Execution Copy


                          REGISTRATION RIGHTS AGREEMENT


                     THIS REGISTRATION RIGHTS AGREEMENT (the "Agreement"),
dated as of December 10, 1998 by and among SEPRACOR INC., a Delaware
corporation (the "Company") and MORGAN STANLEY & CO. INCORPORATED and
SALOMON SMITH BARNEY INC. (the "Initial Purchasers") pursuant to the Purchase
Agreement, dated as of December 10, 1998 (the "Purchase Agreement"), between the
Company and the Initial Purchasers. In order to induce the Initial Purchasers to
enter into the Purchase Agreement, the Company has agreed to provide the
registration rights set forth in this Agreement. The execution of this Agreement
is a condition to the closing under the Purchase Agreement.

                     The Company agrees with the Initial Purchasers, (i) for
their benefit as Initial Purchasers and (ii) for the benefit of the holders from
time to time of the Debentures (including the Initial Purchasers) and the
holders from time to time of the Common Stock issued upon conversion of the
Debentures (each of the foregoing a "Holder" and together the "Holders"), as
follows:

     1. Definitions. Capitalized terms used herein without definition shall have
their respective meanings set forth in the Purchase Agreement. As used in this
Agreement, the following terms have the following meanings:

                     Affiliate: "Affiliate" means, with respect to any specified
person, (i) any other person directly or indirectly controlling or controlled
by, or under direct or indirect common control with, such specified person or
(ii) any officer or director of such other person. For purposes of this
definition, the term "control" (including the terms "controlling," "controlled
by" and "under common control with") of a person means the possession, direct or
indirect, of the power (whether or not exercised) to direct or cause the
direction of the management and policies of a person, whether through the
ownership of voting securities, by contract, or otherwise.

                     Business Day: Each Monday, Tuesday, Wednesday, Thursday and
Friday that is not a day on which banking institutions in The City of New York
are authorized or obligated by law or executive order to close.

                     Common Stock: The shares of common stock, par value $.10
per share, of the Company and any other shares of stock as may constitute
"Common Stock" for purposes of the Indenture, in each case, as issuable or
issued upon conversion of the Debentures.

                     Damages Accrual Period: See Section 2(f) hereof.






                     Damages Payment Date: Each of the semi-annual interest
payment dates provided in the Indenture.

                     Debentures: 7% Convertible Subordinated Debentures due 2005
of the Company being issued and sold pursuant to the Purchase Agreement and the
Indenture.

                     Deferral Period:  See Section 2(e) hereof.

                     Effectiveness Period: The period commencing with the date
hereof and ending on the date that all Registrable Securities (other than
Registerable Securities held by Affiliates of the Company) have ceased to be
Registrable Securities.

                     Event:  See Section 2(f) hereof.

                     Event Date:  See Section 2(f) hereof.

                     Exchange Act: The Securities Exchange Act of 1934, as
amended, and the rules and regulations of the SEC promulgated thereunder.

                     Filing Date:  See Section 2(a) hereof.

                     Holder:  See the second paragraph of this Agreement.

                     Indenture: The Indenture, dated as of December 15, 1998,
between the Company and The Chase Manhattan Bank, as Trustee, pursuant to which
the Debentures are being issued, as amended or supplemented from time to time in
accordance with the terms thereof.

                     Initial Purchasers: Morgan Stanley & Co. Incorporated and
Salomon Smith Barney Inc.

                     Initial Shelf Registration:  See Section 2(a) hereof.

                     Liquidated Damages:  See Section 2(f) hereof.

                     Losses:  See Section 6 hereof.

                     Managing Underwriters: The investment banking firm or firms
that shall manage or co-manage an Underwritten Offering.

           Notice and Questionnaire: A written notice delivered to the Company
containing substantially the information called for by the Notice and
Questionnaire attached as Appendix B to the Offering Memorandum of the Company
relating to the Debentures.

                     Notice Holder:  See Section 2(d) hereof.






                     Prospectus: The prospectus included in any Registration
Statement (including, without limitation, a prospectus that discloses
information previously omitted from a prospectus filed as part of an effective
registration statement in reliance upon Rule 430A promulgated under the
Securities Act), as amended or supplemented by an amendment or prospectus
supplement, including post-effective amendments, and all material incorporated
by reference or deemed to be incorporated by reference in such Prospectus.

                     Purchase Agreement: See the first paragraph of this
Agreement.

                     Record Holder: (i) With respect to any Damages Payment Date
relating to any Debenture as to which any such Liquidated Damages have accrued,
the registered holder of such Debenture on the record date with respect to the
interest payment date under the Indenture on which such Damages Payment Date
shall occur and (ii) with respect to any Damages Payment Date relating to any
Common Stock as to which any such Liquidated Damages have accrued, the
registered holder of such Common Stock fifteen (15) days prior to the next
succeeding Damages Payment Date.

                     Registrable Securities: (A) The Common Stock of the Company
into which the Debentures are convertible or converted, whether or not such
Debentures have been converted, and any Common Stock issued with respect thereto
upon any stock dividend, split or similar event until, in the case of any such
Common Stock, (i) it is effectively registered under the Securities Act and
resold in accordance with the Registration Statement covering it, (ii) it is
saleable by the holder thereof pursuant to Rule 144(k) (or any successor
provision) or (iii) it is sold to the public pursuant to Rule 144, and, as a
result of the event or circumstance described in any of the foregoing clauses
(i) through (iii), the legends with respect to transfer restrictions required
under the Indenture (other than any such legends required solely as the
consequence of the fact that such Common Stock (or the Debentures, upon the
conversion of which, such Common Stock was issued or is issuable) is owned by,
or was previously owned by, the Company or an Affiliate of the Company) are
removed or removable in accordance with the terms of the Indenture; (B) the
Debentures, until, in the case of such Debenture, (i) it is converted into
shares of Common Stock in accordance with the terms of the Indenture, (ii) it is
effectively registered under the Securities Act and resold in accordance with
the Registration Statement covering it, (iii) it is saleable by the holder
thereof pursuant to Rule 144(k) or (iv) it is sold to the public pursuant to
Rule 144, and, as a result of the event or circumstance described in any of the
foregoing clauses (ii) through (iv), the legends with respect to transfer
restrictions required under the Indenture (other than any such legends required
solely as the consequence of the fact that such Debenture is owned by, or was
previously owned by, the Company or an Affiliate of the Company) are removed or
removable in accordance with the terms of the Indenture.

                     Registration Statement: Any registration statement of the
Company which covers any of the Registrable Securities pursuant to the
provisions of this Agreement, including the Prospectus, amendments and
supplements to such registration






statement, including post-effective amendments, all exhibits, and all material
incorporated by reference or deemed to be incorporated by reference in such
registration statement.

                     Rule 144: Rule 144 under the Securities Act, as such Rule
may be amended from time to time, or any similar rule or regulation hereafter
adopted by the SEC.

