<PAGE>
                                                                     Exhibit 4.1

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                              T CELL SCIENCES, INC.

                                       and

                      STATE STREET BANK AND TRUST COMPANY,

                                 as Rights Agent

                                   ----------

                          Shareholder Rights Agreement

                          Dated as of November 10, 1994

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                                TABLE OF CONTENTS
Section                                                                    Page
-------                                                                    ----

1.   Certain Definitions ................................................... 1
2.   Appointment of Rights Agent ........................................... 5
3.   Issue of Right Certificates ........................................... 5
4.   Form of Right Certificates ............................................ 7
5.   Countersignature and Registration ..................................... 8
6.   Transfer, Split Up, Combination and Exchange of Right Certificates;
     Mutilated, Destroyed, Lost or Stolen Right Certificates ............... 9
7.   Exercise of Rights; Exercise Price; Expiration Date of Rights ......... 9
8.   Cancellation and Destruction of Right Certificates ....................11
9.   Reservation and Availability of Preferred Stock .......................12
10.  Preferred Stock Record Date ...........................................13
11.  Adjustment of Exercise Price, Number and Kind of Shares or
     Number of Rights ......................................................13
12.  Certificate of Adjusted Exercise Price or Number of Shares ............21
13.  Consolidation, Merger or Sale or Transfer of Assets or Earning Power ..21
14.  Fractional Rights and Fractional Shares ...............................24
15.  Rights of Action ......................................................24
16.  Agreement of Right Holders ............................................25
17.  Right Certificate Holder Not Deemed a Shareholder .....................25
18.  Concerning the Rights Agent ...........................................26
19.  Merger or Consolidation or Change of Name of Rights Agent .............26
20.  Duties of Rights Agent ................................................27


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<PAGE>

21.  Change of Rights Agent ................................................29
22.  Issuance of New Right Certificates ....................................30
23.  Redemption and Termination ............................................31
24.  Exchange ..............................................................31
25.  Notice of Certain Events ..............................................33
26.  Notices ...............................................................34
27.  Supplements and Amendments ............................................34
28.  Successors ............................................................35
29.  Determinations and Actions by the Board of Directors ..................35
30.  Benefits of this Agreement ............................................35
31.  Severability ..........................................................35
32.  Governing Law .........................................................36
33.  Counterparts ..........................................................36
34.  Descriptive Headings ..................................................36


                                       ii
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Exhibit A -- Certificate of Designation of
             Series C-1 Junior Participating
             Cumulative Preferred Stock

Exhibit B -- Form of Right Certificate


                                       iii
<PAGE>

                          SHAREHOLDER RIGHTS AGREEMENT

      Agreement, dated as of November 10, 1994, between T Cell Sciences, Inc., a
Delaware corporation (the "Company"), and State Street Bank and Trust Company, a
Massachusetts trust company (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 November 10, 1994, 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, par value
$0.001 per share, of the Company (the "Common Stock") outstanding as of the
close of business on November 29, 1994 (the "Record Date"), and contemplates the
issuance of one Right for each share of Common Stock of the Company issued
(whether originally issued or sold from the Company's treasury) 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 C-1 Junior Participating
Cumulative Preferred Stock of the Company having the rights, powers and
preferences set forth on Exhibit A hereto, upon the terms and subject to the
conditions hereinafter set forth (the "Rights");

      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 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 15% or
more of the shares of Common Stock 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 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").

      Notwithstanding the foregoing, no Person shall become an "Acquiring
Person" as the result


<PAGE>

of an acquisition of Common Stock by the Company which, by reducing the number
of shares outstanding, increases the proportionate number of shares beneficially
owned by such Person to 15% or more of the shares of Common Stock then
outstanding; provided, however, that if a Person shall become the Beneficial
Owner of 15% 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 15% or more of the shares of Common Stock 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," as defined pursuant to the
foregoing provisions of this Section 1(a), has become such inadvertently, and
such Person divests as promptly as practicable a sufficient number of shares of
Common Stock so that such Person would no longer be an "Acquiring Person," as
defined pursuant to the foregoing provisions of this Section 1(a).

            (b) "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.

            (c) A Person shall be deemed the "Beneficial Owner" of, and shall be
deemed to "beneficially own," 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 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," (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


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<PAGE>

           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," 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 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.

