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                                                                     EXHIBIT 4.4

                                      WYETH

              FLOATING RATE CONVERTIBLE SENIOR DEBENTURES DUE 2024

                          REGISTRATION RIGHTS AGREEMENT

                                                               December 16, 2003

Citigroup Global Markets Inc. and
J.P. Morgan Securities Inc.
As representatives of the several Purchasers
  named in Schedule I to the Purchase Agreement

Ladies and Gentlemen:

         Wyeth, a Delaware corporation (the "Company"), proposes to issue and
sell to the Purchasers (as defined herein) upon the terms set forth in the
Purchase Agreement (as defined herein) its Floating Rate Convertible Senior
Debentures due 2024 (the "Securities"). As an inducement to the Purchasers to
enter into the Purchase Agreement and in satisfaction of a condition to the
obligations of the Purchasers thereunder, the Company agrees with the Purchasers
for the benefit of Holders (as defined herein) from time to time of the
Registrable Securities (as defined herein) as follows:

         1.       Definitions.

         (a)      Capitalized terms used herein without definition shall have
the meanings ascribed to them in the Purchase Agreement. As used in this
Agreement, the following defined terms shall have the following meanings:

         "Additional Interest" has the meaning assigned thereto in Section 7(a)
hereof.

         "Affiliate" of any specified person means any other person which,
directly or indirectly, is in control of, is controlled by, or is under common
control with such specified person. For purposes of this definition, control of
a person means the power, direct or indirect, to direct or cause the direction
of the management and policies of such person whether by contract or otherwise;
and the terms "controlling" and "controlled" have meanings correlative to the
foregoing.

         "Closing Date" means the Firm Closing Date as defined in the Purchase
Agreement.

         "Commission" means the United States Securities and Exchange
Commission, or any other federal agency at the time administering the Exchange
Act or the Securities Act, whichever is the relevant statute for the particular
purpose.

         "DTC" means The Depository Trust Company.

         "Effective Time" means the time at which the Commission declares the
Shelf Registration Statement effective or at which the Shelf Registration
Statement otherwise becomes effective.

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         "Electing Holder" has the meaning assigned thereto in Section 3(a)(iv)
hereof.

         "Exchange Act" means the United States Securities Exchange Act of 1934,
as amended.

         "Holder" means any person that is the record owner of Registrable
Securities (and includes any person that has a beneficial interest in any
Registrable Security in book-entry form).

         "Indenture" means the Indenture, dated as of April 10, 1992, as amended
on October 13, 1992, between the Company and JPMorgan Chase Bank (as successor
to Chase Manhattan Bank), as amended and supplemented from time to time in
accordance with its terms and as further supplemented by a Fourth Supplemental
Indenture dated as of December 16, 2003 between the Company and JPMorgan Chase
Bank, as amended and supplemented from time to time in accordance with its
terms.

         "Managing Underwriters" means the investment banker or investment
bankers and manager or managers that shall administer an underwritten offering,
if any, conducted pursuant to Section 6 hereof.

         "NASD Rules" means the Rules of the National Association of Securities
Dealers, Inc., as amended from time to time.

         "Notice and Questionnaire" means a Selling Security holder Notice and
Questionnaire substantially in the form of Annex A to the Offering Memorandum
dated December 10, 2003 relating to the offering of the Securities and, to the
extent required, in the opinion of counsel to the Issuer, to comply with
applicable law, may include additional questions or requests for additional
information regarding Holders of Registrable Securities and the proposed
distribution by such Holders.

         The term "person" means an individual, partnership, corporation, trust
or unincorporated organization, or a government or agency or political
subdivision thereof.

         "Prospectus" means the prospectus (including, without limitation, any
preliminary prospectus, any final prospectus and any prospectus that discloses
information previously omitted from a prospectus filed as part of an effective
registration statement in reliance upon Rule 430A under the Securities Act)
included in the Shelf Registration Statement, as amended or supplemented by any
prospectus supplement with respect to the terms of the offering of any portion
of the Registrable Securities covered by the Shelf Registration Statement and by
all other amendments and supplements to such prospectus, including all material
incorporated by reference in such prospectus and all documents filed after the
date of such prospectus by the Company under the Exchange Act and incorporated
by reference therein.

         "Purchase Agreement" means the purchase agreement, dated as of December
10, 2003 between the Purchasers and the Company relating to the Securities.

         "Purchasers" means the Purchasers named in Schedule I to the Purchase
Agreement.

         "Registrable Securities" means all or any portion of the Securities
issued from time to time under the Indenture in registered form and the shares
of Stock issuable upon conversion of such Securities; provided, however, that a
security ceases to be a Registrable Security when it is no longer a Restricted
Security.

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         "Registration Default" has the meaning assigned thereto in Section 7(a)
hereof.

         "Restricted Security" means any Security or share of Stock issuable
upon conversion thereof, except any such Security or share of Stock that (i) has
been effectively registered under the Securities Act and disposed of in a manner
contemplated by the Shelf Registration Statement, (ii) has been transferred in
compliance with Rule 144 under the Securities Act (or any successor provision
thereto) or is transferable pursuant to paragraph (k) of such Rule 144 (or any
successor provision thereto) (which as of the Issue Date is two years), (iii)
has otherwise been transferred and a new Security or share of Stock not subject
to transfer restrictions under the Securities Act has been delivered by or on
behalf of the Company in accordance with Section 2.06 of the Indenture or (iv)
ceases to be outstanding (whether as a result of redemption, repurchase and
cancellation, conversion or otherwise); provided that shares of Common Stock
issuable upon conversion of Securities which Securities cease to be Restricted
Securities shall cease to be Restricted Securities at such time.

         "Rules and Regulations" means the published rules and regulations of
the Commission promulgated under the Securities Act or the Exchange Act, as in
effect at any relevant time.

         "Scheduled Window Period" means the period set forth in clause (i) in
the definition of Window Period.

         "Securities Act" means the United States Securities Act of 1933, as
amended.

         "Shelf Registration" means a registration effected pursuant to Section
2 hereof.

         "Shelf Registration Statement" means a "shelf" registration statement
filed under the Securities Act providing for the registration of, and the sale
on a continuous or delayed basis by the Holders of, all of the Registrable
Securities pursuant to Rule 415 under the Securities Act and/or any similar rule
that may be adopted by the Commission, filed by the Company pursuant to the
provisions of Section 2 of this Agreement, including the Prospectus contained
therein, any amendments and supplements to such registration statement,
including post-effective amendments, and all exhibits and all material
incorporated by reference in such registration statement.

