<PAGE>


                                                                     EXHIBIT 1.1


                            IPG PHOTONICS CORPORATION

                             (Delaware corporation)

                             Shares of Common Stock

                          (Par Value $0.0001 Per Share)


                             UNDERWRITING AGREEMENT

                                                                         , 2006

MERRILL LYNCH & CO.
Merrill Lynch, Pierce, Fenner & Smith Incorporated
Lehman Brothers Inc.
as Representatives of the several Underwriters

c/o Merrill Lynch & Co.
Merrill Lynch, Pierce, Fenner & Smith Incorporated
4 World Financial Center
New York, New York  10080

c/o Lehman Brothers Inc.
745 Seventh Avenue
New York, New York  10019

Ladies and Gentlemen:

         IPG Photonics Corporation, a Delaware corporation (the "Company"), and
the persons listed in Schedule B hereto (the "Selling Stockholders"), confirm
their respective agreements with Merrill Lynch & Co., Merrill Lynch, Pierce,
Fenner & Smith Incorporated ("Merrill Lynch"), Lehman Brothers Inc. ("Lehman
Brothers") and each of the other Underwriters named in Schedule A hereto
(collectively, the "Underwriters," which term shall also include any underwriter
substituted as hereinafter provided in Section 10 hereof), for whom Merrill
Lynch and Lehman Brothers are acting as representatives (in such capacity, the
"Representatives"), with respect to (i) the sale by the Company and the Selling
Stockholders, acting severally and not jointly, and the purchase by the
Underwriters, acting severally and not jointly, of the respective numbers of
shares of Common Stock, par value $0.0001 per share, of the Company ("Common
Stock") set forth in Schedules A and B hereto and (ii) the grant by certain of
the Selling Stockholders to the Underwriters, acting severally and not jointly,
of the option described in Section 2(b) hereof to purchase all or any part of o
additional shares of Common Stock to cover overallotments, if any, as set forth
in Schedule B. The aforesaid          shares of Common Stock (the "Initial
Securities") to be purchased by the Underwriters and all or any part of the
        shares of Common Stock subject to the option described in Section 2(b)
hereof (the "Option Securities") are hereinafter called, collectively, the
"Securities."

         The Company and the Selling Stockholders understand that the
Underwriters propose to make a public offering of the Securities as soon as the
Representatives deem advisable after this Agreement has been executed and
delivered.


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         The Company has filed with the Securities and Exchange Commission (the
"Commission") a registration statement on Form S-1 (No. 333-136521), including
the related preliminary prospectus or prospectuses, covering the registration of
the Securities under the Securities Act of 1933, as amended (the "1933 Act").
Promptly after execution and delivery of this Agreement, the Company will
prepare and file a prospectus in accordance with the provisions of Rule 430A
("Rule 430A") of the rules and regulations of the Commission under the 1933 Act
(the "1933 Act Regulations") and paragraph (b) of Rule 424 ("Rule 424(b)") of
the 1933 Act Regulations. The information included in such prospectus that was
omitted from such registration statement at the time it became effective but
that is deemed to be part of such registration statement at the time it became
effective pursuant to paragraph (b) of Rule 430A is referred to as "Rule 430A
Information." Each prospectus used before such registration statement became
effective, and any prospectus that omitted the Rule 430A Information, that was
used after such effectiveness and prior to the execution and delivery of this
Agreement, is herein called a "preliminary prospectus." Such registration
statement, including the amendments thereto, the exhibits and any schedules
thereto, at the time it became effective, and including the Rule 430A
Information, is herein called the "Registration Statement." Any registration
statement filed pursuant to Rule 462(b) of the 1933 Act Regulations is herein
referred to as the "Rule 462(b) Registration Statement," and after such filing
the term "Registration Statement" shall include the Rule 462(b) Registration
Statement. The final prospectus in the form first furnished to the Underwriters
for use in connection with the offering of the Securities is herein called the
"Prospectus." For purposes of this Agreement, all references to the Registration
Statement, any preliminary prospectus, the Prospectus or any amendment or
supplement to any of the foregoing shall be deemed to include the copy filed
with the Commission pursuant to its Electronic Data Gathering, Analysis and
Retrieval system ("EDGAR").

