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                                RIGHTS AGREEMENT

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                                  COVANCE INC.

                                       and

                          HARRIS TRUST AND SAVINGS BANK

                                  Rights Agent

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                          Dated as of December 31, 1996

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                                TABLE OF CONTENTS

                                                                          Page
                                                                          ---- 
Section 1.    Certain Definitions........................................   1

Section 2.    Appointment of Rights Agent................................   3

Section 3.    Issue of Right Certificates................................   3

Section 4.    Form of Right Certificates.................................   5

Section 5.    Countersignature and Registration..........................   5

Section 6.    Transfer, Split Up, Combination and
                  Exchange of Right Certificates;
                  Mutilated, Destroyed, Lost or
                  Stolen Right Certificates..............................   6

Section 7.    Exercise of Rights; Purchase Price;
                  Expiration Date of Rights..............................   7

Section 8.    Cancellation and Destruction of
                  Right Certificates.....................................   7

Section 9.    Availability of Preferred Shares...........................   8

Section 10.   Preferred Shares Record Date...............................   8

Section 11.   Adjustment of Purchase Price, Number of
                  Shares or Number of Rights.............................   8

Section 12.   Certificate of Adjusted Purchase Price
                  or Number of Shares....................................  14

Section 13.   Consolidation, Merger or Sale or Transfer
                  of Assets or Earning Power.............................  14

Section 14.   Fractional Rights and Fractional Shares....................  15

Section 15.   Rights of Action...........................................  16

Section 16.   Agreement of Right Holders.................................  17

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Section 17.   Right Certificate Holder Not Deemed a
                  Stockholder............................................  17

Section 18.   Concerning the Rights Agent................................  17

Section 19.   Merger or Consolidation or Change of
                  Name of Rights Agent...................................  18

Section 20.   Duties of Rights Agent.....................................  18

Section 21.   Change of Rights Agent.....................................  20

Section 22.   Issuance of New Right Certificates.........................  21

Section 23.   Redemption.................................................  21

Section 24.   Exchange...................................................  21

Section 25.   Notice of Certain Events...................................  23

Section 26.   Notices....................................................  23

Section 27.   Supplements and Amendments.................................  24

Section 28.   Successors.................................................  24

Section 29.   Benefits of this Agreement.................................  24

Section 30.   Severability...............................................  25

Section 31.   Governing Law..............................................  25

Section 32.   Counterparts...............................................  25

Section 33.   Descriptive Headings.......................................  25

Signatures...............................................................  25

Exhibit A - Form of Right Certificate
Exhibit B - Form of Summary of Rights to Purchase Preferred Shares


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     AGREEMENT, dated as of December 31, 1996, between Covance Inc., a Delaware
corporation (the "Company"), and Harris Trust and Savings Bank (the "Rights
Agent").

     The Board of Directors of the Company has authorized and declared a
dividend of one preferred share purchase right (a "Right") for each Common Share
(as hereinafter defined) of the Company outstanding on December 31, 1996 (the
"Record Date"), each Right representing the right to purchase one one-hundredth
of a Preferred Share (as hereinafter defined), upon the terms and subject to the
conditions herein set forth, and has further authorized and directed the
issuance of one Right with respect to each Common Share that shall become
outstanding between the Record Date and the earliest of the Distribution Date,
the Redemption Date and the Final Expiration Date (as such terms are hereinafter
defined).

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

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

     (a) "Acquiring Person" shall mean any Person (as such term is hereinafter
defined) who or which, together with all Affiliates and Associates (as such
terms are hereinafter defined) of such Person, shall be the Beneficial Owner (as
such term is hereinafter defined) of 20% or more of the Common Shares of the
Company then outstanding, but shall not include the Company, any Subsidiary (as
such term is hereinafter defined) of the Company, any employee benefit plan of
the Company or any Subsidiary of the Company, or any entity holding Common
Shares for or pursuant to the terms of any such plan. Notwithstanding the
foregoing, no Person shall become an "Acquiring Person" as the result of an
acquisition of Common Shares by the Company which, by reducing the number of
shares outstanding, increases the proportionate number of shares beneficially
owned by such Person to 20% or more of the Common Shares of the Company then
outstanding; provided, however, that if a Person shall become the Beneficial
Owner of 20% or more of the Common Shares 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 Common Shares of
the Company, then such Person shall be deemed to be an "Acquiring Person".
Notwithstanding the foregoing, if the Board of Directors of the Company
determines in good faith that a Person who would otherwise be an "Acquiring
Person", as defined pursuant to the foregoing provisions of this paragraph (a),
has become such inadvertently, and such Person divests as promptly as
practicable a sufficient number of Common Shares so that such Person would no
longer be an "Acquiring Person," as defined pursuant to the foregoing provisions
of this paragraph (a), then such Person shall not be deemed to be an "Acquiring
Person" for any purposes of this Agreement.

     (b) "Affiliate" and "Associate" shall have the respective meanings ascribed
to such terms in Rule 12b-2 of the General Rules and Regulations under the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), as in effect
on the date of this Agreement.

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     (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 beneficially owns, directly or indirectly;

              (ii) which such Person or any of such Person's Affiliates or
         Associates has (A) the right to acquire (whether such right is
         exercisable immediately or only after the passage of time) pursuant to
         any agreement, arrangement or understanding (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
         these Rights), warrants or options, or otherwise; provided, however,
         that a Person shall not be deemed the Beneficial Owner of, or to
         beneficially own, 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; or (B) the right to vote pursuant to any
         agreement, arrangement or understanding; provided, however, that a
         Person shall not be deemed the Beneficial Owner of, or to beneficially
         own, any security if the agreement, arrangement or understanding to
         vote such security (1) arises solely from a revocable proxy or consent
         given to such Person in response to a public proxy or consent
         solicitation made pursuant to, and in accordance with, the applicable
         rules and regulations promulgated under the Exchange Act and (2) is not
         also then reportable on Schedule 13D under the Exchange Act (or any
         comparable or successor report); or

              (iii) which are beneficially owned, directly or indirectly, by any
         other Person with which such Person or any of such Person's Affiliates
         or Associates has any agreement, arrangement or understanding (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 to
         the extent contemplated by the proviso to Section 1(c)(ii)(B)) or
         disposing of any securities of the Company.

                  Notwithstanding anything in this definition of Beneficial
Ownership to the contrary, the phrase "then outstanding," when used with
reference to a Person's Beneficial Ownership of securities of the Company, shall
mean the number of such securities then issued and outstanding together with the
number of such securities not then actually issued and outstanding which such
Person would be deemed to own beneficially hereunder.

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

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

     (f) "Common Shares" when used with reference to the Company shall mean the
shares of common stock, par value $.01 per share, of the Company. "Common
Shares" when used with reference to any Person other than the Company shall mean
the capital stock (or equity interest) with the greatest voting power of such
other Person or, if such other Person is a Subsidiary of another Person, the
Person or Persons which ultimately control such first-mentioned Person.

     (g) "Distribution Date" shall have the meaning set forth in Section 3
hereof.

     (h) "Final Expiration Date" shall have the meaning set forth in Section 7
hereof.

     (i) "Person" shall mean any individual, firm, corporation or other entity,
and shall include any successor (by merger or otherwise) of such entity.

     (j) "Preferred Shares" shall mean shares of Series A Junior Participating
Preferred Stock, par value $1.00 per share, of the Company.

     (k) "Redemption Date" shall have the meaning set forth in Section 7 hereof.

     (l) "Shares Acquisition Date" shall mean the first date of public
announcement by the Company or an Acquiring Person that an Acquiring Person has
become such.

