<PAGE>
 
EXHIBIT 10.1

                          AGREEMENT AND PLAN OF MERGER

          THIS AGREEMENT AND PLAN OF MERGER (hereinafter called "Agreement"),
made and entered into as of the 30th day of September, 1997, by and between
WESBANCO, INC., a West Virginia corporation, with its principal place of
business located at Bank Plaza, Wheeling, West Virginia (hereinafter called
"Wesbanco"), party of the first part, and COMMERCIAL BANCSHARES, INCORPORATED, a
West Virginia corporation, with its principal place of business located at 415
Market Street, Parkersburg, West Virginia, 26101,  (hereinafter called
"Commercial") party of the second part, and CBI HOLDING COMPANY (hereinafter
called "CBI"), a corporation to be formed under the laws of the State of West
Virginia by Wesbanco as its wholly-owned subsidiary solely for the purpose of
effecting the acquisition contemplated by this Agreement, party of the third
part, (effective as of its organization and execution of this Agreement).

          WHEREAS, Wesbanco is a West Virginia corporation duly organized and
validly existing under the laws of the State of West Virginia, and is a
registered bank holding company under the Bank Holding Company Act of 1956, as
amended, and

          WHEREAS, Commercial is a West Virginia corporation duly organized and
validly existing under the laws of the State of West Virginia, and is a
registered bank holding company under the Bank Holding Company Act of 1956, as
amended, which owns ten subsidiaries, namely, Commercial Banking and Trust
Company, Jackson County Bank, Farmers & Merchants Bank of Ritchie County, The
Dime Bank, Union Bank of Tyler County, The Community Bank, Bank of Paden City,
Hometown Finance Company, Hometown Insurance Agency, Inc. and CommBanc
Investments, Inc. (hereinafter collectively called "Subsidiaries"), and

          WHEREAS, CBI will be a corporation duly organized and validly existing
under the laws of the State of West Virginia which corporation shall be
organized to effect the terms and conditions of this Agreement, and

          WHEREAS, the Board of Directors of Wesbanco, by a majority vote of all
the members thereof, has approved this Agreement and has authorized the
execution hereof in counterparts and subject to the terms hereof will direct
that it be submitted to its shareholders; the Board of Directors of CBI shall,
prior to the execution hereof by CBI, have by a majority vote of all of the
members and shareholders thereof, approved this Agreement and authorized the
execution hereof in counterparts, all upon the issuance of CBI's charter as
hereinafter provided, and

          WHEREAS, Wesbanco desires to acquire Commercial and the Board of
Directors of Commercial has determined that, subject to all of the conditions of
this Agreement, including but not limited to the requirement that certain tax
rulings and fairness opinions be obtained, it would be in the best interests of
Commercial and its shareholders for Commercial to enter into this Agreement to
become affiliated with Wesbanco, and

          WHEREAS, it is proposed that Wesbanco, Commercial and CBI enter into
this Agreement whereby Commercial will merge with and into CBI and the
outstanding shares of common stock of Commercial ("Commercial Common Stock")
will be converted into shares of common stock of Wesbanco ("Wesbanco Common
Stock");

          NOW, THEREFORE, for and in consideration of the mutual promises and
covenants hereinafter set forth, and in accordance with the provisions of
applicable law, and intending to be legally bound hereby, the parties hereto do
hereby agree as follows:

                                   SECTION 1
                                      CBI
          1.1  Formation.  Wesbanco shall promptly cause CBI to be duly
organized as a business corporation under the laws of the State of West
Virginia.  CBI will be wholly-owned by Wesbanco at all times through the closing
of the transactions contemplated by this Agreement.

          1.2  Conduct of Business.  Wesbanco shall not permit CBI to conduct
any business operations other than such activities which are necessary to
consummate the merger contemplated in the Agreement (the "Merger").
<PAGE>
 
          1.3  Execution of Agreement.  Promptly after the organization of CBI,
Wesbanco shall cause CBI to take all necessary and proper action to ratify,
approve, adopt and execute the Agreement and to undertake the performance of all
of the terms and conditions of the Agreement to be performed by CBI.

          1.4  Voting of CBI Shares.  Promptly after the organization of CBI,
Wesbanco, as sole shareholder of CBI, shall vote all of the shares of CBI in
favor of the Merger.

                                   SECTION 2
                                   THE MERGER

          2.1  The Merger.  At the Effective Time (as defined in Section 2.5),
subject to the provisions of this Agreement, CBI shall merge with Commercial
(the "Merger"), under the charter of CBI.  CBI shall be the surviving
corporation (hereinafter sometimes called the "Surviving Corporation").

          2.2  Effect of Merger.  At the Effective Time, the corporate existence
of CBI, with all of its purposes, powers and objects, and all of its rights,
assets, liabilities and obligations, shall continue unaffected and unimpaired by
the Merger, and CBI as the Surviving Corporation shall continue to be governed
by the laws of the State of West Virginia.  CBI as the Surviving Corporation
shall also succeed to all of the rights, assets, liabilities and obligations of
Commercial in accordance with the West Virginia Corporation Act ("WVCA").  Upon
the Effective Date, (as defined in Section 11.5 hereof), the separate existence
and corporate organization of Commercial shall cease.

          2.3  Closing.  Wesbanco, Commercial and CBI will jointly request the
Secretary of State of West Virginia to issue a Certificate of Merger on the date
of the closing described in Section 11.4 hereof (the "Closing" and the "Closing
Date").

          2.4  Commercial's Obligations.  Commercial shall at any time, or from
time to time, as and when requested by the Surviving Corporation, or by its
successors and assigns, execute and deliver, or cause to be executed and
delivered in its name by its last acting officers, or by the corresponding
officers of the Surviving Corporation, all such conveyances, assignments,
transfers, deeds, or other instruments, and shall take or cause to be taken such
further or other action as the Surviving Corporation, its successors or assigns,
may deem necessary or desirable in order to evidence the transfer, vesting or
devolution of any property, right, privilege or franchise or to vest or perfect
in or confirm to the Surviving Corporation, its successors and assigns, title to
and possession of all the property, rights, privileges, powers, immunities,
franchises and interests referred to in this Agreement and otherwise to carry
out the intent and purposes hereof, all at the expense of the Surviving
Corporation.

          2.5  Articles of Merger.  Subject to the terms and conditions herein
provided, Articles of Merger, incorporating this Agreement, shall be executed to
comply with the applicable filing requirements of the WVCA at the Closing and on
the Closing Date.  On the Closing Date, such Articles of Merger shall be filed
with the Secretary of State of the State of West Virginia, who will duly issue a
Certificate of Merger.  The Surviving Corporation shall record said Certificate
of Merger in the office of the Clerk of the County Commission of Wood County.
The Merger shall become effective on the date (the "Effective Date") and at the
time (which time is hereinafter called the "Effective Time") when such
Certificate of Merger is issued by the Secretary of State.

                                   SECTION 3
                           ARTICLES OF INCORPORATION;
                    BYLAWS; BOARD OF DIRECTORS AND OFFICERS

          3.1  CBI Corporation.  The Articles of Incorporation of CBI, as
organized, shall constitute the Articles of Incorporation of the Surviving
Corporation.  The Bylaws of CBI as in effect on the Effective Date shall
constitute the Bylaws of the Surviving Corporation.  The directors and officers
of CBI on the Effective Date shall become the directors and officers of the
Surviving Corporation.  Any vacancy in the Board of Directors or officers may be
filled in the manner provided in the Bylaws of the Surviving Corporation.  The
directors and officers shall hold office as prescribed in the Bylaws.
<PAGE>
 
          3.2  Subsidiaries of Commercial.  The Articles of Incorporation of the
Subsidiaries and the Bylaws of the Subsidiaries, as in effect on the Effective
Date, shall continue respectively as the Articles of Incorporation and Bylaws of
the Subsidiaries until the same shall thereafter be altered, amended or repealed
in accordance with law, such Articles of Incorporation or said Bylaws.  The
directors and officers of the Subsidiaries on the Effective Date shall continue
as the directors and officers of the Subsidiaries after the Merger, except to
the extent that such Subsidiaries may be restructured or consolidated on or
after the Merger, and shall hold office as prescribed in the Bylaws of such
Subsidiaries and applicable law, until their successors shall have been elected
and shall qualify.

          3.3  Wesbanco Directors.  Wesbanco covenants and agrees that as of the
Effective Date it will appoint as directors of Wesbanco William E. Mildren, Jr.,
Robert K. Tebay, James W. Swearingen and Larry G. Johnson, or, if one or more of
them should be unwilling or unable to serve, a person or persons to be
designated by Commercial  ("Substituted Person"), and acceptable to Wesbanco.
Such individuals shall serve until the next annual meeting of shareholders, and
Wesbanco shall include such persons on the list of nominees for the position of
director presented by the Wesbanco Board of Directors and for which said Board
shall solicit proxies at its next annual meeting of shareholders, with such
persons to be nominated for such terms as are available under Wesbanco's Bylaws,
except that such Directors shall be elected to separate classes of Wesbanco's
classified Board of Directors to the extent feasible; and provided that in the
event that one or more of the Commercial nominees are nominated as set forth
above by the Wesbanco Board of Directors for less than full three year terms,
upon the expiration of any such lesser term, Wesbanco covenants and agrees that
it will again include such person or persons on the list of nominees for the
position of Wesbanco director presented by its Board of Directors for a full
three year term and shall solicit proxies for said person or persons for the
annual meeting or meetings of shareholders at which such election or elections
shall be held.

Wesbanco also covenants and agrees that as of the Effective Date it will appoint
William E. Mildren, Jr. as a member of the Executive Committee of the Board of
Directors of Wesbanco, and covenants and agrees that it will continue to appoint
or elect William E. Mildren, Jr. (or the designated Substituted Person for the
said William E. Mildren, Jr. if he should be unable to serve) for so long as he
serves as a Director of Wesbanco pursuant to the requirements of this Section
3.3.

                                   SECTION 4
                             SHAREHOLDER APPROVALS

          4.1  Commercial Shareholders' Meeting.  Subject to the receipt by
Commercial of the fairness opinion described in Section 11.3(c) hereof,
Commercial shall submit the Agreement to its shareholders in accordance with the
WVCA at a meeting duly called, properly noticed and held at the earliest
practicable date (considering the regulatory approvals required to be obtained)
after the receipt of such opinion.  In connection with such meeting, Commercial
shall send to its shareholders the Proxy Statement referred to in Section 13.1
hereof.  Subject to the fiduciary duties of the Board of Directors of Commercial
to Commercial and its shareholders, the Board of Directors of Commercial shall
recommend a vote in favor of the Merger and shall use its best efforts to obtain
at such meeting the affirmative vote of the Commercial shareholders required to
effectuate the transactions contemplated by the Agreement.

          4.2  CBI Shareholder Meeting or Consent.  CBI shall promptly submit
the Agreement to its shareholder, Wesbanco, for approval in accordance with the
WVCA.

          4.3  Wesbanco Shareholder Meeting.  Wesbanco shall submit the
Agreement to its shareholders in accordance with the WVCA at a meeting duly
called, properly noticed and held at the earliest practicable date (considering
the regulatory approvals required to be obtained).  In connection with such
meeting, Wesbanco shall send to its shareholders the Proxy Statement referred to
in Section 13.1 hereof.  Subject to the fiduciary duties of the Board of
Directors of Wesbanco to Wesbanco and its shareholders, the Board of Directors
of Wesbanco shall recommend a vote in favor of the Merger and shall use its best
efforts to obtain at such meeting the affirmative vote of the Wesbanco
shareholders required to effectuate the transactions contemplated by the
Agreement.
<PAGE>
 
                                   SECTION 5
                              CONVERSION OF SHARES
     5.1  Conversion, Ratio and Option.  The manner of converting or exchanging 
the shares of CBI and Commercial shall be as follows:
          (a) Each share of Commercial Common Stock issued and outstanding
     immediately prior to the Effective Time, except shares of Commercial Common
     Stock issued and held in treasury of Commercial or beneficially owned by
     CBI or Wesbanco, other than in a fiduciary capacity by Wesbanco for others,
     and shares as to which dissenters' rights are exercised pursuant to W.Va.
     Code Annot. Section 31-1-122, shall by virtue of the Merger and at the
     Effective Time of the Merger:
               (i) Be exchanged for and become, without action on the part of
          the holder thereof, 2.85 shares of the Common Stock of Wesbanco,
          having equal rights and privileges with respect to all other Common
          Stock of Wesbanco issued and outstanding as of the Effective Time of
          the Merger.
               (ii) No fractional shares of Wesbanco Common Stock will be issued
          in connection with the Merger.  In lieu thereof each stockholder of
          Commercial otherwise entitled to a fractional share of Wesbanco will
          receive cash therefore in an amount based on a value of $28.37 per
          whole share of Wesbanco stock, at the time of the exchange, or at the
          election of such holder, shall be entitled to purchase the remaining
          fraction of such share from Wesbanco based on such price.

               (iii)  In the event of any change in Wesbanco Common Stock by
          reason of stock dividends, split-ups, mergers, recapitalizations,
          combinations, exchanges of shares or the like, the type and number of
          shares to be issued pursuant to Section 5.1(a)(i) and (ii) hereof
          shall be adjusted proportionately.
          (b) Each share of common stock of CBI issued and outstanding
     immediately prior to the Effective Time shall, at the Effective Time,
     become one issued and outstanding share of common stock of the Surviving
     Corporation.