         SECTION 1. Representations and Warranties.

         (a) Representations and Warranties by the Company. The Company
represents and warrants to each Underwriter as of the date hereof and, solely
with respect to paragraph (vii) hereunder, to each Selling Stockholder as of the
date hereof, as of the Applicable Time referred to in Section 1(a)(i) hereof, as
of the Closing Time referred to in Section 2(c) hereof, and as of each Date of
Delivery (if any) referred to in Section 2(b) hereof, and agrees with each
Underwriter, as follows:

                  (i) Compliance with Registration Requirements. Each of the
         Registration Statement, any Rule 462(b) Registration Statement and any
         post-effective amendment thereto has become effective under the 1933
         Act and no stop order suspending the effectiveness of the Registration
         Statement, any Rule 462(b) Registration Statement or any post-effective
         amendment thereto is in effect under the 1933 Act and no proceedings
         for that purpose have been instituted or are pending or, to the
         knowledge of the Company, are contemplated by the Commission, and any
         request on the part of the Commission for additional information has
         been complied with.

                  At the respective times the Registration Statement, any Rule
         462(b) Registration Statement and any post-effective amendments thereto
         became effective and at the Closing Time (and, if any Option Securities
         are purchased, at the Date of Delivery), the Registration Statement,
         the Rule 462(b) Registration Statement and any amendments and
         supplements thereto complied and, as amended or supplemented, if
         applicable, will comply in all material respects with the requirements
         of the 1933 Act and the 1933 Act Regulations and did not and 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. Neither the Prospectus nor any
         amendments or supplements thereto, at the time the Prospectus or any
         such amendment or supplement was issued and at the Closing Time (and,
         if any Option Securities are purchased, at the Date of Delivery),
         included or will include an untrue statement of a material fact or
         omitted or


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         will omit to state a material fact necessary in order to make the
         statements therein, in the light of the circumstances under which they
         were made, not misleading.

                  As of the Applicable Time (as defined below), neither (x) the
         Issuer General Use Free Writing Prospectus(es) (as defined below)
         issued at or prior to the Applicable Time and the Statutory Prospectus
         (as defined below) as of the Applicable Time and the information
         included on Schedule C hereto, all considered together (collectively,
         the "General Disclosure Package"), nor (y) any individual Issuer
         Limited Use Free Writing Prospectus, when considered together with the
         General Disclosure Package, included any untrue statement of a material
         fact or omitted to state any material fact necessary in order to make
         the statements therein, in the light of the circumstances under which
         they were made, not misleading.

                  As used in this subsection and elsewhere in this Agreement:

                  "Applicable Time" means :00 [a/p]m (Eastern time) on [INSERT
         DATE] or such other time as agreed by the Company, Merrill Lynch and
         Lehman Brothers.

                  "Statutory Prospectus" as of any time means the prospectus
         relating to the Securities that is included in the Registration
         Statement immediately prior to that time, including any document
         incorporated by reference therein.

                  "Issuer Free Writing Prospectus" means any "issuer free
         writing prospectus," as defined in Rule 433 of the 1933 Act Regulations
         ("Rule 433"), relating to the Securities that (i) is required to be
         filed with the Commission by the Company, (ii) is a "road show that is
         a written communication" within the meaning of Rule 433(d)(8)(i)
         whether or not required to be filed with the Commission or (iii) is
         exempt from filing pursuant to Rule 433(d)(5)(i) because it contains a
         description of the Securities or of the offering that does not reflect
         the final terms, in each case in the form filed or required to be filed
         with the Commission or, if not required to be filed, in the form
         retained in the Company's records pursuant to Rule 433(g).

                  "Issuer General Use Free Writing Prospectus" means any Issuer
         Free Writing Prospectus that is intended for general distribution to
         prospective investors (other than a Bona Fide Electronic Road Show (as
         defined below)) and is specified in Schedule E hereto.