         "Stock" means the Company's common stock, par value $0.33 1/3 per share
(and any securities into or for which such Stock has been converted or
exchanged).

         "Trust Indenture Act" means the Trust Indenture Act of 1939, as
amended, or any successor thereto, and the rules, regulations and forms
promulgated thereunder, as the same shall be further amended from time to time.

         "Window Period" means each of the following periods following the
Effective Time:

                  (i) the 20 calendar day period commencing on the Trading Day
         (as defined in the Indenture) immediately following the date the
         Company is required to file a Quarterly Report on Form 10-Q or Annual
         Report on Form 10-K under the Exchange Act, which such dates are
         anticipated to be (A) 45 days after the end of the fiscal quarters
         ended June 30, 2004 and September 30, 2004, (B) 60 days after the end
         of the fiscal years ended December 31, 2004 and December 31, 2005 and
         (C) 40 days after the end of the fiscal quarters ended March 31, 2005,
         June 30, 2005 and September 30, 2005.

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                  (ii) the period commencing on the date a notice of redemption
         is mailed to each Holder in accordance with Section 12.2 of the
         Indenture and ending on the redemption date set forth in such notice;

                  (iii) the period commencing on the date of delivery of the
         Company's notice of the occurrence of a Fundamental Change (as defined
         in the Indenture) in accordance with Article 7 of the Fourth
         Supplemental Indenture and ending on the Fundamental Change Purchase
         Date (as defined in the Indenture), unless the Company elects to pay
         all conversions of Securities during such period entirely in cash under
         the terms of the Indenture; and

                  (iv) the period commencing on the date of delivery of the
         Company's notice of any transaction specified in Section 5.01(d) of the
         Fourth Supplemental Indenture and ending on the earlier of the Business
         Day following the "ex-dividend" date (within the meaning of the
         Indenture) for such transaction or the Company's public announcement
         that such transaction will not occur, unless the Company elects to pay
         all conversions of Securities during such period entirely in cash under
         the terms of the Indenture,

in each case until the date on which no Restricted Securities are outstanding.

         The term "underwriter" means any underwriter of Registrable Securities
in connection with an offering thereof under a Shelf Registration Statement.

         (b)      Wherever there is a reference in this Agreement to a
percentage of the "principal amount" of Registrable Securities or to a
percentage of Registrable Securities, Stock shall be treated as representing the
principal amount of Securities that was surrendered for conversion or exchange
in order to receive such number of shares of Stock.

         2.       Shelf Registration.

         (a)      The Company shall, no later than 90 calendar days following
the Closing Date, file with the Commission a Shelf Registration Statement
relating to the offer and sale of the Registrable Securities by the Holders from
time to time in accordance with the methods of distribution elected by such
Holders in accordance with the terms set forth in the Notice and Questionnaire
and set forth in such Shelf Registration Statement; provided that in no event
will such method(s) of distribution take the form of an underwritten offering of
the Registrable Securities without the prior agreement of the Company and,
thereafter, shall use its reasonable efforts to cause such Shelf Registration
Statement to be declared effective under the Securities Act no later than 180
calendar days following the Closing Date; provided, however, that the Company
may, upon written notice to all Holders, postpone having the Shelf Registration
Statement declared effective for a reasonable period not to exceed 90 calendar
days if the Company possesses material non-public information, the disclosure of
which would have a material adverse effect on the Company and its subsidiaries
taken as a whole; provided, further, however, that no Holder shall be entitled
to be named as a selling securityholder in the Shelf Registration Statement or
to use the Prospectus forming a part thereof for resales of Registrable
Securities unless such Holder is an Electing Holder.

         (b)      The Company shall use its reasonable efforts:

                  (i)      to keep the Shelf Registration Statement continuously
         effective under the Securities Act during any Window Period in order to
         permit the Prospectus forming a

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         part thereof to be usable by Electing Holders; provided, however, that
         the Company need not keep such Shelf Registration Statement
         continuously effective or deliver the Prospectus forming a part thereof
         to be usable by Electing Holders during a Scheduled Window Period if:
         (A) during such Scheduled Window Period the Company is in possession of
         material nonpublic information, the disclosure of which would have a
         material adverse effect on the Company and its subsidiaries taken as a
         whole and (B) the Company provides written notice to Holders of
         Registrable Securities of its suspension of the Shelf Registration
         Statement during any such Scheduled Window Period pursuant to this
         Section 2(b)(i). If the Company suspends the use of a Shelf
         Registration Statement at any time during such Scheduled Window Period
         pursuant to this Section 2(b)(i), the Company shall cause the Shelf
         Registration Statement to be continuously effective and available for
         the sale of Registrable Securities as soon as the Company is no longer
         in possession of such material nonpublic information, for another 20
         calendar day period (such 20 day period shall be deemed for the
         purposes of this Registration Rights Agreement a new Scheduled Window
         Period). The Company shall notify holders of Registrable Securities at
         least five days in advance of the commencement of such 20 calendar day
         period.

                  (ii)     subject to Section 2(b)(i) above, after the Effective
         Time of the Shelf Registration Statement, following the request of any
         Holder of Registrable Securities that is not then an Electing Holder,
         to take any action reasonably necessary to enable such Holder to use
         the Prospectus forming a part thereof for resales of Registrable
         Securities, including, without limitation, any action necessary to
         identify such Holder as a selling securityholder in the Shelf
         Registration Statement in accordance with the procedures set forth in
         Section 3(a) hereof or any action necessary to cause the Commission, as
         promptly as practicable, to declare any post-effective amendment to the
         Shelf Registration Statement effective. Nothing in this subparagraph
         shall relieve such Holder of the obligation to return a completed and
         signed Notice and Questionnaire to the Company in accordance with
         Section 3(a)(ii) hereof.

The Company shall be deemed not to have used its reasonable efforts to keep the
Shelf Registration Statement effective during a Window Period if the Company
voluntarily takes any action that would result in Holders of Registrable
Securities covered thereby not being able to offer and sell any of such
Registrable Securities during that period, unless such action is taken pursuant
to Section 2(b)(i) or is required by applicable law and the Company thereafter
promptly complies with the requirements of paragraph 3(j) below.