     5.2  Shares Owned by Commercial, Wesbanco or CBI.   Each share of
Commercial  Common Stock issued and held in the treasury of Commercial or
beneficially owned by Wesbanco or CBI, other than in a fiduciary capacity, at
the Effective Time of the Merger shall be canceled and retired, and no shares of
stock or the securities of Wesbanco shall be issuable with respect thereto.

     5.3  Exchange for Stock.  On and after the Effective Date of the Merger,
each holder of Commercial Common Stock, upon presentation and surrender of a
certificate or certificates therefore to the Exchange Agent (Wesbanco Bank
Wheeling), shall be entitled to receive in exchange therefore a certificate or
certificates representing the number of shares of Wesbanco Common Stock to which
he or she is entitled as provided herein, and payment in cash for any fractional
share of common stock which he is entitled to receive, without interest, should
such shareholder not elect to purchase the remaining fraction of such share of
common stock at the price above set forth.  Until so presented and surrendered
in exchange for a certificate representing Wesbanco Common Stock, each
certificate which represented issued and outstanding shares of Commercial Common
Stock immediately prior to the Effective Time shall be deemed for all purposes
to evidence ownership of the number of shares of Wesbanco Common Stock into
which such shares of stock have been converted pursuant to the Merger.  Until
surrender of such certificates in exchange for certificates representing the
converted stock, the holder thereof shall not receive any dividend or other
distribution payable to holders of shares of such stock; provided, however, that
upon surrender of such certificates representing such converted stock in
exchange for certificates representing the stock into which it has been
converted, there shall be paid to the record holder of the certificate
representing Wesbanco Common Stock issued upon such surrender, the amount of
dividends or other distributions (without interest) which theretofore became
payable with respect to the number of shares of such stock represented by the
certificate or certificates to be issued upon such surrender, together with
payment of cash for any fractional share to which such holder is entitled, as
above set forth.

     5.4  Closing of Stock Transfer Books.  On the Effective Date, the stock
transfer books of Commercial shall be closed, and no shares of Common Stock or
Preferred Stock of Commercial outstanding the day prior to the Effective Date
shall thereafter be transferred.
<PAGE>
 
          5.5  Directors' Qualifying Shares.  Immediately upon completion of the
conversion provided for above, the continuing Directors of Commercial or its
Subsidiaries who are elected to serve on the board of directors of one or more
banking Subsidiaries of Wesbanco shall maintain at least the minimum number of
shares of common stock of Wesbanco as are required to be held as directors'
qualifying shares under applicable law for continued membership on the Board of
Directors of any of the Wesbanco Subsidiaries.

                                   SECTION 6
                               DISSENTERS RIGHTS

          6.1       Subject to the rights of Wesbanco and Commercial, as
permitted by Section 11.1(i) of the Agreement, to terminate the Agreement and
abandon the Merger in the event that the number of Objecting Shares (as
hereinafter defined) shall exceed 10% of the shares of Commercial issued and
outstanding on the date of the shareholders' meeting described in Sections 4.1
and 13.1 of this Agreement and entitled to vote on this Agreement (hereinafter,
"Voting Shares"), the rights and remedies of a dissenting shareholder under the
WVCA shall be afforded to any shareholder of Commercial who objects to the
Merger in a timely manner in accordance with the WVCA, and who takes the
necessary steps in a timely manner in accordance with the WVCA to perfect such
shareholder's rights as a dissenting shareholder (such shareholder being
hereafter referred to as a "Dissenting Shareholder").  The Surviving Corporation
will make such payments as are required to be made to Dissenting Shareholders in
the exercise of such rights.  The term "Objecting Shares" shall mean the shares
of those holders of Commercial Common Stock who shall file written objections
with respect to such shares, in a timely manner in accordance with the WVCA, to
the Agreement, shall not vote in favor of the Agreement, and have made written
demand for the fair value of such shares within ten days, in accordance with
WVCA Section 31-1-123.  The Objecting Shares held by shareholders who do not
become Dissenting Shareholders shall be converted into Wesbanco Common Stock in
accordance with Section 5 hereof.

                                   SECTION 7
            REPRESENTATIONS, WARRANTIES AND COVENANTS OF COMMERCIAL
          Commercial represents and warrants to and covenants with Wesbanco and
CBI, in its own right and with respect to its wholly owned Subsidiaries, that:

          7.1  Organization and Qualification of Commercial.  Commercial is a
corporation duly organized, validly existing and in good standing under the laws
of the State of West Virginia and has the full corporate power and authority to
own all of its properties and assets and to carry on its business as it is now
being conducted, and neither the ownership of its property nor the conduct of
its business requires it or its Subsidiaries to be qualified to do business in
any other jurisdiction, except where the failure to be so qualified, considering
all such cases in the aggregate, does not involve a material risk to the
business, properties, financial position or results of operations of Commercial
and its Subsidiaries taken as a whole.

          7.2  Authorization of Agreement.  The Board of Directors of Commercial
has authorized the execution of this Agreement as set forth herein, and subject
to the approval of this Agreement by the shareholders of Commercial as provided
in the Articles of Incorporation and Bylaws of Commercial and West Virginia Code
31-1-117, Commercial has the corporate power and is duly authorized to merge
with CBI pursuant to this Agreement, and this Agreement is a valid and binding
agreement of Commercial enforceable in accordance with its terms, except as
enforceability may be subject to applicable bankruptcy, insolvency, moratorium
or other similar laws affecting the enforcement of creditors' rights generally
and to any equitable principles limiting the right to obtain specific
performance of certain obligations thereunder.
<PAGE>
 
          7.3  No Violation of Other Instruments.  Subject to obtaining any
required consent (which consents will be obtained by Commercial prior to
Closing), the execution and delivery of this Agreement do not, and the
consummation of the Merger and the transactions contemplated hereby will not,
violate any provisions of Commercial's Articles of Incorporation or Bylaws, or
any provision of, or result in the acceleration of any obligation under, any
material mortgage, deed of trust, note, lien, lease, franchise, license, permit,
agreement, instrument, law, order, arbitration award, judgment or decree or in
the termination of any material license, franchise, lease or permit to which
Commercial or its Subsidiaries (as defined in Section 7.5) are a party or by
which they are bound.  After the approval of this Agreement by the shareholders
of the common stock of Commercial, the Board of Directors and the shareholders
of Commercial will have taken all corporate action required by applicable law,
the Articles of Incorporation of Commercial, its Bylaws or otherwise to
authorize the execution and delivery of this Agreement and to authorize the
Merger of Commercial and CBI pursuant to this Agreement.

          7.4  Financial Statements.  Commercial has delivered to Wesbanco
copies of its consolidated statements of condition as of December 31, 1996,
1995, and 1994, and the interim period ended June 30, 1997, and its consolidated
statements of income, consolidated statements of changes in shareholders' equity
and consolidated statements of changes in financial position for the three year
period ended December 31, 1996, and the interim period ended June 30, 1997,
together with the notes thereto, accompanied by an audit report relating to the
financial statements for the three years ended December 31, 1996, of Harman,
Thompson, Mallory & Ice, A.C., independent auditors.  Such statements, together
with the related notes to all of said financial statements, present fairly the
consolidated financial position of Commercial and its Subsidiaries and the
consolidated results of their operations as of the dates and for the periods
ended on the dates specified in accordance with generally accepted accounting
principles consistently applied throughout the periods indicated, except as may
be specifically disclosed in those financial statements, including the notes to
the financial statements attached thereto and subject to normal recurring year
end adjustments.

          7.5  Subsidiaries of Commercial.  The Subsidiaries of Commercial are
Commercial Banking and Trust Company, Jackson County Bank, Farmers & Merchants
Bank of Ritchie County, The Dime Bank, Union Bank of Tyler County, The Community
Bank, Bank of Paden City,  Hometown Finance Company, Hometown Insurance Agency,
Inc. and CommBanc Investments, Inc.  Such corporations are duly organized,
validly existing, and in good standing under the laws of the States of West
Virginia or Ohio, as the case may be, and have the requisite corporate power and
authority to own and lease their properties and to conduct their business as
they are now being conducted and are currently contemplated to be conducted.
Commercial owns 100% of the issued and outstanding stock of such corporations.
All issued and outstanding shares of stock of the Subsidiaries have been fully
paid, were validly issued and are nonassessable.

          7.6  No Action, Etc.  Except as disclosed in the Disclosure Schedule
of Commercial  dated not more than 60 days from the date hereof (the "Commercial
Disclosure Schedule"), and as supplemented on the Effective Date, there are no
suits, actions, proceedings, claims or investigations (formal or informal)
pending, or to the knowledge of Commercial, threatened against or relating to
Commercial, its Subsidiaries, their business or any of their properties or
against any of their officers or directors (in their capacity as such) in law or
in equity or before any governmental agency.  There are no suits, actions,
proceedings, claims or investigations against Commercial, its Subsidiaries,
properties or against any of their officers or directors (in their capacity as
such) in law or in equity or before any governmental agency which, individually
or in the aggregate, would, or is reasonably likely to, if determined adversely
to such party, materially adversely affect the financial condition (present or
prospective), businesses, properties or operations of Commercial or its
Subsidiaries or the ability of Commercial or its Subsidiaries to conduct their
business as presently conducted or to consummate the transaction contemplated
hereby, and Commercial does not know of any basis for any such action or
proceeding.  Except as disclosed in the Commercial Disclosure Schedule,
Commercial and its Subsidiaries are not parties or subject to any cease and
desist order, agreement or similar arrangement with a regulatory authority which
restricts their operations or requires any action, and neither Commercial nor
its Subsidiaries are transacting business in material violation of any
applicable law, ordinance, requirement, rule, regulation or order.
<PAGE>
 
          7.7  Capitalization.  The authorized capital stock of Commercial
consists of 5,000,000  shares of common stock, par value of $5.00 per share, of
which 1,616,187shares are duly authorized, validly issued and outstanding and
are fully paid and nonassessable as of the date hereof, and 43,328 shares of
preferred stock with a par value of $100.00 per share, of which no shares are
issued and outstanding as of the date hereof.  There are no other options,
warrants, calls or commitments of any kind entitling any person to acquire, or
securities convertible into, Commercial Common Stock, except as provided in the
Option Agreement dated the date hereof to be issued in accordance with this
Agreement, and the Shareholder Rights Plan adopted by the Board of Directors of
Commercial on August 14, 1996.

          The rights issued to shareholders of Commercial pursuant to the
Shareholder Rights Plan adopted by Commercial on August 14, 1996 (the "Rights
Plan") have been redeemed in accordance with the terms of the Rights Plan.  The
rights and the Rights Plan have been terminated in accordance with the
provisions of such plan, with no further obligations to the shareholders of
Commercial, and the rights and the Rights Plan are no longer in force or
effective.

          7.8  Copies of All Contracts, Leases, Etc.  Commercial has furnished,
or will furnish, to Wesbanco a list of all material contracts, leases and other
agreements to which Commercial is a party or by which it is bound and of all
employment, pension, retirement, stock option, profit sharing, deferred
compensation, consultant, bonus, group insurance or similar plan with respect to
any of the directors, officers or other employees of Commercial and its
Subsidiaries which list will be included in the Commercial Disclosure Schedule,
and which will be updated on the Effective Date.  Commercial will provide to
Wesbanco true and complete copies of such documents as may be reasonably
requested by Wesbanco.

          7.9  Materially Adverse Contracts.  Neither Commercial nor its
Subsidiaries are a party to or otherwise bound by any contract, agreement, plan,
lease, license, commitment or undertaking which is materially adverse,
materially onerous or materially harmful to Commercial  and its Subsidiaries
taken as a whole.  There is no breach or default by any party of or with respect
to any material provision of any material contract to which Commercial or its
Subsidiaries are a party that would have a material adverse effect upon the
financial condition, operations, results of operations, business or prospects of
Commercial and its Subsidiaries taken as a whole.

          7.10  Undisclosed Liabilities.  Commercial and its Subsidiaries have
no material liabilities other than those liabilities disclosed on or provided
for in the financial statements delivered pursuant to Section 7.4 hereof, or as
may be disclosed in the Commercial Disclosure Schedule, none of which would have
a material adverse effect upon the financial condition of Commercial and its
Subsidiaries taken as a whole.