                  "Issuer Limited Use Free Writing Prospectus" means any Issuer
         Free Writing Prospectus that is not an Issuer General Use Free Writing
         Prospectus.

                  [The Company has made available a "bona fide electronic road
         show," as defined in Rule 433, in compliance with Rule 433(d)(8)(ii)
         (the "Bona Fide Electronic Road Show") such that no filing of any "road
         show" (as defined in Rule 433(h)) is required in connection with the
         offering of the Securities.]

                  Each Issuer Free Writing Prospectus, as of its issue date and
         at all subsequent times through the completion of the public offer and
         sale of the Securities or until any earlier date that the issuer
         notified or notifies Merrill Lynch and Lehman Brothers as described in
         Section 3(e), did not, does not and will not include any information
         that conflicted, conflicts or will conflict with the information
         contained in the Registration Statement or the Prospectus, and any
         preliminary or other prospectus deemed to be a part thereof that has
         not been superseded or modified.


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<PAGE>


                  The representations and warranties in this subsection shall
         not apply to statements in or omissions from the Registration
         Statement, the Prospectus or any Issuer Free Writing Prospectus made in
         reliance upon and in conformity with written information furnished to
         the Company by any Underwriter through the Representatives expressly
         for use therein.

                  Each preliminary prospectus (including the prospectus filed as
         part of the Registration Statement as originally filed or as part of
         any amendment thereto) complied when so filed in all material respects
         with the 1933 Act Regulations and each preliminary prospectus and the
         Prospectus delivered to the Underwriters for use in connection with
         this offering was identical in all material respects to the
         electronically transmitted copies thereof filed with the Commission
         pursuant to EDGAR, except to the extent permitted by Regulation S-T.

                  At the time of filing the Registration Statement, any 462(b)
         Registration Statement and any post-effective amendments thereto, at
         the earliest time thereafter that the Company or another offering
         participant made a bona fide offer (within the meaning of Rule
         164(h)(2) of the 1933 Act Regulations) of the Securities and at the
         date hereof, the Company was not and is not an "ineligible issuer," as
         defined in Rule 405 of the 1933 Act Regulations.

                  (ii) Independent Accountants. The accountants who certified
         the financial statements included in the Registration Statement are
         independent public accountants as required by the 1933 Act and the 1933
         Act Regulations.

                  (iii) Financial Statements. The consolidated financial
         statements included in the Registration Statement, the General
         Disclosure Package and the Prospectus, together with the related notes,
         present fairly the financial position of the Company and its
         consolidated subsidiaries at the dates indicated and the statements of
         operations, stockholders' equity and cash flows of the Company and its
         consolidated subsidiaries for the periods specified; said financial
         statements have been prepared in conformity with generally accepted
         accounting principles ("GAAP") applied on a consistent basis throughout
         the periods involved except where and to the extent noted therein. The
         supporting schedules, if any, present fairly in accordance with GAAP
         the information required to be stated therein. The selected financial
         data and the summary financial information included in the Prospectus
         present fairly the information shown therein and have been compiled on
         a basis consistent with that of the audited financial statements
         included in the Registration Statement. All disclosures contained in
         the Registration Statement, the General Disclosure Package or the
         Prospectus regarding "non-GAAP financial measures" (as such term is
         defined by the rules and regulations of the Commission), if any, comply
         with Regulation G under the Securities Exchange Act of 1934, as amended
         (the "1934 Act") and Item 10 of Regulation S-K under the 1933 Act, to
         the extent applicable.

                  (iv) No Material Adverse Change in Business. Since the
         respective dates as of which information is given in the Registration
         Statement, the General Disclosure Package or the Prospectus, except as
         otherwise stated therein, (A) there has been no material adverse
         change, nor has there been any development involving a prospective
         material adverse change, in the condition, financial or otherwise, or
         in the results of operations, stockholders' equity, properties,
         management, business affairs or business prospects of the Company and
         its subsidiaries considered as one enterprise, whether or not arising
         in the ordinary course of business (a "Material Adverse Effect"), (B)
         there has been no loss or interference with the Company's business from
         fire, explosion, flood or other calamity, whether or not covered by
         insurance, or from any labor dispute or court or governmental action,
         order or decree, nor has there been any change in the capital stock of
         the Company, (C) there have been no transactions entered into by the
         Company or any of its subsidiaries, other than those in the ordinary
         course of business, which


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         are material with respect to the Company and its subsidiaries
         considered as one enterprise, and (D) there has been no dividend or
         distribution of any kind declared, paid or made by the Company on any
         class of its capital stock.