     (m) "Subsidiary" of any Person shall mean any corporation or other entity
of which a majority of the voting power of the voting equity securities or
equity interest is owned, directly or indirectly, by such Person.

     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 also
be the holders of the Common Shares) 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.

     Section 3. Issue of Right Certificates. (a) Until the earlier of (i) the
tenth day after the Shares Acquisition Date or (ii) the tenth business day (or
such later date as may be determined by action of the Board of Directors prior
to such time as any Person becomes an Acquiring Person) after the date of the
commencement by any Person (other than the Company, any Subsidiary of the
Company, any employee benefit plan of the Company or of any Subsidiary of the
Company or any entity holding Common Shares for or pursuant to the terms of any
such plan) of, or of the first public announcement of the intention of any
Person

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(other than the Company, any Subsidiary of the Company, any employee benefit
plan of the Company or of any Subsidiary of the Company or any entity holding
Common Shares for or pursuant to the terms of any such plan) to commence, a
tender or exchange offer the consummation of which would result in any Person
becoming the Beneficial Owner of Common Shares aggregating 20% or more of the
then outstanding Common Shares (including any such date which is after the date
of this Agreement and prior to the issuance of the Rights; the earlier 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 Common Shares registered in the names of the holders thereof
(which certificates shall also be deemed to be Right Certificates) and not by
separate Right Certificates, and (y) the right to receive Right Certificates
will be transferable only in connection with the transfer of Common Shares. As
soon as practicable after the Distribution Date, the Company will prepare and
execute, the Rights Agent will countersign, and the Company will send or cause
to be sent (and the Rights Agent will, if requested, send) by first-class,
insured, postage-prepaid mail, to each record holder of Common Shares as of the
close of business on the Distribution Date, at the address of such holder shown
on the records of the Company, a Right Certificate, in substantially the form of
Exhibit A hereto (a "Right Certificate"), evidencing one Right for each Common
Share so held. As of the Distribution Date, the Rights will be evidenced solely
by such Right Certificates.

     (b) On the Record Date, or as soon as practicable thereafter, the Company
will send a copy of a Summary of Rights to Purchase Preferred Shares, in
substantially the form of Exhibit B hereto (the "Summary of Rights"), by
first-class, postage-prepaid mail, to each record holder of Common Shares as of
the close of business on the Record Date, at the address of such holder shown on
the records of the Company. With respect to certificates for Common Shares
outstanding as of the Record Date, until the Distribution Date, the Rights will
be evidenced by such certificates registered in the names of the holders thereof
together with a copy of the Summary of Rights attached thereto. Until the
Distribution Date (or the earlier of the Redemption Date or the Final Expiration
Date), the surrender for transfer of any certificate for Common Shares
outstanding on the Record Date, with or without a copy of the Summary of Rights
attached thereto, shall also constitute the transfer of the Rights associated
with the Common Shares represented thereby.

     (c) Certificates for Common Shares which become outstanding (including,
without limitation, reacquired Common Shares referred to in the last sentence of
this paragraph (c)) after the Record Date but prior to the earliest of the
Distribution Date, the Redemption Date or the Final Expiration Date shall have
impressed on, printed on, written on or otherwise affixed to them the following
legend:

    This certificate also evidences and entitles the holder hereof to certain
    rights as set forth in a Rights Agreement between Covance Inc. and Harris
    Trust and Savings Bank, dated as of December 31, 1996 (the "Rights
    Agreement"), the terms of which are hereby incorporated herein by reference
    and a copy of which is on file at the principal executive offices of Covance
    Inc. Under certain circumstances, as set forth in the Rights Agreement, such
    Rights will be evidenced by separate certificates and will no

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    longer be evidenced by this certificate. Covance Inc. will mail to the
    holder of this certificate a copy of the Rights Agreement without charge
    after receipt of a written request therefor. Under certain circumstances, as
    set forth in the Rights Agreement, Rights issued to any Person who becomes
    an Acquiring Person (as defined in the Rights Agreement) may become null and
    void.

With respect to such certificates containing the foregoing legend, until the
Distribution Date, the Rights associated with the Common Shares represented by
such certificates shall be evidenced by such certificates alone, and the
surrender for transfer of any such certificate shall also constitute the
transfer of the Rights associated with the Common Shares represented thereby. In
the event that the Company purchases or acquires any Common Shares after the
Record Date but prior to the Distribution Date, any Rights associated with such
Common Shares shall be deemed cancelled and retired so that the Company shall
not be entitled to exercise any Rights associated with the Common Shares which
are no longer outstanding.

     Section 4. Form of Right Certificates. The Right Certificates (and the
forms of election to purchase Preferred Shares and of assignment to be printed
on the reverse thereof) shall be substantially the same as Exhibit A 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 or with any rule or regulation made pursuant
thereto 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 usage. Subject to the
provisions of Section 22 hereof, the Right Certificates shall entitle the
holders thereof to purchase such number of one one-hundredths of a Preferred
Share as shall be set forth therein at the price per one one-hundredth of a
Preferred Share set forth therein (the "Purchase Price"), but the number of such
one one-hundredths of a Preferred Share and the Purchase Price shall be subject
to adjustment as provided herein.

     Section 5. Countersignature and Registration. The Right Certificates shall
be executed on behalf of the Company by its Chairman of the Board, its Vice
Chairman, its Chief Executive Officer, its President, any of its Vice
Presidents, or its Treasurer, either manually or by facsimile signature, shall
have affixed thereto the Company's seal or a facsimile thereof, and shall be
attested by the Secretary or an Assistant Secretary of the Company, either
manually or by facsimile signature. The Right Certificates shall be manually
countersigned by the Rights Agent and shall not be valid for any purpose unless
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 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 Certificate 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

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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.

     Following the Distribution Date, the Rights Agent will keep or cause to be
kept, at its principal office, 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. Subject
to the provisions of 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
earlier of the Redemption Date or the Final Expiration Date, any Right
Certificate or Right Certificates (other than Right Certificates representing
Rights that have become void pursuant to Section 11(a)(ii) hereof or that have
been exchanged pursuant to Section 24 hereof) may be transferred, split up,
combined or exchanged for another Right Certificate or Right Certificates,
entitling the registered holder to purchase a like number of one one-hundredths
of a Preferred Share as the Right Certificate or Right Certificates surrendered
then entitled such holder to purchase. Any registered holder desiring to
transfer, split up, combine or exchange any Right Certificate or Right
Certificates shall make such request in writing delivered to the Rights Agent,
and shall surrender the Right Certificate or Right Certificates to be
transferred, split up, combined or exchanged at the principal office of the
Rights Agent. Thereupon, the Rights Agent shall countersign and deliver to the
person entitled thereto a Right Certificate or Right Certificates, as the case
may be, as so requested. The Company may require payment 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.

     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 reasonably satisfactory to them, and, at the Company's request,
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 make and deliver a new
Right Certificate of like tenor to the Rights Agent for delivery to the
registered holder in lieu of the Right Certificate so lost, stolen, destroyed or
mutilated.

     Section 7. Exercise of Rights; Purchase Price; Expiration Date of Rights.
(a) 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 on the reverse side thereof duly executed,
to the Rights Agent at the principal office of the Rights Agent, together with
payment of the Purchase Price for each one one-hundredth of a Preferred Share as
to which the Rights are exercised, at or prior to the earliest of (i) the close
of business on December 31, 2006 (the "Final Expiration Date"), (ii) the time at
which the Rights are

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redeemed as provided in Section 23 hereof (the "Redemption Date"), or (iii) the
time at which such Rights are exchanged as provided in Section 24 hereof.