          7.11  Title to Properties.  Except for capitalized leases, liens and
encumbrances not material to the property and liens and encumbrances on property
acquired by Commercial and its Subsidiaries in foreclosure of loans and existing
at the time of foreclosure, Commercial and its Subsidiaries have good and
marketable title to all of the property, interest in properties and other
assets, real and personal, set forth in their consolidated balance sheet as of
December 31, 1996, and applicable interim period balance sheets or acquired
since the date thereof, other than property disposed of since such dates,
subject to no material liens, mortgages, pledges, encumbrances or charges of any
kind except liens reflected on said balance sheets  or set forth in the
financial statements delivered pursuant to Section 7.4 hereof, and all of their
material leases are in full force and effect and neither Commercial nor its
Subsidiaries are in material default thereunder.  No asset included in the
financial statements referred to above has been valued in such statements in
excess of its cost less depreciation or, in the case of investment securities,
in excess of cost, adjusted for amortization of premiums or accretion of
discounts.  All material real and tangible personal property owned by Commercial
or its Subsidiaries and used or leased by Commercial or its Subsidiaries in
their business is in good condition, normal wear and tear excepted, and is in
good operating order.  All of such property is insured against loss for at least
80% of the full replacement value thereof (less applicable deductibles) by
reputable insurance companies authorized to transact business in the States of
West Virginia or Ohio.
<PAGE>
 
          7.12  Proxy Statement.  The Proxy Statement referred to in Section 13
or any amendment or supplement thereto mailed to the holders of the common stock
of Commercial and Wesbanco will not contain any untrue statement of a material
fact concerning Commercial or omit to state a material fact concerning
Commercial required to be stated therein or necessary to make the statements
contained therein, in light of the circumstances under which they were made, not
misleading with respect to Commercial, and will comply, as to form in all
material respects, with the requirements of federal and West Virginia securities
laws and any other applicable Blue Sky Laws.

          7.13  ERISA.  Except as disclosed in the Commercial Disclosure
Schedule, (i) each employee benefit plan subject to Titles I and/or IV of ERISA
and established or maintained for persons including employees or former
employees of Commercial, or its Subsidiaries, (hereinafter referred to as
"Plan") has been maintained, operated, administered and funded in accordance
with its terms and with all material provisions of ERISA and the Internal
Revenue Code ("IRC") applicable thereto; (ii) no event reportable under Section
4043 of ERISA has occurred and is continuing with respect to any Plan; (iii) no
liability to PBGC has been incurred with respect to any Plan, other than for
premiums due and payable, and all premiums required to have been paid to PBGC as
of the date hereof have and as of the Effective Date will have been paid; (iv)
no Plan has been terminated, no proceedings have been instituted to terminate
any Plan, and no decision has been made to terminate or institute proceedings to
terminate any Plan; (v) no Plan is a multi-employer Plan; (vi) there has been no
cessation of, and no decision has been made to cease, operations at a facility
or facilities where such cessation could reasonably be expected to result in a
separation from employment of more than 20% of the total number of employees who
are participants under any plan; (vii) each Plan which is an employee pension
plan meets the requirements of "qualified plans" under Section 401(a) of the
IRC; (viii) no accumulated funding deficiency within the meaning of Section 412
of the IRC or Section 302 of ERISA has been incurred with respect to any Plan
subject to the funding standards of those provisions; (ix) with respect to each
Plan, there have been no prohibited transactions as defined in Section 406 of
ERISA or Section 4975 of the IRC, and there are no actions, suits or claims with
respect to the assets thereof (other than routine claims for benefits) pending
or threatened; and (x) all required reports, descriptions and notices
(including, but not limited to, Form 5500 Annual Reports, Summary Annual Reports
and Summary Plan Descriptions) have been appropriately filed or distributed with
respect to each Plan.

          7.14  Exchange Act Reports.  Commercial has delivered to Wesbanco true
and correct copies of its Form 10-K (Annual Report) for the year ended December
31, 1996, its Form 10-Q (Quarterly Report) for the quarters ended March 31,
1997, and June 30, 1997, as filed with the SEC, all of which were prepared and
filed in accordance with the applicable requirements and regulations of the SEC,
and all other documents and reports filed by Commercial with the Securities &
Exchange Commission ("SEC") pursuant to the Securities Exchange Act of 1934 (the
"Act") since January 1, 1997 (the "Reports").  Commercial has filed and will
continue to file all reports and other documents required to be filed with the
SEC pursuant to the Act in a timely manner.  All of the Reports complied in all
material respects with the Act and did not contain, as of their respective
dates, any untrue statement of a material fact or omit to state any material
fact necessary to make the statements therein not misleading in light of the
circumstances under which they were made.

          7.15  Labor Disputes. Neither Commercial nor its Subsidiaries are
directly or indirectly involved in or threatened with any labor dispute,
including, without limitation, matters regarding discrimination by reason of
race, creed, sex, handicap or national origin, which would materially and
adversely affect their financial condition, assets, businesses or operations
taken as a whole.  No collective bargaining representatives represent any
employees of Commercial or the employees of its Subsidiaries, and no petition
for election of any collective bargaining representative has been filed and to
the knowledge of Commercial and its Subsidiaries no organizational campaign on
behalf of any collective bargaining unit has been undertaken by or on behalf of
the employees of Commercial  or its Subsidiaries.

          7.16  Reserve for Possible Loan Losses.  The reserve for possible loan
losses shown on the consolidated balance sheets of Commercial and its
Subsidiaries as of December 31, 1996, and June 30, 1997, delivered pursuant to
this Agreement is adequate in all material respects as of the respective dates
thereof.
<PAGE>
 
          7.17  Taxes.  Except as may be disclosed in the Commercial Disclosure
Schedule:
               (a) Commercial and its Subsidiaries have timely and properly
     filed all Federal Income Tax Returns and all other federal, state,
     municipal and other tax returns which they are required to file, either on
     their own behalf or on behalf of their employees or other persons or
     entities, all such returns and reports being true and correct and complete
     in all material respects, and have paid all taxes, including penalties and
     interest, if any, which have become due pursuant to such returns or reports
     or forms or pursuant to assessments received by them;
               (b) Neither the Internal Revenue Service nor any other taxing
     authority is now asserting against Commercial or its Subsidiaries, or, to
     its knowledge, threatening to assert against them, or any of them, any
     material deficiency or claim for additional taxes, interest or penalty;
               (c) There is no pending or, to its knowledge, threatened
     examination of the Federal Income Tax Returns of Commercial or its
     Subsidiaries, and, except for tax years still subject to the assessment and
     collection of additional Federal income taxes under the three year period
     of limitations prescribed in IRC Section 6501(a), no tax year of Commercial
     or its Subsidiaries remains open to the assessment and collection of
     additional material Federal Income Taxes; and
               (d) There is no pending or, to its knowledge, threatened
     examination of the West Virginia Business Franchise or Ohio Franchise Tax
     Returns of Commercial or its Subsidiaries, and, except for tax years still
     subject to the assessment and collection of additional Business Franchise
     Taxes under the three year period of limitations prescribed in W.Va. Code
     Annot. Section 11-10-15, and corresponding provision of the Ohio Revised
     Code, no tax year of Commercial or its Subsidiaries remains open to the
     assessment and collection of additional Business Franchise Taxes.
               (e) Commercial, and its Subsidiaries, have properly accrued and
     reflected on their December 31, 1996, consolidated balance sheet, delivered
     pursuant to Section 7.4 hereof, and have thereafter to the date hereof
     properly accrued, and will from the date hereof through the Closing Date
     properly accrue, all liabilities for taxes and assessments, and will timely
     and properly file all such federal, state, local and foreign tax returns
     and reports and forms which they are required to file, either on their own
     behalf or on behalf of their employees or other persons or entities, all
     such returns and reports and forms to be true and correct and complete in
     all respects, and will pay or cause to be paid when due all taxes,
     including penalties and interest, if any, which have become due pursuant to
     such returns or reports or forms or pursuant to assessments received by
     them, all such accruals being in the aggregate sufficient for payment of
     all such taxes and assessments.

          7.18  Absence of Certain Changes.  Except as may be disclosed in the
Commercial  Disclosure Schedule, or except in connection with the transactions
contemplated by this Agreement, since December 31, 1996:
               (a) There has been no change in the material assets, financial
     condition or liabilities (contingent or otherwise), business, or results of
     operations of Commercial and its Subsidiaries which has had, or changes
     which in the aggregate have had, a material adverse effect on the assets,
     financial condition or results of operations of Commercial and its
     Subsidiaries taken as a whole, nor to their knowledge, has any event or
     condition occurred which may result in such change or changes;
               (b) There has not been any material damage, destruction or loss
     by reason of fire, flood, accident or other casualty (whether insured or
     not insured) materially and adversely affecting the assets, financial
     condition, business or operations of Commercial or its Subsidiaries taken
     as a whole;
               (c) Other than in the ordinary course of business, neither
     Commercial nor its Subsidiaries have disposed of, or agreed to dispose of,
     any of their material properties or assets, nor have they leased to others,
     or agreed to so lease, any of such material properties or assets;
               (d) There has not been any change in the authorized, issued or
     outstanding capital stock of Commercial except as provided for in this
     Agreement, or any material change in the outstanding debt of Commercial or
     its Subsidiaries, other than changes due to payments in accordance with the
     terms of such debt or changes in deposits, Federal funds purchased,
     repurchase agreements or other short- term borrowings in the ordinary
     course of business;
<PAGE>
 
               (e) Except as otherwise disclosed in this Agreement, Commercial
     has not granted any warrant, option or right to acquire, or agreed to
     repurchase, redeem or otherwise acquire, any shares of its capital stock or
     any other of its securities whatsoever;
               (f) Commercial and its Subsidiaries have, and shall have at
     Closing, personnel sufficient to adequately staff all key positions within
     their respective operations.  There has not been any material increase in
     the compensation or fees payable by Commercial or its Subsidiaries to their
     respective directors or officers for services in their capacities as such,
     other than increases in the regular course of business in accordance with
     past practices or the personnel policies of Commercial or its Subsidiaries,
     respectively, nor any material increase in expenditures for any bonus,
     insurance, pension or other employee benefit plan, payment or arrangement
     for or with any of such directors or officers other than increases in the
     regular course of business in accordance with past practices or the
     personnel policies of Commercial or its Subsidiaries;
               (g) Neither Commercial nor its Subsidiaries have made any
     material loan or advance other than in the ordinary course of business;
               (h) Neither Commercial nor its Subsidiaries have made any
     expenditure or major commitment for the purchase, acquisition, construction
     or improvement of any material asset or assets which in the aggregate would
     be material other than in the ordinary course of business;
               (i) Neither Commercial nor its Subsidiaries have entered into any
     other material transaction, contract or lease or incurred any other
     material obligation or liability other than in the ordinary course of
     business; and
               (j) There has not been any other event, condition or development
     of any kind which materially and adversely affects the material assets,
     financial condition or results of operations of Commercial or its
     Subsidiaries, taken as a whole, and neither Commercial nor its Subsidiaries
     have knowledge of any such event, condition or development which may
     materially and adversely affect the assets, financial condition or results
     of operations of Commercial and its Subsidiaries, taken as a whole.

          7.19  Fidelity Bonds.  The Subsidiaries have continuously maintained
fidelity bonds insuring them against acts of dishonesty by each of their
officers and employees in such amounts as are required by law and as are
customary, usual and prudent for banks of their size.  Since January 1, 1997,
there have been no claims under such bonds and, except as disclosed in the
Commercial Disclosure Schedule, neither Commercial nor its Subsidiaries are
aware of any facts which would form the basis of a claim under such bonds.
Neither Commercial nor its Subsidiaries have any reason to believe that their
fidelity coverage will not be renewed by the applicable carrier on substantially
the same terms as its existing coverage.

          7.20  Negative Covenants.  Except as otherwise contemplated hereby,
between the date hereof and the Effective Date, or the time when this Agreement
terminates as provided herein, Commercial will not, except as contemplated by
this Agreement, without the prior written approval of Wesbanco:
               (a) Make any change in its authorized capital stock;
               (b) Except for a minimum of 116,000 shares and a maximum of
     142,000 shares issuable in Commercial's acquisition of Gateway Bancshares,
     Inc., issue any shares of its common stock, securities convertible into its
     common stock, or any long term debt securities;
               (c) Issue or grant any options, warrants or other rights to
     purchase shares of its common stock;
               (d) Declare or pay any dividends or other distributions on any
     shares of common stock other than cash dividends which do not in the
     aggregate exceed the lesser of $1.20 cents per share per year (to be paid
     on a quarterly basis in such proportions as are consistent with past
     practices) or 50% of the after- tax income of Commercial for the tax years
     in which paid;
               (e) Purchase or otherwise acquire, or agree to acquire, for a
     consideration any share of its capital stock (other than in a fiduciary
     capacity);
<PAGE>
 
               (f) Except as otherwise contemplated by this Agreement or as
     disclosed in or permitted by or under the conditions set forth in Section
     7.18(f) above and except for any amendments required by law, enter into or
     amend any employment, pension, retirement, stock option, profit sharing,
     deferred compensation, consultant, bonus, group insurance or similar plan
     in respect of any of its directors, officers or other employees for
     services in their capacities as such or materially increase its
     contribution to any pension plan, except as disclosed in the Commercial
     Disclosure Schedule, regarding pension or retirement plans or increases in
     accordance with past practices;
          (g) Take any action materially and adversely affecting the financial
     condition (present or prospective), businesses, properties or operations of
     Commercial or its Subsidiaries, taken as a whole;
          (h) Acquire or merge with any other company or acquire any branch or,
     other than in the ordinary course of business, any assets of any other
     company;
               (i) Except in the ordinary course of business as heretofore
     conducted, and except as hereinabove provided, mortgage, pledge or subject
     to a lien or any other encumbrance any of its material assets, dispose  of
     any of its material assets, incur or cancel any material debts or claims,
     or increase any compensation or benefits payable to its officers or
     employees (other than as permitted in Sections 7.18(f) and 7.20(f) hereof),
     except in the ordinary course of business as heretofore conducted, or take
     any other action not in the ordinary course of its business as heretofore
     conducted or incur any material obligation or enter into any material
     contract; or
               (j) Amend its Articles of Incorporation or Bylaws, except as may
     be necessary to carry out this Agreement or as required by law.

