses of Security and the Security Subsidiaries
                           as such businesses are presently being conducted.

                  (n)      Legal Proceedings. Except as set forth in Section
                           3.01(n) of the Security Disclosure Schedule, there
                           are no actions, suits, proceedings, claims or
                           investigations pending or, to the knowledge of
                           Security and the Security Subsidiaries, threatened in
                           any court, before any governmental agency or
                           instrumentality or in any arbitration proceeding (i)
                           against Security or any Security Subsidiary which
                           would have a material adverse effect on Security; or
                           (ii) against or by Security or any Security
                           Subsidiary which would prevent the consummation of
                           this Agreement or any of the transactions
                           contemplated hereby or declare the same to be
                           unlawful or cause the rescission thereof.







                                      -17-
<PAGE>   114

                  (o)      Regulatory Matters. None of Security, the Security
                           Subsidiaries and the respective properties of
                           Security and the Security Subsidiaries is a party to
                           or subject to any order, judgment, decree, agreement,
                           memorandum of understanding or similar arrangement
                           with, or a commitment letter or similar submission
                           to, or extraordinary supervisory letter from, any
                           court or federal or state governmental agency or
                           authority, including any such agency or authority
                           charged with the supervision or regulation of
                           financial institutions (or their holding companies)
                           or issuers of securities or engaged in the insurance
                           of deposit (including, without limitation, the OCC,
                           the Federal Reserve, the OTS, the ODFI, the SEC and
                           the FDIC) or the supervision or regulation of
                           Security or any Security Subsidiary (collectively,
                           the "Regulatory Authorities"). Neither Security nor
                           any Security Subsidiary has been advised by any
                           Regulatory Authority that such Regulatory Authority
                           is contemplating issuing or requesting (or is
                           considering the appropriateness of issuing or
                           requesting) any such order, judgment, decree,
                           agreement, memorandum of understanding, commitment
                           letter, supervisory letter or similar submission.

                  (p)      No Conflict. Subject to the required adoption of this
                           Agreement by the shareholders of Security, receipt of
                           the required approvals of Regulatory Authorities and
                           Governmental Authorities, expiration of applicable
                           regulatory waiting periods, and required filings
                           under federal and state securities laws, the
                           execution, delivery and performance of this
                           Agreement, and the consummation of the transactions
                           contemplated by this Agreement, by Security do not
                           and will not (i) conflict with, or result in a
                           violation of, or result in the breach of or a default
                           (or which with notice or lapse of time would result
                           in a default) under, any provision of: (A) any
                           federal, state or local law, regulation, ordinance,
                           order, rule or administrative ruling of any
                           administrative agency or commission or other federal,
                           state or local governmental authority or
                           instrumentality (each, a "Governmental Authority")
                           applicable to Security or any Security Subsidiary or
                           any of their respective properties; (B) the articles
                           of incorporation or regulations of Security, the
                           articles of association or by-laws of Security
                           National or Citizens National or the articles of
                           incorporation and regulations of Third Savings; (C)
                           any material agreement, indenture or instrument to
                           which Security or any Security Subsidiary is a party
                           or by which it or its properties or assets may be
                           bound; or (D) any order, judgment, writ, injunction
                           or decree of any court, arbitration panel or any
                           Governmental Authority applicable to Security or any
                           Security Subsidiary; (ii) result in the creation or
                           acceleration of any security interest, mortgage,
                           option, claim, lien, charge or encumbrance upon or
                           interest in any property of Security or any Security
                           Subsidiary; or (iii) violate the terms or conditions
                           of, or result in the cancellation, modification,
                           revocation or suspension of, any material license,
                           approval, certificate, permit or authorization held
                           by Security or any Security Subsidiary.












                                      -18-
<PAGE>   115

                  (q)      Brokers, Finders and Others. Except for the fees paid
                           or payable to Austin Associates, Inc., there are no
                           fees or commissions of any sort whatsoever claimed
                           by, or payable by Security or any Security Subsidiary
                           to, any broker, finder, intermediary, attorney,
                           accountant or any other similar person in connection
                           with effecting this Agreement or the transactions
                           contemplated hereby, except for ordinary and
                           customary legal and accounting fees.

                  (r)      Employment Agreements. Except as disclosed in Section
                           3.01(r) of the Security Disclosure Schedule, neither
                           Security nor any Security Subsidiary is a party to
                           any employment, change in control, severance or
                           consulting agreement not terminable at will. Neither
                           Security nor any Security Subsidiary is a party to,
                           bound by or negotiating, any collective bargaining
                           agreement, nor are any of their respective employees
                           represented by any labor union or similar
                           organization. Security and Security Subsidiaries are
                           in compliance in all material respects with all
                           applicable laws respecting employment and employment
                           practices, terms and conditions of employment and
                           wages and hours, and neither Security nor any
                           Security Subsidiary has engaged in any unfair labor
                           practice.

                  (s)      Employee Benefit Plans.

                           (i)      Section 3.01(s)(i) of the Security
                                    Disclosure Schedule contains a complete and
                                    accurate list of all bonus, incentive,
                                    deferred compensation, pension (including,
                                    without limitation, Pension Plans defined
                                    below), retirement, profit-sharing, thrift,
                                    savings, employee stock ownership, stock
                                    bonus, stock purchase, restricted stock,
                                    stock option, severance, welfare (including,
                                    without limitation, "welfare plans" within
                                    the meaning of Section 3(1) of the Employee
                                    Retirement Income Security Act of 1974, as
                                    amended ("ERISA")), fringe benefit plans,
                                    employment or severance agreements and all
                                    similar practices, policies and arrangements
                                    maintained or contributed to (currently or
                                    within the last six years) by (A) Security
                                    or any Security Subsidiary and in which any
                                    employee or former employee (the
                                    "Employees"), consultant or former
                                    consultant (the "Consultants"), officer or
                                    former officer (the "Officers"), or director
                                    or former director (the "Directors") of
                                    Security or any Security Subsidiary
                                    participates or to which any such Employees,
                                    Consultants, Officers or Directors either
                                    participate or are parties or (B) any ERISA
                                    Affiliate (as defined below) (collectively,
                                    the "Compensation and Benefit Plans").
                                    Neither Security nor any Security Subsidiary
                                    has any commitment to create any additional
                                    Compensation and Benefit Plan or to modify
                                    or change any existing Compensation and
                                    Benefit Plan, except as otherwise
                                    contemplated by Sections 6.02, 7.01, and
                                    7.12 of this Agreement.











                                      -19-
<PAGE>   116

                           (ii)     Each Compensation and Benefit Plan has been
                                    operated and administered in all material
                                    respects in accordance with its terms and
                                    with applicable law, including, but not
                                    limited to, ERISA, the Code, the Securities
                                    Act (as defined in Section 3.01(u)), the
                                    Exchange Act (as defined in Section
                                    3.01(hh)), the Age Discrimination in
                                    Employment Act, or any regulations or rules
                                    promulgated thereunder, and all filings,
                                    disclosures and notices required by ERISA,
                                    the Code, the Securities Act, the Exchange
                                    Act, the Age Discrimination in Employment
                                    Act and any other applicable law have been
                                    timely made. Each Compensation and Benefit
                                    Plan which is an "employee pension benefit
                                    plan" within the meaning of Section 3(2) of
                                    ERISA (a "Pension Plan") and which is
                                    intended to be qualified under Section
                                    401(a) of the Code has received a favorable
                                    determination letter (including a
                                    determination that the related trust under
                                    such Compensation and Benefit Plan is exempt
                                    from tax under Section 501(a) of the Code)
                                    from the IRS and Security is not aware of
                                    any circumstances likely to result in
                                    revocation of any such favorable
                                    determination letter. There is no material
                                    pending or, to the knowledge of Security,
                                    threatened legal action, suit or claim
                                    relating to the Compensation and Benefit
                                    Plans other than routine claims for benefits
                                    thereunder. Neither Security nor any
                                    Security Subsidiary has engaged in a
                                    transaction, or omitted to take any action,
                                    with respect to any Compensation and Benefit
                                    Plan that would reasonably be expected to
                                    subject Security or any Security Subsidiary
                                    to a tax or penalty imposed by either
                                    Section 4975 of the Code or Section 502 of
                                    ERISA, assuming for purposes of Section 4975
                                    of the Code that the taxable period of any
                                    such transaction expired as of the date
                                    hereof.

                           (iii)    No liability (other than for payment of
                                    premiums to the Pension Benefit Guaranty
                                    Corporation ("PBGC") which have been made or
                                    will be made on a timely basis) under Title
                                    IV of ERISA has been or is expected to be
                                    incurred by Security or any Security
                                    Subsidiary with respect to any ongoing,
                                    frozen or terminated "single-employer plan,"
                                    within the meaning of Section 4001(a)(15) of
                                    ERISA, currently or formerly maintained by
                                    any of them, or any single-employer plan of
                                    any entity (an "ERISA Affiliate Plan") which
                                    is considered one employer with Security
                                    under Section 4001(a)(14) of ERISA or
                                    Section 414(b), (c) or (m) of the Code (an
                                    "ERISA Affiliate"). None of Security, the
                                    Security Subsidiaries or any ERISA Affiliate
                                    has contributed, or has been obligated to
                                    contribute, to a multiemployer plan under
                                    Subtitle E of Title IV of ERISA (as defined
                                    in ERISA Sections 3(37)(A) and 4001(a)(3))
                                    at any time since September 26, 1980. No
                                    notice of a "reportable event", within the
                                    meaning of Section 4043 of ERISA,






                                      -20-
<PAGE>   117

                                    for which the 30-day reporting requirement
                                    has not been waived, has been required to be
                                    filed for any Compensation and Benefit Plan
                                    or by any ERISA Affiliate Plan within the
                                    12-month period ending on the date hereof,
                                    and no such notice will be required to be
                                    filed as a result of the transactions
                                    contemplated by this Agreement. The PBGC has
                                    not instituted proceedings to terminate any
                                    Pension Plan or ERISA Affiliate Plan and, to
                                    Security's knowledge, no condition exists
                                    that presents a material risk that such
                                    proceedings will be instituted. There is no
                                    pending investigation or enforcement action
                                    by the PBGC, the Department of Labor (the
                                    "DOL"), the IRS or any other Governmental
                                    Authority with respect to any Compensation
                                    and Benefit Plan. Under each Pension Plan
                                    and ERISA Affiliate Plan, as of the date of
                                    the most recent actuarial valuation
                                    performed prior to the date of this
                                    Agreement, the actuarially determined
                                    present value of all "benefit liabilities",
                                    within the meaning of Section 4001(a)(16) of
                                    ERISA (as determined on the basis of the
                                    actuarial assumptions contained in such
                                    actuarial valuation of such Pension Plan or
                                    ERISA Affiliate Plan), did not exceed the
                                    then current value of the assets of such
                                    Pension Plan or ERISA Affiliate Plan and
                                    since such date there has been neither an
                                    adverse change in the financial condition of
                                    such Pension Plan or ERISA Affiliate Plan
                                    nor any amendment or other change to such
                                    Pension Plan or ERISA Affiliate Plan that
                                    would increase the amount of benefits
                                    thereunder which reasonably could be
                                    expected to change such result.

                           (iv)     All contributions required to be made under
                                    the terms of any Compensation and Benefit
                                    Plan or ERISA Affiliate Plan or any employee
                                    benefit arrangements under any collective
                                    bargaining agreement to which Security or
                                    any Security Subsidiary is a party have been
                                    timely made or have been reflected on the
                                    Security Financial Statements. Neither any
                                    Pension Plan nor any ERISA Affiliate Plan
                                    has an "accumulated funding deficiency"
                                    (whether or not waived) within the meaning
                                    of Section 412 of the Code or Section 302 of
                                    ERISA and all required payments to the PBGC
                                    with respect to each Pension Plan or ERISA
                                    Affiliate Plan have been made on or before
                                    their due dates. None of Security, the
                                    Security Subsidiaries or any ERISA Affiliate
                                    (x) has provided, or would reasonably be
                                    expected to be required to provide, security
                                    to any Pension Plan or to any ERISA
                                    Affiliate Plan pursuant to Section
                                    401(a)(29) of the Code, and (y) has taken
                                    any action, or omitted to take any action,
                                    that has resulted, or would reasonably be
                                    expected to result, in the imposition of a
                                    lien under Section 412(n) of the Code or
                                    pursuant to ERISA.













                                      -21-
<PAGE>   118

                           (v)      Except as disclosed in Section 3.01(s)(v) of
                                    the Security Disclosure Schedule, neither
                                    Security nor any Security Subsidiary has any
                                    obligations to provide retiree health and
                                    life insurance or other retiree death
                                    benefits under any Compensation and Benefit
                                    Plan, other than benefits mandated by
                                    Section 4980B of the Code. Except as
                                    disclosed in Section 3.01(s)(v) of the
                                    Security Disclosure Schedule, there has been
                                    no communication to Employees by Security or
                                    any Security Subsidiary that would
                                    reasonably be expected to promise or
                                    guarantee such Employees retiree health or
                                    life insurance or other retiree death
                                    benefits on a permanent basis.

                           (vi)     Security and the Security Subsidiaries do
                                    not maintain any Compensation and Benefit
                                    Plans covering foreign Employees.

                           (vii)    With respect to each Compensation and
                                    Benefit Plan, if applicable, Security has
                                    provided or made available to Park, true and
                                    complete copies of existing: (A)
                                    Compensation and Benefit Plan documents and
                                    amendments thereto; (B) trust instruments
                                    and insurance contracts; (C) two most recent
                                    Forms 5500 filed with the IRS; (D) most
                                    recent actuarial report and financial
                                    statement; (E) most recent summary plan
                                    description; (F) forms filed with the PBGC
                                    within the past year (other than for premium
                                    payments); (G) most recent determination
                                    letter issued by the IRS; (H) any Form 5310,
                                    Form 5310A, Form 5300 or Form 5330 filed
                                    within the past year with the IRS; and (I)
                                    most recent nondiscrimination tests
                                    performed under ERISA and the Code
                                    (including but not limited to Code Section
                                    401(k) and 401(m) tests).

                           (viii)   Except as disclosed on Section 3.01(s)(viii)
                                    of the Security Disclosure Schedule, the
                                    consummation of the transactions
                                    contemplated by this Agreement would not,
                                    directly or indirectly (including, without
                                    limitation, as a result of any termination
                                    of employment prior to or following the
                                    Effective Time), reasonably be expected to
                                    (A) entitle any Employee, Consultant or
                                    Director to any payment (including severance
                                    pay or similar compensation) or any increase
                                    in compensation, (B) result in the vesting
                                    or acceleration of any benefits under any
                                    Compensation and Benefit Plan or (C) result
                                    in any material increase in benefits payable
                                    under any Compensation and Benefit Plan.

                           (ix)     Except as disclosed on Section 3.01(s)(ix)
                                    of the Security Disclosure Schedule, neither
                                    Security nor any Security Subsidiary
                                    maintains any compensation plans, programs
                                    or arrangements the payments under which
                                    would not reasonably be expected to be
                                    deductible as a result of the limitations
                                    under Section 162(m) of the Code and the
                                    regulations issued thereunder.












                                      -22-
<PAGE>   119

                           (x)      Except as disclosed on Section 3.01(s)(x) of
                                    the Security Disclosure Schedule, as a
                                    result, directly or indirectly, of the
                                    transactions contemplated by this Agreement
                                    (including, without limitation, as a result
                                    of any termination of employment prior to or
                                    following the Effective Time), none of Park,
                                    Security or the Surviving Corporation, or
                                    any of their respective Subsidiaries will be
                                    obligated to make a payment that would be
                                    characterized as an "excess parachute
                                    payment" to an individual who is a
                                    "disqualified individual" (as such terms are
                                    defined in Section 280G of the Code) of
                                    Security on a consolidated basis, without
                                    regard to whether such payment is reasonable
                                    compensation for personal services performed
                                    or to be performed in the future.

                  (t)      Compliance with Laws. Each of Security and the
                           Security Subsidiaries:

                           (i)      has been in compliance with all applicable
                                    federal, state, local and foreign statutes,
                                    laws, regulations, ordinances, rules,
                                    judgments, orders or decrees applicable
                                    thereto or to the employees conducting such
                                    business, including, without limitation, the
                                    Equal Credit Opportunity Act, as amended,
                                    the Fair Housing Act, as amended, the
                                    Federal Community Reinvestment Act, as
                                    amended, the Home Mortgage Disclosure Act,
                                    as amended, and all other applicable fair
                                    lending laws and other laws relating to
                                    discriminatory business practices, except
                                    for failures to be in compliance which,
                                    individually or in the aggregate, have not
                                    had or would not reasonably be expected to
                                    have a material adverse effect on Security
                                    or any Security Subsidiary;

                           (ii)     has all permits, licenses, authorizations,
                                    orders and approvals of, and has made all
                                    filings, applications and registrations
                                    with, all Governmental Authorities that are
                                    required in order to permit it to own or
                                    lease its properties and to conduct its
                                    business as presently conducted, except
                                    where the failure to obtain any of the
                                    foregoing or to make any such filing,
                                    application or registration has not had or
                                    would not reasonably be expected to have a
                                    material adverse effect on Security or any
                                    Security Subsidiary; all such permits,
                                    licenses, certificates of authority, orders
                                    and approvals are in full force and effect
                                    and to Security's knowledge, no suspension
                                    or cancellation of any of them is
                                    threatened; and

                           (iii)    has received no notification or
                                    communication from any Governmental
                                    Authority (A) asserting that Security or any
                                    Security Subsidiary is not in compliance
                                    with any of the statutes, regulations or
                                    ordinances which such Governmental Authority
                                    enforces or (B) threatening to revoke any
                                    license, franchise, permit or governmental
                                    authorization (nor, to Security's knowledge,
                                    do




                                      -23-
<PAGE>   120

                                    any reasonable grounds for any of the
                                    foregoing exist), which has not been
                                    resolved to the satisfaction of the
                                    Governmental Authority which sent such
                                    notification or communication.

                  (u)      Security Information. None of the information
                           relating to Security and the Security Subsidiaries to
                           be contained in (i) the Registration Statement (as
                           that term is defined in Section 7.08 below) will, at
                           the time the Registration Statement is filed with the
                           SEC and at the time it becomes effective under the
                           Securities Act of 1933, as amended (the "Securities
                           Act"), contain any untrue statement of a material
                           fact or omit to state a material fact required to be
                           stated therein or necessary in order to make the
                           statements therein, in light of the circumstances
                           under which they were made, not misleading, and (ii)
                           the Joint Proxy Statement (as that term is defined in
                           Section 5.03(b) below), as of the date such Joint
                           Proxy Statement is mailed to shareholders of Security
                           and up to and including the date of the meeting of
                           Security's shareholders to which such Joint Proxy
                           Statement relates, will contain any untrue statement
                           of a material fact or omit to state a material fact
                           required to be stated therein or necessary in order
                           to make the statements therein, in light of the
                           circumstances under which they were made, not
                           misleading, provided that, in each case, information
                           as of a later date shall be deemed to modify
                           information as of an earlier date. All information
                           about Security and the Security Subsidiaries included
                           in the Registration Statement and the Joint Proxy
                           Statement will be deemed to have been supplied by
                           Security.

                  (v)      Insurance.

                           (i)      Section 3.01(v) of the Security Disclosure
                                    Schedule sets forth all of the insurance
                                    policies, binders or bonds maintained by
                                    Security or any Security Subsidiary and a
                                    description of all claims filed by Security
                                    or any Security Subsidiary against the
                                    insurers of Security and the Security
                                    Subsidiaries since December 31, 1997.
                                    Security and the Security Subsidiaries are
                                    insured with reputable insurers against such
                                    risks and in such amounts as the management
                                    of Security reasonably has determined to be
                                    prudent in accordance with industry
                                    practices. All such insurance policies are
                                    in full force and effect; Security and the
                                    Security Subsidiaries are not in material
                                    default thereunder; and all claims
                                    thereunder have been filed in due and timely
                                    fashion.

                           (ii)     The savings accounts and deposits of each of
                                    Security National, Citizens National and
                                    Third Savings are insured up to applicable
                                    limits by the FDIC in accordance with the
                                    Federal Deposit Insurance Act, and each of
                                    Security National, Citizens National and
                                    Third Savings has paid all assessments and
                                    filed all reports required by the Federal
                                    Deposit Insurance Act.