                  (v) Good Standing of the Company. The Company has been duly
         organized and is validly existing as a corporation in good standing
         under the laws of the State of Delaware and has corporate power and
         authority to own, lease and operate its properties and to conduct its
         business as described in the Prospectus and to enter into and perform
         its obligations under this Agreement; and the Company is duly qualified
         as a foreign corporation to transact business and is in good standing
         in each other jurisdiction in which such qualification is required,
         whether by reason of the ownership or leasing of property or the
         conduct of business, except where the failure so to qualify or to be in
         good standing would not, individually or in the aggregate, result in a
         Material Adverse Effect.

                  (vi) Good Standing of Subsidiaries. Each "significant
         subsidiary" of the Company (as such term is defined in Rule 1-02 of
         Regulation S-X) and IPG Laser GmbH, IPG Fibertech S.R.L. and
         NTO-IRE-Polus (each a "Subsidiary" and, collectively, the
         "Subsidiaries") has been duly organized and is validly existing in good
         standing under the laws of the jurisdiction of its organization, has
         organizational power and authority to own, lease and operate its
         properties and to conduct its business as described in the Prospectus
         and is duly qualified to transact business and is in good standing in
         each jurisdiction in which such qualification is required, whether by
         reason of the ownership or leasing of property or the conduct of
         business, except where the failure so to qualify or to be in good
         standing would not, individually or in the aggregate, result in a
         Material Adverse Effect; except as otherwise disclosed in the
         Registration Statement, all of the issued and outstanding capital stock
         of each such Subsidiary has been duly authorized and validly issued, is
         fully paid and non-assessable and is owned by the Company, directly or
         through subsidiaries, free and clear of any security interest,
         mortgage, pledge, lien, encumbrance, claim or equity; none of the
         outstanding shares of capital stock of any Subsidiary was issued in
         violation of the preemptive or similar rights of any securityholder of
         such Subsidiary. The only subsidiaries of the Company are the
         subsidiaries listed on Exhibit 21 to the Registration Statement.

                  (vii) Capitalization. The authorized, issued and outstanding
         capital stock of the Company is as set forth in the Prospectus in the
         column entitled "Actual" under the caption "Capitalization" (except for
         subsequent issuances, if any, pursuant to this Agreement, pursuant to
         reservations, agreements or employee benefit plans referred to in the
         Prospectus or pursuant to the exercise of convertible securities or
         options referred to in the Prospectus). The shares of issued and
         outstanding capital stock, including the Securities to be purchased by
         the Underwriters from the Selling Stockholders, have been duly
         authorized and validly issued and are fully paid and non-assessable;
         none of the outstanding shares of capital stock, including the
         Securities to be purchased by the Underwriters from the Selling
         Stockholders, was issued in violation of the preemptive or other
         similar rights of any securityholder of the Company.

                  (viii) Authorization of Agreement. This Agreement has been
         duly authorized, executed and delivered by the Company.

                  (ix) Authorization and Description of Securities. The
         Securities to be purchased by the Underwriters from the Company have
         been duly authorized and, when issued and delivered by the Company
         pursuant to this Agreement against payment of the consideration set
         forth herein, will be validly issued and fully paid and non-assessable;
         the Common Stock conforms to all statements relating thereto contained
         in the Prospectus; the description of the Common Stock


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         contained in the Prospectus conforms to the instruments defining the
         rights of the holders of the Common Stock; no holder of the Securities
         will be subject to personal liability by reason of being such a holder;
         and the issuance of the Securities is not subject to the preemptive or
         other similar rights of any securityholder of the Company.

