<PAGE>   1








                                                             EXHIBIT 99.3

                         STOCK OPTION AGREEMENT

      THIS STOCK OPTION AGREEMENT (this "Option Agreement"), dated as of
March 24, 1997, is by and between COMMUNITY BANKSHARES, INC.
("Community"), a New Hampshire corporation, and CFX CORPORATION ("CFX"),
a New Hampshire corporation.

                               WITNESSETH

      WHEREAS, the respective Boards of Directors of Community and CFX
have approved a Plan of Share Exchange (the "Plan of Exchange"), and the
respective Boards of Directors of Community, Concord Savings Bank
("Concord Bank"), a New Hampshire state-chartered savings bank subsidiary
of Community, Centerpoint Bank ("Centerpoint Bank"), a New Hampshire
state-chartered commercial bank subsidiary of Community, CFX and CFX
Bank, a New Hampshire state-chartered savings bank subsidiary of CFX,
have approved an Agreement and Plan of Reorganization (the
"Reorganization Agreement") and an Agreement and Plan of Merger (the
"Plan of Merger" and, together with the Plan of Exchange, the
Reorganization Agreement and certain other agreements contemplated by the
Reorganization Agreement, the "Transaction Documents"), providing for
certain transactions pursuant to which CFX would acquire all the
outstanding capital stock of Community through a share exchange,
Community would be merged with and into CFX, and Concord Bank and
Centerpoint Bank would be merged with and into CFX Bank (collectively,
the "Transactions");

      WHEREAS, as a condition to CFX's entry into the Transaction
Documents and the Transactions, and to induce such entry, Community has
agreed to grant CFX the option set forth herein to purchase authorized
but unissued shares of Community Common Stock;

      NOW, THEREFORE, in consideration of the premises herein contained,
the parties agree as follows:

      1.    Certain Definitions.

            (a)   Capitalized terms used but not defined herein shall
have the same meanings as in the Transaction Documents.

            (b)   The term "Effective Date" shall have the meaning
specified in the Reorganization Agreement.

            (c)   The term "person" shall have the meanings specified in
Sections 3(a)(9) and 13(d)(3) of the Exchange Act, and shall also include
persons (other than Community, any Community subsidiary, CFX, or any CFX
affiliate), who have entered into an agreement, arrangement or
understanding (whether or not in writing), or who are acting in concert
<PAGE>   2







or with conscious parallel behavior, for the purpose of acquiring,
holding, voting or disposing of any voting securities of Community
(except pursuant solely to a revocable proxy given in response to a
public proxy or consent solicitation made pursuant to, and in accordance
with, the applicable provisions of the Exchange Act and the regulations
promulgated thereunder).

            (d)   The term "Purchase Event" shall mean any of the
following events or transactions occurring after the date hereof:

                  (1)   any person (other than Community, any Community
subsidiary, CFX, or any CFX affiliate) shall have commenced (as such term
is defined in Rule 14d-2 under the Exchange Act), or shall have filed a
registration statement under the Securities Act with respect to, a bona
fide tender or exchange offer to purchase shares of Community Common
Stock such that upon consummation of such offer such person would own or
control 15 percent or more of the outstanding shares of Community Common
Stock;

                  (2)   any person (other than Community, any Community
subsidiary, CFX, or any CFX affiliate), other than in connection with a
transaction to which CFX has given its prior written consent, shall have
filed an application or notice with any federal or state regulatory
agency for clearance or approval, to (i) merge or consolidate, or enter
into any similar transaction, with Community or any Community subsidiary,
(ii) purchase, lease or otherwise acquire all or substantially all the
assets of Community or any Community subsidiary, or (iii) purchase or
otherwise acquire (including by way of merger, consolidation, share
exchange or any similar transaction) securities representing 15 percent
or more of the voting power of Community or any Community subsidiary;

                  (3)   any person (other than Community, any Community
subsidiary, subsidiaries of Community in a fiduciary capacity, CFX,
affiliates of CFX, or subsidiaries of CFX in a fiduciary capacity) shall
have acquired beneficial ownership or the right to acquire beneficial
ownership of 15 percent or more of the outstanding shares of Community
Common Stock (the term "beneficial ownership" for purposes of this Option
Agreement having the meaning assigned thereto in Section 13(d) of the
Exchange Act and the regulations promulgated thereunder);

                  (4)   any person (other than Community, any Community
subsidiary, CFX or any CFX affiliate) shall have made a bona fide
proposal to Community by public announcement or written communication
that is or becomes the subject of public disclosure to (i) acquire
Community or any Community subsidiary by merger, consolidation, purchase
of all or substantially all its assets or any other similar transaction,
or (ii) make an offer described in clause (1) above; or

                  (5)   Community shall have willfully breached any
Specified Covenant (as defined below), which breach would entitle CFX to


                                  - 2 -
<PAGE>   3







terminate the Transaction Documents (without regard to the cure periods
provided for therein) and such breach shall not have been cured prior to
the Notice Date (as defined below).