                                      -24-
<PAGE>   121

                  (w)      Governmental and Third-Party Proceedings. No consent,
                           approval, authorization of, or registration,
                           declaration or filing with, any court, Governmental
                           Authority or any other third party is required to be
                           made or obtained by Security or any Security
                           Subsidiary in connection with the execution, delivery
                           or performance by Security of this Agreement or the
                           consummation by Security of the transactions
                           contemplated hereby, except for (A) filings of
                           applications and notices, as applicable, with and the
                           approval of certain federal and state banking
                           authorities, (B) filings with the SEC and state
                           securities authorities, (C) the filing of the
                           appropriate certificate of merger with the Secretary
                           of State pursuant to the OGCL, and (D) the adoption
                           of this Agreement by the Security shareholders. As of
                           the date hereof, Security is not aware of any reason
                           why the approvals set forth in Section 7.09 will not
                           be received without the imposition of a condition,
                           restriction or requirement of the type described in
                           Section 7.09.

                  (x)      Contracts. Section 3.01(x) of the Security Disclosure
                           Schedule sets forth a list, identifying by dates,
                           subject matter and parties, of all contracts,
                           agreements and instruments to which Security or any
                           Security Subsidiary is a party or by which any of
                           them is bound, and which involve the payment by or to
                           Security or any Security Subsidiary of more than
                           $50,000 in connection with the purchase of property
                           or goods or the performance of services and which are
                           not in the ordinary course of their respective
                           businesses. True, complete and correct copies of all
                           such contracts, agreements and instruments have been
                           delivered to Park. Neither Security nor any Security
                           Subsidiary, nor any other party thereto, is in
                           default under any such contract, agreement,
                           commitment, arrangement or other instrument to which
                           it is a party, by which its respective assets,
                           business or operations may be bound or affected in
                           any way, or under which it or its respective assets,
                           business or operations receive benefits, and there
                           has not occurred any event that, with the lapse of
                           time or the giving of notice or both, would
                           constitute such a default.

                  (y)      Environmental Matters. Except as otherwise disclosed
                           in Section 3.01(y) of the Security Disclosure
                           Schedule: (i) Security and the Security Subsidiaries
                           are and have been at all times in compliance in all
                           material respects with all applicable Environmental
                           Laws (as that term is defined in this Section
                           3.01(y)), and, to the knowledge of Security, neither
                           Security nor any Security Subsidiary has engaged in
                           any activity in violation of any applicable
                           Environmental Law; (ii)(A) no investigations,
                           inquiries, orders, hearings, actions or other
                           proceedings by or before any court or Governmental
                           Authority are pending or, to the knowledge of
                           Security, threatened in connection with any of
                           Security's or any Security Subsidiary's activities
                           and any Security Real Properties or improvements
                           thereon, and (B) to the knowledge of Security, no
                           investigations, inquiries, orders, hearings, actions
                           or other proceedings by or before any court or







                                      -25-
<PAGE>   122

                           Governmental Authority are pending or threatened in
                           connection with any real properties in respect of
                           which any Security Subsidiary has foreclosed or holds
                           a mortgage or mortgages (hereinafter referred to as
                           the "Security Subsidiary Real Estate Collateral");
                           (iii) no claims at any time have been made or
                           threatened by any third party against Security or any
                           Security Subsidiary, or with respect to the Security
                           Real Properties or improvements thereon, or, to the
                           knowledge of Security, the Security Subsidiary Real
                           Estate Collateral or improvements thereon, relating
                           to damage, contribution, cost recovery, compensation,
                           loss, injunctive relief, remediation or injury
                           resulting from any Hazardous Substance (as that term
                           is defined in this Section 3.01(y)) which have not
                           been resolved to the satisfaction of the involved
                           parties and which have had or are reasonably expected
                           to have a material adverse effect on Security or any
                           Security Subsidiary; (iv) no Hazardous Substances
                           have been integrated into the Security Real
                           Properties or improvements thereon or any component
                           thereof, or, to the knowledge of Security, the
                           Security Subsidiary Real Estate Collateral or
                           improvements thereon or any component thereof in such
                           manner or quantity as may reasonably be expected to
                           or in fact would pose a threat to human health or the
                           value of the real property and improvements; (v) to
                           Security's knowledge, no portion of the Security Real
                           Properties or improvements thereon, or the Security
                           Subsidiary Real Estate Collateral or improvements
                           thereon is located within 500 feet of (A) a release
                           of Hazardous Substance which has been reported or is
                           required to be reported under any Environmental Law
                           or (B) the location of any site used, in the past or
                           presently, for the disposal of any Hazardous
                           Substances; and (vi) neither Security nor any
                           Security Subsidiary has knowledge, based upon
                           commercially reasonable inquiry, that (A) any of the
                           Security Real Properties or improvements thereon, or
                           the Security Subsidiary Real Estate Collateral or
                           improvements thereon has been used for the storage or
                           disposal of Hazardous Substances or has been
                           contaminated by Hazardous Substances, (B) any of the
                           business operations of Security or any Security
                           Subsidiary have contaminated lands, waters or other
                           property of others with Hazardous Substances, except
                           routine, office-generated solid waste, or (C) any of
                           the Security Real Properties or improvements thereon,
                           or the Security Subsidiary Real Estate Collateral or
                           improvements thereon have in the past or presently
                           contain underground storage tanks, friable asbestos
                           materials or PCB-containing equipment.

                           For purposes of this Agreement, (i) "Environmental
                           Law" means the Comprehensive Environmental Response,
                           Compensation and Liability Act of 1980, as amended
                           ("CERCLA"); the Resource Conservation and Recovery
                           Act of 1976, as amended; the Hazardous Materials
                           Transportation Act, as amended; the Toxic Substances
                           Control Act, as amended; the Federal Water Pollution
                           Control Act, as amended; the Safe Drinking Water Act,
                           as amended; the Clean Air Act, as amended; the







                                      -26-
<PAGE>   123

                           Occupational Safety and Health Act of 1970, as
                           amended; the Hazardous & Solid Waste Amendments Act
                           of 1984, as amended; the Superfund Amendments and
                           Reauthorization Act of 1986, as amended; the
                           regulations promulgated thereunder, and any other
                           federal, state, county, municipal, local or other
                           statute, law, ordinance or regulation which may
                           relate to or deal with human health or the
                           environment, as of the date of this Agreement, and
                           (ii) "Hazardous Substances" means, at any time: (a)
                           any "hazardous substance" as defined in sec. 101(14)
                           of CERCLA or regulations promulgated thereunder; (b)
                           any "solid waste," "hazardous waste," or "infectious
                           waste," as such terms are defined in any other
                           Environmental Law as of the date of this Agreement;
                           and (c) friable asbestos, urea-formaldehyde,
                           polychlorinated biphenyls ("PCBs"), nuclear fuel or
                           material, chemical waste, radioactive material,
                           explosives, known carcinogens, petroleum products and
                           by-products, and other dangerous, toxic or hazardous
                           pollutants, contaminants, chemicals, materials or
                           substances listed or identified in, or regulated by,
                           any Environmental Law.

                  (z)      Pooling. Neither Security nor any Security Subsidiary
                           has taken, permitted or agreed to take any action
                           that would prevent Park from accounting for the
                           business combination to be effected by the Merger as
                           a "pooling-of-interests."

                  (aa)     Takeover Laws. Security has taken all action required
                           to be taken by it in order to exempt this Agreement
                           and the transactions contemplated hereby from, and
                           this Agreement and the transactions contemplated
                           hereby are exempt from, the requirements of any
                           "moratorium", "control share", "fair price",
                           "affiliate transaction", "business combination" or
                           other anti-takeover laws or regulations of any state
                           (collectively, "Takeover Laws") applicable to it,
                           including, without limitation, those of the State of
                           Ohio.

                  (bb)     Risk Management Instruments. All material interest
                           rate swaps, caps, floors, option agreements, futures
                           and forward contracts and other similar risk
                           management arrangements, whether entered into for
                           Security's own account, or for the account of one or
                           more of the Security Subsidiaries or any of their
                           respective customers (all of which are listed on the
                           Security Disclosure Schedule), were entered into (i)
                           in accordance with prudent business practices and all
                           applicable laws, rules, regulations and regulatory
                           policies and (ii) with counter-parties believed to be
                           financially responsible at the time; and each of them
                           constitutes the valid and legally binding obligation
                           of Security or the applicable Security Subsidiary,
                           enforceable in accordance with its terms, and is in
                           full force and effect. Neither Security nor any
                           Security Subsidiary, nor to Security's knowledge any
                           other party thereto, is in breach of any of its
                           obligations under any such agreement or arrangement.





                                      -27-
<PAGE>   124

                  (cc)     Books and Records. The books and records of Security
                           and the Security Subsidiaries have been fully,
                           properly and accurately maintained and have been
                           maintained in accordance with sound business
                           practices. Such books and records fairly reflect the
                           substance of events and transactions included
                           therein.

                  (ee)     Repurchase Agreements. With respect to any agreement
                           pursuant to which Security or any Security Subsidiary
                           has purchased securities subject to an agreement to
                           repurchase, Security or the relevant Security
                           Subsidiary, as the case may be, has a valid,
                           perfected first lien or security interest in or
                           evidence of ownership in book entry form of the
                           government securities or other collateral securing
                           the repurchase agreement, and the value of such
                           collateral equals or exceeds the amount of the debt
                           secured thereby.

                  (ff)     Disclosure. No representation or warranty by Security
                           contained in this Agreement and no statement
                           contained in any certificate or other document
                           (including the Security Disclosure Schedule and any
                           letter furnished by Security as contemplated by
                           Sections 8.01(d) and 8.02(c) of this Agreement)
                           furnished by Security to Park pursuant to this
                           Agreement contains any untrue statement of a material
                           fact or omits to state a material fact necessary to
                           make the statements contained herein and therein not
                           misleading, in the light of the circumstances under
                           which they were made.

                  (gg)     Investment Securities. Each of Security and the
                           Security Subsidiaries has good and marketable title
                           to all securities held by it (except securities sold
                           under repurchase agreement or held in any fiduciary
                           or agency capacity), free and clear of any charge,
                           mortgage, pledge, security interest, hypothecation,
                           restriction, claim, option, lien, encumbrance or
                           interest of any person or persons whatsoever, except
                           to the extent such securities are pledged in the
                           ordinary course of business consistent with prudent
                           banking practice to secure obligations of Security or
                           any Security Subsidiary. Such securities are valued
                           on the books of Security in accordance with GAAP.

                  (hh)     SEC Filings. The Security Shares are registered with
                           the SEC pursuant to Section 12(g) of the Securities
                           Exchange Act of 1934, as amended (the "Exchange
                           Act"). Security has filed all reports and proxy
                           materials required to be filed by it with the SEC
                           pursuant to the Exchange Act, except for any reports
                           or proxy materials the failure to file which would
                           not have a material adverse effect upon Security and
                           the Security Subsidiaries taken as a whole. All such
                           filings, at the time of filing, complied in all
                           material respects as to form and included all
                           exhibits required to be filed under the applicable
                           rules of the SEC. None of such documents, when filed,
                           contained any untrue statement of a material fact or
                           omitted to state a material fact required to be
                           stated therein or necessary in





                                      -28-
<PAGE>   125

                           order to make the statements therein, in light of the
                           circumstances under which they were made, not
                           misleading.

                  (ii)     Fiduciary Responsibilities. During the applicable
                           statute of limitations period, (i) each Security
                           Subsidiary has properly administered all accounts (if
                           any) 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 investor
                           advisor, in accordance with the terms of the
                           governing documents and applicable state and federal
                           law and regulation and common law, and (ii) neither
                           any Security Subsidiary nor any Director, Officer or
                           Employee of a Security Subsidiary acting on behalf of
                           such Security Subsidiary has committed any breach of
                           trust with respect to any such fiduciary or agency
                           account, and the accountings of each such fiduciary
                           or agency account are true and correct and accurately
                           reflect the assets of such fiduciary or agency
                           account. To the knowledge of Security, there is no
                           investigation or inquiry by any regulatory Authority
                           pending or threatened against or affecting any
                           Security Subsidiary relating to the compliance by
                           such Security Subsidiary with sound fiduciary
                           principles and applicable regulations.

                  (jj)     CRA Compliance. Neither Security nor any Security
                           Subsidiary has received any notice of non-compliance
                           with the applicable provisions of the Federal
                           Community Reinvestment Act, as amended ("CRA"), and
                           the regulations promulgated thereunder, and each of
                           Security National, Citizens National and Third
                           Savings has received a CRA rating of satisfactory or
                           better from the OCC or the OTS, as appropriate.
                           Security knows of no fact or circumstance or set of
                           facts or circumstances which would cause Security or
                           any Security Subsidiary to receive any notice of
                           non-compliance with such provisions or cause the CRA
                           rating of Security or any Security Subsidiary to fall
                           below satisfactory.

                  (kk)     Ownership of Park Shares. As of the date hereof,
                           except as otherwise disclosed in Section 3.01(kk) of
                           the Security Disclosure Schedule, neither Security
                           nor, to the knowledge of Security, any of its
                           affiliates or associates (as such terms are defined
                           under the Exchange Act), (i) beneficially owns,
                           directly or indirectly, or (ii) is a party to any
                           agreement, arrangement or understanding for the
                           purpose of acquiring, holding, voting or disposing
                           of, any Park Shares.

                  (ll)     The Board of Directors of Security has received an
                           opinion of Austin Associates, Inc. dated the date of
                           this Agreement to the effect that the consideration
                           to be received by the Security shareholders in the
                           Merger is fair, from a financial point of view, to
                           the Security shareholders.










                                      -29-

<PAGE>   126

                                  ARTICLE FOUR
                     REPRESENTATIONS AND WARRANTIES OF PARK

                  4.01.    REPRESENTATIONS AND WARRANTIES OF PARK

                  Park hereby warrants and represents to Security that:

                  (a)      Corporate Status. Park is an Ohio corporation and a
                           bank holding company registered under the BHC Act; is
                           duly organized, validly existing and in good standing
                           under the laws of the State of Ohio; and has the full
                           corporate power and authority to own its property, to
                           carry on its business as presently conducted and to
                           enter into and, subject to the required adoption of
                           this Agreement by the Park shareholders and the
                           obtaining of appropriate approvals of Governmental
                           Authorities and Regulatory Authorities, perform its
                           obligations under this Agreement and consummate the
                           transactions contemplated by this Agreement.

                  (b)      Corporate Proceedings. All corporate proceedings of
                           Park necessary to authorize the execution, delivery
                           and performance of this Agreement, and the
                           consummation of the transactions contemplated by this
                           Agreement, in each case by Park, have been duly and
                           validly taken, except for the adoption of this
                           Agreement by the holders of two-thirds of the
                           outstanding Park Shares entitled to vote thereon
                           (which is the only required shareholder vote
                           thereon). This Agreement has been validly executed
                           and delivered by duly authorized officers of Park.

                  (c)      Capitalization of Park.

                           (i)      As of the date of this Agreement, the
                                    authorized capital stock of Park consists
                                    only of 20,000,000 common shares, without
                                    par value, of which 10,798,043 Park Shares
                                    are issued and outstanding and 393,686 Park
                                    Shares are held in treasury by Park. The
                                    outstanding Park Shares have been duly
                                    authorized and are validly issued, fully
                                    paid and non-assessable, and were not issued
                                    in violation of the preemptive rights of any
                                    person. As of the date of this Agreement,
                                    307,978 Park Shares were reserved for
                                    issuance upon the exercise of outstanding
                                    incentive stock options granted under the
                                    Park National Corporation 1995 Incentive
                                    Stock Option Plan (the "Park Stock Option
                                    Plan") and 326,551 Park Shares were
                                    available for future grants of incentive
                                    stock options under the Park Stock Option
                                    Plan. As of the date of this Agreement,
                                    except for the Merger Shares issuable
                                    pursuant to this Agreement, Park has no
                                    other commitment or obligation to issue,
                                    deliver or sell any Park Shares.



                                      -30-
<PAGE>   127


                           (ii)     The Park Shares to be issued in exchange for
                                    Security Shares in the Merger, when issued
                                    in accordance with the terms of this
                                    Agreement, will be duly authorized, validly
                                    issued, fully paid and non-assessable and
                                    subject to no preemptive rights.

                  (d)      Authorized and Effective Agreement. This Agreement
                           constitutes the legal, valid and binding obligation
                           of Park, enforceable against Park in accordance with
                           its terms, except as the same may be limited by
                           bankruptcy, insolvency, reorganization, moratorium,
                           fraudulent conveyance and other similar laws relating
                           to or affecting the enforcement of creditors' right
                           generally, by general equitable principles
                           (regardless of whether enforceability is considered
                           in a proceeding in equity or at law) and by an
                           implied covenant of good faith and fair dealing. Park
                           has the absolute and unrestricted right, power,
                           authority and capacity to execute and deliver this
                           Agreement and, subject to the required adoption of
                           this Agreement by the Park shareholders, satisfaction
                           of the requirements referred to in Section 4.01(k),
                           the expiration of applicable regulatory waiting
                           periods, and required filings under federal and state
                           securities laws, to perform its obligations under
                           this Agreement.

                  (e)      No Conflict. Subject to the required adoption of this
                           Agreement by Park's shareholders, the satisfaction of
                           the requirements referred to in Section 4.01(k), the
                           expiration of applicable regulatory waiting periods,
                           and required filings under federal and state
                           securities laws, the execution, delivery and
                           performance of this Agreement, and the consummation
                           of the transactions contemplated by this Agreement,
                           by Park do not and will not (i) conflict with, or
                           result in a violation of, or result in the breach of
                           or a default (or which with notice or lapse of time
                           would result in a default) under, any provision of:
                           (A) any federal, state or local law, regulation,
                           ordinance, order, rule or administrative ruling of
                           any Governmental Authority applicable to Park or any
                           of its properties; (B) the Articles of Incorporation
                           or Regulations of Park; (C) any material agreement,
                           indenture or instrument to which Park is a party or
                           by which it or its properties or assets may be bound;
                           or (D) any order, judgment, writ, injunction or
                           decree of any court, arbitration panel or any
                           Governmental Authority applicable to Park; (ii)
                           result in the creation or acceleration of any
                           security interest, mortgage, option, claim, lien,
                           charge or encumbrance upon or interest in any
                           property of Park; or (iii) violate the terms or
                           conditions of, or result in the cancellation,
                           modification, revocation or suspension of, any
                           material license, approval, certificate, permit or
                           authorization held by Park.

                  (f)      Financial Statements of Park. Park has furnished to
                           Security consolidated financial statements of Park
                           consisting of (i) consolidated balance sheets as of
                           December 31, 1999 and 1998 and the related
                           consolidated statements of income, changes in
                           shareholders' equity and cash flows for the three



                                      -31-
<PAGE>   128


                           years ended December 31, 1999, including accompanying
                           notes and the report thereon of Ernst & Young LLP and
                           (ii) unaudited consolidated balance sheet as of
                           September 30, 2000 (the "Park Balance Sheet Date"),
                           the related unaudited consolidated statements of
                           income for the three and nine months ended September
                           30, 2000 and 1999, of changes in shareholders' equity
                           for the nine months ended September 30, 2000 and 1999
                           and of cash flows for the nine months ended September
                           30, 2000 and 1999 (collectively, all of such
                           consolidated financial statements are referred to as
                           the "Park Financial Statements"). The Park Financial
                           Statements were prepared in conformity with GAAP
                           applied on a consistent basis and present fairly, in
                           all material respects, the consolidated financial
                           condition of Park at the dates, and the consolidated
                           results of operations and cash flows for the periods,
                           stated therein; subject, in the case of the interim
                           financial statements, to normal year-end audit
                           adjustments which are not expected to be,
                           individually or in the aggregate, materially adverse
                           to Park and the absence of full footnotes.

                  (g)      Absence of Changes. Since the Park Balance Sheet
                           Date: (i) the businesses of Park and its Subsidiaries
                           have been conducted only in the ordinary course
                           consistent with past practice; (ii) there has been no
                           material adverse change in the assets, liabilities,
                           business or operations of Park and its Subsidiaries
                           taken as a whole; and (iii) there has been no damage,
                           destruction, loss or event (whether or not insured
                           against) which in the aggregate has had or might
                           reasonably be expected to have a material adverse
                           effect on the business or operations of Park and its
                           Subsidiaries taken as a whole.

                  (h)      Takeover Laws. Park has taken all action required to
                           be taken by it in order to exempt this Agreement and
                           the transactions contemplated hereby from, and this
                           Agreement and the transactions contemplated hereby
                           are exempt from, the requirements of any Takeover
                           Laws applicable to Park.

