<PAGE>   1



                               CRITICAL PATH, INC.

                                       AND

                        COMPUTERSHARE TRUST COMPANY, INC.

                                  RIGHTS AGENT









                        PREFERRED STOCK RIGHTS AGREEMENT

                           DATED AS OF MARCH 19, 2001


<PAGE>   2

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                            PAGE
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<S>                                                                                         <C>
Section 1.  Certain Definitions...............................................................1

Section 2.  Appointment of Rights Agent.......................................................7

Section 3.  Issuance of Rights Certificates...................................................7

Section 4.  Form of Rights Certificates.......................................................9

Section 5.  Countersignature and Registration................................................10

Section 6.  Transfer, Split Up, Combination and Exchange of Rights Certificates;
            Mutilated, Destroyed, Lost or Stolen Rights Certificates.........................10

Section 7.  Exercise of Rights; Exercise Price; Expiration Date of Rights....................11

Section 8.  Cancellation and Destruction of Rights Certificates..............................13

Section 9.  Reservation and Availability of Preferred Shares.................................13

Section 10. Record Date......................................................................14

Section 11. Adjustment of Exercise Price, Number of Shares or Number of Rights...............15

Section 12. Certificate of Adjusted Exercise Price or Number of Shares.......................21

Section 13. Consolidation, Merger or Sale or Transfer of Assets or Earning Power.............21

Section 14. Fractional Rights and Fractional Shares..........................................25

Section 15. Rights of Action.................................................................26

Section 16. Agreement of Rights Holders......................................................27

Section 17. Rights Certificate Holder Not Deemed a Stockholder...............................27

Section 18. Concerning the Rights Agent......................................................27

Section 19. Merger or Consolidation or Change of Name of Rights Agent........................28

Section 20. Duties of Rights Agent...........................................................28

Section 21. Change of Rights Agent...........................................................30

Section 22. Issuance of New Rights Certificates..............................................31
</TABLE>


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<PAGE>   3

                                TABLE OF CONTENTS
                                  (CONTINUED)

<TABLE>
<CAPTION>
                                                                                            PAGE
                                                                                            ----
<S>                                                                                         <C>
Section 23. Redemption.......................................................................32

Section 24. Exchange.........................................................................32

Section 25. Notice of Certain Events.........................................................34

Section 26. Notices..........................................................................34

Section 27. Supplements and Amendments.......................................................35

Section 28. Successors.......................................................................36

Section 29. Determinations and Actions by the Board of Directors, etc........................36

Section 30. Benefits of this Agreement.......................................................36

Section 31. Severability.....................................................................36

Section 32. Governing Law....................................................................37

Section 33. Counterparts.....................................................................37

Section 34. Descriptive Headings.............................................................37
</TABLE>


EXHIBITS

Exhibit A      Form of Certificate of Designation

Exhibit B      Form of Rights Certificate

Exhibit C      Summary of Rights


                                     -iii-
<PAGE>   4

                        PREFERRED STOCK RIGHTS AGREEMENT



       This Preferred Stock Rights Agreement, is dated as of March 19, 2001,
between Critical Path, Inc., a California corporation, and Computershare Trust
Company, Inc.

       On March 19, 2001 (the "RIGHTS DIVIDEND DECLARATION DATE"), the Board of
Directors of the Company (i) authorized and declared a dividend of one Preferred
Share Purchase Right (a "RIGHT") for each Common Share of the Company (as
hereinafter defined) outstanding as of the Close of Business (as hereinafter
defined) on May 15, 2001 (the "RECORD DATE") and (ii) authorized the issuance to
each holder of Exchangeable Shares as of the Close of Business on the Record
Date of one Right for each Exchangeable Share so held, each Right representing
the right to purchase one one-thousandth (0.001) of a share of Series C
Participating Preferred Stock (as such number may be adjusted pursuant to the
provisions of this Agreement), having the rights, preferences and privileges set
forth in the form of Certificate of Designations of Rights, Preferences and
Privileges of Series C Participating Preferred Stock attached hereto as Exhibit
A, upon the terms and subject to the conditions herein set forth, and further
authorized and directed the issuance of one Right (as such number may be
adjusted pursuant to the provisions of this Agreement) with respect to each
Common Share or Exchangeable Share that shall become outstanding between the
Record Date and the earlier of the Distribution Date and the Expiration Date (as
such terms are hereinafter defined), and in certain circumstances after the
Distribution Date.

       NOW, THEREFORE, in consideration of the promises 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, who or which,
together with all Affiliates and Associates of such Person, shall be the
Beneficial Owner of 15% or more of the Common Shares of the Company then
outstanding, but shall not include the Company, any Subsidiary of the Company or
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.
Notwithstanding the foregoing, no Person shall be deemed to be 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 15% or more of the Common Shares of
the Company then outstanding; provided, however, that if a Person shall become
the Beneficial Owner of 15% 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 (other than pursuant to a dividend or distribution
paid or made by (i) the Company on the outstanding Common Shares in Common
Shares or pursuant to a split or subdivision of the outstanding Common Shares or
(ii) Exchangeco on the outstanding Exchangeable Shares in Exchangeable Shares or
pursuant to a split or subdivision of the outstanding Exchangeable Shares),


<PAGE>   5

then such Person shall be deemed to be an Acquiring Person unless upon becoming
the Beneficial Owner of such additional Common Shares of the Company such Person
does not beneficially own 15% or more of the Common Shares of the Company then
outstanding. Notwithstanding the foregoing, (i) if the Company's Board of
Directors 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 (including, without limitation,
because (A) such Person was unaware that it beneficially owned a percentage of
the Common Shares of the Company that would otherwise cause such Person to be an
"Acquiring Person," as defined pursuant to the foregoing provisions of this
paragraph (a), or (B) such Person was aware of the extent of the Common Shares
of the Company it beneficially owned but had no actual knowledge of the
consequences of such beneficial ownership under this Agreement) and without any
intention of changing or influencing control of the Company, and if such Person
divested or 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 or to have become an "Acquiring Person" for any
purposes of this Agreement; and (ii) if, as of the date hereof, any Person is
the Beneficial Owner of 15% or more of the Common Shares of the Company
outstanding, such Person shall not be or become an "Acquiring Person," as
defined pursuant to the foregoing provisions of this paragraph (a), unless and
until such time as such Person shall become the Beneficial Owner of additional
Common Shares of the Company (other than pursuant to a dividend or distribution
paid or made by (i) the Company on the outstanding Common Shares in Common
Shares or pursuant to a split or subdivision of the outstanding Common Shares or
(ii) Exchangeco on the outstanding Exchangeable Shares in Exchangeable Shares or
pursuant to a split or subdivision of the outstanding Exchangeable Shares),
unless, upon becoming the Beneficial Owner of such additional Common Shares of
the Company, such Person is not then the Beneficial Owner of 15% or more of the
Common Shares of the Company then outstanding.

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

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

              (d) 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, for purposes of Section
13(d) of the Exchange Act and Rule 13d-3 thereunder (or any comparable or
successor law or regulation);

                     (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


                                      -2-
<PAGE>   6

offering of securities), or upon the exercise of conversion rights, exchange
rights, rights (other than the Rights), warrants or options, or otherwise
(including, without limitation, upon the exchange of Exchangeable Shares);
provided, however, that a Person shall not be deemed pursuant to this Section
1(d)(ii)(A) to be the Beneficial Owner of, or to beneficially own, (1)
securities tendered pursuant to a tender or exchange offer made by or on behalf
of such Person or any of such Person's Affiliates or Associates until such
tendered securities are accepted for purchase or exchange, or (2) securities
which a Person or any of such Person's Affiliates or Associates may be deemed to
have the right to acquire pursuant to any merger or other acquisition agreement
between the Company and such Person (or one or more of its Affiliates or
Associates) if such agreement has been approved by the Board of Directors of the
Company prior to there being an Acquiring Person; 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 under this Section 1(d)(ii)(B) 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 of 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 (or any Affiliate or Associate thereof) with which such
Person or any of such Person's Affiliates or Associates has any agreement,
arrangement or understanding, whether or not in writing (other than customary
agreements with and between underwriters and selling group members with respect
to a bona fide public offering of securities) for the purpose of acquiring,
holding, voting (except to the extent contemplated by the proviso to Section
1(d)(ii)(B)) or disposing of any securities of the Company; provided, however,
that in no case shall an officer or director of the Company be deemed (x) the
Beneficial Owner of any securities beneficially owned by another officer or
director of the Company solely by reason of actions undertaken by such persons
in their capacity as officers or directors of the Company or (y) the Beneficial
Owner of securities held of record by the trustee of any employee benefit plan
of the Company or any Subsidiary of the Company for the benefit of any employee
of the Company or any Subsidiary of the Company, other than the officer or
director, by reason of any influence that such officer or director may have over
the voting of the securities held in the plan.

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

              (f) "CLOSE OF BUSINESS" on any given date shall mean 5:00 P.M.,
New York time, on such date; provided, however, that if such date is not a
Business Day it shall mean 5:00 P.M., New York time, on the next succeeding
Business Day.

              (g) "COMMON SHARES" when used with reference to the Company shall
mean the shares of Common Stock of the Company, par value $0.001 per share, and
the Exchangeable Shares. "COMMON SHARES OF THE COMPANY" shall mean only the
shares of Common Stock of the Company, par value $0.001 per share, and not the
Exchangeable Shares. "COMMON SHARES," when used with


                                      -3-
<PAGE>   7

reference to any Person other than the Company or Exchangeco 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.

              (h) "COMMON STOCK EQUIVALENTS" shall have the meaning set forth in
Section 11(a)(iii) hereof.

              (i) "COMPANY" shall mean Critical Path, Inc., a California
corporation, subject to the terms of Section 13(a)(iii)(C) hereof.

              (j) "CURRENT PER SHARE MARKET PRICE" of any security (a "Security"
for purposes of this definition), for all computations other than those made
pursuant to Section 11(a)(iii) hereof, shall mean the average of the daily
closing prices per share of such Security for the thirty (30) consecutive
Trading Days immediately prior to such date, and for purposes of computations
made pursuant to Section 11(a)(iii) hereof, the Current Per Share Market Price
of any Security on any date shall be deemed to be the average of the daily
closing prices per share of such Security for the ten (10) consecutive Trading
Days 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 (i) a dividend or
distribution on such Security payable in shares of such Security or securities
convertible into such shares or (ii) any subdivision, combination or
reclassification of such Security, and prior to the expiration of the applicable
thirty (30) Trading Day or ten (10) Trading Day period, after the ex-dividend
date for such dividend or distribution, or the record date for such subdivision,
combination or reclassification, then, and in each such case, the 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 sale price or, if such last sale price is not reported, 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
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. If on any such
date no market maker is making a market in the Security, the fair value of such
shares on such date as determined in good faith by the Board of Directors of the
Company shall be used. If the Preferred Shares are not publicly traded, the
Current Per Share Market Price of the Preferred Shares shall be conclusively
deemed to be the product of (x) the Current Per Share Market Price of the Common
Shares of the Company as determined pursuant to this Section 1(j), as
appropriately adjusted to reflect any stock split, stock dividend or similar
transaction occurring after the date hereof, multiplied by (y) 1000. If the
Security is not publicly held or so listed or traded, Current Per Share Market
Price shall mean the


                                      -4-
<PAGE>   8

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 and shall be conclusive for all purposes.

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

              (l) "DISTRIBUTION DATE" shall mean the earlier of (i) the Close of
Business on the tenth day (or such later date as may be determined by action of
the Company's Board of Directors) after the Shares Acquisition Date (or, if the
tenth day after the Shares Acquisition Date occurs before the Record Date, the
Close of Business on the Record Date) or (ii) the Close of Business on the tenth
Business Day (or such later date as may be determined by action of the Company's
Board of Directors) after the date that a tender or exchange offer 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 Person or entity
organized, appointed or established by the Company for or pursuant to the terms
of any such plan) is first published or sent or given within the meaning of Rule
14d-2(a) of the General Rules and Regulations under the Exchange Act, if,
assuming the successful consummation thereof, such Person would be an Acquiring
Person.

              (m) "EQUIVALENT SHARES" shall mean Preferred Shares and any other
class or series of capital stock of the Company which is entitled to the same
rights, privileges and preferences as the Preferred Shares.

              (n) "EXCHANGE ACT" shall mean the Securities Exchange Act of 1934,
as amended.

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

              (p) "EXCHANGEABLE SHARES" shall mean the Class A Non-Voting
Preference Shares of Exchangeco, each of which is exchangeable for one Common
Share of the Company.

              (q) "EXCHANGECO" shall mean Critical Path Messaging Co., an
unlimited liability company existing under the laws of the Province of Nova
Scotia and a subsidiary of the Company.

              (r) "EXERCISE PRICE" shall have the meaning set forth in Section
4(a) hereof.

              (s) "EXPIRATION DATE" shall mean the earliest to occur of: (i) the
Close of Business on the Final Expiration Date, (ii) the Redemption Date, or
(iii) the time at which the Board of Directors orders the exchange of the Rights
as provided in Section 24 hereof.

              (t) "FINAL EXPIRATION DATE" shall mean May 15, 2011.

              (u) "NASDAQ" shall mean the National Association of Securities
Dealers, Inc. Automated Quotations System.

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


                                      -5-
<PAGE>   9

              (w) "POST-EVENT TRANSFEREE" shall have the meaning set forth in
Section 7(e) hereof.

              (x) "PREFERRED SHARES" shall mean shares of Series C Participating
Preferred Stock, par value $0.001 per share, of the Company.

