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                                                                   Exhibit 10.10



                          REGISTRATION RIGHTS AGREEMENT


                                 by and between


                        CABOT MICROELECTONICS CORPORATION


                                       and



                                CABOT CORPORATION



                           Dated as of March 28, 2000



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                                                                   Exhibit 10.10



                         REGISTRATION RIGHTS AGREEMENT


         This REGISTRATION RIGHTS AGREEMENT (this "Agreement"), is made as of
March 28, 2000, by and between CABOT MICROELECTRONICS CORPORATION, a Delaware
corporation (the "Company") and CABOT CORPORATION, a Delaware corporation
("Cabot").

         WHEREAS, as of the date hereof, the Company and its subsidiary and
Cabot and certain of its subsidiaries are entering into a Master Separation
Agreement (the "Master Separation Agreement"), pursuant to which, among other
things, Cabot and such subsidiaries are transferring to the Company, and the
Company and such subsidiary are assuming, certain assets and liabilities of the
Microelectronics Materials Division of Cabot;

         WHEREAS, as of the date hereof, the Company and Cabot are entering into
an IPO and Distribution Agreement (the "IPO and Distribution Agreement"),
pursuant to which, among other things, upon the occurrence of certain events,
the Company will effect an initial public offering of its Common Stock;

         WHEREAS, following the initial public offering by the Company, Cabot
intends to divest itself of its entire ownership of the Company through one or
more tax-free distributions to the holders of Cabot's common stock (the
"Distribution"); and

         WHEREAS, in connection with (i) the Company and Cabot entering into the
Master Separation Agreement, and (ii) the Company and Cabot entering into the
IPO and Distribution Agreement, the Company has agreed to provide the
registration rights set forth in this Agreement.

         ACCORDINGLY, the parties hereto agree as follows:

1.       Certain Definitions.

         As used in this Agreement, the following terms shall have the meanings
ascribed to them below:

         "Affiliate" means (i) with respect to any Person, any other Person
directly or indirectly controlling or controlled by or under direct or indirect
common control with such specified Person or (ii) with respect to any
individual, shall also mean the spouse or child of such individual; provided,
that neither the Company nor any Person controlled by the Company shall be
deemed to be an Affiliate of any Holder.

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         "Certificate of Incorporation" means the Certificate of Incorporation
of the Company, as amended.

         "Common Stock" means the Common Stock, par value $.001 per share, of
the Company and any equity securities issued or issuable with respect to the
Common Stock in connection with a reclassification, recapitalization, merger,
consolidation or other reorganization.

         "Common Stock Equivalents" means any securities convertible into, or
exercisable or exchangeable for, shares of Common Stock.

         "Holder" or "Holders" means any party who is a signatory to this
Agreement and, subject to Section 4.6(a), any party who shall hereafter acquire
and hold Registrable Securities.

         "IPO" means the initial underwritten offering pursuant to which the
Common Stock becomes registered under Section 12 of the Securities Exchange Act
of 1934, as amended (the "Exchange Act").

         "Major Holder" means with respect to any registration the Holder that,
together with its Affiliates, includes the largest number of Registrable
Securities in such registration.

         "Person" means any individual, corporation, limited liability company,
limited or general partnership, joint venture, association, joint-stock company,
trust, unincorporated organization or government or any agency or political
subdivisions thereof.

         "Registrable Securities" means any (a) shares of Common Stock held by
Cabot and (b) shares of Common Stock issued or issuable, directly or indirectly,
with respect to the Common Stock referenced in clause (a) above by way of stock
dividend, stock split or combination of shares. As to any particular Registrable
Securities, such securities shall cease to be Registrable Securities when (A) a
registration statement with respect to the sale of such Registrable Securities
shall have become effective under the Securities Act and such Registrable
Securities shall have been disposed of in accordance with such registration
statement; (B) such Shares shall have been sold to the public pursuant to Rule
144 under the Securities Act (or any successor provision); (C) such Registrable
Securities shall have been otherwise transferred, new certificates for them not
bearing a legend restricting further transfer shall have been delivered by the
Company and subsequent public distribution of them shall not require
registration or qualification of them under the Securities Act or any similar
state law then in force; and (D) such Registrable Securities shall have ceased
to be outstanding.

         "SEC" means the Securities and Exchange Commission.


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

2.       Registration Rights.

         2.1.     Demand Registrations.

                  (a) (i) Subject to Sections 2.1(b) and 2.3 below, at any time
and from time to time after the closing of an IPO and the delivery by Cabot to
the Company of written notice, pursuant to Section 2.6 of the IPO and
Distribution Agreement, that Cabot no longer intends to proceed with or complete
the Distribution (the "Registration Rights Trigger Date"), Cabot shall have the
right to require the Company to file a registration statement under the
Securities Act covering all or any part of its Registrable Securities, by
delivering a written request therefor to the Company specifying the number of
Registrable Securities to be included in such registration by Cabot and the
intended method of distribution thereof. All such requests by Cabot pursuant to
this Section 2.1(a)(i) are referred to herein as "Demand Registration Requests,"
and the registrations so requested are referred to herein as "Demand
Registrations" (with respect to any Demand Registration, the Holder making such
demand for registration being referred to as the "Initiating Holder"). As
promptly as practicable, but no later than ten days after receipt of a Demand
Registration Request, the Company shall give written notice (the "Demand
Exercise Notice") of such Demand Registration Request to all Holders of record
of Registrable Securities.

                      (ii) The Company, subject to Sections 2.3 and 2.6, shall
include in a Demand Registration (x) the Registrable Securities of the
Initiating Holder and (y) the Registrable Securities of any other Holder which
shall have made a written request to the Company for inclusion in such
registration (which request shall specify the maximum number of Registrable
Securities intended to be disposed of by such Holder) within 30 days after the
receipt of the Demand Exercise Notice (or, 15 days if, at the request of the
Initiating Holder or the Major Holder participating in such registration, the
Company states in such written notice or gives telephonic notice to all Holders,
with written confirmation to follow promptly thereafter, that such registration
will be on a Form S-3).

                      (iii) The Company shall, as expeditiously as possible, use
its best efforts to (x) effect such registration under the Securities Act
(including, without limitation, by means of a shelf registration pursuant to
Rule 415 under the Securities Act if so requested and if the Company is then
eligible to use such a registration) of the Registrable Securities which the
Company has been so requested to register, for distribution in accordance with
such intended method of distribution, and (y) if requested by the Initiating
Holder or the Major Holder participating in such registration, obtain
acceleration of the effective date of the registration statement relating to
such registration.