                  (i)      SEC Filings. The Park Shares are registered with the
                           SEC pursuant to Section 12(b) of the Exchange Act.
                           Park has filed all reports and proxy materials
                           required to be filed by it with the SEC pursuant to
                           the Exchange Act, except for any reports or proxy
                           materials the failure to file which would not have a
                           material adverse effect upon Park and its
                           Subsidiaries taken as a whole. All such filings, at
                           the time of filing, complied in all material respects
                           as to form and included all exhibits required to be
                           filed under the applicable rules of the SEC. None of
                           such documents, when filed, contained any untrue
                           statement of a material fact or omitted to state a
                           material fact required to be stated therein or
                           necessary in order to make the statements therein, in
                           light of the circumstances under which they were
                           made, not misleading.


                                      -32-
<PAGE>   129



                  (j)      Brokers, Finders and Others. There are no fees or
                           commissions of any sort whatsoever claimed by, or
                           payable by Park to, any broker, finder, intermediary
                           or any other similar person in connection with
                           effecting this Agreement or the transactions
                           contemplated hereby.

                  (k)      Governmental and Third-Party Proceedings. No consent,
                           approval, authorization of, or registration,
                           declaration or filing with, any court, Governmental
                           Authority or any other third party is required to be
                           made or obtained by Park in connection with the
                           execution, delivery or performance by Park of this
                           Agreement or the consummation by Park of the
                           transactions contemplated hereby, except for (A)
                           filings of applications or notices, as applicable,
                           with and the approval of certain federal and state
                           banking authorities, (B) filings with the SEC and
                           state securities authorities, (C) the adoption of
                           this Agreement by the Park shareholders, (D) the
                           filing of the appropriate certificate of merger with
                           the Secretary of State pursuant to the OGCL and (E)
                           receipt of the approvals set forth in Section 7.09.
                           As of the date hereof, Park is not aware of any
                           reason why the approvals set forth in Section 7.09
                           will not be received without the imposition of a
                           condition, restriction or requirement of the type
                           described in Section 7.09.

                  (l)      Pooling. Neither Park nor any of its Subsidiaries has
                           taken or permitted any action which would prevent the
                           Merger from being accounted for as a
                           "pooling-of-interests."

                  (m)      Park Information. None of the information relating to
                           Park and its Subsidiaries to be contained in (i) the
                           Registration Statement will, at the time the
                           Registration Statement is filed with the SEC and at
                           the time it becomes effective under the Securities
                           Act, contain any untrue statement of a material fact
                           or omit to state a material fact required to be
                           stated therein or necessary in order to make the
                           statements therein, in light of the circumstances
                           under which they were made, not misleading, and (ii)
                           the Joint Proxy Statement, as of the date such Joint
                           Proxy Statement is mailed to shareholders of Park and
                           up to and including the date of the meeting of the
                           Park shareholders to which such Joint Proxy Statement
                           relates, will contain any untrue statement of a
                           material fact or omit to state a material fact
                           required to be stated therein or necessary in order
                           to make the statements therein, in light of the
                           circumstances under which they were made, not
                           misleading, provided that, in each case, information
                           as of a later date shall be deemed to modify
                           information as of an earlier date. All information
                           about Park and its Subsidiaries included in the
                           Registration and the Joint Proxy Statement will be
                           deemed to have been supplied by Park.

                  (n)      Deposit Insurance. The deposits of Park's bank
                           Subsidiaries are insured by the FDIC in accordance
                           with the Federal Deposit Insurance Act and



                                      -33-
<PAGE>   130


                           said bank Subsidiaries have paid all assessments and
                           filed all reports required by the Federal Deposit
                           Insurance Act.

                  (o)      Disclosure. No representation or warranty by Park
                           contained in this Agreement, and no statement
                           contained in any certificate or other document
                           (including any letter furnished by Park as
                           contemplated by Sections 8.01(d) and 8.02(c) of this
                           Agreement) furnished by Park to Security pursuant to
                           this Agreement contains any untrue statement of a
                           material fact or omits to state a material fact
                           necessary to make the statements contained herein and
                           therein not misleading, in the light of the
                           circumstances under which they were made.

                  (p)      Ownership of Security Shares. As of the date hereof,
                           other than 15,000 Security Shares beneficially owned
                           directly by Park, neither Park nor any of its
                           Subsidiaries (i) beneficially owns, directly or
                           indirectly, or (ii) is a party to any agreement,
                           arrangement or understanding for the purpose of
                           acquiring, holding, voting or disposing of, any
                           Security Shares.

                                  ARTICLE FIVE
                          FURTHER COVENANTS OF SECURITY

                  5.01.    OPERATION OF BUSINESS

                  Security covenants with Park that throughout the period from
the date of this Agreement to and including the Closing:

                  (a)      Conduct of Business. Security's business, and the
                           business of each Security Subsidiary, will be
                           conducted only in the ordinary and usual course
                           consistent with past practice. Without the written
                           consent of Park, Security shall not, and shall cause
                           each Security Subsidiary not to (i) take any action
                           which would be inconsistent with any representation
                           or warranty of Security set forth in this Agreement
                           or which would cause a breach of any such
                           representation or warranty if made at or immediately
                           following such action; or (ii) engage in any lending
                           activities other than in the ordinary course of
                           business consistent with past practice. To the extent
                           permitted under applicable law or regulation,
                           Security shall send to Park via facsimile
                           transmission a copy of all loan presentations made to
                           the Board of Directors of Security at the same time
                           as such presentations are transmitted to such Board
                           and all other proposals for loans in excess of
                           $500,000. Security shall consult with Park prior to
                           (x) hiring any full-time officer, other than
                           replacement employees for positions then existing;
                           and (y) purchasing any investment securities.

                  (b)      Changes in Business and Capital Structure. Except as
                           provided for by this Agreement, set forth in the
                           Security Disclosure Letter or as otherwise



                                      -34-
<PAGE>   131


                           approved expressly in writing by Park (which approval
                           will not be unreasonably withheld or delayed),
                           Security will not, and will cause each Security
                           Subsidiary not to:

                           (i)      sell, transfer, mortgage, pledge or subject
                                    to any lien or otherwise encumber any of the
                                    assets of Security or the Security
                                    Subsidiary, tangible or intangible, except
                                    in the ordinary course of business for full
                                    and fair consideration actually received;

                           (ii)     make any capital expenditure or capital
                                    additions or betterments which individually
                                    exceed $100,000;

                           (iii)    become bound by, enter into, or perform any
                                    material contract, commitment or transaction
                                    which is other than in the ordinary course
                                    of its business or which would cause or
                                    result in its being unable to perform its
                                    obligations under this Agreement;

                           (iv)     declare, pay or set aside for payment any
                                    dividends or make any distributions on its
                                    capital shares issued and outstanding other
                                    than quarterly cash dividends on Security
                                    Shares in respect of fiscal quarters ending
                                    on or after December 31, 2000 in an amount
                                    not to exceed $0.20 per share, in each case
                                    with record and payment dates as indicated
                                    in Section 7.10 of this Agreement;

                           (v)      purchase, redeem, retire or otherwise
                                    acquire any of its capital shares;

                           (vi)     issue or grant any option or right to
                                    acquire any of its capital shares or any
                                    Voting Debt or effect, directly or
                                    indirectly, any share split,
                                    recapitalization, combination, exchange of
                                    shares, readjustment or other
                                    reclassification;

                           (vii)    amend its articles of incorporation,
                                    constitution, articles of association,
                                    regulations, by-laws or other governing
                                    documents;

                           (viii)   merge or consolidate with any other person
                                    or otherwise reorganize except for the
                                    Merger;

                           (ix)     acquire (other than by way of foreclosures
                                    or acquisitions of control in a bona fide
                                    fiduciary capacity or in satisfaction of
                                    debts previously contracted in good faith,
                                    in each case in the ordinary and usual
                                    course of business consistent with past
                                    practice) all or any portion of, the assets,
                                    business, deposits or properties of any
                                    other entity;

                           (x)      enter into, establish, adopt or amend any
                                    pension, retirement, stock option, stock
                                    purchase, savings, profit-sharing, deferred
                                    compensa-



                                      -35-
<PAGE>   132


                                    tion, consulting, bonus, group insurance or
                                    other employee benefit, incentive or welfare
                                    contract, plan or arrangement, or any trust
                                    agreement (or similar arrangement) related
                                    thereto, in respect of any Director, Officer
                                    or Employee of Security or any Security
                                    Subsidiary, or take any action to accelerate
                                    the vesting or exercisability of stock
                                    options, restricted stock or other
                                    compensation or benefits payable thereunder;
                                    provided, however, that Security may (A)
                                    take such actions in order to satisfy either
                                    applicable law or contractual obligations
                                    existing as of the date hereof and disclosed
                                    in the Security Disclosure Schedule or
                                    regular annual renewals of insurance
                                    contracts; and (B) terminate its defined
                                    contribution retirement plan at any time
                                    before the Effective Time, with benefit
                                    distributions deferred until the IRS issues
                                    a favorable determination with respect to
                                    the terminating plan's tax-qualified status
                                    upon termination and with Security and Park
                                    to cooperate in good faith to apply for such
                                    approval and to agree upon associated plan
                                    termination amendments that shall, among
                                    other things, provide for the application of
                                    all assets of a terminating plan for its
                                    participants, and allow plan participants
                                    not only to receive lump-sum distributions
                                    of their benefits but also to transfer those
                                    benefits to the Park National Corporation
                                    Employee's Voluntary Salary Deferral Plan
                                    and Trust maintained for employees of Park
                                    and its Subsidiaries;

                           (xi)     pay any general wage or salary increase or
                                    bonus, other than normal pay increases and
                                    bonuses consistent with past practices, or
                                    enter into or amend or renew any employment,
                                    consulting, severance or similar agreements
                                    or arrangements with any Officer, Director
                                    or Employee, except, in each case, for
                                    changes which are required by applicable law
                                    or to satisfy contractual obligations
                                    existing as of the date hereof and disclosed
                                    in the Security Disclosure Schedule;

                           (xii)    enter into or terminate any contract, other
                                    than a loan contract, requiring the payment
                                    or receipt of $100,000 or more in any
                                    12-month period or amend or modify in any
                                    material respect any of its existing
                                    material contracts;

                           (xiii)   incur any indebtedness for money borrowed or
                                    incur any material obligation or liability
                                    other than in the ordinary course of
                                    business;

                           (xiv)    take any action that would, or is reasonably
                                    likely to, prevent or impede the Merger from
                                    qualifying (A) for "pooling-of-interests"
                                    accounting treatment or (B) as a
                                    reorganization within the meaning of Section
                                    368(a) of the Code;



                                      -36-
<PAGE>   133



                           (xv)     implement or adopt any change in its
                                    accounting principles, practices or methods,
                                    other than as may be required by GAAP;

                           (xvi)    waive or cancel any right of material value
                                    or material debts, except in the ordinary
                                    course of business consistent with past
                                    practices;

                           (xvii)   take any action that would result in (A) any
                                    of its representations or warranties
                                    contained in this Agreement being or
                                    becoming untrue in any material respect at
                                    any time at or prior to the Effective Time,
                                    (B) any of the conditions to the Merger set
                                    forth in Article Eight not being satisfied
                                    or (C) a violation of any provision of this
                                    Agreement except, in each case, as may be
                                    required by applicable law or regulation;

                           (xviii)  cause any material adverse change in the
                                    amount or general composition of deposit
                                    liabilities;

                           (xix)    make any material investment (except in the
                                    ordinary course of business); or

                           (xx)     enter into any agreement to do any of the
                                    foregoing.

                  (c)      Maintenance of Property. Security and the Security
                           Subsidiaries will use their commercially reasonable
                           efforts to maintain and keep their respective
                           properties and facilities in their present condition
                           and working order, ordinary wear and tear excepted.

                  (d)      Performance of Obligations. Security and the Security
                           Subsidiaries will perform all of their obligations
                           under all agreements relating to or affecting their
                           respective properties, rights and businesses, except
                           where nonperformance would not have a material
                           adverse effect on Security or any Security
                           Subsidiary.

                  (e)      Maintenance of Business Organization. Security will,
                           and will cause the Security Subsidiaries to, use
                           their commercially reasonable efforts to maintain and
                           preserve their respective business organizations
                           intact; to retain present key Employees; and to
                           maintain the respective relationships of customers,
                           suppliers and others having business relationships
                           with them. Security will not, and will cause the
                           Security Subsidiaries not to, take any action or omit
                           to take any action which would terminate or enable
                           any Employee of Security or any Security Subsidiary
                           to terminate his employment or employment agreement
                           without cause and continue thereafter to receive
                           compensation.

                  (f)      Insurance. Security and the Security Subsidiaries
                           will maintain insurance coverage with reputable
                           insurers, which in respect of amounts, premiums,



                                      -37-
<PAGE>   134


                           types and risks insured, were maintained by them at
                           the Security Balance Sheet Date, and upon the renewal
                           or termination of such insurance, Security and the
                           Security Subsidiaries will use commercially
                           reasonable best efforts to renew or replace such
                           insurance coverage with reputable insurers, in
                           respect of the amounts, premiums, types and risks
                           insured or maintained by them at the Balance Sheet
                           Date.

                  (g)      Access to Information. Security will, and will cause
                           the Security Subsidiaries to, take all action
                           necessary to (i) afford the officers and designated
                           representatives of Park full access during normal
                           business hours upon reasonable notice to all of
                           Security's and each Security Subsidiary's respective
                           properties and, to the extent Security or any
                           Security Subsidiary has or may provide such access,
                           to the Security Subsidiary Real Estate Collateral
                           (including for purposes of inspection and
                           investigation for soil and groundwater tests), books,
                           records, Tax Returns and reports, financial
                           statements, contracts and commitments, and any work
                           papers relating to any of the foregoing; (ii) furnish
                           to Park any and all documents, copies of documents,
                           and information (A) concerning compliance and/or
                           noncompliance with Environmental Laws and with
                           respect to the past, present or suspected future
                           presence of Hazardous Substances on the Security Real
                           Properties and the Security Subsidiary Real Estate
                           Collateral, including but not limited to
                           environmental audit and Phase I reports, and (B)
                           concerning Security's and each Security Subsidiary's
                           affairs as Park may reasonably request; (iii) afford
                           full access to Park to Security's and each Security
                           Subsidiary's Officers, Directors, Employees and
                           agents in order that Park may have full opportunity
                           to make such investigation as it shall desire to make
                           of the business and affairs of Security and the
                           Security Subsidiaries; and (iv) authorize Park's
                           representatives to inquire of government agencies,
                           and inspect the files of those agencies, with respect
                           to the environment conditions on and about the
                           Security Real Properties and the Security Subsidiary
                           Real Estate Collateral. During the period from the
                           date of this Agreement to the Effective Time,
                           Security shall promptly furnish Park with copies of
                           all monthly and other interim financial statements
                           produced in the ordinary course of business as the
                           same shall become available.

                  (h)      Payment of Taxes. Security shall, and shall cause
                           Security Subsidiaries to, timely file all Tax Returns
                           required to be filed on or before the Closing Date,
                           and pay any Tax shown on such Tax Returns to be due.

                  (i)      Risk Management. Except as required by applicable law
                           or regulation, neither Security nor any Security
                           Subsidiary shall (i) implement or adopt any material
                           change in its interest rate risk management and other
                           risk management policies, procedures or practices;
                           (ii) fail to follow its existing policies or
                           practices with respect to managing its exposure to
                           interest rate and other risks; or (iii) fail to use
                           commercially reasonable



                                      -38-
<PAGE>   135


                           means to avoid any material increase in its aggregate
                           exposure to interest rate risk.

                  5.02.    NOTIFICATION

                  Between the date of this Agreement and the Closing Date,
Security will promptly notify Park in writing if Security becomes aware of any
fact or condition that (a) causes or constitutes a breach of any of Security's
representations and warranties or (b) would (except as expressly contemplated by
this Agreement) cause or constitute a breach of any such representation or
warranty had such representation or warranty been made as of the time of
occurrence or discovery of such fact or condition. Should any such fact or
condition require any change in the Security Disclosure Schedule, Security will
promptly deliver to Park a supplement to the Security Disclosure Schedule
specifying such change ("Updated Security Disclosure Schedule"). During the same
period, Security will promptly notify Park of (i) the occurrence of any breach
of any of Security's covenants contained in this Agreement, (ii) the occurrence
of any event that may make the satisfaction of the conditions in this Agreement
impossible or unlikely or (iii) the occurrence of any event that is reasonably
likely, individually or taken with all other facts, events or circumstances
known to Security, to result in a material adverse effect with respect to
Security. In addition, if at any time prior to the Effective Time, any event or
circumstance relating to Security or any of its Officers or Directors should be
discovered which should be set forth in an amendment to the Registration
Statement or a supplement to the Joint Proxy Statement, Security shall promptly
inform Park.

                  5.03.    SHAREHOLDER APPROVAL

                  Security covenants that:

                  (a)      The Board of Directors of Security will recommend the
                           adoption of this Agreement and the approval of the
                           transactions contemplated hereby to the shareholders
                           of Security, subject to that Board's fiduciary
                           obligations under Ohio law, as determined in good
                           faith after consultation with and based upon advise
                           of independent legal counsel.

                  (b)      Security will call a meeting of its shareholders (the
                           "Security Meeting") to be held as soon as reasonably
                           practicable after the Registration Statement is
                           declared effective by the SEC, for the purpose of
                           adopting this Agreement and approving the
                           transactions contemplated hereby and will, subject to
                           the provisions of Sections 5.03(a) and 5.04, use its
                           best efforts to effect such adoption and approval.
                           Security will prepare appropriate proxy solicitation
                           materials in respect of the Security Meeting, which
                           materials will include the joint proxy statement of
                           Security and Park (the "Joint Proxy Statement") and
                           which will be a part of the Registration Statement to
                           be submitted by Park to the SEC pursuant to Section
                           7.08 of this Agreement.


                                      -39-
<PAGE>   136


                  5.04.    ACQUISITION PROPOSALS

                  From and after the date hereof, Security will not, directly or
indirectly, through any of its Officers, Directors, Employees, agents or
advisors, (i) solicit or initiate or knowingly encourage, including by means of
furnishing information, any proposals, offers or inquiries from any person
relating to any acquisition or purchase of 20% or more of the outstanding shares
of any class of voting securities of, or 20% or more of the assets or deposits
of, Security or any Security Subsidiary, or any merger, tender or exchange
offer, consolidation or business combination involving, Security or any Security
Subsidiary (an "Acquisition Proposal") or (ii) unless the Board of directors of
Security determines in good faith that such action is required for that Board to
fulfill the Board's fiduciary duties and obligations to the Security
shareholders under Ohio law as advised by counsel to Security and Security gives
prior notice to Park of such action (in which event Security may furnish
information), engage in negotiations with or disclose any nonpublic information
relating to Security or any Security Subsidiary or afford access to the Security
Real Properties, or the books or records of Security or any Security Subsidiary
to any person that may be considering or has made an Acquisition Proposal.
Security shall promptly (within 24 hours) notify Park, orally and in writing, if
any such proposal, offer, inquiry or contact is made and shall, in any such
notice, indicate the identity and terms and conditions of any proposal or offer,
or any such inquiry or contact. Security shall immediately cease and cause to be
terminated any activities, discussions or negotiations conducted prior to the
date of this Agreement with any parties other than Park with respect to any
Acquisition Proposal and shall use its reasonable best efforts to enforce any
confidentiality or similar agreement relating to an Acquisition Proposal.

                  5.05.    DELIVERY OF INFORMATION

                  (a)      Security will promptly furnish to Park all
                           information requested by Park regarding Security's
                           assets, properties, business, affairs, operations,
                           condition (financial or otherwise), prospects and
                           corporate organization as shall be required by the
                           rules and regulations under the Securities Act or by
                           the SEC for inclusion in the Registration Statement
                           described in Section 7.08 and shall otherwise
                           reasonably assist Park in the preparation and filing
                           of such Registration Statement.

                  (b)      Security shall furnish to Park promptly after such
                           documents are available: (i) all reports, proxy
                           statements or other communications by Security to its
                           shareholders generally; and (ii) all press releases
                           relating to any transactions.