           (d) "Business Day" shall mean any day other than a Saturday, Sunday,
or a day on which banking institutions in the Commonwealth of Massachusetts are
authorized or obligated by law or executive order to close.

           (e) "Close of business" on any given date shall mean 5:00 P.M.,
Boston, Massachusetts time, on such date; provided, however, that if such date
is not a Business Day it shall mean 5:00 P.M., Boston, Massachusetts time, on
the next succeeding Business Day.

           (f) "Common Stock" shall mean the Common Stock, par value $0.00l per


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share, of the Company, except that "Common Stock" when used with reference to
any Person other than the Company shall mean the capital stock with the greatest
voting power, or the equity securities or other equity interests having power to
control or direct the management, of such Person or, if such Person is a
Subsidiary of another Person, the Person which ultimately controls such
first-mentioned Person and which has issued and outstanding such capital stock,
equity securities or equity interests.

           (g) "Distribution Date" shall have the meaning defined in Section
3(a) hereof.

           (h) "Exercise Price" shall have the meaning defined in Section 4(a)
hereof.

           (i) "Expiration Date" and "Final Expiration Date" shall have the
meanings set forth in Section 7(a) hereof.

           (j) "Fair Market Value" of any securities or other property shall be
as determined in accordance with Section 11(d) hereof.

           (k) "Person" shall mean 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.

           (l) "Preferred Stock" shall mean shares of Series C-1 Junior
Participating Cumulative Preferred Stock, par value $0.01 per share, of the
Company having the rights and preferences set forth in the form of Certificate
of Designation attached hereto as Exhibit A.

           (m) "Principal Party" shall have the meaning defined in Section
13(b) hereof.

           (n) "Redemption Price" shall have the meaning defined in Section 23
hereof.

           (o) "Section 11(a)(ii) Event" shall have the meaning defined in
Section 11(a)(ii) hereof.

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

           (q) "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.

           (r) "Subsidiary" shall mean, with respect to any Person, any other
Person of which a majority of the voting power of the voting equity securities
or voting interests is owned, directly or indirectly, by such Person, or which
is otherwise controlled by such Person.


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<PAGE>

           (s) "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) 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.

      Section 3. Issue of Right Certificates.

           (a) From the date hereof until the earlier of (i) the close of
business on the tenth Business Day after the Stock Acquisition Date or (ii) the
close of business on the tenth Business Day (or such other Business Day, if any,
as the Board of Directors may determine in its sole discretion) after the date
of the commencement by any Person, other than an Exempt Person, of a tender or
exchange offer if, upon consummation thereof, such Person would be the
Beneficial Owner of 15% or more of the shares of Common Stock 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
registered in the names of the holders of the Common Stock (which certificates
for Common Stock 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. As soon
as practicable after the Company has notified the Rights Agent of the occurrence
of 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 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 hereto (the "Right
Certificates"), evidencing one Right for each share of Common Stock so held. In
the event that an adjustment in the number of Rights per share of Common Stock
has been made pursuant to Section 11(o) hereof, the Company shall 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 issued prior to
the close of business on the Record Date, the Rights will be evidenced by such
certificates for the Common Stock on or until the Distribution Date (or the
earlier redemption, expiration or termination of the Rights), and the registered
holders of the Common Stock 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


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Common Stock outstanding prior to the date of this Agreement shall also
constitute the transfer of the Rights associated with the Common Stock
represented by such certificate.

           (c) Certificates for the Common Stock 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 T Cell Sciences, Inc. and State Street Bank
                  and Trust Company, as Rights Agent, dated as of November 10,
                  1994 (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 T Cell Sciences, Inc. 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. T Cell
                  Sciences, Inc. may redeem the Rights at a redemption price of
                  $0.01 per Right, subject to adjustment, under the terms of the
                  Rights Agreement. T Cell Sciences, Inc. 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. Under certain
                  circumstances, 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,
                  may become null and void.

With respect to such certificates containing the foregoing legend, the Rights
associated with the Common Stock 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 represented by such certificates. In the event that the
Company purchases or acquires any shares of Common Stock after the Record Date
but prior to the Distribution Date, any Rights associated with such Common Stock
shall be deemed cancelled and retired so that the Company shall not be entitled
to exercise any Rights associated with the shares of Common Stock which are no
longer outstanding. The failure to print the foregoing legend on any such Common
Stock 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 4. Form of Right Certificates.