                  (x) Absence of Defaults and Conflicts. Neither the Company nor
         any of its subsidiaries is in violation of its charter or bylaws or in
         default in the performance or observance of any obligation, agreement,
         covenant or condition contained in any contract, indenture, mortgage,
         deed of trust, loan or credit agreement, note, lease or other agreement
         or instrument to which the Company or any of its subsidiaries is a
         party or by which it or any of them may be bound, or to which any of
         the property or assets of the Company or any subsidiary is subject
         (collectively, "Agreements and Instruments") except for such violations
         or defaults that would not result in a Material Adverse Effect; and the
         execution, delivery and performance of this Agreement and the
         consummation of the transactions contemplated herein and in the
         Registration Statement (including the issuance and sale of the
         Securities and the use of the proceeds from the sale of the Securities
         as described in the Prospectus under the caption "Use of Proceeds") and
         compliance by the Company with its obligations hereunder have been duly
         authorized by all necessary corporate action and do not and will not,
         whether with or without the giving of notice or passage of time or
         both, conflict with or constitute a breach of, or default or Repayment
         Event (as defined below) under, or result in the creation or imposition
         of any lien, charge or encumbrance upon any property or assets of the
         Company or any subsidiary pursuant to, the Agreements and Instruments
         (except for such conflicts, breaches, defaults or Repayment Events or
         liens, charges or encumbrances that would not result in a Material
         Adverse Effect), nor will such action result in any violation of the
         provisions of the charter or bylaws of the Company or any subsidiary or
         any applicable law, statute, rule, regulation, judgment, order, writ or
         decree of any government, government instrumentality or court, domestic
         or foreign, having jurisdiction over the Company or any subsidiary or
         any of their assets, properties or operations. As used herein, a
         "Repayment Event" means any event or condition which gives the holder
         of any note, debenture or other evidence of indebtedness (or any person
         acting on such holder's behalf) the right to require the repurchase,
         redemption or repayment of all or a portion of such indebtedness by the
         Company or any subsidiary.

                  (xi) Absence of Labor Dispute. No labor dispute with the
         employees of the Company or any subsidiary exists or, to the knowledge
         of the Company, is imminent, and the Company is not aware of any
         existing or imminent labor disturbance by the employees of any of its
         or any subsidiary's principal suppliers, manufacturers, customers or
         contractors, which, in either case, would result in a Material Adverse
         Effect.

                  (xii) Absence of Proceedings. There is no action, suit,
         proceeding, inquiry or investigation before or brought by any court or
         governmental agency or body, domestic or foreign, now pending, or, to
         the knowledge of the Company, threatened, against or affecting the
         Company or any subsidiary, which is required to be disclosed in the
         Registration Statement (other than as disclosed therein), or which
         might result in a Material Adverse Effect, or which might materially
         and adversely affect the consummation of the transactions contemplated
         in this Agreement or the performance by the Company of its obligations
         hereunder; the aggregate of all pending legal or governmental
         proceedings to which the Company or any subsidiary is a party or of
         which any of their respective property or assets is the subject which
         are not described in the Registration Statement, including ordinary
         routine litigation incidental to the business, could not result in a
         Material Adverse Effect.


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                  (xiii) Accuracy of Exhibits. There are no contracts or
         documents which are required to be described in the Registration
         Statement or the Prospectus or to be filed as exhibits thereto which
         have not been so described and filed as required.

                  (xiv) Possession of Intellectual Property. Except as would
         not, singly or in the aggregate, result in a Material Adverse Effect,
         the Company and its subsidiaries own or possess, or can acquire on
         reasonable terms, adequate patents, patent rights, licenses,
         inventions, copyrights, know-how (including trade secrets and other
         unpatented and/or unpatentable proprietary or confidential information,
         systems or procedures), trademarks, service marks, trade names or other
         intellectual property (collectively, "Intellectual Property") necessary
         to carry on or used in the business now operated by them, and neither
         the Company nor any of its subsidiaries has received any notice or is
         otherwise aware of any infringement of or conflict with asserted rights
         of others with respect to any Intellectual Property, or of any facts or
         circumstances which would render any Intellectual Property invalid or
         inadequate to protect the interest of the Company or any of its
         subsidiaries therein, and which infringement or conflict (if the
         subject of any unfavorable decision, ruling or finding) or invalidity
         or inadequacy, singly or in the aggregate, would result in a Material
         Adverse Effect.