                  5.06.    AFFILIATES COMPLIANCE WITH THE SECURITIES ACT

                  (a)      In the Security Disclosure Schedule and no later than
                           the 15th day prior to the mailing of the Security
                           Proxy Statement, Security shall deliver to Park a
                           schedule of all persons whom Security reasonably
                           believes are, or are likely to be, as of the date of
                           the Security Meeting, deemed to be "affiliates" of
                           Security as that term is used in Rule 145 under the



                                      -40-
<PAGE>   137


                           Securities Act and/or Accounting Series Releases 130
                           and 135, as amended, of the SEC (the "Rule 145
                           Affiliates"). Thereafter and until the Effective
                           Time, Security shall identify to Park each additional
                           person whom Security reasonably believes to have
                           thereafter become a Rule 145 Affiliate.

                  (b)      Security shall use its diligent efforts to cause each
                           person who is identified as a Rule 145 Affiliate
                           pursuant to Section 5.06(a) above (who has not
                           executed and delivered the same concurrently with the
                           execution of this Agreement) to execute and deliver
                           to Park on or before the date of mailing of the Joint
                           Proxy Statement, a written agreement, substantially
                           in the form of Exhibit A attached hereto. Because the
                           Merger is intended to qualify for
                           "pooling-of-interests" accounting treatment, the Park
                           Shares received by such Rule 145 Affiliates in the
                           Merger shall not be transferable for a period
                           beginning 30 days before the Effective Time and
                           ending on such date as financial results covering at
                           least 30 days of post-Merger operations have been
                           published within the meaning of Section 201.01 of the
                           SEC's Codification of Financial Reporting Policies,
                           regardless of whether each such Rule 145 Affiliate
                           has provided the written agreement referred to in
                           this Section, and the certificates representing such
                           Park Shares will bear an appropriate restrictive
                           legend.

                  5.07.    TAKEOVER LAWS

                  Security shall take all necessary steps to (a) exempt (or
cause the continued exemption of) this Agreement and the Merger from the
requirements of any Takeover Law and from any provisions under its articles of
incorporation and regulations, as applicable, by action of the Board of
Directors of Security or otherwise, and (b) assist in any challenge by Park to
the validity, or applicability to the Merger, of any Takeover Law.

                  5.08.    TITLE INSURANCE

                  For each parcel of Security Real Property as to which Park may
specifically request, Security shall deliver to Park, and Park shall pay for, a
title insurance commitment (ALTA Form B-1992 or its equivalent) for a fee
owner's title insurance policy or leasehold owner's title insurance policy, as
appropriate, each in an amount equal to the carrying cost of the premises or
leasehold interest to be insured (including all improvements thereon), on the
books of Security or the applicable Security Subsidiary. Each title insurance
commitment shall show that marketable fee simple title to the owned premises or
that valid leasehold title to the leased premises, as appropriate, is in the
name of Security or a Security Subsidiary, and that the premises is free and
clear of any liens and encumbrances except taxes and assessments not delinquent
and utility and other easements that do not interfere with the use of the
Security Real property for the business being conducted thereon. Each such
commitment shall provide that such fee owner's policy committed for therein
shall be an ALTA Form B-1992, and each leasehold owner's policy shall be an ALTA
Form B-1992, or other form acceptable to Park.




                                      -41-
<PAGE>   138


                  5.09.    SCHEDULE 13D AND 13G FILINGS

                  Security shall promptly advise Park of the filing of a
Schedule 13D or 13G under the Exchange Act, if any, with respect to Security and
shall provide Park with a copy of any such Schedule promptly after receipt
thereof.

                  5.10.    SURVEY

                  For each parcel of Security Real Property as to which Park may
specifically request, within 30 days after receipt of such request, Security
shall provide to Park, at Park's cost, a current land survey of such parcel of
Security Real Property. Each survey shall be conducted and prepared by a duly
licensed land surveyor approved by Park and, unless otherwise agreed by Park in
writing, shall be a duly certified ALTA/ACSM field survey, which shall comply
with such requirements as are typical of transactions of this type and shall
confirm that the Security Real Property is not subject to any easements,
restrictions, set backs, encroachments or other limitations except utility and
other easements that do not interfere with the use of the Security Real Property
for the business then being conducted thereon, and that the Security Real
Property is not located in any flood hazard area.

                                   ARTICLE SIX
                            FURTHER COVENANTS OF PARK

                  6.01.    ACCESS TO INFORMATION

                  (a)      Park shall, and shall cause its Subsidiaries to, take
                           all action necessary to (i) afford the Officers and
                           designated representatives of Security full access
                           during normal business hours upon reasonable notice
                           to all of Park's and each Park Subsidiary's
                           respective properties and, to the extent Park or any
                           Park Subsidiary has or may provide such access, to
                           the books, records, Tax Returns (as that term is
                           defined in Section 3.01(l)) and reports, financial
                           statements, contracts and commitments, and any work
                           papers relating to any of the foregoing; (ii) furnish
                           to Security any and all documents, copies of
                           documents and information concerning Park's and each
                           Park Subsidiary's affairs as Security may reasonably
                           request; and (iii) afford full access to Security to
                           Park's and each Park Subsidiary's officers and
                           directors in order that Security may have full
                           opportunity to make such investigation as it shall
                           desire to make of the business and affairs of Park
                           and the Park Subsidiaries.

                  (b)      Park shall furnish to Security promptly after such
                           documents are available: (i) all reports, proxy
                           statements or other communications by Park to its
                           shareholders generally; and (ii) all press releases
                           relating to any transactions.


                                      -42-
<PAGE>   139



                  6.02.    OPPORTUNITY OF EMPLOYMENT; EMPLOYEE BENEFITS

                  The existing Employees of Security and the Security
Subsidiaries shall have the opportunity to continue as employees of Park or one
of its Subsidiaries, at the Effective Time; subject, however, to the right of
Park and its Subsidiaries to terminate any such employees for "cause."
Notwithstanding the preceding sentence, Park agrees to honor the employment
agreements that the Security Subsidiaries have with the Officers disclosed in
Section 6.02 of the Security Disclosure Schedule, provided that each such
agreement shall have been modified prior to the Effective Time as contemplated
in Section 8.01(h) of this Agreement. It is understood and agreed that except as
provided in the second sentence of this Section 6.02, nothing in this Section
6.02 or elsewhere in this Agreement shall be deemed to be a contract of
employment or be construed to give said employees any rights other than as
employees at will under applicable law and said employees shall not be deemed to
be third-party beneficiaries of this provision. From and after the Effective
Time, subject to the provisions of Sections 7.12 and 7.13, the Employees of
Security and the Security Subsidiaries shall continue to participate in the
Security Compensation and Benefit Plans in effect at the Effective Time unless
and until Park, in its sole discretion, shall determine that the Employees of
Security and the Security Subsidiaries shall, subject to applicable eligibility
requirements, participate in employee benefit plans of Park and that all or some
of the Security Compensation and Benefit Plans shall be terminated or merged
into certain employee benefit plans of Park. Notwithstanding the foregoing, each
Security Employee and each Security Subsidiary Employee shall be credited with
years of service with Security, the appropriate Security Subsidiary and, to the
extent credit would have been given by Security or the appropriate Security
Subsidiary for years of service with a predecessor (including any business
organization acquired by Security or any Security Subsidiary), years of service
with a predecessor of Security or a Security Subsidiary, for purposes of
eligibility and vesting (but not for benefit accrual purposes) in the employee
benefit plans of Park, and shall not be subject to any exclusion or penalty for
pre-existing conditions that were covered under the Security Compensation and
Benefit Plans immediately prior to the Effective Time, or to any waiting period
relating to such coverage. If, after the Effective Time, Park adopts a new plan
or program for its employees or executives, then to the extent its employees or
executives receive past service credits for any reason, Park shall credit
similarly-situated employees and executives of Security and the Security
Subsidiaries with equivalent credit for service with Security, a Security
Subsidiary or their respective predecessors, to the extent that years of service
credit would have been given by Security or the appropriate Security Subsidiary
for years of service with a predecessor of Security or a Security Subsidiary.
The foregoing covenants shall survive the Merger, and Park shall before the
Effective Time adopt resolutions that amend its tax-qualified retirement plans
to provide for the Security or Security Subsidiary service credits referenced
herein.

                  6.03.    AMEX LISTING

                  Park shall file a listing application with AMEX for the Park
Shares to be issued to the former holders of Security Shares in the Merger at
the time prescribed by applicable rules and regulations of AMEX. In addition,
Park will use its best efforts to maintain its listing on AMEX.




                                      -43-
<PAGE>   140


                  6.04.    TAKEOVER LAWS

                  Park shall take all necessary steps to (a) exempt (or cause
the continued exemption of) this Agreement and the Merger from the requirements
of any Takeover Law and from any provisions under its Articles of Incorporation
and Regulations, as applicable, by action of the Board of Directors of Park or
otherwise, and (b) assist in any challenge by Security to the validity, or
applicability to the Merger, of any Takeover Law.

                  6.05.    NOTIFICATION

                  Between the date of this Agreement and the Closing Date, Park
will promptly notify Security in writing if Park becomes aware of any fact or
condition that (a) causes or constitutes a breach of any of Park's
representations and warranties or (b) would (except as expressly contemplated by
this Agreement) cause or constitute a breach of any such representation or
warranty had such representation or warranty been made as of the time of
occurrence or discovery of such fact or condition. During the same period, Park
will promptly notify Security of (i) the occurrence of any breach of any of
Park's covenants contained in this Agreement, (ii) the occurrence of any event
that may make the satisfaction of the conditions in this Agreement impossible or
unlikely or (iii) the occurrence of any event that is reasonably likely,
individually or taken with all other facts, events or circumstances known to
Park, to result in a material adverse effect with respect to Park.

                  6.06.    SHAREHOLDER APPROVAL

                  Park covenants that:

                  (a)      The Board of Directors of Park will recommend the
                           adoption of this Agreement and the approval of the
                           transactions contemplated hereby to the shareholders
                           of Park, subject to that Board's fiduciary
                           obligations under Ohio law, as determined in good
                           faith after consultation with and based upon advise
                           of independent legal counsel.

                  (b)      Park will call a meeting of its shareholders (the
                           "Park Meeting") to be held as soon as reasonably
                           practicable after the Registration Statement is
                           declared effective by the SEC, for the purpose of
                           adopting this Agreement and approving the
                           transactions contemplated hereby and will, subject to
                           the provisions of Section 6.06(a), use its best
                           efforts to effect such adoption and approval. Park
                           will prepare appropriate proxy solicitation materials
                           in respect of the Park Meeting, which materials will
                           include the Joint Proxy Statement and which will be a
                           part of the Registration Statement to be submitted by
                           Park to the SEC pursuant to Section 7.08 of this
                           Agreement.

                  6.07.    OFFICERS' AND DIRECTORS' INDEMNIFICATION

                  (a)      Following the Effective Time, Park shall indemnify,
                           defend and hold harmless the present Directors,
                           Officers and Employees of Security and



                                      -44-
<PAGE>   141


                           the Security Subsidiaries (each, an "Indemnified
                           Party") against costs or expenses (including
                           reasonable attorneys' fees), judgments, fines,
                           losses, claims, damages or liabilities (collectively,
                           "Costs") incurred in connection with any claim,
                           action, suit, proceeding or investigation, whether
                           civil, criminal, administrative or investigative,
                           arising out of actions or omissions occurring on or
                           prior to the Effective Time (including, without
                           limitation, the transactions contemplated by this
                           Agreement) to the fullest extent that Security or any
                           Security Subsidiary is required to indemnify (and
                           advance expenses to) an Indemnified Party under the
                           laws of the jurisdiction of formation or
                           incorporation of Security or the relevant Security
                           Subsidiary, and the articles of incorporation and
                           regulations of Security or Third Savings or the
                           articles of association and by-laws of Security
                           National or Citizens National, in each case to the
                           extent applicable to the particular Indemnified
                           Party, as in effect on the date hereof; provided that
                           any determination required to be made with respect to
                           whether an Indemnified Party's conduct complies with
                           the standards set forth under the laws of the
                           jurisdiction of formation or incorporation, the
                           articles of incorporation and regulations of Security
                           or Third Savings or the articles of association and
                           by-laws of Security National or Citizens National, as
                           appropriate, shall be made by the court in which the
                           claim, action, suit or proceeding was brought or by
                           independent counsel (which shall not be counsel that
                           provides material services to Park) selected by Park
                           and reasonably acceptable to such Indemnified Party.

                  (b)      For a period of three years from the Effective Time,
                           Park shall use its reasonable best efforts to provide
                           that portion of directors' and officers' liability
                           insurance that serves to reimburse the present and
                           former Officers and Directors of Security and the
                           Security Subsidiaries (determined as of the Effective
                           Time) (as opposed to Security) with respect to claims
                           against such Officers and Directors arising from
                           facts or events which occurred before the Effective
                           Time, on terms no less favorable than those in effect
                           on the date hereof; provided, however, that Park may
                           substitute therefor policies providing at least
                           comparable coverage containing terms and conditions
                           no less favorable than those in effect on the date
                           hereof; provided, however that in no event shall Park
                           be required to expend more than 200 percent of the
                           current amount expended by Security (the "Insurance
                           Amount") to maintain or procure such directors' and
                           officers' liability insurance coverage; provided,
                           further that if Park is unable to maintain or obtain
                           the insurance called for by this Section 6.07(b),
                           Park shall use its reasonable best efforts to obtain
                           as much comparable insurance as is available for the
                           Insurance Amount; and provided, further, that
                           Officers and Directors of Security or any Security
                           Subsidiary may be required to make application and
                           provide customary representations and warranties to
                           Park's insurance carrier for the purpose of obtaining
                           such insurance.



                                      -45-
<PAGE>   142


                  (c)      Any Indemnified Party wishing to claim
                           indemnification under Section 6.07(a), upon learning
                           of any claim, action, suit, proceeding or
                           investigation described above, shall promptly notify
                           Park thereof; provided that the failure so to notify
                           shall not affect the obligations of Park under
                           Section 6.07(a) unless and to the extent that Park is
                           actually prejudiced as a result of such failure.

                  (d)      If Park or any of its successors or assigns shall
                           consolidate with or merge into any other entity and
                           shall not be the continuing or surviving entity of
                           such consolidation or merger or shall transfer all or
                           substantially all of its assets to any entity, then
                           and in each case, proper provision shall be made so
                           that the successors and assigns of Park shall assume
                           the obligations set forth in this Section 6.07.

                  6.08.    GOVERNANCE

                  Park's Board of Directors shall take action to cause the
directors comprising the full Board of Directors of the Surviving Corporation at
the Effective Time to be the individuals contemplated in Section 1.03(c).

                  6.09.    PARK ACQUISITION PROPOSAL

                  Park shall not accept any offer from any person regarding an
Acquisition Proposal (as defined in Section 5.04, however, references therein to
Security shall be deemed for purposes of this Section 6.09 to refer to Park)
unless such offer is expressly conditioned upon, or the offeror agrees to, the
performance by Park or its successor in interest of the obligations of park to
consummate the Merger under the terms of this Agreement. Park acknowledges that
the restrictions and agreements contained in this Section 6.09 are reasonable
and necessary to protect the legitimate interest of Security that would not be
quantifiable and for which no adequate remedy would exist at law and agrees and
consents to, in addition to all other remedies which may be available to
Security, the entry of an injunction by any court of competent jurisdiction
against consummation of any Acquisition Proposal involving Park and another
person which does not comply with this Section 6.09 until such Acquisition
Proposal does comply with this Section 6.09.

                                  ARTICLE SEVEN
                       FURTHER OBLIGATIONS OF THE PARTIES

                  7.01.    SECURITY STOCK OPTIONS

                  Prior to the Effective Time of the Merger, Park and Security
shall take all such actions as may be necessary to cause each unexpired and
unexercised Security Stock Option in effect on the date of this Agreement which
has been granted to current or former Directors, Officers or Employees of
Security or a Security Subsidiary by Security, to be converted at the Effective
Time into an option (a "Converted Option") to purchase that number of Park
Shares equal to the number of Security Shares issuable immediately prior to the
Effective time upon



                                      -46-
<PAGE>   143


exercise of the Security Stock Option multiplied by the Exchange Ratio, with an
exercise price equal to the exercise price which existed under the corresponding
Security Stock Option divided by the Exchange Ratio, and with other terms and
conditions that are the same as the terms and conditions of such Security Stock
Option immediately prior to the Effective Time (taking into account any
acceleration of vesting, if any, that would result from the Merger under the
terms of the Security Stock Option Plans as in effect on the date hereof);
provided, that with respect to any Security Stock Option that is an "incentive
stock option" within the meaning of Section 422 of the Code, the foregoing
conversion shall be carried out in a manner satisfying the requirements of
Section 424(a) of the Code. In connection with the issuance of Park Shares, Park
shall (a) reserve for issuance the number of Park Shares that will become
subject to the Converted Options pursuant to this Section 7.01 and (b) from and
after the Effective Time, upon exercise of Converted Options, make available for
issuance all Park Shares covered thereby, subject to the terms and conditions
applicable thereto.

                  7.02.    NECESSARY FURTHER ACTION

                  Each of Security and Park agrees to use its reasonable best
efforts in good faith to take, or cause to be taken, all necessary actions and
execute all additional documents, agreements and instruments required to
consummate the transactions contemplated in this Agreement.

                  7.03.    COOPERATIVE ACTION

                  Subject to the terms and conditions of this Agreement, each of
Security and Park agrees to use its reasonable best efforts in good faith to
take, or cause to be taken, all further actions and execute all additional
documents, agreements and instruments which may be reasonably required, in the
opinion of counsel for Security and counsel for Park, to satisfy all legal
requirements of the State of Ohio and the United States, so that this Agreement
and the transactions contemplated hereby will become effective as promptly as
practicable.

                  7.04.    SATISFACTION OF CONDITIONS

                  Each of Park and Security shall use its reasonable best
efforts in good faith to satisfy all of the conditions to this Agreement and to
cause the consummation of the transactions described in this Agreement,
including making all applications, notices and filings with Governmental
Authorities and Regulatory Authorities and taking all steps to secure promptly
all consents, rulings and approvals of Governmental Authorities and Regulatory
Authorities which are necessary for the performance by each party of each of its
obligations under this Agreement and the transactions contemplated hereby.

                  7.05.    ACCOUNTING AND TAX TREATMENT

                  Each of Security and Park agrees not to take any actions
subsequent to the date of this Agreement that would adversely affect the ability
of the Surviving Corporation to treat the Merger as a "pooling-of-interests" in
accordance with GAAP or Security or the shareholders of Security to characterize
the Merger as a tax-free reorganization under Section 368(a) of the Code. Each
of Security and Park agrees to take such action as may be reasonably required,
if such action may be reasonably taken to reverse the impact of any past actions
which would




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adversely impact the ability of the Surviving Corporation to treat the Merger as
a "pooling-of-interests" for accounting purposes or for the Merger to be
characterized as a tax-free reorganization under Section 368(a) of the Code.

                  7.06.    CONFIDENTIALITY

                  The Mutual Confidentiality Agreement, dated October 27, 2000,
between Security and Park (the "Confidentiality Agreement") is hereby
incorporated in this Agreement in its entirety.

                  7.07.    PRESS RELEASES

                  Each of Park and Security shall not make any press release or
other public announcement concerning the transactions contemplated by this
Agreement without the consent of the other party hereto as to the form and
contents of such press release or public announcement, except to the extent that
such press release or public announcement may be required by law or AMEX rules
to be made before such consent can be obtained.

                  7.08.    REGISTRATION STATEMENT

                  (a)      Park agrees to prepare pursuant to all applicable
                           laws, rules and regulations a registration statement
                           on Form S-4 (the "Registration Statement") to be
                           filed by Park with the SEC in connection with the
                           issuance of Park Shares in the Merger (including the
                           Joint Proxy Statement constituting a part thereof and
                           all related documents). Security agrees to cooperate,
                           and to cause the Security Subsidiaries to cooperate,
                           with Park, its counsel and its accountants, in the
                           preparation of the Registration Statement and the
                           Joint Proxy Statement; and provided that Security and
                           the Security Subsidiaries have cooperated as required
                           above, Park agrees to file the Registration
                           Statement, which will include the Joint Proxy
                           Statement and a prospectus in respect of the Park
                           Shares to be issued in the Merger (together, the
                           "Joint Proxy Statement/Prospectus") with the SEC as
                           promptly as reasonably practicable. Each of Security
                           and Park agrees to use all reasonable efforts to
                           cause the Registration Statement including the Joint
                           Proxy Statement/Prospectus to be declared effective
                           under the Securities Act as promptly as reasonably
                           practicable after the filing thereof. Park also
                           agrees to use all reasonable efforts to obtain, prior
                           to the effective date of the Registration Statement,
                           all necessary state securities law or "Blue Sky"
                           permits and approvals required to carry out the
                           transactions contemplated by this Agreement. Security
                           agrees to furnish to Park all information concerning
                           Security, the Security Subsidiaries and the Officers,
                           Directors and shareholders of Security and the
                           Security Subsidiaries as may be reasonably requested
                           in connection with the foregoing.