              (y) "PRE-EVENT TRANSFEREE" shall have the meaning set forth in
Section 7(e) hereof.

              (z) "PRINCIPAL PARTY" shall have the meaning set forth in Section
13(b) hereof.

              (aa) "RECORD DATE" shall have the meaning set forth in the
recitals at the beginning of this Agreement.

              (bb) "REDEMPTION DATE" shall have the meaning set forth in Section
23(a) hereof.

              (cc) "REDEMPTION PRICE" shall have the meaning set forth in
Section 23(a) hereof.

              (dd) "RIGHTS AGENT" shall mean (i) Computershare Trust Company,
Inc., (ii) its successor or replacement as provided in Sections 19 and 21 hereof
or (iii) any additional Person appointed pursuant to Section 2 hereof.

              (ee) "RIGHTS CERTIFICATE" shall mean a certificate substantially
in the form attached hereto as Exhibit B.

              (ff) "RIGHTS DIVIDEND DECLARATION DATE" shall have the meaning set
forth in the recitals at the beginning of this Agreement.

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

              (hh) "SECTION 13 EVENT" shall mean any event described in clause
(i), (ii) or (iii) of Section 13(a) hereof.

              (ii) "SECURITIES ACT" shall mean the Securities Act of 1933, as
amended.

              (jj) "SHARES ACQUISITION DATE" shall mean the first date of public
announcement (which, for purposes of this definition, shall include, without
limitation, a report filed pursuant to Section 13(d) under the Exchange Act) by
the Company or an Acquiring Person that an Acquiring Person has become such;
provided that, if such Person is determined not to have become an Acquiring
Person pursuant to Section 1(a) hereof, then no Shares Acquisition Date shall be
deemed to have occurred.

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


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<PAGE>   10

              (ll) "SUBSIDIARY" of any Person shall mean any corporation or
other entity of which an amount of voting securities sufficient to elect a
majority of the directors or Persons having similar authority of such
corporation or other entity is beneficially owned, directly or indirectly, by
such Person, or any corporation or other entity otherwise controlled by such
Person.

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

              (nn) "SUMMARY OF RIGHTS" shall mean a summary of this Agreement
substantially in the form attached hereto as Exhibit C.

              (oo) "TOTAL EXERCISE PRICE" shall have the meaning set forth in
Section 4(a) hereof.

              (pp) "TRADING DAY" shall mean a day on which the principal
national securities exchange on which a referenced security is listed or
admitted to trading is open for the transaction of business or, if a referenced
security is not listed or admitted to trading on any national securities
exchange, a Business Day.

              (qq) A "TRIGGERING EVENT" shall be deemed to have occurred upon
any Person becoming an Acquiring 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, upon ten (10) days' prior written notice to the Rights Agent. The
Rights Agent shall have no duty to supervise, and shall in no event be liable
for, the acts or omissions of any co-Rights Agent.

       Section 3. Issuance of Rights Certificates.

              (a) Until the Distribution Date, (i) the Rights will be evidenced
(subject to the provisions of Sections 3(b) and 3(c) hereof) by the certificates
for Common Shares registered in the names of the holders thereof (which
certificates shall also be deemed to be Rights Certificates) and not by separate
Rights Certificates and (ii) the right to receive Rights Certificates will be
transferable only in connection with the transfer of Common Shares. Until the
earlier of the Distribution Date or the Expiration Date, the surrender for
transfer or exchange of certificates for Common Shares shall also constitute the
surrender for transfer or exchange of the Rights associated with the Common
Shares represented thereby. 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, 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 or those of Exchangeco, a Rights
Certificate


                                      -7-
<PAGE>   11

evidencing one Right for each Common Share so held, subject to adjustment as
provided herein. In the event that an adjustment in the number of Rights per
Common Share has been made pursuant to Section 11 hereof, then at the time of
distribution of the Rights Certificates, the Company shall make the necessary
and appropriate rounding adjustments (in accordance with Section 14(a) hereof)
so that Rights Certificates representing only whole numbers of Rights are
distributed and cash is paid in lieu of any fractional Rights. As of the
Distribution Date, the Rights will be evidenced solely by such Rights
Certificates and may be transferred by the transfer of the Rights Certificates
as permitted hereby, separately and apart from any transfer of Common Shares,
and the holders of such Rights Certificates as listed in the records of the
Company or any transfer agent or registrar for the Rights shall be the record
holders thereof.

              (b) On the Record Date or as soon as practicable thereafter, the
Company will send a copy of 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's transfer agent and registrar or that of Exchangeco. 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 the Summary of
Rights.

              (c) Unless the Board of Directors by resolution adopted at or
before the time of the issuance of any Common Shares after the Record Date but
prior to the earlier of the Distribution Date or the Expiration Date (or, in
certain circumstances provided in Section 22 hereof, after the Distribution
Date) specifies to the contrary, Rights shall be issued in respect of all Common
Shares that are so issued, and Certificates representing such Common Shares
shall also be deemed to be certificates for Rights, and shall bear a legend
substantially as set forth below:

       THIS CERTIFICATE ALSO EVIDENCES AND ENTITLES THE HOLDER HEREOF TO CERTAIN
       RIGHTS AS SET FORTH IN A RIGHTS AGREEMENT BETWEEN CRITICAL PATH, INC. AND
       COMPUTERSHARE TRUST COMPANY, INC., AS THE RIGHTS AGENT, DATED AS OF MARCH
       19, 2001, (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 CRITICAL PATH, INC. UNDER CERTAIN
       CIRCUMSTANCES, AS SET FORTH IN THE RIGHTS AGREEMENT, SUCH RIGHTS WILL BE
       EVIDENCED BY SEPARATE CERTIFICATES AND WILL NO LONGER BE EVIDENCED BY
       THIS CERTIFICATE. CRITICAL PATH, 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 SET FORTH IN
       THE RIGHTS AGREEMENT, RIGHTS ISSUED TO, OR HELD BY, ANY PERSON WHO IS,
       WAS OR BECOMES AN ACQUIRING PERSON OR ANY AFFILIATE OR ASSOCIATE THEREOF
       (AS SUCH TERMS ARE DEFINED IN THE RIGHTS AGREEMENT), WHETHER CURRENTLY
       HELD BY OR ON BEHALF OF SUCH PERSON OR BY ANY SUBSEQUENT HOLDER, MAY
       BECOME NULL AND VOID.


                                      -8-
<PAGE>   12

With respect to such certificates containing the foregoing legend, until the
earlier of the Distribution Date or the Expiration Date, the Rights associated
with the Common Shares represented by such certificates shall be evidenced by
such certificates alone, and the surrender for transfer or exchange of any such
certificate shall also constitute the transfer or exchange of the Rights
associated with the Common Shares represented thereby.

              (d) In the event that the Company or any of its Affiliates
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
canceled and retired so that neither the Company nor any of its Affiliates shall
be entitled to exercise any Rights associated with the Common Shares which are
no longer outstanding or which are held by an Affiliate of the Company.

       Section 4. Form of Rights Certificates.

              (a) The Rights Certificates (and the forms of election to purchase
Common Shares of the Company and of assignment to be printed on the reverse
thereof) shall be substantially in the form of Exhibit B hereto and may have
such marks of identification or designation and such legends, summaries or
endorsements printed thereon as the Company may deem appropriate and as are not
inconsistent with the provisions of this Agreement, or as may be required to
comply with any applicable law or with any rule or regulation made pursuant
thereto or with any rule or regulation of any stock exchange or a national
market system, on which the Rights may from time to time be listed or included,
or to conform to usage. Subject to the provisions of Section 11 and Section 22
hereof, the Rights Certificates, whenever distributed, shall be dated as of the
Record Date (or in the case of Rights issued with respect to Common Shares
issued after the Record Date, as of the date of issuance of such Common Shares)
and on their face shall entitle the holders thereof to purchase such number of
one-thousandths of a Preferred Share as shall be set forth therein at the price
set forth therein (such exercise price per one one-thousandth of a Preferred
Share being hereinafter referred to as the "EXERCISE PRICE" and the aggregate
Exercise Price of all Preferred Shares issuable upon exercise of one Right being
hereinafter referred to as the "TOTAL EXERCISE PRICE"), but the number and type
of securities purchasable upon the exercise of each Right and the Exercise Price
shall be subject to adjustment as provided herein.

              (b) Any Rights Certificate issued pursuant to Section 3(a) or
Section 22 hereof that represents Rights beneficially owned by: (i) an Acquiring
Person or any Associate or Affiliate of an Acquiring Person, (ii) a Post-Event
Transferee, (iii) a Pre-Event Transferee or (iv) any subsequent transferee
receiving transferred Rights from a Post-Event Transferee or a Pre-Event
Transferee, either directly or through one or more intermediate transferees, and
any Rights Certificate issued pursuant to Section 6 or Section 11 hereof upon
transfer, exchange, replacement or adjustment of any other Rights Certificate
referred to in this sentence, shall contain (to the extent feasible) the
following legend:

       THE RIGHTS REPRESENTED BY THIS RIGHTS CERTIFICATE ARE OR WERE
       BENEFICIALLY OWNED BY A PERSON WHO WAS OR BECAME AN ACQUIRING PERSON OR
       AN AFFILIATE OR ASSOCIATE OF AN ACQUIRING PERSON (AS SUCH TERMS ARE
       DEFINED IN THE RIGHTS


                                      -9-
<PAGE>   13

       AGREEMENT). ACCORDINGLY, THIS RIGHTS CERTIFICATE AND THE RIGHTS
       REPRESENTED HEREBY MAY BECOME NULL AND VOID IN THE CIRCUMSTANCES
       SPECIFIED IN SECTION 7(e) OF THE RIGHTS AGREEMENT.

       Section 5. Countersignature and Registration.

              (a) The Rights Certificates shall be executed on behalf of the
Company by its Chairman of the Board, its Chief Executive Officer, its Chief
Financial Officer, its President or any Vice President, either manually or by
facsimile signature, and by the Secretary or an Assistant Secretary of the
Company, either manually or by facsimile signature, and shall have affixed
thereto the Company's seal (if any) or a facsimile thereof. The Rights
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 Rights Certificates shall cease to be
such officer of the Company before countersignature by the Rights Agent and
issuance and delivery by the Company, such Rights 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 Rights
Certificates on behalf of the Company had not ceased to be such officer of the
Company; and any Rights Certificate may be signed on behalf of the Company by
any person who, at the actual date of the execution of such Rights Certificate,
shall be a proper officer of the Company to sign such Rights Certificate,
although at the date of the execution of this Rights Agreement any such person
was not such an officer.

              (b) Following the Distribution Date, the Rights Agent will keep or
cause to be kept, at its office designated for such purposes, books for
registration and transfer of the Rights Certificates issued hereunder. Such
books shall show the names and addresses of the respective holders of the Rights
Certificates, the number of Rights evidenced on its face by each of the Rights
Certificates and the date of each of the Rights Certificates.

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

              (a) Subject to the provisions of Sections 7(e), 14 and 24 hereof,
at any time after the Close of Business on the Distribution Date, and at or
prior to the Close of Business on the Expiration Date, any Rights Certificate or
Rights Certificates may be transferred, split up, combined or exchanged for
another Rights Certificate or Rights Certificates, entitling the registered
holder to purchase a like number of one-thousandths of a Preferred Share (or,
following a Triggering Event, other securities, cash or other assets, as the
case may be) as the Rights Certificate or Rights Certificates surrendered then
entitled such holder to purchase. Any registered holder desiring to transfer,
split up, combine or exchange any Rights Certificate or Rights Certificates
shall make such request in writing delivered to the Rights Agent, and shall
surrender the Rights Certificate or Rights Certificates to be transferred, split
up, combined or exchanged at the office of the Rights Agent designated for such
purpose. Neither the Rights Agent nor the Company shall be obligated to take any
action whatsoever with respect to the transfer of any such surrendered Rights
Certificate until the registered holder shall have completed and signed the
certificate contained in the form of


                                      -10-
<PAGE>   14

assignment on the reverse side of such Rights Certificate and shall have
provided such additional evidence of the identity of the Beneficial Owner (or
former Beneficial Owner) or Affiliates or Associates thereof as the Company
shall reasonably request. Thereupon the Rights Agent shall, subject to Sections
7(e), 14 and 24 hereof, countersign and deliver to the person entitled thereto a
Rights Certificate or Rights 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 Rights Certificates.

              (b) Upon receipt by the Company and the Rights Agent of evidence
reasonably satisfactory to them of the loss, theft, destruction or mutilation of
a Rights 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 Rights Certificate if mutilated, the Company will make and deliver a new
Rights Certificate of like tenor to the Rights Agent for delivery to the
registered holder in lieu of the Rights Certificate so lost, stolen, destroyed
or mutilated.

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

              (a) Subject to Sections 7(e), 23(b) and 24(b) hereof, the
registered holder of any Rights Certificate may exercise the Rights evidenced
thereby (except as otherwise provided herein) in whole or in part at any time
after the Distribution Date and prior to the Close of Business on the Expiration
Date by surrender of the Rights Certificate, with the form of election to
purchase on the reverse side thereof duly executed, to the Rights Agent at the
office of the Rights Agent designated for such purpose, together with payment of
the Exercise Price for each one-thousandth of a Preferred Share (or, following a
Triggering Event, other securities, cash or other assets as the case may be) as
to which the Rights are exercised.