     (b) The Purchase Price for each one one-hundredth of a Preferred Share
purchasable pursuant to the exercise of a Right shall initially be $100, and
shall be subject to adjustment from time to time as provided in Section 11 or 13
hereof and shall be payable in lawful money of the United States of America in
accordance with paragraph (c) below.

     (c) Upon receipt of a Right Certificate representing exercisable Rights,
with the form of election to purchase duly executed, accompanied by payment of
the Purchase Price for the shares to be purchased and an amount equal to any
applicable transfer tax required to be paid by the holder of such Right
Certificate in accordance with Section 9 hereof by certified check, cashier's
check or money order payable to the order of the Company, the Rights Agent shall
thereupon promptly (i) (A) requisition from any transfer agent of the Preferred
Shares certificates for the number of Preferred Shares to be purchased and the
Company hereby irrevocably authorizes its transfer agent to comply with all such
requests, or (B) requisition from the depositary agent depositary receipts
representing such number of one one-hundredths of a Preferred Share as are to be
purchased (in which case certificates for the Preferred Shares represented by
such receipts shall be deposited by the transfer agent with the depositary
agent) and the Company hereby directs the depositary agent to comply with such
request, (ii) when appropriate, requisition from the Company the amount of cash
to be paid in lieu of issuance of fractional shares in accordance with Section
14 hereof, (iii) 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, deliver such cash to or
upon the order of the registered holder of such Right Certificate.

     (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 to the registered holder of such Right Certificate or to his duly
authorized assigns, subject to the provisions of Section 14 hereof.

     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 to 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 Rights 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, or shall, at the written
request of the Company, destroy such cancelled Right Certificates, and in such
case shall deliver a certificate of destruction thereof to the Company.

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     Section 9. Availability of Preferred Shares. The Company covenants and
agrees that it will cause to be reserved and kept available out of its
authorized and unissued Preferred Shares or any Preferred Shares held in its
treasury, the number of Preferred Shares that will be sufficient to permit the
exercise in full of all outstanding Rights in accordance with Section 7. The
Company covenants and agrees that it will take all such action as may be
necessary to ensure that all Preferred Shares delivered upon exercise of Rights
shall, at the time of delivery of the certificates for such Preferred Shares
(subject to payment of the Purchase Price), be duly and validly authorized and
issued and fully paid and nonassessable shares.

     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 Preferred Shares 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 the
issuance or delivery of certificates or depositary receipts for the Preferred
Shares in a name other than that of, the registered holder of the Right
Certificate evidencing Rights surrendered for exercise or to issue or to deliver
any certificates or depositary receipts for Preferred Shares upon the exercise
of any Rights until any 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 reasonable satisfaction that no
such tax is due.

     Section 10. Preferred Shares Record Date. Each person in whose name any
certificate for Preferred Shares is issued upon the exercise of Rights shall for
all purposes be deemed to have become the holder of record of the Preferred
Shares 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 Purchase 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 Shares 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 Shares transfer books of the Company are open. Prior to the exercise
of the Rights evidenced thereby, the holder of a Right Certificate shall not be
entitled to any rights of a holder of Preferred 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 Purchase Price, Number of Shares or Number of
Rights. The Purchase Price, the number of Preferred 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 Shares payable in Preferred
Shares, (B) subdivide the outstanding Preferred Shares, (C) combine the
outstanding Preferred Shares into

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a smaller number of Preferred Shares or (D) issue any shares of its capital
stock in a reclassification of the Preferred Shares (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), the Purchase 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
Shares 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 one Right be less than the
aggregate par value of the shares of capital stock of the Company issuable upon
exercise of one Right.

     (ii) Subject to Section 24 of this Agreement, in the event any Person
becomes an Acquiring Person, each holder of a Right shall thereafter have a
right to receive, upon exercise thereof at a price equal to the then current
Purchase Price multiplied by the number of one one-hundredths of a Preferred
Share for which a Right is then exercisable, in accordance with the terms of
this Agreement and in lieu of Preferred Shares, such number of Common Shares of
the Company as shall equal the result obtained by (x) multiplying the then
current Purchase Price by the number of one one-hundredths of a Preferred Share
for which a Right is then exercisable and dividing that product by (y) 50% of
the then current per share market price of the Company's Common Shares
(determined pursuant to Section 11(d) hereof) on the date of the occurrence of
such event. In the event that any Person shall become an Acquiring Person and
the Rights shall then be outstanding, the Company shall not take any action
which would eliminate or diminish the benefits intended to be afforded by the
Rights.

     From and after the occurrence of such event, any Rights that are or were
acquired or beneficially owned by any Acquiring Person (or any Associate or
Affiliate of such Acquiring Person) shall be void and any holder of such Rights
shall thereafter have no right to exercise such Rights under any provision of
this Agreement. No Right Certificate shall be issued pursuant to Section 3 that
represents Rights beneficially owned by an Acquiring Person whose Rights would
be void pursuant to the preceding sentence or any Associate or Affiliate
thereof; no Right Certificate shall be issued at any time upon the transfer of
any Rights to an Acquiring Person whose Rights would be void pursuant to the
preceding sentence or any Associate or Affiliate thereof or to any nominee of
such Acquiring Person, Associate or Affiliate; and any Right Certificate
delivered to the Rights Agent for transfer to an Acquiring Person whose Rights
would be void pursuant to the preceding sentence shall be cancelled.

   
     (iii) In the event that there shall not be sufficient Common Shares issued
but not outstanding or authorized but unissued to permit the exercise in full of
the Rights in accordance with the foregoing subparagraph (ii), the Company shall
take all such action as may be necessary to authorize additional Common Shares
for issuance upon exercise of the Rights. In the event the Company shall, after
good faith effort, be unable to take all such
    

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action as may be necessary to authorize such additional Common Shares, the
Company shall substitute, for each Common Share that would otherwise be issuable
upon exercise of a Right, a number of Preferred Shares or fraction thereof such
that the current per share market price of one Preferred Share multiplied by
such number or fraction is equal to the current per share market price of one
Common Share as of the date of issuance of such Preferred Shares or fraction
thereof.
    

     (b) In case the Company shall fix a record date for the issuance of rights,
options or warrants to all holders of Preferred Shares entitling them (for a
period expiring within 45 calendar days after such record date) to subscribe for
or purchase Preferred Shares (or shares having the same rights, privileges and
preferences as the Preferred Shares ("equivalent preferred shares")) or
securities convertible into Preferred Shares or equivalent preferred shares at a
price per Preferred Share or equivalent preferred share (or having a conversion
price per share, if a security convertible into Preferred Shares or equivalent
preferred shares) less than the then current per share market price of the
Preferred Shares (as defined in Section 11(d)) on such record date, the Purchase
Price to be in effect after such record date shall be determined by multiplying
the Purchase Price in effect immediately prior to such record date by a
fraction, the numerator of which shall be the number of Preferred Shares
outstanding on such record date plus the number of Preferred Shares which the
aggregate offering price of the total number of Preferred Shares and/or
equivalent preferred shares so to be offered (and/or the aggregate initial
conversion price of the convertible securities so to be offered) would purchase
at such current market price and the denominator of which shall be the number of
Preferred Shares outstanding on such record date plus the number of additional
Preferred Shares and/or equivalent preferred shares to be offered for
subscription or purchase (or into which the convertible securities so to be
offered are initially convertible); provided, however, that in no event shall
the consideration to be paid upon the exercise of one Right be less than the
aggregate par value of the shares of capital stock of the Company issuable upon
exercise of one 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 as determined in good faith by the Board of
Directors of the Company, whose determination shall be described in a statement
filed with the Rights Agent. Preferred Shares owned by or held for the account
of the Company shall not be deemed outstanding for the purpose of any such
computation. Such adjustment shall be made successively whenever such a record
date is fixed; and in the event that such rights, options or warrants are not so
issued, the Purchase Price shall be adjusted to be the Purchase Price which
would then be in effect if such record date had not been fixed.