                  (xv) Absence of Further Requirements. No filing with, or
         authorization, approval, consent, license, order, registration,
         qualification or decree of, any court or governmental authority or
         agency is necessary or required for the performance by the Company of
         its obligations hereunder, in connection with the offering, issuance or
         sale of the Securities by the Company hereunder or the consummation of
         the transactions contemplated by this Agreement, except such as have
         been already obtained or as may be required under the 1933 Act or the
         1933 Act Regulations or state securities laws or under the rules and
         regulations of the National Association of Securities Dealers, Inc.
         (the "NASD").

                  (xvi) Absence of Manipulation. Neither the Company nor any
         affiliate of the Company has taken, nor will the Company or any
         affiliate take, directly or indirectly, any action which is designed to
         or which has constituted or which would be expected to cause or result
         in stabilization or manipulation of the price of any security of the
         Company to facilitate the sale or resale of the Securities.

                  (xvii) Possession of Licenses and Permits. The Company and its
         subsidiaries possess such permits, licenses, approvals, consents and
         other authorizations (collectively, "Governmental Licenses") issued by
         the appropriate federal, state, local or foreign regulatory agencies or
         bodies necessary to conduct the business now operated by them, except
         where the failure so to possess would not, singly or in the aggregate,
         result in a Material Adverse Effect; the Company and its subsidiaries
         are in compliance with the terms and conditions of all such
         Governmental Licenses, except where the failure so to comply would not,
         singly or in the aggregate, result in a Material Adverse Effect; all of
         the Governmental Licenses are valid and in full force and effect,
         except when the invalidity of such Governmental Licenses or the failure
         of such Governmental Licenses to be in full force and effect would not,
         singly or in the aggregate, result in a Material Adverse Effect; and
         neither the Company nor any of its subsidiaries has received any notice
         of proceedings relating to the revocation or modification of any such
         Governmental Licenses which, singly or in the aggregate, if the subject
         of an unfavorable decision, ruling or finding, would result in a
         Material Adverse Effect.

                  (xviii) Title to Property. The Company and its subsidiaries
         have good and marketable title to all real property owned by the
         Company and its subsidiaries and good title to all other properties
         owned by them, in each case, free and clear of all mortgages, pledges,
         liens, security


                                      -7-
<PAGE>


         interests, claims, restrictions or encumbrances of any kind except such
         as (a) are described in the Prospectus or (b) do not, singly or in the
         aggregate, materially affect the value of such property and do not
         interfere with the use made and proposed to be made of such property by
         the Company or any of its subsidiaries; and all of the leases and
         subleases material to the business of the Company and its subsidiaries,
         considered as one enterprise, and under which the Company or any of its
         subsidiaries holds properties described in the Prospectus, are in full
         force and effect, and neither the Company nor any subsidiary has any
         notice of any material claim of any sort that has been asserted by
         anyone adverse to the rights of the Company or any subsidiary under any
         of the leases or subleases mentioned above, or affecting or questioning
         the rights of the Company or such subsidiary to the continued
         possession of the leased or subleased premises under any such lease or
         sublease.

                  (xix) Investment Company Act. The Company is not required, and
         upon the issuance and sale of the Securities as herein contemplated and
         the application of the net proceeds therefrom as described in the
         Prospectus will not be required, to register as an "investment company"
         under the Investment Company Act of 1940, as amended (the "1940 Act").