                     Rule 144A: Rule 144A under the Securities Act, as such Rule
may be amended from time to time, or any similar rule or regulation hereafter
adopted by the SEC.

                     SEC:  The Securities and Exchange Commission.

                     Securities Act: The Securities Act of 1933, as amended, and
the rules and regulations promulgated by the SEC thereunder.

                     Shelf Registration:  See Section 2(a) hereof.

                     Special Counsel: Ropes & Gray, or such successor counsel as
shall be specified by the Holders of a majority of the Registrable Securities,
the fees and expenses of which will be paid by the Company pursuant to Section 5
hereof.

                     Subsequent Shelf Registration:  See Section 2(b) hereof.

                     TIA:  The Trust Indenture Act of 1939, as amended.

                     Trustee:  The Trustee under the Indenture.

                     Underwritten Registration or Underwritten Offering: A
registration in which securities of the Company are sold to an underwriter for
reoffering to the public.

     2.    Shelf Registration.

          (a) Shelf Registration. The Company shall prepare and file with the
SEC, as soon as practicable but in any event on or prior to the date ninety (90)
days following the Closing Date of the original issuance of the Debentures (the
"Filing Date"), a Registration Statement for an offering to be made on a
continuous basis pursuant to Rule 415 of the Securities Act (a "Shelf
Registration") registering the resale from time to time by Holders thereof of
all of the Registrable Securities (the "Initial Shelf Registration"). The
Initial Shelf Registration shall be on Form S-1, Form S-3 or another appropriate
form permitting registration of such Registrable Securities for resale by the
Holders in the manner or manners designated by them. If the Holders of
Registrable Securities so elect, an offering of Registrable Securities pursuant
to the Shelf Registration may be effected in the form of an Underwritten
Offering; provided, however, that the Company shall not be obligated to arrange
for more than one (1) such Underwritten Offering. In any Underwritten Offering,
the Holders of a majority of the Registrable Securities requested to be sold
shall select the Managing Underwriter (subject to the consent of the Company,
which consent shall not be unreasonably withheld) of such Underwritten Offering.
The Company shall






use reasonable best efforts to cause the Initial Shelf Registration to be
declared effective under the Securities Act as promptly as practicable and to
keep the Initial Shelf Registration continuously effective under the Securities
Act until the earlier of the expiration of the Effectiveness Period or the date
a Subsequent Shelf Registration, as defined below, covering all of the
Registrable Securities has been declared effective under the Securities Act.

          (b) If the Initial Shelf Registration or any Subsequent Shelf
Registration, as defined below, ceases to be effective for any reason as a
result of the issuance of a stop order by the SEC at any time during the
Effectiveness Period, the Company shall use its reasonable best efforts to
obtain the prompt withdrawal of any order suspending the effectiveness thereof,
and in any event shall within thirty (30) days of such cessation of
effectiveness amend the Shelf Registration in a manner reasonably expected to
obtain the withdrawal of the order suspending the effectiveness thereof, or file
an additional Shelf Registration covering all of the Registrable Securities (a
"Subsequent Shelf Registration"). If a Subsequent Shelf Registration is filed,
the Company shall use its reasonable best efforts to cause the Subsequent Shelf
Registration to be declared effective as soon as practicable after such filing
and to keep such Registration Statement continuously effective until the end of
the Effectiveness Period.

          (c) The Company shall supplement and amend the Shelf Registration if
required by the rules, regulations or instructions applicable to the
registration form used by the Company for such Shelf Registration, if required
by the Securities Act, or if reasonably requested by the Initial Purchasers or
by the Trustee on behalf of a majority of the Holders of the Registrable
Securities covered by such Registration Statement or by any Managing Underwriter
of such Registrable Securities in the event of an Underwritten Offering of the
Registrable Securities.

          (d) Each Holder of Registrable Securities agrees that if such Holder
wishes to sell its Registrable Securities pursuant to a Shelf Registration and
related Prospectus, it will do so only in accordance with this Section 2(d).
Each Holder of Registrable Securities agrees to deliver a Notice and
Questionnaire to the Company at least three (3) Business Days prior to any
intended distribution of Registrable Securities under the Shelf Registration. As
soon as practicable after the date the Notice and Questionnaire is provided to
the Company, and in any event within five (5) Business Days after such date (or,
if later, the filing of the Initial Shelf Registration), the Company shall (i)
if necessary, prepare and file with the SEC a post-effective amendment to the
Shelf Registration or a supplement to the related Prospectus or a supplement or
amendment to any document incorporated therein by reference or file any other
required document so that such Registration Statement will not 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
so that, as thereafter delivered to purchasers of the Registrable Securities
being sold thereunder, such Prospectus will not 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, in light of the circumstances under
which they were made, not misleading; (ii) provide each Holder who has delivered
a completed Notice and






Questionnaire in accordance with this Section 2(d) (each, a "Notice Holder")
copies of any documents filed pursuant to Section 2(d)(i); and (iii) inform each
Notice Holder that the Company has complied with its obligation in Section
2(d)(i) (or that, if the Company has filed a post-effective amendment to the
Shelf Registration which has not yet been declared effective, the Company will
notify the Notice Holder to that effect, will use its reasonable best efforts to
secure the effectiveness of such post-effective amendment and will immediately
notify the Notice Holder when the amendment has become effective). Each Notice
Holder shall furnish such other information with respect to such Holder and the
intended method of distribution as required to amend the Shelf Registration or
supplement the related Prospectus.

          (e) In the event, following the initial declaration of effectiveness
of the Initial Shelf Registration filed hereunder, (i) of the happening of any
event of the kind described in Section 3(c)(ii), 3(c)(iii), 3(c)(iv), 3(c)(v) or
3(c)(vi) hereof or (ii) that, in the judgment of the Company, it is advisable to
suspend use of the Prospectus for a discrete period of time due to pending
material corporate developments or similar material events that have not yet
been publicly disclosed and as to which the Company believes public disclosure
will be prejudicial to the Company, the Company shall deliver a certificate in
writing, signed by an authorized executive officer of the Company, to the Notice
Holders (including any Notice Holder providing a Notice and Questionnaire
subsequent to the delivery by the Company of the certificate referenced above),
the Special Counsel and the Managing Underwriters, if any, to the effect of the
foregoing and, upon receipt of such certificate, each such Notice Holder shall
not sell any Registrable Securities and shall not use the Prospectus until such
Notice Holder's receipt of copies of the supplemented or amended Prospectus
provided for in Section 2(d)(i) hereof, or until it is advised in writing by the
Company that the Prospectus may be used and has received copies of any
additional or supplemental filings that are incorporated or deemed incorporated
by reference in such Prospectus. The Company will use its reasonable best
efforts to ensure that the use of the Prospectus may be resumed, and sales of
Registrable Securities can commence or resume, as soon as practicable and, in
the case of a pending development or event referred to in Section 2(e)(ii)
hereof, as soon as the earlier of (x) public disclosure of such pending material
corporate development or similar material event or (y) in the judgment of the
Company, public disclosure of such material corporate development or similar
material event would not be prejudicial to the Company. Notwithstanding any
other provision in this Agreement, the Company shall not under any circumstances
be entitled to exercise its rights under this Section 2(e) to defer sales of
Registrable Securities except as follows: the Company may defer sales of
Registrable Securities in accordance with this Section 2(e) for a period not to
exceed an aggregate of sixty (60) days in any three hundred sixty five (365) day
period, and the period in which sales of Registrable Securities are suspended
shall not exceed fifteen (15) days unless the Company shall deliver to such
Notice Holders one or more subsequent notices to the effect set forth above,
each of which shall have the effect of extending the period during which sales
of Registrable Securities are deferred by up to an additional fifteen (15) days,
or such shorter period of time as is specified in such subsequent notice (each
such period of deferral, as may be extended, a "Deferral Period").