              (b) The Exercise Price for each one-thousandth of a Preferred
Share issuable pursuant to the exercise of a Right shall initially be
Twenty-five Dollars ($25.00), shall be subject to adjustment from time to time
as provided in Sections 11 and 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 Rights Certificate representing exercisable
Rights, with the form of election to purchase duly executed, accompanied by
payment of the Exercise Price for the number of one-thousandths of a Preferred
Share (or, following a Triggering Event, other securities, cash or other assets
as the case may be) to be purchased and an amount equal to any applicable
transfer tax required to be paid by the holder of such Rights Certificate in
accordance with Section 9(e) hereof, the Rights Agent shall, subject to Section
20(k) hereof, thereupon promptly (i) (A) requisition from any transfer agent of
the Preferred Shares (or make available, if the Rights Agent is the transfer
agent for the Preferred Shares) a certificate or certificates for the number of
one-thousandths of a Preferred Share (or, following a Triggering Event, other
securities, cash or other assets as the case may be) to be purchased and the
Company hereby irrevocably authorizes its transfer agent to comply with all such
requests or (B) if the Company shall have elected to deposit the total number of
one-thousandths of a Preferred Share (or, following a Triggering Event, other


                                      -11-
<PAGE>   15

securities, cash or other assets as the case may be) issuable upon exercise of
the Rights hereunder with a depositary agent, requisition from the depositary
agent depositary receipts representing such number of one-thousandths of a
Preferred Share (or, following a Triggering Event, other securities, cash or
other assets as the case may be) as are to be purchased (in which case
certificates for the Preferred Shares (or, following a Triggering Event, other
securities, cash or other assets as the case may be) 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
Rights Certificate, registered in such name or names as may be designated by
such holder and (iv) when appropriate, after receipt thereof, deliver such cash
to or upon the order of the registered holder of such Rights Certificate. The
payment of the Exercise Price (as such amount may be reduced (including to zero)
pursuant to Section 11(a)(iii) hereof) and an amount equal to any applicable
transfer tax required to be paid by the holder of such Rights Certificate in
accordance with Section 9(e) hereof, may be made in cash or by certified bank
check, cashier's check or bank draft payable to the order of the Company. In the
event that the Company is obligated to issue securities of the Company other
than Preferred Shares, pay cash and/or distribute other property pursuant to
Section 11(a) hereof, the Company will make all arrangements necessary so that
such other securities, cash and/or other property are available for distribution
by the Rights Agent, if and when appropriate.

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

              (e) Notwithstanding anything in this Agreement to the contrary,
from and after the first occurrence of a Triggering Event, any Rights
beneficially owned by (i) an Acquiring Person or an Associate or Affiliate of an
Acquiring Person, (ii) a transferee of an Acquiring Person (or of any such
Associate or Affiliate) who becomes a transferee after the Acquiring Person
becomes such (a "POST-EVENT TRANSFEREE"), (iii) a transferee of an Acquiring
Person (or of any such Associate or Affiliate) who becomes a transferee prior to
or concurrently with the Acquiring Person becoming such and receives such Rights
pursuant to either (A) a transfer (whether or not for consideration) from the
Acquiring Person to holders of equity interests in such Acquiring Person or to
any Person with whom the Acquiring Person has any continuing agreement,
arrangement or understanding regarding the transferred Rights or (B) a transfer
which the Company's Board of Directors has determined is part of a plan,
arrangement or understanding which has as a primary purpose or effect the
avoidance of this Section 7(e) (a "PRE-EVENT TRANSFEREE") or (iv) any subsequent
transferee receiving transferred Rights from a Post-Event Transferee or a
Pre-Event Transferee, either directly or through one or more intermediate
transferees, shall become null and void without any further action and no holder
of such Rights shall have any rights whatsoever with respect to such Rights,
whether under any provision of this Agreement or otherwise. The Company shall
use all reasonable efforts to ensure that the provisions of this Section 7(e)
and Section 4(b) hereof are complied with, but shall have no liability to any
holder of Rights Certificates or to any other Person as a result of its


                                      -12-
<PAGE>   16

failure to make any determinations with respect to an Acquiring Person or any of
such Acquiring Person's Affiliates, Associates or transferees hereunder.

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

       Section 8. Cancellation and Destruction of Rights Certificates. All
Rights 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 canceled form,
or, if surrendered to the Rights Agent, shall be canceled by it, and no Rights
Certificates shall be issued in lieu thereof except as expressly permitted by
any of the provisions of this Agreement. The Company shall deliver to the Rights
Agent for cancellation and retirement, and the Rights Agent shall so cancel and
retire, any Rights Certificate purchased or acquired by the Company otherwise
than upon the exercise thereof. The Rights Agent shall deliver all canceled
Rights Certificates to the Company, or shall, at the written request of the
Company, destroy such canceled Rights Certificates, and in such case shall
deliver a certificate evidencing the destruction thereof to the Company.

       Section 9. Reservation and Availability of Preferred Shares.

              (a) The Company covenants and agrees that it will use its best
efforts to cause to be reserved and kept available out of its authorized and
unissued Preferred Shares not reserved for another purpose (and, following the
occurrence of a Triggering Event, out of its authorized and unissued Common
Shares of the Company and/or other securities), the number of Preferred Shares
(and, following the occurrence of the Triggering Event, Common Shares of the
Company and/or other securities) that will be sufficient to permit the exercise
in full of all outstanding Rights.

              (b) If the Company shall hereafter list any of its Preferred
Shares on a national securities exchange, then so long as the Preferred Shares
(and, following the occurrence of a Triggering Event, Common Shares of the
Company and/or other securities) issuable and deliverable upon exercise of the
Rights may be listed on such exchange, the Company shall use its best efforts to
cause, from and after such time as the Rights become exercisable (but only to
the extent that it is reasonably likely that the Rights will be exercised), all
shares reserved for such issuance to be listed on such exchange upon official
notice of issuance upon such exercise.

              (c) The Company shall use its best efforts to (i) file, as soon as
practicable following the earliest date after the first occurrence of a
Triggering Event in which the consideration to be delivered by the Company upon
exercise of the Rights is described in Section 11(a)(ii) or Section 11(a)(iii)
hereof, or as soon as is required by law following the Distribution Date, as the
case


                                      -13-
<PAGE>   17

may be, a registration statement under the Securities Act with respect to the
securities purchasable upon exercise of the Rights on an appropriate form, (ii)
cause such registration statement to become effective as soon as practicable
after such filing and (iii) cause such registration statement to remain
effective (with a prospectus at all times meeting the requirements of the
Securities Act) until the earlier of (A) the date as of which the Rights are no
longer exercisable for such securities and (B) the date of expiration of the
Rights. The Company may temporarily suspend, for a period not to exceed ninety
(90) days after the date set forth in clause (i) of the first sentence of this
Section 9(c), the exercisability of the Rights in order to prepare and file such
registration statement and permit it to become effective. Upon any such
suspension, the Company shall issue a public announcement stating, and notify
the Rights Agent, that the exercisability of the Rights has been temporarily
suspended, as well as a public announcement and notification to the Rights Agent
at such time as the suspension is no longer in effect. The Company will also
take such action as may be appropriate under, or to ensure compliance with, the
securities or "blue sky" laws of the various states and the various provinces of
Canada in connection with the exercisability of the Rights. Notwithstanding any
provision of this Agreement to the contrary, the Rights shall not be exercisable
in any jurisdiction, unless the requisite qualification in such jurisdiction
shall have been obtained, or an exemption therefrom shall be available, and
until a registration statement has been declared and remains effective.

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

              (e) The Company further covenants and agrees that it will pay when
due and payable any and all federal and state transfer taxes and charges which
may be payable in respect of the original issuance or delivery of the Rights
Certificates or of any Preferred Shares (or other securities of the Company)
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
Rights Certificates to a person other than, or the issuance or delivery of
certificates or depositary receipts for the Preferred Shares (or other
securities of the Company) in a name other than that of, the registered holder
of the Rights Certificate evidencing Rights surrendered for exercise or to issue
or to deliver any certificates or depositary receipts for Preferred Shares (or
other securities of the Company) upon the exercise of any Rights until any such
tax shall have been paid (any such tax being payable by the holder of such
Rights Certificate at the time of surrender) or until it has been established to
the Company's satisfaction that no such tax is due.

       Section 10. Record Date. Each Person in whose name any certificate for a
number of one-thousandths of a Preferred Share (or other securities of the
Company) is issued upon the exercise of Rights shall for all purposes be deemed
to have become the holder of record of Preferred Shares (or other securities of
the Company) represented thereby on, and such certificate shall be dated, the
date upon which the Rights Certificate evidencing such Rights was duly
surrendered and payment of the Total Exercise Price with respect to which the
Rights have been exercised (and any applicable transfer taxes) was made;
provided, however, that if the date of such surrender and payment is a date


                                      -14-
<PAGE>   18

upon which the 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 transfer books of
the Company are open. Prior to the exercise of the Rights evidenced thereby, the
holder of a Rights Certificate shall not be entitled to any rights of a holder
of Preferred Shares (or other securities of the Company) for which the Rights
shall be exercisable, including, without limitation, the right to vote, to
receive dividends or other distributions or to exercise any preemptive rights,
and shall not be entitled to receive any notice of any proceedings of the
Company, except as provided herein.

       Section 11. Adjustment of Exercise Price, Number of Shares or Number of
Rights. The Exercise Price, the number and kind of shares or other property
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) Anything in this Agreement to the contrary
notwithstanding, in the event that 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 (by reverse stock split or otherwise) into 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), then, in each such event,
except as otherwise provided in this Section 11 and Section 7(e) hereof: (1) the
Exercise Price in effect at the time of the record date for such dividend or of
the effective date of such subdivision, combination or reclassification shall be
adjusted so that the Exercise Price thereafter shall equal the result obtained
by dividing the Exercise Price in effect immediately prior to such time by a
fraction (the "ADJUSTMENT FRACTION"), the numerator of which shall be the total
number of Preferred Shares (or shares of capital stock issued in such
reclassification of the Preferred Shares) outstanding immediately following such
time and the denominator of which shall be the total number of Preferred Shares
outstanding immediately prior to such time; 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 such Right; and (2) the number of one-thousandths of a
Preferred Share (or share of such other capital stock) issuable upon the
exercise of each Right shall equal the number of one-thousandths of a Preferred
Share (or share of such other capital stock) as was issuable upon exercise of a
Right immediately prior to the occurrence of the event described in clauses
(A)-(D) of this Section 11(a)(i), multiplied by the Adjustment Fraction;
provided, however, that, no such adjustment shall be made pursuant to this
Section 11(a)(i) to the extent that there shall have simultaneously occurred an
event described in clause (A), (B), (C) or (D) of Section 11(n) with a
proportionate adjustment being made thereunder. Each Common Share that shall
become outstanding after an adjustment has been made pursuant to this Section
11(a)(i) shall have associated with it the number of Rights, exercisable at the
Exercise Price and for the number of one-thousandths of a Preferred Share (or
shares of such other capital stock) as one Common Share has associated with it
immediately following the adjustment made pursuant to this Section 11(a)(i).


                                      -15-
<PAGE>   19

                     (i) Subject to Section 24 of this Agreement, in the event
that a Triggering Event shall have occurred, then promptly following such
Triggering Event each holder of a Right, except as provided in Section 7(e)
hereof, shall thereafter have the right to receive for each Right, upon exercise
thereof in accordance with the terms of this Agreement and payment of the
Exercise Price in effect immediately prior to the occurrence of the Triggering
Event, in lieu of a number of one-thousandths of a Preferred Share, such number
of Common Shares of the Company as shall equal the quotient obtained by dividing
(A) the product obtained by multiplying (1) the Exercise Price in effect
immediately prior to the occurrence of the Triggering Event by (2) the number of
one-thousandths of a Preferred Share for which a Right was exercisable (or would
have been exercisable if the Distribution Date had occurred) immediately prior
to the first occurrence of a Triggering Event, by (B) 50% of the Current Per
Share Market Price for Common Shares of the Company on the date of occurrence of
the Triggering Event; provided, however, that the Exercise Price and the number
of Common Shares of the Company so receivable upon exercise of a Right shall be
subject to further adjustment as appropriate in accordance with Section 11(e)
hereof to reflect any events occurring in respect of the Common Shares of the
Company after the occurrence of the Triggering Event.