           (a) The Right Certificates (and the forms of election to purchase
shares and of


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assignment and certificate to be printed on the reverse thereof) shall each be
substantially in the form of Exhibit B 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 Rights 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 be dated as of the Record Date, 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 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 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.


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<PAGE>

      Section 5. Countersignature and Registration.

           (a) The Right Certificates shall be executed on behalf of the Company
by its Chairman of the Board, 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. 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 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 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


                                       8
<PAGE>

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 November
10, 2004 (the "Final Expiration Date"), (ii) the time at which the Rights are
redeemed as provided in Section 23 hereof or (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 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 in accordance with the provisions of this Agreement, as of the date such
Person becomes a record holder of shares of Common Stock.

           (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 $16.00,
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) 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,


                                       9
<PAGE>

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) in cash, or by certified check or bank draft payable to the order of the
Company, the Rights Agent shall, subject to Section 20(k) hereof, thereupon
promptly (i)(A) requisition from any transfer agent of Preferred Stock (or make
available, if the Rights Agent is the transfer agent therefor) certificates for
the number of one one-thousandths of a share of Preferred Stock to be purchased
and the Company hereby irrevocably authorizes its transfer agent to comply with
all such requests, or (B) if the Company shall have elected to deposit the total
number of shares of Preferred Stock issuable upon exercise of the Rights
hereunder with a depositary agent, requisition from the depositary agent
depositary receipts representing such number of one one-thousandths of a share
of Preferred Stock as are to be purchased (in which case certificates for the
shares of Preferred Stock represented by such receipts shall be deposited by the
transfer agent with the depositary agent) and the Company will direct the
depositary agent to comply with such request, (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.

           (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, 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 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 become 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


                                       10
<PAGE>

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 cancellation or in cancelled form,
or, if surrendered to the Rights Agent, shall be cancelled 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
cancelled 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.

           (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
is listed or, if the principal market for the Common Stock is not on any
national securities exchange, to be eligible for quotation on the National
Association of Securities Dealers Automated Quotation System ("NASDAQ") or any
successor thereto or other comparable 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,


                                       11
<PAGE>

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 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 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 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. Prior to
the exercise of the Right evidenced thereby, the holder of a Right Certificate


                                       12
<PAGE>

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 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, he 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 (a "Section 11(a)(ii)
           Event"), then promptly following any such occurrence, 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 and dividing that product by (y) 50% of the
           Fair Market


                                       13
<PAGE>

           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.

                 (iii) In the event that there shall not be sufficient
           authorized but unissued shares of Preferred Stock to permit the
           exercise in full of the Rights in accordance with the foregoing
           Section 11(a)(ii), the Company shall take all action as may be
           necessary to authorize and reserve for issuance such number of
           additional shares of Preferred Stock as may from time to time be
           required to be issued upon the exercise in full of all Rights
           outstanding and, if necessary, shall use its best efforts to obtain
           shareholder approval thereof. Notwithstanding the foregoing
           provisions of this Section 11(a)(iii), in lieu of issuing shares of
           Preferred Stock in accordance with Section 11(a)(ii) hereof, if a
           majority of the Directors then in office determines that such action
           is necessary or appropriate and is not contrary to the interests of
           the holders of the Rights, they may elect to cause the Company to
           pay, and if sufficient shares of Preferred Stock cannot be issued for
           such purpose in accordance with the provisions hereof, the Company
           shall issue or pay upon the exercise of the Rights, cash, property,
           debt securities, shares of preferred stock or common stock, or any
           combination thereof, having an aggregate Fair Market Value equal to
           the Fair Market Value of the shares of Preferred Stock which
           otherwise would have been issuable pursuant to Section 11(a)(ii).
           Any such election by a majority of the Directors of the Company must
           be made and publicly announced within 30 days of the date on which
           any Section 11(a)(ii) Event first occurs following the Stock
           Acquisition 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 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 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


                                       14
<PAGE>

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. 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 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 capital 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


                                       15
<PAGE>

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 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, 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, 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


                                       16
<PAGE>

           of such terms are defined in the Certificate of Designation attached
           as Exhibit A hereto) 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, 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.