          (f) The parties hereto agree that the Holders of Registrable
Securities will suffer damages, and that it would not be feasible to ascertain
the extent of such damages with precision, if (i) the Initial Shelf Registration
had not been filed on or prior to the Filing Date, (ii) prior to the end of the
Effectiveness Period, the SEC shall have issued a stop order suspending the
effectiveness of the Shelf Registration or proceedings have been initiated with
respect to the Shelf Registration under Section 8(d) or 8(e) of the Securities
Act, or (iii) the aggregate number of days in the Deferral Periods in any three
hundred sixty five (365) day period exceeds the period permitted pursuant to
Section 2(e) hereof (each of the events of a type described in any of the
foregoing clauses (i) through (iii) are individually referred to herein as an
"Event," and the Filing Date in the case of clause (i), the date on which the
effectiveness of the Shelf Registration has been suspended or proceedings with
respect to the Shelf Registration under Section 8(d) or 8(e) of the Securities
Act have been commenced in the case of clause (ii), and the date on which the
duration of the Deferral Periods in any three hundred sixty five (365) day
period exceeds the period permitted by Section 2(e) hereof in the case of clause
(iii) being referred to herein as an "Event Date"). Events shall be deemed to
continue until the date of the termination of such Event, which shall be the
following dates with respect to the respective types of Events: the date the
Initial Registration Statement is filed in the case of an Event of the type
described in clause (i), the date that all stop orders suspending effectiveness
of the Shelf Registration have been removed and the proceedings initiated with
respect to the Shelf Registration under Section 8(d) or 8(e) of the Securities
Act have terminated, as the case may be, in the case of Events of the types
described in clause (ii), and termination of the Deferral Period which caused
the aggregate number of days in the Deferral Periods in any three hundred sixty
five (365) day period to exceed the number permitted by Section 2(e) to be
exceeded in the case of Events of the type described in clause (iii).

                     Accordingly, upon the occurrence of any Event and until
such time as there are no Events which have occurred and are continuing (a
"Damages Accrual Period"), commencing on the Event Date on which such Damages
Accrual Period began, the Company agrees to pay, as liquidated damages, and not
as a penalty, an additional amount (the "Liquidated Damages"): (A)(i) to each
holder of a Debenture that is a Notice Holder, accruing at an annual rate equal
to one-quarter of one percent per annum (25 basis points) on the aggregate
principal amount of Debentures held by such Notice Holder and (ii) to each
holder of Common Stock that is a Notice Holder, accruing at an annual rate equal
to one-quarter of one percent per annum (25 basis points) calculated on an
amount equal to the product of (x) the then-applicable Conversion Price (as
defined in the Indenture) or, in the event that each Debenture has been
converted to Common Stock, the Conversion Price applicable to the Debenture last
converted, multiplied by (y) the number of shares of Common Stock held by such
holder; and (B) if the Damages Accrual Period continues for a period in excess
of thirty (30) days from the Event Date, from and after the end of such thirty
(30) days until such time as there are no Events which have occurred and are
continuing, (i) to each holder of a Debenture (whether or not a Notice Holder),
accruing at an annual rate equal to one-half of one percent per annum (50 basis
points) on the aggregate principal amount of Debentures held by such holder and
(ii) to each holder of Common Stock into which Debentures have been converted
(whether or






not a Notice Holder), accruing at an annual rate equal to one-half of one
percent per annum (50 basis points) calculated on an amount equal to the product
of (x) the then applicable Conversion Price (as defined in the Indenture) or, in
the event that each Debenture has been converted to Common Stock, the Conversion
Price applicable to the Debenture last converted, multiplied by (y) the number
of shares of Common Stock held by such holder. Notwithstanding the foregoing, no
Liquidated Damages shall accrue under clause (A) for the preceding sentence
during any period for which Liquidated Damages accrue under clause (B) of the
preceding sentence or as to any Registrable Securities from and after the
expiration of the Effectiveness Period. The rate of accrual of the Liquidated
Damages with respect to any period shall not exceed the rate provided for in
this paragraph notwithstanding the occurrence of multiple concurrent Events.

                     The Company shall pay the Liquidated Damages due on any
Debentures or Common Stock by depositing with the Trustee under the Indenture,
in trust, for the benefit of the holders of Debentures or Common Stock or Notice
Holders, as the case may be, entitled thereto, at least one (1) Business Day
prior to the applicable Damages Payment Date, sums sufficient to pay the
Liquidated Damages accrued or accruing since the last preceding Damages Payment
Date through such Damages Payment Date. The Liquidated Damages shall be paid by
the Trustee at the direction and on behalf of the Company to the Record Holders
on each Damages Payment Date by wire transfer of immediately available funds to
the accounts specified by them or by mailing checks to their registered
addresses as they appear in the Debenture register (as defined in the
Indenture), in the case of the Debentures, and in the register of the Company
for the Common Stock, in the case of the Common Stock, if no such accounts have
been specified on or before the Damages Payment Date; provided, however, that
any Liquidated Damages accrued with respect to any Debenture or portion thereof
called for redemption on a redemption date, redeemed or repurchased in
connection with a Fundamental Change (as defined in the Indenture) on a
repurchase date, or converted into Common Stock on a conversion date prior to
the Damages Payment Date, shall, in any such event, be paid instead to the
holder who submitted such Debenture or portion thereof for redemption,
repurchase or conversion on the applicable redemption date, repurchase date or
conversion date, as the case may be, on such date (or promptly following the
conversion date, in the case of conversion of a Debenture). The Trustee shall be
entitled, on behalf of the holders of Debentures, holders of Common Stock and
Notice Holders, to seek any available remedy for the enforcement of this
Agreement, including for the payment of such Liquidated Damages. Notwithstanding
the foregoing, the parties agree that the sole damages payable for a violation
of the terms of this Agreement with respect to which Liquidated Damages are
expressly provided shall be such Liquidated Damages. Nothing shall preclude a
Notice Holder or Holder of Registrable Securities from pursuing or obtaining
specific performance or other equitable relief with respect to this Agreement,
in addition to the payment of Liquidated Damages.