         3.       Registration Procedures. In connection with the Shelf
Registration Statement, the following provisions shall apply:

         (a)(i)   Not less than 30 calendar days prior to the Effective Time
of the Shelf Registration Statement, the Company shall mail the Notice and
Questionnaire to the Holders of Registrable Securities along with notice of (A)
the fact that the Company has filed or intends to file the Shelf Registration
Statement with the Commission and (B) the deadline, as set forth in this clause
(i) for any Holder to return such Notice and Questionnaire to the Company in
order to be named as a selling securityholder in the Shelf Registration
Statement as of the Effective Time. No Holder shall be entitled to have its
Restricted Securities included in the Shelf Registration Statement pursuant to
this Agreement or to be named as a selling securityholder in the Shelf
Registration Statement as of the Effective Time, unless such Holder has returned
a completed and signed Notice and Questionnaire to the Company at least five
Business Days

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prior to the Effective Time; provided, however, that Holders of Registrable
Securities shall have at least 28 calendar days from the date on which the
Notice and Questionnaire is first mailed to such Holders to return a completed
and signed Notice and Questionnaire to the Company. Upon receipt of a written
request for additional information from the Company, each Holder who intends to
be named as a selling securityholder in the Shelf Registration Statement shall
furnish to the Company in writing, within five business days after such Holder's
receipt of such request, such additional information regarding such Holder and
the proposed distribution by such Holder of its Restricted Securities, in
connection with the Shelf Registration Statement or Prospectus included therein
and in any application to be filed with or under state securities law, to the
extent required, in the opinion of counsel to the Issuer, to comply with
applicable law. In addition, each Holder of Registrable Securities included in
the Shelf Registration Statement agrees to furnish promptly to the Issuer all
information reasonably required to be disclosed in order to make information
previously furnished to the Issuer by such Holder not materially misleading in
the opinion of counsel to the Issuer. Each Holder further agrees that it will
not use or distribute any Prospectus except during a Window Period.

                  (ii)     After the Effective Time of the Shelf Registration
         Statement, the Company shall, upon the request of any Holder of
         Registrable Securities that is not then an Electing Holder, promptly
         send a Notice and Questionnaire to such Holder. The Company shall not
         be required to take any action to name such Holder as a selling
         securityholder in the Shelf Registration Statement or to enable such
         Holder to use the Prospectus forming a part thereof for resales of
         Registrable Securities until such Holder has returned a completed and
         signed Notice and Questionnaire to the Company.

                  (iii)    Subject to Section 2(b)(i), on the fifth Business Day
         prior to the commencement of any Scheduled Window Period, the Company
         shall file an amendment to the Shelf Registration Statement or
         supplement to the related Prospectus with respect to all completed
         Notice and Questionnaires received from Electing Holders on or prior to
         the tenth Business Day prior to such Scheduled Window Period. In
         respect of any Window Period other than a Scheduled Window Period, on
         the date of commencement of such Window Period, the Company shall make
         a public announcement of such Window Period by a release to Reuters
         Economic Services and Bloomberg Business News, and on the fifth
         Business Day following the announcement of such Window Period, shall
         file an amendment to the Shelf Registration Statement or supplement to
         the related Prospectus with respect to all completed Notice and
         Questionnaires received from Electing Holders prior to such fifth
         Business Day in order to name such Electing Holders as selling
         securityholders under the Shelf Registration Statement.

                  (iv)     The term "Electing Holder" shall mean any Holder of
         Registrable Securities that has returned a completed and signed Notice
         and Questionnaire to the Company in accordance with Section 3(a)(i),
         3(a)(ii) or 3(a)(iii) hereof.

         (b)      The Company shall furnish to each Electing Holder, three
business days prior to the Effective Time, a copy of the Shelf Registration
Statement initially filed with the Commission (except to the extent that such
documents are available by EDGAR), and shall furnish to such Holders, three
business days prior to the filing thereof with the Commission, copies of each
amendment thereto and each amendment or supplement, if any, to the Prospectus
included therein (other than amendments or supplements adding other Holders as
Electing Holders or otherwise affecting other Holders only), and shall use its
reasonable efforts to reflect in each

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such document, or in a subsequent filing, at the Effective Time or when so filed
with the Commission, as the case may be, such comments as such Holders and their
respective counsel reasonably may propose within two business days of the
delivery of such copies to such Holders.

         (c)      The Company shall promptly take such action as may be
necessary so that (i) each of the Shelf Registration Statement and any amendment
thereto and the Prospectus forming a part thereof and any amendment or
supplement thereto (and each report or other document incorporated therein by
reference in each case) complies in all material respects with the Securities
Act and the Exchange Act and the respective rules and regulations thereunder,
(ii) each of the Shelf Registration Statement and any amendment thereto does
not, when it becomes effective, contain an untrue statement of a material fact
or omit to state a material fact required to be stated therein or necessary to
make the statements therein not misleading and (iii) each of the Prospectus
forming a part of the Shelf Registration Statement, and any amendment or
supplement to such Prospectus, does not at any time during any Window Period
include an untrue statement of a material fact or omit to state a material fact
necessary in order to make the statements therein, in the light of the
circumstances under which they were made, not misleading.

         (d)      The Company shall promptly advise each Electing Holder, and
shall confirm such advice in writing if so requested by any such Electing
Holder:

                  (i)      when a Shelf Registration Statement and any amendment
         thereto has been filed with the Commission and when a Shelf
         Registration Statement or any post-effective amendment thereto has
         become effective, in each case by making a public announcement thereof
         by release made to Reuters Economic Services and Bloomberg Business
         News or publishing the information on our web site or through such
         other public medium as we may use at that time;

                  (ii)     of any request by the Commission for amendments or
         supplements to the Shelf Registration Statement or the Prospectus
         included therein or for additional information relating thereto;

                  (iii)    of the issuance by the Commission of any stop order
         suspending the effectiveness of the Shelf Registration Statement or the
         initiation of any proceedings for such purpose;

                  (iv)     of the receipt by the Company of any notification
         with respect to the suspension of the qualification of the securities
         included in the Shelf Registration Statement for sale in any
         jurisdiction or the initiation of any proceeding for such purpose; and

                  (v)      of the occurrence of any event or the existence of
         any state of facts that requires the making of any changes in the Shelf
         Registration Statement or the Prospectus included therein so that, as
         of such date (but only during any Window Period), such Shelf
         Registration Statement and Prospectus do not contain an untrue
         statement of a material fact and do not omit to state a material fact
         required to be stated therein or necessary to make the statements
         therein (in the case of the Prospectus, in light of the circumstances
         under which they were made) not misleading (which advice shall be
         accompanied by an instruction to such Holders to suspend the use of the
         Prospectus until the requisite changes have been made).

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         (e)      The Company shall use its reasonable efforts to prevent the
issuance, and if issued to obtain the withdrawal at the earliest possible time,
of any stop order suspending the effectiveness of the Shelf Registration
Statement.

