<PAGE>   1



                                                                     EXHIBIT 4.1

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



                                 MASSBANK CORP.



                                       and



                                BANKBOSTON, N.A.


                                 as Rights Agent





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





                          Shareholder Rights Agreement

                          Dated as of January 18, 2000







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                                TABLE OF CONTENTS
                                -----------------

Section                                                                     Page

1.  CERTAIN DEFINITIONS........................................................2

2.  APPOINTMENT OF RIGHTS AGENT................................................7

3.  ISSUE OF RIGHT CERTIFICATES................................................8

4.  FORM OF RIGHT CERTIFICATES................................................10

5.  COUNTERSIGNATURE AND REGISTRATION.........................................11

6.  TRANSFER, SPLIT UP, COMBINATION AND EXCHANGE OF RIGHT CERTIFICATES;
      MUTILATED, DESTROYED, LOST OR STOLEN RIGHT CERTIFICATES.................11

7.  EXERCISE OF RIGHTS; EXERCISE PRICE; EXPIRATION DATE OF RIGHTS.............12

8.  CANCELLATION AND DESTRUCTION OF RIGHT CERTIFICATES........................14

9.  RESERVATION AND AVAILABILITY OF PREFERRED STOCK...........................15

10. PREFERRED STOCK RECORD DATE...............................................16

11. ADJUSTMENT OF EXERCISE PRICE, NUMBER AND KIND OF SHARES OR NUMBER
      OF RIGHTS...............................................................16

12. CERTIFICATE OF ADJUSTED EXERCISE PRICE OR NUMBER OF SHARES................25

13. CONSOLIDATION, MERGER OR SALE OR TRANSFER OF ASSETS OR EARNING POWER......25

14. FRACTIONAL RIGHTS AND FRACTIONAL SHARES...................................27

15. RIGHTS OF ACTION..........................................................28

16. AGREEMENT OF RIGHT HOLDERS................................................28

17. RIGHT CERTIFICATE HOLDER NOT DEEMED A SHAREHOLDER.........................29

18. CONCERNING THE RIGHTS AGENT...............................................29

19. MERGER OR CONSOLIDATION OR CHANGE OF NAME OF RIGHTS AGENT.................30

20. DUTIES OF RIGHTS AGENT....................................................31

                                      (iii)

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21. CHANGE OF RIGHTS AGENT....................................................33

22. ISSUANCE OF NEW RIGHT CERTIFICATES........................................34

23. REDEMPTION................................................................34

24. EXCHANGE..................................................................35

25. NOTICE OF CERTAIN EVENTS..................................................37

26. NOTICES...................................................................38

27. SUPPLEMENTS AND AMENDMENTS................................................39

28. SUCCESSORS................................................................39

29. DETERMINATIONS AND ACTIONS BY THE BOARD OF DIRECTORS......................39

30. BENEFITS OF THIS AGREEMENT................................................40

31. SEVERABILITY..............................................................40

32. GOVERNING LAW.............................................................40

33. COUNTERPARTS..............................................................40

34. DESCRIPTIVE HEADINGS......................................................40

Exhibit A -- Certificate of Designations of
        Series B Junior Participating
        Cumulative Preferred Stock

Exhibit B -- Form of Right Certificate



                                      (iv)

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                          SHAREHOLDER RIGHTS AGREEMENT
                          ----------------------------


         Agreement, dated as of January 18, 2000, between MASSBANK Corp., a
Delaware corporation (the "Company"), and BankBoston, N.A., a national banking
association (the "Rights Agent").


                               W I T N E S S E T H
                               - - - - - - - - - -

         WHEREAS, the Board of Directors of the Company desires to provide
shareholders of the Company with the opportunity to benefit from the long-term
prospects and value of the Company and to ensure that shareholders of the
Company receive fair and equal treatment in the event of any proposed takeover
of the Company; and

         WHEREAS, on January 16, 1990 the Board of Directors of the Company
authorized the Shareholder Rights Agreement dated as of January 16, 1990 between
the Company and The First National Bank of Boston (as predecessor to BankBoston,
N.A.), as Rights Agent (the "1990 Rights Agreement"), declared a dividend
distribution of one Right (as such term is defined in the 1990 Rights Agreement)
for each outstanding share of Common Stock, par value $1.00 per share, of the
Company (the "Common Stock") outstanding as of the close of business on January
29, 1990 (the "1990 Record Date"), and authorized the issuance of one Right for
each share of Common Stock of the Company issued between the 1990 Record Date
and the earlier of the Distribution Date or the Expiration Date (as such terms
are defined in the 1990 Rights Agreement), each Right initially representing the
right to purchase one one-hundredth of a share of Series A Junior Participating
Cumulative Preferred Stock of the Company upon the terms and subject to the
conditions set forth in the 1990 Rights Agreement; and

         WHEREAS, on January 18, 2000, the Board of Directors of the Company
determined it desirable and in the best interests of the Company and its
shareholders for the Company to extend the benefits afforded by the 1990 Rights
Agreement and to implement such extension by executing this Agreement; and

         WHEREAS, on January 18, 2000, the Board of Directors of the Company
authorized and declared a dividend distribution of one Right (as such term is
hereinafter defined) for each outstanding share of Common Stock of the Company
outstanding as of January 19, 2000 (the "Record Date"), and authorized the
issuance of one Right for each share of Common Stock of the Company issued
(whether or not originally issued or sold from the Company's treasury, except in
the case of treasury shares having associated Rights) between the Record Date
and the earlier of the Distribution Date or the Expiration Date (as such terms
are hereinafter defined), each Right initially representing the right to
purchase one one-thousandth of a share of Series B Junior Participating
Cumulative Preferred Stock of the Company having the rights, powers and
preferences set forth on EXHIBIT A attached hereto, upon the terms and subject
to the conditions hereinafter set forth (the "Rights"); and



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         WHEREAS, the Company desires to appoint the Rights Agent to act as
rights agent hereunder, in accordance with the terms and conditions hereof.

         NOW, THEREFORE, in consideration of the premises and the mutual
agreements herein set forth, the parties hereby agree as follows:

         Section 1. CERTAIN DEFINITIONS. For purposes of this Agreement, the
following terms have the meanings indicated:

                  (a) "ACQUIRING PERSON" shall mean any Person (as such term is
hereinafter defined) who or which, together with all Affiliates (as such term is
hereinafter defined) and Associates (as such term is hereinafter defined) of
such Person, shall be the Beneficial Owner (as such term is hereinafter defined)
of 11% or more of the shares of Common Stock of the Company then outstanding,
but shall not include (i) the Company, (ii) any Subsidiary (as such term is
hereinafter defined) of the Company, (iii) any employee benefit plan or
compensation arrangement of the Company or any Subsidiary of the Company or (iv)
any Person holding shares of Common Stock of the Company organized, appointed or
established by the Company or any Subsidiary of the Company for or pursuant to
the terms of any such employee benefit plan or compensation arrangement (the
Persons described in clauses (i) through (iv) above are referred to herein as
"Exempt Persons"); PROVIDED, HOWEVER, that the term "Acquiring Person" shall not
include any Grandfathered Person, unless such Grandfathered Person at any time
after the Grandfathered Time becomes the Beneficial Owner of more than the
Grandfathered Percentage applicable to such Grandfathered Person.

         Notwithstanding the foregoing, no Person shall become an "Acquiring
Person" as the result of an acquisition by the Company of Common Stock of the
Company which, by reducing the number of shares outstanding, increases the
proportionate number of shares Beneficially Owned by such Person to 11% (or in
the case of a Grandfathered Person, the Grandfathered Percentage applicable to
such Grandfathered Person) or more of the shares of Common Stock of the Company
then outstanding; PROVIDED, HOWEVER, that if a Person shall become the
Beneficial Owner of 11% (or in the case of a Grandfathered Person, the
Grandfathered Percentage applicable to such Grandfathered Person) or more of the
shares of Common Stock of the Company then outstanding by reason of share
purchases by the Company and shall, after such share purchases by the Company,
become the Beneficial Owner of any additional shares (other than pursuant to a
stock split, stock dividend or similar transaction) of Common Stock of the
Company and immediately thereafter be the Beneficial Owner of 11% (or in the
case of a Grandfathered Person, the Grandfathered Percentage applicable to such
Grandfathered Person) or more of the shares of Common Stock of the Company then
outstanding, then such Person shall be deemed to be an "Acquiring Person."

         In addition, notwithstanding the foregoing, a Person shall not be an
"Acquiring Person" if the Board of Directors of the Company determines that a
Person who would otherwise be an "Acquiring Person," has become such without
intending to become an "Acquiring Person," and such Person divests as promptly
as practicable (or within such period of time as the Board

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of Directors of the Company determines is reasonable) a sufficient number of
shares of Common Stock of the Company so that such Person would no longer be an
"Acquiring Person," as defined pursuant to the foregoing provisions of this
Section 1(a).

                  (b) "ADJUSTMENT SHARES" shall have the meaning set forth in
Section 11(a)(ii) hereof.

                  (c) "AFFILIATE" and "ASSOCIATE" shall have the respective
meanings ascribed to such terms in Rule 12b-2 of the General Rules and
Regulations (the "Rules") under the Securities Exchange Act of 1934, as amended
(the "Exchange Act"), as in effect on the date of this Agreement; PROVIDED,
HOWEVER, that no Person who is a director or officer of the Company shall be
deemed an Affiliate or an Associate of any other director or officer of the
Company solely as a result of his or her position as director or officer of the
Company.

                  (d) A Person shall be deemed the "BENEFICIAL OWNER" of, and
shall be deemed to "BENEFICIALLY OWN" and have "BENEFICIAL OWNERSHIP" of, any
securities:

                           (i) which such Person or any of such Person's
         Affiliates or Associates, directly or indirectly, Beneficially Owns (as
         determined pursuant to Rule 13d-3 of the Rules under the Exchange Act,
         as in effect on the date of this Agreement);

                           (ii) which such Person or any of such Person's
         Affiliates or Associates, directly or indirectly, has:

                                    (A) the right to acquire (whether or not
                  such right is exercisable immediately or only after the
                  passage of time or upon the satisfaction of any conditions or
                  both) pursuant to any agreement, arrangement or understanding
                  (whether or not in writing) (other than customary agreements
                  with and between underwriters and selling group members with
                  respect to a bona fide public offering of securities) or upon
                  the exercise of conversion rights, exchange rights, rights
                  (other than the Rights), warrants or options, or otherwise;
                  PROVIDED, HOWEVER, that a Person shall not be deemed the
                  "Beneficial Owner" of, or to "Beneficially Own" or have
                  "Beneficial Ownership" of, (1) securities tendered pursuant to
                  a tender or exchange offer made by or on behalf of such Person
                  or any of such Person's Affiliates or Associates until such
                  tendered securities are accepted for purchase or exchange; (2)
                  securities issuable upon exercise of these Rights at any time
                  prior to the occurrence of a Triggering Event; or (3)
                  securities issuable upon exercise of Rights from and after the
                  occurrence of a Triggering Event, which Rights were acquired
                  by such Person or any of such Person's Affiliates or
                  Associates prior to the Distribution Date or pursuant to
                  Sections 3(a), 11(i) or 22 hereof; or

                                    (B) the right to vote pursuant to any
                  agreement, arrangement or understanding (whether or not in
                  writing); PROVIDED, HOWEVER, that a Person shall not be deemed
                  the "Beneficial Owner" of, or to "Beneficially Own" or

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                  have "Beneficial Ownership" of, any security under this clause
                  (B) if the agreement, arrangement or understanding to vote
                  such security (1) arises solely from a revocable proxy given
                  in response to a public proxy or consent solicitation made
                  pursuant to, and in accordance with, the Rules of the Exchange
                  Act and (2) is not also then reportable by such Person on
                  Schedule 13D under the Exchange Act (or any comparable or
                  successor report); or

                                    (C) the right to dispose of pursuant to any
                  agreement, arrangement or understanding (whether or not in
                  writing) (other than customary arrangements with and between
                  underwriters and selling group members with respect to a bona
                  fide public offering of securities); or

                           (iii) which are Beneficially Owned, directly or
         indirectly, by any other Person (or any Affiliate or Associate thereof)
         with which such Person or any of such Person's Affiliates or Associates
         has any agreement, arrangement or understanding (whether or not in
         writing) (other than customary agreements with and between underwriters
         and selling group members with respect to a bona fide public offering
         of securities) for the purpose of acquiring, holding, voting (except
         pursuant to a revocable proxy as described in clause (B) of Section
         1(d)(ii) hereof) or disposing of any securities of the Company;

PROVIDED, HOWEVER, that (1) no Person engaged in business as an underwriter of
securities shall be deemed the Beneficial Owner of any securities acquired
through such Person's participation as an underwriter in good faith in a firm
commitment underwriting until the expiration of forty (40) days after the date
of such acquisition, and (2) no Person who is a director or an officer of the
Company shall be deemed, as a result of his or her position as director or
officer of the Company, the Beneficial Owner of any securities of the Company
that are Beneficially Owned by any other director or officer of the Company.

                  For all purposes of this Agreement, the phrase "then
outstanding," when used with reference to the percentage of the then outstanding
shares of Common Stock of the Company Beneficially Owned by a Person, shall mean
the number of securities then issued and outstanding together with the number of
such securities not then actually issued and outstanding which such Person would
be deemed to Beneficially Own hereunder.

                  (e) "BUSINESS DAY" shall mean any day other than a Saturday,
Sunday, or a day on which banking institutions in the State of New York are
authorized or obligated by law or executive order to close.

                  (f) "CERTIFICATE OF INCORPORATION" when used in reference to
the Company shall mean the Restated Certificate of Incorporation, as amended, of
the Company.

                  (g) "CLOSE OF BUSINESS" on any given date shall mean 5:00
P.M., New York, New York time, on such date; PROVIDED, HOWEVER, that if such
date is not a Business

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Day it shall mean 5:00 P.M., New York, New York time, on the next succeeding
Business Day.
                  (h) "COMMON STOCK" when used in reference to the Company shall
mean the common stock, par value $1.00 per share, of the Company or any other
shares of capital stock of the Company into which such stock shall be
reclassified or changed. "Common Stock" when used with reference to any Person
other than the Company organized in corporate form shall mean (i) the capital
stock or other equity interest of such Person with the greatest voting power,
(ii) the equity securities or other equity interest having power to control or
direct the management of such Person or (iii) if such Person is a Subsidiary of
another Person, the Person or Persons which ultimately control such
first-mentioned Person and which have issued any such outstanding capital stock,
equity securities or equity interest. "Common Stock" when used with reference to
any Person not organized in corporate form shall mean units of beneficial
interest which (x) shall represent the right to participate generally in the
profits and losses of such Person (including without limitation any flow-through
tax benefits resulting from an ownership interest in such Person) and (y) shall
be entitled to exercise the greatest voting power of such Person or, in the case
of a limited partnership, shall have the power to remove or otherwise replace
the general partner or partners.

                  (i) "CURRENT VALUE" shall have the meaning set forth in
Section 11(a)(iii) hereof.

                  (j) "DEPOSITARY AGENT" shall have the meaning set forth in
Section 7(c) hereof.

                  (k) "DISTRIBUTION DATE" shall have the meaning defined in
Section 3(a) hereof.

                  (l) "EXEMPT PERSON" shall have the meaning set forth in the
definition of "Acquiring Person."

                  (m) "EXERCISE PRICE" shall have the meaning defined in Section
4(a) hereof.

                  (n) "EXPIRATION DATE" and "FINAL EXPIRATION DATE" shall have
the meanings set forth in Section 7(a) hereof.

                  (o) "FAIR MARKET VALUE" of any securities or other property
shall be as determined in accordance with Section 11(d) hereof.

                  (p) "GRANDFATHERED PERCENTAGE" shall mean with respect to any
Grandfathered Person, the percentage of the outstanding shares of Common Stock
of the Company that such Grandfathered Person, together with all Affiliates and
Associates of such Grandfathered Person, Beneficially Owns as of the
Grandfathered Time plus an additional 1/2%. In the event any Grandfathered
Person shall sell, transfer, or otherwise dispose of any outstanding shares of
Common Stock after the Grandfathered Time, the Grandfathered Percentage shall,
subsequent to such sale, transfer or disposition, mean, with respect to such
Grandfathered Person, the lesser of (i) the Grandfathered Percentage as in
effect immediately prior to such sale, transfer or disposition or (ii) the
percentage of outstanding shares of

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Common Stock that such Grandfathered Person Beneficially Owns immediately
following such sale, transfer or disposition plus an additional 1/2%.

                  (q) "GRANDFATHERED PERSON" shall mean any Person who or which,
together with all Affiliates and Associates of such Person, is, as of the
Grandfathered Time, the Beneficial Owner of 11% or more of the shares of Common
Stock of the Company then outstanding. Notwithstanding anything to the contrary
provided in this Agreement, any Grandfathered Person who after the Grandfathered
Time becomes the Beneficial Owner of less than 11% of the shares of Common Stock
of the Company then outstanding shall cease to be a Grandfathered Person.

                  (r) "GRANDFATHERED TIME" shall mean 11:30 a.m., New York, New
York time, on Wednesday, January 19, 2000.

                  (s) "GROUP" shall have the meaning set forth in clause (b) of
the definition of "Person."

                  (t) "NASDAQ" shall have the meaning set forth in Section 9(b)
hereof.

                  (u) "PERSON" shall mean (a) an individual, a corporation, a
partnership, an association, a joint stock company, a trust, a business trust, a
government or political subdivision, any unincorporated organization, or any
other association or entity, and (b) a "group" as that term is used for purposes
of Section 13(d)(3) of the Securities Exchange Act of 1934, as amended.