                  (b)      Each of Security and Park agrees, as to itself and
                           its Subsidiaries, that none of the information
                           supplied or to be supplied by it for inclusion or



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                           incorporation by reference in (i) the Registration
                           Statement will, at the time the Registration
                           Statement and each amendment or supplement thereto,
                           if any, becomes effective under the Securities Act,
                           contain any untrue statement of a material fact or
                           omit to state any material fact required to be stated
                           therein or necessary to make the statements therein
                           in light of the circumstances under which they were
                           made, not misleading, and (ii) the Joint Proxy
                           Statement/Prospectus and any amendment or supplement
                           thereto will, at the date of mailing to the Security
                           and Park shareholders, at the time of the Security
                           Meeting and at the time of the Park Meeting, as the
                           case may be, contain any untrue statement of a
                           material fact or omit to state any material fact
                           required to be stated therein or necessary to make
                           the statements therein in light of the circumstances
                           under where they were made not misleading. Each of
                           Security and Park further agrees, if it shall become
                           aware prior to the Effective Time of any information
                           furnished by it that would cause any of the
                           statements in the Registration Statement and the
                           Joint Proxy Statement/Prospectus to be false or
                           misleading with respect to any material fact, or to
                           omit to state any material fact necessary to make the
                           statements therein not false or misleading, to
                           promptly inform the other party thereof and to take
                           the necessary steps to correct the Registration
                           Statement and the Joint Proxy Statement/Prospectus.

                  (c)      Park agrees to advise Security, promptly after Park
                           receives notice thereof, of the time when the
                           Registration Statement has become effective or any
                           supplement or amendment has been filed, of the
                           issuance of any stop order or the suspension of the
                           qualification of Park Shares for offering or sale in
                           any jurisdiction, of the initiation or threat of any
                           proceeding for any such purpose, or of any request by
                           the SEC for the amendment or supplement of the
                           Registration Statement or for additional information.

                  7.09.    REGULATORY APPLICATIONS

                  Park and Security and their respective Subsidiaries shall
cooperate and use their respective reasonable best efforts to prepare all
documentation, to timely effect all filings and to obtain all permits, consents,
approvals and authorizations of all third parties and Governmental and
Regulatory Authorities necessary to consummate the transactions contemplated by
this Agreement. Each of Park and Security shall have the right to review in
advance, and to the extent practicable, each will consult with the other, in
each case subject to applicable laws relating to the exchange of information,
with respect to, and shall be provided in advance so as to reasonably exercise
its right to review in advance, all material written information submitted to
any third party or any Governmental or Regulatory Authority in connection with
the transactions contemplated by this Agreement. In exercising the foregoing
right, each of the parties hereto agrees to act reasonably and as promptly as
practicable. Each party hereto agrees that it will consult with the other party
hereto with respect to the obtaining of all material permits, consents,
approvals and authorizations of all third parties and Governmental and
Regulatory Authorities necessary or advisable to consummate the transactions
contemplated by this Agreement and each


                                      -49-
<PAGE>   146


party will keep the other apprised of the status of material matters relating to
completion of the transactions contemplated hereby. Each party agrees, upon
request, to furnish the other party with all information concerning itself, its
Subsidiaries, directors, officers and shareholders and such other matters as may
be reasonably necessary or advisable in connection with any filing, notice or
application made by or on behalf of such other party or of its Subsidiaries to
any third party or Governmental or Regulatory Authority.

                  7.10.    DIVIDENDS

                  After the date of this Agreement, each of Security and Park
shall coordinate with the other the payment of dividends with respect to the
Security Shares and the Park Shares and the record dates and payment dates
relating thereto, it being the intention of the parties hereto that the former
holders of Security Shares shall not receive two dividends, or fail to receive
one dividend, for any single calendar quarter with respect to their Security
Shares and/or the Park Shares that any such holder receives in exchange for such
Security Shares in the Merger.

                  7.11.    SUPPLEMENTAL ASSURANCES

                  (a)      On the date the Registration Statement becomes
                           effective and on the Closing Date, Security shall
                           deliver to Park a certificate signed by its principal
                           executive officer and its principal financial officer
                           to the effect that, to such officers' knowledge, the
                           information contained in the Registration Statement
                           relating to the business, financial condition and
                           affairs of Security and the Security Subsidiaries,
                           does not contain any untrue statement of a material
                           fact or omit to state any material fact required to
                           be stated therein or necessary to make the statements
                           therein not misleading in light of the circumstances
                           under which they were made.

                  (b)      On the date the Registration Statement becomes
                           effective and on the Closing Date, Park shall deliver
                           to Security a certificate signed by its chief
                           executive officer and its chief financial officer to
                           the effect that, to such officers' knowledge, the
                           Registration Statement (other than the information
                           contained therein relating to the business, financial
                           condition and affairs of Security and the Security
                           Subsidiaries) does not contain any untrue statement
                           of a material fact or omit to state any material fact
                           required to be stated therein or necessary to make
                           the statements therein not misleading in light of the
                           circumstances under which they were made.

                  7.12.    SECURITY SPLIT DOLLAR PLAN

                  Prior to the Closing Date, Security and Park shall take all
necessary actions and shall otherwise cooperate to ensure that following the
Effective Time each participant in the Security Split Dollar insurance benefit
program (the "Security Split Dollar Plan") immediately prior to the Effective
Time shall continue to receive the full benefit of the vested portion of such
participant's death benefit under the terms of the Security Split Dollar Plan
for the life of the participant.


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                  7.13.    SECURITY PENSION PLAN

                  If Park merges the Security Pension Plan into the Park Pension
Plan or otherwise ceases to maintain the Security Pension Plan, each participant
under the Security Pension Plan immediately prior to the merger of the Pension
Plans shall be provided with the same accrued benefit under the Park Pension
Plan or any successor defined benefit plan of Park (using the same actuarial
assumptions, discount rates and service credit) that the participant was
entitled to receive under the Security Pension Plan immediately prior to the
merger of the Pension Plans. Park also agrees that the former Security Employees
who become participants in the Park Pension Plan would receive, at such time as
they are entitled to receive benefits under the Park Pension Plan, the higher
of:

                  (a) a benefit comprised of two components: (i) a benefit
                  computed under the Security Pension Plan formula in respect of
                  the period of participation therein prior to the merger of the
                  Security Pension Plan and the Park Pension Plan; and (ii) a
                  benefit computed under the Park Pension Plan formula in
                  respect of the period following the merger of the Security
                  Pension Plan and the Park Pension Plan; or

                  (b) the benefit computed by using the Park Pension Plan
                  formula and based upon their combined periods of service for
                  purposes of the Park Pension Plan and the Security Pension
                  Plan.

                                  ARTICLE EIGHT

             CONDITIONS PRECEDENT TO THE OBLIGATIONS OF THE PARTIES

                  8.01.    CONDITIONS TO THE OBLIGATIONS OF PARK

                  The obligations of Park under this Agreement shall be subject
to the satisfaction, or written waiver by Park prior to the Closing Date, of
each of the following conditions precedent:

                  (a)      The representations and warranties of Security set
                           forth in this Agreement shall be true and correct in
                           all material respects as of the date of this
                           Agreement and as of the Closing Date as though such
                           representations and warranties were also made as of
                           the Closing Date, except (i) that those
                           representations and warranties which by their terms
                           speak as of a specific date shall be true and correct
                           as of such date and (ii) where the failure to be so
                           true and correct would not, individually or in the
                           aggregate, have or be reasonably likely to have a
                           material adverse effect on Security or any Security
                           Subsidiary; and Park shall have received a
                           certificate, dated the Closing Date, signed on behalf
                           of Security by the chief executive officer and the
                           chief financial officer of Security to such effect.



                                      -51-
<PAGE>   148



                  (b)      Security shall have performed in all material
                           respects all of its covenants and obligations under
                           this Agreement to be performed by it on or prior to
                           the Closing Date, including those relating to the
                           Closing, and Park shall have received a certificate,
                           dated the Closing Date, signed on behalf of Security
                           by the chief executive officer and the chief
                           financial officer of Security to such effect.

                  (c)      In the aggregate, an amount of less than ten percent
                           (10%) of the number of Park Shares to be issued in
                           the Merger shall be (i) subject to purchase as
                           fractional Park Share interests, (ii) Security
                           Dissenting Shares in connection with the Merger
                           contemplated by this Agreement; and (iii) held by
                           shareholders of Park who have demanded payment of the
                           appraised value of their Park Shares under OGCL
                           Section 1701.85 in connection with the Merger.

                  (d)      Park shall have received the written opinion of its
                           counsel, dated the Closing Date, to the effect that,
                           on the basis of facts, representations and
                           assumptions set forth in such opinion, the Merger
                           constitutes a tax-free reorganization within the
                           meaning of Section 368(a) of the Code. In rendering
                           its opinion, counsel to Park will require and rely
                           upon representations contained in letters from Park
                           and Security.

                  (e)      Park shall have received the written opinion of
                           Werner & Blank Co., L.P.A., counsel to Security,
                           dated the Closing Date, to the effect that, on the
                           basis of the facts, representations and assumptions
                           set forth in the opinion: (i) Security is a
                           corporation duly incorporated, validly existing and
                           in good standing under the laws of the State of Ohio;
                           (ii) Security National and Citizens National are
                           national banking associations duly organized, validly
                           existing and in good standing under the laws of the
                           United States of America; (iii) Third Savings is an
                           Ohio state-chartered savings association, duly
                           organized, validly existing and in good standing
                           under the laws of the State of Ohio; (iv) all
                           eligible accounts of deposit in each Security
                           Subsidiary are insured by the FDIC to the fullest
                           extent permitted by law; (v) Security is a duly and
                           validly registered bank holding company under the
                           BHCA; (vi) this Agreement has been duly approved by
                           the Board of Directors of Security and duly adopted
                           by the shareholders of Security and no further
                           corporate proceedings are required to authorize the
                           transactions contemplated by this Agreement; (vii)
                           this Agreement has been duly executed by Security and
                           constitutes a binding obligation on Security
                           enforceable in accordance with its terms against
                           Security, except as the same may be limited by
                           bankruptcy, insolvency, fraudulent conveyance,
                           reorganization, moratorium, and other similar laws
                           relating to or affecting the enforcement of
                           creditors' rights generally, by general equitable
                           principles, regardless of whether enforceability is
                           considered in a proceeding in equity or at law and an
                           implied covenant of good faith and fair dealing;
                           (viii) the execution and delivery of this



                                      -52-
<PAGE>   149


                           Agreement did not, and the consummation of the Merger
                           will not, conflict with any provision of the articles
                           of incorporation, articles of association,
                           regulations, bylaws or other governing documents of
                           Security or the Security Subsidiaries; (ix) Security
                           has the full corporate power and authority to perform
                           its obligations under this Agreement and to
                           consummate the transactions contemplated by this
                           Agreement; (x) Security and the Security Subsidiaries
                           have the full corporate power and authority to own
                           their respective properties and to carry on their
                           respective businesses as presently conducted; (xi)
                           upon the filing of the certificate of merger with the
                           Secretary of State, the Merger shall become effective
                           in accordance with the terms thereof; and (xii) such
                           counsel knows of no pending or threatened actions,
                           suits, proceedings, claims or investigations which
                           would prevent the consummation of this Agreement or
                           any of the transactions contemplated hereby or
                           declare the same to be unlawful or cause the
                           rescission thereof.

                  (f)      Park shall have received a copy of a statement,
                           issued by Security pursuant to Section 1.897-2(h) of
                           the regulations issued under the Code, certifying
                           that the Security Shares are not an U.S. real
                           property interest and dated not more than thirty days
                           prior to the Closing Date.

                  (g)      Security shall have obtained the consent or approval
                           of each person (other than Governmental and
                           Regulatory Authorities) whose consent or approval
                           shall be required in order to permit the succession
                           by the Surviving Corporation pursuant to the Merger
                           to any obligation, right or interest of Security or
                           any Security Subsidiary under any loan or credit
                           agreement, note, mortgage, indenture, lease, license
                           or other agreement or instrument, except those for
                           which failure to obtain such consents and approvals
                           would not, individually or in the aggregate, have a
                           material adverse effect, after the Effective Time, on
                           the Surviving Corporation.

                  (h)      The employment agreement between Harry O. Egger and
                           Security National shall have been amended in a manner
                           satisfactory to Park to provide that the term thereof
                           shall end on the third anniversary of the Closing
                           Date. Each of (i) the employment agreement between J.
                           William Stapleton and Security National, (ii) the
                           employment agreement between William C. Fralick and
                           Security National, (iii) the employment agreement
                           between James R. Wilson and Citizens National, and
                           (iv) the employment agreement between Scott A.
                           Gabriel and Third Savings, shall have been amended in
                           a manner satisfactory to Park to provide that the
                           term thereof shall end on the second anniversary of
                           the Closing Date.



                                      -53-
<PAGE>   150


                  8.02.    CONDITIONS TO THE OBLIGATIONS OF SECURITY

                  The obligations of Security under this Agreement shall be
subject to satisfaction, or written waiver by Security prior to the Closing
Date, of each of the following conditions precedent:

                  (a)      The representations and warranties of Park set forth
                           in this Agreement shall be true and correct in all
                           material respects as of the date of this Agreement
                           and as of the Closing Date as though such
                           representations and warranties were also made as of
                           the Closing Date, except (i) that representations and
                           warranties which by their terms speak as of a
                           specific date shall be true and correct as of such
                           date and (ii) where the failure to be so true and
                           correct would not, individually or in the aggregate,
                           have or be reasonably likely to have a material
                           adverse effect on Park and its Subsidiaries taken as
                           a whole; and Security shall have received a
                           certificate, dated the Closing Date, signed on behalf
                           of Park by the chief executive officer and the chief
                           financial officer to such effect.

                  (b)      Park shall have performed in all material respects
                           all of its covenants and obligations under this
                           Agreement to be performed by it on or prior to the
                           Closing Date, including those related to the Closing,
                           and Security shall have received a certificate, dated
                           the Closing Date, signed on behalf of Park by the
                           chief executive officer and the chief financial
                           officer to such effect.

                  (c)      Security shall have received the written opinion of
                           counsel to Park, dated the Closing Date, to the
                           effect that, on the basis of facts, representations
                           and assumptions set forth in such opinion, (i) the
                           Merger constitutes a tax-free reorganization within
                           the meaning of Section 368(a) of the Code, and (ii)
                           no gain or loss will be recognized by shareholders of
                           Security who receive Park Shares in exchange for
                           Security Shares, and cash in lieu of fractional Park
                           Share interests, other than the gain or loss to be
                           recognized as to cash received in lieu of fractional
                           Park Share interests. In rendering its opinion,
                           counsel to Park will require and rely upon
                           representations contained in letters from Security
                           and Park.

                  (d)      Security shall have received the written opinion of
                           Vorys, Sater, Seymour and Pease LLP, counsel to Park,
                           dated the Closing Date, to the effect that, on the
                           basis of the facts, representations and assumptions
                           set forth in the opinion, (i) Park is a corporation
                           incorporated, duly validly existing and in good
                           standing under the laws of the State of Ohio; (ii)
                           Park is a duly and validly registered bank holding
                           company under the BHCA; (iii) this Agreement has been
                           duly approved by the Board of Directors of Park and
                           duly adopted by the shareholders of Park and no
                           further corporate proceedings are required to
                           authorize the transactions contemplated by this
                           Agreement; (iv) this Agreement has been duly executed
                           by Park and



                                      -54-
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                           constitutes the binding obligation of Park,
                           enforceable in accordance with its terms against
                           Park, except as the same may be limited by
                           bankruptcy, insolvency, fraudulent conveyance,
                           reorganization, moratorium and other similar laws
                           relating to or affecting the enforcement of
                           creditors' rights generally, by general equitable
                           principles (regardless of whether enforceability is
                           considered in a proceeding in equity or at law) and
                           by an implied covenant of good faith and fair
                           dealing; (v) the execution and delivery of this
                           Agreement did not, and the consummation of the Merger
                           will not, conflict with any provision of the Articles
                           of Incorporation or Regulations of Park; (vi) Park
                           has the full corporate power and authority to perform
                           its obligations under this Agreement and to
                           consummate the transactions contemplated by this
                           Agreement; (vii) the Park Shares to be issued as
                           Merger Shares, when issued, shall be duly authorized,
                           fully paid and non-assessable; and (viii) upon the
                           filing of the appropriate certificate of merger with
                           the Secretary of State, the Merger shall become
                           effective in accordance with the terms thereof.

                  (e)      Park shall have obtained the consent or approval of
                           each person (other than Governmental and Regulatory
                           Authorities) whose consent or approval shall be
                           required in connection with the transactions
                           contemplated hereby under any loan or credit
                           agreement, note, mortgage, indenture, lease, license
                           or other agreement or instrument, except those for
                           which failure to obtain such consents and approvals
                           would not, individually or in the aggregate, have a
                           material adverse effect, after the Effective Time, on
                           the Surviving Corporation.

                  8.03.    MUTUAL CONDITIONS

                  The obligations of Security and Park under this Agreement
shall be subject to the satisfaction, or written waiver by Park and Security
prior to the Closing Date, of each of the following conditions precedent:

                  (a)      The shareholders of Security and the shareholders of
                           Park shall have duly adopted this Agreement by the
                           required vote.

                  (b)      All approvals of Governmental Authorities and
                           Regulatory Authorities required to consummate the
                           transactions contemplated by this Agreement shall
                           have been obtained and shall remain in full force and
                           effect and all statutory waiting periods in respect
                           thereof shall have expired and no such approvals or
                           statute, rule or order shall contain any conditions,
                           restrictions or requirements which Park reasonably
                           determines would either before or after the Effective
                           Time (i) have a material adverse effect on Park and
                           its Subsidiaries take as a whole after giving effect
                           to the consummation of the Merger; or (ii) prevent
                           Park from realizing the major portion of the economic
                           benefits of the Merger and the transactions
                           contemplated thereby which Park currently anticipates
                           obtaining.



                                      -55-
<PAGE>   152


                  (c)      No temporary restraining order, preliminary or
                           permanent injunction or other order issued by a court
                           of competent jurisdiction or other legal restraint or
                           prohibition preventing the consummation of the Merger
                           shall be in effect. No Governmental or Regulatory
                           Authority of competent jurisdiction shall have
                           enacted, issued, promulgated, enforced, threatened,
                           commenced a proceeding with respect to or entered any
                           statute, rule, regulation, judgment, decree,
                           injunction or other order (whether temporary,
                           preliminary or permanent) prohibiting or delaying
                           consummation of the transactions contemplated by this
                           Agreement.

                  (d)      The Registration Statement shall have become
                           effective under the Securities Act and no stop order
                           or similar restraining order suspending the
                           effectiveness of the Registration Statement shall
                           have been issued and no proceeding for that purpose
                           shall have been initiated or, to the knowledge of the
                           parties, threatened by the SEC.

                  (e)      Park shall have received all state securities and
                           "blue sky" permits and other authorizations and
                           approvals necessary to consummate the Merger and the
                           transactions contemplated hereby and no order
                           restraining the ability of Park to issue Park Shares
                           pursuant to the Merger shall have been issued and no
                           proceedings for that purpose shall have been
                           initiated or threatened by any state securities
                           administrator.

                  (f)      Park and Security shall have received from their
                           independent auditors, a letter dated the Closing
                           Date, stating such independent auditors' opinion
                           that, based upon the information furnished, the
                           Merger shall qualify for "pooling-of-interests"
                           accounting treatment.

                  (g)      The Park Shares to be issued in the Merger shall have
                           been approved for listing on AMEX subject to official
                           notice of issuance.

                                  ARTICLE NINE
                                     CLOSING

                  9.01.    CLOSING

                  The closing (the "Closing") of the transactions contemplated
by this Agreement shall be held at the offices of Park, 50 North Third Street,
Newark, Ohio 43055, commencing at 10:00 a.m., local time, on (a) the date
designated by Park, which date shall not be earlier than the third business day
to occur after the last of the conditions set forth in Article Eight shall have
been satisfied or waived in accordance with the terms of this Agreement
(excluding conditions that, by their terms, cannot be satisfied until the
Closing Date) or later than the last business day of the month in which such
third business day occurs; provided, no such election shall cause the Closing to
occur on a date after that specified in Section 11.01(b)(i) of this Agreement or
after the date or dates on which any Governmental or Regulatory Authority
approval or any extension


                                      -56-
<PAGE>   153


thereof expires, or (b) such other date to which the parties agree in writing.
The date of the Closing is sometimes herein called the "Closing Date."