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                  (b) The Demand Registration rights granted in Section 2.1(a)
to the Holders are subject to the following limitations: (i) with respect to any
registration in respect of a Demand Registration Request initiated by a
transferee of Cabot, such registration statement must include shares of Common
Stock representing, in the aggregate (based on the Common Stock included in such
registration by Cabot), in excess of 20% of the sum of (x) the amount of shares
of Registrable Securities held, in the aggregate, by Cabot and its transferees
immediately prior to such registration plus (y) the amount of shares of Common
Stock obtainable upon the conversion of Common Stock Equivalents held, in the
aggregate, by Cabot and their transferees immediately prior to such
registration; (ii) the Company shall not be required to cause a registration
pursuant to Section 2.1(a)(i) to be declared effective within a period of 180
days after the effective date of any registration statement of the Company
effected in connection with a Demand Registration Request; and (iii) if the
Board of Directors of the Company, in its good faith judgment, determines that
any registration of Registrable Securities should not be made or continued
because it would materially interfere with any material financing, acquisition,
corporate reorganization or merger or other transaction involving the Company or
any of its subsidiaries (a "Valid Business Reason"), (x) the Company may
postpone filing a registration statement relating to a Demand Registration
Request until such Valid Business Reason no longer exists, but in no event for
more than three months, and (y) in case a registration statement has been filed
relating to a Demand Registration Request, if the Valid Business Reason has not
resulted from actions taken by the Company, the Company may cause such
registration statement to be withdrawn and its effectiveness terminated or may
postpone amending or supplementing such registration statement until such Valid
Business Reason no longer exists, but in no event for more than three months
(such period of postponement or withdrawal under subclauses (x) or (y) of this
clause (iv), the "Postponement Period"); and the Company shall give written
notice of its determination to postpone or withdraw a registration statement and
of the fact that the Valid Business Reason for such postponement or withdrawal
no longer exists, in each case, promptly after the occurrence thereof; provided,
however, the Company shall not be permitted to postpone or withdraw a
registration statement after the expiration of any Postponement Period until
twelve months after the expiration of such Postponement Period without the prior
written approval of Cabot.

                  If the Company shall give any notice of postponement or
withdrawal of any registration statement, the Company shall not, during the
period of postponement or withdrawal, register any Common Stock, other than
pursuant to a registration statement on Form S-4 or S-8 (or an equivalent
registration form then in effect). Each Holder of Registrable Securities agrees
that, upon receipt of any notice from the Company that the Company has
determined to withdraw any registration statement pursuant to clause (iii)
above, such Holder will discontinue its disposition of Registrable Securities
pursuant to such registration statement and, if so directed by the Company, will
deliver to the Company (at the Company's expense) all copies, other than
permanent file copies, then in


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such Holder's possession of the prospectus covering such Registrable Securities
that was in effect at the time of receipt of such notice. If the Company shall
have withdrawn or prematurely terminated a registration statement filed under
Section 2.1(a)(i) (whether pursuant to clause (iii) above or as a result of any
stop order, injunction or other order or requirement of the SEC or any other
governmental agency or court), the Company shall not be considered to have
effected an effective registration for the purposes of this Agreement until the
Company shall have filed a new registration statement covering the Registrable
Securities covered by the withdrawn registration statement and such registration
statement shall have been declared effective and shall not have been withdrawn.
If the Company shall give any notice of withdrawal or postponement of a
registration statement, the Company shall, at such time as the Valid Business
Reason that caused such withdrawal or postponement no longer exists (but in no
event later than three months after the date of the postponement or withdrawal),
use its best efforts to effect the registration under the Securities Act of the
Registrable Securities covered by the withdrawn or postponed registration
statement in accordance with this Section 2.1 (unless the Initiating Holder
shall have withdrawn such request, in which case the Company shall not be
considered to have effected an effective registration for the purposes of this
Agreement).

                  (c) The Company, subject to Sections 2.3 and 2.6, may elect to
include in any registration statement and offering made pursuant to Section
2.1(a)(i), (i) authorized but unissued shares of Common Stock or shares of
Common Stock held by the Company as treasury shares and (ii) any other shares of
Common Stock which are requested to be included in such registration pursuant to
the exercise of piggyback rights granted by the Company after the date hereof
which are not inconsistent with the rights granted in, or otherwise conflict
with the terms of, this Agreement ("Additional Piggyback Rights") provided,
however, that such inclusion shall be permitted only to the extent that it is
pursuant to and subject to the terms of the underwriting agreement or
arrangements, if any, entered into by the Initiating Holder.

                  (d) In connection with any Demand Registration, the Major
Holder participating in such registration shall have the right to designate the
lead managing underwriter, and subject to the next sentence, each other managing
underwriter for such registration, provided that each such other managing
underwriter is reasonably satisfactory to the Company, it being understood and
agreed that any managing underwriter that participates in the Company's IPO
shall be satisfactory to the Company. The Company shall have the right to
designate one managing underwriter other than the lead managing underwriter in
any such registration, provided that such other managing underwriter is
reasonably satisfactory to the Major Holder, it being understood and agreed that
any managing underwriter that participates in the Company's IPO shall be
satisfactory to the Major Holder.


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         2.2.     Piggyback Registrations.

                  (a) If, at any time after the Registration Rights Trigger
Date, the Company proposes or is required to register any of its equity
securities under the Securities Act (other than pursuant to (i) registrations on
such form or similar form(s) solely for registration of securities in connection
with an employee benefit plan or dividend reinvestment plan or a merger or
consolidation or (ii) a Demand Registration under Section 2.1) on a registration
statement on Form S-1, Form S-2 or Form S-3 (or an equivalent general
registration form then in effect), whether or not for its own account, the
Company shall give prompt written notice of its intention to do so to each of
the Holders of record of Registrable Securities. Upon the written request of any
such Holder, made within 20 days following the receipt of any such written
notice (which request shall specify the maximum number of Registrable Securities
intended to be disposed of by such Holder and the intended method of
distribution thereof), the Company shall, subject to Sections 2.2(b), 2.3 and
2.6 hereof, use its best efforts to cause all such Registrable Securities, the
Holders of which have so requested the registration thereof, to be registered
under the Securities Act (with the securities which the Company at the time
proposes to register) to permit the sale or other disposition by the Holders (in
accordance with the intended method of distribution thereof) of the Registrable
Securities to be so registered. There is no limitation on the number of such
piggyback registrations pursuant to the preceding sentence which the Company is
obligated to effect. No registration effected under this Section 2.2(a) shall
relieve the Company of its obligations to effect Demand Registrations.

                  (b) If, at any time after giving written notice of its
intention to register any equity securities and prior to the effective date of
the registration statement filed in connection with such registration, the
Company shall determine for any reason not to register or to delay registration
of such equity securities, the Company may, at its election, give written notice
of such determination to all Holders of record of Registrable Securities and (i)
in the case of a determination not to register, shall be relieved of its
obligation to register any Registrable Securities in connection with such
abandoned registration, without prejudice, however, to the rights of Holders
under Section 2.1, and (ii) in the case of a determination to delay such
registration of its equity securities, shall be permitted to delay the
registration of such Registrable Securities for the same period as the delay in
registering such other equity securities.

                  (c) Any Holder shall have the right to withdraw its request
for inclusion of its Registrable Securities in any registration statement
pursuant to this Section 2.2 by giving written notice to the Company of its
request to withdraw; provided, however, that (i) such request must be made in
writing prior to the earlier of the execution of the underwriting agreement or
the execution of the custody agreement with respect to such registration and
(ii) such withdrawal shall be irrevocable and, after making such


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withdrawal, a Holder shall no longer have any right to include Registrable
Securities in the registration as to which such withdrawal was made.