                  (v) "PREFERRED STOCK" shall mean shares of Series B Junior
Participating Cumulative Preferred Stock, par value $1.00 per share, of the
Company having the rights and preferences set forth in EXHIBIT A attached
hereto.

                  (w) "PREFERRED STOCK EQUIVALENTS" shall have the meaning set
forth in Section 11(b) hereof.

                  (x) "REDEMPTION PRICE" shall have the meaning defined in
Section 23 hereof.

                  (y) "REGISTERED COMMON STOCK" shall have the meaning set forth
in Section 13(b) hereof.

                  (z) "RIGHT CERTIFICATE" shall have the meaning set forth in
Section 3(a) hereof.

                  (aa) "SECTION 11(a)(ii) EVENT" shall have the meaning set
forth in Section 11(a)(ii) hereof.

                  (bb) "SECTION 11(a)(ii) TRIGGER DATE" shall have the meaning
set forth in Section 11(a)(iii) hereof.


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                  (cc) "SECTION 13 EVENT" shall mean any event described in
clauses (x), (y) or (z) of Section 13(a) hereof.

                  (dd) "SECTION 24(a)(i) EXCHANGE RATIO" shall have the meaning
set forth in Section 24(a)(i) hereof.

                  (ee) "SECTION 24(a)(i) EXCHANGE RATIO" shall have the meaning
set forth in Section 24(a)(ii) hereof.

                  (ff) "SPREAD" shall have the meaning set forth in Section
11(a)(iii) hereof.

                  (gg) "STOCK ACQUISITION DATE" shall mean the date of the first
public announcement (which for purposes of this definition shall include,
without limitation, the issuance of a press release or the filing of a
publicly-available report or other document with the Securities and Exchange
Commission or any other governmental agency) by the Company or an Acquiring
Person that an Acquiring Person has become such.

                  (hh) "SUBSIDIARY" shall mean, with reference to any Person,
any corporation or other entity of which securities or other ownership interests
having ordinary voting power sufficient, in the absence of contingencies, to
elect a majority of the board of directors or other persons performing similar
functions of such corporation or other entity are at the time directly or
indirectly Beneficially Owned or otherwise controlled by such Person either
alone or together with one or more Affiliates of such Person.

                  (ii) "SUBSTITUTION PERIOD" shall have the meaning set forth in
Section 11(a)(iii) hereof.

                  (jj) "TRIGGERING EVENT" shall mean any Section 11(a)(ii) Event
or any Section 13 Event.

         Section 2. APPOINTMENT OF RIGHTS AGENT. The Company hereby appoints the
Rights Agent to act as agent for the Company and the holders of the Rights (who,
in accordance with Section 3 hereof, shall prior to the Distribution Date (as
hereinafter defined in Section 3(a)) also be the holders of the Common Stock of
the Company) in accordance with the terms and conditions hereof, and the Rights
Agent hereby accepts such appointment. The Company may from time to time appoint
such Co-Rights Agents as it may deem necessary or desirable. In the event the
Company appoints one or more Co-Rights Agents, the respective duties of the
Rights Agent and any Co-Rights Agents shall be as the Company shall determine.
The Company shall give ten (10) days' prior written notice to the Rights Agent
of the appointment of one or more Co-Rights Agents and the respective duties of
the Rights Agent and any such Co-Rights Agents. The Rights Agent shall have no
duty to supervise, and shall in no event be liable for, the acts or omissions of
any such Co-Rights Agent.


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         Section 3.  ISSUE OF RIGHT CERTIFICATES.

                  (a) From the date hereof until the earlier of (i) the Close of
Business on the tenth calendar day after the Stock Acquisition Date, or (ii) the
Close of Business on the tenth Business Day (or such later calendar day, if any,
as the Board of Directors of the Company may determine in its sole discretion
prior to the time at which any Person becomes an Acquiring Person) after the
date on which a tender or exchange offer by any Person, other than an Exempt
Person, is commenced within the meaning of Rule 14d-2(a) of the Exchange Act, or
any successor rule, or, if earlier, after the first public announcement of the
intention by any Person, other than an Exempt Person, to commence a tender or
exchange offer (whether by means of a pre-commencement communication within the
meaning of Rule 14d-2(b) of the Exchange Act, or any successor rule, or
otherwise) if, in any case, upon consummation thereof, such Person could become
the Beneficial Owner of 11% (or in the case of a Grandfathered Person, the
Grandfathered Percentage applicable to such Grandfathered Person) or more of the
shares of Common Stock of the Company then outstanding (including any such date
which is after the date of this Agreement and prior to the issuance of the
Rights) (the earliest of such dates being herein referred to as the
"Distribution Date"), (x) the Rights will be evidenced (subject to the
provisions of Section 3(b) hereof) by the certificates for the Common Stock of
the Company registered in the names of the holders of the Common Stock of the
Company (which certificates for Common Stock of the Company shall be deemed also
to be certificates for Rights) and not by separate certificates, and (y) the
Rights will be transferable only in connection with the transfer of the
underlying shares of Common Stock of the Company. As soon as practicable after
the Distribution Date, the Rights Agent will, at the Company's expense send, by
first-class, insured, postage prepaid mail, to each record holder of the Common
Stock of the Company as of the Close of Business on the Distribution Date, at
the address of such holder shown on the records of the Company, one or more
certificates, in substantially the form of EXHIBIT B attached hereto (the "Right
Certificates"), evidencing one Right for each share of Common Stock of the
Company so held, subject to adjustment as provided herein. In the event that an
adjustment in the number of Rights per share of Common Stock of the Company has
been made pursuant to Section 11(o) hereof, the Company may make the necessary
and appropriate rounding adjustments (in accordance with Section 14(a) hereof)
at the time of distribution of the Right Certificates, so that Right
Certificates representing only whole numbers of Rights are distributed and cash
is paid in lieu of any fractional Rights. As of and after the Close of Business
on the Distribution Date, the Rights will be evidenced solely by such Right
Certificates.

                  (b) With respect to certificates for the Common Stock of the
Company issued prior to the Close of Business on the Record Date, the Rights
will be evidenced by such certificates for the Common Stock of the Company on or
until the Distribution Date (or the earlier redemption, expiration or
termination of the Rights), and the registered holders of the Common Stock of
the Company also shall be the registered holders of the associated Rights. Until
the Distribution Date (or the earlier redemption, expiration or termination of
the Rights), the transfer of any of the certificates for the Common Stock of the
Company outstanding prior to the date of this Agreement shall also constitute
the transfer of the Rights associated with the

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Common Stock of the Company represented by such certificate.

                  (c) Certificates for the Common Stock of the Company issued
after the Record Date, but prior to the earlier of the Distribution Date or the
redemption, expiration or termination of the Rights, shall be deemed also to be
certificates for Rights, and shall bear a legend, substantially in the form set
forth below:

                  This certificate also evidences and entitles the holder hereof
                  to certain Rights as set forth in a Shareholder Rights
                  Agreement between MASSBANK Corp. and BankBoston, N.A., as
                  Rights Agent, dated as of January 18, 2000, as amended,
                  restated, renewed or extended from time to time (the "Rights
                  Agreement"), the terms of which are hereby incorporated herein
                  by reference and a copy of which is on file at the principal
                  offices of MASSBANK Corp. and the stock transfer
                  administration office of the Rights Agent. Under certain
                  circumstances, as set forth in the Rights Agreement, such
                  Rights will be evidenced by separate certificates and will no
                  longer be evidenced by this certificate. MASSBANK Corp. may
                  redeem the Rights at a redemption price of $0.01 per Right,
                  subject to adjustment, under the terms of the Rights
                  Agreement. MASSBANK Corp. will mail to the holder of this
                  certificate a copy of the Rights Agreement, as in effect on
                  the date of mailing, without charge promptly after receipt of
                  a written request therefor. As set forth in the Rights
                  Agreement, Rights issued to or held by Acquiring Persons or
                  any Affiliates or Associates thereof (as defined in the Rights
                  Agreement), and any subsequent holder of such Rights, become
                  null and void. The Rights shall not be exercisable, and shall
                  be void so long as held, by a holder in any jurisdiction where
                  the requisite qualification, if any, to the issuance to such
                  holder, or the exercise by such holder, of the Rights in such
                  jurisdiction shall not have been obtained or be obtainable.

With respect to such certificates containing the foregoing legend, the Rights
associated with the Common Stock of the Company represented by such certificates
shall be evidenced by such certificates alone until the Distribution Date (or
the earlier redemption, expiration or termination of the Rights), and the
transfer of any of such certificates shall also constitute the transfer of the
Rights associated with the Common Stock of the Company represented by such
certificates. In the event that the Company purchases or acquires any shares of
Common Stock of the Company after the Record Date but prior to the Distribution
Date, any Rights associated with such Common Stock of the Company shall be
deemed canceled and retired so that the Company shall not be entitled to
exercise any Rights associated with the shares of Common Stock of the Company
which are no longer outstanding. The failure to print the foregoing legend on
any such certificate representing Common Stock of the Company or any defect

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<PAGE>   13



therein shall not affect in any manner whatsoever the application or
interpretation of the provisions of Section 7(e) hereof.

         Section 4.  FORM OF RIGHT CERTIFICATES.

                  (a) The Right Certificates (and the forms of election to
purchase shares and of assignment and certificate to be printed on the reverse
thereof) shall each be substantially in the form of EXHIBIT B attached hereto
and may have such marks of identification or designation and such legends,
summaries or endorsements printed thereon as the Company may deem appropriate
and as are not inconsistent with the provisions of this Agreement, or as may be
required to comply with any applicable law, rule or regulation or with any rule
or regulation of any stock exchange on which the Rights may from time to time be
listed, or to conform to customary usage. The Right Certificates shall be in a
machine-printable format and in a form reasonably satisfactory to the Rights
Agent. Subject to the provisions of Section 11 and Section 22 hereof, the Right
Certificates, whenever distributed, shall show the date of countersignature, and
on their face shall entitle the holders thereof to purchase such number of one
one-thousandths of a share of Preferred Stock as shall be set forth therein at
the price set forth therein (the "Exercise Price"), but the number of such
shares and the Exercise Price shall be subject to adjustment as provided herein.

                  (b) Any Right Certificate issued pursuant to Section 3(a) or
Section 22 hereof that represents Rights Beneficially Owned by (i) an Acquiring
Person or any Associate or Affiliate of an Acquiring Person, (ii) a transferee
of an Acquiring Person (or of any Associate or Affiliate of an Acquiring Person)
who becomes a transferee after the Acquiring Person becomes such, or (iii) a
transferee of an Acquiring Person (or of any such Associate or Affiliate) who
becomes a transferee prior to or concurrently with the Acquiring Person becoming
such and receives such Rights pursuant to either (A) a transfer (whether or not
for consideration) from the Acquiring Person to holders of equity interests in
such Acquiring Person or to any Person with whom the Acquiring Person has any
continuing agreement, arrangement or understanding (whether or not in writing)
regarding the transferred Rights, the shares of Common Stock of the Company
associated with such Rights or the Company or (B) a transfer which the Board of
Directors of the Company has determined is part of a plan, arrangement or
understanding which has as a primary purpose or effect the avoidance of Section
7(e) hereof, and any Right Certificate issued pursuant to Section 6, Section 11
or Section 22 upon transfer, exchange, replacement or adjustment of any other
Right Certificate referred to in this sentence, shall have deleted therefrom the
second sentence of the existing legend on such Right Certificate and in
substitution therefor shall contain the following legend:

                  The Rights represented by this Right Certificate are or were
                  Beneficially Owned by a Person who was or became an Acquiring
                  Person or an Affiliate or an Associate of an Acquiring Person
                  (as such terms are defined in the Rights Agreement). This
                  Right Certificate and the Rights represented hereby may become

                                       10

<PAGE>   14



                  null and void under certain circumstances as specified in
                  Section 7(e) of the Rights Agreement.

The Company shall give notice to the Rights Agent promptly after it becomes
aware of the existence and identity of any Acquiring Person or any Associate or
Affiliate thereof. The Company shall instruct the Rights Agent in writing of the
Rights which should be so legended. The failure to print the foregoing legend on
any such Right Certificate or any defect therein shall not affect in any manner
whatsoever the application or interpretation of the provisions of Section 7(e)
hereof.

         Section 5.  COUNTERSIGNATURE AND REGISTRATION.

                  (a) The Right Certificates shall be executed on behalf of the
Company by its Chairman of the Board of Directors, or its President or any Vice
President and by its Treasurer or any Assistant Treasurer, or by its Secretary
or any Assistant Secretary, either manually or by facsimile signature, and shall
have affixed thereto the Company's seal or a facsimile thereof which shall be
attested to by the Secretary or any Assistant Secretary of the Company, either
manually or by facsimile signature. The Right Certificates shall be manually
countersigned by an authorized signatory of the Rights Agent and shall not be
valid for any purpose unless so countersigned, and such countersignature upon
any Right Certificate shall be conclusive evidence, and the only evidence, that
such Right Certificate has been duly countersigned as required hereunder. In
case any officer of the Company who shall have signed any of the Right
Certificates shall cease to be such officer of the Company before
countersignature by the Rights Agent and issuance and delivery by the Company,
such Right Certificates, nevertheless, may be countersigned by an authorized
signatory of the Rights Agent, and issued and delivered by the Company with the
same force and effect as though the person who signed such Right Certificates
had not ceased to be such officer of the Company; and any Right Certificates may
be signed on behalf of the Company by any person who, at the actual date of the
execution of such Right Certificate, shall be a proper officer of the Company to
sign such Right Certificate, although at the date of the execution of this
Rights Agreement any such person was not such an officer.

                  (b) Following the Distribution Date, the Rights Agent will
keep or cause to be kept, at one of its offices designated as the appropriate
place for surrender of Right Certificates upon exercise or transfer, books for
registration and transfer of the Right Certificates issued hereunder. Such books
shall show the names and addresses of the respective holders of the Right
Certificates, the number of Rights evidenced on its face by each of the Right
Certificates and the date of each of the Right Certificates.

         Section 6. TRANSFER, SPLIT UP, COMBINATION AND EXCHANGE OF RIGHT
CERTIFICATES; MUTILATED, DESTROYED, LOST OR STOLEN RIGHT CERTIFICATES.

                  (a) Subject to the provisions of Section 4(b), Section 7(e)
and Section 14 hereof, at any time after the Close of Business on the
Distribution Date, and at or prior to the

                                       11

<PAGE>   15



Close of Business on the Expiration Date, any Right Certificate or Certificates
may be transferred, split up, combined or exchanged for another Right
Certificate or Certificates, entitling the registered holder to purchase a like
number of one one-thousandths of a share of Preferred Stock (or following a
Triggering Event, preferred stock, cash, property, debt securities, Common Stock
of the Company or any combination thereof) as the Right Certificate or
Certificates surrendered then entitled such holder to purchase and at the same
Exercise Price. Any registered holder desiring to transfer, split up, combine or
exchange any Right Certificate shall make such request in writing delivered to
the Rights Agent, and shall surrender the Right Certificate or Certificates to
be transferred, split up, combined or exchanged, with the form of assignment and
certificate duly executed, at the office or offices of the Rights Agent
designated for such purpose. Neither the Rights Agent nor the Company shall be
obligated to take any action whatsoever with respect to the transfer of any such
surrendered Right Certificate until the registered holder shall have completed
and signed the certificate contained in the form of assignment on the reverse
side of such Right Certificate and shall have provided such additional evidence
of the identity of the Beneficial Owner (or former Beneficial Owner) or
Affiliates or Associates thereof as the Company shall reasonably request.
Thereupon the Rights Agent shall, subject to Section 4(b), Section 7(e) and
Section 14 hereof, countersign and deliver to the Person entitled thereto a
Right Certificate or Certificates, as the case may be, as so requested. The
Company may require payment by the registered holder of a Right Certificate, of
a sum sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer, split up, combination or exchange of Right
Certificates.

                  (b) Upon receipt by the Company and the Rights Agent of
evidence reasonably satisfactory to them of the loss, theft, destruction or
mutilation of a Right Certificate, and, in case of loss, theft or destruction,
of indemnity or security satisfactory to them, and reimbursement to the Company
and the Rights Agent of all reasonable expenses incidental thereto, and upon
surrender to the Rights Agent and cancellation of the Right Certificate, if
mutilated, the Company will execute and deliver a new Right Certificate of like
tenor to the Rights Agent for countersignature and delivery to the registered
owner in lieu of the Right Certificate so lost, stolen, destroyed or mutilated.

         Section 7. EXERCISE OF RIGHTS; EXERCISE PRICE; EXPIRATION DATE OF
RIGHTS.

                  (a) Subject to Section 7(e) hereof, the registered holder of
any Right Certificate may exercise the Rights evidenced thereby (except as
otherwise provided herein) in whole or in part at any time after the
Distribution Date upon surrender of the Right Certificate, with the form of
election to purchase and the certificate on the reverse side thereof duly
executed, to the Rights Agent at the office or offices of the Rights Agent
designated for such purpose, together with payment of the aggregate Exercise
Price for the total number of one one-thousandths of a share of Preferred Stock
(or other securities, cash or other assets, as the case may be) as to which such
surrendered Rights are then exercised, at or prior to the earlier of (i) the
Close of Business on the tenth anniversary of the Record Date (the "Final
Expiration Date"), (ii) the time at which the Rights are redeemed as provided in
Section 23 hereof or

                                       12

<PAGE>   16



(iii) the time at which such Rights are exchanged as provided in Section 24
hereof (the earlier of (i), (ii) or (iii) being herein referred to as the
"Expiration Date"). Except as set forth in Section 7(e) hereof and
notwithstanding any other provision of this Agreement, any Person who prior to
the Distribution Date becomes a record holder of shares of Common Stock of the
Company may exercise all of the rights of a registered holder of a Right
Certificate with respect to the Rights associated with such shares of Common
Stock of the Company in accordance with the provisions of this Agreement, as of
the date such Person becomes a record holder of shares of Common Stock of the
Company.