           (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 or
ten-millionth of a share of Preferred Stock, as the case may be, or to such
other figure as the Board of Directors 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) 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), (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 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


                                       17
<PAGE>

number of one one-thousandths of a share of Preferred Stock (calculated to the
nearest one ten-millionth) 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 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
one one-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.

           (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


                                       18
<PAGE>

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 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 it in its sole discretion 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, (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 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 a Person who constitutes, or would constitute, the
"Principal Party" for the purposes of Section 13(a) hereof shall have received a
distribution of Rights previously owned by such Person or any of its Affiliates
and Associates. 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) 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 payable in shares of Common Stock or (ii) effect a
subdivision, combination or consolidation of the outstanding shares of Common
Stock (by reclassification or otherwise than


                                       19
<PAGE>

by payment of dividends in shares of Common Stock) into a greater or lesser
number of shares of Common Stock, 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 outstanding immediately prior to such event and the
denominator of which is the number of shares of Common Stock outstanding
immediately after such event, and (B) each share of Common Stock outstanding
immediately after such event shall have issued with respect to it that number of
Rights which each share of Common Stock 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 the Principal
Party 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 a copy of such certificate and (c) mail a
brief summary thereof to each holder of a Right Certificate 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
Person (other than a Subsidiary of the Company in a transaction which is not
prohibited by 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 connection with such merger, all or part of
the shares of Common Stock 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


                                       20
<PAGE>

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 or any Subsidiary
of the Company in one or more transactions, each of which is not prohibited by
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 the Principal Party (as hereinafter defined in
Section 13(b)), free and clear of rights of call or first refusal, liens,
encumbrances 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 Principal Party on the date
of consummation of such consolidation, merger, sale or transfer; (ii) such
Principal Party 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 Principal Party, it being specifically
intended that the provisions of Section 11 hereof shall apply to such Principal
Party; and (iv) such Principal Party 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) "Principal Party" shall mean

                 (i) in the case of any transaction described in clause (x) or
      (y) of the first sentence of Section 13(a), the Person that is the issuer
      of any securities into which shares of Common Stock of the Company are
      converted in such merger or consolidation, and if no securities are so
      issued, the Person that is the other party to the merger or consolidation;
      and

                 (ii) in the case of any transaction described in clause (z) of
      the first sentence of Section 13(a), the Person that is the party
      receiving the greatest portion of the assets or earning power transferred
      pursuant to such transaction or transactions;

provided, however, that in any such case, (x) if the Common Stock of such Person
is not at such time and has not been continuously over the preceding 12-month
period registered under Section 12 of the Exchange Act, and such Person is a
direct or indirect Subsidiary or Affiliate of another Person the Common Stock of
which is and has been so registered, "Principal Party" shall refer to such other
Person; (y) in case such Person is a direct or indirect Subsidiary or Affiliate
of more than one Person, the Common Stocks of two or more of which are and have
been so registered, "Principal Party" shall refer to whichever of such Persons
is the issuer of the


                                       21
<PAGE>

Common Stock having the greatest aggregate market value of shares outstanding;
and (z) in case such Person is owned, directly or indirectly, by a joint venture
formed by two or more Persons that are not owned, directly or indirectly, by the
same Person, the rules set forth in (x) and (y) above shall apply to each of the
chains of ownership having an interest in such joint venture as if such party
were a "Subsidiary" of both or all of such joint venturers and the Principal
Parties in each such chain shall bear the obligations set forth in this Section
13 in the same ratio as their direct or indirect interests in such Person bear
to the total of such interests.

           (c) The Company shall not consummate any such consolidation, merger,
sale or transfer unless prior thereto (x) the Principal Party 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 each Principal Party
and each other Person who may become a Principal Party as a result of such
consolidation, merger, sale or transfer 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), the Principal Party 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 an appropriate form, use its best efforts
      to cause such registration statement to become effective as soon as
      practicable after such filing and use its best efforts to 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) use its best efforts to 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) use its best efforts to 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 the Principal Party and each of its Affiliates which comply
      in all material respects with the requirements for registration on Form 10
      under the Exchange Act.

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


                                       22
<PAGE>

holders of the Right Certificates with regard to which such fractional Rights
would otherwise 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); and any registered holder of any Right Certificate
(or, prior to the Distribution Date, of the Common Stock), without the consent
of the Right Agent or of the holder of any other Right Certificate (or, prior to
the Distribution Date, of the Common Stock), may, on his own behalf and for his
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.