     7.21.  Additional Covenants.  Except as otherwise contemplated by this 
Agreement, Commercial covenants and agrees:
               (a) That it will promptly advise Wesbanco in writing of the name
     and address of, and the number of shares of Commercial stock held by, each
     stockholder who elects to exercise his or her right to dissent to the
     Merger pursuant to West Virginia Code Annot. Sections 31-1-122 and 123;
               (b) Subsequent to the date of this Agreement and prior to the
     Effective Date, that it will operate its business only in the ordinary
     course and in a manner consistent with past practice;
               (c) To the extent consistent with the fiduciary  duties of the
     Board of Directors to Commercial and its shareholders and in compliance
     with applicable law, that it will use its best efforts to take or cause to
     be taken all action required under this Agreement on its part to be taken
     as promptly as practicable so as to permit the consummation of the Merger
     at the earliest possible date and to cooperate fully with the other parties
     to that end;
               (d) Commercial will not, and will not permit any person acting on
     behalf of Commercial or its Subsidiaries to, directly or indirectly,
     initiate or solicit any acquisition proposal by any person, corporation or
     entity.  For the purposes of this subsection, "acquisition proposal" means
     any proposal to merge or consolidate with, or acquire all or any
     substantial portion of the assets of, Commercial or its Subsidiaries, or
     any tender or exchange offer (or proposal to make any tender or exchange
     offer) for any shares of stock of Commercial, or any proposal to acquire
     more than 10% of the outstanding shares of stock of Commercial or any
     options, warrants or rights to acquire, or securities convertible into or
     exchangeable for, more than 10% of the outstanding shares of stock of
     Commercial.  Commercial will give Wesbanco notice by telephone, promptly
     after receipt thereof, of all material facts relating to any acquisition
     proposal or any inquiry with respect to any acquisition proposal and shall
     confirm such notice in writing immediately thereafter;
               (e) To deliver to Wesbanco all Forms filed with the SEC for
     periods ending after the date of this Agreement within seven (7) days after
     the filing of each such report with the SEC;
               (f) To promptly advise Wesbanco of any material adverse change in
     the financial condition, assets, businesses or operations of Commercial or
     its Subsidiaries, taken as a whole, or any material changes or inaccuracies
     in data provided to Wesbanco pursuant to this Agreement;
               (g) To maintain in full force and effect its and its
     Subsidiaries' present fire, casualty, public liability, employee fidelity
     and other insurance coverages or replacement insurance coverage at
     substantially the same premium and insurance levels;
<PAGE>
 
               (h) To cooperate with Wesbanco in furnishing such information
     concerning the business and affairs of Commercial, its Subsidiaries and
     their respective directors and officers as is reasonably necessary or
     requested in order to prepare and file any application for regulatory or
     governmental approvals, including, but not limited to, an application to
     the Federal Reserve Board and the West Virginia Department of Banking for
     prior approval of the acquisition of Commercial by Wesbanco as contemplated
     hereunder.  Consistent with its fiduciary duties, Commercial will use its
     best efforts to obtain the approval or consent of any federal, state or
     other regulatory agency having jurisdiction and of any other party to the
     extent that such approvals or consents are required to effect the Merger
     and the transactions contemplated hereby or are required with respect to
     the documents described in Section 7.3 hereof; and
               (i) To cooperate with Wesbanco in furnishing such information
     concerning the business of Commercial and its Subsidiaries as is reasonably
     necessary or requested in order to prepare and file any Registration
     Statement to be prepared in connection with the issuance of Wesbanco Common
     Stock as provided in Section 13 hereof.

                                   SECTION 8
         REPRESENTATIONS, WARRANTIES AND COVENANTS OF WESBANCO AND CBI
     Wesbanco and CBI represent and warrant to Commercial and covenant with 
Commercial  that:

          8.1  Corporate Organization of Wesbanco and Subsidiaries.  Wesbanco
is, and upon execution hereof CBI will be, a corporation duly organized, validly
existing and in good standing under the laws of the State of West Virginia, with
full corporate power and authority to carry on its business as it is now being
conducted and as contemplated by the Agreement and to own the properties and
assets which it owns, and neither the ownership of its property nor the conduct
of its business requires it, or any of its subsidiaries, to be qualified to do
business in any other jurisdiction except where the failure to be so qualified,
considering all such cases in the aggregate, does not involve a material risk to
the business, properties, financial position or results of operations of
Wesbanco and its subsidiaries taken as a whole.  Each of Wesbanco's subsidiaries
("Wesbanco Subs"), other than CBI, is a West Virginia, Ohio or Delaware
corporation, duly organized and validly existing in good standing under the laws
of Ohio, West Virginia or Delaware, as the case may be, with full corporate
power and authority to carry on its business as it is now being conducted and to
own the properties and assets which it owns.  All issued and outstanding shares
of stock of CBI and Wesbanco Subs are held, beneficially and of record, by
Wesbanco and have been or, as to CBI, on the date of its execution hereof, will
have been, fully paid, were validly issued and are nonassessable.  There are no
options, warrants to purchase or contracts to issue, or contracts or any other
rights entitling anyone to acquire, any other stock of CBI or any of the
Wesbanco Subs or securities convertible into shares of stock of CBI or any of
the Wesbanco Subs.

          8.2   Corporate Power and Action.  The Board of Directors of
Wesbanco has authorized the execution of this Agreement as set forth herein, and
subject to the approval of this Agreement by the shareholders of Wesbanco as
provided in its Articles of Incorporation, its Bylaws and the WVCA, Wesbanco has
the corporate power and is duly authorized to merge with Commercial, pursuant to
this Agreement, and this Agreement is a valid and binding agreement of Wesbanco
enforceable in accordance with its terms, except as enforceability may be
subject to applicable bankruptcy, insolvency, moratorium or other similar laws
affecting the enforcement of creditors' rights generally and to any equitable
principles limiting the right to obtain specific performance of certain
obligations thereunder.  Upon execution hereof by CBI and subject to the
approval hereof by Wesbanco as its sole shareholder, CBI has the corporate power
to execute and deliver this Agreement and has taken all action required by law,
its Articles of Incorporation, its Bylaws or otherwise to authorize and approve
such execution and delivery, the performance of the Agreement, the Merger and
the consummation of the transactions contemplated hereby; and this Agreement is
a valid and binding agreement of CBI enforceable in accordance with its terms,
except as enforceability may be subject to applicable bankruptcy, insolvency,
moratorium or other similar laws affecting the enforcement of creditors' rights
generally and to any equitable principles limiting the right to obtain specific
performance of certain obligations thereunder.
<PAGE>
 
          8.3  Transfer of Securities to Exchange Agent Prior to, or as of the
Closing Date.  Prior to, or at the Closing Date, Wesbanco will deliver to the
Exchange Agent, Wesbanco Bank Wheeling, for the benefit of the holders of the
common stock of Commercial, an amount of common stock of Wesbanco and cash
sufficient to meet the necessary amount of securities and cash required pursuant
to Section 5.

          8.4  No Violation of Other Instruments.  Subject to obtaining any
required consents (which consents will be obtained by Wesbanco prior to the
Closing), the execution and delivery of this Agreement do not, and the
consummation of the Merger and the transactions contemplated hereby will not,
violate any provision of the Articles of Incorporation or Bylaws of Wesbanco or
any of the Wesbanco Subs or any provision of, or result in the acceleration of
any obligation under, any material mortgage, Deed of Trust, note, lien, lease,
franchise, license, permit, agreement, instrument, law, order, arbitration
award, judgment or decree, or in the termination of any material license,
franchise, lease or permit, to which Wesbanco or any of the Wesbanco Subs, is a
party or by which they are bound.

          8.5  Application for CBI.  Wesbanco shall cause to be filed with the
West Virginia Secretary of State an application to organize and incorporate CBI
as a West Virginia corporation, in accordance with the provisions of the West
Virginia Code, and upon the approval of such application and the issuance of a
Certificate of Incorporation for CBI by the Secretary of State of West Virginia,
Wesbanco shall cause CBI to execute and enter into this Agreement and cause CBI
to take such action as is provided in this Agreement on CBI's part to be taken.

          8.6  Good Faith.  Wesbanco shall use its best efforts in  good faith
to take or cause to be taken all action required under this Agreement on its
part to be taken as promptly as practicable so as to permit the consummation of
this Agreement at the earliest possible date and cooperate fully with the other
parties to that end.

          8.7  Exchange Act Reports.  Wesbanco has delivered to Commercial true
and correct copies of its Form 10-K (Annual Report) for the year ended December
31, 1996, and its Forms 10-Q (Quarterly Report) for the quarters ended March 31,
1997, and June 30, 1997, as filed with the SEC, all of which were prepared and
filed in accordance with the applicable requirements and regulations of the SEC.
Wesbanco has also delivered to Commercial true and correct copies of all
documents and reports filed by Wesbanco with the SEC pursuant to the Exchange
Act since January 1, 1997 (the "Wesbanco Reports").  Wesbanco has filed and will
continue to file all reports and other documents required to be filed with the
SEC pursuant to the Exchange Act in a timely manner.  All of the Wesbanco
Reports complied in all material respects with the Act and did not contain, as
of their respective dates, any untrue statement of a material fact or omit to
state any material fact necessary to make the statements therein not misleading
in light of the circumstances under which they were made.

          8.8  Subsidiaries of Wesbanco.  In addition to CBI, the subsidiaries
of Wesbanco are Wesbanco Bank Wheeling, a West Virginia banking corporation,
Wesbanco Bank Charleston, a West Virginia banking corporation, Wesbanco Bank
Parkersburg, a West Virginia banking corporation, Wesbanco Bank Fairmont, Inc.,
a West Virginia banking corporation, Wesbanco Bank Barnesville, an Ohio banking
corporation, FFB Corporation, a West Virginia corporation, Vandalia National
Corporation, a Delaware corporation, Wesbanco Properties, Inc., a West Virginia
corporation and Wesbanco Mortgage Company, a West Virginia corporation.  All
have the requisite corporate power and authority to own and lease their
respective properties and to conduct their respective businesses as they are now
being conducted and are currently contemplated to be conducted.  Wesbanco owns
100% of the issued and outstanding stock of all such corporations.

          8.9  Registered Bank Holding Company.  Wesbanco is a duly registered
bank holding company under the Bank Holding Company Act of 1956, as amended.

          8.10  Authority to Issue Shares.  The shares of common stock of
Wesbanco to be issued pursuant to this Agreement will be duly authorized at the
time the Merger is consummated.  When issued upon the terms and conditions
specified in this Agreement, such shares shall be validly issued, fully paid,
and nonassessable.  The shareholders of Wesbanco have, and will have, no
preemptive rights with respect to the issuance of the shares of Wesbanco Common
Stock to be authorized and issued in the transaction contemplated in this
Agreement.
<PAGE>
 
          8.11  Financial Statements.  Wesbanco has delivered to Commercial
copies of its consolidated balance sheets as of December 31, 1996, 1995, and
1994 and the interim period ended June 30, 1997, and its consolidated statements
of income, consolidated statements of changes in shareholders' equity and
consolidated statements of changes in financial position for the three year
period ended December 31, 1996, and the interim period ended June 30, 1997,
together with the notes thereto, accompanied by an audit report of Ernst &
Young, LLP, independent auditors.  Such statements and the related notes to all
of said financial statements, present fairly the consolidated financial position
of Wesbanco and its consolidated subsidiaries and the consolidated results of
their operations as of the dates and for the periods ended on the dates
specified in accordance with generally accepted accounting principles
consistently applied throughout the periods indicated, except as may be
specifically disclosed in those financial statements, including the notes to the
financial statements attached thereto, and subject to normal recurring year end
adjustments.

          8.12  No Action, Etc..  Except as disclosed in the Wesbanco Disclosure
Schedule, dated not more than 60 days from the date hereof (the "Wesbanco
Disclosure Schedule"), and as supplemented on the Effective Date, there are no
suits, actions, proceedings, claims or investigations (formal or informal)
pending, or to the knowledge of Wesbanco pending or threatened, against or
relating to Wesbanco, its subsidiaries, its businesses or any of its properties
or against any of their officers or directors (in their capacity as such) in law
or in equity or before any governmental agency.  There are no suits, actions,
proceedings, claims or investigations against or relating to Wesbanco, its
subsidiaries, its businesses, its properties or against any of their officers or
directors (in their capacity as such) in law or in equity or before any
governmental agency, which, individually or in the aggregate, would, or is
reasonably likely to, if determined adversely to such party, materially
adversely affect the financial condition (present or prospective), businesses,
properties or operations of Wesbanco or its subsidiaries or the ability of
Wesbanco or its subsidiaries to conduct its business as presently conducted or
consummate the transaction contemplated hereby, and Wesbanco does not know of
any basis for any such action or proceeding.  Neither Wesbanco nor any of its
subsidiaries are a party or subject to any cease and desist order, agreement or
similar arrangement with a regulatory authority which restricts its operations
or requires any action and neither Wesbanco nor any of its subsidiaries are
transacting business in material violation of any applicable law, ordinance,
requirement, rule, order or regulation.