         (f)      The Company shall furnish to each Electing Holder, without
charge, at least one copy of the Shelf Registration Statement and all
post-effective amendments thereto, including financial statements and schedules;
provided that to the extent such document is available by EDGAR the Company
shall be deemed to have complied with this subsection.

         (g)      The Company shall, during any Window Period, deliver to each
Electing Holder, without charge, as many copies of the Prospectus (including
each preliminary Prospectus) included in the Shelf Registration Statement and
any amendment or supplement thereto (other than amendments or supplements adding
other Holders as Electing Holders or otherwise affecting other Holders only) as
such Electing Holder may reasonably request; and the Company consents (except
during the continuance of any event or the existence of any state of facts
described in Section 3(d)(v) above) to the use of the Prospectus and any
amendment or supplement thereto by each of the Electing Holders in connection
with the offering and sale of the Registrable Securities covered by the
Prospectus and any amendment or supplement thereto during any Window Period.

         (h)      Prior to any offering of Registrable Securities pursuant to
the Shelf Registration Statement, the Company shall (i) register or qualify or
cooperate with the Electing Holders and their respective counsel in connection
with the registration or qualification of such Registrable Securities for offer
and sale under the securities or "blue sky" laws of such jurisdictions within
the United States as any Electing Holder may reasonably request, (ii) keep such
registrations or qualifications in effect and comply with such laws so as to
permit the continuance of offers and sales in such jurisdictions (during any
Window Period) for so long as may be necessary to enable any Electing Holder or
underwriter, if any, to complete its distribution of Registrable Securities
pursuant to the Shelf Registration Statement, and (iii) take any and all other
actions necessary or advisable to enable the disposition in such jurisdictions
of such Registrable Securities (during any Window Period); provided, however,
that in no event shall the Company be obligated to (A) register or qualify as a
foreign corporation or as a dealer in securities in any jurisdiction where it
would not otherwise be required to so qualify but for this Section 3(h) or (B)
file any general consent to service of process in any jurisdiction where it is
not as of the date hereof so subject.

         (i)      Unless any Registrable Securities shall be in book-entry only
form, the Company shall cooperate with the Electing Holders to facilitate the
timely preparation and delivery of certificates representing Registrable
Securities to be sold pursuant to the Shelf Registration Statement, which
certificates, if so required by any securities exchange upon which any
Registrable Securities are listed, shall be penned, lithographed or engraved, or
produced by any combination of such methods, on steel engraved borders, and
which certificates shall be free of any restrictive legends and in such
permitted denominations and registered in such names as Electing Holders may
request in connection with the sale of Registrable Securities pursuant to the
Shelf Registration Statement.

         (j)      Upon the occurrence of any event or the existence of any state
of facts contemplated by paragraph 3(d)(v) above, the Company shall promptly
prepare a post-effective amendment to any Shelf Registration Statement or an
amendment or supplement to the related Prospectus or file any other required
document so that, as thereafter delivered to purchasers of

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the Registrable Securities included therein, the Prospectus will not include an
untrue statement of a material fact or omit to state any material fact required
to be stated therein or necessary to make the statements therein, in light of
the circumstances under which they were made, not misleading. If the Company
notifies the Electing Holders of the occurrence of any event or the existence of
any state of facts contemplated by paragraph 3(d)(v) above, the Electing Holder
shall suspend use of the Prospectus until (i) such Electing Holder's receipt of
the copies of the amended or supplemented prospectus or (ii) such Electing
Holder is advised in writing that the Prospectus may be used, and has received
copies of any additional or supplemental filings that are incorporated by
reference, in the Prospectus.

         (k)      Not later than the Effective Time of the Shelf Registration
Statement, the Company shall provide a CUSIP number for the Registrable
Securities sold under the Shelf Registration Statement that are debt securities.

         (l)      The Company shall use its reasonable efforts to comply with
all applicable Rules and Regulations, and to make generally available to its
securityholders as soon as practicable, after (i) the effective date (as defined
in Rule 158(c) under the Securities Act) of the Shelf Registration Statement,
(ii) the effective date of each post-effective amendment to the Shelf
Registration Statement (other than post-effective amendments adding Elected
Holders or otherwise affecting other Elected Holders) and (iii) the date of each
filing by the Company with the Commission of an Annual Report on Form 10-K that
is incorporated by reference in the Shelf Registration Statement, an earnings
statement of the Company and its subsidiaries (audited to the extent reasonably
available) complying with Section 11(a) of the Securities Act and the rules and
regulations of the Commission thereunder (including, at the option of the
Company, Rule 158).

         (m)      In the event of an underwritten offering conducted pursuant to
Section 6 hereof, the Company shall, if requested, promptly include or
incorporate in a Prospectus supplement or post-effective amendment to the Shelf
Registration Statement such information as the Managing Underwriters reasonably
agree should be included therein and to which the Company does not reasonably
object and shall make all required filings of such Prospectus supplement or
post-effective amendment as soon as practicable after it is notified of the
matters to be included or incorporated in such Prospectus supplement or
post-effective amendment.

         (n)      The Company shall enter into such customary agreements
(including an underwriting agreement in customary form in the event of an
underwritten offering conducted pursuant to Section 6 hereof) and take all other
appropriate action in order to expedite and facilitate the registration and
disposition of the Registrable Securities, and in connection therewith, if an
underwriting agreement is entered into, cause the same to contain
indemnification provisions and procedures substantially identical to those set
forth the Purchase Agreement.

         (o)      The Company shall:

                  (i)(A)   subject to the execution of a confidentiality
         agreement reasonably acceptable to the Company, make reasonably
         available for inspection, during reasonable business hours, by any
         underwriter participating in any disposition pursuant to the Shelf
         Registration Statement, and any attorney, accountant or other agent
         retained by any such underwriter all relevant financial and other
         records, pertinent corporate documents and properties of the Company
         and its subsidiaries, and (B) cause

                                       9
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         the Company's officers, directors and employees to supply all
         information reasonably requested by any such underwriter, attorney,
         accountant or agent in connection with the Shelf Registration
         Statement, in each case, as shall be reasonably necessary to enable
         them to exercise any applicable due diligence defenses; provided,
         however, that all records, information and documents shall be kept
         confidential by any such underwriter, attorney, accountant or agent in
         accordance with such confidentiality agreement, unless such disclosure
         is made as reasonably necessary to establish any due diligence defenses
         in connection with a court proceeding or required by law, or such
         records, information or documents become available to the public
         generally or through a third party without an accompanying obligation
         of confidentiality;