            (e)   The term "Repurchase Event" shall mean any of the
following:

                  (1)   any person (other than Community, any Community
subsidiary, CFX, or any CFX affiliate) shall have acquired beneficial
ownership of 25 percent or more of the outstanding shares of Community
Common Stock; or

                  (2)   any person (other than CFX or any CFX affiliate)
shall have entered into an agreement, arrangement or understanding
(whether or not in writing) with Community or any Community subsidiary to
(i) merge or consolidate, or enter into any similar transaction, with
Community or any Community subsidiary, (ii) purchase, lease or otherwise
acquire all or substantially all the assets of Community or any Community
subsidiary, or (iii) purchase or otherwise acquire (including by way of
merger, consolidation, share exchange or any similar transaction)
securities representing 25 percent or more of the voting power of
Community or any Community subsidiary.

            (f)   The term "Specified Covenant" shall mean any covenant
contained in Sections 4.1, 4.2, 4.3, 4.4 or 4.8 or subsections (2), (3),
(4), (5), (6), (7), (11), (16) and, to the extent applicable to the
foregoing subsections, (17) of Section 4.7(b) of the Reorganization
Agreement.

      2.    Grant of Option.  Subject to the terms and conditions set
forth herein, Community hereby grants to CFX an option (the "Option") to
purchase up to 493,000 shares of Community Common Stock at a price of
$28.50 per share payable in cash as provided in Section 4 hereof;
provided, however, that in the event Community issues or agrees to issue
any shares of Community Common Stock in breach of its obligations under
the Transaction Documents at a price less than $28.50 per share (as
adjusted pursuant to Section 6 hereof), the exercise price shall be equal
to such lesser price.

      3.    Exercise of Option.

            (a)  If not then in material breach of the Transaction
Documents, CFX may exercise the Option, in whole or part, at any time or
from time to time if a Purchase Event shall have occurred and be
continuing; provided that, to the extent the Option shall not have been
exercised, it shall terminate and be of no further force and effect upon
the earliest to occur of (i) the Effective Date, (ii) termination of the
Transaction Documents in accordance with the terms of the Reorganization
Agreement before the occurrence of a Purchase Event (other than a


                                  - 3 -
<PAGE>   4







termination resulting from a willful breach by Community, Concord Bank or
Centerpoint Bank of any Specified Covenant contained in the
Reorganization Agreement) or (iii) six months after the termination of
the Transaction Documents if such termination follows the occurrence of a
Purchase Event or is due to a willful material breach by Community,
Concord Bank or Centerpoint Bank of any Specified Covenant contained in
the Reorganization Agreement; and provided further that any such exercise
shall be subject to compliance with applicable provisions of law.

            (b)   If more than one of the transactions giving rise to a
Purchase Event is undertaken or effected, then all such transactions
shall give rise only to one Purchase Event, which Purchase Event shall be
deemed continuing for all purposes hereunder until all such transactions
are abandoned.

            (c)   In the event CFX wishes to exercise the Option, it
shall send to Community a written notice (the date of which being herein
referred to as the "Notice Date") specifying (i) the total number of
shares it will purchase pursuant to such exercise, and (ii) a place and
date not earlier than three business days nor later than 30 business days
from the Notice Date for the closing of such purchase (the "Closing
Date"); provided that, if prior notification to or approval of any
federal or state regulatory agency is required in connection with such
purchase, CFX shall promptly file the required notice or application for
approval and shall expeditiously process the same and the period of time
that otherwise would run pursuant to this sentence shall run instead from
the date on which any required notification period has expired or been
terminated or such approval has been obtained and any requisite waiting
period shall have passed.

      4.    Payment and Delivery of Certificates.

            (a)  At the closing referred to in Section 3 hereof, CFX
shall pay to Community the aggregate purchase price for the shares of
Community Common Stock purchased pursuant to the exercise of the Option
in immediately available funds by a wire transfer to a bank account
designated by Community.

            (b)  At such closing, simultaneously with the delivery of
cash as provided in subsection (a), Community shall deliver to CFX a
certificate or certificates representing the number of shares of
Community Common Stock purchased by CFX, and CFX shall deliver to
Community a letter agreeing that CFX will not offer to sell, pledge or
otherwise dispose of such shares in violation of applicable law or the
provisions of this Option Agreement.