                  (b) The Exercise Price for each one one-thousandth of a share
of Preferred Stock pursuant to the exercise of a Right shall initially be One
Hundred Thirty-Six Dollars ($136.00), shall be subject to adjustment from time
to time as provided in Section 11 and Section 13 hereof and shall be payable in
lawful money of the United States of America in accordance with Section 7(c)
below.

                  (c) As promptly as practicable following the Distribution
Date, the Company shall deposit with a corporation, trust, bank or similar
institution in good standing organized under the laws of the United States or
any State of the United States, which is authorized under such laws to exercise
corporate trust or stock transfer powers and is subject to supervision or
examination by a federal or state authority (such institution is hereinafter
referred to as the "Depositary Agent"), certificates representing the shares of
Preferred Stock that may be acquired upon exercise of the Rights and the Company
shall cause such Depositary Agent to enter into an agreement pursuant to which
the Depositary Agent shall issue receipts representing interests in the shares
of Preferred Stock so deposited. Upon receipt of a Right Certificate
representing exercisable Rights, with the form of election to purchase and the
certificate on the reverse side thereof duly executed, accompanied by payment of
the Exercise Price for the shares to be purchased and an amount equal to any
applicable transfer tax (as determined by the Rights Agent) by certified check
or bank draft payable to the order of the Company or by money order, the Rights
Agent shall, subject to Section 20(k) hereof, thereupon promptly (i) requisition
from the Depositary Agent (or make available, if the Rights Agent is the
Depositary Agent) depositary receipts or certificates for the number of one
one-thousandths of a share of Preferred Stock to be purchased and the Company
hereby irrevocably authorizes the Depositary Agent to comply with all such
requests, (ii) when appropriate, requisition from the Company the amount of
cash, if any, to be paid in lieu of issuance of fractional shares in accordance
with Section 14 hereof, (iii) promptly after receipt of such certificates or
depositary receipts, cause the same to be delivered to or upon the order of the
registered holder of such Right Certificate, registered in such name or names as
may be designated by such holder and (iv) when appropriate, after receipt
promptly deliver such cash to or upon the order of the registered holder of such
Right Certificate. In the event that the Company is obligated to issue other
securities (including Common Stock) of the Company, pay cash or distribute other
property pursuant to Section 11(a) hereof, the Company will make all
arrangements necessary so that such other securities, cash or other property are
available for distribution by the Rights Agent, if and when appropriate. The
payment of the Exercise Price may be made by certified or bank check payable to
the order of the Company, or by money

                                       13

<PAGE>   17



order or wire transfer of immediately available funds to the account of the
Company (provided that notice of such wire transfer shall be given by the holder
of the related Right to the Rights Agent).

                  (d) In case the registered holder of any Right Certificate
shall exercise less than all the Rights evidenced thereby, a new Right
Certificate evidencing Rights equivalent to the Rights remaining unexercised
shall be issued by the Rights Agent and delivered to the registered holder of
such Right Certificate or to his duly authorized assigns, subject to the
provisions of Section 14 hereof.

                  (e) Notwithstanding anything in this Agreement to the
contrary, from and after the first occurrence of a Section 11(a)(ii) Event or
Section 13 Event, any Rights Beneficially Owned by (i) an Acquiring Person or
any Associate or Affiliate of an Acquiring Person, (ii) a transferee of an
Acquiring Person (or of any Associate or Affiliate of an Acquiring Person) who
becomes a transferee after the Acquiring Person becomes such or (iii) a
transferee of an Acquiring Person (or of any Associate or Affiliate of an
Acquiring Person) who becomes a transferee prior to or concurrently with the
Acquiring Person becoming such and receives such Rights pursuant to either (A) a
transfer (whether or not for consideration) from the Acquiring Person to holders
of equity interests in such Acquiring Person or to any Person with whom the
Acquiring Person has any continuing agreement, arrangement or understanding
regarding the transferred Rights, the shares of Common Stock of the Company
associated with such Rights or the Company, or (B) a transfer which the Board of
Directors of the Company has determined is part of a plan, arrangement or
understanding which has as a primary purpose or effect the avoidance of this
Section 7(e), shall be null and void without any further action and no holder of
such Rights shall have any rights whatsoever with respect to such Rights,
whether under any provision of this Agreement or otherwise. The Company shall
use all reasonable efforts to ensure that the provisions of this Section 7(e)
and Section 4(b) hereof are complied with, but shall have no liability to any
holder of Right Certificates or other Person as a result of its failure to make
any determinations with respect to an Acquiring Person or any Affiliates or
Associates of an Acquiring Person or any transferee of any of them hereunder.

                  (f) Notwithstanding anything in this Agreement to the
contrary, neither the Rights Agent nor the Company shall be obligated to
undertake any action with respect to a registered holder of Rights upon the
occurrence of any purported exercise as set forth in this Section 7 unless such
registered holder shall have (i) completed and signed the certificate contained
in the form of election to purchase set forth on the reverse side of the Right
Certificate surrendered for such exercise, and (ii) provided such additional
evidence of the identity of the Beneficial Owner (or former Beneficial Owner) or
Affiliates or Associates thereof as the Company shall reasonably request.

         Section 8. CANCELLATION AND DESTRUCTION OF RIGHT CERTIFICATES. All
Right Certificates surrendered for the purpose of exercise, transfer, split up,
combination or exchange shall, if surrendered to the Company or any of its
agents, be delivered to the Rights Agent for

                                       14

<PAGE>   18



cancellation or in canceled form, or, if surrendered to the Rights Agent, shall
be canceled by it, and no Right Certificates shall be issued in lieu thereof
except as expressly permitted by any of the provisions of this Agreement. The
Company shall deliver to the Rights Agent for cancellation and retirement, and
the Rights Agent shall so cancel and retire, any other Right Certificate
purchased or acquired by the Company otherwise than upon the exercise thereof.
The Rights Agent shall deliver all canceled Right Certificates to the Company.

         Section 9.  RESERVATION AND AVAILABILITY OF PREFERRED STOCK.

                  (a) The Company covenants and agrees that it will cause to be
reserved and kept available out of its authorized and unissued shares of
Preferred Stock or any authorized and issued shares of Preferred Stock held in
its treasury, the number of shares of Preferred Stock that will be sufficient to
permit the exercise in full of all outstanding and exercisable Rights. Upon the
occurrence of any events resulting in an increase in the aggregate number of
shares of Preferred Stock issuable upon exercise of all outstanding Rights in
excess of the number then reserved, the Company shall make appropriate increases
in the number of shares so reserved.

                  (b) The Company shall use its best efforts to cause, from and
after such time as the Rights become exercisable, all shares of Preferred Stock
issued or reserved for issuance to be listed, upon official notice of issuance,
upon the principal national securities exchange, if any, upon which the Common
Stock of the Company is listed or, if the principal market for the Common Stock
of the Company is not on any national securities exchange, to be eligible for
listing on the Nasdaq National Market of The Nasdaq Stock Market, Inc.
("NASDAQ") or any successor thereto or other comparable nationally recognized
securities quotation system.

                  (c) The Company shall use its best efforts to (i) file, as
soon as practicable following the earliest date after the occurrence of a
Section 11(a)(ii) Event on which the consideration to be delivered by the
Company upon exercise of the Rights has been determined in accordance with
Section 11(a)(iii) hereof, or as soon as required by law following the
Distribution Date, as the case may be, a registration statement under the
Securities Act of 1933, as amended (the "Securities Act"), with respect to the
securities purchasable upon exercise of the Rights on an appropriate form, (ii)
cause such registration statement to become effective as soon as practicable
after such filing and (iii) cause such registration statement to remain
effective (with a prospectus that at all times meets the requirements of the
Securities Act) until the earlier of (A) the date as of which the Rights are no
longer exercisable for such securities or (B) the Expiration Date. The Company
will also take such action as may be appropriate under, and which will ensure
compliance with, the securities or "blue sky" laws of the various states in
connection with the exercisability of the Rights. The Company may temporarily
suspend, for a period of time not to exceed ninety (90) days after the date
determined in accordance with the provisions of the first sentence of this
Section 9(c), the exercisability of the Rights in order to prepare and file such
registration statement and permit it to become effective. Upon such suspension,
the Company shall issue a public announcement stating that the exercisability of
the Rights has been temporarily suspended, as well as a public

                                       15

<PAGE>   19



announcement at such time as the suspension is no longer in effect, in each case
with prompt written notice to the Rights Agent. Notwithstanding any such
provision of this Agreement to the contrary, the Rights shall not be exercisable
in any jurisdiction unless the requisite qualification in such jurisdiction
shall have been obtained.

                  (d) The Company covenants and agrees that it will take all
such action as may be necessary to ensure that all shares of Preferred Stock
delivered upon the exercise of the Rights shall, at the time of delivery of the
certificates or depositary receipts for such shares (subject to payment of the
Exercise Price), be duly and validly authorized and issued and fully paid and
nonassessable.

                  (e) The Company further covenants and agrees that it will pay
when due and payable any and all federal and state transfer taxes and charges
which may be payable in respect of the issuance or delivery of the Right
Certificates or of any certificates for shares of Preferred Stock upon the
exercise of Rights. The Company shall not, however, be required to pay any
transfer tax which may be payable in respect of any transfer or delivery of
Right Certificates to a person other than, or in respect of the issuance or
delivery of securities in a name other than that of, the registered holder of
the Right Certificates evidencing Rights surrendered for exercise or to issue or
deliver any certificates for securities in a name other than that of the
registered holder upon the exercise of any Rights until such tax shall have been
paid (any such tax being payable by the holder of such Right Certificate at the
time of surrender) or until it has been established to the Company's
satisfaction that no such tax is due.

         Section 10. PREFERRED STOCK RECORD DATE. Each Person in whose name any
certificate for Preferred Stock (including any fraction of a share of Preferred
Stock) is issued upon the exercise of Rights shall for all purposes be deemed to
have become the holder of record of the shares of Preferred Stock represented
thereby on, and such certificate shall be dated, the date upon which the Right
Certificate evidencing such Rights was duly surrendered and payment of the
Exercise Price (and any applicable transfer taxes) was made; PROVIDED, HOWEVER,
that if the date of such surrender and payment is a date upon which the
Preferred Stock transfer books of the Company are closed, such person shall be
deemed to have become the record holder of such shares on, and such certificate
shall be dated, the next succeeding Business Day on which the Preferred Stock
transfer books of the Company are open; and further PROVIDED, HOWEVER, that if
delivery of shares of Preferred Stock is delayed pursuant to Section 9(c), such
Person shall be deemed to have become the record holder of such shares of
Preferred Stock only when such shares first become deliverable. Prior to the
exercise of the Right evidenced thereby, the holder of a Right Certificate shall
not be entitled to any rights of a shareholder of the Company with respect to
shares for which the Rights shall be exercisable, including, without limitation,
the right to vote, to receive dividends or other distributions or to exercise
any preemptive rights, and shall not be entitled to receive any notice of any
proceedings of the Company, except as provided herein.

         Section 11. ADJUSTMENT OF EXERCISE PRICE, NUMBER AND KIND OF SHARES OR
NUMBER OF RIGHTS. The Exercise Price, the number and kind of shares covered by
each Right and the

                                       16

<PAGE>   20



number of Rights outstanding are subject to adjustment from time to time as
provided in this Section 11.

                  (a) (i) In the event the Company shall at any time after the
         date of this Agreement (A) declare a dividend on the Preferred Stock
         payable in shares of Preferred Stock, (B) subdivide the outstanding
         Preferred Stock, (C) combine the outstanding Preferred Stock into a
         smaller number of shares or (D) issue any shares of its capital stock
         in a reclassification of the Preferred Stock (including any such
         reclassification in connection with a consolidation or merger in which
         the Company is the continuing or surviving corporation), except as
         otherwise provided in this Section 11(a) and Section 7(e) hereof, the
         Exercise Price in effect at the time of the record date for such
         dividend or of the effective date of such subdivision, combination or
         reclassification, and the number and kind of shares of capital stock
         issuable on such date, shall be proportionately adjusted so that the
         holder of any Right exercised after such time shall be entitled to
         receive the aggregate number and kind of shares of capital stock which,
         if such Right had been exercised immediately prior to such date and at
         a time when the Preferred Stock transfer books of the Company were
         open, such holder would have owned upon such exercise and been entitled
         to receive by virtue of such dividend, subdivision, combination or
         reclassification; PROVIDED, HOWEVER, that in no event shall the
         consideration to be paid upon the exercise of a Right be less than the
         aggregate par value of the shares of capital stock of the Company
         issuable upon exercise of a Right. If an event occurs which would
         require an adjustment under both Section 11(a)(i) and Section 11(a)(ii)
         hereof, the adjustment provided for in this Section 11(a)(i) shall be
         in addition to, and shall be made prior to, any adjustment required
         pursuant to Section 11(a)(ii) hereof.

                  (ii) Subject to the provisions of Section 24 hereof, in the
         event any Person, alone or together with its Affiliates and Associates,
         shall become an Acquiring Person, then, promptly following any such
         occurrence (a "Section 11(a)(ii) Event"), proper provision shall be
         made so that each holder of a Right, except as provided in Section 7(e)
         hereof, shall thereafter have a right to receive, upon exercise thereof
         at the then current Exercise Price in accordance with the terms of this
         Agreement, such number of shares of Preferred Stock of the Company as
         shall equal the result obtained by (x) multiplying the then current
         Exercise Price by the then number of one one-thousandths of a share of
         Preferred Stock for which a Right was exercisable immediately prior to
         the first occurrence of a Section 11(a)(ii) Event, whether or not such
         Right was then exercisable, and dividing that product by (y) 50% of the
         Fair Market Value per one one-thousandth of a share of the Preferred
         Stock (determined pursuant to Section 11(d)) on the date of the
         occurrence of a Section 11(a)(ii) Event (such number of shares being
         referred to as the "Adjustment Shares").

                  (iii) In lieu of issuing any shares of Preferred Stock in
         accordance with Section 11(a)(ii) hereof, the Company, acting by or
         pursuant to a resolution of the Board of Directors of the Company, may,
         and in the event that the number of shares of

                                       17

<PAGE>   21



         Preferred Stock which are authorized by the Company's Certificate of
         Incorporation but not outstanding or reserved for issuance for purposes
         other than upon exercise of the Rights is not sufficient to permit the
         exercise in full of the Rights in accordance with the foregoing
         subparagraph (ii) of this Section 11(a), the Company, acting by or
         pursuant to a resolution of the Board of Directors of the Company,
         shall: (A) determine the excess of (X) the Fair Market Value of the
         Adjustment Shares issuable upon the exercise of a Right (the "Current
         Value") over (Y) the Exercise Price attributable to each Right (such
         excess being referred to as the "Spread") and (B) with respect to all
         or a portion of each Right (subject to Section 7(e) hereof), make
         adequate provision to substitute for the Adjustment Shares, upon
         payment of the applicable Exercise Price, (1) Common Stock of the
         Company, (2) cash, (3) a reduction in the Exercise Price, (4) Preferred
         Stock Equivalents which the Board of Directors of the Company has
         deemed to have the same value as shares of Common Stock of the Company,
         (5) debt securities of the Company, (6) other assets or securities of
         the Company or (7) any combination of the foregoing which, when added
         to any shares of Preferred Stock issued upon such exercise, has an
         aggregate value equal to the Current Value, where such aggregate value
         has been determined by the Board of Directors of the Company based upon
         the advice of a nationally recognized investment banking firm selected
         by the Board of Directors of the Company; PROVIDED, HOWEVER, that if
         the Company shall not have made adequate provision to deliver value
         pursuant to clause (B) above within thirty (30) days following the
         later of (x) the first occurrence of a Section 11(a)(ii) Event and (y)
         the date on which the Company's right of redemption pursuant to Section
         23(a) expires (the later of (x) and (y) being referred to herein as the
         "Section 11(a)(ii) Trigger Date"), then the Company shall be obligated
         to deliver, upon the surrender for exercise of a Right and without
         requiring payment of the Exercise Price, shares of Preferred Stock (to
         the extent available) and then, if necessary, cash, which shares and/or
         cash have an aggregate value equal to the Spread. If the Board of
         Directors of the Company shall determine in good faith that it is
         likely that sufficient additional shares of Preferred Stock could be
         authorized for issuance upon exercise in full of the Rights, the 30-day
         period set forth above may be extended to the extent necessary, but not
         more than ninety (90) days after the Section 11(a)(ii) Trigger Date, in
         order that the Company may seek shareholder approval for the
         authorization of such additional shares (such period, as it may be
         extended, being referred to herein as the "Substitution Period"). To
         the extent that the Company determines that some action need be taken
         pursuant to the first and/or second sentences of this Section
         11(a)(iii), the Company (x) shall provide, subject to Section 7(e)
         hereof, that such action shall apply uniformly to all outstanding
         Rights and (y) may suspend the exercisability of the Rights until the
         expiration of the Substitution Period in order to seek any
         authorization of additional shares and/or to decide the appropriate
         form of distribution to be made pursuant to such first sentence and to
         determine the value thereof. In the event of any such suspension, the
         Company shall issue a public announcement stating that the
         exercisability of the Rights has been temporarily suspended and a
         public announcement at such time as the suspension is no longer in
         effect. For purposes of this Section 11(a)(iii), the value of the
         Preferred Stock shall be the Fair Market Value (as

                                       18

<PAGE>   22



         determined pursuant to Section 11(d) hereof) per share of the Preferred
         Stock on the Section 11(a)(ii) Trigger Date and the value of any
         Preferred Stock Equivalent shall be deemed to have the same value as
         the Preferred Stock on such date.