                     All of the Company's obligations set forth in this Section
2(f) which are outstanding with respect to any Registrable Securities at the
time such security ceases to be a Registrable Security shall survive until such
time as all such obligations with respect






to such security have been satisfied in full (notwithstanding termination of the
Agreement pursuant to Section 8(o)).

                     The parties hereto agree that the Liquidated Damages
provided for in this Section 2(f) constitute a reasonable estimate of the
damages that may be incurred by Holders of Registrable Securities (other than
the Initial Purchasers) by reason of the failure of the Shelf Registration to be
filed or declared effective or unavailable (absolutely or as a practical matter)
for effecting resales of Registrable Securities, as the case may be, in
accordance with the provisions hereof.

     3. Registration Procedures. In connection with the Company's registration
obligations under Section 2 hereof, the Company shall effect such registrations
to permit the sale of the Registrable Securities in accordance with the intended
method or methods of disposition thereof, and pursuant thereto the Company
shall:

          (a) Prepare and file with the SEC a Registration Statement or
Registration Statements on any appropriate form under the Securities Act
available for the sale of the Registrable Securities by the Holders thereof in
accordance with the intended method or methods of distribution thereof, and use
its reasonable best efforts to cause each such Registration Statement to become
effective and remain effective as provided herein; provided that, before filing
any such Registration Statement or Prospectus or any amendments or supplements
thereto (other than documents that would be incorporated or deemed to be
incorporated therein by reference and that the Company is required by applicable
securities laws or stock exchange requirements to file), the Company shall
furnish to the Initial Purchasers, the Special Counsel and the Managing
Underwriters of such offering, if any, copies of all such documents proposed to
be filed, which documents will be subject to the review of the Initial
Purchasers, the Special Counsel and such Managing Underwriters, and the Company
shall not file any such Registration Statement or amendment thereto or any
Prospectus or any supplement thereto (other than such documents which, upon
filing, would be incorporated or deemed to be incorporated by reference therein
and that the Company is required by applicable securities laws or stock exchange
requirements to file) to which the Holders of a majority of the Registrable
Securities covered by such Registration Statement, the Managing Underwriters,
the Initial Purchasers or the Special Counsel shall reasonably object in writing
within five (5) full days after receipt of such materials in the case of the
Initial Shelf Registration Statement and two (2) full Business Days in every
other case.

          (b) Subject to Section 2(e), prepare and file with the SEC such
amendments and post-effective amendments to each Registration Statement as may
be necessary to keep such Registration Statement continuously effective for the
Effectiveness Period; cause the related Prospectus to be supplemented by any
required Prospectus supplement, and as so supplemented to be filed pursuant to
Rule 424 (or any similar provisions then in force) under the Securities Act; and
comply with the provisions of the Securities Act with respect to the disposition
of all securities covered by such Registration Statement and Prospectus during
the applicable period in accordance with the intended methods of






disposition by the sellers thereof set forth in such Registration Statement as
so amended or such Prospectus as so supplemented.

          (c) Notify all Notice Holders, the Initial Purchasers, the Special
Counsel and the Managing Underwriters, if any, promptly, and (if requested by
any such person) confirm such notice in writing, (i) when a Prospectus, any
Prospectus supplement, a Registration Statement or a post-effective amendment to
a Registration Statement has been filed with the SEC, and, with respect to a
Registration Statement or any post-effective amendment, when the same has become
effective, (ii) of any request by the SEC or any other federal or state
governmental authority for amendments or supplements to a Registration Statement
or related Prospectus or for additional information, (iii) of the issuance by
the SEC or any other federal or state governmental authority of any stop order
suspending the effectiveness of a Registration Statement or the initiation or
threatening of any proceedings for that purpose, (iv) of the receipt by the
Company of any notification with respect to the suspension of the qualification
or exemption from qualification of any of the Registrable Securities for sale in
any jurisdiction or the initiation or threatening of any proceeding for such
purpose, (v) of the existence of any fact or happening of any event which makes
any statement of a material fact in such Registration Statement or related
Prospectus or any document incorporated or deemed to be incorporated therein by
reference untrue or which would require the making of any changes in the
Registration Statement or Prospectus in order that, in the case of the
Registration Statement, it will not contain any 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 not misleading, and that in the case of
the Prospectus, it will not contain any 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 the light of the circumstances under which they
were made, not misleading and (vi) of the Company's determination that a
post-effective amendment to a Registration Statement or a supplement to a
Prospectus would be required. Notice of the filing and effectiveness of the
Initial Shelf Registration and any Subsequent Registration shall be made by the
Company by release made to Reuters Economic Services and Bloomberg Business
News.

          (d) Use its reasonable best efforts to obtain the withdrawal of any
order suspending the effectiveness of a Registration Statement, or the lifting
of any suspension of the qualification (or exemption from qualification) of any
of the Registrable Securities for sale in any jurisdiction, at the earliest
possible moment.

          (e) If reasonably requested by the Initial Purchasers or the Managing
Underwriters, if any, or the Holders of a majority of the Registrable Securities
being sold, (i) promptly incorporate in a Prospectus supplement or
post-effective amendment to a Registration Statement such information as the
Initial Purchasers, the Special Counsel, the Managing Underwriters, if any, or
such Holders, in connection with any offering of Registrable Securities, agree
should be included therein as required by applicable law and (ii) make all
required filings of such Prospectus supplement or such post-effective amendment
as soon as reasonably practicable after the Company has received notification of
the matters to be incorporated in such Prospectus supplement or post-effective






amendment; provided, however, that the Company shall not be required to take any
actions under this Section 3(e) that are not, in the reasonable opinion of
counsel for the Company, in compliance with applicable law.

          (f) Furnish to each Notice Holder, the Special Counsel, the Initial
Purchasers and each Managing Underwriter, if any, without charge, at least one
conformed copy of the Registration Statement or Statements and any amendment
thereto, including financial statements but excluding schedules, all documents
incorporated or deemed to be incorporated therein by reference and all exhibits
(unless requested in writing by any such Notice Holder, Special Counsel, the
Initial Purchasers or Managing Underwriter).

          (g) Deliver to each Notice Holder, the Special Counsel, the Initial
Purchasers and each Managing Underwriter, if any, in connection with any
offering of Registrable Securities, without charge, as many copies of the
Prospectus or Prospectuses relating to such Registrable Securities (including
each preliminary prospectus) and any amendment or supplement thereto as such
persons may reasonably request; and the Company hereby consents to the use of
such Prospectus or each amendment or supplement thereto by each of the Notice
Holders of Registrable Securities and the underwriters, if any, in connection
with any offering and sale of the Registrable Securities covered by such
Prospectus or any amendment or supplement thereto.