         2.3.     Allocation of Securities Included in Registration Statement.

                  (a) If any requested registration pursuant to Section 2.1
involves an underwritten offering and the lead managing underwriter of such
offering (the "Manager") shall advise the Company that, in its view, the number
of securities requested to be included in such registration by the Holders or
any other persons (including those shares of Common Stock requested by the
Company to be included in such registration) exceeds the largest number (the
"Section 2.1 Sale Number") that can be sold in an orderly manner in such
offering within a price range acceptable to the Initiating Holder, the Company
shall include in such registration:

                           (i) all Registrable Securities requested to be
included in such registration by Holders of Registrable Securities; provided,
however, that, if the number of such Registrable Securities exceeds the Section
2.1 Sale Number, the number of such Registrable Securities (not to exceed the
Section 2.1 Sale Number) to be included in such registration shall be allocated
on a pro rata basis among all Holders requesting that Registrable Securities be
included in such registration, based on the number of Registrable Securities
then owned by each Holder requesting inclusion in relation to the number of
Registrable Securities owned by all Holders requesting inclusion;

                           (ii) to the extent that the number of Registrable
Securities to be included by all Holders pursuant to clause (i) of this Section
2.3(a) is less than the Section 2.1 Sale Number, securities that the Company
proposes to register; and

                           (iii) to the extent that the number of Registrable
Securities to be included by all Holders and the number of securities to be
included by the Company is less than the Section 2.1 Sale Number, any other
securities that the holders thereof propose to register pursuant to the exercise
of Additional Piggyback Rights.

                  If, as a result of the proration provisions of this Section
2.3(a), any Holder shall not be entitled to include all Registrable Securities
in a registration that such Holder has requested be included, such Holder may
elect to withdraw his request to include Registrable Securities in such
registration or may reduce the number requested to be included; provided,
however, that (x) such request must be made in writing prior to the earlier of
the execution of the underwriting agreement or the execution of the custody
agreement with respect to such registration and (y) such withdrawal shall be
irrevocable and, after making such withdrawal, a Holder shall no longer have any
right to include Registrable Securities in the registration as to which such
withdrawal was made.


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                  (b) If any registration pursuant to Section 2.2 involves an
underwritten offering and the Manager shall advise the Company that, in its
view, the number of securities requested to be included in such registration
exceeds the number (the "Section 2.2 Sale Number") that can be sold in an
orderly manner in such registration within a price range acceptable to the
Company, the Company shall include in such registration:

                           (i) all Common Stock or securities convertible into,
or exchangeable or exercisable for, Common Stock that the Company proposes to
register for its own account (the "Company Securities");

                           (ii) to the extent that the number of Company
Securities is less than the Section 2.2 Sale Number, the remaining shares to be
included in such registration shall be allocated on a pro rata basis among all
Holders of Registrable Securities requesting that Registrable Securities be
included in such registration, based on the number of Registrable Securities
then owned by each Holder requesting inclusion in relation to the number of
Registrable Securities owned by all Holders requesting inclusion; and

                          (iii) to the extent the number of Company Securities
plus the number of Registrable Securities requested to be included by all
Holders is less than the Section 2.2 Sale Number, any other securities that the
holders thereof propose to register pursuant to the exercise of Additional
Piggyback Rights.

         2.4.     Registration Procedures.

         If and whenever the Company is required by the provisions of this
Agreement to use its best efforts to effect or cause the registration of any
Registrable Securities under the Securities Act as provided in this Agreement,
the Company shall, as expeditiously as possible:

                  (a) prepare and file with the SEC a registration statement on
an appropriate registration form of the SEC for the disposition of such
Registrable Securities in accordance with the intended method of disposition
thereof, which form (i) shall be selected by the Company and (ii) shall, in the
case of a shelf registration, be available for the sale of the Registrable
Securities by the selling Holders thereof and such registration statement shall
comply as to form in all material respects with the requirements of the
applicable form and include all financial statements required by the SEC to be
filed therewith, and the Company shall use its best efforts to cause such
registration statement to become and remain effective (provided, however, that
before filing a registration statement or prospectus or any amendments or
supplements thereto, or comparable statements under securities or blue sky laws
of any jurisdiction, the Company will furnish to one counsel for the Holders
participating in the planned offering (selected by the


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Initiating Holder, in the case of a registration pursuant to Section 2.1, and
selected by the Major Holder, in the case of a registration pursuant to Section
2.2) and the underwriters, if any, copies of all such documents proposed to be
filed (including all exhibits thereto), which documents will be subject to the
reasonable review and reasonable comment of such counsel, and the Company shall
not file any registration statement or amendment thereto or any prospectus or
supplement thereto to which the Holders of a majority of the Registrable
Securities covered by such registration statement or the underwriters, if any,
shall reasonably object in writing);

                  (b) prepare and file with the SEC such amendments and
supplements to such registration statement and the prospectus used in connection
therewith as may be necessary to keep such registration statement effective for
such period (which shall not be required to exceed 180 days in the case of a
registration pursuant to Section 2.1 or 120 days in the case of a registration
pursuant to Section 2.2) as any seller of Registrable Securities pursuant to
such registration statement shall request and to comply with the provisions of
the Securities Act with respect to the sale or other disposition of all
Registrable Securities covered by such registration statement in accordance with
the intended methods of disposition by the seller or sellers thereof set forth
in such registration statement;

                  (c) furnish, without charge, to each seller of such
Registrable Securities and each underwriter, if any, of the securities covered
by such registration statement such number of copies of such registration
statement, each amendment and supplement thereto (in each case including all
exhibits), and the prospectus included in such registration statement (including
each preliminary prospectus) in conformity with the requirements of the
Securities Act, and other documents, as such seller and underwriter may
reasonably request in order to facilitate the public sale or other disposition
of the Registrable Securities owned by such seller (the Company hereby
consenting to the use in accordance with all applicable law of each such
registration statement (or amendment or post-effective amendment thereto) and
each such prospectus (or preliminary prospectus or supplement thereto) by each
such seller of Registrable Securities and the underwriters, if any, in
connection with the offering and sale of the Registrable Securities covered by
such registration statement or prospectus);

                  (d) use its best efforts to register or qualify the
Registrable Securities covered by such registration statement under such other
securities or "blue sky" laws of such jurisdictions as any sellers of
Registrable Securities or any managing underwriter, if any, shall reasonably
request, and do any and all other acts and things which may be reasonably
necessary or advisable to enable such sellers or underwriter, if any, to
consummate the disposition of the Registrable Securities in such jurisdictions,
except that in no event shall the Company be required to qualify to do business
as a foreign corporation in any jurisdiction where it would not, but for the
requirements of this


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paragraph (d), be required to be so qualified, to subject itself to taxation in
any such jurisdiction or to consent to general service of process in any such
jurisdiction;