                  (b) If the Company shall fix a record date for the issuance of
rights, options or warrants to all holders of Preferred Stock entitling them
(for a period expiring within forty-five (45) calendar days after such record
date) to subscribe for or purchase Preferred Stock (or securities having the
same or more favorable rights, privileges and preferences as the shares of
Preferred Stock ("Preferred Stock Equivalents")) or securities convertible into
Preferred Stock or Preferred Stock Equivalents at a price per share of Preferred
Stock or per share of Preferred Stock Equivalents (or having a conversion price
per share, if a security convertible into Preferred Stock or Preferred Stock
Equivalents) less than the Fair Market Value (as determined pursuant to Section
11(d) hereof) per share of Preferred Stock on such record date, the Exercise
Price to be in effect after such record date shall be determined by multiplying
the Exercise Price in effect immediately prior to such record date by a
fraction, the numerator of which shall be the number of shares of Preferred
Stock outstanding on such record date, plus the number of shares of Preferred
Stock which the aggregate offering price of the total number of shares of
Preferred Stock and/or Preferred Stock Equivalents to be offered (and the
aggregate initial conversion price of the convertible securities so to be
offered) would purchase at such Fair Market Value and the denominator of which
shall be the number of shares of Preferred Stock outstanding on such record
date, plus the number of additional shares of Preferred Stock and Preferred
Stock Equivalents to be offered for subscription or purchase (or into which the
convertible securities so to be offered are initially convertible); PROVIDED,
HOWEVER, that in no event shall the consideration to be paid upon the exercise
of a Right be less than the aggregate par value of the shares of stock of the
Company issuable upon exercise of a Right. In case such subscription price may
be paid in a consideration part or all of which shall be in a form other than
cash, the value of such consideration shall be the Fair Market Value thereof
determined in accordance with Section 11(d) hereof. Shares of Preferred Stock
owned by or held for the account of the Company shall not be deemed outstanding
for the purpose of any such computation. Such adjustments shall be made
successively whenever such a record date is fixed; and in the event that such
rights or warrants are not so issued, the Exercise Price shall be adjusted to be
the Exercise Price which would then be in effect if such record date had not
been fixed.

                  (c) If the Company shall fix a record date for the making of a
distribution to all holders of Preferred Stock (including any such distribution
made in connection with a consolidation or merger in which the Company is the
continuing or surviving corporation), of evidences of indebtedness, cash (other
than a regular periodic cash dividend out of the earnings or retained earnings
of the Company), assets (other than a dividend payable in Preferred Stock, but
including any dividend payable in stock other than Preferred Stock) or
convertible securities, subscription rights or warrants (excluding those
referred to in Section 11(b)), the Exercise Price to be in effect after such
record date shall be determined by multiplying the Exercise Price in effect
immediately prior to such record date by a fraction, the numerator of which
shall be the Fair Market Value (as determined pursuant to Section 11(d) hereof)
per one

                                       19

<PAGE>   23



one-thousandth of a share of Preferred Stock on such record date, less the Fair
Market Value (as determined pursuant to Section 11(d) hereof) of the portion of
the cash, assets or evidences of indebtedness so to be distributed or of such
convertible securities, subscription rights or warrants applicable to one
one-thousandth of a share of Preferred Stock and the denominator of which shall
be the Fair Market Value (as determined pursuant to Section 11(d) hereof) per
one one-thousandth of a share of Preferred Stock; PROVIDED, HOWEVER, that in no
event shall the consideration to be paid upon the exercise of a Right be less
than the aggregate par value of the shares of stock of the Company issuable upon
exercise of a Right. Such adjustments shall be made successively whenever such a
record date is fixed; and in the event that such distribution is not so made,
the Exercise Price shall again be adjusted to be the Exercise Price which would
be in effect if such record date had not been fixed.

                  (d) For the purpose of this Agreement, the "Fair Market Value"
of any share of Preferred Stock, Common Stock or any other stock or any Right or
other security or any other property shall be determined as provided in this
Section 11(d).

                           (i) In the case of a publicly-traded stock or other
                  security, the Fair Market Value on any date shall be deemed to
                  be the average of the daily closing prices per share of such
                  stock or per unit of such other security for the 30
                  consecutive Trading Days (as such term is hereinafter defined)
                  immediately prior to such date; PROVIDED, HOWEVER, that in the
                  event that the Fair Market Value per share of any share of
                  stock is determined during a period following the announcement
                  by the issuer of such stock of (x) a dividend or distribution
                  on such stock payable in shares of such stock or securities
                  convertible into shares of such stock or (y) any subdivision,
                  combination or reclassification of such stock, and prior to
                  the expiration of the 30 Trading Day period after the
                  ex-dividend date for such dividend or distribution, or the
                  record date for such subdivision, combination or
                  reclassification, then, and in each such case, the Fair Market
                  Value shall be properly adjusted to take into account
                  ex-dividend trading. The closing price for each day shall be
                  the last sale price, regular way, or, in case no such sale
                  takes place on such day, the average of the closing bid and
                  asked prices, regular way, in either case as reported in the
                  principal consolidated transaction reporting system with
                  respect to securities listed or admitted to trading on the New
                  York Stock Exchange or, if the securities are not listed or
                  admitted to trading on the New York Stock Exchange, as
                  reported in the principal consolidated transaction reporting
                  system with respect to securities listed on the principal
                  national securities exchange on which such security is listed
                  or admitted to trading; or, if not listed or admitted to
                  trading on any national securities exchange, the last quoted
                  price (or, if not so quoted, the average of the last quoted
                  high bid and low asked prices) in the over-the-counter market,
                  as reported by NASDAQ or such other system then in use; or, if
                  on any such date no bids for such security are quoted by any
                  such organization, the average of the closing bid and asked
                  prices as furnished by a professional market maker making a
                  market in such security selected by the Board of

                                       20

<PAGE>   24



                  Directors of the Company. If on any such date no market maker
                  is making a market in such security, the Fair Market Value of
                  such security on such date shall be determined reasonably and
                  with utmost good faith to the holders of the Rights by the
                  Board of Directors of the Company, PROVIDED, HOWEVER, that if
                  at the time of such determination there is an Acquiring
                  Person, the Fair Market Value of such security on such date
                  shall be determined by a nationally recognized investment
                  banking firm selected by the Board of Directors of the
                  Company, which determination shall be described in a statement
                  filed with the Rights Agent and shall be binding on the Rights
                  Agent and the holders of the Rights. The term "Trading Day"
                  shall mean a day on which the principal national securities
                  exchange on which such security is listed or admitted to
                  trading is open for the transaction of business or, if such
                  security is not listed or admitted to trading on any national
                  securities exchange, a Business Day.

                           (ii) If a security is not publicly held or not so
                  listed or traded, "Fair Market Value" shall mean the fair
                  value per share of stock or per other unit of such security,
                  determined reasonably and with utmost good faith to the
                  holders of the Rights by the Board of Directors of the
                  Company; PROVIDED, HOWEVER, that if at the time of such
                  determination there is an Acquiring Person, the Fair Market
                  Value of such security on such date shall be determined by a
                  nationally recognized investment banking firm selected by the
                  Board of Directors of the Company, which determination shall
                  be described in a statement filed with the Rights Agent and
                  shall be binding on the Rights Agent and the holders of the
                  Rights; PROVIDED, HOWEVER, that for the purposes of making any
                  adjustment provided for by Section 11(a)(ii) hereof, the Fair
                  Market Value of a share of Preferred Stock shall not be less
                  than the product of the then Fair Market Value of a share of
                  Common Stock multiplied by the higher of the then Dividend
                  Multiple or Vote Multiple (as both of such terms are defined
                  in the terms of the Series B Junior Participating Cumulative
                  Preferred Stock attached hereto as EXHIBIT A) applicable to
                  the Preferred Stock and shall not exceed 105% of the product
                  of the then Fair Market Value of a share of Common Stock
                  multiplied by the higher of the then Dividend Multiple or Vote
                  Multiple applicable to the Preferred Stock.

                           (iii) In the case of property other than securities,
                  the Fair Market Value thereof shall be determined reasonably
                  and with utmost good faith to the holders of Rights by the
                  Board of Directors of the Company; PROVIDED, HOWEVER, that if
                  at the time of such determination there is an Acquiring
                  Person, the Fair Market Value of such property on such date
                  shall be determined by a nationally recognized investment
                  banking firm selected by the Board of Directors of the
                  Company, which determination shall be described in a statement
                  filed with the Rights Agent and shall be binding upon the
                  Rights Agent and the holders of the Rights.


                                       21

<PAGE>   25



                  (e) Anything herein to the contrary notwithstanding, no
adjustment in the Exercise Price shall be required unless such adjustment would
require an increase or decrease of at least 1% in the Exercise Price; PROVIDED,
HOWEVER, that any adjustments which by reason of this Section 11(e) are not
required to be made shall be carried forward and taken into account in any
subsequent adjustment. All calculations under this Section 11 shall be made to
the nearest cent or to the nearest hundred-thousandth of a share of Common Stock
of the Company or ten-millionth of a share of Preferred Stock, as the case may
be, or to such other figure as the Board of Directors of the Company may deem
appropriate. Notwithstanding the first sentence of this Section 11(e), any
adjustment required by this Section 11 shall be made no later than the earlier
of (i) three (3) years from the date of the transaction which mandates such
adjustment or (ii) the Expiration Date.

                  (f) If as a result of any provision of Section 11(a) or
Section 13(a) hereof, the holder of any Right thereafter exercised shall become
entitled to receive any shares of capital stock of the Company other than
Preferred Stock, thereafter the number of such other shares so receivable upon
exercise of any Right shall be subject to adjustment from time to time in a
manner and on terms as nearly equivalent as practicable to the provisions with
respect to the Preferred Stock contained in Section 11(a), (b), (c), (d), (e),
(g) through (k) and (m), inclusive, and the provisions of Sections 7, 9, 10, 13
and 14 hereof with respect to the Preferred Stock shall apply on like terms to
any such other shares.

                  (g) All Rights originally issued by the Company subsequent to
any adjustment made to the Exercise Price hereunder shall evidence the right to
purchase, at the adjusted Exercise Price, the number of one one-thousandths of a
share of Preferred Stock (or other securities or amount of cash or combination
thereof) purchasable from time to time hereunder upon exercise of the Rights,
all subject to further adjustment as provided herein.

                  (h) Unless the Company shall have exercised its election as
provided in Section 11(i), upon each adjustment of the Exercise Price as a
result of the calculations made in Section 11(b) and (c), each Right outstanding
immediately prior to the making of such adjustment shall thereafter evidence the
right to purchase, at the adjusted Exercise Price, that number of one
one-thousandths of a share of Preferred Stock (calculated to the nearest
ten-millionth) as the Board of Directors of the Company determines is
appropriate to preserve the economic value of the Rights, including, by way of
example, that number obtained by (i) multiplying (x) the number of one
one-thousandths of a share of Preferred Stock for which a Right may be
exercisable immediately prior to this adjustment by (y) the Exercise Price in
effect immediately prior to such adjustment of the Exercise Price and (ii)
dividing the product so obtained by the Exercise Price in effect immediately
after such adjustment of the Exercise Price.

                  (i) The Company may elect on or after the date of any
adjustment of the Exercise Price to adjust the number of Rights, in substitution
for any adjustment in the number of shares of Preferred Stock purchasable upon
the exercise of a Right. Each of the Rights outstanding after the adjustment in
the number of Rights shall be exercisable for the number of

                                       22

<PAGE>   26



one one-thousandths of a share of Preferred Stock for which a Right was
exercisable immediately prior to such adjustment. Each Right held of record
prior to such adjustment of the number of Rights shall become that number of
Rights (calculated to the nearest hundred-thousandth) obtained by dividing the
Exercise Price in effect immediately prior to adjustment of the Exercise Price
by the Exercise Price in effect immediately after adjustment of the Exercise
Price. The Company shall make a public announcement of its election to adjust
the number of Rights, indicating the record date for the adjustment, and, if
known at the time, the amount of the adjustment to be made. This record date may
be the date on which the Exercise Price is adjusted or any day thereafter, but,
if the Right Certificates have been issued, shall be at least ten (10) days
later than the date of the public announcement. If Right Certificates have been
issued, upon each adjustment of the number of Rights pursuant to this Section
11(i), the Company shall, as promptly as practicable, cause to be distributed to
holders of record of Right Certificates on such record date Right Certificates
evidencing, subject to Section 14 hereof, the additional Rights to which such
holders shall be entitled as a result of such adjustment, or, at the option of
the Company, shall cause to be distributed to such holders of record in
substitution and replacement for the Right Certificates held by such holders
prior to the date of adjustment, and upon surrender thereof, if required by the
Company, new Right Certificates evidencing all the Rights to which such holders
shall be entitled after such adjustment. Right Certificates so to be distributed
shall be issued, executed and countersigned in the manner provided for herein
(and may bear, at the option of the Company, the adjusted Exercise Price) and
shall be registered in the names of the holders of record of Right Certificates
on the record date specified in the public announcement.

                  (j) Irrespective of any adjustment or change in the Exercise
Price or the number of one one-thousandths of a share of Preferred Stock
issuable upon the exercise of the Rights, the Right Certificates theretofore and
thereafter issued may continue to express the Exercise Price per share and the
number of shares which were expressed in the initial Right Certificates issued
hereunder without prejudice to any adjustment or change.

                  (k) Before taking any action that would cause an adjustment
reducing the Exercise Price below the then stated value, if any, of the number
of one one-thousandths of a share of Preferred Stock issuable upon exercise of
the Rights, the Company shall take any corporate action which may, in the
opinion of its counsel, be necessary in order that the Company may validly and
legally issue fully paid and nonassessable shares of Preferred Stock at such
adjusted Exercise Price.

                  (l) In any case in which this Section 11 shall require that an
adjustment in the Exercise Price be made effective as of a record date for a
specified event, the Company may elect to defer until the occurrence of such
event the issuing to the holder of any Right exercised after such record date
the number of one one-thousandths of a share of Preferred Stock or other capital
stock or securities of the Company, if any, issuable upon such exercise over and
above the number of one one-thousandths of a share of Preferred Stock and other
capital stock or securities of the Company, if any, issuable upon such exercise
on the basis of the Exercise Price in effect prior to such adjustment; PROVIDED,
HOWEVER, that the Company

                                       23

<PAGE>   27



shall deliver to such holder a due bill or other appropriate instrument
evidencing such holder's right to receive such additional shares upon the
occurrence of the event requiring such adjustment.

                  (m) Anything in this Section 11 to the contrary
notwithstanding, the Company shall be entitled to make such reductions in the
Exercise Price, in addition to those adjustments expressly required by this
Section 11, as and to the extent that in its good faith judgment the Board of
Directors of the Company shall determine to be advisable in order that any
consolidation or subdivision of the Preferred Stock, issuance wholly for cash of
any shares of Preferred Stock at less than the Fair Market Value, issuance
wholly for cash of shares of Preferred Stock or securities which by their terms
are convertible into or exchangeable for shares of Preferred Stock, stock
dividends or issuance of rights, options or warrants referred to hereinabove in
this Section 11, hereafter made by the Company to holders of its Preferred
Stock, shall not be taxable to such shareholders.

                  (n) The Company covenants and agrees that it shall not, at any
time after the Distribution Date and so long as the Rights have not been
redeemed pursuant to Section 23 hereof or exchanged pursuant to Section 24
hereof, (i) consolidate with (other than a Subsidiary of the Company in a
transaction that complies with the proviso at the end of this sentence), (ii)
merge with or into, or (iii) sell or transfer (or permit any Subsidiary to sell
or transfer), in one transaction or a series of related transactions, assets or
earning power aggregating 50% or more of the assets or earning power of the
Company and its Subsidiaries taken as a whole, to any other Person or Persons
(other than the Company and/or any of its Subsidiaries in one or more
transactions each of which complies with the proviso at the end of this
sentence) if (x) at the time of or immediately after such consolidation, merger
or sale there are any rights, warrants or other instruments outstanding or
agreements or arrangements in effect which would substantially diminish or
otherwise eliminate the benefits intended to be afforded by the Rights, or (y)
prior to, simultaneously with or immediately after such consolidation, merger or
sale the shareholders of such Person or Persons shall have received a
distribution of Rights previously owned by such Person or Persons or any of
their Affiliates and Associates; PROVIDED, HOWEVER, that this Section 11(n)
shall not affect the ability of any Subsidiary of the Company to consolidate
with, or merge with or into, or sell or transfer assets or earning power to, any
other Subsidiary of the Company. The Company further covenants and agrees that
after the Distribution Date it will not, except as permitted by Section 23 or
Section 27 hereof, take (or permit any Subsidiary to take) any action if at the
time such action is taken it is reasonably foreseeable that such action will
substantially diminish or otherwise eliminate the benefits intended to be
afforded by the Rights.

                  (o) Notwithstanding anything in this Agreement to the
contrary, in the event the Company shall at any time after the date of this
Agreement and prior to the Distribution Date (i) declare or pay any dividend on
the outstanding Common Stock of the Company payable in shares of Common Stock of
the Company or (ii) effect a subdivision, combination or consolidation of the
outstanding shares of Common Stock of the Company (by reclassification or
otherwise than by payment of dividends in shares of Common Stock of the

                                       24

<PAGE>   28



Company) into a greater or lesser number of shares of Common Stock of the
Company, then in any such case (A) the number of one one-thousandths of a share
of Preferred Stock purchasable after such event upon proper exercise of each
Right shall be determined by multiplying the number of one one-thousandths of a
share of Preferred Stock so purchasable immediately prior to such event by a
fraction, the numerator of which is the number of shares of Common Stock of the
Company outstanding immediately prior to such event and the denominator of which
is the number of shares of Common Stock of the Company outstanding immediately
after such event, and (B) each share of Common Stock of the Company outstanding
immediately after such event shall have issued with respect to it that number of
Rights which each share of Common Stock of the Company outstanding immediately
prior to such event had issued with respect to it. The adjustments provided for
in this Section 11(o) shall be made successively whenever such a dividend is
declared or paid or such a subdivision, combination or consolidation is
effected.