                  (ii)     in connection with any underwritten offering
         conducted pursuant to Section 6 hereof, make such representations and
         warranties to the Electing Holders participating in such underwritten
         offering and to the Managing Underwriters, in form, substance and scope
         as are customarily made by the Company to underwriters in primary
         underwritten offerings of convertible debt securities and covering
         matters set forth in the Purchase Agreement, it being understood and
         agreed that representations and warranties comparable to those
         contemplated by the Purchase Agreement, as amended to reflect a
         registered offering, shall be satisfactory;

                  (iii)    in connection with any underwritten offering
         conducted pursuant to Section 6 hereof, obtain opinions of counsel to
         the Company (which counsel and opinions in form, scope and substance
         shall be reasonably satisfactory to the Managing Underwriters, it being
         understood and agreed that opinions comparable to those contemplated by
         the Purchase Agreement and delivered pursuant to the Purchase
         Agreement, as amended to reflect a registered offering, shall be
         satisfactory) addressed to each Electing Holder participating in such
         underwritten offering and the underwriters, covering such matters as
         are customarily covered in opinions requested in primary underwritten
         offerings by the Company of convertible debt securities (it being
         agreed that the matters to be covered by such opinions shall include,
         in form, scope and substance comparable to the opinions contemplated by
         the Purchase Agreement and delivered pursuant to the Purchase
         Agreement, as amended to reflect a registered offering, as of the date
         of the opinion and as of the Effective Time of the Shelf Registration
         Statement or most recent post-effective amendment thereto, as the case
         may be, the absence from the Shelf Registration Statement and the
         Prospectus, including the documents incorporated by reference therein,
         of an untrue statement of a material fact or the omission of a material
         fact required to be stated therein or necessary to make the statements
         therein not misleading);

                  (iv)     in connection with any underwritten offering
         conducted pursuant to Section 6 hereof, obtain "cold comfort" letters
         and updates thereof from the independent public accountants of the
         Company (and, if necessary, from the independent public accountants of
         any subsidiary of the Company or of any business acquired by the
         Company for which financial statements and financial data are, or are
         required to be, included in the Shelf Registration Statement),
         addressed to each Electing Holder participating in such underwritten
         offering (if such Electing Holder has provided such letter,
         representations or documentation, if any, required for such "cold
         comfort" letter to be so addressed) and the underwriters, in customary
         form and covering matters of the type customarily covered in "cold
         comfort" letters in connection with primary underwritten offerings by
         the Company of convertible debt securities (it being understood and
         agreed

                                       10
<PAGE>

         that "cold comfort" letters comparable to those contemplated by the
         Purchase Agreement and delivered pursuant to the Purchase Agreement, as
         amended to reflect a registered offering, shall be satisfactory);

                  (v)      in connection with any underwritten offering
         conducted pursuant to Section 6 hereof, deliver such documents and
         certificates as may be reasonably requested by any Electing Holders
         participating in such underwritten offering and the Managing
         Underwriters, if any, including, without limitation, certificates to
         evidence compliance with Section 3(j) hereof and with any conditions
         contained in the underwriting agreement or other agreements entered
         into by the Company, which certificates in each case shall be
         comparable to those required by the terms and conditions of the
         Purchase Agreement and delivered pursuant to the Purchase Agreement, as
         amended to reflect a registered offering.

         (p)      The Company will use its reasonable efforts to cause the Stock
issuable upon conversion of the Securities to be listed on the New York Stock
Exchange or other stock exchange or trading system on which the Stock primarily
trades on or prior to the Effective Time of the Shelf Registration Statement
hereunder.

         (q)      In the event that any broker-dealer registered under the
Exchange Act shall be an "affiliate" (as defined in Rule 2720(b)(1) of the NASD
Rules (or any successor provision thereto)) of the Company or has a "conflict of
interest" (as defined in Rule 2720(b)(7) of the NASD Rules (or any successor
provision thereto)) and such broker-dealer shall underwrite, participate as a
member of an underwriting syndicate or selling group or assist in the
distribution of any Registrable Securities covered by the Shelf Registration
Statement, whether as a Holder of such Registrable Securities or as an
underwriter, a placement or sales agent or a broker or dealer in respect
thereof, or otherwise, the Company shall assist such broker-dealer in complying
with the requirements of the NASD Rules, including, without limitation, by (A)
engaging a "qualified independent underwriter" (as defined in Rule 2720(b)(15)
of the NASD Rules (or any successor provision thereto)) to participate in the
preparation of the Shelf Registration Statement, to exercise usual standards of
due diligence in respect thereto and to recommend the public offering price of
such Registrable Securities, (B) indemnifying such qualified independent
underwriter to the extent of the indemnification of underwriters provided in the
Purchase Agreement, and (C) providing such information to such broker-dealer as
may be required in order for such broker-dealer to comply with the requirements
of the NASD Rules.

         (r)      The Company shall use its reasonable efforts to take all other
steps necessary to effect the registration of the Registrable Securities covered
by the Shelf Registration Statement contemplated hereby.

         4.       Registration Expenses. Except as otherwise provided in Section
3, the Company shall bear all fees and expenses incurred in connection with the
performance of its obligations under Sections 2, 3 and 6 hereof. Each Electing
Holder shall pay all underwriting discounts and commissions and transfer taxes,
if any, relating to the sale or disposition of such Electing Holder's
Registrable Securities pursuant to the Shelf Registration Statement, and the
fees and disbursements of its counsel and other representatives.

         5.       Indemnification and Contribution.

         (a)      Indemnification by the Company. Upon the registration of the
Registrable Securities pursuant to Section 2 hereof, the Company shall indemnify
and hold harmless each

                                       11
<PAGE>

Electing Holder and each underwriter, selling agent or other securities
professional, if any, which facilitates the disposition of Registrable
Securities, and each person, if any, who controls such Electing Holder,
underwriter, selling agent or other securities professional within the meaning
of either Section 15 of the Securities Act or Section 20 of the Exchange Act
(each such person being sometimes referred to as an "Indemnified Person") from
and against any and all losses, claims, damages and liabilities (including,
without limitation, any legal or other expenses reasonably incurred by any
Indemnified Person in connection with defending or investigating any such action
or claim) caused by any untrue statement or alleged untrue statement of a
material fact contained in any Shelf Registration Statement under which
Registrable Securities are to be registered under the Securities Act or any
Prospectus contained therein or furnished by the Company to any Indemnified
Person (as amended or supplemented, if the Company shall have furnished any
amendments or supplements thereto), or caused by any omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, except insofar as such
losses, claims, damages or liabilities are caused by any such untrue statement
or omission or alleged untrue statement or omission based upon and in conformity
with information relating to any Indemnified Person furnished to the Company in
writing by such Indemnified Person expressly for use therein; provided, however,
that the foregoing indemnity agreement with respect to any Shelf Registration
Statement under which Registrable Securities are to be registered under the
Securities Act or any Prospectus contained therein or furnished by the Company
to any Indemnified Person shall not inure to the benefit of any Indemnified
Person from whom the person asserting any such losses, claims, damages or
liabilities purchased Registrable Securities, or any person controlling such
Indemnified Person, if a copy of the Shelf Registration Statement under which
Registrable Securities are to be registered under the Securities Act or any
Prospectus contained therein or furnished by the Company to any Indemnified
Person (as then amended or supplemented, if the Company shall have furnished any
amendments or supplements thereto) was not sent or given by or on behalf of such
Indemnified Person to such person, if required by law so to have been delivered,
at or prior to the written confirmation of the disposition of the Registrable
Securities to such person, and if the Shelf Registration Statement under which
Registrable Securities are to be registered under the Securities Act or any
Prospectus contained therein or furnished by the Company to any Indemnified
Person (as so amended or supplemented) would have cured the defect giving rise
to such losses claims, damages or liabilities.