            (c)  Certificates for Community Common Stock delivered at a
closing hereunder may be endorsed with a restrictive legend which shall
read substantially as follows:



                                  - 4 -
<PAGE>   5







      "The transfer of the shares represented by this certificate is
      subject to certain provisions of an agreement between the
      registered holder hereof and Community Bankshares, Inc. and to
      resale restrictions arising under the Securities Act of 1933, as
      amended, a copy of which agreement is on file at the principal
      office of Community Bankshares, Inc.  A copy of such agreement will
      be provided to the holder hereof without charge upon receipt by
      Community Bankshares, Inc. of a written request."

It is understood and agreed that the above legend shall be removed by
delivery of substitute certificate(s) without such legend if CFX shall
have delivered to Community a copy of a letter from the staff of the SEC,
or an opinion of counsel, in form and substance satisfactory to
Community, to the effect that such legend is not required for purposes of
the Securities Act and any applicable state securities laws and this
Option Agreement.

      5.    Representations.  Community hereby represents, warrants and
covenants to CFX as follows:

            (a)  Community shall at all times maintain sufficient
authorized but unissued shares of Community Common Stock so that the
Option may be exercised without authorization of additional shares of
Community Common Stock.

            (b)  The shares to be issued upon due exercise, in whole or
in part, of the Option, when paid for as provided herein, will be duly
authorized, validly issued, fully paid and nonassessable.

      6.    Adjustment Upon Changes in Capitalization.  In the event of
any change in Community Common Stock by reason of stock dividends,
split-ups, recapitalizations, combinations, exchanges of shares or the
like, the type and number of shares subject to the Option, and the
purchase price per share, as the case may be, shall be adjusted
appropriately.  In the event that any additional shares of Community
Common Stock are issued or otherwise become outstanding after the date of
this Option Agreement (other than pursuant to this Option Agreement), the
number of shares of Community Common Stock subject to the Option shall be
adjusted so that, after such issuance, it equals 19.99 percent of the
number of shares of Community Common Stock then issued and outstanding
without giving effect to any shares subject or issued pursuant to the
Option.  Nothing contained in this Section 6 shall be deemed to authorize
Community to breach any provision of the Transaction Documents.

      7.    Registration Rights.  Community shall, if requested by CFX,
as expeditiously as possible file a registration statement on a form of
general use and available for use by Community under the Securities Act
if necessary in order to permit or assist the sale or other disposition
of the shares of Community Common Stock that have been acquired upon
exercise of the Option in accordance with the intended method of sale or


                                  - 5 -
<PAGE>   6







other disposition requested by CFX.  CFX shall provide all information
reasonably requested by Community for inclusion in any registration
statement to be filed hereunder.  Community will use its best efforts to
cause such registration statement first to become effective and then to
remain effective for such period not in excess of 270 days from the day
such registration statement first becomes effective as may be reasonably
necessary to effect such sales or other dispositions.  The obligations of
Community hereunder to file a registration statement and to maintain its
effectiveness may be suspended for one or more periods of time not
exceeding 60 days in the aggregate if the Board of Directors of Community
shall have determined that the filing of such registration statement or
the maintenance of its effectiveness would require disclosure of non-
public information that would materially and adversely affect Community.
The first registration statement prepared under this Section 7 shall be
at Community's expense except for underwriting commissions and the fees
and disbursements of CFX's counsel attributable to the offering of
Community Common Stock by CFX.  The preparation of a second registration
statement may be requested and effected hereunder at CFX's sole expense.
In no event shall Community be required to effect more than two
registrations hereunder.  The filing of any registration statement
hereunder may be delayed for such period of time as may reasonably be
required to facilitate any public distribution by Community of Community
Common Stock.  If requested by CFX in connection with any registration,
Community will become a party to any underwriting agreement relating to
the sale of such shares, but only to the extent of obligating itself in
respect of representations, warranties, indemnities and other agreements
customarily included in such underwriting agreements for parties
similarly situated.  In any such transaction Community and CFX will also
agree to indemnify each other on customary terms with respect to any
information provided by such party.

      8.    Repurchase.

            (a)   Subject to the giving of any notices and the receipt of
any required approvals, at the request of CFX at any time commencing upon
the occurrence of a Repurchase Event and ending nine months thereafter
(the "Repurchase Period"), Community shall repurchase the Option (but not
later than the termination of the Option pursuant to Section 3(a) hereof)
from CFX together with any shares of Community Common Stock purchased by
CFX pursuant thereto with respect to which CFX then has beneficial
ownership, at a price (per share, the "Per Share Repurchase Price") equal
to the sum of:

                  (1)   the exercise price paid by CFX for any shares of
Community Common Stock acquired pursuant to the Option;

                  (2)   the difference between (A) the "market/tender
offer" price for shares of Community Common Stock (defined as the higher
of (x) the highest price per share at which a tender or exchange offer
has been made or (y) the highest reported sale price for shares of