                  (p) The exercise of Rights under Section 11(a)(ii) shall only
result in the loss of rights under Section 11(a)(ii) to the extent so exercised
and shall not otherwise affect the rights of holders of Right Certificates under
this Rights Agreement, including rights to purchase securities of any other
Person or Persons following a Section 13 Event which has occurred or may
thereafter occur, as set forth in Section 13 hereof. Upon exercise of a Right
Certificate under Section 11(a)(ii), the Rights Agent shall return such Right
Certificate duly marked to indicate that such exercise has occurred.

         Section 12. CERTIFICATE OF ADJUSTED EXERCISE PRICE OR NUMBER OF SHARES.
Whenever an adjustment is made as provided in Section 11 or Section 13 hereof,
the Company shall (a) promptly prepare a certificate setting forth such
adjustment and a brief statement of the facts accounting for such adjustment,
(b) promptly file with the Rights Agent and with each transfer agent for the
Preferred Stock and the Common Stock of the Company a copy of such certificate
and (c) mail a brief summary thereof to each holder of a Right Certificate (or,
if prior to the Distribution Date, to each holder of a certificate representing
shares of Common Stock of the Company) in accordance with Section 26 hereof. The
Rights Agent shall be fully protected in relying on any such certificate and on
any adjustment contained therein and shall not be deemed to have knowledge of
any such adjustment unless and until it shall have received such certificate.

         Section 13. CONSOLIDATION, MERGER OR SALE OR TRANSFER OF ASSETS OR
EARNING POWER.

                  (a) In the event that, following the Stock Acquisition Date,
directly or indirectly, (x) the Company shall consolidate with, or merge with
and into, any other Person (other than a Subsidiary of the Company in a
transaction which is not prohibited by Section 11(n) hereof), and the Company
shall not be the continuing or surviving corporation of such consolidation or
merger, (y) any other Person (other than a Subsidiary of the Company in a
transaction which is not prohibited by the proviso at the end of the first
sentence of Section 11(n) hereof) shall consolidate with the Company, or merge
with and into the Company and the Company shall be the continuing or surviving
corporation of such merger and, in

                                       25

<PAGE>   29



connection with such merger, all or part of the shares of Common Stock of the
Company shall be changed into or exchanged for stock or other securities of any
other Person or cash or any other property, or (z) the Company shall sell,
mortgage or otherwise transfer (or one or more of its Subsidiaries shall sell,
mortgage or otherwise transfer), in one transaction or a series of related
transactions, assets or earning power aggregating 50% or more of the assets or
earning power of the Company and its Subsidiaries (taken as a whole) to any
other Person (other than the Company or any Subsidiary of the Company in one or
more transactions, each of which is not prohibited by the proviso at the end of
the first sentence of Section 11(n) hereof), then, and in each such case, proper
provision shall be made so that: (i) each holder of a Right, except as provided
in Section 7(e) hereof, shall have the right to receive, upon the exercise
thereof at the then current Exercise Price in accordance with the terms of this
Agreement, such number of validly authorized and issued, fully paid and
nonassessable shares of freely tradeable Common Stock of such other Person
(including the Company as successor thereto or as the surviving corporation),
free and clear of rights of call or first refusal, liens, encumbrances, transfer
restrictions or other adverse claims, as shall be equal to the result obtained
by (1) multiplying the then current Exercise Price by the number of one
one-thousandths of a share of Preferred Stock for which a Right is exercisable
immediately prior to the first occurrence of a Section 13 Event, and dividing
that product by (2) 50% of the Fair Market Value (determined pursuant to Section
11(d) hereof) per share of the Common Stock of such other Person on the date of
consummation of such consolidation, merger, sale or transfer; (ii) the issuer of
such Common Stock shall thereafter be liable for, and shall assume, by virtue of
such consolidation, merger, sale, mortgage or transfer, all the obligations and
duties of the Company pursuant to this Agreement; (iii) the term "Company" shall
thereafter be deemed to refer to such issuer, it being specifically intended
that the provisions of Section 11 hereof shall apply to such issuer; and (iv)
such issuer shall take such steps (including, but not limited to, the
reservation of a sufficient number of shares of its Common Stock to permit
exercise of all outstanding Rights in accordance with this Section 13(a) and the
making of payments in cash and/or other securities in accordance with Section
11(a)(iii) hereof) in connection with such consummation as may be necessary to
assure that the provisions hereof shall thereafter be applicable, as nearly as
reasonably may be, in relation to its shares of Common Stock thereafter
deliverable upon the exercise of the Rights.

         (b) The Company shall not consummate any such consolidation, merger,
sale or transfer with any such Person referred to in clauses (x), (y) or (z) of
Section 13(a) unless prior thereto (x) such other Person shall have a sufficient
number of authorized shares of its Common Stock, which have not been issued or
reserved for issuance, to permit the exercise in full of the Rights in
accordance with this Section 13, and (y) the Company and such other Person shall
have executed and delivered to the Rights Agent a supplemental agreement
providing for the terms set forth in Section 13(a) and (b) and further providing
that, as soon as practicable after the date of any consolidation, merger, sale
or transfer of assets mentioned in Section 13(a), such other Person at its own
expense will:

                           (i) prepare and file a registration statement under
         the Securities Act with respect to the Rights and the securities
         purchasable upon exercise of the Rights on

                                       26

<PAGE>   30



         an appropriate form, cause such registration statement to become
         effective as soon as practicable after such filing and cause such
         registration statement to remain effective (with a prospectus that at
         all times meets the requirements of the Securities Act) until the
         Expiration Date;

                           (ii) qualify or register the Rights and the
         securities purchasable upon exercise of the Rights under the blue sky
         laws of such jurisdictions as may be necessary or appropriate;

                           (iii) list (or continue the listing of) the Rights
         and the securities purchasable upon exercise of the Rights on a
         national securities exchange or to meet the eligibility requirements
         for quotation on NASDAQ; and

                           (iv) deliver to holders of the Rights historical
         financial statements for such other Person and each of its Affiliates
         which comply in all respects with the requirements for registration on
         Form 10 under the Exchange Act.

                  (c) In case any Person which is to be a party to a transaction
referred to in this Section 13 has a provision in any of its authorized
securities or in its certificate of incorporation or by-laws or other instrument
governing its affairs, which provision would have the effect of (i) causing such
Person to issue (other than to holders of Rights pursuant to this Section 13),
in connection with, or as a consequence of, the consummation of a transaction
referred to in this Section 13, shares of Common Stock of such Person at less
than the then current Fair Market Value (determined pursuant to Section 11(d))
or securities exercisable for, or convertible into, Common Stock of such Person
at less than such Fair Market Value, or (ii) providing for any special payment,
tax or similar provisions in connection with the issuance of the Common Stock of
such Person pursuant to the provisions of this Section 13, then, in such event,
the Company shall not consummate any such transaction unless prior thereto the
Company and such Person shall have executed and delivered to the Rights Agent a
supplemental agreement providing that the provision in question of such Person
shall have been canceled, waived or amended, or that the authorized securities
shall be redeemed, so that the applicable provision will have no effect in
connection with, or as a consequence of, the consummation of the proposed
transaction.

The provisions of this Section 13 shall similarly apply to successive mergers or
consolidations or sales or other transfers.

         Section 14.  FRACTIONAL RIGHTS AND FRACTIONAL SHARES.

                  (a) The Company shall not be required to issue fractions of
Rights, except prior to the Distribution Date as provided in Section 11(o)
hereof, or to distribute Right Certificates which evidence fractional Rights. If
the Company elects not to issue such fractional Rights, the Company shall pay,
in lieu of such fractional Rights, to the registered holders of the Right
Certificates with regard to which such fractional Rights would otherwise

                                       27

<PAGE>   31



be issuable, an amount in cash equal to the same fraction of the Fair Market
Value of a whole Right, as determined pursuant to Section 11(d) hereof.

                  (b) The Company shall not be required to issue fractions of
shares of Preferred Stock (other than fractions which are integral multiples of
one one-thousandth of a share of Preferred Stock) upon exercise of the Rights or
to distribute certificates which evidence fractional shares of Preferred Stock
(other than fractions which are integral multiples of one one-thousandth of a
share of Preferred Stock). In lieu of fractional shares of Preferred Stock that
are not integral multiples of one one-thousandth of a share of Preferred Stock,
the Company may pay to the registered holders of Right Certificates at the time
such Rights are exercised as herein provided an amount in cash equal to the same
fraction of the Fair Market Value of one one-thousandth of a share of Preferred
Stock. For purposes of this Section 14(b), the Fair Market Value of one
one-thousandth of a share of Preferred Stock shall be determined pursuant to
Section 11(d) hereof for the Trading Day immediately prior to the date of such
exercise.

                  (c) The holder of a Right by the acceptance of the Rights
expressly waives his right to receive any fractional Rights or any fractional
shares upon exercise of a Right, except as permitted by this Section 14.

         Section 15. RIGHTS OF ACTION. All rights of action in respect of this
Agreement, other than rights of action vested in the Rights Agent pursuant to
Sections 18 and 20 hereof, are vested in the respective registered holders of
the Right Certificates (or, prior to the Distribution Date, the registered
holders of the Common Stock of the Company); and any registered holder of any
Right Certificate (or, prior to the Distribution Date, of the Common Stock of
the Company), without the consent of the Rights Agent or of the holder of any
other Right Certificate (or, prior to the Distribution Date, of the Common Stock
of the Company), may, in such registered holder's own behalf and for such
registered holder's own benefit, enforce, and may institute and maintain any
suit, action or proceeding against the Company to enforce, or otherwise act in
respect of, his right to exercise the Right evidenced by such Right Certificate
in the manner provided in such Right Certificate and in this Agreement. Without
limiting the foregoing or any remedies available to the holders of Rights, it is
specifically acknowledged that the holders of Rights would not have an adequate
remedy at law for any breach of this Agreement and shall be entitled to specific
performance of the obligations hereunder and injunctive relief against actual or
threatened violations of the obligations hereunder of any Person subject to this
Agreement. Holders of Rights shall be entitled to recover the reasonable costs
and expenses, including attorneys' fees, incurred by them in any action to
enforce the provisions of this Agreement.

         Section 16. AGREEMENT OF RIGHT HOLDERS. Every holder of a Right, by
accepting the same, consents and agrees with the Company and the Rights Agent
and with every other holder of a Right that:


                                       28

<PAGE>   32



                  (a) prior to the Distribution Date, each Right will be
transferable only simultaneously and together with the transfer of shares of
Common Stock of the Company;

                  (b) after the Distribution Date, the Right Certificates are
transferable only on the registry books of the Rights Agent if surrendered at
the office or offices of the Rights Agent designated for such purpose, duly
endorsed or accompanied by a proper instrument of transfer;

                  (c) subject to Sections 6(a) and 7(f), the Company and the
Rights Agent may deem and treat the person in whose name a Right Certificate
(or, prior to the Distribution Date, the associated certificate representing
Common Stock of the Company) is registered as the absolute owner thereof and of
the Rights evidenced thereby (notwithstanding any notations of ownership or
writing on the Right Certificates or the associated certificate representing
Common Stock of the Company made by anyone other than the Company or the Rights
Agent) for all purposes whatsoever, and, subject to the last sentence of Section
7(e), neither the Company nor the Rights Agent shall be affected by any notice
to the contrary; and

                  (d) notwithstanding anything in this Agreement to the
contrary, neither the Company nor the Rights Agent shall have any liability to
any holder of a Right or other Person as the result of its inability to perform
any of its obligations under this Agreement by reason of any preliminary or
permanent injunction or other order, decree or ruling issued by a court of
competent jurisdiction or by a governmental, regulatory or administrative agency
or commission, or any statute, rule, regulation or executive order promulgated
or enacted by any governmental authority prohibiting or otherwise restraining
performance of such obligations; PROVIDED, HOWEVER, that the Company must use
its best efforts to have any such order, decree or ruling lifted or otherwise
overturned as soon as possible.

         Section 17. RIGHT CERTIFICATE HOLDER NOT DEEMED A SHAREHOLDER. No
holder, as such, of any Right Certificate shall be entitled to vote, receive
dividends or be deemed for any purpose the holder of the shares of Preferred
Stock or any other securities of the Company which may at any time be issuable
on the exercise of the Rights represented thereby, nor shall anything contained
herein or in any Right Certificate be construed to confer upon the holder of any
Right Certificate, as such, any of the rights of a shareholder of the Company or
any right to vote for the election of directors or upon any matter submitted to
shareholders at any meeting thereof, or to give or withhold consent to any
corporate action, or to receive notice of meetings or other actions affecting
shareholders (except as provided in Section 25 hereof), or to receive dividends
or subscription rights, or otherwise, until the Right or Rights evidenced by
such Right Certificate shall have been exercised in accordance with the
provisions hereof.

         Section 18.  CONCERNING THE RIGHTS AGENT.

                  (a) The Company agrees to pay to the Rights Agent such
compensation as shall be agreed to in writing between the Company and the Rights
Agent for all services rendered by it hereunder and, from time to time, on
demand of the Rights Agent, its

                                       29

<PAGE>   33



reasonable expenses and counsel fees and disbursements and other disbursements
incurred in the administration and execution of this Agreement and the exercise
and performance of its duties hereunder. The Company also agrees to indemnify
the Rights Agent for, and to hold it harmless against, any loss, liability, or
expense, incurred without gross negligence, bad faith or willful misconduct on
the part of the Rights Agent, for anything done or omitted by the Rights Agent
in connection with the acceptance and administration of this Agreement,
including the costs and expenses of defending against any claim of liability
arising therefrom, directly or indirectly. The provisions of this Section 18(a)
shall survive the expiration of the Rights and the termination of this
Agreement.

                  (b) The Rights Agent shall be protected and shall incur no
liability for or in respect of any action taken, suffered or omitted by it in
connection with its administration of this Agreement in reliance upon any Right
Certificate or certificate representing Common Stock of the Company, Preferred
Stock, or other securities of the Company, instrument of assignment or transfer,
power of attorney, endorsement, affidavit, letter, notice, direction, consent,
certificate, statement, or other paper or document believed by it in good faith
and without gross negligence to be genuine and to be signed and executed by the
proper Person or Persons.

                  (c) The Rights Agent shall not be liable for consequential
damages under any provision of this Agreement or for any consequential damages
arising out of any act or failure to act hereunder.

         Section 19.  MERGER OR CONSOLIDATION OR CHANGE OF NAME OF RIGHTS AGENT.

                  (a) Any corporation into which the Rights Agent or any
successor Rights Agent may be merged or with which it may be consolidated, or
any corporation resulting from any merger or consolidation to which the Rights
Agent or any successor Rights Agent shall be a party, or any corporation
succeeding to the corporate trust or shareholder services business of the Rights
Agent or any successor Rights Agent, shall be the successor to the Rights Agent
under this Agreement without the execution or filing of any paper or any further
act on the part of any of the parties hereto, provided that such corporation
would be eligible for appointment as a successor Rights Agent under the
provisions of Section 21 hereof. In case at the time such successor Rights Agent
shall succeed to the agency created by this Agreement, any of the Right
Certificates shall have been countersigned but not delivered, any such successor
Rights Agent may adopt the countersignature of the predecessor Rights Agent and
deliver such Right Certificates so countersigned; and in case at that time any
of the Right Certificates shall not have been countersigned, any successor
Rights Agent may countersign such Right Certificates either in the name of the
predecessor or in the name of the successor Rights Agent; and in all such cases
such Right Certificates shall have the full force provided in the Right
Certificates and in this Agreement.

                  (b) In case at any time the name of the Rights Agent shall be
changed and at such time any of the Right Certificates shall have been
countersigned but not delivered, the

                                       30

<PAGE>   34



Rights Agent may adopt the countersignature under its prior name and deliver
Right Certificates so countersigned; and in case at that time any of the Right
Certificates shall not have been countersigned, the Rights Agent may countersign
such Right Certificates either in its prior name or in its changed name; and in
all such cases such Right Certificates shall have the full force provided in the
Right Certificates and in this Agreement.

         Section 20. DUTIES OF RIGHTS AGENT. The Rights Agent undertakes the
duties and obligations expressly imposed by this Agreement upon the following
terms and conditions, by all of which the Company and the holders of Right
Certificates, by their acceptance thereof, shall be bound:

                  (a) The Rights Agent may consult with legal counsel selected
by it (who may be legal counsel for the Company), and the opinion of such
counsel shall be full and complete authorization and protection to the Rights
Agent as to any action taken or omitted by it in good faith and in accordance
with such opinion.

                  (b) Whenever in the performance of its duties under this
Agreement the Rights Agent shall deem it necessary or desirable that any fact or
matter (including, without limitation, the identity of any Acquiring Person and
the determination of "Fair Market Value") be proved or established by the
Company prior to taking or suffering any action hereunder, such fact or matter
(unless other evidence in respect thereof shall be herein specifically
prescribed) may be deemed to be conclusively proved and established by a
certificate signed by a person believed by the Rights Agent to be the Chairman
of the Board of Directors, a Vice Chairman of the Board of Directors, the
President, a Vice President, the Treasurer, any Assistant Treasurer, the
Secretary or an Assistant Secretary of the Company and delivered to the Rights
Agent. Any such certificate shall be full authorization to the Rights Agent for
any action taken or suffered in good faith by it under the provisions of this
Agreement in reliance upon such certificate.