         (b)      Indemnification by the Electing Holders and any Agents and
Underwriters. Each Electing Holder agrees, as a consequence of the inclusion of
any of such Electing Holder's Registrable Securities in such Shelf Registration
Statement, and each underwriter, selling agent or other securities professional,
if any, which facilitates the disposition of Registrable Securities shall agree,
as a consequence of facilitating such disposition of Registrable Securities,
severally and not jointly, to indemnify and hold harmless the Company, its
directors and officers and each person, if any, who controls the Company within
the meaning of either Section 15 of the Securities Act or Section 20 of the
Exchange Act, to the same extent as the foregoing indemnity contained in
subsection (a) above from the Company to such Electing Holder, underwriter,
selling agent or other securities professional, but only with reference to
information relating to such Electing Holder, underwriter, selling agent or
other securities professional furnished to the Company by such Electing Holder,
underwriter, selling agent or other securities professional in writing expressly
for use in the Registration Statement under which Registrable Securities

                                       12
<PAGE>

are to be registered under the Securities Act or any Prospectus contained
therein or furnished by the Company to any Electing Holder, underwriter, selling
agent or other securities professional or any amendments or supplements thereto.

         (c)      Notices of Claims, Etc. In case any proceeding (including any
governmental investigation) shall be instituted involving any person in respect
of which indemnity may be sought pursuant to either subsection (a) or (b) above,
such person (the "indemnified party") shall promptly notify the person against
whom such indemnity may be sought (the "indemnifying party") in writing;
provided that the failure to notify the indemnifying party shall not relieve it
from any liability that it may have under this Section 5 except to the extent
that it has been materially prejudiced (through the forfeiture of substantive
rights or defenses) by such failure; provided, further, that the failure to
notify the indemnifying party shall not relieve it from any liability that it
may have to any indemnified party otherwise than under this Section 5. The
indemnifying party, upon request of the indemnified party, shall retain counsel
reasonably satisfactory to the indemnified party to represent the indemnified
party and any others the indemnifying party may designate in such proceeding and
shall pay the fees and disbursements of such counsel related to such proceeding.
In any such proceeding, any indemnified party shall have the right to retain its
own counsel, but the fees and expenses of such counsel shall be at the expense
of such indemnified party unless (i) the indemnifying party and the indemnified
party shall have mutually agreed to the retention of such counsel, (ii) the
named parties to any such proceeding (including any impleaded parties) include
both the indemnifying party and the indemnified party and representation of both
parties by the same counsel would be inappropriate due to actual or potential
conflicting interests between them or (iii) the indemnified party shall have
reasonably concluded that there may be legal defenses available to it that are
different from or in addition to those available to the indemnifying party. It
is understood that the indemnifying party shall not, in respect of the legal
expenses of any indemnified party in connection with any proceeding or related
proceedings in the same jurisdiction, be liable for the fees and expenses of
more than one separate firm (in addition to any applicable local counsel) for
all such indemnified parties and that all such fees and expenses shall be
reimbursed as they are incurred. Such firm shall be designated in writing by the
Indemnified Person, in the case of parties indemnified pursuant to paragraph (a)
above, and by the Company, in the case of parties indemnified pursuant to
paragraph (b) above. The indemnifying party shall not be liable for any
settlement of any proceeding effected without its written consent, but if
settled with such consent or if there be a final judgment for the plaintiff, the
indemnifying party agrees to indemnify the indemnified party from and against
any loss or liability by reason of such settlement or judgment. No indemnifying
party shall, without the prior written consent of the indemnified party, effect
any settlement of any pending or threatened proceeding in respect of which any
indemnified party is or could have been a party and indemnity could have been
sought hereunder by such indemnified party, unless such settlement includes an
unconditional release of such indemnified party from all liability on claims
that are the subject matter of such proceeding and does not include any
statement as to or any admission of fault, culpability or a failure to act by or
on behalf of any indemnified party.

         (d)      Contribution. If the indemnification provided for in this
Section 5 is unavailable to hold harmless an indemnified party under subsection
(a) or (b) above in respect of any losses, claims, damages or liabilities (or
actions in respect thereof) referred to therein (other than because such
indemnification by its terms does not apply), then each indemnifying party shall
contribute to the amount paid or payable by such indemnified party as a result
of such losses, claims, damages or liabilities (or actions in respect thereof)
in such proportion as is appropriate to reflect the relative fault of the
indemnifying party and the indemnified party in connection with

                                       13
<PAGE>

the statements or omissions which resulted in such losses, claims, damages or
liabilities (or actions in respect thereof), as well as any other relevant
equitable considerations. The relative fault of such indemnifying party and
indemnified party shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or omission or
alleged omission to state a material fact relates to information supplied by
such indemnifying party or by such indemnified party, and the parties' relative
intent, knowledge, access to information and opportunity to correct or prevent
such statement or omission. The parties hereto agree that it would not be just
and equitable if contribution pursuant to this Section 5(d) were determined by
pro rata allocation (even if the Electing Holders or any underwriters, selling
agents or other securities professionals or all of them were treated as one
entity for such purpose) or by any other method of allocation which does not
take account of the equitable considerations referred to in this Section 5(d).
The amount paid or payable by an indemnified party as a result of the losses,
claims, damages or liabilities (or actions in respect thereof) referred to above
shall be deemed to include any legal or other fees or expenses reasonably
incurred by such indemnified party in connection with investigating or defending
any such action or claim. No person guilty of fraudulent misrepresentation
(within the meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from any person who was not guilty of such fraudulent
misrepresentation. The obligations of the Electing Holders and any underwriters,
selling agents or other securities professionals in this Section 5(d) to
contribute shall be several in proportion to the percentage of principal amount
of Registrable Securities registered or underwritten, as the case may be, by
them and not joint.