                  (e) promptly notify each Holder selling Registrable Securities
covered by such registration statement and each managing underwriter, if any:
(i) when the registration statement, any pre-effective amendment, the prospectus
or any prospectus supplement related thereto or post-effective amendment to the
registration statement has been filed and, with respect to the registration
statement or any post-effective amendment, when the same has become effective;
(ii) of any request by the SEC or state securities authority for amendments or
supplements to the registration statement or the prospectus related thereto or
for additional information; (iii) of the issuance by the SEC of any stop order
suspending the effectiveness of the registration statement or the initiation of
any proceedings for that purpose; (iv) of the receipt by the Company of any
notification with respect to the suspension of the qualification of any
Registrable Securities for sale under the securities or blue sky laws of any
jurisdiction or the initiation of any proceeding for such purpose; (v) of the
existence of any fact of which the Company becomes aware which results in the
registration statement, the prospectus related thereto or any document
incorporated therein by reference containing an untrue statement of a material
fact or omitting to state a material fact required to be stated therein or
necessary to make any statement therein not misleading; and (vi) if at any time
the representations and warranties contemplated by any underwriting agreement,
securities sale agreement, or other similar agreement, relating to the offering
shall cease to be true and correct in all material respects; and, if the
notification relates to an event described in clause (v), the Company shall
promptly prepare and furnish to each such seller and each underwriter, if any, a
reasonable number of copies of a prospectus supplemented or amended so that, as
thereafter delivered to the purchasers of such Registrable Securities, such
prospectus shall not include 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 the light of the circumstances under which they were made
not misleading;

                  (f) comply with all applicable rules and regulations of the
SEC, and make generally available to its security holders, as soon as reasonably
practicable after the effective date of the registration statement (and in any
event within 17 months thereafter), an earnings statement (which need not be
audited) covering the period of at least twelve consecutive months beginning
with the first day of the Company's first calendar quarter after the effective
date of the registration statement, which earnings statement shall satisfy the
provisions of Section 11(a) of the Securities Act and Rule 158 thereunder;

                  (g) (i) cause all such Registrable Securities covered by such
registration statement to be listed on the principal securities exchange on
which similar securities issued by the Company are then listed (if any), if the
listing of such Registrable Securities


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is then permitted under the rules of such exchange, or (ii) if no similar
securities are then so listed, to either cause all such Registrable Securities
to be listed on a national securities exchange or to secure designation of all
such Registrable Securities as a Nasdaq National Market "national market system
security" within the meaning of Rule 11Aa2-1 of the Exchange Act or, failing
that, secure Nasdaq National Market authorization for such shares and, without
limiting the generality of the foregoing, take all actions that may be required
by the Company as the issuer of such Registrable Securities in order to
facilitate the managing underwriter's arranging for the registration of at least
two market makers as such with respect to such shares with the National
Association of Securities Dealers, Inc. (the "NASD");

                  (h) provide and cause to be maintained a transfer agent and
registrar for all such Registrable Securities covered by such registration
statement not later than the effective date of such registration statement;

                  (i) enter into such customary agreements (including, if
applicable, an underwriting agreement) and take such other actions as the
Holders of a majority of the Registrable Securities or the Major Holder
participating in such offering shall reasonably request in order to expedite or
facilitate the disposition of such Registrable Securities. The Holders of the
Registrable Securities which are to be distributed by such underwriters shall be
parties to such underwriting agreement and may, at their option, require that
the Company make to and for the benefit of such Holders the representations,
warranties and covenants of the Company which are being made to and for the
benefit of such underwriters and which are of the type customarily provided to
institutional investors in secondary offerings;

                  (j) use its best efforts to obtain an opinion from the
Company's counsel and a "cold comfort" letter from the Company's independent
public accountants in customary form and covering such matters as are
customarily covered by such opinions and "cold comfort" letters delivered to
underwriters in underwritten public offerings, which opinion and letter shall be
reasonably satisfactory to the underwriter, if any, and to the Major Holder
participating in such offering, and furnish to each Holder participating in the
offering and to each underwriter, if any, a copy of such opinion and letter
addressed to such Holder or underwriter;

                  (k) deliver promptly to each Holder participating in the
offering and each underwriter, if any, copies of all correspondence between the
SEC and the Company, its counsel or auditors and all memoranda relating to
discussions with the SEC or its staff with respect to the registration
statement, other than those portions of any such memoranda which contain
information subject to attorney-client privilege with respect to the Company,
and, upon receipt of such confidentiality agreements as the Company may
reasonably request, make reasonably available for inspection by any seller of
such


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Registrable Securities covered by such registration statement, by any
underwriter, if any, participating in any disposition to be effected pursuant to
such registration statement and by any attorney, accountant or other agent
retained by any such seller or any such underwriter, all pertinent financial and
other records, pertinent corporate documents and properties of the Company, and
cause all of the Company's officers, directors and employees to supply all
information reasonably requested by any such seller, underwriter, attorney,
accountant or agent in connection with such registration statement;

                  (l) use its best efforts to obtain the withdrawal of any order
suspending the effectiveness of the registration statement;

                  (m) provide a CUSIP number for all Registrable Securities, not
later than the effective date of the registration statement;

                  (n) make reasonably available its employees and personnel and
otherwise provide reasonable assistance to the underwriters (taking into account
the needs of the Company's businesses and the requirements of the marketing
process) in the marketing of Registrable Securities in any underwritten
offering;

                  (o) promptly prior to the filing of any document which is to
be incorporated by reference into the registration statement or the prospectus
(after the initial filing of such registration statement) provide copies of such
document to counsel for the selling holders of Registrable Securities and to
each managing underwriter, if any, and make the Company's representatives
reasonably available for discussion of such document and make such changes in
such document concerning the selling holders prior to the filing thereof as
counsel for such selling holders or underwriters may reasonably request;

                  (p) furnish to the Major Holder participating in the offering
and the managing underwriter, without charge, at least one signed copy, and to
each other Holder participating in the offering, without charge, at least one
photocopy of a signed copy, of the registration statement and any post-effective
amendments thereto, including financial statements and schedules, all documents
incorporated therein by reference and all exhibits (including those incorporated
by reference);

                  (q) cooperate with the selling Holders of Registrable
Securities and the managing underwriter, if any, to facilitate the timely
preparation and delivery of certificates not bearing any restrictive legends
representing the Registrable Securities to be sold, and cause such Registrable
Securities to be issued in such denominations and registered in such names in
accordance with the underwriting agreement prior to any sale of Registrable
Securities to the underwriters or, if not an underwritten offering, in
accordance with the instructions of the selling Holders of Registrable
Securities at least three business days prior to any sale of Registrable
Securities and instruct any transfer


                                      -12-
<PAGE>   14

agent and registrar of Registrable Securities to release any stop transfer
orders in respect thereof; and

                  (r) take all such other commercially reasonable actions as are
necessary or advisable in order to expedite or facilitate the disposition of
such Registrable Securities.

                  (s) take no direct or indirect action prohibited by Regulation
M under the Exchange Act; provided, however, that to the extent that any
prohibition is applicable to the Company, the Company will take such action as
is necessary to make any such prohibition inapplicable.

                  The Company may require as a condition precedent to the
Company's obligations under this Section 2.4 that each seller of Registrable
Securities as to which any registration is being effected furnish the Company
such information regarding such seller and the distribution of such securities
as the Company may from time to time reasonably request provided that such
information is necessary for the Company to consummate such registration and
shall be used only in connection with such registration.