                     (ii) In lieu of issuing Common Shares of the Company in
accordance with Section 11(a)(ii) hereof, the Company may, if the Company's
Board of Directors determines that such action is necessary or appropriate and
not contrary to the interest of holders of Rights and, in the event that the
number of Common Shares of the Company which are authorized by the Company's
Certificate of Incorporation but not outstanding or reserved for issuance for
purposes other than upon exercise of the Rights are not sufficient to permit the
exercise in full of the Rights, or if any necessary regulatory approval for such
issuance has not been obtained by the Company, the Company shall: (A) determine
the excess of (1) the value of the Common Shares of the Company issuable upon
the exercise of a Right (the "CURRENT VALUE") over (2) the Exercise Price (such
excess, the "SPREAD") and (B) with respect to each Right, make adequate
provision to substitute for such Common Shares of the Company, upon exercise of
the Rights, (1) cash, (2) a reduction in the Exercise Price, (3) other equity
securities of the Company (including, without limitation, shares or units of
shares of any series of preferred stock which the Company's Board of Directors
has deemed to have the same value as Common Shares of the Company (such shares
or units of shares of preferred stock are herein called "COMMON STOCK
Equivalents")), except to the extent that the Company has not obtained any
necessary stockholder or regulatory approval for such issuance, (4) debt
securities of the Company, except to the extent that the Company has not
obtained any necessary stockholder or regulatory approval for such issuance, (5)
other assets or (6) any combination of the foregoing, having an aggregate value
equal to the Current Value, where such aggregate value has been determined by
the Company's Board of Directors based upon the advice of a nationally
recognized investment banking firm selected by the Company's Board of Directors;
provided, however, that if the Company shall not have made adequate provision to
deliver value pursuant to clause (B) above within thirty (30) days following the
later of (x) the first occurrence of a Triggering Event and (y) the date on
which the Company's right of redemption pursuant to Section 23(a) expires (the
later of (x) and (y) being referred to herein as the "SECTION 11(a)(ii) TRIGGER
DATE"), then the Company shall be obligated to deliver, upon the surrender for
exercise of a Right and without requiring payment of the Exercise Price, Common
Shares of the Company (to the extent available), except to the extent that the
Company has not obtained any necessary stockholder


                                      -16-
<PAGE>   20

or regulatory approval for such issuance, and then, if necessary, cash, which
shares and/or cash have an aggregate value equal to the Spread. If the Company's
Board of Directors shall determine in good faith that it is likely that
sufficient additional Common Shares of the Company could be authorized for
issuance upon exercise in full of the Rights or that any necessary regulatory
approval for such issuance will be obtained, the thirty (30) day period set
forth above may be extended to the extent necessary, but not more than ninety
(90) days after the Section 11(a)(ii) Trigger Date, in order that the Company
may seek stockholder approval for the authorization of such additional shares or
take action to obtain such regulatory approval (such period, as it may be
extended, the "SUBSTITUTION PERIOD"). To the extent that the Company determines
that some action need be taken pursuant to the first and/or second sentences of
this Section 11(a)(iii), the Company (x) shall provide, subject to Section 7(e)
hereof, that such action shall apply uniformly to all outstanding Rights and (y)
may suspend the exercisability of the Rights until the expiration of the
Substitution Period in order to seek any authorization of additional shares, to
take any action to obtain any required regulatory approval and/or to decide the
appropriate form of distribution to be made pursuant to such first sentence and
to determine the value thereof. In the event of any such suspension, the Company
shall issue a public announcement stating that the exercisability of the Rights
has been temporarily suspended, as well as a public announcement at such time as
the suspension is no longer in effect. For purposes of this Section 11(a)(iii),
the value of the Common Shares of the Company shall be the Current Per Share
Market Price of the Common Shares of the Company on the Section 11(a)(ii)
Trigger Date and the value of any Common Stock Equivalent shall be deemed to
have the same value as the Common Shares of the Company on such date.

              (b) In case the Company shall, at any time after the date of this
Agreement, fix a record date for the issuance of rights, options or warrants to
all holders of Preferred Shares entitling such holders (for a period expiring
within forty-five (45) calendar days after such record date) to subscribe for or
purchase Preferred Shares or Equivalent Shares or securities convertible into
Preferred Shares or Equivalent Shares at a price per share (or having a
conversion price per share, if a security convertible into Preferred Shares or
Equivalent Shares) less than the then Current Per Share Market Price of the
Preferred Shares or Equivalent Shares on such record date, then, in each such
case, the Exercise Price to be in effect after such record date shall be
determined by multiplying the Exercise Price in effect immediately prior to such
record date by a fraction, the numerator of which shall be the number of
Preferred Shares and Equivalent Shares (if any) outstanding on such record date,
plus the number of Preferred Shares or Equivalent Shares, as the case may be,
which the aggregate offering price of the total number of Preferred Shares or
Equivalent Shares, as the case may be, to be offered or issued (and/or the
aggregate initial conversion price of the convertible securities to be offered
or issued) would purchase at such current market price, and the denominator of
which shall be the number of Preferred Shares and Equivalent Shares (if any)
outstanding on such record date, plus the number of additional Preferred Shares
or Equivalent Shares, as the case may be, 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 Company's
Board of Directors, whose determination shall be described in a statement filed
with the Rights Agent and shall be binding on the Rights


                                      -17-
<PAGE>   21

Agent and the holders of the Rights. Preferred Shares and Equivalent 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 Exercise Price shall be
adjusted to be the Exercise Price which would then be in effect if such record
date had not been fixed.

              (c) In case the Company shall, at any time after the date of this
Agreement, fix a record date for the making of a distribution to all holders of
the Preferred Shares or of any class or series of Equivalent 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, if any, or
a dividend payable in Preferred Shares) or subscription rights, options or
warrants (excluding those referred to in Section 11(b)), then, in each such
case, the Exercise Price to be in effect after such record date shall be
determined by multiplying the Exercise Price in effect immediately prior to such
record date by a fraction, the numerator of which shall be the Current Per Share
Market Price of a Preferred Share or an Equivalent Share on such record date,
less the fair market value per Preferred Share or Equivalent 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) of
the portion of the cash, assets or evidences of indebtedness so to be
distributed or of such subscription rights or warrants applicable to a Preferred
Share or Equivalent Share, as the case may be, and the denominator of which
shall be such Current Per Share Market Price of a Preferred Share or Equivalent
Share on such record date; 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. Such adjustments shall be made successively whenever such
a record date is fixed, and in the event that such distribution is not so made,
the Exercise Price shall be adjusted to be the Exercise Price which would have
been in effect if such record date had not been fixed.

              (d) Anything herein to the contrary notwithstanding, no adjustment
in the Exercise Price shall be required unless such adjustment would require an
increase or decrease of at least one percent (1.0%) of the Exercise Price;
provided, however, that any adjustments which by reason of this Section 11(d)
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 ten-thousandth of a Common Share of the
Company or other share or one hundred-thousandth of a Preferred Share, as the
case may be. Notwithstanding the first sentence of this Section 11(d), any
adjustment required by this Section 11 shall be made no later than the earlier
of (i) three (3) years from the date of the transaction which requires such
adjustment or (ii) the Expiration Date.

              (e) If as a result of an adjustment made pursuant to Section 11(a)
or Section 13(a) hereof, the holder of any Right thereafter exercised shall
become entitled to receive any shares of capital stock other than Preferred
Shares, thereafter the number of such other shares so receivable upon exercise
of any Right and, if required, the Exercise Price thereof, 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
Sections 11(a), 11(b), 11(c), 11(d), 11(g), 11(h), 11(i),


                                      -18-
<PAGE>   22

11(j), 11(k) and 11(l), and the provisions of Sections 7, 9, 10, 13 and 14 with
respect to the Preferred Shares shall apply on like terms to any such other
shares.

              (f) All Rights originally issued by the Company subsequent to any
adjustment made to the Exercise Price hereunder shall evidence the right to
purchase, at the adjusted Exercise Price, the number of one-thousandths of a
Preferred Share purchasable from time to time hereunder upon exercise of the
Rights, all subject to further adjustment as provided herein.

              (g) Unless the Company shall have exercised its election as
provided in Section 11(h), upon each adjustment of the Exercise Price as a
result of the calculations made in Section 11(b) and (c), each Right outstanding
immediately prior to the making of such adjustment shall thereafter evidence the
right to purchase, at the adjusted Exercise Price, that number of Preferred
Shares (calculated to the nearest one hundred-thousandth of a share) obtained by
(i) multiplying (x) the number of Preferred Shares covered by a Right
immediately prior to this adjustment, by (y) the Exercise Price in effect
immediately prior to such adjustment of the Exercise Price, and (ii) dividing
the product so obtained by the Exercise Price in effect immediately after such
adjustment of the Exercise Price.

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


                                      -19-
<PAGE>   23

               (i) Irrespective of any adjustment or change in the Exercise
Price or the number of Preferred Shares issuable upon the exercise of the
Rights, the Rights Certificates theretofore and thereafter issued may continue
to express the Exercise Price per one one-thousandth of a Preferred Share and
the number of one-thousandths of a Preferred Share which were expressed in the
initial Rights Certificates issued hereunder.

               (j) Before taking any action that would cause an adjustment
reducing the Exercise Price below the par or stated value, if any, of the number
of one-thousandths of a Preferred Share 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 as
fully paid and nonassessable shares such number of one-thousandths of a
Preferred Share at such adjusted Exercise Price.

               (k) In any case in which this Section 11 shall require that an
adjustment in the Exercise Price be made effective as of a record date for a
specified event, the Company may elect to defer until the occurrence of such
event the issuing to the holder of any Right exercised after such record date of
the number of one-thousandths of a Preferred Share and other capital stock or
securities of the Company, if any, issuable upon such exercise over and above
the number of one-thousandths of a Preferred Share and other capital stock or
securities of the Company, if any, issuable upon such exercise on the basis of
the Exercise Price in effect prior to such adjustment; provided, however, that
the Company shall deliver to such holder a due bill or other appropriate
instrument evidencing such holder's right to receive such additional shares
(fractional or otherwise) upon the occurrence of the event requiring such
adjustment.

               (l) Anything in this Section 11 to the contrary notwithstanding,
prior to the Distribution Date, the Company shall be entitled to make such
reductions in the Exercise Price, in addition to those adjustments expressly
required by this Section 11, as and to the extent that it in its sole discretion
shall determine to be advisable in order that any (i) consolidation or
subdivision of the Preferred Shares or Common Shares of the Company, (ii)
issuance wholly for cash of any Preferred Shares or Common Shares of the Company
at less than the current market price, (iii) issuance wholly for cash of
Preferred Shares or Common Shares of the Company or securities which by their
terms are convertible into or exchangeable for Preferred Shares or Common Shares
of the Company, (iv) stock dividends or (v) issuance of rights, options or
warrants referred to in this Section 11, hereafter made by the Company to
holders of its Preferred Shares or Common Shares of the Company shall not be
taxable to such stockholders.

               (m) The Company covenants and agrees that, after the Distribution
Date, it will not, except as permitted by Sections 23, 24 or 27 hereof, take (or
permit to be taken) any action if at the time such action is taken it is
reasonably foreseeable that such action will diminish substantially or otherwise
eliminate the benefits intended to be afforded by the Rights.

               (n) In the event that the Company shall at any time after the
date of this Agreement (A) declare a dividend on the Common Shares of the
Company payable in Common Shares of the Company, (B) subdivide the outstanding
Common Shares of the Company, (C) combine the outstanding Common Shares of the
Company (by reverse stock split or otherwise)


                                      -20-
<PAGE>   24

into a smaller number of Common Shares of the Company, or (D) issue any shares
of its capital stock in a reclassification of the Common Shares of the Company
(including any such reclassification in connection with a consolidation or
merger in which the Company is the continuing or surviving corporation), then,
in each such event, except as otherwise provided in this Section 11(a) and
Section 7(e) hereof: (1) each Common Share (or shares of capital stock issued in
such reclassification of the Common Shares of the Company) outstanding
immediately following such time shall have associated with it the number of
Rights as were associated with one Common Share immediately prior to the
occurrence of the event described in clauses (A)-(D) above; (2) the Exercise
Price in effect at the time of the record date for such dividend or of the
effective date of such subdivision, combination or reclassification shall be
adjusted so that the Exercise Price thereafter shall equal the result obtained
by multiplying the Exercise Price in effect immediately prior to such time by a
fraction, the numerator of which shall be the total number of Common Shares
outstanding immediately prior to the event described in clauses (A)-(D) above,
and the denominator of which shall be the total number of Common Shares
outstanding immediately after such event; 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 such Right; and (3) the number of one-thousandths of a
Preferred Share (or shares of such other capital stock) issuable upon the
exercise of each Right outstanding after such event shall equal the number of
one-thousandths of a Preferred Share (or shares of such other capital stock) as
were issuable with respect to one Right immediately prior to such event. Each
Common Share that shall become outstanding after an adjustment has been made
pursuant to this Section 11(n) shall have associated with it the number of
Rights, exercisable at the Exercise Price and for the number of one-thousandths
of a Preferred Share (or shares of such other capital stock) as one Common Share
has associated with it immediately following the adjustment made pursuant to
this Section 11(n). If an event occurs which would require an adjustment under
both this Section 11(n) and Section 11(a)(ii) hereof, the adjustment provided
for in this Section 11(n) shall be in addition to, and shall be made prior to,
any adjustment required pursuant to Section 11(a)(ii) hereof.

        Section 12. Certificate of Adjusted Exercise Price or Number of Shares.
Whenever an adjustment is made as provided in Sections 11 and 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 Preferred Shares a copy of
such certificate and (c) mail a brief summary thereof to each holder of a Rights
Certificate in accordance with Section 26 hereof. Notwithstanding the foregoing
sentence, the failure of the Company to make such certification or give such
notice shall not affect the validity of such adjustment or the force or effect
of the requirement for such adjustment. The Rights Agent shall be fully
protected in relying on any such certificate and on any adjustment contained
therein and shall not be deemed to have knowledge of such adjustment unless and
until it shall have received such certificate.