          8.13  Capitalization.  The authorized capital stock of Wesbanco
consists of 25,000,000   shares of common stock, par value of $2.0833 per share,
of which 16,050,795 shares are duly authorized, validly issued and outstanding
(as of June 30, 1997) and are fully paid and nonassessable, and 1,000,000 shares
of preferred stock, without par value, none of which are issued or outstanding.
There are no options, warrants, calls or commitments of any kind entitling any
person to acquire, or securities convertible into, Wesbanco Common Stock, except
as herein provided.  At June 30, 1997, Wesbanco held 21,542 shares of its common
stock as treasury stock.  Wesbanco has no other reserve commitments with respect
to its common stock.  The current Wesbanco dividend is $0.20 per calendar
quarter and subject to regulatory, statutory and fiduciary requirements, it has
no present plan or intention to change such dividend.

          Upon execution hereof by CBI, the authorized capital stock of CBI will
consist of 500 shares of common stock, par value of $10.00 per share, of which
all such shares will be duly authorized and validly issued and outstanding and
will be fully paid and nonassessable.  There are no options, warrants, calls or
commitments of any kind relating to, or securities convertible into CBI Common
Stock.

          8.14  Copies of All Contracts, Leases, Etc. Wesbanco has furnished, or
will furnish, to Commercial a list of all material contracts, leases and other
agreements to which Wesbanco is a party or by which it is bound and of all
employment, pension, retirement, stock option, profit sharing, deferred
compensation, consultant, bonus, group insurance and similar plans with respect
to any of the directors, officers or other employees of Wesbanco which list will
be included in the Wesbanco Disclosure Schedule, and which will be updated on
the Effective Date.  Wesbanco will provide to Commercial true and complete
copies of such documents as may be reasonably requested by Commercial.
<PAGE>
 
     8.15  Materially Adverse Contracts.  Neither Wesbanco nor any of its
subsidiaries are a party to or otherwise bound by any contract, agreement, plan,
lease, license, commitment or undertaking, which is materially adverse,
materially onerous, or materially harmful to Wesbanco or its subsidiaries taken
as a whole.  There is no breach or default by any party of or with respect to
any material provision of any material contract to which Wesbanco or its
subsidiaries is a party that would have a material adverse effect upon the
financial condition, operations, results of operations, business or prospects of
Wesbanco or its subsidiaries taken as a whole.

     8.16  Undisclosed Liabilities.  Wesbanco and the Wesbanco Subs have no
material liabilities other than those liabilities disclosed on or provided for
in the financial statements delivered pursuant to Section 8.11 of this
Agreement, or as may be disclosed in the Wesbanco Disclosure Schedule, none of
which would have a material adverse effect upon the financial condition of
Wesbanco and the Wesbanco Subs, taken as a whole.

     8.17  Title to Properties.  Except for capitalized leases and liens and
encumbrances not material to the property and liens and encumbrances on property
acquired by the Wesbanco Subs in foreclosure of loans and existing at the time
of foreclosure, Wesbanco and its subsidiaries have good and marketable title to
all of the property, interest in properties and other assets, real or personal,
set forth in its consolidated balance sheet as of December 31, 1996, and
applicable interim periods, or acquired since that date, subject to no material
liens, mortgages, pledges, encumbrances, or charges of any kind except liens
reflected on said balance sheets, and all of its leases are in full force and
effect and neither Wesbanco nor any of its subsidiaries is in material default
thereunder.

     No asset included in the financial statements referred to above has been
valued in such statements in excess of cost less depreciation or, in the case of
investment securities, in excess of cost, adjusted for amortization of premiums
or accretion of discounts.  All real and tangible personal property owned by
Wesbanco or its subsidiaries and used or leased by Wesbanco or its subsidiaries,
or for its business is in good condition, normal wear and tear excepted, and is
in good operating order.  All of such property is insured against loss for at
least 80% of the full replacement value thereof (less applicable deductibles) by
reputable insurance companies authorized to transact business in the State of
West Virginia.

     8.18  Proxy Statement.  The Proxy Statement referred to in Section 13.2 of
this Agreement or any amendment or supplement thereto mailed to the holders of
the common stock of Commercial and Wesbanco will not contain any untrue
statement of a material fact or omit to state a material fact required to be
stated therein or necessary to make the statements contained therein, in light
of the circumstances under which they were made, not misleading with respect to
Wesbanco, and will comply as to form in all material respects with the
requirements of federal and West Virginia securities laws and any other
applicable Blue Sky laws.

     8.19  Taxes.  Except as may be disclosed in the Wesbanco Disclosure
Schedule:
        (a) Wesbanco and its subsidiaries have timely and properly filed all
     Federal Income Tax Returns and all other federal, state, municipal and
     other tax returns which they are required to file, either on their own
     behalf or on behalf of their employees or other persons or entities, all
     such returns and reports being true and correct and complete in all
     material respects, and have paid all taxes, including penalties and
     interest, if any, which have become due pursuant to such returns or reports
     or forms or pursuant to  assessments received by them;

        (b) Neither the Internal Revenue Service nor any other taxing authority
     is now asserting against Wesbanco or any of its subsidiaries, or, to its
     knowledge, threatening to assert against them, or any of them, any material
     deficiency or claim for additional taxes, interest or penalty;
        
        (c) There is no pending or, to its knowledge, threatened examination of
     the Federal Income Tax Returns of Wesbanco or any of its subsidiaries, and,
     except for tax years still subject to the assessment and collection of
     additional federal income taxes under the three-year period of limitations
     prescribed in IRC Section 6501(a), no tax year of Wesbanco or any of its
     subsidiaries remains open to the assessment and collection of additional
     material Federal Income Taxes; and
<PAGE>
 
        (d) There is no pending or, to its knowledge, threatened examination of
     the West Virginia Business Franchise or Ohio Franchise Tax Returns of
     Wesbanco or any of its subsidiaries, and, except for tax years still
     subject to the assessment and collection of additional Business Franchise
     Taxes under the three-year period of limitations prescribed in W.Va. Code
     Annot. Section 11-10-15, and corresponding provision of the Ohio Revised
     Code, no tax year of Wesbanco or any of its subsidiaries remains open to
     the assessment and collection of additional Business Franchise Taxes.

        (e) Wesbanco, and its subsidiaries, have properly accrued and reflected
     on their December 31, 1996, consolidated balance sheet, delivered pursuant
     to Section 8.11 hereof, and have thereafter to the date hereof properly
     accrued, and will, from the date hereof, through the Closing Date, properly
     accrue all liabilities for taxes and assessments, and will timely and
     properly file all such federal, state, local and foreign tax returns and
     reports and forms which they are required to file, either on their own
     behalf or on behalf of their employees or other persons or entities, all
     such returns and reports and forms to be true and correct and complete in
     all respects, and will pay or cause to be paid when due all taxes,
     including penalties and interest, if any, which have become due pursuant to
     such returns or reports or forms or pursuant to assessments received by
     them, all such accruals being in the aggregate sufficient for payment of
     all such taxes and assessments.

     8.20  Absence of Certain Changes.  Except as may be disclosed in the
Wesbanco Disclosure Schedule, or except in connection with the transactions
contemplated by this Agreement, since December 31, 1996:

        (a) There has been no change in the material assets, financial
     condition, liabilities (contingent or otherwise), business or results of
     operation of Wesbanco and its subsidiaries which has had, or changes in the
     aggregate which have had, a material adverse effect on the assets,
     financial condition or results of operations of Wesbanco, nor, to its
     knowledge, has any event or condition occurred which may result in such
     change or changes;

        (b) There has not been any material damage, destruction, or loss by
     reason of fire, flood, accident or other casualty (whether insured or not
     insured) materially and adversely affecting the assets, financial
     condition, business or operations of Wesbanco or any of its subsidiaries
     taken as a whole;

        (c) Other than in the ordinary course of business, neither Wesbanco nor
     any of its subsidiaries have disposed of, or agreed to dispose of, any of
     their material properties or assets, nor have they leased to others, or
     agreed to so lease, any of such material properties or assets;

        (d) There has not been any change in the authorized, issued or
     outstanding capital stock of Wesbanco, except as provided for in this
     Agreement, or any material change in the outstanding debt of Wesbanco or
     any of its subsidiaries, other than changes due to payments in accordance
     with the terms of such debt or changes in deposits, federal funds
     purchased, repurchase agreements or other short-term borrowings in the
     ordinary course of business;

        (e) Except as otherwise disclosed in this Agreement, Wesbanco has not
     granted any warrant, option or right to acquire, or agreed to repurchase,
     redeem or otherwise acquire, any shares of its capital stock or any other
     of its securities whatsoever;

        (f) Neither Wesbanco nor any of its subsidiaries have made any material
     loan or advance other than in the ordinary course of business;

        (g) Neither Wesbanco nor any of its subsidiaries has entered into any
     other material transaction, contract or lease or incurred any other
     material obligation or liabilities other than in the ordinary course of
     business;

        (h) Neither Wesbanco nor any of its subsidiaries have made any
     expenditure or major commitment for the purchase, acquisition, construction
     or improvement of any material asset or assets which in the aggregate would
     be material other than in the ordinary course of business;

        (i) There have not been any dividends or other distributions declared or
     paid on any shares of Wesbanco Common Stock or preferred stock of Wesbanco
     which, taken in the aggregate with all other such distributions declared or
     paid in the same tax year, exceed 55% of the after-tax income of Wesbanco
     for the tax year in which paid;
<PAGE>
 
        (j) Business has been conducted by Wesbanco in the ordinary course and
     in a manner consistent with past practice;

        (k) There has been no change in the Articles of Incorporation or Bylaws
     of Wesbanco which would in the reasonable opinion of Commercial have a
     material adverse effect on the rights of holders of Wesbanco Common Stock;
     and

        (l) There has not been any other event, condition or development of any
     kind which materially and adversely affects the material assets, financial
     condition or results of operations of Wesbanco or any of its subsidiaries,
     and neither Wesbanco nor any of its subsidiaries have knowledge of any such
     event, condition or development which may materially and adversely affect
     the material assets, financial condition or results of operations of
     Wesbanco and its subsidiaries.

     8.21  Fidelity Bonds.  Each of the Wesbanco Subs has continuously
maintained fidelity bonds insuring it against acts of dishonesty by each of its
officers and employees in such amounts as are required by law and as are
customary, usual and prudent for a bank of its size.  Since January 1, 1997,
there have been no claims under such bonds (except as may be disclosed in the
Wesbanco Disclosure Schedule) and, except as disclosed in writing to Commercial,
neither Wesbanco nor any Wesbanco Subs are aware of any facts which would form
the basis of a claim under such bonds.  Neither Wesbanco nor any Wesbanco Subs
have any reason to believe that any fidelity coverage will not be renewed by
their carriers on substantially the same terms as the existing coverage.

     8.22  ERISA.  Except as disclosed in the Wesbanco Disclosure Schedule (i)
each employee benefit plan subject to Titles I and/or IV of ERISA and
established or maintained for persons including employees or former employees of
Wesbanco, or any of its subsidiaries, (hereinafter referred to as "Plan") has
been maintained, operated, administered and funded in accordance with its terms
and with all material provisions of ERISA and the IRC applicable thereto; (ii)
no event reportable under Section 4043 of ERISA has occurred and is continuing
with respect to any Plan; (iii) no liability to PBGC has been incurred with
respect to any Plan, other than for premiums due and payable and all premiums
required  to have been paid to PBGC as of the date hereof have been and as of
the Effective Date will have been paid; (iv) other than the termination of the
defined benefit pension plans of Wheeling Dollar Bank, First National Bank and
Trust Company, Wirt County Bank, First-Tyler Bank & Trust Company, Brooke
National Bank, First National Bank of Barnesville, Albright National Bank and
Bank of Weirton, no Plan has been terminated, no proceedings have been
instituted to terminate any Plan, and no decision has been made to terminate or
institute proceedings to terminate any Plan; (v) with respect to the termination
of the defined benefit pension plans of  Wheeling Dollar Bank, First National
Bank and Trust Company, Wirt County Bank, First-Tyler Bank & Trust Company,
Brooke National Bank, First National Bank of Barnesville, Albright National Bank
and Bank of Weirton, all required governmental and regulatory approvals of such
terminations have been obtained, all participants in such Plans or their
beneficiaries have received single premium annuity contracts or other benefits
which will provide those participants or beneficiaries with the retirement
income calculated under the terms and conditions of such Plans, all liabilities
of such Plans have been paid, released, discharged or merged, and any surplus
assets remaining in such Plans after satisfaction of all of its liabilities have
been recovered by Wesbanco or its subsidiaries; (vi) neither Wesbanco nor any of
its subsidiaries currently are a participating employer in any multi-employer or
multiple employer employee benefit pension plan (including any multi-employer
plans as defined in Section 3(37) of ERISA) and, with respect to any multi-
employer or multiple employer plan in which Wesbanco or any of its subsidiaries
was a participating employer, all contributions due from Wesbanco or any of its
subsidiaries to any such multi-employer or multiple employer plan have been
timely paid and any additional contributions due on or before the Effective Date
shall have been paid; (vii) with respect to any multi-employer pension plan
subject to the Multi-Employer Pension Plan Amendments Act of 1980 in which
Wesbanco or any of its subsidiaries was a participating employer, neither
Wesbanco nor any of its subsidiaries have incurred or will incur any withdrawal
liability, complete or partial, under Section 4201, 4203, or 4205 of ERISA, as a
consequence of discontinuing participating in such multi-employer pension plan;
<PAGE>
 
(viii) there has been no cessation of, and no decision has been made to cease,
operations at a facility or facilities where such cessation could reasonably be
expected to result in a separation from employment of more than 20% of the total
number of employees who are participants under any Plan; (ix) each Plan which is
an employee pension plan meets the requirements of "qualified plans" under
Section 401(a) of the IRC; (x) no accumulated funding deficiency within the
meaning of Section 412 of the IRC or Section 302 of ERISA has been incurred with
respect to any Plan subject to the funding standards of those provisions; (xi)
with respect to each Plan, there have been no prohibited transactions as defined
in Section 406 of ERISA or Section 4975 of the IRC, and there are no actions,
suits or claims with respect to the assets thereof (other than routine claims
for benefits) pending or threatened; and (xii) all required reports,
descriptions and notices (including, but not limited to, Form 5500 Annual
Reports, Summary Annual Reports and  Summary Plan Descriptions) have been
appropriately filed with the government or distributed to participants with
respect to each Plan.