                  Each Holder of Registrable Securities agrees that upon receipt
of any notice from the Company of the happening of any event of the kind
described in clause (v) of paragraph (e) of this Section 2.4, such Holder will
discontinue such Holder's disposition of Registrable Securities pursuant to the
registration statement covering such Registrable Securities until such Holder's
receipt of the copies of the supplemented or amended prospectus contemplated by
paragraph (e) of this Section 2.4 and, if so directed by the Company, will
deliver to the Company (at the Company's expense) all copies, other than
permanent file copies, then in such Holder's possession of the prospectus
covering such Registrable Securities that was in effect at the time of receipt
of such notice. In the event the Company shall give any such notice, the
applicable period mentioned in paragraph (b) of this Section 2.4 shall be
extended by the number of days during such period from and including the date of
the giving of such notice to and including the date when each seller of any
Registrable Securities covered by such registration statement shall have
received the copies of the supplemented or amended prospectus contemplated by
paragraph (e) of this Section 2.4.

                  If any such registration statement or comparable statement
under "blue sky" laws refers to any Holder by name or otherwise as the Holder of
any securities of the Company, then such Holder shall have the right to require
(i) the insertion therein of language, in form and substance reasonably
satisfactory to such Holder and the Company, to the effect that the holding by
such Holder of such securities is not to be construed as a recommendation by
such Holder of the investment quality of the Company's securities covered
thereby and that such holding does not imply that such Holder will assist in


                                      -13-
<PAGE>   15

meeting any future financial requirements of the Company, or (ii) in the event
that such reference to such Holder by name or otherwise is not in the judgment
of the Company, as advised by counsel, required by the Securities Act or any
similar federal statute or any state "blue sky" or securities law then in force,
the deletion of the reference to such Holder.

         2.5.     Registration Expenses.

                  (a) "Expenses" shall mean any and all fees and expenses
incident to the Company's performance of or compliance with this Article 2,
including, without limitation: (i) SEC, stock exchange or NASD registration and
filing fees and all listing fees and fees with respect to the inclusion of
securities in Nasdaq National Market, (ii) fees and expenses of compliance with
state securities or "blue sky" laws and in connection with the preparation of a
"blue sky" survey, including without limitation, reasonable fees and expenses of
blue sky counsel, (iii) printing and copying expenses, (iv) messenger and
delivery expenses, (v) expenses incurred in connection with any road show, (vi)
fees and disbursements of counsel for the Company, (vii) with respect to each
registration, the fees and disbursements of one counsel for the selling
Holder(s) (selected by the Initiating Holder, in the case of a registration
pursuant to Section 2.1, and selected by the Major Holder, in the case of a
registration pursuant to Section 2.2), (viii) fees and disbursements of all
independent public accountants (including the expenses of any audit and/or "cold
comfort" letter) and fees and expenses of other persons, including special
experts, retained by the Company, (ix) fees and expenses payable to a Qualified
Independent Underwriter (as such term is defined in Schedule E to the By-Laws of
the NASD) and (x) any other fees and disbursements of underwriters, if any,
customarily paid by issuers or sellers of securities (collectively, "Expenses").

                  (b) The Company shall pay all Expenses with respect to any
Demand Registration pursuant to Section 2.1 and any piggyback registrations
pursuant to Section 2.2.

                  (c) Notwithstanding the foregoing, (x) the provisions of this
Section 2.5 shall be deemed amended to the extent necessary to cause these
expense provisions to comply with "blue sky" laws of each state in which the
offering is made and (y) in connection with any registration hereunder, each
Holder of Registrable Securities being registered shall pay all underwriting
discounts and commissions and any transfer taxes, if any, attributable to the
sale of such Registrable Securities, pro rata with respect to payments of
discounts and commissions in accordance with the number of shares sold in the
offering by such Holder, and (z) the Company shall, in the case of all
registrations under this Article 2, be responsible for all its internal expenses
(including, without limitation, all salaries and expenses of its officers and
employees performing legal or accounting duties).


                                      -14-
<PAGE>   16

         2.6.     Certain Limitations on Registration Rights.

                  In the case of any registration under Section 2.1 pursuant to
an underwritten offering, or in the case of a registration under Section 2.2 if
the Company has determined to enter into an underwriting agreement in connection
therewith, all securities to be included in such registration shall be subject
to an underwriting agreement and no person may participate in such registration
unless such person agrees to sell such person's securities on the basis provided
therein and completes and executes all reasonable questionnaires, and other
documents (including custody agreements and powers of attorney) which must be
executed in connection therewith, and provides such other information to the
Company or the underwriter as may be necessary to register such Person's
securities.

         2.7.     Limitations on Sale or Distribution of Other Securities.

                  (a) Each Holder of Registrable Securities agrees that, (i) to
the extent requested in writing by a managing underwriter, if any, of an IPO or
any registration effected pursuant to Section 2.1, not to sell, transfer or
otherwise dispose of, including any sale pursuant to Rule 144 under the
Securities Act, any Common Stock, or any other equity security of the Company or
any security convertible into or exchangeable or exercisable for any equity
security of the Company (other than as part of such underwritten public
offering) during the time period reasonably requested by the managing
underwriter, not to exceed 180 days (and the Company hereby also so agrees
(except that the Company may effect any sale or distribution of any such
securities pursuant to a registration on Form S-4 (if reasonably acceptable to
such managing underwriter) or Form S-8, or any successor or similar form which
is then in effect or upon the conversion, exchange or exercise of any then
outstanding Common Stock Equivalent) to use its reasonable best efforts to cause
each holder of any equity security or any security convertible into or
exchangeable or exercisable for any equity security of the Company purchased
from the Company at any time other than in a public offering so to agree), and
(ii) to the extent requested in writing by a managing underwriter of any
underwritten public offering effected by the Company for its own account (other
than the IPO) it will not sell any Common Stock (other than as part of such
underwritten public offering) during the time period reasonably requested by the
managing underwriter, which period shall not exceed 90 days.

                  (b) The Company hereby agrees that, if it shall previously
have received a request for registration (other than a shelf registration)
pursuant to Section 2.1 or 2.2, and if such previous registration shall not have
been withdrawn or abandoned, the Company shall not sell, transfer, or otherwise
dispose of, any Common Stock, or any other equity security of the Company or any
security convertible into or exchangeable or exercisable for any equity security
of the Company (other than as part of such


                                      -15-
<PAGE>   17

underwritten public offering, a registration on Form S-4 or Form S-8 or any
successor or similar form which is then in effect or upon the conversion,
exchange or exercise of any then outstanding Common Stock Equivalent), until a
period of 90 days shall have elapsed from the effective date of such previous
registration; and the Company shall so provide in any registration rights
agreements hereafter entered into with respect to any of its securities.

         2.8.     No Required Sale.

         Nothing in this Agreement shall be deemed to create an independent
obligation on the part of any Holder to sell any Registrable Securities pursuant
to any effective registration statement.