          (h) Prior to any public offering of Registrable Securities, to
register or qualify or cooperate with the Notice Holders, the Managing
Underwriters, if any, and the Special Counsel in connection with the
registration or qualification (or exemption from such 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 Notice Holder or Managing Underwriter reasonably requests in writing; keep
each such registration or qualification (or exemption therefrom) effective
during the period such Registration Statement is required to be kept effective
and do any all other acts or things necessary or advisable to enable the
disposition in such jurisdictions of the Registrable Securities covered by the
applicable Registration Statement; provided, however, that the Company will not
be required to (i) qualify generally to do business in any jurisdiction where it
is not then so qualified or (ii) take any action that would subject it to
general service of process in suits or to taxation in any such jurisdiction
where it is not then so subject.

          (i) If required, cause the Registrable Securities covered by the
applicable Registration Statement to be registered with or approved by such
other governmental agencies or authorities within the United States, except as
may be required solely as a consequence of the nature of such Notice Holder, in
which case the Company will cooperate in all reasonable respects with the filing
of such Registration Statement and the granting of such approvals, as may be
necessary to enable the Notice Holder or Holders thereof or the Managing
Underwriters, if any, to consummate the disposition of such Registrable
Securities.

          (j) Other than during a Deferral Period, immediately upon the
existence of any fact or the occurrence of any event as a result of which a
Registration Statement shall






contain any 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
not misleading, or a Prospectus shall contain any 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 the light of the circumstances
under which they were made, not misleading, promptly prepare and file (subject
to the proviso in Section 3(a)) a post-effective amendment to each Registration
Statement or a supplement to the related Prospectus or any document incorporated
therein by reference or file any other required document (such as a Current
Report on Form 8-K) that would be incorporated by reference into the
Registration Statement so that the Registration Statement shall not contain any
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 not misleading,
and so that the Prospectus will not contain any 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 the light of the circumstances
under which they were made, not misleading, as thereafter delivered to the
purchasers of the Registrable Securities being sold thereunder, and, in the case
of a post-effective amendment to a Registration Statement, use its reasonable
best efforts to cause it to become effective as soon as practicable.

          (k) Enter into such agreements (including, in the event of an
Underwritten Offering, an underwriting agreement in form, scope and substance as
is customary in Underwritten Offerings) and take all such other actions in
connection therewith (including, in the event of an Underwritten Offering, those
reasonably requested by the Managing Underwriters, if any, or the Holders of a
majority of the Registrable Securities being sold) in order to expedite or
facilitate the disposition of such Registrable Securities and in such
connection, whether or not an underwriting agreement is entered into, and if the
registration is an underwritten registration, (i) make such representations and
warranties, subject to the Company's ability to do so, to the Holders of such
Registrable Securities and the underwriters with respect to the business of the
Company and its subsidiaries, the Registration Statement, Prospectus and
documents incorporated by reference or deemed incorporated by reference, if any,
in each case, in form, substance and scope as are customarily made by issuers to
underwriters in underwritten offerings (provided that the scope and substance
shall not be materially different than those contained in the Purchase
Agreement) and confirm the same if and when requested; (ii) use its reasonable
best efforts to obtain opinions of counsel to the Company and updates thereof
(which counsel and opinions (in form, scope and substance) shall be reasonably
satisfactory to the Managing Underwriters, if any, and Special Counsel)
addressed to each of the underwriters covering the matters customarily covered
in opinions requested in underwritten offerings; (iii) use its reasonable best
efforts to obtain "cold comfort" letters and updates thereof from the
independent certified public accountants of the Company (and, if necessary, any
other certified public accountants of any business acquired or to be acquired by
the Company for which financial statements and financial data are, or are
required to be, included in the Registration Statement), addressed to each of
the Managing Underwriters, if any, such letters to be in customary form and
covering matters of the type customarily covered in "cold comfort" letters in
connection with underwritten offerings; and (iv) deliver such documents and
certificates as may be reasonably requested






by the Special Counsel and the Managing Underwriters, if any, to evidence the
continued validity of the representations and warranties of the Company and its
subsidiaries made pursuant to clause (i) above and to evidence compliance with
any customary conditions contained in the underwriting agreement or other
agreement entered into by the Company. The above shall be done at each closing
under such underwriting or similar agreement as and to the extent required
thereunder.

          (l) If requested in connection with a disposition of Registrable
Securities pursuant to a Registration Statement, make available for inspection
by a representative of the Holders of Registrable Securities being sold, any
Managing Underwriter participating in any disposition of Registrable Securities,
if any, and any attorney or accountant retained by such Notice Holders or
underwriter, financial and other records, pertinent corporate documents and
properties of the Company and its subsidiaries, and cause the executive
officers, directors and employees of the Company and its subsidiaries, to supply
all information reasonably requested by any such representative, Managing
Underwriter, attorney or accountant in connection with such disposition, subject
to reasonable assurances by each such person that such information will only be
used in connection with matters relating to such Registration Statement;
provided, however, that such persons shall first agree in writing with the
Company that any information that is reasonably and in good faith designated by
the Company in writing as confidential at the time of delivery of such
information shall be kept confidential by such persons and shall be used solely
for the purposes of exercising rights under this Agreement, unless (i)
disclosure of such information is required by court or administrative order or
is necessary to respond to inquiries of regulatory authorities, (ii) disclosure
of such information is required by law, (iii) such information becomes generally
available to the public other than as a result of a disclosure or failure to
safeguard by any such person or (iv) such information becomes available to any
such person from a source other than the Company and such source is not bound by
a confidentiality agreement.

          (m) Comply with all applicable rules and regulations of the SEC and
make generally available to its securityholders earning statements (which need
not be audited) satisfying the provisions of Section 11(a) of the Securities Act
and Rule 158 thereunder (or any similar rule promulgated under the Securities
Act) no later than forty-five (45) days after the end of any twelve (12) month
period (or ninety (90) days after the end of any twelve (12) month period if
such period is a fiscal year) (i) commencing at the end of any fiscal quarter in
which Registrable Securities are sold to underwriters in a firm commitment or
best efforts underwritten offering and (ii) if not sold to underwriters in such
an offering, commencing on the first day of the first fiscal quarter of the
Company commencing after the effective date of a Registration Statement, which
statements shall cover said twelve (12) month period.

          (n) Cooperate with the Notice Holders of Registrable Securities to
facilitate the timely preparation and delivery of certificates representing
Registrable Securities to be sold and not bearing any restrictive legends; and
enable such Registrable Securities to be in such denominations and registered in
such names as such Holders may request.






          (o) Provide the Trustee under the Indenture and the transfer agent for
the Common Stock with printed certificates for the Registrable Securities which
are in a form eligible for deposit with The Depositary Trust Company.

          (p) Cause the Common Stock covered by the Registration Statement to be
listed on each securities exchange (or quoted on each automated quotation system
on which any of the Company's "Common Stock," as that term is defined in the
Indenture, is then listed or quoted) no later than the date the Registration
Statement is declared effective and, in connection therewith, to the extent
applicable, to make such filings under the Exchange Act (e.g., the filing of a
Registration Statement on Form 8-A) and to have such filings declared effective
thereunder.

          (q) Cooperate and assist in any filings required to be made with the
National Association of Securities Dealers, Inc.