         (e)      Notwithstanding any other provision of this Section 5, in no
event will any (i) Electing Holder be required to undertake liability to any
person under this Section 5 for any amounts in excess of the dollar amount of
the proceeds to be received by such Holder from the sale of such Holder's
Registrable Securities (after deducting any fees, discounts and commissions
applicable thereto) pursuant to any Shelf Registration Statement under which
such Registrable Securities are to be registered under the Securities Act and
(ii) underwriter, selling agent or other securities professional be required to
undertake liability to any person hereunder for any amounts in excess of the
total price at which the Registrable Securities underwritten by it were offered
to the public.

         (f)      The obligations of the Company under this Section 5 shall be
in addition to any liability which the Company may otherwise have to any
Indemnified Person and the obligations of any Indemnified Person under this
Section 5 shall be in addition to any liability which such Indemnified Person
may otherwise have to the Company. The remedies provided in this Section 5 are
not exclusive and shall not limit any rights or remedies which may otherwise be
available to an indemnified party at law or in equity. The obligations of the
Company under this Section 5 shall extend, upon the same terms and conditions,
to each person, if any, who controls any Indemnified Person within the meaning
of the Securities Act; and the obligations of the Indemnified Persons under this
Section 5 shall extend, upon the same terms and conditions, to each officer and
director of the Company and to each person, if any, who controls the Company
within the meaning of the Securities Act.

         6.       Underwritten Offering. Any Holder of Registrable Securities
who desires to do so may sell Registrable Securities (in whole or in part) in an
underwritten offering; provided that (i) the Electing Holders of at least
33-1/3% in aggregate principal amount of the Registrable Securities then covered
by the Shelf Registration Statement shall request such an offering and (ii) at
least such aggregate principal amount of such Registrable Securities shall be
included in such offering; and provided further that no underwritten offering
may be conducted without the

                                       14
<PAGE>

prior agreement of the Company. Upon receipt of such a request and consent by
the Company to such request, the Company shall provide all Holders of
Registrable Securities written notice of the request, which notice shall inform
such Holders that they have the opportunity to participate in the offering. In
any such underwritten offering, the investment banker or bankers and manager or
managers that will administer the offering will be selected by, and the
underwriting arrangements with respect thereto (including the size of the
offering) will be approved by, the holders of a majority of the Registrable
Securities to be included in such offering; provided, however, that such
investment bankers and managers and underwriting arrangements must be reasonably
satisfactory to the Company. No Holder may participate in any underwritten
offering contemplated hereby unless (a) such Holder agrees to sell such Holder's
Registrable Securities to be included in the underwritten offering in accordance
with any approved underwriting arrangements, (b) such Holder completes and
executes all reasonable questionnaires, powers of attorney, indemnities,
underwriting agreements, lock-up letters and other documents required under the
terms of such approved underwriting arrangements, and (c) if such Holder is not
then an Electing Holder, such Holder returns a completed and signed Notice and
Questionnaire to the Company in accordance with Section 3(a)(ii) hereof within a
reasonable amount of time before such underwritten offering. The Holders
participating in any underwritten offering shall be responsible for any
underwriting discounts and commissions and fees and, subject to Section 4
hereof, expenses of their own counsel. The Company shall pay all expenses
customarily borne by issuers in an underwritten offering, including but not
limited to filing fees, the fees and disbursements of its counsel and
independent public accountants and any printing expenses incurred in connection
with such underwritten offering. Notwithstanding the foregoing or the provisions
of Section 3(n) hereof, upon receipt of a request from the Managing Underwriter
or a representative of holders of a majority of the Registrable Securities to be
included in an underwritten offering to prepare and file an amendment or
supplement to the Shelf Registration Statement and Prospectus in connection with
an underwritten offering, the Company may delay the filing of any such amendment
or supplement for up to 90 days if the Board of Directors, Chief Executive
Officer or Chief Financial Officer of the Company shall have determined in good
faith that the Company has a bona fide business reason for such delay.

         7.       Additional Interest.

         (a)      The following shall each constitute a "Registration Default":

                  (i)      on or prior to the 90th day following the Closing
         Date, a Shelf Registration Statement has not been filed with the
         Commission,

                  (ii)     on or prior to the 180th day following the Closing
         Date, such Shelf Registration Statement is not declared effective by
         the Commission, subject to any postponement by the Company in
         accordance with the proviso in Sections 2(a) hereof,

                  (iii)    at any time during a Window Period, the Shelf
         Registration Statement or Prospectus thereunder ceases to be effective
         or fails to be available, subject to Section 2(b)(i); provided,
         however, that a Registration Default shall be deemed to have occurred
         if the Company shall not have designated a new Scheduled Window Period
         pursuant to Section 2(b)(i) on or prior to the next Scheduled Window
         Period, such default to be deemed to occur on the commencement of such
         next Scheduled Window Period; or

                                       15
<PAGE>

                  (iv)     the Company fails to perform any of its obligations
         under Section 3(a) to file any amendment or supplement to the Shelf
         Registration Statement and related Prospectus by the date therein
         prescribed.

         (b)      Upon the occurrence and during the continuation of a
Registration Default, the Company shall be required to pay additional interest
on the Securities ("Additional Interest") from and including the day following
such Registration Default until (i) the Shelf Registration Statement is filed
(in the case of a Registration Default occurring under clause (a)(i) above),
(ii) the Shelf Registration Statement is subsequently declared effective (in the
case of a Registration Default occurring under clause (a)(ii) above), (iii) the
date the Shelf Registration Statement subsequently becomes effective or becomes
useable (in the case of a Registration Default occurring under clause (a)(iii)
above) and (iv) the date the Company cures any failure to perform its
obligations under Section 3(a) (in the case of a Registration Default occurring
under clauses (a)(iv) above). Additional Interest shall accrue at a rate per
annum equal to an additional one-quarter of one percent (0.25%) of the principal
amount of Securities to and including the 90th day following such Registration
Default, and one-half of one percent (0.50%) thereof from and after the 91st day
following such Registration Default; provided that in all events such Additional
Interest shall cease to accrue after such Securities are no longer Restricted
Securities.

         (c)      Any amounts to be paid as Additional Interest pursuant to
paragraph (b) of this Section 7 shall be paid in cash semi-annually in arrears,
with the first semi-annual payment due on the first Interest Payment Date (as
defined in the Indenture), as applicable, following the date of such
Registration Default. Such Additional Interest will accrue at the rates set
forth in paragraph (b) of this Section 7 on the principal amount of the
Securities.