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

               (a) In the event that, following a Triggering Event, directly or
indirectly:


                                      -21-
<PAGE>   25

                      (i) the Company shall consolidate with, or merge with and
into, any other Person (other than a wholly-owned Subsidiary of the Company in a
transaction the principal purpose of which is to change the state of
incorporation of the Company and which complies with Section 11(m) hereof);

                      (ii) 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 consolidation or merger and, in connection with
such merger, all or part of the Common Shares of the Company shall be changed
into or exchanged for stock or other securities of any other person (or the
Company); or

                      (iii) 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 or Persons (other than the Company or one or more of its wholly
owned Subsidiaries in one or more transactions, each of which individually (and
together) complies with Section 11(m) hereof),

                             then, concurrent with and in each such case,

                             (A) each holder of a Right (except as provided in
Section 7(e) hereof) shall thereafter have the right to receive, upon the
exercise thereof at a price equal to the Total Exercise Price applicable
immediately prior to the occurrence of the Section 13 Event in accordance with
the terms of this Agreement, such number of validly authorized and issued, fully
paid, nonassessable and freely tradeable Common Shares of the Principal Party
(as hereinafter defined), free of any liens, encumbrances, rights of first
refusal or other adverse claims, as shall be equal to the result obtained by
dividing such Total Exercise Price by an amount equal to fifty percent (50%) of
the Current Per Share Market Price of the Common Shares of such Principal Party
on the date of consummation of such Section 13 Event, provided, however, that
the Exercise Price and the number of Common Shares of such Principal Party so
receivable upon exercise of a Right shall be subject to further adjustment as
appropriate in accordance with Section 11(e) hereof;

                             (B) such Principal Party shall thereafter be liable
for, and shall assume, by virtue of such Section 13 Event, all the obligations
and duties of the Company pursuant to this Agreement;

                             (C) the term "Company" shall thereafter be deemed
to refer to such Principal Party, it being specifically intended that the
provisions of Section 11 hereof shall apply only to such Principal Party
following the first occurrence of a Section 13 Event;

                             (D) such Principal Party shall take such steps
(including, but not limited to, the reservation of a sufficient number of its
Common Shares) in connection with the consummation of any such transaction as
may be necessary to ensure that the provisions hereof shall thereafter be
applicable, as nearly as reasonably may be, in relation to its Common Shares
thereafter deliverable upon the exercise of the Rights; and


                                      -22-
<PAGE>   26

                             (E) upon the subsequent occurrence of any
consolidation, merger, sale or transfer of assets or other extraordinary
transaction in respect of such Principal Party, each holder of a Right shall
thereupon be entitled to receive, upon exercise of a Right and payment of the
Total Exercise Price as provided in this Section 13(a), such cash, shares,
rights, warrants and other property which such holder would have been entitled
to receive had such holder, at the time of such transaction, owned the Common
Shares of the Principal Party receivable upon the exercise of such Right
pursuant to this Section 13(a), and such Principal Party shall take such steps
(including, but not limited to, reservation of shares of stock) as may be
necessary to permit the subsequent exercise of the Rights in accordance with the
terms hereof for such cash, shares, rights, warrants and other property.

                             (F) For purposes hereof, the "earning power" of the
Company and its Subsidiaries shall be determined in good faith by the Company's
Board of Directors on the basis of the operating income of each business
operated by the Company and its Subsidiaries during the three fiscal years
preceding the date of such determination (or, in the case of any business not
operated by the Company or any Subsidiary during three full fiscal years
preceding such date, during the period such business was operated by the Company
or any Subsidiary).

               (b) For purposes of this Agreement, the term "PRINCIPAL PARTY"
shall mean:

                      (i) in the case of any transaction described in clause (i)
or (ii) of Section 13(a) hereof: (A) the Person that is the issuer of the
securities into which the Common Shares of the Company are converted in such
merger or consolidation, or, if there is more than one such issuer, the issuer
the Common Shares of which have the greatest aggregate market value of shares
outstanding, or (B) if no securities are so issued, (x) the Person that is the
other party to the merger, if such Person survives said merger, or, if there is
more than one such Person, the Person the Common Shares of which have the
greatest aggregate market value of shares outstanding or (y) if the Person that
is the other party to the merger does not survive the merger, the Person that
does survive the merger (including the Company if it survives) or (z) the Person
resulting from the consolidation; and

                      (ii) in the case of any transaction described in clause
(iii) of Section 13(a) hereof, the Person that is the party receiving the
greatest portion of the assets or earning power transferred pursuant to such
transaction or transactions, or, if more than one Person that is a party to such
transaction or transactions receives the same portion of the assets or earning
power so transferred and each such portion would, were it not for the other
equal portions, constitute the greatest portion of the assets or earning power
so transferred, or if the Person receiving the greatest portion of the assets or
earning power cannot be determined, whichever of such Persons is the issuer of
Common Shares having the greatest aggregate market value of shares outstanding;
provided, however, that in any such case described in the foregoing clause
(b)(i) or (b)(ii), if the Common Shares of such Person are not at such time or
have not been continuously over the preceding 12-month period registered under
Section 12 of the Exchange Act, then (1) if such Person is a direct or indirect
Subsidiary of another Person the Common Shares of which are and have been so
registered, the term "Principal Party" shall refer to such other Person, or (2)
if such Person is a Subsidiary, directly or indirectly, of more than one Person,
the Common Shares of which are and have been so


                                      -23-
<PAGE>   27

registered, the term "Principal Party" shall refer to whichever of such Persons
is the issuer of Common Shares having the greatest aggregate market value of
shares outstanding, or (3) if such Person is owned, directly or indirectly, by a
joint venture formed by two or more Persons that are not owned, directly or
indirectly by the same Person, the rules set forth in clauses (1) and (2) above
shall apply to each of the owners having an interest in the venture as if the
Person owned by the joint venture was a Subsidiary of both or all of such joint
venturers, and the Principal Party in each such case shall bear the obligations
set forth in this Section 13 in the same ratio as its interest in such Person
bears to the total of such interests.

               (c) The Company shall not consummate any Section 13 Event unless
the Principal Party shall have a sufficient number of authorized Common Shares
that have not been issued or reserved for issuance to permit the exercise in
full of the Rights in accordance with this Section 13 and unless prior thereto
the Company and such issuer shall have executed and delivered to the Rights
Agent a supplemental agreement confirming that such Principal Party shall, upon
consummation of such Section 13 Event, assume this Agreement in accordance with
Sections 13(a) and 13(b) hereof, that all rights of first refusal or preemptive
rights in respect of the issuance of Common Shares of such Principal Party upon
exercise of outstanding Rights have been waived, that there are no 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 and that such transaction shall not result in a default by such Principal
Party under this Agreement, and further providing that, as soon as practicable
after the date of such Section 13 Event, such Principal Party will:

                      (i) prepare and file a registration statement under the
Securities Act with respect to the Rights and the securities purchasable upon
exercise of the Rights on an appropriate form, use its best efforts to cause
such registration statement to become effective as soon as practicable after
such filing and use its best efforts to cause such registration statement to
remain effective (with a prospectus at all times meeting the requirements of the
Securities Act) until the Expiration Date, and similarly comply with applicable
state or Canadian provincial securities laws;

                      (ii) use its best efforts to list (or continue the listing
of) the Rights and the securities purchasable upon exercise of the Rights on a
national securities exchange or to meet the eligibility requirements for
quotation on Nasdaq and list (or continue the listing of) the Rights and the
securities purchasable upon exercise of the Rights on Nasdaq; and

                      (iii) deliver to holders of the Rights historical
financial statements for such Principal Party which comply in all respects with
the requirements for registration on Form 10 (or any successor form) under the
Exchange Act.

        In the event that at any time after the occurrence of a Triggering Event
some or all of the Rights shall not have been exercised at the time of a
transaction described in this Section 13, the Rights which have not theretofore
been exercised shall thereafter be exercisable in the manner described in
Section 13(a) (without taking into account any prior adjustment required by
Section 11(a)(ii)).


                                      -24-
<PAGE>   28

               (d) In case the "Principal Party" for purposes of Section 13(b)
hereof has provision in any of its authorized securities or in its certificate
of incorporation or by-laws or other instrument governing its corporate affairs,
which provision would have the effect of (i) causing such Principal Party to
issue (other than to holders of Rights pursuant to Section 13 hereof), in
connection with, or as a consequence of, the consummation of a Section 13 Event,
Common Shares or Equivalent Shares of such Principal Party at less than the then
Current Per Share Market Price thereof or securities exercisable for, or
convertible into, Common Shares or Equivalent Shares of such Principal Party at
less than such then Current Per Share Market Price, or (ii) providing for any
special payment, tax or similar provision in connection with the issuance of the
Common Shares of such Principal Party pursuant to the provisions of Section 13
hereof, then, in such event, the Company hereby agrees with each holder of
Rights that it shall not consummate any such transaction unless prior thereto
the Company and such Principal Party shall have executed and delivered to the
Rights Agent a supplemental agreement providing that the provision in question
of such Principal Party shall have been canceled, waived or amended, or that the
authorized securities shall be redeemed, so that the applicable provision will
have no effect in connection with or as a consequence of, the consummation of
the proposed transaction.

               (e) The Company covenants and agrees that it shall not, at any
time after the Distribution Date, effect or permit to occur any Section 13
Event, if (i) at the time or immediately after such Section 13 Event there are
any rights, warrants or other instruments or securities outstanding or
agreements in effect which would substantially diminish or otherwise eliminate
the benefits intended to be afforded by the Rights, (ii) prior to,
simultaneously with or immediately after such Section 13 Event, the stockholders
of the Person who constitutes, or would constitute, the "Principal Party" for
purposes of Section 13(b) hereof shall have received a distribution of Rights
previously owned by such Person or any of its Affiliates or Associates or (iii)
the form or nature of organization of the Principal Party would preclude or
limit the exercisability of the Rights.

               (f) 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 Rights Certificates which evidence fractional Rights. In
lieu of such fractional Rights, there shall be paid to the registered holders of
the Rights 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, as determined pursuant to
the second sentence of Section 1(j) hereof.

               (b) The Company shall not be required to issue fractions of
Preferred Shares (other than fractions that are integral multiples of one
one-thousandth of a Preferred Share) upon exercise of the Rights or to
distribute certificates which evidence fractional Preferred Shares (other than
fractions that are integral multiples of one one-thousandth of a Preferred
Share). Interests in


                                      -25-
<PAGE>   29

fractions of Preferred Shares in integral multiples of one one-thousandth 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-thousandth of a Preferred
Share, the Company shall pay to the registered holders of Rights 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 a Preferred Share. For purposes
of this Section 14(b), the current market value of a Preferred Share shall be
the product equal to (x) one thousandth multiplied by (y) the closing price of a
Common Share of the Company (as determined pursuant to the second sentence of
Section 1(j) hereof) for the Trading Day immediately prior to the date of such
exercise.

               (c) The Company shall not be required to issue fractions of
Common Shares of the Company or to distribute certificates which evidence
fractional Common Shares of the Company upon the exercise or exchange of Rights.
In lieu of such fractional Common Shares of the Company, the Company shall pay
to the registered holders of Rights 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 a Common Share of the Company. For purposes of this
Section 14(c), the current market value of a Common Share of the Company shall
be the closing price of a Common Share of the Company (as determined pursuant to
the second sentence of Section 1(j) hereof) for the Trading Day immediately
prior to the date of such exercise.

               (d) The holder of a Right by the acceptance of the Right
expressly waives his or her right to receive any fractional Rights or any
fractional shares (other than fractions that are integral multiples of one
one-thousandth of a Preferred Share) upon exercise of a Right.

        Section 15. Rights of Action. All rights of action in respect of this
Agreement, excepting the rights of action given to the Rights Agent pursuant to
Section 18 hereof, are vested in the respective registered holders of the Rights
Certificates (and, prior to the Distribution Date, the registered holders of the
Common Shares); and any registered holder of any Rights 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 Rights Certificate (or, prior to the
Distribution Date, of the Common Shares), may, in his or her own behalf and for
his or her 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 or her right to exercise the Rights evidenced by such Rights Certificate in
the manner provided in such Rights Certificate and in this Agreement. Without
limiting the foregoing or any remedies available to the holders of Rights, it is
specifically acknowledged that the holders of Rights would not have an adequate
remedy at law for any breach of this Agreement and 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.


                                      -26-
<PAGE>   30

        Section 16. Agreement of Rights 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 Rights Certificates are
transferable only on the registry books of the Rights Agent if surrendered at
the principal office or offices of the Rights Agent designated for such
purposes, duly endorsed or accompanied by a proper instrument of transfer and
with the appropriate forms and certificates fully executed; and

               (c) subject to Sections 6(a) and 7(f) hereof, the Company and the
Rights Agent may deem and treat the person in whose name the Rights 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 Rights
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. Rights Certificate Holder Not Deemed a Stockholder. No
holder, as such, of any Rights Certificate shall be entitled to vote, receive
dividends or be deemed for any purpose to be 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 Rights Certificate be construed to confer upon the holder of any
Rights 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 specifically provided in Section 25 hereof), or to
receive dividends or subscription rights, or otherwise, until the Right or
Rights evidenced by such Rights Certificate shall have been exercised in
accordance with the provisions hereof.

        Section 18. Concerning the Rights Agent.

               (a) The Company agrees to pay to the Rights Agent 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 gross negligence, bad faith or
willful misconduct on the part of the Rights Agent, for anything done or omitted
by the Rights Agent in connection with the acceptance and administration of this
Agreement, including the costs and expenses of defending against any claim of
liability in the premises. In no event will the Rights Agent be liable for
special, indirect, incidental or consequential loss or damage of any kind
whatsoever, even if the Rights Agent has been advised of the possibility of such
loss or damage.


                                      -27-
<PAGE>   31

               (b) The Rights Agent shall be protected and shall incur no
liability for, or in respect of any action taken, suffered or omitted by it in
connection with, its administration of this Agreement in reliance upon any
Rights Certificate or certificate for Preferred Shares, for other securities of
the Company or for Common Shares, instrument of assignment or transfer, power of
attorney, endorsement, affidavit, letter, notice, direction, consent,
certificate, statement or other paper or document reasonably 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.

               (a) Any corporation into which the Rights Agent or any successor
Rights Agent may be merged or with which it may be consolidated, or any
corporation resulting from any merger or consolidation to which the Rights Agent
or any successor Rights Agent shall be a party, or any corporation succeeding to
the corporate trust business of the Rights Agent or any successor Rights Agent,
shall be the successor to the Rights Agent under this Agreement without the
execution or filing of any paper or any further act on the part of any of the
parties hereto; provided, however, 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 Rights 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 Rights
Certificates so countersigned; and in case at that time any of the Rights
Certificates shall not have been countersigned, any successor Rights Agent may
countersign such Rights 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 Rights Certificates shall have the full force provided in the Rights
Certificates and in this Agreement.