                  (c) The Rights Agent shall be liable hereunder only for its
own gross negligence, bad faith or willful misconduct.

                  (d) The Rights Agent shall not be liable for or by reason of
any of the statements of fact or recitals contained in this Agreement or in the
Right Certificates (except its countersignature thereof) or be required to
verify the same, but all such statements and recitals are and shall be deemed to
have been made by the Company only.

                  (e) The Rights Agent shall not be under any responsibility in
respect of the validity of this Agreement or the execution and delivery hereof
(except the due execution hereof by the Rights Agent) or in respect of the
validity or execution of any Right Certificate (except its countersignature
thereof); nor shall it be responsible for any breach by the Company of any
covenant or condition contained in this Agreement or in any Right Certificate;
nor shall it be responsible for any change in the exercisability of the Rights
(including the Rights becoming void pursuant to Section 7(e) hereof) or any
adjustment required under the

                                       31

<PAGE>   35



provisions of Sections 11, 13 or 23(c) hereof or responsible for the manner,
method or amount of any such adjustment or the ascertaining of the existence of
facts that would require any such adjustment (except with respect to the
exercise of Rights evidenced by Right Certificates after receipt of a
certificate describing any such adjustment furnished in accordance with Section
12 hereof), nor shall it be responsible for any determination by the Board of
Directors of the Company of the Fair Market Value of the Rights or Preferred
Stock pursuant to the provisions of Section 14 hereof; nor shall it by any act
hereunder be deemed to make any representation or warranty as to the
authorization or reservation of any shares of Common Stock of the Company or
Preferred Stock to be issued pursuant to this Agreement or any Right Certificate
or as to whether or not any shares of Common Stock of the Company or Preferred
Stock will, when so issued, be validly authorized and issued, fully paid and
nonassessable.

                  (f) The Company agrees that it will perform, execute,
acknowledge and deliver or cause to be performed, executed, acknowledged and
delivered all such further and other acts, instruments and assurances as may
reasonably be required by the Rights Agent for the carrying out or performing by
the Rights Agent of the provisions of this Agreement.

                  (g) The Rights Agent is hereby authorized and directed to
accept instructions with respect to the performance of its duties hereunder and
certificates delivered pursuant to any provision hereof from any person believed
by the Rights Agent to be the Chairman of the Board of Directors, any Vice
Chairman of the Board of Directors, the President, a Vice President, the
Secretary, an Assistant Secretary, the Treasurer or an Assistant Treasurer of
the Company, and is authorized to apply to such officers for advice or
instructions in connection with its duties, and it shall not be liable for any
action taken or suffered to be taken by it in good faith in accordance with
instructions of any such officer. Any application by the Rights Agent for
written instructions from the Company may, at the option of the Rights Agent,
set forth in writing any action proposed to be taken or omitted by the Rights
Agent under this Agreement and the date on or after which such action shall be
taken or such omission shall be effective. The Rights Agent shall not be liable
for any action taken by, or omission of, the Rights Agent in accordance with a
proposal included in such application on or after the date specified in such
application (which date shall not be less than five Business Days after the date
any officer of the Company actually receives such application, unless any such
officer shall have consented in writing to an earlier date) unless, prior to
taking any such action (or the effective date in the case of an omission), the
Rights Agent shall have received written instructions in response to such
application specifying the action to be taken or omitted.

                  (h) The Rights Agent and any shareholder, director, officer or
employee of the Rights Agent may buy, sell or deal in any of the Rights or other
securities of the Company or become pecuniarily interested in any transaction in
which the Company may be interested, or contract with or lend money to the
Company or otherwise act as fully and freely as though it were not the Rights
Agent under this Agreement. Nothing herein shall preclude the Rights Agent from
acting in any other capacity for the Company or for any other legal entity.

                  (i) The Rights Agent may execute and exercise any of the
rights or powers

                                       32

<PAGE>   36



hereby vested in it or perform any duty hereunder either itself or by or through
its attorneys or agents.

                  (j) No provision of this Agreement shall require the Rights
Agent to expend or risk its own funds or otherwise incur any financial liability
in the performance of any of its duties hereunder or in the exercise of its
rights if there shall be reasonable grounds for believing that repayment of such
funds or adequate indemnification against such risk or liability is not
reasonably assured to it.

                  (k) If, with respect to any Right Certificate surrendered to
the Rights Agent for exercise or transfer, the certificate attached to the form
of assignment or form of election to purchase, as the case may be, has either
not been completed or indicates an affirmative response to clause (1) or clause
(2) thereof, the Rights Agent shall not take any further action with respect to
such requested exercise or transfer without first consulting with the Company.

         Section 21. CHANGE OF RIGHTS AGENT. The Rights Agent or any successor
Rights Agent may resign and be discharged from its duties under this Agreement
upon thirty (30) days' notice in writing mailed to the Company by first class
mail. The Company may remove the Rights Agent or any successor Rights Agent
(with or without cause), effective immediately or on a specified date, by
written notice given to the Rights Agent or successor Rights Agent, as the case
may be, and to each transfer agent of the Common Stock of the Company and
Preferred Stock, and by giving notice to the holders of the Right Certificates
by any means reasonably determined by the Company to inform such holders of such
removal (including without limitation, by including such information in one or
more of the Company's reports to shareholders or reports or filings with the
Securities and Exchange Commission). If the Rights Agent shall resign or be
removed or shall otherwise become incapable of acting, the Company shall appoint
a successor to the Rights Agent. If the Company shall fail to make such
appointment within a period of thirty (30) days after giving notice of such
removal or after it has been notified in writing of such resignation or
incapacity by the resigning or incapacitated Rights Agent or by the holder of a
Right Certificate (who shall, with such notice, submit his Right Certificate for
inspection by the Company), then the incumbent Rights Agent or the registered
holder of any Right Certificate may apply to any court of competent jurisdiction
for the appointment of a new Rights Agent. Any successor Rights Agent, whether
appointed by the Company or by such a court, shall be (a) a corporation
organized and doing business under the laws of the United States or the State of
New York (or of any other state of the United States so long as such corporation
is authorized to do business as a banking institution in the State of New York),
in good standing, which is authorized under such laws to exercise stock transfer
or corporate trust powers and is subject to supervision or examination by
federal or state authority and which has at the time of its appointment as
Rights Agent a combined capital and surplus of at least $100,000,000 or (b) an
Affiliate of a corporation described in clause (a) of this sentence. After
appointment, the successor Rights Agent shall be vested with the same powers,
rights, duties and responsibilities as if it had been originally named as Rights
Agent without further act or deed; but the predecessor Rights Agent shall
deliver and transfer to the successor Rights Agent any property at the time held
by it hereunder, and execute and deliver

                                       33

<PAGE>   37



any further assurance, conveyance, act or deed necessary for the purpose. Not
later than the effective date of any such appointment, the Company shall file
notice thereof in writing with the predecessor Rights Agent and each transfer
agent of the Common Stock of the Company and the Preferred Stock, and mail a
notice thereof in writing to the registered holders of the Right Certificates.
Failure to give any notice provided for in this Section 21, however, or any
defect therein, shall not affect the legality or validity of the resignation or
removal of the Rights Agent or the appointment of the successor Rights Agent, as
the case may be.

         Section 22. ISSUANCE OF NEW RIGHT CERTIFICATES. Notwithstanding any of
the provisions of this Agreement or of the Rights to the contrary, the Company
may, at its option, issue new Right Certificates evidencing Rights in such form
as may be approved by the Board of Directors of the Company to reflect any
adjustment or change in the Exercise Price per share and the number or kind or
class of shares of stock or other securities or property purchasable under the
Right Certificates made in accordance with the provisions of this Agreement. In
addition, in connection with the issuance or sale of shares of Common Stock of
the Company following the Distribution Date and prior to the redemption or
expiration of the Rights, the Company (a) shall, with respect to shares of
Common Stock of the Company so issued or sold pursuant to the exercise of stock
options or under any employee plan or arrangement, or upon the exercise,
conversion or exchange of securities hereafter issued by the Company, and (b)
may, in any other case, if deemed necessary or appropriate by the Board of
Directors of the Company, issue Right Certificates representing the appropriate
number of Rights in connection with such issuance or sale; PROVIDED, HOWEVER,
that (i) no such Right Certificate shall be issued if, and to the extent that,
the Company shall be advised by counsel that such issuance would create a
significant risk of material adverse tax consequences to the Company or the
person to whom such Right Certificate would be issued, and (ii) no such Right
Certificate shall be issued if, and to the extent that, appropriate adjustments
shall otherwise have been made in lieu of the issuance thereof.

         Section 23.  REDEMPTION.

                  (a) The Board of Directors of the Company may, at its option,
redeem all but not less than all of the then outstanding Rights at a redemption
price of $0.01 per Right, appropriately adjusted to reflect any dividend
declared or paid on the Common Stock of the Company in shares of Common Stock of
the Company or any subdivision or combination of the outstanding shares of
Common Stock of the Company or similar event occurring after the date of this
Agreement (such redemption price, as adjusted from time to time, being
hereinafter referred to as the "Redemption Price"). The Rights may be redeemed
only until the earlier to occur of (i) the time at which any Person becomes an
Acquiring Person or (ii) the Final Expiration Date.

                  (b) Immediately upon the action of the Board of Directors of
the Company ordering the redemption of the Rights in accordance with Section 23
hereof, and without any further action and without any notice, the right to
exercise the Rights will terminate and the only right thereafter of the holders
of Rights shall be to receive the Redemption Price for each

                                       34

<PAGE>   38



Right so held. Promptly after the action of the Board of Directors of the
Company ordering the redemption of the Rights in accordance with Section 23
hereof, the Company shall give notice of such redemption to the Rights Agent and
the holders of the then outstanding Rights by mailing such notice to the Rights
Agent and to all such holders at their last addresses as they appear upon the
registry books of the Rights Agent or, prior to the Distribution Date, on the
registry books of the Transfer Agent for the Common Stock of the Company. Any
notice which is mailed in the manner herein provided shall be deemed given,
whether or not the holder receives the notice. The Company promptly shall mail a
notice of any such exchange to all of the holders of such Rights at their last
addresses as they appear upon the registry books of the Rights Agent. Any notice
which is mailed in the manner herein provided shall be deemed given, whether or
not the holder receives the notice. Each such notice of redemption will state
the method by which the payment of the Redemption Price will be made. Neither
the Company nor any of its Affiliates or Associates may redeem, acquire or
purchase for value any Rights at any time in any manner other than that
specifically set forth in this Section 23 or Section 24 hereof or in connection
with the purchase of shares of Common Stock of the Company prior to the
Distribution Date.

                  (c) The Company may, at its option, pay the Redemption Price
in cash, shares of Common Stock of the Company (based on the Fair Market Value
of the Common Stock of the Company as of the time of redemption) or any other
form of consideration deemed appropriate by the Board of Directors of the
Company.

         Section 24.  EXCHANGE.

                  (a) (i) The Board of Directors of the Company may, at its
                  option, at any time on or after the occurrence of a Section
                  11(a)(ii) Event, exchange all or part of the then outstanding
                  and exercisable Rights (which shall not include Rights that
                  have become void pursuant to the provisions of Section 7(e)
                  hereof) for shares of Common Stock of the Company at an
                  exchange ratio of one share of Common Stock of the Company per
                  Right, appropriately adjusted to reflect any stock split,
                  stock dividend or similar transaction occurring after the date
                  hereof (such exchange ratio being hereinafter referred to as
                  the "Section 24(a)(i) Exchange Ratio"). Notwithstanding the
                  foregoing, the Board of Directors of the Company shall not be
                  empowered to effect such exchange at any time after any Person
                  (other than an Exempt Person), together with all Affiliates
                  and Associates of such Person, becomes the Beneficial Owner of
                  50% or more of the Common Stock of the Company.

                           (ii) Notwithstanding the foregoing, the Board of
                  Directors of the Company may, at its option, at any time on or
                  after the occurrence of a Section 11(a)(ii) Event, exchange
                  all or part of the then outstanding and exercisable Rights
                  (which shall not include Rights that have become void pursuant
                  to the provisions of Section 7(e) hereof) for shares of Common
                  Stock of the Company at an exchange ratio specified in the
                  following sentence, as appropriately

                                       35

<PAGE>   39



                  adjusted to reflect any stock split, stock dividend or similar
                  transaction occurring after the date of this Agreement.
                  Subject to the adjustment described in the foregoing sentence,
                  each Right may be exchanged for that number of shares of
                  Common Stock of the Company obtained by dividing the Spread
                  (as defined in Section 11(a)(iii)) by the then Fair Market
                  Value per one one-thousandth of a share of Preferred Stock on
                  the earlier of (x) the date on which any person becomes an
                  Acquiring Person or (y) the date on which a tender or exchange
                  offer by any Person (other than an Exempt Person) is first
                  published or sent or given within the meaning of Rule 14d-4(a)
                  of the Exchange Act or any successor rule, if upon
                  consummation thereof such Person could become an Acquiring
                  Person (such exchange ratio being referred to herein as the
                  "Section 24(a)(ii) Exchange Ratio"). Notwithstanding the
                  foregoing, the Board of Directors of the Company shall not be
                  empowered to effect such exchange at any time after any Person
                  (other than an Exempt Person), together with all Affiliates
                  and Associates of such Person, becomes the Beneficial Owner of
                  50% or more of the Common Stock of the Company.

                  (b) Immediately upon the action of the Board of Directors of
the Company ordering the exchange of any Rights pursuant to subsection (a) of
this Section 24 and without any further action and without any notice, the right
to exercise such Rights shall terminate and the only right thereafter of a
holder of such Rights shall be to receive that number of shares of Common Stock
of the Company equal to the number of such Rights held by such holder multiplied
by the Section 24(a)(i) Exchange Ratio or the Section 24(a)(ii) Exchange Ratio,
as applicable. The Company shall promptly give notice of any such exchange in
accordance with Section 26 hereof and shall promptly mail a notice of any such
exchange to all of the holders of such Rights at their last addresses as they
appear upon the registry books of the Rights Agent; PROVIDED, HOWEVER, that the
failure to give, or any defect in, such notice shall not affect the validity of
such exchange. Any notice which is mailed in the manner herein provided shall be
deemed given, whether or not the holder receives the notice. Each such notice of
exchange will state the method by which the exchange of the shares of Common
Stock of the Company for Rights will be effected and, in the event of any
partial exchange, the number of Rights which will be exchanged. Any partial
exchange shall be effected pro rata based on the number of Rights (other than
Rights which have become void pursuant to the provisions of Section 7(e) hereof)
held by each holder of Rights.

                  (c) In any exchange pursuant to this Section 24, the Company,
at its option, may substitute Preferred Stock (or Preferred Stock Equivalent, as
such term is defined in Section 11(b) hereof) for Common Stock of the Company
exchangeable for Rights, at the initial rate of one one-thousandth of a share of
Preferred Stock (or Preferred Stock Equivalent) for each share of Common Stock
of the Company, as appropriately adjusted to reflect adjustments in the voting
rights of the Preferred Stock pursuant to the terms thereof, so that the
fraction of a share of Preferred Stock delivered in lieu of each share of Common
Stock of the Company shall have the same voting rights as one share of Common
Stock of the Company.


                                       36

<PAGE>   40



                  (d) In the event that there shall not be sufficient shares of
Common Stock of the Company or Preferred Stock (or Preferred Stock Equivalents)
issued but not outstanding or authorized but unissued to permit any exchange of
Rights as contemplated in accordance with this Section 24, the Company shall
take all such action as may be necessary to authorize additional shares of
Common Stock of the Company or Preferred Stock (or Preferred Stock Equivalent)
for issuance upon exchange of the Rights.

                  (e) The Company shall not be required to issue fractions of
Common Stock of the Company or to distribute certificates which evidence
fractional shares of Common Stock of the Company. If the Company elects not to
issue such fractional shares of Common Stock of the Company, the Company shall
pay, in lieu of such fractional shares of Common Stock of the Company, to the
registered holders of the Right Certificates with regard to which such
fractional shares of Common Stock of the Company would otherwise be issuable, an
amount in cash equal to the same fraction of the Fair Market Value of a whole
share of Common Stock of the Company. For the purposes of this paragraph (e),
the Fair Market Value of a whole share of Common Stock of the Company shall be
the closing price of a share of Common Stock of the Company (as determined
pursuant to the second sentence of Section 11(d)(i) hereof) for the Trading Day
immediately prior to the date of exchange pursuant to this Section 24.

         Section 25.  NOTICE OF CERTAIN EVENTS.