         2.9.     Indemnification.

                  (a) In the event of any registration of any securities of the
Company under the Securities Act pursuant to this Article 2, the Company will,
and hereby does, indemnify and hold harmless, to the fullest extent permitted by
law, each Holder of Registrable Securities, its directors, officers,
fiduciaries, employees and stockholders or general and limited partners (and the
directors, officers, employees and stockholders thereof), each other Person who
participates as an underwriter or a Qualified Independent Underwriter, if any,
in the offering or sale of such securities, each officer, director, employee,
stockholder, fiduciary, managing director, agent, affiliates, consultants,
representatives, successors, assigns or partner of such underwriter or Qualified
Independent Underwriter, and each other Person, if any, who controls such seller
or any such underwriter within the meaning of the Securities Act, against any
and all losses, claims, damages or liabilities, joint or several, actions or
proceedings (whether commenced or threatened) and expenses (including reasonable
fees of counsel and any amounts paid in any settlement effected with the
Company's consent, which consent shall not be unreasonably withheld or delayed)
to which each such indemnified party may become subject under the Securities Act
or otherwise in respect thereof (collectively, "Claims"), insofar as such Claims
arise out of or are based upon (i) any untrue statement or alleged untrue
statement of a material fact contained in any registration statement under which
such securities were registered under the Securities Act or the omission or
alleged omission to state therein a material fact required to be stated therein
or necessary to make the statements therein not misleading, (ii) any untrue
statement or alleged untrue statement of a material fact contained in any
preliminary, final or summary prospectus or any amendment or supplement thereto,
together with the documents incorporated by reference therein, or the omission
or alleged omission to state therein a material fact required to be stated
therein or necessary in order to make the statements therein, in the light of
the circumstances under which they were made, not misleading, or (iii) any
violation by the Company of any federal, state or common law rule or regulation


                                      -16-
<PAGE>   18

applicable to the Company and relating to action required of or inaction by the
Company in connection with any such registration, and the Company will reimburse
any such indemnified party for any legal or other expenses reasonably incurred
by such indemnified party in connection with investigating or defending any such
Claim as such expenses are incurred; provided, however, that the Company shall
not be liable to any such indemnified party in any such case to the extent such
Claim arises out of or is based upon any untrue statement or alleged untrue
statement of a material fact or omission or alleged omission of a material fact
made in such registration statement or amendment thereof or supplement thereto
or in any such prospectus or any preliminary, final or summary prospectus in
reliance upon and in conformity with written information furnished to the
Company by or on behalf of such indemnified party specifically for use therein.
Such indemnity and reimbursement of expenses shall remain in full force and
effect regardless of any investigation made by as on behalf of such indemnified
party and shall survive the transfer of such securities by such seller.

                  (b) Each Holder of Registrable Securities that are included in
the securities as to which any registration under Section 2.1 or 2.2 is being
effected (and, if the Company requires as a condition to including any
Registrable Securities in any registration statement filed in accordance with
Section 2.1 or 2.2, any underwriter and Qualified Independent Underwriter, if
any) shall, severally and not jointly, indemnify and hold harmless (in the same
manner and to the same extent as set forth in paragraph (a) of this Section 2.9)
to the extent permitted by law the Company, its officers and directors, each
Person controlling the Company within the meaning of the Securities Act and all
other prospective sellers and their respective directors, officers, fiduciaries,
managing directors, employees, agents, affiliates, consultants, representatives,
successors, assigns, general and limited partners, stockholders and respective
controlling Persons with respect to any untrue statement or alleged untrue
statement of any material fact in, or omission or alleged omission of any
material fact from, such registration statement, any preliminary, final or
summary prospectus contained therein, or any amendment or supplement thereto, if
such statement or alleged statement or omission or alleged omission was made in
reliance upon and in conformity with written information furnished to the
Company or its representatives by or on behalf of such Holder or underwriter or
Qualified Independent Underwriter, if any, specifically for use therein and
reimburse such indemnified party for any legal or other expenses reasonably
incurred in connection with investigating or defending any such Claim as such
expenses are incurred; provided, however, that the aggregate amount which any
such Holder shall be required to pay pursuant to this Section 2.9(b) and
Sections 2.9(c) and (e) shall in no case be greater than the amount of the net
proceeds received by such person upon the sale of the Registrable Securities
pursuant to the registration statement giving rise to such claim. Such indemnity
and reimbursement of expenses shall remain in full force and effect regardless
of any investigation made by or on behalf of such indemnified party and shall
survive the transfer of such securities by such Holder.


                                      -17-
<PAGE>   19

                  (c) Indemnification similar to that specified in the preceding
paragraphs (a) and (b) of this Section 2.9 (with appropriate modifications)
shall be given by the Company and each seller of Registrable Securities with
respect to any required registration or other qualification of securities under
any state securities and "blue sky" laws.

                  (d) Any person entitled to indemnification under this
Agreement shall notify promptly the indemnifying party in writing of the
commencement of any action or proceeding with respect to which a claim for
indemnification may be made pursuant to this Section 2.9, but the failure of any
indemnified party to provide such notice shall not relieve the indemnifying
party of its obligations under the preceding paragraphs of this Section 2.9,
except to the extent the indemnifying party is materially prejudiced thereby and
shall not relieve the indemnifying party from any liability which it may have to
any indemnified party otherwise than under this Article 2. In case any action or
proceeding is brought against an indemnified party and it shall notify the
indemnifying party of the commencement thereof, the indemnifying party shall be
entitled to participate therein and, unless in the reasonable opinion of outside
counsel to the indemnified party a conflict of interest between such indemnified
and indemnifying parties may exist in respect of such claim, to assume the
defense thereof jointly with any other indemnifying party similarly notified, to
the extent that it chooses, with counsel reasonably satisfactory to such
indemnified party, and after notice from the indemnifying party to such
indemnified party that it so chooses, the indemnifying party shall not be liable
to such indemnified party for any legal or other expenses subsequently incurred
by such indemnified party in connection with the defense thereof other than
reasonable costs of investigation; provided, however, that (i) if the
indemnifying party fails to take reasonable steps necessary to defend diligently
the action or proceeding within 20 days after receiving notice from such
indemnified party that the indemnified party believes it has failed to do so; or
(ii) if such indemnified party who is a defendant in any action or proceeding
which is also brought against the indemnifying party reasonably shall have
concluded that there may be one or more legal defenses available to such
indemnified party which are not available to the indemnifying party; or (iii) if
representation of both parties by the same counsel is otherwise inappropriate
under applicable standards of professional conduct, then, in any such case, the
indemnified party shall have the right to assume or continue its own defense as
set forth above (but with no more than one firm of counsel for all indemnified
parties in each jurisdiction, except to the extent any indemnified party or
parties reasonably shall have concluded that there may be legal defenses
available to such party or parties which are not available to the other
indemnified parties or to the extent representation of all indemnified parties
by the same counsel is otherwise inappropriate under applicable standards of
professional conduct) and the indemnifying party shall be liable for any
expenses therefor. No indemnifying party shall, without the written consent of
the indemnified party, effect the settlement or compromise of, or consent to the
entry of any judgment with respect to, any pending or


                                      -18-
<PAGE>   20

threatened action or claim in respect of which indemnification or contribution
may be sought hereunder (whether or not the indemnified party is an actual or
potential party to such action or claim) unless such settlement, compromise or
judgment (A) includes an unconditional release of the indemnified party from all
liability arising out of such action or claim and (B) does not include a
statement as to or an admission of fault, culpability or a failure to act, by or
on behalf of any indemnified party.