     4. Holder's Obligations. Each Holder agrees, by acquisition of the
Debentures and Registrable Securities, that no Holder of Registrable Securities
shall be entitled to sell any of such Registrable Securities pursuant to a
Registration Statement or to receive a Prospectus relating thereto, unless such
Holder has furnished the Company with the Notice and Questionnaire required
pursuant to Section 2(d) hereof and such other information regarding such Holder
and the distribution of such Registrable Securities as may be required to be
included in the Registration Statement or the Prospectus or as the Company may
from time to time reasonably request. The Company may exclude from such
registration the Registrable Securities of any Holder who does not furnish such
information provided above for so long as such information is not so furnished.
Each Holder of Registrable Securities as to which any Registration Statement is
being effected agrees promptly to furnish to the Company all information
required to be disclosed in order to make the information previously furnished
to the Company by such Holder not misleading. Any sale of any Registrable
Securities by any Holder shall constitute a representation and warranty by such
Holder that the information relating to such Holder and its plan of distribution
is as set forth in the Prospectus delivered by such Holder in connection with
such disposition, that such Prospectus does not as of the time of such sale
contain any untrue statement of a material fact relating to such Holder or its
plan of distribution and that such Prospectus does not as of the time of such
sale omit to state any material fact relating to such Holder or its plan of
distribution necessary to make the statements in such Prospectus, in light of
the circumstances under which they were made, not misleading.

     5. Registration Expenses. All fees and expenses incident to the Company's
performance of or compliance with this Agreement shall be borne by the Company
whether or not any of the Registration Statements become effective. Such fees
and expenses shall include, without limitation, (i) all registration and filing
fees (including, without limitation, fees and expenses (x) with respect to
filings required to be made with the SEC or the National Association of
Securities Dealers, Inc. and (y) relating to compliance with federal securities
or Blue Sky laws (including, without limitation, reasonable fees and
disbursements of Special Counsel in connection with Blue Sky






qualifications of the Registrable Securities under the laws of such
jurisdictions as the Managing Underwriters, if any, or Holders of a majority of
the Registrable Securities being sold may designate)), (ii) printing expenses
(including, without limitation, expenses of printing certificates for
Registrable Securities in a form eligible for deposit with The Depository Trust
Company and of printing prospectuses if the printing of prospectuses is
requested by the Special Counsel or the Holders of a majority of the Registrable
Securities included in any Registration Statement), (iii) the reasonable fees
and disbursements of the Trustee and its counsel and of the registrar and
transfer agent for the Common Stock, (iv) reasonable fees and disbursements of
counsel for the Company and the Special Counsel in connection with the Shelf
Registration (provided that the Company shall not be liable for the fees and
expenses of more than one separate firm, in addition to counsel for the Company,
for all parties participating in any transaction hereunder), (v) fees and
disbursements of all independent certified public accountants referred to in
Section 3(k)(iii) hereof (including the expenses of any special audit and "cold
comfort" letters required by or incident to such performance) and (vi)
Securities Act liability insurance, to the extent obtained by the Company in its
sole discretion. In addition, the Company shall pay its internal expenses
(including, without limitation, all salaries and expenses of its officers and
employees performing legal or accounting duties), the expense of any annual
audit, the fees and expenses incurred in connection with the listing of the
securities to be registered on any securities exchange on which similar
securities issued by the Company are then listed and the fees and expenses of
any person, including special experts, retained by the Company. Notwithstanding
the provisions of this Section 5, each seller of Registrable Securities shall
pay all underwriting discounts, selling commissions and stock transfer taxes
applicable to the Registrable Securities, all selling expenses and all
registration expenses to the extent that the Company is prohibited by applicable
Blue Sky laws from paying such expenses for or on behalf of such seller of
Registrable Securities.

     6.    Indemnification.

          (a) Indemnification by the Company. The Company shall indemnify and
hold harmless the Initial Purchasers, each Holder and each person, if any, who
controls the Initial Purchasers or any Holder (within the meaning of either
Section 15 of the Securities Act or Section 20(a) of the Exchange Act) from and
against all losses, liabilities, damages and expenses (including, without
limitation, any reasonable legal or other expenses reasonably incurred in
connection with defending or investigating any such action or claim)
(collectively, "Losses"), arising out of or based upon any untrue statement or
alleged untrue statement of a material fact contained in any Registration
Statement or Prospectus or in any amendment or supplement thereto or in any
preliminary prospectus, or arising out of or based upon 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 arise out of or are based upon the information relating to the Initial
Purchasers or any Holder furnished to the Company in writing by the Initial
Purchasers or such Holder expressly for use therein (including, without
limitation, any information relating to the plan of distribution of Registrable
Securities furnished by such person); provided that the Company shall not be
liable to






any Holder of Registrable Securities (or any person controlling such Holder) to
the extent that any such Losses arise out of or are based upon an untrue
statement or alleged untrue statement or omission or alleged omission made in
any preliminary prospectus if either (A)(i) such Holder failed to send or
deliver a copy of the Prospectus with or prior to the delivery of written
confirmation of the sale by such Holder to the person asserting the claims from
which such Losses arise and (ii) the Prospectus would have corrected such untrue
statement or alleged untrue statement or such omission or alleged omission, or
(B)(x) such untrue statement or alleged untrue statement, omission or alleged
omission is corrected in an amendment or supplement to the Prospectus and (y)
having previously been furnished by or on behalf of the Company with copies of
the Prospectus as so amended or supplemented, such Holder thereafter fails to
deliver such Prospectus as so amended or supplemented, with or prior to the
delivery of written confirmation of the sale of a Registrable Security to the
person asserting the claim from which Losses arise. The Company shall also
indemnify each underwriter and each person who controls such person (within the
meaning of Section 15 of the Securities Act or Section 20(a) of the Exchange
Act) to the same extent and with the same limitations as provided above with
respect to the indemnification of the Initial Purchasers or the Holders of
Registrable Securities.

          (b) Indemnification by Holder of Registrable Securities. Each Holder
agrees, and such agreement shall be evidenced by the Holder delivering the
Notice and Questionnaire described in Section 2(d) hereof, severally and not
jointly to indemnify and hold harmless the Initial Purchasers, the other
Holders, the Company, its directors, its officers who sign a Registration
Statement, and each person, if any, who controls the Company, the Initial
Purchasers and any other Holder (within the meaning of either Section 15 of the
Securities Act or Section 20 of the Exchange Act), from and against all losses
arising out of or based upon any untrue statement of a material fact contained
in any Registration Statement, Prospectus or preliminary prospectus or arising
out of or based upon any omission of a material fact required to be stated
therein or necessary to make the statements therein not misleading, to the
extent, but only to the extent, that such untrue statement or omission is
contained in any information relating to such Holder so furnished in writing by
such Holder to the Company expressly for use in such Registration Statement or
Prospectus. In no event shall the liability of any Holder of Registrable
Securities hereunder be greater in amount than the dollar amount of the proceeds
received by such Holder upon the sale of the Registrable Securities giving rise
to such indemnification obligation.