                  9.02.    CLOSING TRANSACTIONS REQUIRED OF PARK

                  At the Closing, Park shall cause all of the following to be
delivered to Security:

                  (a)      A certificate of merger duly executed by Park in
                           accordance with Section 1701.81 of the OGCL and in
                           appropriate form for filing with the Secretary of
                           State.

                  (b)      The certificates of Park contemplated by Section
                           8.02(a) and (b) of this Agreement.

                  (c)      Copies of resolutions adopted by the directors and
                           the shareholders of Park, approving and adopting this
                           Agreement and authorizing the consummation of the
                           transactions described herein, accompanied by a
                           certificate of the secretary or assistant secretary
                           of Park, dated as of the Closing Date, and certifying
                           (i) the date and manner of adoption of each such
                           resolution; and (ii) that each such resolution is in
                           full force and effect, without amendment or repeal,
                           as of the Closing Date.

                  (d)      The opinions of counsel to Park contemplated by
                           Sections 8.02(c) and 8.02(d) of this Agreement.

                  9.03.    CLOSING TRANSACTIONS REQUIRED OF SECURITY

                  At the Closing, Security shall cause all of the following to
be delivered to Park:

                  (a)      A certificate of merger duly executed by Security in
                           accordance with Section 1701.81 of the OGCL and in
                           appropriate form for filing with the Ohio Secretary
                           of State.

                  (b)      The certificates of Security contemplated by Sections
                           8.01(a) and (b) of this Agreement.

                  (c)      Copies of all resolutions adopted by the directors
                           and the shareholders of Security approving and
                           adopting this Agreement and authorizing the
                           consummation of the transactions described herein,
                           accompanied by a certificate of the secretary or the
                           assistant secretary of Security, dated as of the
                           Closing Date, and certifying (i) the date and manner
                           of the adoption of each such resolution; and (ii)
                           that each such resolution is in full force and
                           effect, without amendment or repeal, as of the
                           Closing Date.

                  (d)      The opinion of counsel to Security contemplated by
                           Section 8.01(e) of this Agreement.


                                      -57-
<PAGE>   154


                  (e)      The agreements referred to in Section 5.06 from each
                           Rule 145 Affiliate.


                                   ARTICLE TEN
            NON-SURVIVAL OF REPRESENTATIONS, WARRANTIES AND COVENANTS

                  10.01.   NON-SURVIVAL OF REPRESENTATIONS, WARRANTIES AND
                           COVENANTS

                  The representations, warranties and covenants of Park and
Security set forth in this Agreement, or in any document delivered pursuant to
the terms hereof or in connection with the transactions contemplated hereby,
shall not survive the Closing and the consummation of the transactions referred
to herein, other than covenants which by their terms are to survive or be
performed after the Effective Time (including, without limitation, those set
forth in Sections 6.02, 6.07, 6.08, 7.01, 7.05, 7.06, 7.07, 7.12 and 7.13, this
Article Ten and Article Twelve); except that no such representations, warranties
or covenants shall be deemed to be terminated or extinguished so as to deprive
Park (or any director, officer or controlling person thereof) of any defense in
law or equity which otherwise would be available against the claims of any
person, including, without limitation, any shareholder or former shareholder of
either Security or Park.

                                 ARTICLE ELEVEN
                                   TERMINATION

                  11.01.   TERMINATION

                  This Agreement may be terminated, and the Merger may be
abandoned, at any time prior to the Effective Time, whether prior to or after
this Agreement has been adopted by the shareholders of Security and/or the
shareholders of Park:

                  (a)      By mutual written agreement of Security and Park duly
                           authorized by action taken by or on behalf of their
                           respective Boards of Directors;

                  (b)      By either Security or Park upon written notification
                           to the non-terminating party by the terminating
                           party:

                           (i)      at any time after October 31, 2001, if the
                                    Merger shall not have been consummated on or
                                    prior to such date and such failure to
                                    consummate the Merger is not caused by a
                                    breach of this Agreement by the terminating
                                    party;

                           (ii)     if the shareholders of Security shall not
                                    have adopted this Agreement (the "Security
                                    Shareholders' Adoption") by reason of the
                                    failure to obtain the requisite vote upon a
                                    vote held at a Security Meeting, or any
                                    adjournment thereof;

                           (iii)    if the shareholders of Park shall not have
                                    adopted this Agreement (the "Park
                                    Shareholders' Adoption") by reason of the
                                    failure to



                                      -58-
<PAGE>   155


                                    obtain the requisite vote upon a vote held
                                    at a Park Meeting, or any adjournment
                                    thereof;

                           (iv)     the approval of any Governmental or
                                    Regulatory Authority required for
                                    consummation of the Merger and the other
                                    transactions contemplated by this Agreement
                                    shall have been denied by final
                                    non-appealable action of such Governmental
                                    or Regulatory Authority.

                  (c)      By Park by providing written notice to Security:

                           (i)      if prior to the Closing Date, any
                                    representation and warranty of Security
                                    shall have become untrue such that the
                                    condition set forth at Section 8.01(a) would
                                    not be satisfied and which breach has not
                                    been cured within 30 days following receipt
                                    by Security of written notice of breach or
                                    is incapable of being cured during such time
                                    period; or

                           (ii)     if Security shall have failed to comply in
                                    any material respect with any covenant or
                                    agreement on the part of Security contained
                                    in this Agreement required to be complied
                                    with prior to the date of such termination,
                                    which failure to comply shall not have been
                                    cured within 30 days following receipt by
                                    Security of written notice of such failure
                                    to comply or is incapable of being cured
                                    during such time period.

                  (d)      By Security by providing written notice to Park:

                           (i)      if prior to the Closing Date, any
                                    representation and warranty of Park shall
                                    have become untrue such that the condition
                                    set forth at Section 8.02(a) would not be
                                    satisfied and which breach has not been
                                    cured within 30 days following receipt by
                                    Park of written notice of breach or is
                                    incapable of being cured during such time
                                    period;

                           (ii)     if Park shall have failed to comply in any
                                    material respect with any covenant or
                                    agreement on the part of Park contained in
                                    this Agreement required to be complied with
                                    prior to the date of such termination, which
                                    failure to comply shall not have been cured
                                    within 30 days following receipt by Park of
                                    written notice of such failure to comply or
                                    is incapable of being cured during such time
                                    period;

                           (iii)    if the Board of Directors of Security
                                    determines in good faith, based upon advice
                                    from independent counsel, that termination
                                    of this Agreement is required for the Board
                                    of Directors of Security to comply with its
                                    fiduciary duties to shareholders imposed by
                                    law by



                                      -59-
<PAGE>   156


                                    reason of an Acquisition Proposal having
                                    been made and provided Security complied
                                    with its obligations under Section 5.04 and
                                    provided further that Security's ability to
                                    terminate pursuant to this subsection
                                    (d)(iii) is conditioned upon the prior
                                    payment by Security to Park of any amounts
                                    owed by Security to Park pursuant to Section
                                    11.02(b); or

                           (iv)     if the Board of Directors of Security so
                                    determines by a vote of a majority of the
                                    members of the entire Board, at any time
                                    during the three-day period commencing with
                                    the Determination Date (as defined below) if
                                    both of the following conditions are
                                    satisfied: (A) the Average Closing Price on
                                    the Determination Date shall be less than
                                    $77.50; and (B) the ratio of the Average
                                    Closing Price to the Starting Price (as
                                    defined below), rounded to the nearest one
                                    one-hundredth, shall be less than the number
                                    obtained by dividing the Final Index Price
                                    (as defined below) on the Determination Date
                                    by the Initial Index Price (as defined
                                    below) on the Starting Date (as defined
                                    below), rounded to the nearest one
                                    one-hundredth.

                                    For purposes of this Section 11.01(d)(iv),
                                    the following terms shall have the meanings
                                    indicated:

                                    "Determination Date" shall mean the last day
                                    of the 20 trading day period referenced in
                                    the definition of Average Price.

                                    "Final Index Price" shall mean the sum of
                                    the Final Price for each company comprising
                                    the Index Group multiplied by the
                                    appropriate weighting.

                                    "Final Price," with respect to any company
                                    belonging to the Index Group, shall mean the
                                    average of the daily closing sales prices of
                                    a share of common stock of such company, as
                                    reported on the consolidated transactions
                                    reporting system for the market or exchange
                                    on which such common stock is principally
                                    traded, during the period of 20 trading days
                                    ending on the Determination Date.

                                    "Index Group" shall mean the ten bank
                                    holding companies listed below, the common
                                    stock of which shall be publicly traded and
                                    as to which there shall not have been a
                                    publicly announced proposal since the
                                    Starting Date and before the Determination
                                    Date for any such company to be acquired. In
                                    the event that the common stock of any such
                                    company ceases to be publicly traded or a
                                    proposal to acquire any such company is
                                    announced after the Starting Date and before
                                    the Determination Date, such company shall
                                    be removed from the Index Group, and the
                                    weights attributed to the remaining



                                      -60-
<PAGE>   157
                                    companies shall be adjusted proportionately
                                    for purposes of determining the Final Index
                                    Price. The ten bank holding companies and
                                    the weights attributed to them are as
                                    follows:


<TABLE>
<CAPTION>
                                                Bank Holding Company                    Ticker          Weighting
                                                --------------------                    ------          ---------
<S>                                                                                     <C>              <C>
                                    Amcore Financial, Inc.                              AMFI             10.000%
                                    First Financial Bancorp.                            FFBC             10.000%
                                    Fifth Third Bancorp                                 FITB             10.000%
                                    FirstMerit Corporation                              FMER             10.000%
                                    Fulton Financial Corporation                        FULT             10.000%
                                    Integra Bank Corporation                            IBNK             10.000%
                                    Mercantile Bankshares Corporation                   MRBK             10.000%
                                    National Penn Bancshares, Inc.                      NPBC             10.000%
                                    S&T Bancorp, Inc.                                   STBA             10.000%
                                    Sky Financial Group, Inc.                           SKYF             10.000%
</TABLE>

                                    "Initial Index Price" shall mean the sum of
                                    each per share closing price of the common
                                    stock of each company comprising the Index
                                    Group multiplied by the applicable
                                    weighting, as such prices are reported on
                                    the consolidated transactions reporting
                                    system for the market or exchange on which
                                    such common stock is principally traded on
                                    the Starting Date.

                                    "Starting Date" shall mean the last trading
                                    day immediately preceding the date of the
                                    first public announcement of entry into this
                                    Agreement.

                                    "Starting Price" shall mean the closing
                                    price of a Park Share on AMEX (as reported
                                    in The Wall Street Journal, or if not
                                    reported therein, in another authoritative
                                    source) on the Starting Date.

                                    If any company belonging in the Index Group
                                    declares or effects a stock dividend,
                                    reclassification, recapitalization,
                                    split-up, combination, exchange of shares or
                                    similar transaction between the Starting
                                    Date and the Determination Date, the prices
                                    for the common stock of such company shall
                                    be appropriately adjusted for the purposes
                                    of applying this Section 11.01(d)(iv).

                  11.02.   EFFECT OF TERMINATION.

                  (a)      If this Agreement is validly terminated by either
                           Security or Park pursuant to Section 11.01, this
                           Agreement will forthwith become null and void and
                           there will be no liability or obligation on the part
                           of either Security or Park, except (i) that the
                           provisions of Sections 5.04, 7.06, 7.07, 7.08(b) and
                           12.07 and this Section 11.02 will continue to apply
                           following any such



                                      -61-
<PAGE>   158


                           termination, (ii) that nothing contained herein shall
                           relieve any party hereto from liability for willful
                           breach of its representations, warranties, covenants
                           or agreements contained in this Agreement and (iii)
                           as provided in paragraph (b) below.

                  (b)      In the event that any person or group shall have made
                           an Acquisition Proposal and thereafter: (i) this
                           Agreement is terminated by Security pursuant to
                           Section 11.01(d)(iii) or (ii) this Agreement is
                           terminated for any other reason (other than by
                           Security pursuant to Section 11.01(d)(i), (ii) or
                           (iv) or termination by either party pursuant to
                           Section 11.01(a) or Section 11.01(b)(i) (unless
                           Security shall have caused the Merger not to be
                           consummated by October 31, 2001 for the purposes of
                           pursuing an Acquisition Proposal), (ii) (unless the
                           Security directors shall have failed to recommend the
                           Merger or withdrawn or modified or announced their
                           intention not to recommend the Merger prior to the
                           Security Meeting, failed to solicit proxies in favor
                           of the Merger or recommended or approved another
                           Acquisition Proposal), (iii) or (iv)) and, in the
                           case of this clause (ii) only, a definitive agreement
                           with respect to such Acquisition Proposal is executed
                           within one year after such termination, and pursuant
                           to which each outstanding Security Share is entitled
                           to receive at least $22.04 in consideration, then
                           Security shall pay to Park, by wire transfer of same
                           day funds, either on the date contemplated in Section
                           11.01(d)(iii) if applicable, or otherwise, within two
                           (2) business days after such amount becomes due, a
                           termination fee of $10,000,000.

                  (c)      In the event of a termination of this Agreement
                           pursuant to which a payment is made in full
                           compliance with Section 11.02(b), the receipt of such
                           payment shall serve as liquidated damages with
                           respect to any breach of this Agreement by the party
                           which has made such payment giving rise to such
                           termination, and the receipt of any such payment
                           shall be the sole and exclusive remedy (at law or in
                           equity) with respect to any such breach.

                  (d)      In the event any action, suit, proceeding or claim is
                           commenced or asserted by a party against another
                           party and/or any director or officer of such other
                           party relating, directly or indirectly, to this
                           Agreement, it is expressly agreed that no party shall
                           be entitled to obtain any punitive, exemplary,
                           treble, or consequential damages of any type under
                           any circumstances in connection with such action,
                           suit, proceeding or claim, regardless of whether such
                           damages may be available under law, the parties
                           hereby waiving their rights, if any, to recover any
                           such damages in connection with any such action,
                           suit, proceeding or claim.



                                      -62-
<PAGE>   159


                                 ARTICLE TWELVE
                                  MISCELLANEOUS

                  12.01.   NOTICES

                  All notices, requests, demands and other communications
required or permitted to be given under this Agreement shall be given in writing
and shall be deemed to have been duly given (a) on the date of delivery if
delivered by hand or by telecopy or telefacsimile, upon confirmation of receipt,
(b) on the first business day following the date of dispatch if delivered by a
recognized next-day courier service, or (c) on the third business day following
the date of mailing if sent by certified mail, postage prepaid, return receipt
requested. All notices thereunder shall be delivered to the following addresses:

                           If to Security, to:

                           Security Banc Corporation
                           40 South Limestone Street
                           Springfield, OH 45502
                           Attention:  Harry O. Egger
                           Facsimile Number:  (937) 324-6966

                           with a copy to:

                           Werner & Blank Co., L.P.A.
                           7205 West Central Avenue
                           Toledo, OH 43617
                           Attention:  Martin Werner, Esq.
                           Facsimile Number:  (419) 841-8380

                           If to Park, to:

                           Park National Corporation
                           50 North Third Street
                           Newark, OH  43055
                           Attention:  C. Daniel DeLawder
                           Facsimile Number:  (740) 349-3765

                           with a copy to:

                           Vorys, Sater, Seymour and Pease LLP
                           52 East Gay Street
                           P.O. Box 1008
                           Columbus, OH  43216-1008
                           Attention:  Elizabeth Turrell Farrar, Esq.
                           Facsimile Number:  (614) 719-4708



                                      -63-
<PAGE>   160


Any party to this Agreement may, by notice given in accordance with this Section
12.01, designate a new address for notices, requests, demands and other
communications to such party.

                  12.02.   COUNTERPARTS

                  This Agreement may be executed in one or more counterparts,
each of which shall be deemed to be a duplicate original, but all of which taken
together shall be deemed to constitute a single instrument.

                  12.03.   ENTIRE AGREEMENT

                  This Agreement (including each exhibit and schedule provided
pursuant hereto), together with the Confidentiality Agreement, represents the
entire agreement between the parties hereto in respect of the subject matter of
this Agreement and supersedes any and all prior and contemporaneous agreements
between the parties hereto in connection with the subject matter of this
Agreement, other than the Confidentiality Agreement.

                  12.04.   SUCCESSORS AND ASSIGNS

                  This Agreement shall inure to the benefit of and be binding
upon the respective successors and assigns (including successive, as well as
immediate, successors and assigns) of the parties hereto. This Agreement may not
be assigned by either party hereto without the prior written consent of the
other party.

                  12.05.   CAPTIONS

                  The captions contained in this Agreement are included only for
convenience of reference and do not define, limit, explain or modify this
Agreement or its interpretation, construction or meaning and are in no way to be
construed as part of this Agreement.

                  12.06.   GOVERNING LAW

                  This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Ohio, without giving effect to
principles of conflicts or choice of laws (except to the extent that mandatory
provisions of Federal law are applicable).

                  12.07.   PAYMENT OF FEES AND EXPENSES

                  Except as otherwise agreed in writing, each party hereto shall
pay all costs and expenses, including legal and accounting fees, and all
expenses relating to its performance of, and compliance with, its undertakings
herein, except that printing and mailing expenses shall be shared equally
between Security and Park. All fees to be paid to Governmental and Regulatory
Authorities and the SEC in connection with the transactions contemplated by this
Agreement shall be borne by Park.


                                      -64-
<PAGE>   161


                  12.08.   AMENDMENT

                  From time to time and at any time prior to the Effective Time,
this Agreement may be amended only by an agreement in writing executed in the
same manner as this Agreement, after authorization of such action by the Boards
of Directors of the Constituent Corporations; except that after the earlier to
occur of the Security Meeting and the Park Meeting, this Agreement may not be
amended if it would violate the OGCL or the federal securities laws.

                  12.09.   WAIVER

                  The rights and remedies of the parties to this Agreement are
cumulative and not alternative. Neither the failure nor any delay by any party
in exercising any right, power or privilege under this Agreement or the
documents referred to in this Agreement will operate as a waiver of such right,
power or privilege, and no single or partial exercise of any such right, power
or privilege will preclude any other or further exercise of such right, power or
privilege or the exercise of any other right, power or privilege.

                  12.10.   DISCLOSURE SCHEDULES

                  In the event of any inconsistency between the statements in
the body of this Agreement and those in the Security Disclosure Schedule (other
than an exception expressly set forth as such in the Security Disclosure
Schedule with respect to a specifically identified representation or warranty),
the statements in the body of this Agreement will control.

                  12.11.   NO THIRD-PARTY RIGHTS

                  Except as specifically set forth herein, nothing expressed or
referred to in this Agreement will be construed to give any person other than
the parties to this Agreement any legal or equitable right, remedy or claim
under or with respect to this Agreement or any provision of this Agreement. This
Agreement and all of its provisions and conditions are for the sole and
exclusive benefit of the parties to this Agreement and their successors and
assigns.

                  12.12.   WAIVER OF JURY TRIAL

                  Each of the parties hereto irrevocably waives any and all
right to trial by jury in any legal proceeding arising out of or related to this
Agreement or the transactions contemplated hereby.

                  12.13.   SEVERABILITY

                  If any provision of this Agreement is held invalid or
unenforceable by any court of competent jurisdiction, the other provisions of
this Agreement will remain in full force and effect. Any provision of this
Agreement held invalid or unenforceable only in part or degree will remain in
full force and effect to the extent not held invalid or unenforceable.


                                      -65-
<PAGE>   162


                  IN WITNESS WHEREOF, this Agreement and Plan of Merger has been
executed on behalf of Park National Corporation and Security Banc Corporation to
be effective as of the date set forth in the first paragraph above.