                  (a) In case the Company shall propose, at any time after the
Distribution Date, (i) to pay any dividend payable in stock of any class to the
holders of Preferred Stock or to make any other distribution to the holders of
Preferred Stock (other than a regular periodic cash dividend out of earnings or
retained earnings of the Company), or (ii) to offer to the holders of Preferred
Stock rights or warrants to subscribe for or to purchase any additional shares
of Preferred Stock or shares of stock of any class or any other securities,
rights or options, or (iii) to effect any reclassification of its Preferred
Stock (other than a reclassification involving only the subdivision of
outstanding shares of Preferred Stock), or (iv) to effect any consolidation or
merger into or with, or to effect any sale, mortgage or other transfer (or to
permit one or more of its Subsidiaries to effect any sale, mortgage or other
transfer), in one transaction or a series of related transactions, of 50% or
more of the assets or earning power of the Company and its Subsidiaries (taken
as a whole) to, any other Person (other than a Subsidiary of the Company in one
or more transactions each of which is not prohibited by the proviso at the end
of the first sentence of Section 11(n) hereof), (v) to effect the liquidation,
dissolution or winding up of the Company, or (vi) to declare or pay any dividend
on the Common Stock of the Company payable in Common Stock of the Company or to
effect a subdivision, combination or consolidation of the Common Stock of the
Company (by reclassification or otherwise than by payment of dividends in Common
Stock of the Company) then in each such case, the Company shall give to each
holder of a Right Certificate and to the Rights Agent, in accordance with
Section 26 hereof, a notice of such proposed action, which shall specify the
record date for the purposes of such stock dividend, distribution of rights or
warrants, or the date on which such reclassification, consolidation, merger,
sale, transfer, liquidation, dissolution, or winding up is to take place and the
date of participation therein by

                                       37

<PAGE>   41



the holders of the shares of Common Stock of the Company and/or Preferred Stock,
if any such date is to be fixed, and such notice shall be so given in the case
of any action covered by clause (i) or (ii) above at least twenty (20) days
prior to the record date for determining holders of the shares of Preferred
Stock for purposes of such action, and in the case of any such other action, at
least twenty (20) days prior to the date of the taking of such proposed action
or the date of participation therein by the holders of the shares of Common
Stock of the Company and/or Preferred Stock, whichever shall be the earlier;
PROVIDED, HOWEVER, no such notice shall be required pursuant to this Section 25
as a result of any Subsidiary of the Company effecting a consolidation or merger
with or into, or effecting a sale or other transfer of assets or earnings power
to, any other Subsidiary of the Company in a manner not inconsistent with the
provisions of this Agreement.

                  (b) In case any Section 11(a)(ii) Event shall occur, then, in
any such case, the Company shall as soon as practicable thereafter give to each
registered holder of a Right Certificate and to the Rights Agent, in accordance
with Section 26 hereof, a notice of the occurrence of such event, which shall
specify the event and the consequences of the event to holders of Rights under
Section 11(a)(ii) hereof.

         Section 26. NOTICES. Notices or demands authorized by this Agreement to
be given or made by the Rights Agent or by the holder of any Right Certificate
to or on the Company shall be sufficiently given or made if sent by first-class
mail, postage prepaid, by facsimile transmission or by nationally-recognized
overnight courier addressed (until another address is filed in writing with the
Rights Agent) as follows:

                  MASSBANK Corp.
                  123 Haven Street
                  Reading, MA 01867
                  Attention:  Secretary

Subject to the provisions of Section 21, any notice or demand authorized by this
Agreement to be given or made by the Company or by the holder of any Right
Certificate to or on the Rights Agent shall be sufficiently given or made if
sent by first-class mail, postage prepaid, by facsimile transmission or by
nationally-recognized overnight courier addressed (until another address is
filed in writing with the Company) as follows:

                  BankBoston, N.A.
                  c/o EquiServe Limited Partnership
                  150 Royall Street
                  Canton, MA 02021
                  Attention: Administration

Notices or demands authorized by this Agreement to be given or made by the
Company or the Rights Agent to the holder of any Right Certificate (or, prior to
the Distribution Date, to the holder of any certificate representing shares of
Common Stock of the Company) shall be

                                       38

<PAGE>   42



sufficiently given or made if sent by first-class mail, postage prepaid,
addressed to such holder at the address of such holder as shown on the registry
books of the Company.

         Section 27. SUPPLEMENTS AND AMENDMENTS. Prior to the occurrence of a
Section 11(a)(ii) Event, the Company and the Rights Agent shall, if the Board of
Directors of the Company so directs, supplement or amend any provision of this
Agreement as the Board of Directors of the Company may deem necessary or
desirable without the approval of any holders of certificates representing
shares of Common Stock of the Company. From and after the occurrence of a
Section 11(a)(ii) Event, the Company and the Rights Agent shall, if the Board of
Directors of the Company so directs, supplement or amend this Agreement without
the approval of any holder of Right Certificates in order (i) to cure any
ambiguity, (ii) to correct or supplement any provision contained herein which
may be defective or inconsistent with any other provisions herein, (iii) to
shorten or lengthen any time period hereunder, or (iv) to change or supplement
the provisions hereof in any manner which the Board of Directors of the Company
may deem necessary or desirable and which shall not adversely affect the
interests of the holders of Right Certificates (other than an Acquiring Person
or any Affiliate or Associate of an Acquiring Person); PROVIDED, HOWEVER, that
from and after the occurrence of a Section 11(a)(ii) Event this Agreement may
not be supplemented or amended to lengthen, pursuant to clause (iii) of this
sentence, (A) a time period relating to when the Rights may be redeemed at such
time as the Rights are not then redeemable or (B) any other time period unless
such lengthening is for the purpose of protecting, enhancing or clarifying the
rights of, and the benefits to, the holders of Rights (other than an Acquiring
Person or any Affiliate or Associate of an Acquiring Person). Upon the delivery
of such certificate from an appropriate officer of the Company which states that
the proposed supplement or amendment is in compliance with the terms of this
Section 27, the Rights Agent shall execute such supplement or amendment. Prior
to the occurrence of a Section 11(a)(ii) Event, the interests of the holders of
Rights shall be deemed coincident with the interests of the holders of Common
Stock of the Company. Notwithstanding any other provision hereof, the Rights
Agent's consent must be obtained regarding any amendment or supplement pursuant
to this Section 27 which alters the Rights Agent's rights or duties.

         Section 28. SUCCESSORS. All the covenants and provisions of this
Agreement by or for the benefit of the Company or the Rights Agent shall bind
and inure to the benefit of their respective successors and assigns hereunder.

         Section 29. DETERMINATIONS AND ACTIONS BY THE BOARD OF DIRECTORS. The
Board of Directors of the Company shall have the exclusive power and authority
to administer this Agreement and to exercise all rights and powers specifically
granted to the Board of Directors or to the Company, or as may be necessary or
advisable in the administration of this Agreement, including without limitation,
the right and power to (i) interpret the provisions of this Agreement and (ii)
make all determinations deemed necessary or advisable for the administration of
this Agreement (including a determination to redeem or not redeem the Rights or
to amend the Agreement). All such actions, calculations, interpretations and
determinations (including, for purposes of clause (y) below, all omissions with
respect to the

                                       39

<PAGE>   43



foregoing) which are done or made by the Board of Directors in good faith shall
(x) be final, conclusive and binding on the Company, the Rights Agent, the
holders of the Rights and all other parties, and (y) not subject any member of
the Board of Directors to any liability to the holders of the Rights or to any
other person.

         Section 30. BENEFITS OF THIS AGREEMENT. Nothing in this Agreement shall
be construed to give to any person or corporation other than the Company, the
Rights Agent and the registered holders of the Right Certificates (and, prior to
the Distribution Date, the Common Stock of the Company) any legal or equitable
right, remedy or claim under this Agreement; but this Agreement shall be for the
sole and exclusive benefit of the Company, the Rights Agent and the registered
holders of the Right Certificates (and, prior to the Distribution Date,
registered holders of the Common Stock of the Company).

         Section 31. SEVERABILITY. If any term, provision, covenant or
restriction of this Agreement is held by a court of competent jurisdiction or
other authority to be invalid, void or unenforceable, the remainder of the
terms, provisions, covenants and restrictions of this Agreement shall remain in
full force and effect and shall in no way be affected, impaired or invalidated;
PROVIDED, HOWEVER, that notwithstanding anything in this Agreement to the
contrary, if any such term, provision, covenant or restriction is held by such
court or authority to be invalid, void or unenforceable and the Board of
Directors of the Company determines in its good faith judgment that severing the
invalid language from the Agreement would adversely affect the purpose or effect
of the Agreement, the right of redemption set forth in Section 23 hereof shall
be reinstated and shall not expire until the Close of Business on the tenth day
following the date of such determination by the Board of Directors.

         Section 32. GOVERNING LAW. This Agreement, each Right and each Right
Certificate issued hereunder shall be deemed to be a contract made under the
laws of the State of Delaware and for all purposes shall be governed by and
construed in accordance with the laws of such State applicable to contracts to
be made and to be performed entirely within such State. The courts of the State
of Delaware and of the United States of America located in the State of Delaware
(the "Delaware Courts") shall have exclusive jurisdiction over any litigation
arising out of or relating to this Agreement and the transactions contemplated
hereby, and any Person commencing or otherwise involved in any such litigation
shall waive any objection to the laying of venue of such litigation in the
Delaware Courts and shall not plead or claim in any Delaware Court that such
litigation brought therein has been brought in an inconvenient forum.

         Section 33. COUNTERPARTS. This Agreement may be executed in any number
of counterparts and each of such counterparts shall for all purposes be deemed
to be an original, and all such counterparts shall together constitute but one
and the same instrument.

         Section 34. DESCRIPTIVE HEADINGS. Descriptive headings of the several
Sections of this Agreement are inserted for convenience only and shall not
control or affect the meaning or construction of any of the provisions hereof.


                                       40

<PAGE>   44




         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed as an instrument under seal and attested, all as of the day and
year first above written.


ATTEST:                                 MASSBANK CORP.



By: /s/ Reginald E. Cormier             By: /s/ Gerard H. Brandi
    ---------------------------------       ---------------------------------
                                            Name: Gerard H. Brandi
                                            Title: Chairman, President and CEO



ATTEST:                                 BANKBOSTON, N.A., as Rights Agent



By: /s/ Sandra Burgess                  By: /s/ Katherine Anderson
    ---------------------------------       ---------------------------------
                                            Name: Katherine Anderson
                                            Title: Director, Client Services




<PAGE>   45



                                                                       EXHIBIT A




                         VOTE OF DIRECTORS ESTABLISHING
                    SERIES B JUNIOR PARTICIPATING CUMULATIVE
                                 PREFERRED STOCK

                                       of

                                 MASSBANK CORP.

         Pursuant to Section 151 of the General Corporation Law of the State of
Delaware:

         VOTED, that pursuant to authority conferred upon and vested in the
Board of Directors by the Restated Certificate of Incorporation, as amended (the
"Certificate of Incorporation"), of MASSBANK Corp. (the "Corporation"), the
Board of Directors hereby establishes and designates a series of Preferred Stock
of the Corporation, and hereby fixes and determines the relative rights and
preferences of the shares of such series, in addition to those set forth in the
Certificate of Incorporation, as follows:

         Section 1. DESIGNATION AND AMOUNT. The shares of such series shall be
designated as "Series B Junior Participating Cumulative Preferred Stock" (the
"Series B Preferred Stock"), and the number of shares initially constituting
such series shall be 60,000; provided, however, that if more than a total of
60,000 shares of Series B Preferred Stock shall be issuable upon the exercise of
Rights (the "Rights") issued pursuant to the Shareholder Rights Agreement dated
as of January 18, 2000, between the Corporation and BankBoston, N.A., as Rights
Agent (the "Rights Agreement"), the Board of Directors of the Corporation,
pursuant to Section 151(g) of the General Corporation Law of the State of
Delaware, may direct by resolution or resolutions that a certificate be properly
executed, acknowledged, filed and recorded, in accordance with the provisions of
Section 103 thereof, providing for the total number of shares of Series B
Preferred Stock authorized to be issued to be increased (to the extent that the
Certificate of Incorporation then permits) to the largest number of whole shares
(rounded up to the nearest whole number) issuable upon exercise of such Rights.

         Section 2.  DIVIDENDS AND DISTRIBUTIONS.

         (A) (i) Subject to the rights of the holders of any shares of any
series of preferred stock (or any similar stock) ranking prior and superior to
the Series B Preferred Stock with respect to dividends, the holders of shares of
Series B Preferred Stock, in preference to the holders of shares of common stock
and of any other junior stock, shall be entitled to receive, when, as and if
declared by the Board of Directors out of funds legally available for the
purpose, quarterly dividends payable in cash on the first day of March, June,
September and December in each year (each such date being referred to herein as
a "Quarterly Dividend Payment Date"), commencing on the first Quarterly Dividend
Payment Date after the first issuance of a share or fraction of a


<PAGE>   46



share of Series B Preferred Stock, in an amount per share (rounded to the
nearest cent) equal to the greater of (a) $1.00 or (b) subject to the provisions
for adjustment hereinafter set forth, 1,000 times the aggregate per share amount
of all cash dividends, and 1,000 times the aggregate per share amount (payable
in kind) of all non-cash dividends or other distributions other than a dividend
payable in shares of common stock or a subdivision of the outstanding shares of
common stock (by reclassification or otherwise), declared on the common stock
since the immediately preceding Quarterly Dividend Payment Date, or, with
respect to the first Quarterly Dividend Payment Date, since the first issuance
of any share or fraction of a share of Series B Preferred Stock. The multiple of
cash and non-cash dividends declared on the common stock to which holders of the
Series B Preferred Stock are entitled, which shall be 1,000 initially but which
shall be adjusted from time to time as hereinafter provided, is hereinafter
referred to as the "Dividend Multiple." In the event the Corporation shall at
any time after January 18, 2000 (the "Rights Declaration Date") (i) declare or
pay any dividend on common stock payable in shares of common stock, or (ii)
effect a subdivision or combination or consolidation of the outstanding shares
of common stock (by reclassification or otherwise than by payment of a dividend
in shares of common stock) into a greater or lesser number of shares of common
stock, then in each such case the Dividend Multiple thereafter applicable to the
determination of the amount of dividends which holders of shares of Series B
Preferred Stock shall be entitled to receive shall be the Dividend Multiple
applicable immediately prior to such event multiplied by a fraction, the
numerator of which is the number of shares of common stock outstanding
immediately after such event and the denominator of which is the number of
shares of common stock that were outstanding immediately prior to such event.

             (ii) Notwithstanding anything else contained in this paragraph (A),
the Corporation shall, out of funds legally available for that purpose, declare
a dividend or distribution on the Series B Preferred Stock as provided in this
paragraph (A) immediately after it declares a dividend or distribution on the
common stock (other than a dividend payable in shares of common stock); provided
that, in the event no dividend or distribution shall have been declared on the
common stock during the period between any Quarterly Dividend Payment Date and
the next subsequent Quarterly Dividend Payment Date, a dividend of $1.00 per
share on the Series B Preferred Stock shall nevertheless be payable on such
subsequent Quarterly Dividend Payment Date.

         (B) Dividends shall begin to accrue and be cumulative on outstanding
shares of Series B Preferred Stock from the Quarterly Dividend Payment Date next
preceding the date of issue of such shares of Series B Preferred Stock, unless
the date of issue of such shares is prior to the record date for the first
Quarterly Dividend Payment Date, in which case dividends on such shares shall
begin to accrue from the date of issue of such shares, or unless the date of
issue is a Quarterly Dividend Payment Date or is a date after the record date
for the determination of holders of shares of Series B Preferred Stock entitled
to receive a quarterly dividend and before such Quarterly Dividend Payment Date,
in either of which events such dividends shall begin to accrue and be cumulative
from such Quarterly Dividend Payment Date. Accrued but unpaid dividends shall
not bear interest. Dividends paid on the shares of Series B Preferred Stock in
an amount less than the total amount of such dividends at the time accrued and
payable on such shares shall be allocated pro rata on a share-by-share basis
among all such shares at the time outstanding. The

                                       A-2

<PAGE>   47



Board of Directors may fix in accordance with applicable law a record date for
the determination of holders of shares of Series B Preferred Stock entitled to
receive payment of a dividend or distribution declared thereon, which record
date shall be not more than such number of days prior to the date fixed for the
payment thereof as may be allowed by applicable law.

         Section 3. VOTING RIGHTS. In addition to any other voting rights
required by law, the holders of shares of Series B Preferred Stock shall have
the following voting rights:

         (A) Subject to the provision for adjustment hereinafter set forth, each
share of Series B Preferred Stock shall entitle the holder thereof to 1,000
votes on all matters submitted to a vote of the shareholders of the Corporation.
The number of votes which a holder of a share of Series B Preferred Stock is
entitled to cast, which shall initially be 1,000 but which may be adjusted from
time to time as hereinafter provided, is hereinafter referred to as the "Vote
Multiple." In the event the Corporation shall at any time after the Rights
Declaration Date (i) declare or pay any dividend on common stock payable in
shares of common stock, or (ii) effect a subdivision or combination or
consolidation of the outstanding shares of common stock (by reclassification or
otherwise than by payment of a dividend in shares of common stock) into a
greater or lesser number of shares of common stock, then in each such case the
Vote Multiple thereafter applicable to the determination of the number of votes
per share to which holders of shares of Series B Preferred Stock shall be
entitled shall be the Vote Multiple immediately prior to such event multiplied
by a fraction, the numerator of which is the number of shares of common stock
outstanding immediately after such event and the denominator of which is the
number of shares of common stock that were outstanding immediately prior to such
event.

         (B) Except as otherwise provided herein or by law, the holders of
shares of Series B Preferred Stock and the holders of shares of common stock and
the holders of shares of any other capital stock of this Corporation having
general voting rights, shall vote together as one class on all matters submitted
to a vote of shareholders of the Corporation.

         (C) Except as otherwise required by applicable law or as set forth
herein, holders of Series B Preferred Stock shall have no special voting rights
and their consent shall not be required (except to the extent they are entitled
to vote with holders of common stock as set forth herein) for taking any
corporate action.


         Section 4.  CERTAIN RESTRICTIONS.