               (b) In case at any time the name of the Rights Agent shall be
changed and at such time any of the Rights Certificates shall have been
countersigned but not delivered, the Rights Agent may adopt the countersignature
under its prior name and deliver Rights Certificates so countersigned; and in
case at that time any of the Rights Certificates shall not have been
countersigned, the Rights Agent may countersign such Rights Certificates either
in its prior name or in its changed name; and in all such cases such Rights
Certificates shall have the full force provided in the Rights 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 which the Company and the holders of Rights Certificates,
by their acceptance thereof, shall be bound:

               (a) The Rights Agent 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.


                                      -28-
<PAGE>   32

               (b) Whenever in the performance of its duties under this
Agreement the Rights Agent shall deem it necessary or desirable that any fact or
matter (including, without limitation, the identity of any Acquiring Person and
the determination of Current Per Share Market Price) be proved or established by
the Company prior to taking or suffering any action hereunder, such fact or
matter (unless other evidence in respect thereof 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 Chief Financial Officer, the
Secretary or any Assistant 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 gross negligence, bad faith or willful
misconduct.

               (d) The Rights Agent shall not be liable for or by reason of any
of the statements of fact or recitals contained in this Agreement or in the
Rights 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 Rights 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 Rights Certificate;
nor shall it be responsible for any change in the exercisability of the Rights
or any adjustment in the terms of the Rights (including the manner, method or
amount thereof) provided for in Sections 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 Rights
Certificates after receipt by the Rights Agent of a certificate furnished
pursuant to Section 12 describing such change or adjustment); 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 Rights 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 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 Chief Executive Officer, the President,
any Vice President, the Chief Financial Officer, the Secretary or any Assistant
Secretary 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


                                      -29-
<PAGE>   33

those instructions. Any application by the Rights Agent for written instructions
from the Company may, at the option of the Rights Agent, set forth in writing
any action proposed to be taken or omitted by the Rights Agent under this Rights
Agreement and the date on and/or after which such action shall be taken or such
omission shall be effective. The Rights Agent shall not be liable for any action
taken by, or omission of, the Rights Agent in accordance with a proposal
included in any such application on or after the date specified in such
application (which date shall not be less than five (5) Business Days after the
date on which any officer of the Company actually receives such application,
unless any such officer shall have consented in writing to an earlier date)
unless, prior to taking any such action (or the effective date in the case of an
omission), the Rights Agent shall have received written instructions in response
to such application specifying the action to be taken or omitted.

               (h) The Rights Agent and any 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.

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

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

        Section 21. Change of Rights Agent. The Rights Agent or any successor
Rights Agent may resign and be discharged from its duties under this Agreement
upon thirty (30) days' notice in writing mailed to the Company and to each
transfer agent of the Preferred Shares and/or the Common Shares by registered or
certified mail, and to the holders of the Rights Certificates by first-class
mail. The Company may remove the Rights Agent or any successor Rights Agent upon
thirty (30) days' notice in writing, mailed to the Rights Agent or successor
Rights Agent, as the case may be, and to each transfer agent of the Preferred
Shares and/or the Common Shares by registered or


                                      -30-
<PAGE>   34

certified mail, and to the holders of the Rights Certificates by first-class
mail. If the Rights Agent shall resign or be removed or shall otherwise become
incapable of acting, the Company shall appoint a successor to the Rights Agent.
If the Company shall fail to make such appointment within a period of thirty
(30) days after giving notice of such removal or after it has been notified in
writing of such resignation or incapacity by the resigning or incapacitated
Rights Agent or by the holder of a Rights Certificate (who shall, with such
notice, submit his or her Rights Certificate for inspection by the Company),
then the registered holder of any Rights 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 any state of the United States, in good standing, which is authorized under
such laws to exercise corporate trust or stockholder services powers and is
subject to supervision or examination by federal or state authority and which
has at the time of its appointment as Rights Agent a combined capital and
surplus of at least $100 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 Preferred Shares and/or the Common Shares, and mail a notice thereof in
writing to the registered holders of the Rights 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 Rights Certificates. Notwithstanding any of
the provisions of this Agreement or of the Rights to the contrary, the Company
may, at its option, issue new Rights Certificates evidencing Rights in such form
as may be approved by its Board of Directors to reflect any adjustment or change
in the Exercise Price and the number or kind or class of shares or other
securities or property purchasable under the Rights Certificates made in
accordance with the provisions of this Agreement. In addition, in connection
with the issuance or sale of Common Shares following the Distribution Date and
prior to the redemption or expiration of the Rights, the Company (a) shall, with
respect to Common Shares so issued or sold pursuant to the exercise of stock
options or under any employee plan or arrangement or upon the exercise,
conversion or exchange of other securities of the Company outstanding at the
date hereof or upon the exercise, conversion or exchange of securities
hereinafter issued by the Company and (b) may, in any other case, if deemed
necessary or appropriate by the Board of Directors of the Company, issue Rights
Certificates representing the appropriate number of Rights in connection with
such issuance or sale; provided, however, that (i) no such Rights Certificate
shall be issued and this sentence shall be null and void ab initio if, and to
the extent that, such issuance or this sentence would create a significant risk
of or result in material adverse tax consequences to the Company or the Person
to whom such Rights Certificate would be issued or would create a significant
risk of or result in such options' or employee plans' or arrangements' failing
to qualify for otherwise available special tax treatment and (ii) no such Rights
Certificate shall be issued if, and to the extent that, appropriate adjustment
shall otherwise have been made in lieu of the issuance thereof.


                                      -31-
<PAGE>   35

        Section 23. Redemption.

               (a) The Company may, at its option and with the approval of the
Board of Directors, at any time prior to the Close of Business on the earlier of
(i) the fifth day following the Shares Acquisition Date (or such later date as
may be determined by action of the Company's Board of Directors and publicly
announced by the Company) and (ii) the Final Expiration Date, redeem all but not
less than all the then outstanding Rights at a redemption price of $0.001 per
Right, appropriately adjusted to reflect any stock split, stock dividend or
similar transaction occurring after the date hereof (such redemption price being
herein referred to as the "REDEMPTION PRICE") and the Company may, at its
option, pay the Redemption Price either in Common Shares of the Company (based
on the Current Per Share Market Price thereof at the time of redemption) or
cash. Such redemption of the Rights by the Company 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. The date on which the Board of Directors elects
to make the redemption effective shall be referred to as the "REDEMPTION DATE."

               (b) Immediately upon the action of the Board of Directors of the
Company ordering the redemption of the Rights, evidence of which shall have been
filed with the Rights Agent, 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 ten (10) days after the action of
the Board of Directors ordering the redemption of the Rights, the Company shall
give notice of such redemption to the Rights Agent and the holders of the then
outstanding Rights by mailing such notice to all such holders at their last
addresses as they appear upon the registry books of the Rights Agent or, prior
to the Distribution Date, on the registry books of any transfer agent for the
Common Shares or those of Exchangeco. Any notice which is mailed in the manner
herein provided shall be deemed given, whether or not the holder receives the
notice. Each such notice of redemption will state the method by which the
payment of the Redemption Price will be made. Neither the Company nor any of its
Affiliates or Associates may redeem, acquire or purchase for value any Rights at
any time in any manner other than that specifically set forth in this Section 23
or in Section 24 hereof, and other than in connection with the purchase or
acquisition of Common Shares prior to the Distribution Date.

        Section 24. Exchange.

               (a) Subject to applicable laws, rules and regulations, and
subject to subsection 24(c) below, the Company may, at its option, by action of
the Board of Directors, at any time after the occurrence of a Triggering Event,
exchange all or part of the then outstanding and exercisable Rights (which shall
not include Rights that have become void pursuant to the provisions of Section
7(e) hereof) for Common Shares of the Company at an exchange ratio of one Common
Share of the Company per Right, appropriately adjusted to reflect any stock
split, stock dividend or similar transaction occurring after the date hereof
(such exchange ratio being hereinafter referred to as the "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


                                      -32-
<PAGE>   36

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 of the Company
then outstanding.

               (b) Immediately upon the action of the Board of Directors
ordering the exchange of any Rights pursuant to subsection 24(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 of the Company equal to
the number of such Rights held by such holder multiplied by the Exchange Ratio.
The Company shall 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 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 of the Company for Rights will be effected and, in the
event of any partial exchange, the number of Rights which will be exchanged. Any
partial exchange shall be effected pro rata based on the number of Rights (other
than Rights which have become void pursuant to the provisions of Section 7(e)
hereof) held by each holder of Rights.

               (c) In the event that there shall not be sufficient Common Shares
of the Company issued but not outstanding or authorized but unissued to permit
any exchange of Rights as contemplated in accordance with Section 24(a), the
Company shall either take such action as may be necessary to authorize
additional Common Shares of the Company for issuance upon exchange of the Rights
or alternatively, at the option of a majority of the Board of Directors, with
respect to each Right (i) pay cash in an amount equal to the Current Value (as
hereinafter defined), in lieu of issuing Common Shares of the Company in
exchange therefor, or (ii) issue debt or equity securities or a combination
thereof, having a value equal to the Current Value, in lieu of issuing Common
Shares of the Company in exchange for each such Right, where the value of such
securities shall be determined by a nationally recognized investment banking
firm selected by majority vote of the Board of Directors, or (iii) deliver any
combination of cash, property, Common Shares of the Company and/or other
securities having a value equal to the Current Value in exchange for each Right.
For purposes of this Section 24(c) only, the Current Value shall mean the
product of the Current Per Share Market Price of Common Shares of the Company on
the date of the occurrence of the event described above in subparagraph (a),
multiplied by the number of Common Shares of the Company for which the Right
otherwise would be exchangeable if there were sufficient shares available. To
the extent that the Company determines that some action need be taken pursuant
to clauses (i), (ii) or (iii) of this Section 24(c), the Board of Directors may
temporarily suspend the exercisability of the Rights for a period of up to sixty
(60) days following the date on which the event described in Section 24(a) shall
have occurred, in order to seek any authorization of additional Common Shares of
the Company and/or to decide the appropriate form of distribution to be made
pursuant to the above provision and to determine the value thereof. In the event
of any such suspension, the Company shall issue a public announcement stating
that the exercisability of the Rights has been temporarily suspended.


                                      -33-
<PAGE>   37

               (d) The Company shall not be required to issue fractions of
Common Shares of the Company or to distribute certificates which evidence
fractional Common Shares of the Company. In lieu of such fractional Common
Shares of the Company, there shall be paid to the registered holders of the
Rights Certificates with regard to which such fractional Common Shares of the
Company would otherwise be issuable, an amount in cash equal to the same
fraction of the current market value of a whole Common Share of the Company (as
determined pursuant to the second sentence of Section 1(j) hereof).

               (e) The Company may, at its option, by majority vote of the Board
of Directors, at any time before any Person has become an Acquiring Person,
exchange all or part of the then outstanding Rights for rights of substantially
equivalent value, as determined reasonably and with good faith by the Board of
Directors based upon the advice of one or more nationally recognized investment
banking firms.

               (f) Immediately upon the action of the Board of Directors
ordering the exchange of any Rights pursuant to subsection 24(e) 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 rights in exchange therefor as has
been determined by the Board of Directors in accordance with subsection 24(e)
above. The Company shall 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 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 any transfer agent for the Common Shares
or those of Exchangeco. 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 Rights
will be effected.

        Section 25. Notice of Certain Events.

               (a) In case the Company shall propose to effect or permit to
occur any Triggering Event or Section 13 Event, the Company shall give notice
thereof to each holder of Rights in accordance with Section 26 hereof at least
twenty (20) days prior to occurrence of such Triggering Event or such Section 13
Event.

               (b) In case any Triggering Event or Section 13 Event shall occur,
then, in any such case, the Company shall as soon as practicable thereafter give
to each holder of a Rights Certificate, in accordance with Section 26 hereof, a
notice of the occurrence of such event, which shall specify the event and the
consequences of the event to holders of Rights under Sections 11(a)(ii) and 13
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 Rights Certificate
to or on the Company shall be sufficiently given or made if sent by first-class
mail, postage prepaid, addressed (until another address is filed in writing with
the Rights Agent) as follows:


                                      -34-
<PAGE>   38

                             Critical Path, Inc.
                             320 First Street
                             San Francisco, CA  94105

                             with a copy to:
                             Wilson Sonsini Goodrich & Rosati
                             Professional Corporation
                             650 Page Mill Road
                             Palo Alto, California 94304-1050
                             Attn: David J. Berger

        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 Rights Certificate to or on the Rights Agent shall be sufficiently given
or made if sent by first-class mail, postage prepaid, addressed (until another
address is filed in writing with the Company) as follows:

                             Computershare Trust Company, Inc.
                             12039 West Alameda Parkway
                             Suite Z2
                             Lakewood, CO 80228

                             Attention: John Harmann

Notices or demands authorized by this Agreement to be given or made by the
Company or the Rights Agent to the holder of any Rights 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.