         (d)      Except as provided in Section 8(b) hereof, the Additional
Interest as set forth in this Section 7 shall be the exclusive monetary remedy
available to the Holders of Registrable Securities for such Registration
Default. In no event shall the Company be required to pay Additional Interest in
excess of the applicable maximum amount of one-half of one percent (0.50%) set
forth above, regardless of whether one or multiple Registration Defaults exist.

         8.       Miscellaneous.

         (a)      Other Registration Rights. The Company may grant registration
rights that would permit any person that is a third party the right to
piggy-back on any Shelf Registration Statement, provided that if the Managing
Underwriter of any underwritten offering conducted pursuant to Section 6 hereof
notifies the Company and the Electing Holders that the total amount of
securities which the Electing Holders and the holders of such piggy-back rights
intend to include in any Shelf Registration Statement is so large as to
materially threaten the success of such offering (including the price at which
such securities can be sold), then the amount, number or kind of securities to
be offered for the account of holders of such piggy-back rights will be reduced
to the extent necessary to reduce the total amount of securities to be included
in such offering to the amount, number and kind recommended by the Managing
Underwriter prior to any reduction in the amount of Registrable Securities to be
included in such Shelf Registration Statement.

         (b)      Specific Performance. The parties hereto acknowledge that
there would be no adequate remedy at law if the Company fails to perform any of
its obligations hereunder and that the Purchasers and the Holders from time to
time may be irreparably harmed by any such

                                       16
<PAGE>

failure, and accordingly agree that the Purchasers and such Holders, in addition
to any other remedy to which they may be entitled at law or in equity and
without limiting the remedies available to the Electing Holders under Section 7
hereof, shall be entitled to compel specific performance of the obligations of
the Company under this Agreement in accordance with the terms and conditions of
this Agreement, in any court of the United States or any State thereof having
jurisdiction.

         (c)      Amendments and Waivers. This Agreement, including this Section
8(c), may be amended, and waivers or consents to departures from the provisions
hereof may be given, only by a written instrument duly executed by the Company
and the holders of a majority in aggregate principal amount of Registrable
Securities then outstanding; provided, however, that no change to the timing or
amount of Additional Interest payable to any holder of Registrable Securities
may be made without the consent of such holders. Each Holder of Registrable
Securities outstanding at the time of any such amendment, waiver or consent or
thereafter shall be bound by any amendment, waiver or consent effected pursuant
to this Section 8(c), whether or not any notice, writing or marking indicating
such amendment, waiver or consent appears on the Registrable Securities or is
delivered to such Holder. Notwithstanding the foregoing, a waiver or consent to
depart from the provisions hereof with respect to a matter that relates
exclusively to the rights of Holders of Registrable Securities whose securities
are being sold pursuant to a Shelf Registration Statement and that does not
directly or indirectly affect the rights of other Holders of Registrable
Securities being sold by such Holders pursuant to such Shelf Registration
Statement provided that the provisions of this sentence may not be amended,
modified or supplemented except in accordance with the provisions of the
immediately preceding sentence.

         (d)      Notices. All notices and other communications provided for or
permitted hereunder shall be given as provided in the Indenture. A document,
notice or advice shall be deemed to have been furnished or mailed to the Holders
of Restricted Securities if it is provided to the registered holders of the
Restricted Securities.

         (e)      Parties in Interest. The parties to this Agreement intend that
all Holders of Registrable Securities shall be entitled to receive the benefits
of this Agreement and that any Electing Holder shall be bound by the terms and
provisions of this Agreement by reason of such election with respect to the
Registrable Securities which are included in a Shelf Registration Statement. All
the terms and provisions of this Agreement shall be binding upon, shall inure to
the benefit of and shall be enforceable by the respective successors and assigns
of the parties hereto and any Holder from time to time of the Registrable
Securities to the aforesaid extent; provided that nothing herein shall be deemed
to permit any assignment, transfer or other disposition of Registrable
Securities in violation of the terms of the Purchase Agreement or Indenture. In
the event that any transferee of any Holder of Registrable Securities shall
acquire Registrable Securities, in any manner, whether by gift, bequest,
purchase, operation of law or otherwise, such transferee shall, without any
further writing or action of any kind, be entitled to receive the benefits of
and, if an Electing Holder, be conclusively deemed to have agreed to be bound by
and to perform all of the terms and provisions of this Agreement to the
aforesaid extent (including providing to the Company all information required,
including updates to its Notice and Questionnaire, to the extent required, in
the opinion of counsel to the Issuer, to comply with applicable law).

         (f)      Counterparts. This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be

                                       17
<PAGE>

deemed to be an original and all of which taken together shall constitute one
and the same agreement.

         (g)      Headings. The headings in this Agreement are for convenience
of reference only and shall not limit or otherwise affect the meaning hereof.

         (h)      GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

         (i)      Severability. In the event that any one or more of the
provisions contained herein, or the application thereof in any circumstances, is
held invalid, illegal or unenforceable in any respect for any reason, the
validity, legality and enforceability of any such provision in every other
respect and of the remaining provisions hereof shall not be in any way impaired
or affected thereby, it being intended that all of the rights and privileges of
the parties hereto shall be enforceable to the fullest extent permitted by law.

         (j)      Survival. The respective indemnities, agreements,
representations, warranties and other provisions set forth in this Agreement or
made pursuant hereto shall remain in full force and effect, regardless of any
investigation (or any statement as to the results thereof) made by or on behalf
of any Electing Holder, any director, officer or partner of such Holder, any
agent or underwriter, any director, officer or partner of such agent or
underwriter, or any controlling person of any of the foregoing, and shall
survive the transfer and registration of the Registrable Securities of such
Holder.

                                       18
<PAGE>

         Please confirm that the foregoing correctly sets forth the agreement
between the Company and you.

                                            Very truly yours,

                                            Wyeth

                                            By:   /s/ Jack M. O'Connor
                                                  ---------------------------
                                                  Name:   Jack M. O'Connor
                                                  Title:  Vice President and
                                                          Treasurer

Accepted as of the date hereof:

Citigroup Global Markets Inc.

By:   /s/ A. Scott Daniel
      --------------------------------
      Name:   A. Scott Daniel
      Title:  Director

J.P. Morgan Securities Inc.

By:  /s/ Paul O'Hern
     ---------------------------------
     Name:   Paul O'Hern
     Title:  Vice President

         On behalf of each of the Purchasers

                                       19