         (A) Whenever dividends or distributions payable on the Series B
Preferred Stock as provided in Section 2 are in arrears, thereafter and until
all accrued and unpaid dividends and distributions, whether or not declared, on
shares of Series B Preferred Stock outstanding shall have been paid in full, the
Corporation shall not:

         (i)      declare or pay dividends on, make any other distributions on,
                  or redeem or purchase or otherwise acquire for consideration
                  any shares of stock ranking junior

                                       A-3

<PAGE>   48



                  (either as to dividends or upon liquidation, dissolution or
                  winding up) to the Series B Preferred Stock;

         (ii)     declare or pay dividends on or make any other distributions on
                  any shares of stock ranking on a parity (either as to
                  dividends or upon liquidation, dissolution or winding up) with
                  the Series B Preferred Stock, except dividends paid ratably on
                  the Series B Preferred Stock and all such parity stock on
                  which dividends are payable or in arrears in proportion to the
                  total amounts to which the holders of all such shares are then
                  entitled;

         (iii)    except as permitted in subsection 4(A)(iv) below, redeem,
                  purchase or otherwise acquire for consideration shares of any
                  stock ranking on a parity (either as to dividends or upon
                  liquidation, dissolution or winding up) with the Series B
                  Preferred Stock, provided that the Corporation may at any time
                  redeem, purchase or otherwise acquire shares of any such
                  parity stock in exchange for shares of any stock of the
                  Corporation ranking junior (either as to dividends or upon
                  dissolution, liquidation or winding up) to the Series B
                  Preferred Stock; or

         (iv)     purchase or otherwise acquire for consideration any shares of
                  Series B Preferred Stock, or any shares of any stock ranking
                  on a parity (either as to dividends or upon liquidation,
                  dissolution or winding up) with the Series B Preferred Stock,
                  except in accordance with a purchase offer made in writing or
                  by publication (as determined by the Board of Directors) to
                  all holders of such shares upon such terms as the Board of
                  Directors, after consideration of the respective annual
                  dividend rates and other relative rights and preferences of
                  the respective series and classes, shall determine in good
                  faith will result in fair and equitable treatment among the
                  respective series or classes.

         (B) The Corporation shall not permit any subsidiary of the Corporation
to purchase or otherwise acquire for consideration any shares of stock of the
Corporation unless the Corporation could, under subsection (A) of this Section
4, purchase or otherwise acquire such shares at such time and in such manner.

         Section 5. REACQUIRED SHARES. Any shares of Series B Preferred Stock
purchased or otherwise acquired by the Corporation in any manner whatsoever
shall be retired and canceled promptly after the acquisition thereof. All such
shares shall upon their cancellation become authorized but unissued shares of
preferred stock and may be reissued as part of a new series of preferred stock
to be created by resolution or resolutions of the Board of Directors, subject to
the conditions and restrictions on issuance set forth herein.

         Section 6. LIQUIDATION, DISSOLUTION OR WINDING UP. Upon any liquidation
(voluntary or otherwise), dissolution or winding up of the Corporation, no
distribution shall be made (x) to the holders of shares of stock ranking junior
(either as to dividends or upon liquidation, dissolution or winding up) to the
Series B Preferred Stock unless, prior thereto, the holders of shares of Series

                                       A-4

<PAGE>   49



B Preferred Stock shall have received an amount equal to accrued and unpaid
dividends and distributions thereon, whether or not declared, to the date of
such payment, plus an amount equal to the greater of (1) $1,000.00 per share or
(2) an aggregate amount per share, subject to the provision for adjustment
hereinafter set forth, equal to 1,000 times the aggregate amount to be
distributed per share to holders of common stock, or (y) to the holders of stock
ranking on a parity (either as to dividends or upon liquidation, dissolution or
winding up) with the Series B Preferred Stock, except distributions made ratably
on the Series B Preferred Stock and all other such parity stock in proportion to
the total amounts to which the holders of all such shares are entitled upon such
liquidation, dissolution or winding up. In the event the Corporation shall at
any time after the Rights Declaration Date (i) declare or pay any dividend on
common stock payable in shares of common stock, or (ii) effect a subdivision or
combination or consolidation of the outstanding shares of common stock (by
reclassification or otherwise than by payment of a dividend in shares of common
stock) into a greater or lesser number of shares of common stock, then in each
such case the aggregate amount per share to which holders of shares of Series B
Preferred Stock were entitled immediately prior to such event under clause (x)
of the preceding sentence shall be adjusted by multiplying such amount by a
fraction, the numerator of which is the number of shares of common stock
outstanding immediately after such event and the denominator of which is the
number of shares of common stock that were outstanding immediately prior to such
event.

         Neither the consolidation of nor merging of the Corporation with or
into any other corporation or corporations, nor the sale or other transfer of
all or substantially all of the assets of the Corporation, shall be deemed to be
a liquidation, dissolution or winding up of the Corporation within the meaning
of this Section 6.

         Section 7. CONSOLIDATION, MERGER, ETC. In case the Corporation shall
enter into any consolidation, merger, combination or other transaction in which
the shares of common stock are exchanged for or changed into other stock or
securities, cash and/or any other property, then in any such case the shares of
Series B Preferred Stock shall at the same time be similarly exchanged or
changed in an amount per share (subject to the provision for adjustment
hereinafter set forth) equal to 1,000 times the aggregate amount of stock,
securities, cash and/or any other property (payable in kind), as the case may
be, into which or for which each share of common stock is changed or exchanged,
plus accrued and unpaid dividends, if any, payable with respect to the Series B
Preferred Stock. In the event the Corporation shall at any time after the Rights
Declaration Date (i) declare or pay any dividend on common stock payable in
shares of common stock, or (ii) effect a subdivision or combination or
consolidation of the outstanding shares of common stock (by reclassification or
otherwise than by payment of a dividend in shares of common stock) into a
greater or lesser number of shares of common stock, then in each such case the
amount set forth in the preceding sentence with respect to the exchange or
change of shares of Series B Preferred Stock shall be adjusted by multiplying
such amount by a fraction, the numerator of which is the number of shares of
common stock outstanding immediately after such event and the denominator of
which is the number of shares of common stock that were outstanding immediately
prior to such event.


                                       A-5

<PAGE>   50



         Section 8. REDEMPTION. The shares of Series B Preferred Stock shall not
be redeemable; provided, however, that the foregoing shall not limit the ability
of the Corporation to purchase or otherwise deal in such shares to the extent
otherwise permitted hereby and by law.

         Section 9. RANKING. Unless otherwise expressly provided in the
Certificate of Incorporation or a Certificate of Designations relating to any
other series of preferred stock of the Corporation, the Series B Preferred Stock
shall rank junior to every other series of the Corporation's preferred stock
previously or hereafter authorized, as to the payment of dividends and the
distribution of assets on liquidation, dissolution or winding up and shall rank
senior to the common stock.

         Section 10. AMENDMENT. The Certificate of Incorporation and this
Certificate of Designations shall not be amended in any manner which would
materially alter or change the powers, preferences or special rights of the
Series B Preferred Stock so as to affect them adversely without the affirmative
vote of the holders of two-thirds or more of the outstanding shares of Series B
Preferred Stock, voting separately as a class.

         Section 11. FRACTIONAL SHARES. Series B Preferred Stock may be issued
in whole shares or in any fraction of a share that is one one-thousandth
(1/1,000th) of a share or any integral multiple of such fraction, which shall
entitle the holder, in proportion to such holder's fractional shares, to
exercise voting rights, receive dividends, participate in distributions and to
have the benefit of all other rights of holders of Series B Preferred Stock. In
lieu of fractional shares, the Corporation may elect to make a cash payment as
provided in the Rights Agreement for fractions of a share other than one
one-thousandth (1/1,000th) of a share or any integral multiple thereof.



                                       A-6

<PAGE>   51




                                                                       EXHIBIT B


                           [Form of Right Certificate]


Certificate No. R-                                                 ______ Rights


NOT EXERCISABLE AFTER JANUARY 19, 2010 OR EARLIER IF NOTICE OF REDEMPTION IS
GIVEN. THE RIGHTS ARE SUBJECT TO REDEMPTION, AT THE OPTION OF MASSBANK CORP., AT
$0.01 PER RIGHT ON THE TERMS SET FORTH IN THE SHAREHOLDER RIGHTS AGREEMENT
BETWEEN MASSBANK CORP. AND BANKBOSTON, N.A., AS RIGHTS AGENT, DATED AS OF
JANUARY 18, 2000 (THE "RIGHTS AGREEMENT"). AS SPECIFIED IN SECTION 7(e) OF THE
RIGHTS AGREEMENT, RIGHTS BENEFICIALLY OWNED BY AN ACQUIRING PERSON OR AN
ASSOCIATE OR AFFILIATE OF AN ACQUIRING PERSON (AS SUCH TERMS ARE DEFINED IN THE
RIGHTS AGREEMENT) AND ANY SUBSEQUENT HOLDER OF SUCH RIGHTS BECOME NULL AND VOID.


Right Certificate

MASSBANK CORP.


This certifies that _______________________, or registered assigns, is the
registered owner of the number of Rights set forth above, each of which entitles
the owner thereof, subject to the terms, provisions and conditions of the
Shareholder Rights Agreement dated as of January 18, 2000 (the "Rights
Agreement") between MASSBANK Corp. (the "Company") and BankBoston, N.A., as
Rights Agent (the "Rights Agent"), to purchase from the Company at any time
after the Distribution Date (as such term is defined in the Rights Agreement)
and prior to the close of business on January 19, 2010 at the office or offices
of the Rights Agent designated for such purpose, or its successors as Rights
Agent, one one-thousandth of a fully paid, non-assessable share of the Series B
Junior Participating Cumulative Preferred Stock (the "Preferred Stock") of the
Company, at a purchase price of _____ per one one-thousandth of a share (the
"Exercise Price"), upon presentation and surrender of this Right Certificate
with the Form of Election to Purchase and the related Certificate duly executed.
The number of Rights evidenced by this Right Certificate (and the number of
shares which may be purchased upon exercise thereof) set forth above, and the
Exercise Price per share set forth above, are the number and Exercise Price as
of ______________, based on the Preferred Stock as constituted at such date.


                                       B-1

<PAGE>   52



         Upon the occurrence of a Section 11(a)(ii) Event (as such term is
defined in the Rights Agreement), if the Rights evidenced by this Right
Certificate are beneficially owned by (i) an Acquiring Person or an Affiliate or
Associate of any such Person (as such terms are defined in the Rights
Agreement), (ii) a transferee of any such Acquiring Person, Associate or
Affiliate, or (iii) under certain circumstances specified in the Rights
Agreement, a transferee of a Person who, after such transfer, became an
Acquiring Person, or an Affiliate or Associate of an Acquiring Person, such
Rights shall become null and void and no holder hereof shall have any right with
respect to such Rights from and after the occurrence of such Section 11(a)(ii)
Event.

         As provided in the Rights Agreement, the Exercise Price and the number
of shares of Preferred Stock or other securities which may be purchased upon the
exercise of the Rights evidenced by this Right Certificate are subject to
modification and adjustment upon the happening of certain events.

         This Right Certificate is subject to all of the terms, provisions and
conditions of the Rights Agreement, which terms, provisions and conditions are
hereby incorporated herein by reference and made a part hereof and to which
Rights Agreement reference is hereby made for a full description of the rights,
limitations of rights, obligations, duties and immunities hereunder of the
Rights Agent, the Company and the holders of the Right Certificates, which
limitations of rights include the temporary suspension of the exercisability of
such Rights under the specific circumstances set forth in the Rights Agreement.
Copies of the Rights Agreement are on file at the principal office of the
Company and the designated office of the Rights Agent and are also available
upon written request to the Company or the Rights Agent.

         This Right Certificate, with or without other Right Certificates, upon
surrender at the office or offices of the Rights Agent designated for such
purpose, may be exchanged for another Right Certificate or Certificates of like
tenor and date evidencing Rights entitling the holder to purchase a like
aggregate number of shares of Preferred Stock as the Rights evidenced by the
Right Certificate or Certificates surrendered shall have entitled such holder to
purchase. If this Right Certificate shall be exercised in part, the holder shall
be entitled to receive upon surrender hereof another Right Certificate or
Certificates for the number of whole Rights not exercised. If this Right
Certificate shall be exercised in whole or in part pursuant to Section 11(a)(ii)
of the Rights Agreement, the holder shall be entitled to receive this Right
Certificate duly marked to indicate that such exercise has occurred as set forth
in the Rights Agreement.

         Under certain circumstances, subject to the provisions of the Rights
Agreement, the Board of Directors of the Company at its option may exchange all
or any part of the Rights evidenced by this Certificate for shares of the
Company's Common Stock or Preferred Stock at an exchange ratio (subject to
adjustment) specified in the Rights Agreement.

         Subject to the provisions of the Rights Agreement, the Rights evidenced
by this Certificate may be redeemed by the Board of Directors of the Company at
its option at a

                                       B-2

<PAGE>   53



redemption price of $0.01 per Right (payable in cash, Common Stock or other
consideration deemed appropriate by the Board of Directors).

         The Company is not obligated to issue fractional shares of stock upon
the exercise of any Right or Rights evidenced hereby (other than fractions which
are integral multiples of one one-thousandth of a share of Preferred Stock,
which may, at the election of the Company, be evidenced by depositary receipts).
If the Company elects not to issue such fractional shares, in lieu thereof a
cash payment will be made, as provided in the Rights Agreement.

         No holder of this Right Certificate, as such, shall be entitled to vote
or receive dividends or be deemed for any purpose the holder of shares of
Preferred Stock, Common Stock or any other securities of the Company which may
at any time be issuable on the exercise hereof, nor shall anything contained in
the Rights Agreement or herein be construed to confer upon the holder hereof, as
such, any of the rights of a shareholder of the Company or any right to vote for
the election of directors or upon any matter submitted to shareholders at any
meeting thereof, or to give or withhold consent to any corporate action, or to
receive notice of meetings or other actions affecting shareholders (except as
provided in the Rights Agreement), or to receive dividends or subscription
rights, or otherwise, until the Right or Rights evidenced by this Right
Certificate shall have been exercised as provided in the Rights Agreement.

         This Right Certificate shall not be valid or obligatory for any purpose
until it shall have been countersigned by an authorized signatory of the Rights
Agent.

         WITNESS the facsimile signature of the proper officers of the Company
as a document under seal.

Attested:                               MASSBANK Corp.

By:__________________________________   By: _______________________________
   [Secretary or Assistant Secretary]       Name:
                                            Title: [Chairman, Vice Chairman,
                                                    President or Vice President]

Countersigned:

[RIGHTS AGENT]

By:_________________________________
   Name:
   Title:



                                       B-3

<PAGE>   54



                   [Form of Reverse Side of Right Certificate]

                               FORM OF ASSIGNMENT
                               ------------------

                (To be executed by the registered holder if such
               holder desires to transfer the Right Certificate.)


FOR VALUE RECEIVED ___________________________ hereby sells, assigns and
transfers unto ____________________________________ (Please print name and
address of transferee) ____________________________________ this Right
Certificate, together with all right, title and interest therein, and does
hereby irrevocably constitute and appoint ___________________ Attorney, to
transfer the within Right Certificate on the books of the within-named Company,
with full power of substitution.


Dated: ______________, _____            ___________________________________
                                        Signature

Signature Guaranteed: _______________________


                                   CERTIFICATE
                                   -----------


         The undersigned hereby certifies by checking the appropriate boxes
that:

         (1) the Rights evidenced by this Right Certificate ______ are ______
are not being transferred by or on behalf of a Person who is or was an Acquiring
Person or an Affiliate or Associate of any such Person (as such terms are
defined in the Rights Agreement); and

         (2) after due inquiry and to the best knowledge of the undersigned, the
undersigned ______ did ______ did not directly or indirectly acquire the Rights
evidenced by this Right Certificate from any Person who is, was or became an
Acquiring Person or an Affiliate or Associate of any such Person.


Dated: ______________, _____            ___________________________________
                                        Signature


                                       B-4

<PAGE>   55



                                     NOTICE
                                     ------


         The signature to the foregoing Assignment and Certificate must

correspond to the name as written upon the face of this Right Certificate in

every particular, without alteration or enlargement or any change whatsoever.



                                       B-5

<PAGE>   56



                          FORM OF ELECTION TO PURCHASE
                          ----------------------------

                      (To be executed if holder desires to
                        exercise the Right Certificate.)


To MASSBANK CORP.:

         The undersigned hereby irrevocably elects to exercise _______ Rights
represented by this Right Certificate to purchase the shares of Preferred Stock
issuable upon the exercise of the Rights (or such other securities of the
Company or of any other person which may be issuable upon the exercise of the
Rights) and requests that certificates for such shares be issued in the name of:

Please insert social security
or other identifying taxpayer number:  __________________


________________________________________________________________________________
                         (Please print name and address)


________________________________________________________________________________

________________________________________________________________________________

         If such number of Rights shall not be all the Rights evidenced by this
Right Certificate or if the Rights are being exercised pursuant to Section
11(a)(ii) of the Rights Agreement, a new Right Certificate for the balance of
such Rights shall be registered in the name of and delivered to:

Please insert social security
or other identifying taxpayer number:  _____________________


________________________________________________________________________________
                         (Please print name and address)


________________________________________________________________________________

________________________________________________________________________________


Dated: ______________, _____            ___________________________________
                                        Signature

Signature Guaranteed: _______________________



                                       B-6

<PAGE>   57



                                   CERTIFICATE
                                   -----------


         The undersigned hereby certifies by checking the appropriate boxes
that:

         (1) the Rights evidenced by this Right Certificate ____ are ____ are
not being exercised by or on behalf of a Person who is or was an Acquiring
Person or an Affiliate or Associate of any such Person (as such terms are
defined in the Rights Agreement); and

         (2) after due inquiry and to the best knowledge of the undersigned, the
undersigned ____ did ____ did not directly or indirectly acquire the Rights
evidenced by this Right Certificate from any Person who is, was or became an
Acquiring Person or an Affiliate or Associate of any such Person.


Dated: ______________, _____            ___________________________________
                                        Signature



                                       B-7

<PAGE>   58


                                     NOTICE
                                     ------

         The signature to the foregoing Election to Purchase and Certificate

must correspond to the name as written upon the face of this Right Certificate

in every particular, without alteration or enlargement or any change whatsoever.