                  (xx) Environmental Laws. Except as described in the
         Registration Statement and except as would not, singly or in the
         aggregate, result in a Material Adverse Effect, (A) neither the Company
         nor any of its subsidiaries is in violation of any federal, state,
         local or foreign statute, law, rule, regulation, ordinance, code,
         policy or rule of common law or any judicial or administrative
         interpretation thereof, including any judicial or administrative order,
         consent, decree or judgment, relating to pollution or protection of
         human health, the environment (including, without limitation, ambient
         air, surface water, groundwater, land surface or subsurface strata) or
         wildlife, including, without limitation, laws and regulations relating
         to the release or threatened release of chemicals, pollutants,
         contaminants, wastes, toxic substances, hazardous substances, petroleum
         or petroleum products, asbestos-containing materials or mold
         (collectively, "Hazardous Materials") or to the manufacture,
         processing, distribution, use, treatment, storage, disposal, transport
         or handling of Hazardous Materials (collectively, "Environmental
         Laws"), (B) the Company and its subsidiaries have all permits,
         authorizations and approvals required under any applicable
         Environmental Laws and are each in compliance with their requirements,
         (C) there are no pending or threatened administrative, regulatory or
         judicial actions, suits, demands, demand letters, claims, liens,
         notices of noncompliance or violation, investigation or proceedings
         relating to any Environmental Law against the Company or any of its
         subsidiaries and (D) there are no events or circumstances that would
         reasonably be expected to form the basis of an order for clean-up or
         remediation, or an action, suit or proceeding by any private party or
         governmental body or agency, against or affecting the Company or any of
         its subsidiaries relating to Hazardous Materials or any Environmental
         Laws.

                  (xxi) Registration Rights. Except for such rights as have been
         waived with respect to the offering of Securities contemplated hereby
         or otherwise disclosed in the Registration Statement, General
         Disclosure Package and Prospectus, there are no persons with
         registration rights or other similar rights to have any securities
         registered pursuant to the Registration Statement or otherwise
         registered by the Company under the 1933 Act.

                  (xxii) Accounting Controls. The Company maintains a system of
         internal accounting controls sufficient to provide reasonable assurance
         that (A) transactions are executed in accordance with management's
         general or specific authorization; (B) transactions are recorded as
         necessary to permit preparation of financial statements in conformity
         with GAAP and to maintain accountability for assets; (C) access to
         assets is permitted only in accordance with management's general or
         specific authorization; and (D) the recorded accountability for assets
         is compared with


                                      -8-
<PAGE>


         the existing assets at reasonable intervals and appropriate action is
         taken with respect to any differences. Except as described in the
         Prospectus, since the end of the Company's most recent audited fiscal
         year, there has been (1) no material weakness in the Company's internal
         control over financial reporting (whether or not remediated) and (2) no
         change in the Company's internal control over financial reporting that
         has materially affected, or is reasonably likely to materially affect,
         the Company's internal control over financial reporting.

                  (xxiii) Compliance with the Sarbanes-Oxley Act. The Company
         has taken all necessary actions to ensure that, upon the effectiveness
         of the Registration Statement, it will be in compliance with all
         provisions of the Sarbanes-Oxley Act of 2002 and all rules and
         regulations promulgated thereunder or implementing the provisions
         thereof (the "Sarbanes-Oxley Act") that are then in effect and which
         the Company is required to comply with as of the effectiveness of the
         Registration Statement.

                  (xxiv) Payment of Taxes. All United States federal income tax
         returns of the Company and its subsidiaries required by law to be filed
         have been filed and all taxes shown by such returns or otherwise
         assessed, which are due and payable, have been paid, except assessments
         against which appeals have been or will be promptly taken and as to
         which adequate reserves have been provided. The United States federal
         income tax returns of the Company through the fiscal year ended
         December 31, 2001 have been audited by the Internal Revenue Service or
         closed by the applicable statute of limitations and no assessment in
         connection therewith has been made against the Company. The Company and
         its subsidiaries have filed all other tax returns that are required to
         have been filed by them pursuant to applicable foreign, state, local or
         other law except insofar as the failure to file such returns would not
         result in a Material Adverse Effect, and has paid all taxes due
         pursuant to such returns or pursuant to any assessment received by the
         Company and its subsidiaries, except for such taxes, if any, that are
         immaterial in amount or that are being contested in good faith and as
         to which adequate reserves have been provided. The charges, accruals
         and reserves on the books of the Company in respect of any income and
         corporation tax liability for any years not finally determined or
         closed by the applicable statute of limitations are adequate to meet
         any assessments or re-assessments for additional income tax for any
         years not finally determined or closed by the applicable statute of
         limitations, except to the extent of any inadequacy that would not
         result in a Material Adverse Effect.