     (c) In case the Company shall fix a record date for the making of a
distribution to all holders of the Preferred Shares (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
or assets (other than a regular quarterly cash dividend or a dividend payable in
Preferred Shares) or subscription rights or warrants (excluding those referred
to in Section 11(b) hereof), the Purchase Price to be in effect after such
record date shall be determined by multiplying the Purchase Price in effect
immediately prior to such record date by a fraction, the numerator of which
shall be the then current per share market

                                       10

<PAGE>

price of the Preferred Shares on such record date, less the fair market value
(as determined in good faith by the Board of Directors of the Company, whose
determination shall be described in a statement filed with the Rights Agent) of
the portion of the assets or evidences of indebtedness so to be distributed or
of such subscription rights or warrants applicable to one Preferred Share and
the denominator of which shall be such current per share market price of the
Preferred Shares; provided, however, that in no event shall the consideration to
be paid upon the exercise of one Right be less than the aggregate par value of
the shares of capital stock of the Company to be issued upon exercise of one
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 Purchase
Price shall again be adjusted to be the Purchase Price which would then be in
effect if such record date had not been fixed.

     (d) (i) For the purpose of any computation hereunder, the "current per
share market price" of any security (a "Security" for the purpose of this
Section 11(d)(i)) on any date shall be deemed to be the average of the daily
closing prices per share of such 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 current per share market price of the
Security is determined during a period following the announcement by the issuer
of such Security of (A) a dividend or distribution on such Security payable in
shares of such Security or securities convertible into such shares, or (B) any
subdivision, combination or reclassification of such Security and prior to the
expiration of 30 Trading Days 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 current per share market
price shall be appropriately adjusted to reflect the current market price per
share equivalent of such Security. 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 Security is 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 the Security is listed or admitted to trading or, if the Security is
not listed or admitted to trading on any national securities exchange, the last
quoted price or, if not so quoted, the average of the high bid and low asked
prices in the over-the-counter market, as reported by the National Association
of Securities Dealers, Inc. Automated Quotations System ("NASDAQ") or such other
system then in use, or, if on any such date the Security is not 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 the Security selected by the
Board of Directors of the Company. The term "Trading Day" shall mean a day on
which the principal national securities exchange on which the Security is listed
or admitted to trading is open for the transaction of business or, if the
Security is not listed or admitted to trading on any national securities
exchange, a Business Day.

     (ii) For the purpose of any computation hereunder, the "current per share
market price" of the Preferred Shares shall be determined in accordance with the
method set forth in Section 11(d)(i). If the Preferred Shares are not publicly
traded, the "current per share
                                       11

<PAGE>

market price" of the Preferred Shares shall be conclusively deemed to be the
current per share market price of the Common Shares as determined pursuant to
Section 11(d)(i) (appropriately adjusted to reflect any stock split, stock
dividend or similar transaction occurring after the date hereof), multiplied by
one hundred. If neither the Common Shares nor the Preferred Shares are publicly
held or so listed or traded, "current per share market price" shall mean the
fair value per share as determined in good faith by the Board of Directors of
the Company, whose determination shall be described in a statement filed with
the Rights Agent.

     (e) No adjustment in the Purchase Price shall be required unless such
adjustment would require an increase or decrease of at least 1% in the Purchase
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 one one-millionth of a
Preferred Share or one ten- thousandth of any other share or security as the
case may be. 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 years from the date of the transaction which requires such
adjustment or (ii) the date of the expiration of the right to exercise any
Rights.

     (f) If as a result of an adjustment made pursuant to 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 Shares,
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 Shares contained in Section 11(a) through (c), inclusive, and the
provisions of Sections 7, 9, 10 and 13 with respect to the Preferred Shares
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 Purchase Price hereunder shall evidence the right to
purchase, at the adjusted Purchase Price, the number of one one-hundredths of a
Preferred Share 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 Purchase Price as a result of the
calculations made in Sections 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 Purchase Price, that number of one one-hundredths of a
Preferred Share (calculated to the nearest one one-millionth of a Preferred
Share) obtained by (i) multiplying (x) the number of one one-hundredths of a
share covered by a Right immediately prior to this adjustment by (y) the
Purchase Price in effect immediately prior to such adjustment of the Purchase
Price and (ii) dividing the product so obtained by the Purchase Price in effect
immediately after such adjustment of the Purchase Price.

                                       12

<PAGE>

     (i) The Company may elect on or after the date of any adjustment of the
Purchase Price to adjust the number of Rights, in substitution for any
adjustment in the number of one one-hundredths of a Preferred Share purchasable
upon the exercise of a Right. Each of the Rights outstanding after such
adjustment of the number of Rights shall be exercisable for the number of one
one-hundredths of a Preferred Share 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 ten-thousandth) obtained by dividing the Purchase
Price in effect immediately prior to adjustment of the Purchase Price by the
Purchase Price in effect immediately after adjustment of the Purchase 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 Purchase Price is adjusted or any day thereafter, but, if the Right
Certificates have been issued, shall be at least 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 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 Purchase Price or the
number of one one-hundredths of a Preferred Share issuable upon the exercise of
the Rights, the Right Certificates theretofore and thereafter issued may
continue to express the Purchase Price and the number of one one-hundredths of a
Preferred Share which were expressed in the initial Right Certificates issued
hereunder.

     (k) Before taking any action that would cause an adjustment reducing the
Purchase Price below one one-hundredth of the then par value, if any, of the
Preferred Shares 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 Preferred Shares at such adjusted Purchase Price.

     (l) In any case in which this Section 11 shall require that an adjustment
in the Purchase 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 of the
Preferred Shares and other capital stock or securities of the Company, if any,
issuable upon such exercise over and above the Preferred Shares and other
capital stock or securities of the Company, if any, issuable upon such exercise
on the

                                       13

<PAGE>

basis of the Purchase 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 Purchase 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 Shares, issuance
wholly for cash of any Preferred Shares at less than the current market price,
issuance wholly for cash of Preferred Shares or securities which by their terms
are convertible into or exchangeable for Preferred Shares, dividends on
Preferred Shares payable in Preferred Shares or issuance of rights, options or
warrants referred to hereinabove in Section 11(b), hereafter made by the Company
to holders of its Preferred Shares shall not be taxable to such stockholders.

     (n) In the event that at any time after the date of this Agreement and
prior to the Distribution Date, the Company shall (i) declare or pay any
dividend on the Common Shares payable in Common Shares or (ii) effect a
subdivision, combination or consolidation of the Common Shares (by
reclassification or otherwise than by payment of dividends in Common Shares)
into a greater or lesser number of Common Shares, then in any such case (A) the
number of one one-hundredths of a Preferred Share purchasable after such event
upon proper exercise of each Right shall be determined by multiplying the number
of one one-hundredths of a Preferred Share so purchasable immediately prior to
such event by a fraction, the numerator of which is the number of Common Shares
outstanding immediately before such event and the denominator of which is the
number of Common Shares outstanding immediately after such event, and (B) each
Common Share outstanding immediately after such event shall have issued with
respect to it that number of Rights which each Common Share outstanding
immediately prior to such event had issued with respect to it. The adjustments
provided for in this Section 11(n) shall be made successively whenever such a
dividend is declared or paid or such a subdivision, combination or consolidation
is effected.