        Section 27. Supplements and Amendments. Prior to the occurrence of a
Distribution Date, the Company may supplement or amend this Agreement in any
respect without the approval of any holders of Rights and the Rights Agent
shall, if the Company so directs, execute such supplement or amendment. From and
after the occurrence of a Distribution Date, the Company and the Rights Agent
may from time to time supplement or amend this Agreement without the approval of
any holders of Rights in order to (i) cure any ambiguity, (ii) correct or
supplement any provision contained herein which may be defective or inconsistent
with any other provisions herein, (iii) shorten or lengthen any time period
hereunder or (iv) to change or supplement the provisions hereunder in any manner
that the Company may deem necessary or desirable and that shall not adversely
affect the interests of the holders of Rights (other than an Acquiring Person or
an Affiliate or Associate of an Acquiring Person); provided, this Agreement may
not be supplemented or amended to lengthen, pursuant to clause (iii) of this
sentence, (A) a time period relating to when the Rights may be redeemed at such
time as the Rights are not then redeemable or (B) any other time period unless
such lengthening is for the purpose of protecting, enhancing or clarifying the
rights of, and/or the benefits to, the holders of Rights (other than an
Acquiring Person or an Affiliate or Associate of an Acquiring Person). Upon the
delivery of a certificate from an appropriate officer of the Company that states
that the proposed supplement or amendment is in compliance with the terms


                                      -35-
<PAGE>   39

of this Section 27, the Rights Agent shall execute such supplement or amendment.
Prior to the Distribution Date, the interests of the holders of Rights shall be
deemed coincident with the interests of the holders of Common Shares.

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

        Section 29. Determinations and Actions by the Board of Directors, etc.
For all purposes of this Agreement, any calculation of the number of Common
Shares of the Company outstanding at any particular time, including for purposes
of determining the particular percentage of such outstanding Common Shares of
the Company of which any Person is the Beneficial Owner, shall be made in
accordance with the last sentence of Rule 13d-3(d)(1)(i) of the General Rules
and Regulations under the Exchange Act; provided, however, that the number of
Common Shares of the Company outstanding at any particular time will include the
aggregate number of Common Shares of the Company issuable upon exchange of all
Exchangeable Shares outstanding at that particular time. The Board of Directors
of the Company shall have the exclusive power and authority to administer this
Agreement and to exercise all rights and powers specifically granted to the
Board, or the Company, or as may be necessary or advisable in the administration
of this Agreement, including, without limitation, the right and power (i) to
interpret the provisions of this Agreement and (ii) to make all determinations
deemed necessary or advisable for the administration of this Agreement
(including a determination to redeem or not redeem the Rights or to amend the
Agreement). All such actions, calculations, interpretations and determinations
(including, for purposes of clause (y) below, all omissions with respect to the
foregoing) which are done or made by the Board in good faith, shall (x) be
final, conclusive and binding on the Company, the Rights Agent, the holders of
the Rights Certificates and all other parties and (y) not subject the Board to
any liability to the holders of the Rights.

        Section 30. Benefits of this Agreement. Nothing in this Agreement shall
be construed to give to any Person other than the Company, the Rights Agent and
the registered holders of the Rights Certificates (and, prior to the
Distribution Date, the Common Shares) any legal or equitable right, remedy or
claim pursuant to 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 Rights Certificates (and, prior to the Distribution Date, the Common
Shares).

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


                                      -36-
<PAGE>   40

        Section 32. Governing Law. This Agreement and each Right and each Rights
Certificate issued hereunder shall be deemed to be a contract made under the
laws of the State of California 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 33. Counterparts. This Agreement may be executed in any number
of counterparts and each of such counterparts shall for all purposes be deemed
to be an original, and all such counterparts shall together constitute but one
and the same instrument.

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




                                      -37-
<PAGE>   41

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

"COMPANY"                           CRITICAL PATH, INC.

                                    By:/s/ BRETT M. ROBERTSON
                                       ----------------------------------------

                                    Name: Brett M. Robertson
                                         --------------------------------------

                                    Title: VP Strategic Developement
                                          -------------------------------------
                                              and General Counsel



"RIGHTS AGENT"                      COMPUTERSHARE TRUST COMPANY, INC.

                                    By:/s/ L. YEWLER
                                       ----------------------------------------

                                    Name: L. Yewler
                                         --------------------------------------

                                    Title: President
                                          -------------------------------------




"RIGHTS AGENT"                      COMPUTERSHARE TRUST COMPANY, INC.

                                    By: /s/ DEBORAH SORHEIM
                                       ----------------------------------------

                                    Name: Deborah Sorheim
                                         --------------------------------------

                                    Title: Secretary / Treasurer
                                          -------------------------------------


<PAGE>   42
                                    EXHIBIT A

               CERTIFICATE OF DETERMINATION OF RIGHTS, PREFERENCES
                                AND PRIVILEGES OF
                     SERIES C PARTICIPATING PREFERRED STOCK
                             OF CRITICAL PATH, INC.


        The undersigned, Lawrence P. Reinhold and Brett M. Robertson, do hereby
certify:

        1. That they are the duly elected and acting Executive Vice President
and Chief Financial Officer and Secretary, respectively, of Critical Path, Inc.,
a California corporation (the "CORPORATION").

        2. That pursuant to the authority conferred upon the Board of Directors
by the Amended and Restated Articles of Incorporation of the said Corporation,
the said Board of Directors on March 19, 2001 adopted the following resolution
creating a series of 75,000 shares of Preferred Stock designated as Series C
Participating Preferred Stock:

        "RESOLVED, that pursuant to the authority vested in the Board of
Directors of the corporation by the Restated Certificate of Incorporation, the
Board of Directors does hereby provide for the issue of a series of Preferred
Stock of the Corporation and does hereby fix and herein state and express the
Determinations, powers, preferences and relative and other special rights and
the qualifications, limitations and restrictions of such series of Preferred
Stock as follows:

        Section 1. Determination and Amount. The shares of such series shall be
designated as "SERIES C PARTICIPATING PREFERRED STOCK." The Series C
Participating Preferred Stock shall have a par value of $0.001 per share, and
the number of shares constituting such series shall be 75,000.

        Section 2. Proportional Adjustment. In the event that the Corporation
shall at any time after the issuance of any share or shares of Series C
Participating Preferred Stock (i) declare any dividend on Common Stock of the
Corporation ("COMMON STOCK") payable in shares of Common Stock, (ii) subdivide
the outstanding Common Stock or (iii) combine the outstanding Common Stock into
a smaller number of shares, then in each such case the Corporation shall
simultaneously effect a proportional adjustment to the number of outstanding
shares of Series C Participating Preferred Stock.

        Section 3. Dividends and Distributions.

               (a) Subject to the prior and superior right of the holders of any
shares of any series of Preferred Stock ranking prior and superior to the shares
of Series C Participating Preferred Stock with respect to dividends, the holders
of shares of Series C Participating Preferred Stock shall be entitled to receive
when, as and if declared by the Board of Directors out of funds legally
available for the purpose, quarterly dividends payable in cash on the last day
of February, May, August and November in each year (each such date being
referred to herein as a "QUARTERLY

<PAGE>   43
DIVIDEND PAYMENT DATE"), commencing on the first Quarterly Dividend Payment Date
after the first issuance of a share or fraction of a share of Series C
Participating Preferred Stock, in an amount per share (rounded to the nearest
cent) equal to 1,000 times the aggregate per share amount of all cash dividends,
and 1,000 times the aggregate per share amount (payable in kind) of all non-cash
dividends or other distributions other than a dividend payable in shares of
Common Stock or a subdivision of the outstanding shares of Common Stock (by
reclassification or otherwise), declared on the Common Stock since the
immediately preceding Quarterly Dividend Payment Date, or, with respect to the
first Quarterly Dividend Payment Date, since the first issuance of any share or
fraction of a share of Series C Participating Preferred Stock.

               (b) The Corporation shall declare a dividend or distribution on
the Series C Participating Preferred Stock as provided in paragraph (a) above
immediately after it declares a dividend or distribution on the Common Stock
(other than a dividend payable in shares of Common Stock).

               (c) Dividends shall begin to accrue on outstanding shares of
Series C Participating Preferred Stock from the Quarterly Dividend Payment Date
next preceding the date of issue of such shares of Series C Participating
Preferred Stock, unless the date of issue of such shares is prior to the record
date for the first Quarterly Dividend Payment Date, in which case dividends on
such shares shall begin to accrue from the date of issue of such shares, or
unless the date of issue is a Quarterly Dividend Payment Date or is a date after
the record date for the determination of holders of shares of Series C
Participating Preferred Stock entitled to receive a quarterly dividend and
before such Quarterly Dividend Payment Date, in either of which events such
dividends shall begin to accrue from such Quarterly Dividend Payment Date.
Accrued but unpaid dividends shall not bear interest. Dividends paid on the
shares of Series C Participating Preferred Stock in an amount less than the
total amount of such dividends at the time accrued and payable on such shares
shall be allocated pro rata on a share-by-share basis among all such shares at
the time outstanding. The Board of Directors may fix a record date for the
determination of holders of shares of Series C Participating Preferred Stock
entitled to receive payment of a dividend or distribution declared thereon,
which record date shall be no more than 30 days prior to the date fixed for the
payment thereof.

        Section 4. Voting Rights. The holders of shares of Series C
Participating Preferred Stock shall have the following voting rights:

               (a) Each share of Series C Participating Preferred Stock shall
entitle the holder thereof to 1,000 votes on all matters submitted to a vote of
the stockholders of the Corporation.

               (b) Except as otherwise provided herein or by law, the holders of
shares of Series C Participating Preferred Stock and the holders of shares of
Common Stock shall vote together as one class on all matters submitted to a vote
of stockholders of the Corporation.

               (c) Except as required by law, the holders of Series C
Participating Preferred Stock shall have no special voting rights and their
consent shall not be required (except to the extent



                                      -2-
<PAGE>   44
that they are entitled to vote with holders of Common Stock as set forth herein)
for taking any corporate action.

        Section 5. Certain Restrictions.

               (a) The Corporation shall not declare any dividend on, make any
distribution on, or redeem or purchase or otherwise acquire for consideration
any shares of Common Stock after the first issuance of a share or fraction of a
share of Series C Participating Preferred Stock unless concurrently therewith it
shall declare a dividend on the Series C Participating Preferred Stock as
required by Section 3 hereof.

               (b) Whenever quarterly dividends or other dividends or
distributions payable on the Series C Participating Preferred Stock as provided
in Section 3 are in arrears, thereafter and until all accrued and unpaid
dividends and distributions, whether or not declared, on shares of Series C
Participating Preferred Stock outstanding shall have been paid in full, the
Corporation shall not

                      (i) declare or pay dividends on, make any other
distributions on, or redeem or purchase or otherwise acquire for consideration
any shares of stock ranking junior (either as to dividends or upon liquidation,
dissolution or winding up) to the Series C Participating Preferred Stock;

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

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

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

               (c) The Corporation shall not permit any subsidiary of the
Corporation to purchase or otherwise acquire for consideration any shares of
stock of the Corporation unless the



                                      -3-
<PAGE>   45
Corporation could, under paragraph (a) of this Section 5, purchase or otherwise
acquire such shares at such time and in such manner.

        Section 6. Reacquired Shares. Any shares of Series C Participating
Preferred Stock purchased or otherwise acquired by the Corporation in any manner
whatsoever shall be retired and canceled promptly after the acquisition thereof.
All such shares shall upon their cancellation become authorized but unissued
shares of Preferred Stock and may be reissued as part of a new series of
Preferred Stock to be created by resolution or resolutions of the Board of
Directors, subject to the conditions and restrictions on issuance set forth
herein and in the Restated Certificate of Incorporation, as then amended.

        Section 7. Liquidation, Dissolution or Winding Up. Upon any liquidation,
dissolution or winding up of the Corporation, the holders of shares of Series C
Participating Preferred Stock shall be entitled to receive an aggregate amount
per share equal to 1,000 times the aggregate amount to be distributed per share
to holders of shares of Common Stock plus an amount equal to any accrued and
unpaid dividends on such shares of Series C Participating Preferred Stock.

        Section 8. Consolidation, Merger, etc. In case the Corporation shall
enter into any consolidation, merger, combination or other transaction in which
the shares of Common Stock are exchanged for or changed into other stock or
securities, cash and/or any other property, then in any such case the shares of
Series C Participating Preferred Stock shall at the same time be similarly
exchanged or changed in an amount per share equal to 1,000 times the aggregate
amount of stock, securities, cash and/or any other property (payable in kind),
as the case may be, into which or for which each share of Common Stock is
changed or exchanged.

        Section 9. No Redemption. The shares of Series C Participating Preferred
Stock shall not be redeemable.

        Section 10. Ranking. The Series C Participating Preferred Stock shall
rank junior to all other series of the Corporation's Preferred Stock as to the
payment of dividends and the distribution of assets, unless the terms of any
such series shall provide otherwise.

        Section 11. Amendment. The Amended and Restated Articles of
Incorporation of the Corporation shall not be further amended in any manner
which would materially alter or change the powers, preference or special rights
of the Series C Participating Preferred Stock so as to affect them adversely
without the affirmative vote of the holders of a majority of the outstanding
shares of Series C Participating Preferred Stock, voting separately as a series.

        Section 12. Fractional Shares. Series C Participating Preferred Stock
may be issued in fractions of a share which shall entitle the holder, in
proportion to such holder's fractional shares, to exercise voting rights,
receive dividends, participate in distributions and to have the benefit of all
other rights of holders of Series C Participating Preferred Stock.




                                      -4-
<PAGE>   46
        RESOLVED FURTHER, that the President, any Vice President or Chief
Operating Officer and the Secretary or any Assistant Secretary of this
corporation be, and they hereby are, authorized and directed to prepare and file
a Certificate of Determination of Rights, Preferences and Privileges in
accordance with the foregoing resolution and the provisions of California law
and to take such actions as they may deem necessary or appropriate to carry out
the intent of the foregoing resolution."