      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:

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

           (b) after the Distribution Date, the Right Certificates are
transferable only on


                                       23
<PAGE>

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) 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 Common Stock certificate) 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 Common Stock certificate
made by anyone other than the Company or the Rights Agent) for all purposes
whatsoever, and 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 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


                                       24
<PAGE>

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 for Common Stock, 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 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 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,


                                       25
<PAGE>

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, a Vice
Chairman of the Board, 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 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
or Preferred Stock to be issued pursuant to this Agreement or any Right
Certificate or as to whether any shares of Common Stock or Preferred Stock will,
when so issued, be validly authorized and issued, fully paid and nonassessable.


                                       26
<PAGE>

            (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, any Vice Chairman of the
Board, 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 hereby vested in it or perform any duty hereunder either itself or by or
through its attorneys or agents, and the Rights Agent shall not be answerable or
accountable for any act, omission, default, neglect or misconduct of any such
attorneys or agents or for any loss to the Company or to the holders of the
Rights resulting from any such act, omission, default, neglect or misconduct,
provided reasonable care was exercised in the selection and continued employment
thereof.

            (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.


                                       27
<PAGE>

            (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) upon thirty (30) days' notice in writing, mailed to the
Rights Agent or successor Rights Agent, as the case may be, and to each transfer
agent of the Common Stock and Preferred Stock by registered or certified mail,
and to the holders of the Right Certificates by first-class mail. 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 of the Commonwealth of Massachusetts 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 Commonwealth of Massachusetts or 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
$50,000,000 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 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
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 its Board of Directors


                                       28
<PAGE>

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 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 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 and Termination.

            (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 in shares of Common Stock or any subdivision or
combination of the outstanding shares of Common Stock 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 earliest to occur of (i) 5:00 P.M., Boston,
Massachusetts time, on the tenth Business Day after the Stock Acquisition Date
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, 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 Right so held. Promptly after the action of the Board
of Directors ordering the redemption of the Rights, 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. 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 prior to the Distribution Date.

            (c) The Company may, at its option, pay the Redemption Price in
cash, shares


                                       29
<PAGE>

of Common Stock (based on the Fair Market Value of the Common Stock as of the
time of redemption) or any other form of consideration deemed appropriate by the
Board of Directors.

      Section 24. Exchange.

            (a) 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 at an exchange ratio of one share of Common Stock 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 "Exchange Ratio"). Notwithstanding the foregoing,
the Board of Directors 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 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 equal to the number of such Rights
held by such holder multiplied by the Exchange Ratio. The Company shall promptly
give notice of any such exchange in accordance with Section 26 hereof; provided,
however, that the failure to give, or any defect in, such notice shall not
affect the validity of such exchange. Each such notice of exchange will state
the method by which the exchange of the shares of Common Stock 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 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, 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 shall have the same voting
rights as one share of Common Stock.

            (d) In the event that there shall not be sufficient shares of Common
Stock or Preferred Stock (or preferred stock equivalent) 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 or
Preferred Stock (or preferred stock equivalent) for issuance upon exchange of
the Rights.


                                       30
<PAGE>

            (e) The Company shall not be required to issue fractions of Common
Stock or to distribute certificates which evidence fractional shares of Common
Stock. If the Company elects not to issue such fractional shares of Common
Stock, the Company shall pay, in lieu of such fractional shares of Common Stock,
to the registered holders of the Right Certificates with regard to which such
fractional shares of Common Stock 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. For the purposes of this paragraph (e), the Fair Market Value of a whole
share of Common Stock shall be the closing price of a share of Common Stock (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 Section 11(n) hereof),
or (v) to effect the liquidation, dissolution or winding up of the Company, (vi)
to declare or pay any dividend on the Common Stock payable in Common Stock or to
effect a subdivision, combination or consolidation of the Common Stock (by
reclassification or otherwise than by payment of dividends in Common Stock) 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 the holders of the shares of Common Stock 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
and/or Preferred Stock, whichever shall be the earlier.