     8.23  Labor Disputes. Neither Wesbanco nor any of its subsidiaries are
directly or indirectly involved in or threatened with any labor dispute,
including, without limitation, matters regarding discrimination by reason of
race, creed, sex, handicap or national origin, which would materially and
adversely effect their financial condition, assets, businesses or operations
taken as a whole.  No collective bargaining representatives represent any
Wesbanco, CBI or Wesbanco Subs employees and no petition for election of any
collective bargaining representative has been filed and, to the knowledge of
Wesbanco and its subsidiaries, no organizational campaign on behalf of any
collective bargaining unit has been undertaken by or on behalf of any Wesbanco,
CBI or Wesbanco Subs employees.

     8.24  Reserve for Possible Loan Losses.  The reserve for possible loan
losses shown on the consolidated balance sheets of Wesbanco and its subsidiaries
as of December 31, 1997, and June 30, 1997, delivered pursuant to this Agreement
is adequate in all material respects as of the dates thereof.

     8.25  Additional Covenants.  Except as otherwise contemplated by this
Agreement, Wesbanco covenants and agrees:

        (a) That it will use its best efforts in good faith to take, or cause to
     be taken all action required under this Agreement on its part, or CBI's
     part, to be taken as promptly as practicable so as to permit the
     consummation of the Merger at the earliest possible date and to cooperate
     fully with the other parties to that end, and that it will, in all such
     efforts, give priority to this acquisition of Commercial;

        (b) To deliver to Commercial all Forms 10-K, 10-Q and 8-K filed for
     periods ending after the date of this Agreement within seven (7) days after
     the filing of each such report with the SEC;

        (c) To promptly advise Commercial of any material adverse change in the
     financial condition, assets, businesses or operations of Wesbanco or any of
     its subsidiaries, or any material changes or inaccuracies in data provided
     to Commercial pursuant to this Agreement or any "acquisition proposal" with
     respect to Wesbanco received by Wesbanco;

        (d) To cooperate with Commercial in furnishing such information
     concerning the business and affairs of Wesbanco and its subsidiaries and
     its directors and officers as is reasonably necessary or requested in order
     to prepare and file any application for regulatory or governmental
     approvals, including but not limited to an application to the Federal
     Reserve Board and the West Virginia Department of Banking for prior
     approval of the acquisition of Commercial by Wesbanco as contemplated
     hereunder. Wesbanco will use its best efforts to obtain the approval or
     consent of any federal, state or other regulatory agency having
     jurisdiction and of any other party to the extent that such approvals or
     consents are required to effect the Merger and the transactions
     contemplated hereby or are required with respect to the documents described
     in Section 8.4 hereof; and

        (e) To cooperate with Commercial in furnishing such information
     concerning the business of Wesbanco and its subsidiaries as is reasonably
     necessary or requested in order to prepare any Proxy Statement to be
     prepared in connection with the Merger.
<PAGE>
 
                                   SECTION 9
                                 INVESTIGATION

     Subject to the conditions set forth in this Section 9, prior to the
Effective Time, Wesbanco and Commercial may directly and through their
representatives, make such investigation of the assets and business of Wesbanco
and Commercial and their subsidiaries as each deems necessary or advisable.
Wesbanco and Commercial and their representatives, including their accountants,
shall have, at reasonable times after the date of execution by Wesbanco and
Commercial hereof, full access to the premises and to all the property,
documents, material contracts, books and records of each, and its subsidiaries,
and to all documents, information and working papers concerning each held by
such party's accountants, without interfering in the ordinary course of business
of such entity, and the officers of each will furnish to the other such
financial and operating data and other information with respect to the business
and properties of each other and their subsidiaries as each shall from time to
time reasonably request; provided, however, that neither party shall be required
to give such access or information to the other party to the extent that it is
prohibited therefrom by rule, regulation, or order of any regulatory body, and
further provided that confidential information of individual banking customers
shall not be photocopied or removed from the premises of such institution.  All
data and information received by Wesbanco and its authorized representatives
from Commercial and by Commercial and its authorized representatives from
Wesbanco shall be held in strict confidence by such party and its authorized
representatives, and neither party nor its authorized representatives will use
such data or information or disclose the same to others except with the written
permission of the other party.  For a period of 7 days after the date of
execution hereof, or prior completion of the investigation herein provided, this
Agreement may be terminated by each such corporation if such investigation
reveals to the other any information concerning the other which in the opinion
of such corporation would have a material adverse effect on the present or
future value of the other such corporation and its subsidiaries' assets, net
worth, business or income taken as a whole.  Each such corporation shall provide
prompt written notice to the other of such decision and the matters relied on
therefore.

                                   SECTION 10
                 NON-SURVIVAL OF REPRESENTATIONS AND WARRANTIES
     The representations and warranties included or provided herein shall not
survive the Effective Date.

                                   SECTION 11
             CONDITIONS PRECEDENT; CLOSING DATE AND EFFECTIVE DATE
     11.1  Conditions Precedent of Wesbanco and Commercial.  The consummation of
this Agreement by Wesbanco and Commercial and the Merger is conditioned upon the
following:

        (a) The shareholders of Commercial, CBI and Wesbanco shall have approved
     this Agreement by such vote as required by law;

        (b) The West Virginia Banking Board (i) shall have granted its final
     approval of the incorporation and organization of CBI as a West Virginia
     corporation and the Merger and (ii) shall not, within 120 days from the
     date of Wesbanco's submission to the Banking Board pursuant to West
     Virginia Code Section 31A-8A- 4(a), have entered an order disapproving the
     acquisition of Commercial by Wesbanco pursuant to this Agreement;

        (c) The Secretary of State of West Virginia shall have issued a
     Certificate of Incorporation for CBI;

        (d) The Board of Governors of the Federal Reserve System shall have
     approved the application of Wesbanco to acquire Commercial; and of CBI to
     become a bank holding company pursuant to this Agreement;
<PAGE>
 
        (e) The Registration Statement of Wesbanco shall still be effective on
     the date of the Closing and all post-effective amendments filed shall have
     been declared effective or shall have been withdrawn by that date. No stop
     orders suspending the effectiveness thereof shall have been issued which
     remain in effect on the date of the Closing or shall have been threatened,
     and no proceedings for that purpose shall, before the Closing, have been
     initiated or, to the knowledge of Wesbanco, threatened by the SEC. All
     state securities and "Blue Sky" permits or approvals required (in the
     opinion of Wesbanco and Commercial to carry out the transaction
     contemplated in this Agreement) shall have been received.

        (f) No order to restrain, enjoin or otherwise prevent the consummation
     of the transaction contemplated in this Agreement shall have been entered
     by any court or administrative body which remains in effect on the date of
     the Closing.

        (g) Wesbanco, Commercial and CBI shall have received, in form and
     substance satisfactory to Wesbanco's and Commercial's counsel, all
     consents, federal, state, governmental, regulatory and other approvals and
     permissions and the satisfaction of all the requirements prescribed by law
     which are necessary to the carrying out of the transactions contemplated
     hereby shall have been procured, including the filing of an effective
     Registration Statement with the Securities and Exchange Commission and the
     West Virginia Securities Commissioner, and in addition, Wesbanco and
     Commercial shall have received any and all consents required with respect
     to the documents described pursuant to Section 7.3 and Section 8.4 hereof;

        (h) All delay periods and all periods for review, objection or appeal of
     or to any of the consents, approvals or permissions required with respect
     to the consummation of the Merger and this Agreement shall have expired;

        (i) Unless waived by Wesbanco and Commercial, the holders of not more
     than ten percent (10%) of the Voting Shares (as defined in Section 6.1
     hereof) shall have filed written objections to the Agreement in accordance
     with the WVCA, not have voted in favor of the Agreement at the special
     meeting of Commercial shareholders referred to in Section 13.1 hereof and
     have made written demand for the fair value of such Voting Shares within
     ten days;

        (j) On or before the Closing Date, there shall have been received an
     opinion from Kirkpatrick & Lockhart, LLP in a form reasonably satisfactory
     to counsel for Commercial substantially to the effect that for Federal
     Income Tax purposes:

                (i) The statutory merger of Commercial with CBI will constitute
          a reorganization within the meaning of Section 368(a)(1) of the
          Internal Revenue Code of 1986 ("IRC"), and Wesbanco, Commercial and
          CBI will each be a "party to the reorganization" as defined in IRC
          Section 368(b);

                (ii) No gain or loss will be recognized by Wesbanco, Commercial
          or CBI as a result of the transactions contemplated in the Agreement;

                (iii) No gain or loss will be recognized by the shareholders of
          Commercial as a result of their exchange of Commercial Common Stock
          for Wesbanco Common Stock, except to the extent any shareholder
          receives cash in lieu of a fractional share or as a dissenting
          shareholder;

                (iv) The holding period of the Wesbanco Common Stock received by
          each holder of Commercial Common Stock will include the period during
          which the stock of Commercial surrendered in exchange therefor was
          held, provided such stock was a capital asset in the hands of the
          holder on the date of exchange; and

                (v) The Federal Income Tax Basis of the Wesbanco Common Stock
          received by each holder of Commercial Common Stock will be the same as
          the basis of the stock exchanged therefore.

        (k) No action, proceeding, regulation or legislation shall have been
     instituted before any court, governmental agency or legislative body to
     enjoin, restrain or prohibit, or to obtain substantial damages with respect
     to, the Agreement or the consummation of the transactions contemplated
     hereby, which, in the reasonable judgment of Wesbanco or Commercial, would
     make it inadvisable to consummate such transactions (it being understood
     and agreed that a written request by governmental authorities for
     information with respect to the Merger may not be deemed by either party to
     be a threat of material litigation or proceeding, regardless of whether
     such request is received before or after execution of the Agreement).
<PAGE>
 
        (l) The approvals referred to in subparagraphs (b), (c) and (d) of
     Subsection 11.1 herein shall not have required the divestiture or cessation
     of any material part of the present operations conducted by Wesbanco,
     Commercial or any of their subsidiaries, and shall not have imposed any
     other condition, which divestiture, cessation or condition Wesbanco
     reasonably deems to be materially disadvantageous or burdensome.

     11.2  Conditions Precedent of Wesbanco.  The consummation of this Agreement
by Wesbanco and the Merger is also conditioned upon the following:
     
        (a) Unless waived by Wesbanco, the representations and warranties of
     Commercial contained in this Agreement shall be correct on and as of the
     Effective Date with the same effect as though made on and as of such date,
     except for representations and warranties expressly made only as of a
     particular date and except for changes which have been consented to by
     Wesbanco or which are not, in the aggregate, material and adverse, to the
     financial condition, businesses, properties or operations of Commercial and
     its Subsidiaries taken as a whole, or which are the result of expenses or
     transactions contemplated or permitted by the Agreement, and Commercial
     shall have performed in all material respects all of its obligations and
     agreements hereunder theretofore to be performed by it; and Wesbanco and
     CBI shall have received on the Effective Date an appropriate certificate
     (in affidavit form) dated the Effective Date and executed on behalf of
     Commercial by one or more appropriate executive officers of Commercial to
     the effect that such officers have no knowledge of the non-fulfillment of
     the foregoing condition;

        (b) Opinion of Commercial Counsel. An opinion of counsel from the law
     firm of Hunton & Williams, counsel for Commercial, shall have been
     delivered to Wesbanco, dated the Closing Date, and in form and substance
     satisfactory to Wesbanco and its counsel, to the effect that:

                (i) Commercial is a corporation duly organized, validly existing
          and in good standing under the laws of the State of West Virginia and
          has the full corporate power and authority to own all of its
          properties and assets and to carry on its business as it is now being
          conducted, and neither the ownership of its property nor the conduct
          of its business requires it, or its Subsidiaries, to be qualified to
          do business in any other jurisdiction except where the failure to be
          so qualified, considering all such cases in the aggregate, does not
          involve a material risk to the business, properties, financial
          position or results of operations of Commercial and its Subsidiaries,
          taken as a whole.