     Section 12. Certificate of Adjusted Purchase Price or Number of Shares.
Whenever an adjustment is made as provided in Section 11 or 13 hereof, the
Company shall promptly (a) prepare a certificate setting forth such adjustment,
and a brief statement of the facts accounting for such adjustment, (b) file with
the Rights Agent and with each transfer agent for the Common Shares or the
Preferred Shares a copy of such certificate and (c) mail a brief summary thereof
to each holder of a Right Certificate in accordance with Section 25 hereof.

Section 13. Consolidation, Merger or Sale or Transfer of Assets or Earning
Power. In the event, directly or indirectly, at any time after a Person has
become an Acquiring Person, (a) the Company shall consolidate with, or merge
with and into, any other Person, (b) any Person 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

                                       14

<PAGE>

connection with such merger, all or part of the Common Shares shall be changed
into or exchanged for stock or other securities of any other Person (or the
Company) or cash or any other property, or (c) the Company shall sell or
otherwise transfer (or one or more of its Subsidiaries shall sell or otherwise
transfer), in one or more transactions, assets or earning power aggregating 50%
or more of the assets or earning power of the Company and its Subsidiaries
(taken as a whole) to any other Person other than the Company or one or more of
its wholly-owned Subsidiaries, then, and in each such case, proper provision
shall be made so that (i) each holder of a Right (except as otherwise provided
herein) shall thereafter have the right to receive, upon the exercise thereof at
a price equal to the then current Purchase Price multiplied by the number of one
one-hundredths of a Preferred Share for which a Right is then exercisable, in
accordance with the terms of this Agreement and in lieu of Preferred Shares,
such number of Common Shares of such other Person (including the Company as
successor thereto or as the surviving corporation) as shall equal the result
obtained by (A) multiplying the then current Purchase Price by the number of one
one-hundredths of a Preferred Share for which a Right is then exercisable and
dividing that product by (B) 50% of the then current per share market price of
the Common Shares of such other Person (determined pursuant to Section 11(d)
hereof) on the date of consummation of such consolidation, merger, sale or
transfer; (ii) the issuer of such Common Shares shall thereafter be liable for,
and shall assume, by virtue of such consolidation, merger, sale or transfer, all
the obligations and duties of the Company pursuant to this Agreement; (iii) the
term "Company" shall thereafter be deemed to refer to such issuer; and (iv) such
issuer shall take such steps (including, but not limited to, the reservation of
a sufficient number of its Common Shares in accordance with Section 9 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 the Common Shares thereafter deliverable upon the exercise of
the Rights. The Company shall not consummate any such consolidation, merger,
sale or transfer unless prior thereto the Company and such issuer shall have
executed and delivered to the Rights Agent a supplemental agreement so
providing. The Company shall not enter into any transaction of the kind referred
to in this Section 13 if at the time of such transaction there are any rights,
warrants, instruments or securities outstanding or any agreements or
arrangements which, as a result of the consummation of such transaction, would
eliminate or substantially diminish the benefits intended to be afforded by the
Rights. 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 or to distribute Right Certificates
which evidence fractional Rights. In lieu of such fractional Rights, there shall
be paid to the registered 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 current market value of a whole Right. For the purposes
of this Section 14(a), the current market value of a whole Right shall be the
closing price of the Rights for the Trading Day immediately prior to the date on
which such fractional Rights would have been otherwise issuable. The closing
price for any 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

                                       15

<PAGE>

admitted to trading on the New York Stock Exchange or, if the Rights 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 the Rights are
listed or admitted to trading or, if the Rights are not listed or admitted to
trading on any national securities exchange, the last quoted price or, if not so
quoted, the average of the 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 the Rights are not 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 the Rights selected by the Board of Directors of the Company. If on
any such date no such market maker is making a market in the Rights, the fair
value of the Rights on such date as determined in good faith by the Board of
Directors of the Company shall be used.

                  (b) The Company shall not be required to issue fractions of
Preferred Shares (other than fractions which are integral multiples of one
one-hundredth of a Preferred Share) upon exercise of the Rights or to distribute
certificates which evidence fractional Preferred Shares (other than fractions
which are integral multiples of one one-hundredth of a Preferred Share).
Fractions of Preferred Shares in integral multiples of one one-hundredth of a
Preferred Share may, at the election of the Company, be evidenced by depositary
receipts, pursuant to an appropriate agreement between the Company and a
depositary selected by it; provided, that such agreement shall provide that the
holders of such depositary receipts shall have all the rights, privileges and
preferences to which they are entitled as beneficial owners of the Preferred
Shares represented by such depositary receipts. In lieu of fractional Preferred
Shares that are not integral multiples of one one-hundredth of a Preferred
Share, the Company shall 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 current market value of one Preferred Share. For the
purposes of this Section 14(b), the current market value of a Preferred Share
shall be the closing price of a Preferred Share (as determined pursuant to the
second sentence of Section 11(d)(i) hereof) for the Trading Day immediately
prior to the date of such exercise.

     (c) The holder of a Right by the acceptance of the Right expressly waives
his right to receive any fractional Rights or any fractional shares upon
exercise of a Right (except as provided above).

     Section 15. Rights of Action. All rights of action in respect of this
Agreement, excepting the rights of action given to the Rights Agent under
Section 18 hereof, are vested in the respective registered holders of the Right
Certificates (and, prior to the Distribution Date, the registered holders of the
Common Shares); and any registered holder of any Right Certificate (or, prior to
the Distribution Date, of the Common Shares), without the consent of the Rights
Agent or of the holder of any other Right Certificate (or, prior to the
Distribution Date, of the Common Shares), may, in 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 Rights evidenced by such Right Certificate in the manner provided
in such Right Certificate and in this Agreement.

                                       16

<PAGE>

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 will be
entitled to specific performance of the obligations under, and injunctive relief
against actual or threatened violations of the obligations 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, the Rights will be transferable only in
connection with the transfer of the Common Shares;

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

     (c) the Company and the Rights Agent may deem and treat the person in whose
name the Right Certificate (or, prior to the Distribution Date, the associated
Common Shares 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 Shares 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.

     Section 17. Right Certificate Holder Not Deemed a Stockholder. 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 Preferred Shares 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 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 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. The Company agrees to pay to the
Rights Agent reasonable compensation 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 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
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

                                       17

<PAGE>

administration of this Agreement, including the costs and expenses of
defending against any claim of liability in the premises. The indemnification
provided for hereunder shall survive the expiration of the Rights and the
termination of this Agreement . The costs and expenses incurred in enforcing
this right of indemnification (subject to the Rights Agent having acted in
accordance with this Agreement and without negligence, bad faith or willful
misconduct) shall be paid by the Company.

     The Rights Agent may conclusively rely upon, and shall be protected from,
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 the Preferred Shares or
Common Shares or for 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, executed and, where necessary, verified or
acknowledged, by the proper person or persons, or otherwise upon the advice of
counsel as set forth in Section 20 hereof.

     Section 19. Merger or Consolidation or Change of Name of Rights Agent. 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 stock transfer or
corporate trust powers 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 Rights Agent 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.