          (c) Conduct of Indemnification Proceedings. 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 of the two
preceding paragraphs, such person (the "indemnified party") shall promptly
notify the person against whom such indemnity may be sought (the "indemnifying
party") in writing and the indemnifying party, shall have the right to assume
the defense of such proceeding and to 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 or
(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 because there may be
one or more legal defenses available to the indemnified party that conflicts
with 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 (a) the fees and expenses of more than one
separate firm (in addition to any local counsel) for the Initial Purchasers and
all persons, if any, who control the Initial Purchasers within the meaning of
either Section 15 of the Securities Act or Section 20 of the Exchange Act, (b)
the fees and expenses of more than one separate firm (in addition to any local
counsel) for all Holders and all persons, if any, who control any Holder within
the meaning of either Section 15 of the Securities Act or Section 20 of the
Exchange Act, and (c) the fees and expenses of more than one separate firm (in
addition to any local counsel) for the Company, its directors, its officers who
sign a Registration Statement and each person, if any, who controls the Company
within the meaning of either such Section, and that all such fees and expenses
shall be reimbursed as they are incurred. In the case of any such separate firm
for the Company, and such directors, officers and the control persons of the
Company, such firm shall be designated in writing by the Company. In such case
involving the Initial Purchasers and persons who control the Initial Purchasers,
such firm shall be designated in writing by Morgan Stanley & Co. Incorporated.
In such case involving the Holders and such persons who control Holders, such
firm shall be designated in writing by the Holders of the majority of
Registrable Securities sold pursuant to the Registration Statement. 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 or claims that are the subject matter
of such proceeding.

          (d) Contribution. If the indemnification provided for in this Section
6 is unavailable to an indemnified party under Section 6(a) or 6(b) hereof in
respect of any Losses or is insufficient to hold such indemnified party
harmless, then each applicable indemnifying party, in lieu of indemnifying such
indemnified party, shall contribute to the amount paid or payable by such
indemnified party as a result of such Losses, (i) in such proportion as is
appropriate to reflect the relative benefits received by the indemnifying party
or parties on the one hand and the indemnified party or parties on the other
hand or (ii) if the allocation provided by clause (i) above is not permitted by
applicable law, in such proportion as is appropriate to reflect not only the
relative benefits referred to in






clause (i) above but also the relative fault of the indemnifying party or
parties on the one hand and of the indemnified party or parties on the other
hand in connection with the statements or omissions that resulted in such
Losses, as well as any other relevant equitable considerations. Benefits
received by the Company shall be deemed to be equal to the total net proceeds
from the initial placement (before deducting expenses) of the Debentures
pursuant to the Purchase Agreement. Benefits received by the Initial Purchasers
shall be deemed to be equal to the total purchase discounts and commissions
received by them pursuant to the Purchase Agreement and benefits received by any
other Holders shall be deemed to be equal to the value of receiving Debentures
registered under the Securities Act. Benefits received by any underwriter shall
be deemed to be equal to the total discounts and commissions, as set forth on
the cover page of the Prospectus forming a part of the Registration Statement
which resulted in such Losses. The relative fault of the Holders on the one hand
and the Company on the other hand shall be determined by reference to, among
other things, whether the untrue or alleged untrue statement of a material fact
or the omission or alleged omission to state a material fact relates to
information supplied by the Holders or by the Company and the parties' relative
intent, knowledge, access to information and opportunity to correct or prevent
such statement or omission. The Holders' respective obligations to contribute
pursuant to this paragraph are several in proportion to the respective number of
Registrable Securities they have sold pursuant to a Registration Statement, and
not joint.

                     The parties hereto agree that it would not be just and
equitable if contribution pursuant to this Section 6(d) were determined by pro
rata allocation or by any other method or allocation that does not take into
account the equitable considerations referred to in the immediately preceding
paragraph. The amount paid or payable by an indemnified party as a result of the
Losses referred to in the immediately preceding paragraph shall be deemed to
include, subject to the limitations set forth above, any legal or other expenses
reasonably incurred by such indemnified party in connection with investigating
or defending any such action or claim. Notwithstanding this Section 6(d), an
indemnifying party that is a Holder of Registrable Securities shall not be
required to contribute any amount in excess of the amount by which the total
price at which the Registrable Securities sold by such indemnifying party and
distributed to the public were offered to the public exceeds the amount of any
damages which such indemnifying party has otherwise been required to pay by
reason of such untrue or alleged untrue statement or omission or alleged
omission. 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 indemnity, contribution and expense reimbursement
obligations of the Company hereunder shall be in addition to any liability the
Company may otherwise have hereunder, under the Purchase Agreement or otherwise.
The provisions of this Section 6 shall survive so long as Registrable Securities
remain outstanding, notwithstanding any transfer of the Registrable Securities
by any Holder or any termination of this Agreement.

                     The indemnity and contribution provisions contained in this
Section 6 shall remain operative and in full force and effect regardless of (i)
any termination of this






Agreement, (ii) any investigation made by or on behalf of the Initial
Purchasers, any Holder or any person controlling any Initial Purchaser or any
Holder and (iii) the sale of any Registrable Securities by any Holder.

     7.    Information Requirements.

          (a) The Company shall file the reports required to be filed by it
under the Securities Act and the Exchange Act, and if at any time the Company is
not required to file such reports, it will, upon the request of any Holder of
Registrable Securities, make publicly available other information so long as
necessary to permit sales pursuant to Rule 144 and Rule 144A under the
Securities Act. The Company further covenants that it will cooperate with any
Holder of Registrable Securities and take such further reasonable action as any
Holder of Registrable Securities may reasonably request (including, without
limitation, making such reasonable representations as any such Holder may
reasonably request), all to the extent required from time to time to enable such
Holder to sell Registrable Securities without registration under the Securities
Act within the limitation of the exemptions provided by Rule 144 and Rule 144A
under the Securities Act. Upon the request of any Holder of Registrable
Securities, the Company shall deliver to such Holder a written statement as to
whether it has complied with such filing requirements. Notwithstanding the
foregoing, nothing in this Section 7 shall be deemed to require the Company to
register any of its securities under any such section of the Exchange Act.

          (b) The Company shall file the reports required to be filed by it
under the Exchange Act and shall comply with all other requirements set forth in
the instructions to Form S-3 in order to allow the Company to be eligible to
file registration statements on Form S-3.

     8.    Miscellaneous.

          (a) Remedies. In the event of a breach by the Company of its
obligations under this Agreement, each Holder of Registrable Securities, in
addition to being entitled to exercise all rights granted by law, including
recovery of damages, will be entitled to specific performance of its rights
under this Agreement, provided that the sole damages payable for a violation of
the terms of this Agreement for which Liquidated Damages are expressly provided
pursuant to Section 2(e) hereof shall be such Liquidated Damages. The Company
agrees that monetary damages would not be adequate compensation for any loss
incurred by reason of a breach by it of any of the provisions of this Agreement
and hereby further agrees that, in the event of any action for specific
performance in respect of such breach, it shall waive the defense that a remedy
at law would be adequate.