ATTEST:                             PARK NATIONAL CORPORATION


 /s/ David C. Bowers                By:  /s/ C. Daniel DeLawder
----------------------------            -----------------------

                                    Printed Name:  C. Daniel DeLawder
                                    Title: President and Chief Executive Officer


ATTEST:                             SECURITY BANC CORPORATION



 /s/ J. William Stapleton           By: /s/ Harry O. Egger
----------------------------           -------------------

                                    Printed Name:  Harry O. Egger
                                    Title: Chairman of the Board, President
                                           and Chief Executive Officer


                                      -66-
<PAGE>   163



                                    EXHIBIT A
                         TO AGREEMENT AND PLAN OF MERGER

November 20, 2000


Park National Corporation
50 North Third Street
Newark, Ohio 43058-3500
Attention:   C. Daniel DeLawder, President
             and Chief Executive Officer

Gentlemen:

         I have been advised that, as of the date hereof, I may be deemed to be
an "affiliate" of Security Banc Corporation, an Ohio corporation ("Security"),
as the term "affiliate" is (i) defined for purposes of paragraphs (c) and (d) of
Rule 145 of the Rules and Regulations (the "Rules and Regulations") of the
Securities and Exchange Commission (the "Commission") under the Securities Act
of 1933, as amended (the "Securities Act"), and/or (ii) used in and for purposes
of Accounting Series, Releases 130 and 135, as amended, of the Commission.
Pursuant to the terms of the Agreement and Plan of Merger, dated as of November
20, 2000 (the "Merger Agreement"), by and between Security and Park National
Corporation, an Ohio corporation ("Park"), Security will be merged (the
"Merger") with and into Park and the name of the surviving corporation will be
Park National Corporation, an Ohio corporation (the "Surviving Corporation").

         As used herein, "Security Common Shares" means the Common Shares, par
value $1.5625 per share, of Security and "Surviving Corporation Common Shares"
means the Common Shares, without par value, of the Surviving Corporation.

         I represent, warrant and covenant to the Surviving Corporation that in
the event I receive any Surviving Corporation Common Shares as a result of the
Merger:

                  A. I shall not make any sale, transfer or other disposition of
         any Surviving Corporation Common Shares (including any securities which
         may be paid as a dividend or otherwise distributed thereon or received
         pursuant to the exercise of stock options) acquired by me in the Merger
         in violation of the 1933 Act or the Rules and Regulations.

                  B. I have carefully read this letter and the Agreement and
         discussed their requirements and other applicable limitations upon my
         ability to sell, transfer or otherwise dispose of Surviving Corporation
         Common Shares (including any securities which may be paid as a dividend
         or otherwise distributed thereon or received pursuant to the exercise
         of stock options) to the extent I felt necessary, with my counsel or
         counsel for Security.



<PAGE>   164


                  C. I have been advised that the issuance of Surviving
         Corporation Common Shares to me pursuant to the Merger has been or will
         be registered with the Commission under the 1933 Act on a Registration
         Statement on Form S-4. However, I have also been advised that, because
         at the time the Merger will be submitted for a vote of the shareholders
         of Security, I may be deemed to be an affiliate of Security, the
         distribution by me of any Surviving Corporation Common Shares acquired
         by me in the Merger will not be registered under the 1933 Act and that
         I may not sell, transfer or otherwise dispose of any Surviving
         Corporation Common Shares (including any securities which may be paid
         as a dividend or otherwise distributed thereon or received pursuant to
         the exercise of stock options) acquired by me in the Merger unless (i)
         such sale, transfer or other disposition has been registered under the
         1933 Act, (ii) such sale, transfer or other disposition is made in
         conformity with the volume and other limitations of Rule 145
         promulgated by the Commission under the 1933 Act, or (iii) in the
         opinion of counsel reasonably acceptable to the Surviving Corporation,
         such sale, transfer or other disposition is otherwise exempt from
         registration under the 1933 Act.

                  D. I understand that the Surviving Corporation is under no
         obligation to register under the 1933 Act the sale, transfer or other
         disposition by me or on my behalf of any Surviving Corporation Common
         Shares acquired by me in the Merger or to take any other action
         necessary in order to make an exemption from such registration
         available.

                  E. I also understand that stop transfer instructions will be
         given to the Surviving Corporation's transfer agent with respect to
         Surviving Corporation Common Shares (including any securities which may
         be paid as a dividend or otherwise distributed thereon or received
         pursuant to the exercise of stock options) and that there will be
         placed on the certificates for the Surviving Corporation Common Shares
         acquired by me in the Merger, or any substitutions therefor, a legend
         stating in substance:

                  "The common shares represented by this certificate were issued
                  in a transaction to which Rule 145 promulgated under the
                  Securities Act of 1933 applies. The common shares represented
                  by this certificate may only be transferred in accordance with
                  the terms of an agreement dated November 20, 2000 between the
                  registered holder hereof and the issuer of the certificate, a
                  copy of which agreement will be mailed to the holder hereof
                  without charge within five days after receipt of written
                  request therefor."

                  F. I also understand that unless the transfer by me of my
         Surviving Corporation Common Shares has been registered under the 1933
         Act or is a sale made in conformity with the provisions of Rule 145,
         the Surviving Corporation reserves the right to put the following
         legend on the certificates issued to my transferee:

                  "The common shares represented by this certificate have not
                  been registered under the Securities Act of 1933 and were
                  acquired from a person who received such common shares in a
                  transaction to which Rule 145 promulgated under the Securities
                  Act of 1933 applies. The





                                      -2-
<PAGE>   165

                  common shares may not be sold, pledged or otherwise
                  transferred except in accordance with an exemption from the
                  registration requirements of the Securities Act of 1933."

         It is understood and agreed that the legends set forth in paragraphs E
and F above shall be removed by delivery of substitute certificates without such
legends if the undersigned shall have delivered to the Surviving Corporation a
copy of a letter from the staff of the Commission, or an opinion of counsel in
form and substance reasonably satisfactory to the Surviving Corporation, to the
effect that such legends are not required for purposes of the 1933 Act.

         I further represent to and covenant with Security and the Surviving
Corporation that I will not, within the 30 days prior to the Effective Time (as
defined in the Agreement), sell, transfer or otherwise dispose of any Security
Common Shares and that I will not sell, transfer or otherwise dispose of any
Surviving Corporation Common Shares (whether or not acquired by me in the
Merger) until after such time as results covering at least 30 days of
post-Merger combined operations of Security and Park have been published by the
Surviving Corporation, in the form of a quarterly earnings report, an effective
registration statement filed with the Commission, a report to the Commission on
Form 10-K, 10-Q or 8-K, or any other public filing or announcement which
includes the combined results of operations. Furthermore, I understand that
Security and the Surviving Corporation will give stop transfer instructions to
their respective transfer agents in order to prevent the breach of the
representations, warranties and covenants made by me in this paragraph. I also
understand that the Merger is intended to be treated for accounting purposes as
a "pooling-of-interests," and I agree that, if Security or the Surviving
Corporation advises me in writing that additional restrictions apply to my
ability to sell, transfer or otherwise dispose of Security Common Shares or
Surviving Corporation Common Shares in order to be entitled to use the
"pooling-of-interests" accounting method, I will abide by such restrictions.

                                         Very truly yours,




                                         ---------------------------------------
                                         Printed Name:
                                                      --------------------------

Accepted this _____ day of
____________, 2000

By:
    ---------------------------
Printed Name:
             ------------------
Title:
      -------------------------


                                      -3-
<PAGE>   166



                      EXHIBITS AND DISCLOSURE SCHEDULES TO
                          AGREEMENT AND PLAN OF MERGER,
                         DATED AS OF NOVEMBER 20, 2000,
                                 BY AND BETWEEN
                            PARK NATIONAL CORPORATION
                                       AND
                            SECURITY BANC CORPORATION



1.       Exhibit A - Form of Affiliate Letter Restricting Resale of Securities


2.       Representations and Warranties Disclosure Schedule of Security Banc
         Corporation

3.       Updated Representations and Warranties Disclosure Schedule of Security
         Banc Corporation.

The above-described Schedules are not being filed herewith. Park National
Corporation agrees to furnish supplementally to the Securities and Exchange
Commission a copy of any omitted Schedule upon request.




<PAGE>   167
                    [Letterhead of Austin Associates, Inc.]

                                                                      APPENDIX B



November 20, 2000


CONFIDENTIAL

Board of Directors
Security Banc Corporation
40 South Limestone Street
Springfield, OH  45502

Members of the Board:

You have requested our opinion as to the fairness, from a financial point of
view, to Security Banc Corporation ("Security") of the terms of the Agreement
and Plan of Merger dated as of November 20, 2000 ("Agreement") between Security
and Park National Corporation, Newark, Ohio ("Park"). The Agreement provides for
a merger of Security with and into Park, with Park being the surviving
corporation.

The terms of the Agreement provide for the issuance of 3,350,000 shares of Park
common stock to Security common stockholders. Based on Security's current
outstanding common shares, the exchange ratio equals .2844. The Agreement
further provides that stock options previously granted by Security be converted
into and become options to purchase Park common stock. Security's Board may
terminate the transaction if the Park Average Closing Price (as defined in the
Agreement) is less than $77.50.

In carrying out our engagement, we have reviewed and analyzed material bearing
upon the financial and operating condition of Security and Park, including but
not limited to the following: (i) the Agreement; (ii) the audited financial
statements of Security and Park for the period 1995 through 1999; (iii)
unaudited financial statements of Security and Park for the period ending
September 30, 2000; (iv) certain other publicly available information regarding
Security and Park; (v) publicly available information regarding the performance
of certain other companies whose business activities were believed by Austin
Associates to be generally comparable to those of Security and Park; (vi) the
financial terms, to the extent publicly available, of certain comparable
transactions; and (vii) such other analysis and information as we deemed
relevant.

In our review and analysis, we relied upon and assumed the accuracy and
completeness of the financial and other information provided to us or publicly
available, and have not attempted to verify the same. We have made no
independent verification as to the status of individual loans made by Security
or Park, and have instead relied upon representations and information concerning
loans of Security and Park in the aggregate. In rendering our opinion, we have
assumed that the transaction will be a tax-free reorganization with no material
adverse tax consequences to Security or Park, or to Security shareholders
receiving Park stock. In addition, we have assumed in the course of obtaining
the necessary approvals for the transaction, no condition will be imposed that
will have a material adverse effect on the contemplated benefits of the
transaction to Security and its shareholders.

Based upon our analysis and subject to the qualifications described herein, we
believe that as of the date of this letter, the terms of the Agreement are fair,
from a financial point of view, to Security and its shareholders.

Austin Associates reserves the right to review all disclosures in the proxy
materials and consent to the characterization of our fairness opinion. For our
services in rendering this opinion, Security will pay us a fee and indemnify us
against certain liabilities.

/s/ Austin Associates, Inc.
AUSTIN ASSOCIATES, INC.




                                       B-1
<PAGE>   168



                                                                      APPENDIX C

                        OHIO REVISED CODE SECTION 1701.85
          DISSENTING SHAREHOLDER'S DEMAND FOR FAIR CASH VALUE OF SHARES

        (A)(1)  A shareholder of a domestic corporation is entitled to relief as
a dissenting shareholder in respect of the proposals described in sections
1701.74, 1701.76, and 1701.84 of the Revised Code, only in compliance with this
section.

        (2)     If the proposal must be submitted to the shareholders of the
corporation involved, the dissenting shareholder shall be a record holder of the
shares of the corporation as to which he seeks relief as of the date fixed for
the determination of shareholders entitled to notice of a meeting of the
shareholders at which the proposal is to be submitted, and such shares shall not
have been voted in favor of the proposal. Not later than ten days after the date
on which the vote on the proposal was taken at the meeting of the shareholders,
the dissenting shareholder shall deliver to the corporation a written demand for
payment to him of the fair cash value of the shares as to which he seeks relief,
which demand shall state his address, the number and class of such shares, and
the amount claimed by him as the fair cash value of the shares.

        (3)     The dissenting shareholder entitled to relief under division (C)
of section 1701.84 of the Revised Code in the case of a merger pursuant to
section 1701.80 of the Revised Code and a dissenting shareholder entitled to
relief under division (E) of section 1701.84 of the Revised Code in the case of
a merger pursuant to section 1701.801 [1701.80.1] of the Revised Code shall be a
record holder of the shares of the corporation as to which he seeks relief as of
the date on which the agreement of merger was adopted by the directors of that
corporation. Within twenty days after he has been sent the notice provided in
section 1701.80 or 1701.801 [1701.80.1] of the Revised Code, the dissenting
shareholder shall deliver to the corporation a written demand for payment with
the same information as that provided for in division (A)(2) of this section.

        (4)     In the case of a merger or consolidation, a demand served on the
constituent corporation involved constitutes service on the surviving or the new
entity, whether the demand is served before, on, or after the effective date of
the merger or consolidation.

        (5)     If the corporation sends to the dissenting shareholder, at the
address specified in his demand, a request for the certificates representing the
shares as to which he seeks relief, the dissenting shareholder, within fifteen
days from the date of the sending of such request, shall deliver to the
corporation the certificates requested so that the corporation may forthwith
endorse on them a legend to the effect that demand for the fair cash value of
such shares has been made. The corporation promptly shall return such endorsed
certificates to the dissenting shareholder. A dissenting shareholder's failure
to deliver such certificates terminates his rights as a dissenting shareholder,
at the option of the corporation, exercised by written notice sent to the
dissenting shareholder within twenty days after the lapse of the fifteen-day
period, unless a court for good cause shown otherwise directs. If shares
represented by a certificate on which such a legend has been endorsed are
transferred, each new certificate issued for them shall bear a similar legend,
together with the name of the original dissenting holder of such shares. Upon
receiving a demand for payment from a dissenting shareholder who is the record
holder of uncertificated securities, the corporation shall make an appropriate
notation of the demand for payment in its shareholder records. If uncertificated
shares for which payment has been demanded are to be transferred, any new
certificate issued for the shares shall bear the legend required for
certificated securities as provided in this paragraph. A transferee of the
shares so endorsed, or of uncertificated securities where such notation has been
made, acquires only such rights in the corporation as the original dissenting
holder of such shares had immediately after the service of a demand for payment
of the fair cash value of the shares. A request under this paragraph by the
corporation is not an admission by the corporation that the shareholder is
entitled to relief under this section.

        (B)     Unless the corporation and the dissenting shareholder have come
to an agreement on the fair cash value per share of the shares as to which the
dissenting shareholder seeks relief, the dissenting shareholder or the
corporation, which in case of a merger or consolidation may be the surviving or
new entity, within three months after the service of the demand by the
dissenting shareholder, may file a complaint in the court of common pleas of the
county in which the principal office of the corporation that issued the shares
is located or was located when the


                                      C-1
<PAGE>   169

proposal was adopted by the shareholders of the corporation, or, if the proposal
was not required to be submitted to the shareholders, was approved by the
directors. Other dissenting shareholders, within that three-month period, may
join as plaintiffs or may be joined as defendants in any such proceeding, and
any two or more such proceedings may be consolidated. The complaint shall
contain a brief statement of the facts, including the vote and the facts
entitling the dissenting shareholder to the relief demanded. No answer to such a
complaint is required. Upon the filing of such a complaint, the court, on motion
of the petitioner, shall enter an order fixing a date for a hearing on the
complaint and requiring that a copy of the complaint and a notice of the filing
and of the date for hearing be given to the respondent or defendant in the
manner in which summons is required to be served or substituted service is
required to be made in other cases. On the day fixed for the hearing on the
complaint or any adjournment of it, the court shall determine from the complaint
and from such evidence as is submitted by either party whether the dissenting
shareholder is entitled to be paid the fair cash value of any shares and, if so,
the number and class of such shares. If the court finds that the dissenting
shareholder is so entitled, the court may appoint one or more persons as
appraisers to receive evidence and to recommend a decision on the amount of the
fair cash value. The appraisers have such power and authority as is specified in
the order of their appointment. The court thereupon shall make a finding as to
the fair cash value of a share and shall render judgment against the corporation
for the payment of it, with interest at such rate and from such date as the
court considers equitable. The costs of the proceeding, including reasonable
compensation to the appraisers to be fixed by the court, shall be assessed or
apportioned as the court considers equitable. The proceeding is a special
proceeding and final orders in it may be vacated, modified, or reversed on
appeal pursuant to the Rules of Appellate Procedure and, to the extent not in
conflict with those rules, Chapter 2505 of the Revised Code. If, during the
pendency of any proceeding instituted under this section, a suit or proceeding
is or has been instituted to enjoin or otherwise to prevent the carrying out of
the action as to which the shareholder has dissented, the proceeding instituted
under this section shall be stayed until the final determination of the other
suit or proceeding. Unless any provision in division (D) of this section is
applicable, the fair cash value of the shares that is agreed upon by the parties
or fixed under this section shall be paid within thirty days after the date of
final determination of such value under this division, the effective date of the
amendment to the articles, or the consummation of the other action involved,
whichever occurs last. Upon the occurrence of the last such event, payment shall
be made immediately to a holder of uncertificated securities entitled to such
payment. In the case of holders of shares represented by certificates, payment
shall be made only upon and simultaneously with the surrender to the corporation
of the certificates representing the shares for which the payment is made.

        (C)     If the proposal was required to be submitted to the shareholders
of the corporation, fair cash value as to those shareholders shall be determined
as of the day prior to the day on which the vote by the shareholders was taken
and, in the case of a merger pursuant to section 1701.80 or 1701.801 [1701.80.1]
of the Revised Code, fair cash value as to shareholders of a constituent
subsidiary corporation shall be determined as of the day before the adoption of
the agreement of merger by the directors of the particular subsidiary
corporation. The fair cash value of a share for the purposes of this section is
the amount that a willing seller who is under no compulsion to sell would be
willing to accept and that a willing buyer who is under no compulsion to
purchase would be willing to pay, but in no event shall the fair cash value of a
share exceed the amount specified in the demand of the particular shareholder.
In computing such fair cash value, any appreciation or depreciation in market
value resulting from the proposal submitted to the directors or to the
shareholders shall be excluded.

        (D)(1)  The right and obligation of a dissenting shareholder to receive
such fair cash value and to sell such shares as to which he seeks relief, and
the right and obligation of the corporation to purchase such shares and to pay
the fair cash value of them terminates if any of the following applies:

        (a)     The dissenting shareholder has not complied with this section,
unless the corporation by its directors waives such failure;

        (b)     The corporation abandons the action involved or is finally
enjoined or prevented from carrying it out, or the shareholders rescind their
adoption of the action involved;

        (c)     The dissenting shareholder withdraws his demand, with the
consent of the corporation by its directors;

                                      C-2
<PAGE>   170

        (d)     The corporation and the dissenting shareholder have not come to
an agreement as to the fair cash value per share, and neither the shareholder
nor the corporation has filed or joined in a complaint under division (B) of
this section within the period provided in that division.

        (2)     For purposes of division (D)(1) of this section, if the merger
or consolidation has become effective and the surviving or new entity is not a
corporation, action required to be taken by the directors of the corporation
shall be taken by the general partners of a surviving or new partnership or the
comparable representatives of any other surviving or new entity.

        (E)     From the time of the dissenting shareholder's giving of the
demand until either the termination of the rights and obligations arising from
it or the purchase of the shares by the corporation, all other rights accruing
from such shares, including voting and dividend or distribution rights, are
suspended. If during the suspension, any dividend or distribution is paid in
money upon shares of such class or any dividend, distribution, or interest is
paid in money upon any securities issued in extinguishment of or in substitution
for such shares, an amount equal to the dividend, distribution, or interest
which, except for the suspension, would have been payable upon such shares or
securities, shall be paid to the holder of record as a credit upon the fair cash
value of the shares. If the right to receive fair cash value is terminated other
than by the purchase of the shares by the corporation, all rights of the holder
shall be restored and all distributions which, except for the suspension, would
have been made shall be made to the holder of record of the shares at the time
of termination.


                                      C-3
<PAGE>   171



                                     PART II

                   INFORMATION NOT REQUIRED IN THE PROSPECTUS

ITEM 20. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         The regulations of Park provide that Park will indemnify its directors
or officers against expenses (including attorney's fees, filing fees, court
reporter's fees and transcript costs), judgments, fines and amounts paid in
settlement by reason of the fact that they are or were directors, officers,
employees or agents of Park or, at the request of Park, were serving another
entity in a similar capacity. In order to receive indemnification, the directors
or officers must have acted in good faith and in a manner they reasonably
believed to be in the best interests of Park. With regard to criminal matters,
Park will indemnify directors and officers if the directors or officers had no
reasonable cause to believe their conduct was unlawful. Directors or officers
claiming indemnification will be presumed to have acted in good faith and in a
manner they reasonably believed to be not opposed to the best interests of Park
and, with respect to any criminal matter, to have had no reasonable cause to
believe their conduct was unlawful.