     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 imposed by this Agreement upon the following terms and
conditions, by all of

                                       18

<PAGE>

which the Company and the holders of Right Certificates, by their acceptance
thereof, shall be bound:

     (a) Before the Rights Agent acts or refrains from acting, it may consult
with legal counsel (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 be
proved or established by the Company prior to taking or suffering any action
hereunder, such fact or matter, including the identity of an Acquiring Person or
any Associate, Affiliate or nominee thereof (unless other evidence in respect
thereof be herein specifically prescribed) may be deemed to be conclusively
proved and established by a certificate signed by any one of the Chairman of the
Board, the Chief Executive Officer, the President, any Vice President, the
Treasurer or the Secretary of the Company and delivered to the Rights Agent; and
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 to the Company and any other
Person only for its own 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 11(a)(ii) hereof) or any adjustment in
the terms of the Rights (including the manner, method or amount thereof)
provided for in Section 3, 11, 13, 23 or 24, or the ascertaining of the
existence of facts that would require any such change or adjustment (except with
respect to the exercise of Rights evidenced by Right Certificates after actual
notice that such change or adjustment is required); nor shall it by any act
hereunder be deemed to make any representation or warranty as to the
authorization or reservation of any Preferred Shares to be issued pursuant to
this Agreement or any Right Certificate or as to whether any Preferred Shares
will, when issued, be validly authorized and issued, fully paid and
nonassessable.

     (f) The Company agrees that it will perform, execute, acknowledge and
deliver or cause to be performed, executed, acknowledged and delivered all such
further and

                                       19


<PAGE>

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 from any
one of the Chairman of the Board, the Vice Chairman, the Chief Executive
Officer, the President, any Vice President, the Secretary or the Treasurer of
the Company, and 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 by it in good faith in accordance with instructions of any such officer
or for any delay in acting while waiting for those instructions.

     (h) The Rights Agent and any stockholder, 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 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, default, neglect or misconduct of any such attorneys or
agents or for any loss to the Company resulting from any such act, default,
neglect or misconduct, provided reasonable care was exercised in the selection
and continued employment thereof.

     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 30 days' notice in writing mailed to the Company and to each transfer agent
of the Common Shares or Preferred Shares by registered or certified mail, and to
the holders of the Right Certificates by first-class mail. The Company may
remove the Rights Agent or any successor Rights Agent upon 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 Shares or Preferred Shares 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 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 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
corporation organized and doing business under the laws of the United States or
of the State of Illinois (or of any other state of the United States so long as
such corporation is authorized to do business as a banking institution in the
State of Illinois, in good standing, having an office in the State of Illinois,
which is authorized under such laws to

                                       20

<PAGE>

exercise corporate trust or stock transfer 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
million. 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 Shares
or Preferred Shares, 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 to reflect any adjustment or change in
the Purchase Price and the number or kind or class of shares or other securities
or property purchasable under the Right Certificates made in accordance with the
provisions of this Agreement.

     Section 23. Redemption. (a) The Board of Directors of the Company may, at
its option, at any time prior to such time as any Person becomes an Acquiring
Person, redeem all but not less than all the then outstanding Rights at a
redemption price of $.01 per Right, appropriately adjusted to reflect any stock
split, stock dividend or similar transaction occurring after the date hereof
(such redemption price being hereinafter referred to as the "Redemption Price").
The redemption of the Rights by the Board of Directors may be made effective at
such time, on such basis and with such conditions as the Board of Directors in
its sole discretion may establish.

     (b) Immediately upon the action of the Board of Directors of the Company
ordering the redemption of the Rights pursuant to paragraph (a) of this Section
23, 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. The Company shall promptly give public
notice of any such redemption; provided, however, that the failure to give, or
any defect in, any such notice shall not affect the validity of such redemption.
Within 10 days after such action of the Board of Directors ordering the
redemption of the Rights, the Company shall mail a notice of redemption to all
the holders of the then outstanding Rights 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 Shares. 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,

                                       21

<PAGE>

acquire or purchase for value any Rights at any time in any manner other than
that specifically set forth in this Section 23 or in Section 24 hereof, and
other than in connection with the purchase of Common Shares prior to the
Distribution Date.

     Section 24. Exchange. (a) The Board of Directors of the Company may, at its
option, at any time after any Person becomes an Acquiring Person, 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 11(a)(ii)
hereof) for Common Shares at an exchange ratio of one Common Share 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 the Company, any Subsidiary of the Company,
any employee benefit plan of the Company or any such Subsidiary, or any entity
holding Common Shares for or pursuant to the terms of any such plan), together
with all Affiliates and Associates of such Person, becomes the Beneficial Owner
of 50% or more of the Common Shares then outstanding.

     (b) Immediately upon the action of the Board of Directors of the Company
ordering the exchange of any Rights pursuant to paragraph (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 Common Shares equal to the number of
such Rights held by such holder multiplied by the Exchange Ratio. The Company
shall promptly give public notice of any such exchange; provided, however, that
the failure to give, or any defect in, such notice shall not affect the validity
of such exchange. The Company promptly shall mail a notice of any such exchange
to all of the holders of such Rights at their last addresses as they appear upon
the registry books of the Rights Agent. Any notice which is mailed in the manner
herein provided shall be deemed given, whether or not the holder receives the
notice. Each such notice of exchange will state the method by which the exchange
of the Common Shares 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 11(a)(ii)
hereof) held by each holder of Rights.

     (c) In the event that there shall not be sufficient Common Shares 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 Common Shares for
issuance upon exchange of the Rights. In the event the Company shall, after good
faith effort, be unable to take all such action as may be necessary to authorize
such additional Common Shares, the Company shall substitute, for each Common
Share that would otherwise be issuable upon exchange of a Right, a number of
Preferred Shares or fraction thereof such that the current per share market
price of one Preferred Share multiplied by such number or fraction is equal to
the current per share market price of one Common Share as of the date of
issuance of such Preferred Shares or fraction thereof.

                                       22

<PAGE>

     (d) The Company shall not be required to issue fractions of Common Shares
or to distribute certificates which evidence fractional Common Shares. In lieu
of such fractional Common Shares, the Company shall pay to the registered
holders of the Right Certificates with regard to which such fractional Common
Shares would otherwise be issuable an amount in cash equal to the same fraction
of the current market value of a whole Common Share. For the purposes of this
paragraph (d), the current market value of a whole Common Share shall be the
closing price of a Common Share (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
(i) to pay any dividend payable in stock of any class to the holders of its
Preferred Shares or to make any other distribution to the holders of its
Preferred Shares (other than a regular quarterly cash dividend), (ii) to offer
to the holders of its Preferred Shares rights or warrants to subscribe for or to
purchase any additional Preferred Shares or shares of stock of any class or any
other securities, rights or options, (iii) to effect any reclassification of its
Preferred Shares (other than a reclassification involving only the subdivision
of outstanding Preferred Shares), (iv) to effect any consolidation or merger
into or with, or to effect any sale or other transfer (or to permit one or more
of its Subsidiaries to effect any sale or other transfer), in one or more
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, (v) to effect the
liquidation, dissolution or winding up of the Company, or (vi) to declare or pay
any dividend on the Common Shares payable in Common Shares or to effect a
subdivision, combination or consolidation of the Common Shares (by
reclassification or otherwise than by payment of dividends in Common Shares),
then, in each such case, the Company shall give to each holder of a Right
Certificate, 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, or 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 Common Shares and/or Preferred Shares, 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 10 days prior to the record date
for determining holders of the Preferred Shares for purposes of such action, and
in the case of any such other action, at least 10 days prior to the date of the
taking of such proposed action or the date of participation therein by the
holders of the Common Shares and/or Preferred Shares, whichever shall be the
earlier.

