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                                                                   Exhibit 10.35

                                                                  EXECUTION COPY

                          REGISTRATION RIGHTS AGREEMENT


            THIS REGISTRATION RIGHTS AGREEMENT (the "Agreement"), dated as of
February 5, 1998 by and among SEPRACOR INC., a Delaware corporation (the
"Company") and MORGAN STANLEY & CO. INCORPORATED, LEHMAN BROTHERS INC., SMITH
BARNEY INC. and VECTOR SECURITIES INTERNATIONAL, INC. (the "Initial Purchasers")
pursuant to the Purchase Agreement, dated as of February 5, 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.
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            DAMAGES ACCRUAL PERIOD: See Section 2(f) hereof.

            DAMAGES PAYMENT DATE: Each of the semi-annual interest payment dates
provided in the Indenture.

            DEBENTURES: 6 1/4_% 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 February 10, 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, Lehman
Brothers, Inc., Salomon Smith Barney and Vector Securities International, 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.


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            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.


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            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 (without
effect to the exercise of any over-allotment option) (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


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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 two (2) 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


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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


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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


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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


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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


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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.


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      (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


                                      -11-
   12
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

        
                                      -12-
   13
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


                                      -13-
   14
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


                                      -14-
   15
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


                                      -15-
   16
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


                                      -16-
   17
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


                                      -17-
   18
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


                                      -18-
   19
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


                                      -19-
   20
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


                                      -20-
   21
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


                                      -21-
   22
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


                                      -22-
   23
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.


                                      -23-
   24
            IN WITNESS WHEREOF, the parties have executed this Agreement as of
the date first written above.


                                          SEPRACOR INC.


                                          By: /s/David P. Southwell
                                             -----------------------------------
                                             Name:  David P. Southwell
                                             Title: Executive Vice President and
                                                         Chief Financial Officer


Accepted as of the date first above written:


MORGAN STANLEY & CO. INCORPORATED
LEHMAN BROTHERS INC.
SMITH BARNEY INC.
VECTOR SECURITIES INTERNATIONAL, INC.

By: MORGAN STANLEY & CO. INCORPORATED


By: /s/William H. Wright II
    -----------------------------------
    Name:    William H. Wright II
    Title:   Managing Director


                                      -24-