                  (e) If for any reason the foregoing indemnity is unavailable
or is insufficient to hold harmless an indemnified party under Sections 2.9(a),
(b) or (c), then each indemnifying party shall contribute to the amount paid or
payable by such indemnified party as a result of any Claim in such proportion as
is appropriate to reflect the relative fault of the indemnifying party, on the
one hand, and the indemnified party, on the other hand, with respect to such
offering of securities. The relative fault 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 indemnifying party or the indemnified party and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such untrue statement or omission. If, however, the
allocation provided in the second preceding sentence is not permitted by
applicable law, then each indemnifying party shall contribute to the amount paid
or payable by such indemnified party in such proportion as is appropriate to
reflect not only such relative faults but also the relative benefits of the
indemnifying party and the indemnified party as well as any other relevant
equitable considerations. The parties hereto agree that it would not be just and
equitable if contributions pursuant to this Section 2.9(e) were to be determined
by pro rata allocation or by any other method of allocation which does not take
account of the equitable considerations referred to in the preceding sentences
of this Section 2.9(e). The amount paid or payable in respect of any Claim shall
be deemed to include any legal or other expenses reasonably incurred by such
indemnified party in connection with investigating or defending any such Claim.
No person guilty of fraudulent misrepresentation (within the meaning of Section
11(f) of the Securities Act) shall be entitled to contribution from any person
who was not guilty of such fraudulent misrepresentation. Notwithstanding
anything in this section 2.9(e) to the contrary, no indemnifying party (other
than the Company) shall be required pursuant to this section 2.9(e) to
contribute any amount in excess of the net proceeds received by such
indemnifying party from the sale of Registrable Securities in the offering to
which the losses, claims, damages or liabilities of the indemnified parties
relate, less the amount of any indemnification payment made by such indemnifying
party pursuant to Sections 2.9(b) and (c).

                  (f) The indemnity agreements contained herein shall be in
addition to any other rights to indemnification or contribution which any
indemnified party may have pursuant to law or contract and shall remain
operative and in full force and effect


                                      -19-
<PAGE>   21

regardless of any investigation made or omitted by or on behalf of any
indemnified party and shall survive the transfer of the Registrable Securities
by any such party.

                  (g) The indemnification and contribution required by this
Section 2.9 shall be made by periodic payments of the amount thereof during the
course of the investigation or defense, as and when bills are received or
expense, loss, damage or liability is incurred.

         2.10     Blackout Periods for Shelf Registrations.

                  (a) At any time when a shelf registration effected pursuant to
Section 2 relating to the Registrable Securities is effective, upon written
notice from the Company to the Holders participating in the registration that
the Company determines in the good faith judgment of the Board of Directors of
the Company that such Holders' sale of the Registrable Securities pursuant to
the shelf registration would require disclosure of material information which
the Company has a bona fide business purpose for preserving as confidential and
the disclosure of which would have a material adverse effect on the Company or
the Company is unable to comply with SEC requirements (an "Information
Blackout"), such Holders shall suspend sales of the Registrable Securities
pursuant to such shelf registration until the earlier of (i) the date upon which
such material information is disclosed to the public or ceases to be material,
(ii) 90 days after the Board of Directors of the Company makes such good faith
determination or (iii) such time as the Company notifies Holders that sales
pursuant to such shelf registration may be resumed (the number of days from such
suspension of sales of the Holders until the day when such sales may be resumed
hereunder is hereinafter called a "Sales Blackout Period").

                  (b) If there is an Information Blackout and the Holders do not
notify the Company in writing of their desire to cancel such shelf registration,
the period set forth in Section 2.4(b) shall be extended for a number of days
equal to the number of days in the Sales Blackout Period.

3.       Underwritten Offerings.

         3.1. Requested Underwritten Offerings. If requested by the underwriters
for any underwritten offering by the Holders pursuant to a registration
requested under Section 2.1, the Company shall enter into a customary
underwriting agreement with the underwriters. Such underwriting agreement shall
be satisfactory in form and substance to the Initiating Holder and shall contain
such representations and warranties by, and such other agreements on the part
of, the Company and such other terms as are generally prevailing in agreements
of that type, including, without limitation, indemnities and contribution
agreements on substantially the same terms as those contained herein. Any Holder
participating in the offering shall be a party to such underwriting agreement
and may, at its option, require that any or all of the representations and
warranties by, and the


                                      -20-
<PAGE>   22

other agreements on the part of, the Company to and for the benefit of such
underwriters shall also be made to and for the benefit of such Holder and that
any or all of the conditions precedent to the obligations of such underwriters
under such underwriting agreement be conditions precedent to the obligations of
such Holder; provided, however, that the Company shall not be required to make
any representations or warranties with respect to written information
specifically provided by a selling Holder for inclusion in the registration
statement. Such underwriting agreement shall also contain such representations
and warranties by the participating Holders with respect to title and ownership
of shares as are customary in agreements of that type.

         3.2. Piggyback Underwritten Offerings. In the case of a registration
pursuant to Section 2.2 hereof, if the Company shall have determined to enter
into an underwriting agreement in connection therewith, all of the Holders'
Registrable Securities to be included in such registration shall be subject to
such underwriting agreement. Any Holder participating in such registration may,
at its option, require that any or all of the representations and warranties by,
and the other agreements on the part of, the Company to and for the benefit of
such underwriters shall also be made to and for the benefit of such Holder and
that any or all of the conditions precedent to the obligations of such
underwriters under such underwriting agreement be conditions precedent to the
obligations of such Holder. Such underwriting agreement shall also contain such
representations and warranties by the participating Holders as are customary in
agreements of that type, on substantially the same terms as those contained
herein.

4.       General.

         4.1. Adjustments Affecting Registrable Securities. The Company agrees
that it shall not effect or permit to occur any combination or subdivision of
shares which would adversely affect the ability of the Holder of any Registrable
Securities to include such Registrable Securities in any registration
contemplated by this Agreement or the marketability of such Registrable
Securities in any such registration. The Company agrees that it will take all
reasonable steps necessary to effect a subdivision of shares if in the
reasonable judgment of (a) the Initiating Holder of a Demand Registration
Request or (b) the managing underwriter for the offering in respect of such
Demand Registration Request, such subdivision would enhance the marketability of
the Registrable Securities. Each Holder agrees to vote all of its shares of
capital stock in a manner, and to take all other actions necessary, to permit
the Company to carry out the intent of the preceding sentence including, without
limitation, voting in favor of an amendment to the Company's Certificate of
Incorporation in order to increase the number of authorized shares of capital
stock of the Company.

         4.2. Rule 144. If the Company shall have filed a registration statement
pursuant to the requirements of Section 12 of the Exchange Act or a registration
statement pursuant


                                      -21-
<PAGE>   23

to the requirements of the Securities Act in respect of the Common Stock or
securities of the Company convertible into or exchangeable or exercisable for
Common Stock, the Company covenants that (i) so long as it remains subject to
the reporting provisions of the Exchange Act, it will timely file the reports
required to be filed by it under the Securities Act or the Exchange Act
(including, but not limited to, the reports under Sections 13 and 15(d) of the
Exchange Act referred to in subparagraph (c)(1) of Rule 144 under the Securities
Act), and (ii) will take such further action as any Holder of Registrable
Securities 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 (A) Rule
144 under the Securities Act, as such Rule may be amended from time to time, or
(B) any similar rule or regulation hereafter adopted by the SEC. Upon the
request of any Holder of Registrable Securities, the Company will deliver to
such Holder a written statement as to whether it has complied with such
requirements.