     (b) In case the event set forth in Section 11(a)(ii) hereof shall occur,
then the Company shall as soon as practicable thereafter give to each holder of
a Right Certificate, in accordance with Section 26 hereof, a notice of the
occurrence of such event, which notice shall describe such event and the
consequences of such 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

                                       23

<PAGE>

Company shall be sufficiently given or made if sent by registered or certified
mail, and deemed given upon receipt, addressed (until another address is filed
in writing with the Rights Agent) as follows:

                           Covance Inc.
                           210 Carnegie Center
                           Princeton, New Jersey 08540
                           Attention:  Corporate Secretary

Subject to the provisions of Section 21 hereof, 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 registered or certified mail, and deemed given upon receipt,
addressed (until another address is filed in writing with the Company) as
follows:

                           Harris Trust and Savings Bank
                           311 West Monroe, 11th Floor
                           P.O. Box 755
                           Chicago, Illinois  60690
                           Attention:  Deborah J. Hokinson

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 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, and deemed received by such party three days after
mailing.

     Section 27. Supplements and Amendments. The Company may from time to time
supplement or amend this Agreement without the approval of any holders of Right
Certificates in order to cure any ambiguity, to correct or supplement any
provision contained herein which may be defective or inconsistent with any other
provisions herein, or to make any other provisions with respect to the Rights
which the Company may deem necessary or desirable, any such supplement or
amendment to be evidenced by a writing signed by the Company and the Rights
Agent; provided, however, that from and after such time as any Person becomes an
Acquiring Person, this Agreement shall not be amended in any manner which would
adversely affect the interests of the holders of Rights.

     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. 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

                                       24

<PAGE>

the registered holders of the Right Certificates (and, prior to the Distribution
Date, the Common Shares) 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, the Common Shares).

     Section 30. 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.

     Section 31. Governing Law. This Agreement 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 performed
entirely within such State.

     Section 32. 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 33. 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.

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

Attest:                                  COVANCE INC.

By:                                      By:
   --------------------------               -----------------------------
   Title:                                   Title:

Attest:                                  HARRIS TRUST AND SAVINGS BANK

By:                                      By:
   --------------------------               -----------------------------
   Title:                                   Title:

                                       25

<PAGE>


                                                                       Exhibit A

Form of Right Certificate

Certificate No. R-                               Rights

     NOT EXERCISABLE AFTER DECEMBER 31, 2006 OR EARLIER IF REDEMPTION OR
     EXCHANGE OCCURS. THE RIGHTS ARE SUBJECT TO REDEMPTION AT $.01 PER RIGHT AND
     TO EXCHANGE ON THE TERMS SET FORTH IN THE RIGHTS AGREEMENT.

                                Right Certificate

                                  COVANCE 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 Rights
Agreement, dated as of December 31, 1996 (the "Rights Agreement"), between
Covance Inc., a Delaware corporation (the "Company"), and Harris Trust and
Savings Bank (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 5:00 P.M., New York time, on December 31, 2006 at the principal
office of the Rights Agent, or at the office of its successor as Rights Agent,
one one-hundredth of a fully paid non-assessable share of Series A Junior
Participating Preferred Stock, par value $1.00 per share (the "Preferred
Shares"), of the Company, at a purchase price of $100 per one one-hundredth of a
Preferred Share (the "Purchase Price"), upon presentation and surrender of this
Right Certificate with the Form of Election to Purchase duly executed. The
number of Rights evidenced by this Right Certificate (and the number of one
one-hundredths of a Preferred Share which may be purchased upon exercise hereof)
set forth above, and the Purchase Price set forth above, are the number and
Purchase Price as of December 31, 1996, based on the Preferred Shares as
constituted at such date. As provided in the Rights Agreement, the Purchase
Price and the number of one one-hundredths of a Preferred Share 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. Copies of
the Rights Agreement are on file at the principal executive offices of the
Company and the above-mentioned offices of the Rights Agent.

<PAGE>

     This Right Certificate, with or without other Right Certificates, upon
surrender at the principal office of the Rights Agent, may be exchanged for
another Right Certificate or Right Certificates of like tenor and date
evidencing Rights entitling the holder to purchase a like aggregate number of
Preferred Shares as the Rights evidenced by the Right Certificate or Right
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 Right Certificates
for the number of whole Rights not exercised.

     Subject to the provisions of the Rights Agreement, the Rights evidenced by
this Certificate (i) may be redeemed by the Company at a redemption price of
$.01 per Right or (ii) may be exchanged in whole or in part for Preferred Shares
or shares of the Company's Common Stock, no par value.

     No fractional Preferred Shares will be issued upon the exercise of any
Right or Rights evidenced hereby (other than fractions which are integral
multiples of one one-hundredth of a Preferred Share, which may, at the election
of the Company, be evidenced by depositary receipts), but in lieu thereof a cash
payment will be made, as provided in the Rights Agreement.

     No holder of this Right Certificate shall be entitled to vote or receive
dividends or be deemed for any purpose the holder of the Preferred Shares or of
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 the Rights Agent.

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

ATTEST:                           COVANCE INC.

                                  By
---------------------------       -------------------------------    
Name:                             Name:
Title:                            Title:

                                      A-2

<PAGE>

Countersigned:

HARRIS TRUST AND SAVINGS BANK

By
   ------------------------
   Name:
   Title:

                                       A-3

<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:

                  Signatures must be guaranteed by a member firm of a registered
national securities exchange, a member of the National Association of Securities
Dealers, Inc., or a commercial bank or trust company having an office or
correspondent in the United States.

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

                  The undersigned hereby certifies that the Rights evidenced by
this Right Certificate are not beneficially owned by an Acquiring Person or an
Affiliate or Associate thereof (as defined in the Rights Agreement).

                                    Signature

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

                                      A-4

<PAGE>


             Form of Reverse Side of Right Certificate -- continued

                          FORM OF ELECTION TO PURCHASE

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

To:  COVANCE INC.

   
                The undersigned hereby irrevocably elects to exercise __________
Rights represented by this Right Certificate to purchase the Preferred Shares
issuable upon the exercise of such Rights and requests that certificates for
such Preferred Shares be issued in the name of:
    

Please insert social security
or other identifying number

                         (Please print name and address)

If such number of Rights shall not be all the Rights evidenced by this Right
Certificate, a new Right Certificate for the balance remaining of such Rights
shall be registered in the name of and delivered to:

Please insert social security
or other identifying number

                         (Please print name and address)

Dated:

                                    Signature

Signature Guaranteed:

                Signatures must be guaranteed by a member firm of a registered
national securities exchange, a member of the National Association of Securities
Dealers, Inc., or a commercial bank or trust company having an office or
correspondent in the United States.

                                      A-5

<PAGE>



             Form of Reverse Side of Right Certificate -- continued

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

                The undersigned hereby certifies that the Rights evidenced by
this Right Certificate are not beneficially owned by an Acquiring Person or an
Affiliate or Associate thereof (as defined in the Rights Agreement).

                                    Signature

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



NOTICE

     The signature in the Form of Assignment or Form of Election to Purchase, as
the case may be, must conform to the name as written upon the face of this Right
Certificate in every particular, without alteration or enlargement or any change
whatsoever.

     In the event the certification set forth above in the Form of Assignment or
the Form of Election to Purchase, as the case may be, is not completed, the
Company and the Rights Agent will deem the beneficial owner of the Rights
evidenced by this Right Certificate to be an Acquiring Person or an Affiliate or
Associate thereof (as defined in the Rights Agreement) and such Assignment or
Election to Purchase will not be honored.