                (ii) Commercial has the full corporate power to execute and
          deliver the Agreement and Plan of Merger. All corporate action of
          Commercial required to duly authorize the Agreement and Plan of Merger
          and the actions contemplated thereby has been taken, and the Agreement
          and Plan of Merger is valid and binding on Commercial in accordance
          with its terms, subject, as to the enforcement of remedies, to
          applicable bankruptcy, insolvency, moratorium, or other similar laws
          affecting the enforcement of creditors' rights generally from time to
          time in effect, and subject to any equitable principles limiting the
          right to obtain specific performance of certain obligations
          thereunder.

                (iii) All shares of common stock of Commercial issued and
          outstanding as of the Effective Date are duly authorized, validly
          issued, fully paid and nonassessable.

                (iv) The consummation of the merger contemplated by the
          Agreement and Plan of Merger will not violate any provision of
          Commercial's Articles of Incorporation or Bylaws, or violate any
          provision of, or result in the acceleration of any material obligation
          under, any material mortgage, loan agreement, order, judgment, law or
          decree known to such counsel to which Commercial is a party or by
          which it is bound and will not violate or conflict with any other
          material restriction of any kind or character known to such counsel to
          which Commercial is subject, which would have a materially adverse
          effect on the assets, business or operations of Commercial, taken as a
          whole.

                (v) Commercial's Subsidiaries are West Virginia and Ohio
          corporations and are duly organized, validly existing and in good
          standing under the laws of the States of West Virginia and Ohio and
          have the requisite corporate power and authority to own and lease
          their properties and to conduct their businesses as they are now being
          conducted. To the best of such counsel's knowledge, Commercial owns
          100% of the issued and outstanding stock of such corporations.
<PAGE>
 
                (vi) To the best of such counsel's knowledge, as of the date
          hereof neither Commercial nor its Subsidiaries were involved in any
          litigation against them (with possible exposure of $100,000.00 or
          more), pending or threatened, that has not been disclosed to Wesbanco.

                (vii) The rights issued to shareholders of Commercial pursuant
          to the Shareholder Rights Plan adopted by Commercial on August 14,
          1996 (the "Rights Plan") have been redeemed in accordance with the
          terms of the Rights Plan. The right to exercise the rights and the
          Rights Plan have been terminated in accordance with the provisions of
          such plan, with no further obligations to the shareholders of
          Commercial, and are no longer in force or effective.

        (c) Unless waived by Wesbanco, on or before the Effective Date, Ernst &
     Young, LLP, the independent auditors for Wesbanco, shall have rendered an
     opinion to Wesbanco that the Merger will be treated as a "pooling of
     interest" for accounting purposes.

        (d) Commercial shall have delivered to Wesbanco a schedule identifying
     all persons who may be deemed to be "affiliates" of Commercial under Rule
     145 of the Securities Act of 1933, as amended, and shall use its best
     efforts to cause each affiliate to deliver to Wesbanco prior to the
     Effective Date a letter substantially in the form attached hereto as
     Exhibit "A".

        (e) William E. Mildren, Jr., Larry G. Johnson, W. Bryan Pennybacker,
     James A. Meagle, Jr., Thomas M. Lookbaugh and C. Randall Law shall have
     duly executed and delivered employment agreements with Commercial and/or
     its Subsidiaries or successors, dated as of the Closing Date, in
     substantially the form attached hereto as Exhibits B, C, D, E, F and G.

        (f) Commercial shall have furnished Wesbanco with a certified copy of
     resolutions duly adopted by the Board of Directors and the shareholders of
     Commercial approving the Agreement and authorizing the Merger and the
     transactions contemplated hereby.

        (g) Unless waived by Wesbanco, on the Closing Date, there shall not be
     pending against Commercial or its Subsidiaries or the officers or directors
     of Commercial or its Subsidiaries in their capacity as such, any suit,
     action or proceeding, including the case styled Citizens Bancshares, Inc.
     v. Commercial Bancshares, Inc. filed in the United States District Court
     for the Northern District of Ohio, Eastern Division and the proposed
     intervention therein by Peoples Bancorp, Inc. and the Complaint filed by
     Peoples Bancorp, Inc. styled Peoples Bancorp, Inc. v. Commercial
     Bancshares, Inc. which, in the reasonable judgment of Wesbanco, if
     successful, could have a material adverse effect on the financial condition
     or operations of Commercial or its Subsidiaries.  For purposes of this
     subsection 11.2(g), the pendency at the Closing Date of the suits named
     above shall not constitute a failure of condition giving Wesbanco the right
     to terminate the Agreement pursuant to Section 12.1(b) unless (i)
     Wesbanco's Board of Directors, acting reasonably and upon the advice of
     counsel, concludes that such suits could result in a loss exposure to
     Commercial, including fees, expenses and damages of $250,000 or more, or
     (ii) injunctive relief or specific performance has been awarded to Citizens
     or Peoples or substantive requests for the same are pending, which
     injunctive relief or specific performance, in the judgment of Wesbanco's
     Board of Directors, acting reasonably and upon the advice of counsel, could
     materially hinder consummation of the Merger.

        (h) Commercial shall have executed and delivered to Wesbanco an Option
     Agreement, substantially in the form attached hereto as Exhibit H, dated
     the 12th day of September, 1997 (the "Option Agreement"), and incorporated
     herein by reference.

        (i) The rights issued under the Rights Plan shall have been redeemed in
     accordance with the terms of the Rights Plan.  The right to exercise the
     rights and the Rights Plan shall have been terminated in accordance with
     the provisions of such plan, with no further obligations to the
     shareholders of Commercial, and the rights and the Rights Plan are no
     longer in force or effective.  No right or claim pursuant to the Rights
     Plan shall have been made, alleged, or threatened by any shareholder of
     Commercial.

        (j) Unless waived by Wesbanco, Gateway Bancshares, Inc. shall have
     executed and delivered to Wesbanco the First Amendment Agreement modifying
     certain terms of that Agreement and Plan of Merger dated August 15, 1997,
     by and between Commercial, Gateway Bancshares, Inc. and CWV Holding
     Company, Inc., in the form, or substantially the form, attached hereto as
     Exhibit I and made a part hereof.
<PAGE>
 
     11.3  Conditions Precedent of Commercial.  The consummation of this
Agreement by Commercial and the Merger is also conditioned upon the following:
     
        (a) Unless waived by Commercial the representations and warranties of
     Wesbanco and CBI contained in this Agreement shall be correct on and as of
     the Effective Date with the same effect as though made on and as of such
     date, except for representations and warranties expressly made only as of a
     particular date and except for changes which have been consented to by
     Commercial or which are not in the aggregate material and adverse to the
     financial condition, businesses, properties or operations of Wesbanco and
     CBI or which are the result of expenses or transactions contemplated or
     permitted by this Agreement, and Wesbanco and CBI shall have performed in
     all material respects all of their obligations and agreements hereunder
     theretofore to be performed by them; and Commercial shall have received on
     the Effective Date an appropriate certificate (in affidavit form) dated the
     Effective Date and executed on behalf of Wesbanco and CBI by one or more
     appropriate executive officers of each of them to the effect that such
     officers have no knowledge of the non-fulfillment of the foregoing
     conditions;

        (b) Opinion of Wesbanco Counsel. An opinion of Phillips, Gardill, Kaiser
     & Altmeyer, counsel for Wesbanco, shall have been delivered to Commercial,
     dated the Closing Date, and in form and substance satisfactory to
     Commercial and its counsel, to the effect that:

                (i) Wesbanco and CBI are corporations duly organized, validly
          existing and in good standing under the laws of the State of West
          Virginia and have the full corporate power and authority to own all of
          their properties and assets and to carry on their businesses as they
          are now being conducted, and neither the ownership of their property
          nor the conduct of their businesses require them, or any of their
          subsidiaries, to be qualified to do business in any other jurisdiction
          except where the failure to be so qualified, considering all such
          cases in the aggregate, does not involve a material risk to the
          business, properties, financial position or results of operations of
          Wesbanco, CBI and the Wesbanco Subs, taken as a whole.

                (ii) Wesbanco and CBI have the full corporate power to execute
          and deliver the Agreement and Plan of Merger. All corporate action of
          Wesbanco and CBI required to duly authorize the Agreement and Plan of
          Merger and the actions contemplated thereby has been taken, and the
          Agreement and Plan of Merger is valid and binding on Wesbanco and CBI
          in accordance with its terms, subject, as to the enforcement of
          remedies, to applicable bankruptcy, insolvency, moratorium, or other
          similar laws affecting the enforcement of creditors' rights generally
          from time to time in effect, and subject to any equitable principles
          limiting the right to obtain specific performance of certain
          obligations thereunder.

                (iii) The shares of common stock of Wesbanco into which shares
          of common stock of Commercial shall be converted pursuant to the terms
          of the Agreement and Plan of Merger have been duly authorized, and
          when delivered pursuant to the terms of the Agreement and Plan of
          Merger, will have been legally and validly issued, and will be fully
          paid and nonassessable.

                (iv) The consummation of the merger contemplated by the
          Agreement and Plan of Merger will not violate any provision of
          Wesbanco's or CBI's Articles of Incorporation or Bylaws, or violate
          any provision of, or result in the acceleration of any material
          obligation under, any material mortgage, loan agreement, order,
          judgment, law or decree known to such counsel to which Wesbanco or CBI
          are a party or by which it is bound, and will not violate or conflict
          with any other material restriction of any kind or character known to
          such counsel to which Wesbanco or CBI are subject which would have a
          material adverse effect on the assets, business or operations of
          Wesbanco and CBI, taken as a whole.

                (v) Each of Wesbanco's subsidiaries is duly organized, validly
          existing and in good standing under the laws of the state of its
          organization and has the requisite corporate power and authority to
          own and lease its properties and to conduct its business as it is now
          being conducted. To the best of such counsel's knowledge, Wesbanco
          owns 100% of the issued and outstanding stock of each such
          corporation.

               (vi) To the best of such counsel's knowledge, as of the date
          hereof, neither Wesbanco nor any of its subsidiaries were involved in
          any litigation against them (with possible exposure of $100,000.00 or
          more), pending or threatened, that has not been disclosed to
          Commercial.
<PAGE>
 
                (vii) The Registration Statement for the stock to be delivered
          pursuant to the Agreement and Plan of Merger has become effective
          under the Securities Act of 1933, and such counsel is not aware of any
          stop orders in effect with regard to such Registration Statement.

        (c) Danielson Associates, Inc., financial advisors to Commercial, shall
     have furnished to Commercial an opinion, or an updating of any opinion
     rendered after the date of the Agreement, dated on or prior to the
     distribution date of the Proxy Statement described in Section 13.1 of this
     Agreement, and at the election of Commercial, updated as of the Closing if
     the Closing is held more than five (5) days after the Commercial meeting of
     shareholders, to the effect that the Merger and transactions contemplated
     by this Agreement are fair, from a financial point of view, to Commercial
     and its shareholders.

        (d) Wesbanco and CBI shall have furnished Commercial with certified
     copies of resolutions duly adopted by the Boards of Directors of Wesbanco
     and CBI and the shareholders of CBI approving the Agreement and authorizing
     the Merger and transactions contemplated hereby.

        (e) Unless waived by Commercial, on the Closing Date, there shall not be
     pending against Wesbanco or any of its subsidiaries or the officers or
     directors of Wesbanco or any of its subsidiaries in their capacity as such,
     any suit, action or proceeding which, in the reasonable judgment of
     Commercial, if successful, would have a material adverse effect on the
     financial condition or operations of Wesbanco or any of its subsidiaries.

        (f) Unless waived by Commercial, there shall not have been any change in
     control of Wesbanco since July 1, 1997.

        (g) Wesbanco shall assume the obligations of Commercial arising under
     the Change in Control Arrangements with William E. Mildren, Jr. and Larry
     G. Johnson dated November 1, 1996, as amended by Exhibits F and G.

     11.4  Closing Date.  The Closing shall be effected as soon as practicable
after all of the conditions contained herein shall have been satisfied on the
Closing Date as defined in Section 2.3 hereof, which Closing Date shall be the
latest of:

        (a) The day of the meetings of the shareholders of Commercial or
     Wesbanco, whichever is later, at which the Agreement is approved;

        (b) The fifteenth (15th) day after the approval of the acquisition of
     Commercial by the Board of Governors of the Federal Reserve System (the
     "Federal Reserve Board");

        (c) The day after any stay of the Federal Reserve Board's approval of
     the acquisition of Commercial shall be vacated or shall have expired or the
     day after any injunction against the closing of the Merger shall be lifted,
     discharged or dismissed;

        (d) The day after the approval of the acquisition of Commercial by the
     West Virginia Department of Banking is received by Wesbanco;

        (e) The date on which the conditions set forth in Section 11 are
     satisfied or waived;

        (f) Such other date as shall be mutually agreed to by Wesbanco and
     Commercial.

     The Closing shall be held in Parkersburg, West Virginia, at such time and
     place as the parties may agree upon.  The date and time of closing are
     herein called the "Closing Date".  Promptly after the Closing, the Articles
     of Merger with respect to the Merger shall be filed with the Secretary of
     State of West Virginia.