            (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


                                       31
<PAGE>

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, addressed (until another address is filed in writing with
the Rights Agent) as follows:

            T Cell Sciences, Inc.
            115 4th Avenue
            Needham, MA 02194

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, addressed (until another address is
filed in writing with the Company) as follows:

            State Street Bank and Trust Company
            c/o Boston Financial Data Services, Inc.
            Two Heritage Drive
            Quincy, MA 02171
            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) shall be 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 Distribution Date,
the Company and the Rights Agent shall, if the Company so directs, supplement or
amend any provision of this Agreement as the Company may deem necessary or
desirable without the approval of any holders of certificates representing
shares of Common Stock. From and after the Distribution Date, the Company and
the Rights Agent shall, if 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 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
Distribution Date 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


                                       32
<PAGE>

rights of, and the benefits to, the holders of Rights. 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
Distribution Date, the interests of the holders of Rights shall be deemed
coincident with the interests of the holders of Common Stock. 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. For all
purposes of this Agreement, any calculation of the number of shares of Common
Stock outstanding at any particular time, including for purposes of determining
the particular percentage of such outstanding shares of Common Stock of which
any Person is the Beneficial Owner, shall be made in accordance with the last
sentence of Rule 13d-3(d)(1)(i) of the Rules under the Exchange Act as in effect
on the date hereof. 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 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 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) 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).

      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.


                                       33
<PAGE>

      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 Delaware.

      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.


                  [Remainder of page intentionally left blank.]


                                       34
<PAGE>

      IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed and their respective corporate seals to be hereunto affixed and
attested, all as of the day and year first above written.


ATTEST:                                 T CELL SCIENCES, INC.


By: _______________________             By: ________________________________
                                            Name:
                                            Title:


ATTEST:                                 STATE STREET BANK AND
                                         TRUST COMPANY, as Rights Agent


By: _______________________             By: ________________________________
                                            Name:
                                            Title:


<PAGE>

                                                                       Exhibit A

                         VOTE OF DIRECTORS ESTABLISHING
                   Series C-1 JUNIOR PARTICIPATING CUMULATIVE
                                 PREFERRED STOCK

                                       of

                              T CELL SCIENCES, INC.

      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 Third Restated Certificate of Incorporation, as amended as
of the date hereof (the "Certificate of Incorporation"), of T Cell Sciences,
Inc. (the "Corporation"), the Board of Directors hereby establishes and
designates a series of Class C 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 C-1 Junior Participating Cumulative Preferred Stock" (the
"Series C-1 Preferred Stock"), and the number of shares initially constituting
such series shall be 350,000; provided, however, that if more than a total of
350,000 shares of Series C-1 Preferred Stock shall be issuable upon the exercise
of Rights (the "Rights") issued pursuant to the Shareholder Rights Agreement
dated as of November 10, 1994, between the Corporation and State Street Bank and
Trust Company, 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, shall 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 C-1 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 C-1 Preferred Stock with respect to dividends, the holders of shares of
Series C-1 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 share of
Series C-1

<PAGE>

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, 1000 times the aggregate per share amount of all cash
dividends, and 1000 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 C-1 Preferred Stock. The multiple of cash and
non-cash dividends declared on the common stock to which holders of the Series
C-1 Preferred Stock are entitled, which shall be 1000 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 November 10, 1994 (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 C-1
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 C-1 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 C-1 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 C-1 Preferred Stock from the Quarterly Dividend Payment Date
next preceding the date of issue of such shares of Series C-1 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 C-1 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 C-1
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 Board of
Directors may fix in accordance with applicable law a record date for the
determination of holders of shares of Series C-1 Preferred Stock entitled to
receive payment of a dividend or distribution declared


                                       2
<PAGE>

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 C-1 Preferred Stock shall have the
following voting rights:

      (A) Subject to the provision for adjustment hereinafter set forth, each
share of Series C-1 Preferred Stock shall entitle the holder thereof to 1000
votes on all matters submitted to a vote of the stockholders of the Corporation.
The number of votes which a holder of a share of Series C-1 Preferred Stock is
entitled to cast, which shall initially be 1000 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 C-1 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 C-1 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 stockholders of the Corporation.