   
                                      A-6
    

<PAGE>

   
                                                                       Exhibit B
    

                          SUMMARY OF RIGHTS TO PURCHASE

                                PREFERRED SHARES

     On December 3, 1996, the Board of Directors of Covance Inc. (the "Company")
declared a dividend of one preferred share purchase right (a "Right") for each
outstanding share of common stock, par value $.50 per share (the "Common
Shares"), of the Company. The dividend is payable on December 31, 1996 (the
"Record Date") to the stockholders of record on that date. Each Right entitles
the registered holder to purchase

                                      B-1

<PAGE>

from the Company one one-hundredth of a share of Series A Junior Participating
Preferred Stock, par value $1.00 per share (the "Preferred Shares"), of the
Company at a price of $100 per one one-hundredth of a Preferred Share (the
"Purchase Price"), subject to adjustment. The description and terms of the
Rights are set forth in a Rights Agreement (the "Rights Agreement") between the
Company and Harris Trust and Savings Bank, as Rights Agent (the "Rights Agent").

     Until the earlier to occur of (i) 10 days following a public announcement
that a person or group of affiliated or associated persons (an "Acquiring
Person") have acquired beneficial ownership of 20% or more of the outstanding
Common Shares or (ii) 10 business days (or such later date as may be determined
by action of the Board of Directors prior to such time as any person or group of
affiliated persons becomes an Acquiring Person) following the commencement of,
or announcement of an intention to make, a tender offer or exchange offer the
consummation of which would result in the beneficial ownership by a person or
group of 20% or more of the outstanding Common Shares (the earlier of such dates
being called the "Distribution Date"), the Rights will be evidenced, with
respect to any of the Common Share certificates outstanding as of the Record
Date, by such Common Share certificate with a copy of this Summary of Rights
attached thereto.

     The Rights Agreement provides that, until the Distribution Date (or earlier
redemption or expiration of the Rights), the Rights will be transferred with and
only with the Common Shares. Until the Distribution Date (or earlier redemption
or expiration of the Rights), new Common Share certificates issued after the
Record Date upon transfer or new issuance of Common Shares will contain a
notation incorporating the Rights Agreement by reference. Until the Distribution
Date (or earlier redemption or expiration of the Rights), the surrender for
transfer of any certificates for Common Shares outstanding as of the Record
Date, even without such notation or a copy of this Summary of Rights being
attached thereto, will also constitute the transfer of the Rights associated
with the Common Shares represented by such certificate. As soon as practicable
following the Distribution Date, separate certificates evidencing the Rights
("Right Certificates") will be mailed to holders of record of the Common Shares
as of the close of business on the Distribution Date and such separate Right
Certificates alone will evidence the Rights.

     The Rights are not exercisable until the Distribution Date. The Rights will
expire on December 31, 2006 (the "Final Expiration Date"), unless the Final
Expiration Date is extended or unless the Rights are earlier redeemed or
exchanged by the Company, in each case, as described below.

     The Purchase Price payable, and the number of Preferred Shares or other
securities or property issuable, upon exercise of the Rights are subject to
adjustment from time to time to prevent dilution (i) in the event of a stock
dividend on, or a subdivision, combination or reclassification of, the Preferred
Shares, (ii) upon the grant to holders of the Preferred Shares of certain rights
or warrants to subscribe for or purchase Preferred Shares at a price, or
securities convertible into Preferred Shares with a conversion price, less than
the then-current market price of the Preferred Shares or (iii) upon the
distribution to holders

   
                                      B-2
    

<PAGE>

of the Preferred Shares of evidences of indebtedness or assets (excluding
regular periodic cash dividends paid out of earnings or retained earnings or
dividends payable in Preferred Shares) or of subscription rights or warrants
(other than those referred to above).

     The number of outstanding Rights and the number of one one-hundredths of a
Preferred Share issuable upon exercise of each Right are also subject to
adjustment in the event of a stock split of the Common Shares or a stock
dividend on the Common Shares payable in Common Shares or subdivisions,
consolidations or combinations of the Common Shares occurring, in any such case,
prior to the Distribution Date.

     Preferred Shares purchasable upon exercise of the Rights will not be
redeemable. Each Preferred Share will be entitled to a minimum preferential
quarterly dividend payment of $10 per share but will be entitled to an aggregate
dividend of 100 times the dividend declared per Common Share. In the event of
liquidation, the holders of the Preferred Shares will be entitled to a minimum
preferential liquidation payment of $100 per share but will be entitled to an
aggregate payment of 100 times the payment made per Common Share. Each Preferred
Share will have 100 votes, voting together with the Common Shares. Finally, in
the event of any merger, consolidation or other transaction in which Common
Shares are exchanged, each Preferred Share will be entitled to receive 100 times
the amount received per Common Share. These rights are protected by customary
antidilution provisions.

     Because of the nature of the Preferred Shares' dividend, liquidation and
voting rights, the value of the one one-hundredth interest in a Preferred Share
purchasable upon exercise of each Right should approximate the value of one
Common Share.

     In the event that the Company is acquired in a merger or other business
combination transaction or 50% or more of its consolidated assets or earning
power are sold after a person or group has become an Acquiring Person, proper
provision will be made so that each holder of a Right will thereafter have the
right to receive, upon the exercise thereof at the then current exercise price
of the Right, that number of shares of common stock of the acquiring company
which at the time of such transaction will have a market value of two times the
exercise price of the Right. In the event that any person or group of affiliated
or associated persons becomes an Acquiring Person, proper provision shall be
made so that each holder of a Right, other than Rights beneficially owned by the
Acquiring Person (which will thereafter be void), will thereafter have the right
to receive upon exercise that number of Common Shares having a market value of
two times the exercise price of the Right.

     At any time after any person or group becomes an Acquiring Person and prior
to the acquisition by such person or group of 50% or more of the outstanding
Common Shares, the Board of Directors of the Company may exchange the Rights
(other than Rights owned by such person or group which will have become void),
in whole or in part, at an exchange ratio of one Common Share, or one
one-hundredth of a Preferred

   
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<PAGE>

Share (or of a share of a class or series of the Company's preferred stock
having equivalent rights, preferences and privileges), per Right (subject to
adjustment).

     With certain exceptions, no adjustment in the Purchase Price will be
required until cumulative adjustments require an adjustment of at least 1% in
such Purchase Price. No fractional Preferred Shares will be issued (other than
fractions which are integral multiples of one one-hundredth of a Preferred
Share, which may, at the election of the Company, be evidenced by depositary
receipts) and in lieu thereof, an adjustment in cash will be made based on the
market price of the Preferred Shares on the last trading day prior to the date
of exercise.

     At any time prior to the acquisition by a person or group of affiliated or
associated persons of beneficial ownership of 20% or more of the outstanding
Common Shares, the Board of Directors of the Company may redeem the Rights in
whole, but not in part, at a price of $.01 per Right (the "Redemption Price").
The redemption of the Rights may be made effective at such time on such basis
with such conditions as the Board of Directors in its sole discretion may
establish. Immediately upon any redemption of the Rights, the right to exercise
the Rights will terminate and the only right of the holders of Rights will be to
receive the Redemption Price.

     The terms of the Rights may be amended by the Board of Directors of the
Company without the consent of the holders of the Rights, except that from and
after such time as any person or group of affiliated or associated persons
becomes an Acquiring Person no such amendment may adversely affect the interests
of the holders of the Rights.

     Until a Right is exercised, the holder thereof, as such, will have no
rights as a stockholder of the Company, including, without limitation, the right
to vote or to receive dividends.

     A copy of the Rights Agreement has been filed with the Securities and
Exchange Commission as an Exhibit to a Registration Statement on Form 10 dated
November 26, 1996. A copy of the Rights Agreement is available free of charge
from the Company. This summary description of the Rights does not purport to be
complete and is qualified in its entirety by reference to the Rights Agreement,
which is hereby incorporated herein by reference.

   
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