        I further declare under penalty of perjury that the matters set forth in
the foregoing Certificate of Determination are true and correct of my own
knowledge.

        Executed at San Francisco, California on May 2, 2001.


                                       -----------------------------------------
                                       Lawrence P. Reinhold
                                       Executive Vice President and
                                       Chief Financial Officer



                                       -----------------------------------------
                                       Brett M. Robertson
                                       Secretary



                                      -5-
<PAGE>   47
                                    EXHIBIT B

                           FORM OF RIGHTS CERTIFICATE



Certificate No. R-                                              _________ Rights


        NOT EXERCISABLE AFTER THE EARLIER OF (i) MAY 15, 2011, (ii) THE DATE
        TERMINATED BY THE COMPANY OR (iii) THE DATE THE COMPANY EXCHANGES THE
        RIGHTS PURSUANT TO THE RIGHTS AGREEMENT. THE RIGHTS ARE SUBJECT TO
        REDEMPTION, AT THE OPTION OF THE COMPANY, AT $0.001 PER RIGHT ON THE
        TERMS SET FORTH IN THE RIGHTS AGREEMENT. UNDER CERTAIN CIRCUMSTANCES,
        RIGHTS BENEFICIALLY OWNED BY AN ACQUIRING PERSON OR AN AFFILIATE OR
        ASSOCIATE OF AN ACQUIRING PERSON (AS SUCH TERMS ARE DEFINED IN THE
        RIGHTS AGREEMENT) AND ANY SUBSEQUENT HOLDER OF SUCH RIGHTS MAY BECOME
        NULL AND VOID. [THE RIGHTS REPRESENTED BY THIS RIGHTS CERTIFICATE ARE OR
        WERE BENEFICIALLY OWNED BY A PERSON WHO WAS OR BECAME AN ACQUIRING
        PERSON OR AN AFFILIATE OR ASSOCIATE OF AN ACQUIRING PERSON (AS SUCH
        TERMS ARE DEFINED IN THE RIGHTS AGREEMENT). ACCORDINGLY, THIS RIGHTS
        CERTIFICATE AND THE RIGHTS REPRESENTED HEREBY MAY BECOME NULL AND VOID
        IN THE CIRCUMSTANCES SPECIFIED IN SECTION 7(e) OF SUCH RIGHTS
        AGREEMENT.]*


                               RIGHTS CERTIFICATE


                               CRITICAL PATH, 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 March 19, 2001, (the "RIGHTS AGREEMENT"),
between Critical Path, Inc., a California corporation (the "COMPANY"), and
Computershare Trust Company, Inc. ( the "RIGHTS AGENT"), to purchase from the
Company at any time after the Distribution Date (as such term is defined in the
Rights Agreement) and prior to



--------

* The portion of the legend in bracket shall be inserted only if applicable
and shall replace the preceding sentence.
<PAGE>   48
5:00 P.M., New York time, on May 15, 2011 at the office of the Rights Agent
designated for such purpose, or at the office of its successor as Rights Agent,
one one-thousandth (1/1,000) of a fully paid and non-assessable share of Series
C Participating Preferred Stock, par value $0.001 per share (the "PREFERRED
SHARES"), of the Company, at an Exercise Price of $25.00 per one-thousandth of a
Preferred Share (the "EXERCISE PRICE"), upon presentation and surrender of this
Rights Certificate with the Form of Election to Purchase and related Certificate
duly executed. The number of Rights evidenced by this Rights Certificate (and
the number of one-thousandths of a Preferred Share which may be purchased upon
exercise hereof) set forth above are the number and Exercise Price as of May 15,
2001 based on the Preferred Shares as constituted at such date. As provided in
the Rights Agreement, the Exercise Price and the number and kind of Preferred
Shares or other securities which may be purchased upon the exercise of the
Rights evidenced by this Rights Certificate are subject to modification and
adjustment upon the happening of certain events.

               This Rights 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 Rights Certificates,
which limitations of rights include the temporary suspension of the
exercisability of such Rights under the specific circumstances set forth in the
Rights Agreement. Copies of the Rights Agreement are on file at the principal
executive offices of the Company and the above-mentioned office of the Rights
Agent.

               Subject to the provisions of the Rights Agreement, the Rights
evidenced by this Rights Certificate (i) may be redeemed by the Company, at its
option, at a redemption price of $0.001 per Right or (ii) may be exchanged by
the Company in whole or in part for Common Shares of the Company, substantially
equivalent rights or other consideration as determined by the Company.

               This Rights Certificate, with or without other Rights
Certificates, upon surrender at the office of the Rights Agent designated for
such purpose, may be exchanged for another Rights Certificate or Rights
Certificates of like tenor and date evidencing Rights entitling the holder to
purchase a like aggregate amount of securities as the Rights evidenced by the
Rights Certificate or Rights Certificates surrendered shall have entitled such
holder to purchase. If this Rights Certificate shall be exercised in part, the
holder shall be entitled to receive upon surrender hereof another Rights
Certificate or Rights Certificates for the number of whole Rights not exercised.

               No fractional portion of less than one one-thousandth of a
Preferred Share will be issued upon the exercise of any Right or Rights
evidenced hereby but in lieu thereof a cash payment will be made, as provided in
the Rights Agreement.

               No holder of this Rights Certificate, as such, 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



                                      -2-
<PAGE>   49
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 Rights Certificate shall have been
exercised as provided in the Rights Agreement.

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



                                      -3-
<PAGE>   50

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

Dated as of                 ,      .
             ---------------  -----

ATTEST:                                CRITICAL PATH, INC.


                                       By:
----------------------------              -------------------------------------
Secretary

                                       Its:
                                           -------------------------------------

Countersigned:

Computershare Trust Company, Inc.
as Rights Agent

By:
   -------------------------------


Its:
   -------------------------------




<PAGE>   51
                   FORM OF REVERSE SIDE OF RIGHTS CERTIFICATE

                               FORM OF ASSIGNMENT

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


        FOR VALUE RECEIVED _______________ hereby sells, assigns and transfers
unto

--------------------------------------------------------------------------------
                  (Please print name and address of transferee)

--------------------------------------------------------------------------------
this Rights Certificate, together with all right, title and interest therein,
and does hereby irrevocably constitute and appoint __________________________
Attorney, to transfer the within Rights 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.

<PAGE>   52
                                   CERTIFICATE

        The undersigned hereby certifies by checking the appropriate boxes that:

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

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


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.
<PAGE>   53
             FORM OF REVERSE SIDE OF RIGHTS CERTIFICATE -- CONTINUED

                          FORM OF ELECTION TO PURCHASE

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


To:___________________________

               The undersigned hereby irrevocably elects to exercise
_________________________ Rights represented by this Rights Certificate to
purchase the number of one-thousandths of a Preferred Share issuable upon the
exercise of such Rights and requests that certificates for such number of
one-thousandths of a Preferred Share 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 Rights
Certificate, a new Rights 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.

<PAGE>   54
                                   CERTIFICATE


        The undersigned hereby certifies by checking the appropriate boxes that:

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

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

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.
<PAGE>   55
             FORM OF REVERSE SIDE OF RIGHTS CERTIFICATE -- CONTINUED

                                     NOTICE


               The signature in the foregoing Forms of Assignment and Election
must conform to the name as written upon the face of this Rights Certificate in
every particular, without alteration or enlargement or any change whatsoever.

<PAGE>   56
                                    EXHIBIT C

                             SHAREHOLDER RIGHTS PLAN
                               CRITICAL PATH, INC.

                                SUMMARY OF RIGHTS

DISTRIBUTION AND                     The Board of Directors has (i) declared a
TRANSFER OF RIGHTS;                  dividend of one Right for each share of
RIGHTS CERTIFICATE:                  Common Stock of Critical Path, Inc. (the
                                     "COMPANY") outstanding and (ii) authorized
                                     the issuance to each holder of Class A
                                     Non-Voting Preference Shares ("EXCHANGEABLE
                                     SHARES") of Critical Path Messaging Co., a
                                     Canadian subsidiary of the Company
                                     ("EXCHANGECO"), of one Right for each
                                     Exchangeable Share held. Each Exchangeable
                                     Share is exchangeable for one share of the
                                     Company' Common Stock. Prior to the
                                     Distribution Date referred to below, the
                                     Rights will be evidenced by and trade with
                                     the certificates for the Common Stock and
                                     Exchangeable Shares. After the Distribution
                                     Date, the Company will mail Rights
                                     certificates to the Company's stockholders
                                     and the holders of the Exchangeable Shares.
                                     The Rights will become transferable apart
                                     from the Common Stock and Exchangeable
                                     Shares.

DISTRIBUTION DATE:                   Rights will separate from the Common Stock
                                     and Exchangeable Shares and become
                                     exercisable following (a) the tenth
                                     business day (or such later date as may be
                                     determined by the Company's Board of
                                     Directors) after a person or group acquires
                                     beneficial ownership of 15% or more of the
                                     Company's Common Stock or (b) the tenth
                                     business day (or such later date as may be
                                     determined by the Company's Board of
                                     Directors) after a person or group
                                     announces a tender or exchange offer, the
                                     consummation of which would result in
                                     beneficial ownership by a person or group
                                     of 15% or more of the Company's Common
                                     Stock. For the purposes hereof, "beneficial
                                     ownership" shall be calculated in
                                     accordance with Section 13(d) of the
                                     Securities Exchange Act of 1934, as
                                     amended, and Rule 13d-3 thereunder (or any
                                     comparable or successor law or regulation),
                                     and includes shares of Common Stock
                                     issuable upon exercise of certain
                                     securities, including the Exchangeable
                                     Shares.

PREFERRED STOCK                      After the Distribution Date, each Right
PURCHASABLE UPON                     will entitle the holder to purchase for
EXERCISE OF RIGHTS:                  $25.00 (the "EXERCISE PRICE"), a fraction
                                     of a share of the Company's Preferred Stock
                                     with economic terms similar to that of one
                                     share of the Company's Common Stock.

FLIP-IN:                             If an acquiror (an "ACQUIRING PERSON")
                                     obtains beneficial ownership of 15% or more
                                     of the Company's Common Stock, then each
                                     Right (other than Rights owned by an
                                     Acquiring Person or its affiliates) will
                                     entitle the holder thereof to purchase, for
                                     the Exercise Price, a number of shares of
                                     the Company's Common Stock having a
                                     then-current market value of twice the
                                     Exercise Price.

FLIP-OVER:                           If, after an Acquiring Person obtains
                                     beneficial ownership of 15% or more of the
                                     Company's Common Stock, (a) the Company
                                     merges into another entity, (b) an
                                     acquiring entity merges into the Company or
                                     (c) the Company sells more than 50% of the
                                     Company's assets or earning power, then
                                     each Right

<PAGE>   57
                                     (other than Rights owned by an Acquiring
                                     Person or its affiliates) will entitle the
                                     holder thereof to purchase, for the
                                     Exercise Price, a number of shares of
                                     Common Stock of the person engaging in the
                                     transaction having a then current market
                                     value of twice the Exercise Price.

EXCHANGE PROVISION:                  At any time after the date on which an
                                     Acquiring Person obtains beneficial
                                     ownership of 15% or more of the Company's
                                     Common Stock and prior to the acquisition
                                     by the Acquiring Person of beneficial
                                     ownership of 50% of the outstanding Common
                                     Stock, a majority of the Board of Directors
                                     and the Board of Directors of the Company
                                     may exchange the Rights (other than Rights
                                     owned by the Acquiring Person or its
                                     affiliates), in whole or in part, for
                                     shares of Common Stock of the Company at an
                                     exchange ratio of one share of Common Stock
                                     per Right (subject to adjustment).

REDEMPTION OF THE                    Rights will be redeemable at the Company's
RIGHTS:                              option for $0.001 per Right at any time on
                                     or prior to the fifth day (or such later
                                     date as may be determined by the Company's
                                     Board of Directors) after public
                                     announcement that a Person has acquired
                                     beneficial ownership of 15% or more of the
                                     Company's Common Stock (the "SHARES
                                     ACQUISITION DATE").

EXPIRATION OF THE                    The Rights expire on the earliest of (a)
RIGHTS:                              May 15, 2011 or (b) exchange or redemption
                                     of the Rights as described above.

AMENDMENT OF TERMS                   The terms of the Rights and the Rights
OF RIGHTS:                           Agreement may be amended in any respect
                                     without the consent of the Rights holders
                                     on or prior to the Distribution Date;
                                     thereafter, the terms of the Rights and the
                                     Rights Agreement may be amended without the
                                     consent of the Rights holders in order to
                                     cure any ambiguities or to make changes
                                     which do not adversely affect the interests
                                     of Rights holders (other than the Acquiring
                                     Person).

VOTING RIGHTS:                       Rights will not have any voting rights.

ANTI-DILUTION                        Rights will have the benefit of certain
PROVISIONS:                          customary anti-dilution provisions.

TAXES:                               The Rights distribution should not be
                                     taxable for U.S. federal or Canadian
                                     federal income tax purposes. However,
                                     following an event which renders the Rights
                                     exercisable or upon redemption of the
                                     Rights, stockholders may recognize taxable
                                     income.

The foregoing is a summary of certain principal terms of the Stockholder Rights
Plan. It may be amended from time to time. A copy of the Rights Agreement will
be filed with the Securities and Exchange Commission as an Exhibit to a
Registration Statement on Form 8-A dated May 4, 2001. A copy of the Rights
Agreement is available free of charge from the Company.



                                      -2-