     11.5  Effective Date.  The Merger shall become effective (the "Effective
Date") on the date on which the Certificate of Merger approving the Merger is
issued by the Secretary of State of West Virginia.  The Surviving Corporation
shall record said Certificate of Merger in the office of the Clerk of the County
Commission of Wood County.
<PAGE>
 
                                   SECTION 12
                            TERMINATION OF AGREEMENT

     12.1  Grounds for Termination.  This Agreement and the transactions
contemplated hereby may be terminated at any time prior to the Closing Date
either before or after the meeting of the shareholders of Commercial:

     (a) By mutual consent of Commercial and Wesbanco;

     (b) By either Commercial or Wesbanco if any of the conditions hereto to
     such party's obligations to close have not been met as of the Closing Date
     and the same has not been waived by the party adversely affected thereby;

        (c) By either Commercial or Wesbanco if the Merger shall violate any 
     non-appealable final order, decree or judgment of any court or governmental
     body having competent jurisdiction;

        (d) By Commercial or Wesbanco, if the Closing Date has not occurred by
     March 31, 1998;

        (e) By Commercial, unless waived by Commercial, if the Market Value of
     Wesbanco stock shall fall below $25.00 per share as of the Closing Date.
     Market Value, for purposes of this paragraph, shall mean the average bid
     price of Wesbanco Common Stock (as quoted on NASDAQ) for the 30 calendar
     days preceding five business days before the Closing.

        (f) By either party in the event that the  shareholders of Commercial or
     the shareholders of Wesbanco vote against consummation of the Merger.

        (g) By Wesbanco or Commercial within 7 days of the date hereof pursuant
     to the provisions of Section 9 of this Agreement.

     12.2  Effect of Terminating; Right to Proceed.  In the event this Agreement
shall be terminated pursuant to Section 12.1, all further obligations of
Wesbanco and Commercial under this Agreement, except Sections 9, 12.1, 12.2, and
19 hereof, shall terminate without further liability of Wesbanco and CBI to
Commercial or of Commercial to Wesbanco and CBI.

     12.3  Return of Documents in Event of Termination.  In the event of
termination of this Agreement for any reason, Wesbanco and Commercial shall each
promptly deliver to the other all documents, work papers and other material
obtained from each other relating to the transactions contemplated hereby,
whether obtained before or after the execution hereof, including information
obtained pursuant to Section 9 hereof, and will take all practicable steps to
have any information so obtained kept confidential, and thereafter, except for
any breach of the continuing sections of the Agreement, each party shall be
mutually released and discharged from liability to the other party or to any
third parties hereunder, and no party shall be liable to any other party for any
costs or expenses paid or incurred in connection herewith.

                                   SECTION 13
               MEETING OF SHAREHOLDERS OF COMMERCIAL AND WESBANCO

     13.1  Subject to receipt by Commercial of the fairness opinion described in
Section 11.3(c) hereof, Commercial shall take all steps necessary to call and
hold a special meeting of its shareholders, in accordance with applicable law
and the Articles of Incorporation and Bylaws of Commercial as soon as
practicable (considering the regulatory approvals required to be obtained) for
the purpose of submitting this Agreement to its shareholders for their
consideration and approval and will send to its shareholders for purposes of
such meeting a Proxy Statement which will not contain any untrue statement of a
material fact with respect to Commercial or omit to state a material fact with
respect to Commercial required to be stated therein or necessary to make the
statements contained therein, in light of the circumstances under which they
were made, not misleading, and which otherwise materially complies as to form
with all applicable laws, rules and regulations.
<PAGE>
 
     13.2  Wesbanco shall take all steps necessary to call and hold a special
meeting of its shareholders, in accordance with applicable law and the Articles
of Incorporation and Bylaws of Wesbanco as soon as practicable (considering the
regulatory approvals required to be obtained) for the purpose of submitting this
Agreement to its shareholders for their consideration and approval and will send
to its shareholders for purposes of such meeting a Proxy Statement which will
not contain any untrue statement of a material fact with respect to Wesbanco or
omit to state a material fact with respect to Wesbanco required to be stated
therein or necessary to make the statements contained there, in light of the
circumstances under which they were made, not misleading, and which otherwise
materially complied as to form with all applicable laws, sales and regulations.

     13.3  It is understood that as an integral part of the transaction
contemplated by this Agreement, Wesbanco shall file a Registration Statement
with respect to the offering of its common shares to be issued in the Merger.
The term "Registration Statement" as used in this Agreement includes all
preliminary filings, post-effective amendments and any Proxy Statement of
Commercial and Wesbanco.  Accordingly, Wesbanco and Commercial agree to assist
and cooperate fully with each other in the preparation of the Registration
Statement.  Both Commercial and Wesbanco further agree to deliver to each other,
both as of the Effective Date of the Registration Statement and as of the
Closing, a letter, in form and substance satisfactory to the other party and its
counsel, stating that, to the best of their knowledge and belief, all of the
facts with respect to either Wesbanco or Commercial, as the case may be, set
forth in the Registration Statement, are true and correct in all material
respects, and that the Registration Statement does not omit any material fact
necessary to make the facts stated therein with respect to such party not
misleading in light of the circumstances under which they were made.

                                  SECTION 14
                                    BROKERS
Commercial represents and warrants to Wesbanco and Wesbanco represents and
warrants to Commercial that no broker or finder has been employed, or is
entitled to a fee, commission or other compensation, with respect to this
Agreement or the transactions contemplated hereby, other than fees due from
Commercial to Danielson Associates, Inc., its financial advisor.

                                  SECTION 15
                         GOVERNING LAW; SUCCESSORS AND
                    ASSIGNS; COUNTERPARTS; ENTIRE AGREEMENT

     This Agreement (a) shall be governed by and construed under and in
accordance with the laws of the State of West Virginia; (b) shall be binding
upon and shall inure to the benefit of the parties hereto and their respective
successors and assigns, provided, however, that this Agreement may not be
assigned by any party without the written consent of the other parties hereto;
(c) may be executed in one or more counterparts, all of which shall be
considered one and the same agreement, and shall become effective and binding as
to Wesbanco and Commercial  when one or more counterparts shall have been signed
and delivered by Wesbanco and Commercial and shall become effective and binding
as to CBI when CBI receives its Certificate of Incorporation and its officers
execute the Agreement; and (d) embodies the entire Agreement and understanding
of the parties with respect to the subject matter hereof; and (e) supersedes all
prior agreements and understandings, written or oral, between Commercial and
Wesbanco relating to the subject matter hereof.

                                  SECTION 16
                              EFFECT OF CAPTIONS
     The captions of this Agreement are included for convenience only and shall
not in any way affect the interpretation or construction of any of the
provisions hereof.
<PAGE>
 
                                  SECTION 17
                                    NOTICES
     Except as specifically provided in Section 7.21(d) hereof, any notices or
other communication required or permitted hereunder shall be sufficiently given
if delivered personally or sent by first class, registered or certified mail
postage prepaid, with return receipt requested addressed as follows:

     To Commercial:
        Commercial Bancshares, Incorporated
        415 Market Street
        Parkersburg, WV 26101
        ATTENTION:  William E. Mildren, Jr., President

     With a copy to:
        Hunton & Williams
        951 East Byrd Street
        Richmond, Virginia 23219-4074
        ATTENTION: Lathan M. Ewers, Esq.

     To Wesbanco:
        Wesbanco, Inc.
        One Bank Plaza
        Wheeling, WV  26003
        ATTENTION:  Edward M. George, President

     With a copy to:
        Phillips, Gardill, Kaiser & Altmeyer
        61 Fourteenth Street
        Wheeling, WV  26003
        ATTENTION:  James C. Gardill, Esq.

or such other addresses as shall be furnished in writing by either party to the
other party.  Any such notice or communication shall be deemed to have been
given as of the date so mailed.

                                  SECTION 18
                                  AMENDMENTS

     Any of the terms or conditions of the Agreement may be waived at any time
by the party which is, or the shareholders of which are, entitled to the benefit
thereof, by action taken by the Board of Directors of such party, or any of such
terms or conditions may be amended or modified in whole or in part at any time
as follows.  This Agreement may be amended in writing (signed by all parties
hereto) before or after the meeting of Commercial shareholders at any time prior
to the Closing Date with respect to any of the terms contained herein, provided,
however, that if amended after such meeting of shareholders, the conversion
ratio per share at which each share of common stock of Commercial shall be
converted in the Merger and any other material terms of the Merger shall not be
amended after the meeting of Commercial shareholders unless the amended terms
are resubmitted to the shareholders for approval.  Neither the Agreement nor any
provisions hereof, may be changed, waived, discharged or terminated orally, or
by the passage of time, except by a statement in writing signed by the party
against which the enforcement of such change, waiver, discharge or termination
is sought.

                                  SECTION 19
                                   EXPENSES

     Each party to this Agreement shall pay its own legal and accounting fees
and other costs and expenses incurred in connection with this Agreement and the
transactions contemplated hereby.
<PAGE>
 
                                  SECTION 20
                                 MISCELLANEOUS
     20.1  Publicity.  The parties will not publicly release any information
about the transactions contemplated hereby except as they may mutually agree or
as may be required by law.

     20.2  Incorporation by Reference.  Any and all schedules, exhibits,
annexes, statements, reports, certificates or other documents or instruments
referred to herein or attached hereto are incorporated herein by reference as
though fully set forth at the point referred to in the Agreement.

     20.3  Material Adverse Change.  In determining whether there has been a
material adverse change for purposes of this Agreement, costs and expenses of
the transactions contemplated hereby shall not be taken into account provided,
however, that only the first $50,000 of such expenses shall be so excluded.

     20.4  Binding Date.  This Agreement is effective and binding as to Wesbanco
and Commercial upon the date first above written and effective and binding as to
CBI upon execution hereof by CBI.

     IN WITNESS WHEREOF, Wesbanco and Commercial have each caused this Agreement
to be executed on its behalf by its officers thereunto duly authorized all as of
the day and year first above written and CBI has caused this Agreement to be
executed on its behalf by its officers thereunto duly authorized as of the date
set forth below.

                             WESBANCO, INC., a West Virginia
                             corporation


                             By /s/ E. M. George
                                       Its President

(SEAL)


ATTEST:

/s/ Shirley A. Bucan
       Secretary

                             COMMERCIAL BANCSHARES,
                             INCORPORATED, a West Virginia corporation


                             By /s/ William E. Mildren, Jr.
                                     Its President


(SEAL)



ATTEST:

/s/ Larry G. Johnson
      Secretary
<PAGE>
 
                             CBI CORPORATION, a West Virginia
                             corporation as of the ____ day of ____________,
                             19___.


                             By_______________________________________
                                      Its _______________________


(SEAL)



ATTEST:

__________________________
      Secretary


 
<PAGE>
 
                                   EXHIBIT A

                                AFFILIATE LETTER


Wesbanco, Inc.
Bank Plaza
Wheeling, WV  26003

Gentlemen:

     Reference is made to the Agreement and Plan of Merger (the "Agreement"),
dated as of the _____ day of ____________, 1997, by and between Wesbanco, Inc.
("Wesbanco") and Commercial Bancshares, Incorporated ("Commercial") providing
for the merger ("Merger") of Commercial with CBI Corporation ("CBI"), a wholly
owned subsidiary of Wesbanco, whereby Wesbanco shall acquire all of the
outstanding common stock of Commercial  through and as a result of such Merger
in exchange for shares of the common stock of Wesbanco.  The undersigned
stockholder of Commercial has been identified as a person who may be an
"Affiliate" of Commercial for purposes of Rule 145 of the Securities Act of
1933, as amended (the "Act").  As a result of the transactions contemplated by
the Agreement, the undersigned stockholder will receive shares of Wesbanco
stock.  In consideration of the receipt of such shares, the undersigned
stockholder warrants and covenants as follows:

     (1)   Until the expiration of the limitation on the transfer  as provided
in Rule 145 of the shares of Wesbanco Common Stock received as a result of the
Merger, the undersigned stockholder will not sell, transfer or assign, and
Wesbanco shall not be required to give effect to any attempted sale, transfer or
assignment, except pursuant to (i) a Registration Statement then in effect under
the Act, (ii) a transaction permitted by Rule 145 as to which Wesbanco has
received evidence of compliance with the provisions of Rule 145 reasonably
satisfactory to it, or (iii) a transaction which, in the opinion of counsel or
as described in a "no action" or interpretive letter from the staff of the
Securities and Exchange Commission, in either case in form and substance
reasonably satisfactory to Wesbanco, is exempt from or otherwise complies with
the registration requirements of the Act.

     (2)   Until the expiration of any limitation on the transfer of the
Wesbanco Common Stock as provided in Rule 145(d), each certificate the
undersigned receives for Wesbanco Common Stock as a result of the Merger may
bear a restrictive legend in substantially the following form:
<PAGE>
 
     "The shares represented by this certificate have been issued to the
registered holder as a result of a transaction to which Rule 145 under the
Securities Act of 1933 (the "Act") as amended, applies.  The shares represented
by this certificate may not be sold, transferred, or assigned, and the issuer
shall not be required to give effect to any attempted sale, transfer or
assignment, except pursuant to (i) the Registration Statement then in effect
under the Act, (ii) a transaction permitted by said Rule 145 reasonably
satisfactory to it, or (iii) a transaction which, in the opinion of counsel or
as described in a `no action' or interpretive letter from the staff of the
Securities and Exchange Commission, in each case satisfactory in form and
substance to the issuer, is exempt from the registration requirements of the
Act."

                                     Very truly yours,


                                     _____________________________________


ACCEPTED this _____ day of
_______________, 1997.

WESBANCO, INC.


By________________________
     Its________________