      (C) Except as otherwise required by applicable law or as set forth herein,
holders of Series C-1 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 C-1
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 C-1 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 (either as to dividends or upon liquidation,
            dissolution or winding up) to the Series C-1 Preferred Stock;

      (ii)  declare or pay dividends on or make any other distributions on any
            shares of stock


                                       3
<PAGE>

            ranking on a parity (either as to dividends or upon liquidation,
            dissolution or winding up) with the Series C-1 Preferred Stock,
            except dividends paid ratably on the Series C-1 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 C-1 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 C-1
            Preferred Stock; or

      (iv)  purchase or otherwise acquire for consideration any shares of Series
            C-1 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 C-1 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 C-1 Preferred Stock
purchased or otherwise acquired by the Corporation in any manner whatsoever
shall be retired and cancelled 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 C-1 Preferred Stock unless, prior thereto, the holders of shares of
Series C-1 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) $1000.00 per share
or (2) an aggregate amount per share, subject to the provision for adjustment
hereinafter set forth, equal to 1000 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 C-1 Preferred Stock, except


                                       4
<PAGE>

distributions made ratably on the Series C-1 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 C-1 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 C-1 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 1000 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
C-1 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 C-1 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.

      Section 8. Redemption. The shares of Series C-1 Preferred Stock shall not
be redeemable.

      Section 9. Ranking. Unless otherwise provided in the Certificate of
Incorporation or a Certificate of Vote of Directors Establishing a Class of
Stock relating to a subsequently-designated series of preferred stock of the
Corporation, the Series C-1 Preferred Stock shall rank junior to any other
series of the Corporation's preferred stock subsequently issued, 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.


                                       5
<PAGE>

      Section 10. Amendment. The Certificate of Incorporation and this
Certificate of Vote of Directors shall not be amended in any manner which would
materially alter or change the powers, preferences or special rights of the
Series C-1 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 C-1 Preferred Stock, voting separately as a class.

      Section 11. Fractional Shares. Series C-1 Preferred Stock may be issued in
whole shares or in any fraction of a share that is one one-thousandth (1/1000th)
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 C-1 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
(1/1000th) of a share or any integral multiple thereof.


                                       6
<PAGE>

                                                                       Exhibit B

                           [Form of Right Certificate]

Certificate No. R-                                                  _____ Rights

NOT EXERCISABLE AFTER NOVEMBER 10, 2004 OR EARLIER IF NOTICE OF REDEMPTION IS
GIVEN. THE RIGHTS ARE SUBJECT TO REDEMPTION, AT THE OPTION OF T CELL SCIENCES,
INC., AT $0.01 PER RIGHT ON THE TERMS SET FORTH IN THE SHAREHOLDER RIGHTS
AGREEMENT BETWEEN T CELL SCIENCES, INC. AND STATE STREET BANK AND TRUST COMPANY,
AS RIGHTS AGENT, DATED AS OF NOVEMBER 10, 1994 (THE "RIGHTS AGREEMENT"). UNDER
CERTAIN CIRCUMSTANCES 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 MAY BECOME NULL AND VOID.

Right Certificate

T CELL SCIENCES, INC.

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 November 10, 1994 (the "Rights
Agreement") between T CELL SCIENCES, INC. (the "Company") and STATE STREET BANK
AND TRUST COMPANY, 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 November 10, 2004 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 C-1 Junior Participating Cumulative Preferred Stock (the
"Preferred Stock") of the Company, at a purchase price of $16.00 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.

<PAGE>

      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) of one share of Common Stock or one one-thousandth of a share of
Preferred Stock per Right.

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


                                       2
<PAGE>

      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 stockholder of the Company or any right to vote for the
election of directors or upon any matter submitted to stockholders at any
meeting thereof, or to give or withhold consent to any corporate action, or to
receive notice of meetings or other actions affecting stockholders (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.


                                       3
<PAGE>

      WITNESS the facsimile signature of the proper officers of the Company and
its corporate seal.


[Corporate Seal]                         T CELL SCIENCES, INC.


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


Countersigned:

STATE STREET BANK
 AND TRUST COMPANY,
as Rights Agent


Authorized Signatory

Date of countersignature:


                                       4
<PAGE>

                   [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


                                       5
<PAGE>

                                     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.


                                       6
<PAGE>

                          FORM OF ELECTION TO PURCHASE

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

To T CELL SCIENCES, INC.:

      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: ____________


                                       7
<PAGE>

                                   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


                                       8
<PAGE>

                                     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.