         4.3. Nominees for Beneficial Owners. If Registrable Securities are held
by a nominee for the beneficial owner thereof, the beneficial owner thereof may,
at its option, be treated as the Holder of such Registrable Securities for
purposes of any request or other action by any Holder or Holders of Registrable
Securities pursuant to this Agreement (or any determination of any number or
percentage of shares constituting Registrable Securities held by any Holder or
Holders of Registrable Securities contemplated by this Agreement), provided that
the Company shall have received assurances reasonably satisfactory to it of such
beneficial ownership.

         4.4 Amendments and Waivers. The terms and provisions of this Agreement
may be modified or amended, or any of the provisions hereof waived, temporarily
or permanently, pursuant to the written consent of the Company and Cabot.

         4.5. Notices. Except as otherwise provided in this Agreement, all
notices, requests, consents and other communications hereunder to any party
shall be delivered in person or by telecopy (with a confirmatory copy sent by a
different means within three business days of such notice), nationally
recognized overnight courier or first class registered or certified mail, return
receipt requested, postage prepaid, addressed to such party at the address set
forth below or such other address as may hereafter be designated in writing by
such party to the other parties:

                           (i)      if to the Company, to:

                                    Cabot Microelectronics Corporation
                                    870 North Commons Drive
                                    Aurora, IL  60504


                                      -22-
<PAGE>   24

                                    Telecopy:  (630) 375-5593
                                    Attention: President



                           (ii)     if to Cabot, to:

                                    Cabot Corporation
                                    75 State Street
                                    Boston, MA  02109
                                    Telecopy:  (617) 342-6281
                                    Attention:  Chief Financial Officer

                                    with copies to:

                                    Fried, Frank, Harris, Shriver & Jacobson
                                    One New York Plaza
                                    New York, New York  10004
                                    Telecopy:  (212) 859-8589
                                    Attention: Thomas W. Christopher

All such notices, requests, consents and other communications shall be deemed to
have been given when received.

         4.6.     Miscellaneous.

                  (a) This Agreement shall be binding upon and inure to the
benefit of and be enforceable by the parties hereto and the respective
successors, personal representatives and assigns of the parties hereto, whether
so expressed or not. If any Person shall acquire Registrable Securities from any
Holder, in any manner, whether by operation of law or otherwise, such transferee
shall promptly notify the Company and such Registrable Securities acquired from
such Holder shall be held subject to all of the terms of this Agreement, and by
taking and holding such Registrable Securities such Person shall be entitled to
receive the benefits of and be conclusively deemed to have agreed to be bound by
and to perform all of the terms and provisions of this Agreement. If the Company
shall so request, any such successor or assign shall agree in writing to acquire
and hold the Registrable Securities acquired from such Holder subject to all of
the terms hereof. If any Holder shall acquire additional Registrable Securities,
such Registrable Securities shall be subject to all of the terms, and entitled
to all the benefits, of this Agreement.

                  (b) This Agreement (with the documents referred to herein or
delivered pursuant hereto) embodies the entire agreement and understanding
between the parties


                                      -23-
<PAGE>   25

hereto and supersedes all prior agreements and understandings relating to the
subject matter hereof.

                  (c) This Agreement shall be construed and enforced in
accordance with and governed by the laws of the State of New York without giving
effect to the conflicts of law principles thereof.

                  (d) The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof. All
section references are to this Agreement unless otherwise expressly provided.

                  (e) This Agreement may be executed in any number of
counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.

                  (f) Any term or provision of this Agreement which is invalid
or unenforceable in any jurisdiction shall, as to such jurisdiction, be
ineffective to the extent of such invalidity or unenforceability without
rendering invalid or unenforceable the remaining terms and provisions of this
Agreement or affecting the validity or enforceability of any of the terms or
provisions of this Agreement in any other jurisdiction.

                  (g) The parties hereto acknowledge that there would be no
adequate remedy at law if any party fails to perform any of its obligations
hereunder, and accordingly agree that each party, in addition to any other
remedy to which it may be entitled at law or in equity, shall be entitled to
injunctive relief, including specific performance, to enforce such obligations
without the posting of any bond, and, if any action should be brought in equity
to enforce any of the provisions of this Agreement, none of the parties hereto
shall raise the defense that there is an adequate remedy at law.

                  (h) Each party hereto shall do and perform or cause to be done
and performed all such further acts and things and shall execute and deliver all
such other agreements, certificates, instruments, and documents as any other
party hereto reasonably may request in order to carry out the intent and
accomplish the purposes of this Agreement and the consummation of the
transactions contemplated hereby.

         4.7. Prior Agreements. Each of the Holders and the Company hereby
agrees that any agreement previously entered into by it pursuant to which the
Company granted to it any registration rights shall be superseded by this
Agreement and each such agreement (and any rights such Holder has pursuant to
such agreement) shall be terminated, null and void and no longer in effect.


                                      -24-
<PAGE>   26

         4.8. No Inconsistent Agreements. The rights granted to the holders of
Registrable Securities hereunder do not in any way conflict with and are not
inconsistent with any other agreements to which the Company is a party or by
which it is bound. Without the prior written consent of Cabot, neither the
Company nor any Holder will, on or after the date of this Agreement, enter into
any agreement with respect to its securities which is inconsistent with the
rights granted in this Agreement or otherwise conflicts with the provisions
hereof, other than any lock-up agreement with the underwriters in connection
with any registered offering effected hereunder, pursuant to which the Company
shall agree not to register for sale, and the Company shall agree not to sell or
otherwise dispose of, Common Stock or any securities convertible into or
exercisable or exchangeable for Common Stock, for a specified period following
the registered offering. The Company further agrees that if any other
registration rights agreement entered into after the date of this Agreement with
respect to any of its securities contains terms which are more favorable to, or
less restrictive on, the other party thereto than the terms and conditions
contained in this Agreement are (insofar as they are applicable) to Cabot, then
the terms and conditions of this Agreement shall immediately be deemed to have
been amended without further action by the Company or any of the holders of
Registrable Securities so that Cabot shall be entitled to the benefit of any
such more favorable or less restrictive terms or conditions.

         4.9 Effective Time. This Agreement shall become effective upon the
closing of the Company's IPO.

                                      -25-
<PAGE>   27

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

                                            CABOT MICROELECTRONICS CORPORATION


                                            By:  /s/ Matthew Neville
                                                 ------------------------------
                                                 Name:  Matthew Neville
                                                 Title: President and
                                                        Chief Executive Officer



                                            CABOT CORPORATION


                                            By:  /s/ Samuel W. Bodman
                                                 ------------------------------
                                                 Name:  Samuel W. Bodman
                                                 Title: Chairman and
                                                        Chief Executive Officer


                                      -26-