         Park will not indemnify any officer or director of Park who was a party
to any completed action or suit instituted by, or in the right of, Park for any
matter asserted in the action as to which the officer or director has been
adjudged to be liable for acting with reckless disregard for the best interests
of Park or misconduct, other than negligence, in the performance of his duty to
Park. If, however, the Court of Common Pleas of Licking County, Ohio or the
court in which the action was brought determines that the officer or director is
fairly and reasonably entitled to indemnity, Park must indemnify the officer or
director to the extent permitted by the court.

         Park will make any indemnification not precluded by Park's regulations
only upon a determination that the director or officer has met the applicable
standard of conduct. The determination may be made only by a majority vote of a
quorum of disinterested directors; if a quorum is not obtainable or if a
majority of a quorum of disinterested directors so directs, in a written opinion
by independent legal counsel; by the shareholders; or by the Court of Common
Pleas of Licking County, Ohio or the court, if any, in which the action was
brought.

         Park will pay expenses incurred in defending any action, suit or
proceeding in advance upon receipt of an undertaking by or on behalf of the
director or officer to repay that amount if the director or officer is not
entitled to be indemnified by Park.

         The regulations of Park state that the indemnification provided by the
regulations is not exclusive of any other rights to which any person seeking
indemnification may be entitled. Additionally, the Park regulations provide that
Park may purchase and maintain insurance on behalf of any person who is or was a
director, officer, employee or agent of Park, or who is or was serving another
entity at the request of Park, against any liability asserted against him and
incurred by him in that capacity, or arising out of his status as such, whether
or not Park would have the obligation or power to indemnify him under the Park
regulations. Park has purchased and maintains those policies.

ITEM 21. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.

(a)      EXHIBITS.

    2.1     Agreement and Plan of Merger (excluding exhibits and schedules),
            dated as of November 20, 2000, by and between Park National
            Corporation ("Park") and Security Banc Corporation ("Security")
            (included in the joint proxy statement/prospectus as part of
            Appendix A)

    3.1     Articles of Incorporation of Park as filed with the Ohio Secretary
            of State on March 24, 1992 (incorporated herein by reference to
            Exhibit 3(a) to Park's Form 8-B, filed on May 20, 1992 (File No.
            0-18772) ("Park's Form 8-B"))

                                      II-1
<PAGE>   172

    3.2     Certificate of Amendment to the Articles of Incorporation of Park as
            filed with the Ohio Secretary of State on May 6, 1993 (incorporated
            herein by reference to Exhibit 3(b) to Park's Annual Report on Form
            10-K for the fiscal year ended December 31, 1993 (File No. 0-18772))

    3.3     Certificate of Amendment to the Articles of Incorporation of Park as
            filed with the Ohio Secretary of State on April 16, 1996
            (incorporated herein by reference to Exhibit 3(a) to Park's
            Quarterly Report on Form 10-Q for the fiscal quarter ended March 31,
            1996 (File No. 1-13006))

    3.4     Certificate of Amendment by Shareholders to the Articles of
            Incorporation of Park as filed with the Ohio Secretary of State on
            April 22, 1997 (incorporated herein by reference to Exhibit 3(a)(1)
            to Park's Quarterly Report on Form 10-Q for the fiscal quarter ended
            June 30, 1997 (File No. 1-13006)("Park's June 1997 Form 10-Q"))

    3.5     Articles of Incorporation of Park (reflecting amendments through
            April 22, 1997) (for SEC reporting compliance purposes only - not
            filed with Ohio Secretary of State (incorporated herein by reference
            to Exhibit 3(a)(2) to Park's June 1997 Form 10-Q)

    3.6     Regulations of Park (incorporated herein by reference to Exhibit
            3(b) to Park's Form 8-B)

    3.7     Certified Resolution regarding adoption of amendment to Subsection
            2.02(A) of the Regulations of Park by Shareholders on April 22, 1997
            (incorporated herein by reference to Exhibit 3(b)(1) to Park's June
            1997 Form 10-Q)

    3.8     Regulations of Park (reflecting amendments through April 22, 1997)
            (for SEC reporting compliance purposes only) (incorporated herein by
            reference to Exhibit 3(b)(2) to Park's June 1997 Form 10-Q)

      5     Opinion of Vorys, Sater, Seymour and Pease LLP, counsel to Park, as
            to the legality of the securities being issued

     *8     Opinion of Vorys, Sater, Seymour and Pease LLP, counsel to Park, as
            to tax matters

   10.1     Summary of Incentive Bonus Plan of Park (incorporated herein by
            reference to Exhibit 10.1 to Park's Registration Statement on Form
            S-4 filed February 22, 2000 (Registration No. 333-30858) ("Park's
            February 2000 Form S-4"))

   10.2     Split-Dollar Agreement, dated May 17, 1993, between William T.
            McConnell and The Park National Bank (incorporated herein by
            reference to Exhibit 10(f) to Park's Annual Report on Form 10-K for
            the fiscal year ended December 31, 1993 (File No. 0-18772)); and
            Schedule A identifying other identical Split-Dollar Agreements
            between subsidiaries of Park and executive officers of such
            subsidiaries who are directors or executive officers of Park
            (incorporated herein by reference to Exhibit 10.2 to Park's February
            2000 Form S-4)

   10.3     Split-Dollar Agreement dated September 29, 1993, between Dominic C.
            Fanello and The Richland Trust Company (incorporated herein by
            reference to Exhibit 10(g) to Park's Annual Report on Form 10-K for
            the fiscal year ended December 31, 1993 (File No. 0-18772)); and
            Schedule A identifying other identical Split-Dollar Agreements
            between directors of Park National and The Park National Bank, The
            Richland Trust Company, Century National Bank or The First-Knox
            National Bank of Mount Vernon as identified in such Schedule A
            (incorporated herein by reference to Exhibit 10.3 to Park's February
            2000 Form S-4)

                                      II-2
<PAGE>   173

   10.4     Park National Corporation 1995 Incentive Stock Option Plan (as
            amended through April 20, 1998) (incorporated herein by reference to
            Exhibit 10 to Park's Registration Statement on Form S-8 filed May
            14, 1998 (Registration No. 333-52653))

   10.5     Form of Stock Option Agreement executed in connection with the grant
            of options under the Park National Corporation 1995 Incentive Stock
            Option Plan, as amended (incorporated herein by reference to Exhibit
            10(i) to Park's Annual Report on Form 10-K for the fiscal year ended
            December 31, 1998 (File No. 1-13006))

   10.6     Description of Park National Corporation Supplemental Executive
            Retirement Plan (incorporated herein by reference to Exhibit 10(i)
            to Park's Registration Statement on Form S-4, filed on January 24,
            1997 (Registration No. 333-20417))

     21     Subsidiaries of Park

   23.1     Consent of Vorys, Sater, Seymour and Pease LLP with respect to its
            opinion relating to the legality of the securities being issued
            (included in Exhibit 5)

  *23.2     Consent of Vorys, Sater, Seymour and Pease LLP with respect to its
            tax opinion (included in Exhibit 8)

   23.3     Consent of Ernst & Young LLP (with respect to Park)

   23.4     Consent of Ernst & Young LLP (with respect to Security)

   23.5     Consent of Austin Associates, Inc., financial advisors to Security

     24     Powers of Attorney of Directors and Executive Officers of Park
            authorizing the signing of their names to this Registration
            Statement and any and all amendments to this Registration Statement
            and other documents submitted in connection herewith

   99.1     Form of Fairness Opinion of Austin Associates, Inc. (set forth in
            Appendix B to the joint proxy statement/prospectus included in this
            Registration Statement)

   99.2     Form of Notice of Special Meeting of Shareholders of Security (set
            forth following the cover page of this Registration Statement)

   99.3     Form of Proxy to be used in connection with Special Meeting of
            Shareholders of Security

  *99.4     Form of Letter to be Sent to Shareholders of Security

   99.5     Form of Notice of Special Meeting of Shareholders of Park (set forth
            immediately following the cover page of this Registration Statement)

   99.6     Form of Proxy to be used in connection with Special Meeting of
            Shareholders of Park

  *99.7     Form of Letter to be Sent to Shareholders of Park


    --------------------

    *   To be filed by amendment


                                      II-3
<PAGE>   174

(b)      FINANCIAL STATEMENT SCHEDULES.

         All supporting schedules have been omitted because they are not
required.

ITEM 22. UNDERTAKINGS.

(A)      The undersigned Registrant hereby undertakes:

         (1)     To file, during any period in which offers or sales are being
made, a post-effective amendment to this Registration Statement:

                 (i)      To include any prospectus required by Section 10(a)(3)
         of the Securities Act of 1933;

                 (ii)     To reflect in the prospectus any facts or events
         arising after the effective date of the Registration Statement (or the
         most recent post-effective amendment thereof) which, individually or in
         the aggregate, represent a fundamental change in the information set
         forth in the Registration Statement. Notwithstanding the foregoing, any
         increase or decrease in volume of securities offered (if the total
         dollar value of securities offered would not exceed that which was
         registered) and any deviation from the low or high end of the estimated
         maximum offering range may be reflected in the form of prospectus filed
         with the Commission pursuant to Rule 424(b) if, in the aggregate, the
         changes in volume and price represent no more than a 20% change in the
         maximum aggregate offering price set forth in the "Calculation of
         Registration Fee" table in the effective Registration Statement;

                 (iii)    To include any material information with respect to
         the plan of distribution not previously disclosed in the Registration
         Statement or any material change to such information in the
         Registration Statement;

         (2)     That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

         (3)     To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

(B)      The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
Registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Securities Exchange Act of
1934) that is incorporated by reference in the Registration Statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.

(C)      The undersigned Registrant hereby undertakes:

         (1)     That, prior to any public reoffering of the securities
registered hereunder through use of a prospectus which is a part of this
Registration Statement, by any person or party who is deemed to be an
underwriter within the meaning of Rule 145(c), the issuer undertakes that such
reoffering prospectus will contain the information called for by the applicable
registration form with respect to reofferings by persons who may be deemed
underwriters, in addition to the information called for by the other items of
the applicable form.

         (2)     That every prospectus (i) that is filed pursuant to paragraph
(1) immediately preceding, or (ii) that purports to meet the requirements of
Section 10(a)(3) of the Act and is used in connection with an offering of
securities subject to Rule 415, will be filed as a part of an amendment to the
Registration Statement and will not be used until such amendment is effective,
and that, for purposes of determining any liability under the Securities Act of
1933, each such post-effective amendment shall be deemed to be a new
registration statement relating to the

                                      II-4
<PAGE>   175

securities offered therein, and the offering of such securities at that time
shall be deemed to be the initial bona fide offering thereof.

(D)      Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.

(E)      The undersigned Registrant hereby undertakes:

         (1)     To respond to requests for information that is incorporated by
reference into the prospectus pursuant to Items 4, 10(b), 11, or 13 of this Form
S-4, within one business day of receipt of such request, and to send the
incorporated documents by first class mail or other equally prompt means. This
includes information contained in the documents filed subsequent to the
effective date of the Registration Statement through the date of responding to
the request.

         (2)     To supply by means of a post-effective amendment all
information concerning a transaction, and the company being acquired involved
therein, that was not the subject of and included in the Registration Statement
when it became effective.


                                      II-5
<PAGE>   176


                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, the
Registrant has duly caused this Registration Statement on Form S-4 to be signed
on its behalf by the undersigned, thereunto duly authorized, in the City of
Newark, State of Ohio, on the 29th day of December, 2000.

                                    PARK NATIONAL CORPORATION


                                    By:  /s/ C. Daniel DeLawder
                                       ----------------------------------------
                                       C. Daniel DeLawder
                                       Chief Executive Officer and President

        Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement on Form S-4 has been signed by the following persons in
the capacities indicated below on the 29th day of December, 2000.

<TABLE>
<CAPTION>
               NAME                                TITLE
               ----                                -----

<S>                                             <C>
                 *                                 Chairman of the Board and Director
------------------------------------
William T. McConnell


   /s/ C. Daniel DeLawder                          President, Chief Executive Officer and
------------------------------------               Director (Principal Executive Officer)
C. Daniel DeLawder


                 *                                 Chief Financial Officer and Principal
------------------------------------               Accounting Officer
John W. Kozak


                 *                                 Director
------------------------------------
Maureen Buchwald


                 *                                 Director
------------------------------------
James J. Cullers


                 *                                 Director
------------------------------------
D. C. Fanello


                 *                                 Director
------------------------------------
R. William Geyer


                 *                                 Director
------------------------------------
Philip H. Jordan, Jr., Ph.D.


                 *                                 Director
------------------------------------
Howard E. LeFevre
</TABLE>


                                      II-6


<PAGE>   177



                 *                                 Director
------------------------------------
Phillip T. Leitnaker


                 *                                 Director
------------------------------------
James A. McElroy


                 *                                 Director
------------------------------------
John J. O'Neill


                 *                                 Director
------------------------------------
William A. Phillips


                 *                                 Director
------------------------------------
J. Gilbert Reese


                 *                                 Director
------------------------------------
Rick R. Taylor


                 *                                 Director
------------------------------------
John L. Warner


---------------------

*By C. Daniel DeLawder pursuant to Power of Attorney executed by the directors
and executive officers listed above, which Power of Attorney has been filed with
the Securities and Exchange Commission.



  /s/ C. Daniel DeLawder
---------------------------------------------
C. Daniel DeLawder
President and Chief Executive Officer



                                      II-7

<PAGE>   178




                                  EXHIBIT INDEX

<TABLE>
<CAPTION>
EXHIBIT NO.                             DESCRIPTION OF EXHIBIT
-----------                             ----------------------

<S>             <C>
    2.1          Agreement and Plan of Merger (excluding exhibits and
                 schedules), dated as of November 20, 2000, by and between Park
                 National Corporation ("Park") and Security Banc Corporation
                 ("Security") (included in the joint proxy statement/prospectus
                 as part of Appendix A)

    3.1          Articles of Incorporation of Park as filed with the Ohio
                 Secretary of State on March 24, 1992 (incorporated herein by
                 reference to Exhibit 3(a) to Park's Form 8-B, filed on May 20,
                 1992 (File No. 0-18772) ("Park's Form 8-B"))

    3.2          Certificate of Amendment to the Articles of Incorporation of
                 Park as filed with the Ohio Secretary of State on May 6, 1993
                 (incorporated herein by reference to Exhibit 3(b) to Park's
                 Annual Report on Form 10-K for the fiscal year ended December
                 31, 1993 (File No. 0-18772))

    3.3          Certificate of Amendment to the Articles of Incorporation of
                 Park as filed with the Ohio Secretary of State on April 16,
                 1996 (incorporated herein by reference to Exhibit 3(a) to
                 Park's Quarterly Report on Form 10-Q for the fiscal quarter
                 ended March 31, 1996 (File No. 1-13006))

    3.4          Certificate of Amendment by Shareholders to the Articles of
                 Incorporation of Park as filed with the Ohio Secretary of State
                 on April 22, 1997 (incorporated herein by reference to Exhibit
                 3(a)(1) to Park's Quarterly Report on Form 10-Q for the fiscal
                 quarter ended June 30, 1997 (File No. 1-13006)("Park's June
                 1997 Form 10-Q"))

    3.5          Articles of Incorporation of Park (reflecting amendments
                 through April 22, 1997) (for SEC reporting compliance purposes
                 only - not filed with Ohio Secretary of State (incorporated
                 herein by reference to Exhibit 3(a)(2) to Park's June 1997 Form
                 10-Q)

    3.6          Regulations of Park (incorporated herein by reference to
                 Exhibit 3(b) to Park's Form 8-B)

    3.7          Certified Resolution regarding adoption of amendment to
                 Subsection 2.02(A) of the Regulations of Park by Shareholders
                 on April 22, 1997 (incorporated herein by reference to Exhibit
                 3(b)(1) to Park's June 1997 Form 10-Q)

    3.8          Regulations of Park (reflecting amendments through April 22,
                 1997) (for SEC reporting compliance purposes only)
                 (incorporated herein by reference to Exhibit 3(b)(2) to Park's
                 June 1997 Form 10-Q)

      5          Opinion of Vorys, Sater, Seymour and Pease LLP, counsel to
                 Park, as to the legality of the securities being issued

     *8          Opinion of Vorys, Sater, Seymour and Pease LLP, counsel to
                 Park, as to tax matters

   10.1          Summary of Incentive Bonus Plan of Park (incorporated herein by
                 reference to Exhibit 10.1 to Park's Registration Statement on
                 Form S-4 filed February 22, 2000 (Registration No. 333-30858)
                 ("Park's February 2000 Form S-4"))
</TABLE>



<PAGE>   179


<TABLE>
<CAPTION>
EXHIBIT NO.                             DESCRIPTION OF EXHIBIT
-----------                             ----------------------

<S>             <C>
   10.2          Split-Dollar Agreement, dated May 17, 1993, between William T.
                 McConnell and The Park National Bank (incorporated herein by
                 reference to Exhibit 10(f) to Park's Annual Report on Form 10-K
                 for the fiscal year ended December 31, 1993 (File No.
                 0-18772)); and Schedule A identifying other identical
                 Split-Dollar Agreements between subsidiaries of Park and
                 executive officers of such subsidiaries who are directors or
                 executive officers of Park (incorporated herein by reference to
                 Exhibit 10.2 to Park's February 2000 Form S-4)

   10.3          Split-Dollar Agreement dated September 29, 1993, between
                 Dominic C. Fanello and The Richland Trust Company (incorporated
                 herein by reference to Exhibit 10(g) to Park's Annual Report on
                 Form 10-K for the fiscal year ended December 31, 1993 (File No.
                 0-18772)); and Schedule A identifying other identical
                 Split-Dollar Agreements between directors of Park National and
                 The Park National Bank, The Richland Trust Company, Century
                 National Bank or The First-Knox National Bank of Mount Vernon
                 as identified in such Schedule A (incorporated herein by
                 reference to Exhibit 10.3 to Park's February 2000 Form S-4)

   10.4          Park National Corporation 1995 Incentive Stock Option Plan (as
                 amended through April 20, 1998) (incorporated herein by
                 reference to Exhibit 10 to Park's Registration Statement on
                 Form S-8 filed May 14, 1998 (Registration No. 333-52653))

   10.5          Form of Stock Option Agreement executed in connection with the
                 grant of options under the Park National Corporation 1995
                 Incentive Stock Option Plan, as amended (incorporated herein by
                 reference to Exhibit 10(i) to Park's Annual Report on Form 10-K
                 for the fiscal year ended December 31, 1998 (File No. 1-13006))

   10.6          Description of Park National Corporation Supplemental Executive
                 Retirement Plan (incorporated herein by reference to Exhibit
                 10(i) to Park's Registration Statement on Form S-4, filed on
                 January 24, 1997 (Registration No. 333-20417))

     21          Subsidiaries of Park

   23.1          Consent of Vorys, Sater, Seymour and Pease LLP with respect to
                 its opinion relating to the legality of the securities being
                 issued (included in Exhibit 5)

  *23.2          Consent of Vorys, Sater, Seymour and Pease LLP with respect to
                 its tax opinion (included in Exhibit 8)

   23.3          Consent of Ernst & Young LLP (with respect to Park)

   23.4          Consent of Ernst & Young LLP (with respect to Security)

   23.5          Consent of Austin Associates, Inc., financial advisors to
                 Security

     24          Powers of Attorney of Directors and Executive Officers of Park
                 authorizing the signing of their names to this Registration
                 Statement and any and all amendments to this Registration
                 Statement and other documents submitted in connection herewith

   99.1          Form of Fairness Opinion of Austin Associates, Inc. (set forth
                 in Appendix B to the joint proxy statement/prospectus included
                 in this Registration Statement)

   99.2          Form of Notice of Special Meeting of Shareholders of Security
                 (set forth following the cover page of this Registration
                 Statement)
</TABLE>



<PAGE>   180


<TABLE>
<CAPTION>
EXHIBIT NO.                             DESCRIPTION OF EXHIBIT
-----------                             ----------------------

<S>             <C>
   99.3          Form of Proxy to be used in connection with Special Meeting of
                 Shareholders of Security

  *99.4          Form of Letter to be Sent to Shareholders of Security

   99.5          Form of Notice of Special Meeting of Shareholders of Park (set
                 forth immediately following the cover page of this Registration
                 Statement)

   99.6          Form of Proxy to be used in connection with Special Meeting of
                 Shareholders of Park

  *99.7          Form of Letter to be Sent to Shareholders of Park
</TABLE>

    ---------------------

    *   To be filed by amendment




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