                                  - 6 -
<PAGE>   7







Community Common Stock within that portion of the Repurchase Period
preceding the date CFX gives notice of the required repurchase under this
Section 8) and (B) the exercise price as determined pursuant to Section 2
hereof (subject to adjustment as provided in Section 6) multiplied by the
number of shares of Community Common Stock with respect to which the
Option has not been exercised, but only if the market/tender offer price
is greater than such exercise price;

                  (3)   the difference between the market/tender offer
price (as defined in Section 8(a)(2) hereof) and the exercise price paid
by CFX for any shares of Community Common Stock purchased pursuant to the
exercise of the Option, multiplied by the number of shares so purchased,
but only if the market/tender offer price is greater than such exercise
price; and

                  (4)   CFX's out-of-pocket expenses incurred in
connection with the transactions contemplated by the Transaction
Documents, including without limitation legal, accounting and investment
banking fees.

            (b)   In the event CFX exercises its rights under this
Section 8, Community shall, within thirty business days thereafter, pay
the required amount to CFX in immediately available funds and CFX shall
surrender to Community the Option and the certificates evidencing the
shares of Community Common Stock purchased thereunder and CFX shall
warrant that it owns such shares and that the same are then free and
clear of all liens, charges, claims, restrictions and encumbrances;
provided that, if prior notification to any federal or state regulatory
agency is required in connection with such purchase, Community shall
promptly file the required notice or application for approval and shall
expeditiously process the same and the period of time that otherwise
would run pursuant to this sentence shall run instead from the date on
which any required notification period has expired or been terminated or
such approval has been obtained and any requisite waiting period shall
have passed.

      9.    Severability.  If any term, provision, covenant or
restriction contained in this Option Agreement is held by a court or a
federal or state regulatory agency of competent jurisdiction to be
invalid, void or unenforceable, the remainder of the terms, provisions
and covenants and restrictions contained in this Option Agreement shall
remain in full force and effect, and shall in no way be affected,
impaired or invalidated.  If for any reason such court or regulatory
agency determines that the Option will not permit the holder to acquire
or Community to repurchase the full number of shares of Community Common
Stock provided in Section 2 hereof (as adjusted pursuant to Section 6
hereof), it is the express intention of Community to allow the holder to
acquire or to require Community to repurchase such lesser number of
shares as may be permissible, without any amendment or modification
hereof.


                                  - 7 -
<PAGE>   8








      10.   Miscellaneous.

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

            (b)   Entire Agreement.  Except as otherwise expressly
provided herein, this Option Agreement and the Transaction Documents
contain the entire agreement between the parties with respect to the
transactions contemplated hereunder and supersedes all prior arrangements
or understandings with respect thereto, written or oral.  The terms and
conditions of this Option Agreement shall inure to the benefit of and be
binding upon the parties hereto and their respective successors and
assigns.  Nothing in this Option Agreement, expressed or implied, is
intended to confer upon any party, other than the parties hereto, and
their respective successors and assigns, any rights, remedies,
obligations or liabilities under or by reason of this Option Agreement,
except as expressly provided herein.

            (c)   Assignment.  Other than as provided in Sections 7 and 8
hereof, neither of the parties hereto may assign any of its rights or
obligations under this Option Agreement or the Option created hereunder
to any other person, without the express written consent of the other
party.

            (d)   Notices.  All notices or other communications which are
required or permitted hereunder shall be in writing and sufficient if
delivered personally or sent by overnight express or by registered or
certified mail, postage prepaid, addressed as provided in the
Reorganization Agreement.  A party may change its address for notice
purposes by written notice to the other party hereto.

            (e)   Counterparts.  This Option Agreement may be executed in
any number of counterparts, and each such counterpart shall be deemed to
be an original instrument, but all such counterparts together shall
constitute but one agreement.

            (f)  Specific Performance.  The parties agree that damages
would be an inadequate remedy for a breach of the provisions of this
Option Agreement by either party hereto and that this Option Agreement
may be enforced by either party hereto through injunctive or other
equitable relief.

            (g)   Governing Law.  This Option Agreement shall be governed
by and construed in accordance with the laws of New Hampshire applicable
to agreements made and entirely to be performed within such state and
such federal laws as may be applicable.


                                  - 8 -
<PAGE>   9








      IN WITNESS WHEREOF, each of the parties hereto has executed this
Option Agreement as of the day and year first written above.

                        CFX CORPORATION



                        By:
                             -------------------------------------
                             Peter J. Baxter,
                             President and Chief Executive Officer



                        COMMUNITY BANKSHARES, INC.



                        By:
                             -------------------------------------
                             Douglas Crichfield
                             President and Chief Executive Officer































                                  - 9 -