          (b) No Conflicting Agreements. The Company has not, as of the date
hereof, and shall not, on or after the date of this Agreement, enter into any
agreement with respect to its securities which conflicts with the rights granted
to the Holders of Registrable Securities in this Agreement. The Company
represents and warrants that the rights granted to the Holders or Registrable
Securities hereunder do not in any way conflict with the rights granted to the
holders of the Company's securities under any other agreements.






          (c) Amendments and Waivers. The provisions of this Agreement,
including the provisions of this sentence, may not be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may not be given, unless the Company has obtained the written consent of Holders
of a majority of the then outstanding Common Stock constituting Registrable
Securities (with Holders of Debentures deemed to be the Holders, for purposes of
this Section, of the number of outstanding shares of Common Stock into which
such Debentures are convertible as of such date of determination).
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
Registration Statement and that does not directly or indirectly affect the
rights of other Holders of Registrable Securities may be given by Holders of at
least a majority of the Registrable Securities being sold by such Holders;
provided that the provisions of this statement 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 made in writing and shall be deemed given (i) when
made, if made by hand delivery, (ii) upon confirmation, if made by telecopier or
(ii) one (1) business day after being deposited with a reputable next-day
courier, postage prepaid, to the parties as follows:

                     (i) if to a Holder of Registrable Securities, at the most
current address given by such Holder to the Company in accordance with the
provisions of Sections 8(e):

                     (ii) if to the Company, to:

                                        Sepracor Inc.
                                        33 Locke Drive
                                        Marlborough, MA  01752
                                        Attention: Chief Financial Officer
                                        Telecopy No: (508) 481-6700

                                        with a copy to:

                                        Hale and Dorr LLP
                                        60 State Street
                                        Boston, MA  02109
                                        Attention:  Mark G. Borden
                                        Telecopy No:  (617) 526-5000

                                        and







                     (iii) if to the Initial Purchasers or Special Counsel to:

                                         Ropes & Gray
                                         One International Place
                                         Boston, MA  02110
                                         Attention: Keith F. Higgins, Esq.
                                         Telecopy No:  (617) 951-7050

or to such other address as such person may have furnished to the other persons
identified in this Section 8(d) in writing in accordance herewith.

          (e) Owner of Registrable Securities. The Company will maintain, or
will cause its registrar and transfer agent to maintain, a register with respect
to the Registrable Securities in which all transfers of Registrable Securities
of which the Company has received notice will be recorded. The Company may deem
and treat the person in whose name Registrable Securities are registered in such
register of the Company as the owner thereof for all purposes, including without
limitation, the giving of notices under this Agreement.

          (f) Approval of Holders. Whenever the consent or approval of Holders
of a specified percentage of Registrable Securities is required hereunder, (i)
Holders of Debentures shall be deemed to be Holders, for such purposes, of the
number of outstanding shares of Common Stock into which such Debentures are
convertible and (ii) Registrable Securities held by the Company or its
affiliates (as such term is defined in Rule 405 under the Securities Act) (other
than the Initial Purchasers or subsequent Holders of Registrable Securities if
such subsequent Holders are deemed to be such affiliates solely by reason of
their holdings of such Registrable Securities) shall not be counted in
determining whether such consent or approval was given by the Holders of such
required percentage.

          (g) Successors and Assigns. Any person who purchases any Registrable
Securities from an Initial Purchaser shall be deemed, for purposes of this
Agreement, to be an assignee of such Initial Purchaser. This Agreement shall
inure to the benefit of and be binding upon the successors and assigns of each
of the parties and shall inure to the benefit of and be binding upon each Holder
of any Registrable Securities.

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

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

          (j) Governing Law.  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED
IN ACCORDANCE WITH THE LAWS OF THE STATE OF






NEW YORK AS APPLIED TO CONTRACTS MADE AND PERFORMED WITHIN THE STATE OF NEW YORK
WITHOUT REGARD TO PRINCIPLES OF CONFLICT OF LAWS.

          (k) Severability. If any term, provision, covenant or restriction of
this Agreement is held to be invalid, illegal, void or unenforceable, the
remainder of the terms, provisions, covenants and restrictions set forth herein
shall remain in full force and effect and shall in no way be affected, impaired
or invalidated thereby, and the parties hereto shall use their best efforts to
find and employ an alternative means to achieve the same or substantially the
same result as that contemplated by such term, provision, covenant or
restriction. It is hereby stipulated and declared to be in the intention of the
parties that they would have executed the remaining terms, provisions, covenants
and restrictions without including any of such which may be hereafter declared
invalid, illegal, void or unenforceable.

          (l) Entire Agreement. This Agreement is intended by the parties as a
final expression of their agreement and is intended to be a complete and
exclusive statement of the agreement and understanding of the parties hereto in
respect of the subject matter contained herein and the registration rights
granted by the Company with respect to the Registrable Securities. Except as
provided in the Purchase Agreement, there are no restrictions, promises,
warranties or undertakings, other than those set forth or referred to herein,
with respect to the registration rights granted by the Company with respect to
the Registrable Securities. This Agreement supersedes all prior agreements and
undertakings among the parties with respect to such registration rights.

          (m) Attorneys' Fees. In any action or proceeding brought to enforce
any provision of this Agreement, or where any provision hereof is validly
asserted as a defense, the prevailing party, as determined by the court, shall
be entitled to recover reasonable attorneys' fees in addition to any other
available remedy.

          (n) Further Assurances. Each of the parties hereto shall use all
reasonable efforts to take, or cause to be taken, all appropriate action, do or
cause to be done all things reasonably necessary, proper or advisable under
applicable law, and execute and deliver such documents and other papers, as may
be required to carry out the provisions of this Agreement and the other
documents contemplated hereby and consummate and make effective the transactions
contemplated hereby.

          (o) Termination. This Agreement and the obligations of the parties
hereunder shall terminate upon the end of the Effectiveness Period, except for
any liabilities or obligations under Section 4, 5 or 6 hereof and the
obligations to make payments of and provide for Liquidated Damages under Section
2(e) hereof to the extent such damages accrue prior to the end of the
Effectiveness Period, each of which shall remain in effect in accordance with
their terms.






                                                   Registration Rights Agreement


                     IN WITNESS WHEREOF, the parties have executed this
Agreement as of the date first written above.


                                       SEPRACOR INC.


                                       By:    /s/ Robert Scumaci
                                              ---------------------------------
                                              Name: Robert Scumaci
                                              Title:  Sr. Vice President


Accepted as of the date first above written:


MORGAN STANLEY & CO. INCORPORATED
SALOMON SMITH BARNEY INC.

By:    MORGAN STANLEY & CO. INCORPORATED


By:    /s/ W L Blais
       ----------------------------
       Name:  WL Blais
       Title:  Principal