                  (xxv) Insurance. The Company and its subsidiaries carry or are
         entitled to the benefits of insurance, in such amounts and covering
         such risks as is generally maintained by companies engaged in the same
         or similar business, and all such insurance is in full force and
         effect. The Company has no reason to believe that it will not be able
         (A) to renew its existing insurance coverage as and when such policies
         expire or (B) to obtain comparable coverage from similar institutions
         as may be necessary or appropriate to conduct its business as now
         conducted and at a cost that would not result in a Material Adverse
         Effect.

                  (xxvi) Statistical and Market-Related Data. Any statistical
         and market-related data included in the Registration Statement and the
         Prospectus are based on or derived from sources that the Company
         believes to be reliable and accurate, and the Company has obtained the
         written consent to the use of such data from such sources to the extent
         required.

                  (xxvii) Foreign Corrupt Practices Act. Neither the Company
         nor, to the knowledge of the Company, any director, officer, agent,
         employee, affiliate or other person acting on behalf of the Company or
         any of its subsidiaries is aware of or has taken any action, directly
         or indirectly, that would result in a violation by such persons of the
         Foreign Corrupt Practices Act of 1977, as amended, and the rules and
         regulations thereunder (the "FCPA"), including, without limitation,


                                      -9-
<PAGE>


         making use of the mails or any means or instrumentality of interstate
         commerce corruptly in furtherance of an offer, payment, promise to pay
         or authorization of the payment of any money, or other property, gift,
         promise to give, or authorization of the giving of anything of value to
         any "foreign official" (as such term is defined in the FCPA) or any
         foreign political party or official thereof or any candidate for
         foreign political office, in contravention of the FCPA and the Company
         and, to the knowledge of the Company, its affiliates have conducted
         their businesses in compliance with the FCPA and have instituted and
         maintain policies and procedures designed to ensure, and which are
         reasonably expected to continue to ensure, continued compliance
         therewith.

                  (xxviii) Money Laundering Laws. The operations of the Company
         are and have been conducted at all times in compliance with applicable
         financial recordkeeping and reporting requirements of the Currency and
         Foreign Transactions Reporting Act of 1970, as amended, the money
         laundering statutes of all jurisdictions, the rules and regulations
         thereunder and any related or similar rules, regulations or guidelines,
         issued, administered or enforced by any governmental agency
         (collectively, the "Money Laundering Laws") and no action, suit or
         proceeding by or before any court or governmental agency, authority or
         body or any arbitrator involving the Company with respect to the Money
         Laundering Laws is pending or, to the best knowledge of the Company,
         threatened.

                  (xxix) OFAC. Neither the Company nor, to the knowledge of the
         Company, any director, officer, agent, employee, affiliate or person
         acting on behalf of the Company is currently subject to any U.S.
         sanctions administered by the Office of Foreign Assets Control of the
         U.S. Treasury Department ("OFAC"); and the Company will not directly or
         indirectly use the proceeds of the offering, or lend, contribute or
         otherwise make available such proceeds to any subsidiary, joint venture
         partner or other person or entity, for the purpose of financing the
         activities of any person currently subject to any U.S. sanctions
         administered by OFAC.

                  (xxx) Securities Rating. None of the Company's securities have
         been or are rated by any "nationally recognized statistical rating
         organization" (as that term is defined for purposes of Rule 436(g)
         under the 1933 Act).

         (b) Representations and Warranties by the Selling Stockholders. Each
Selling Stockholder severally, and not jointly, represents and warrants to each
Underwriter as of the date hereof, as of the Closing Time, and, if the Selling
Stockholder is selling Option Securities on a Date of Delivery, as of each such
Date of Delivery, and agrees with each Underwriter, as follows:

                  (i) Accurate Disclosure. Such Selling Stockholder has reviewed
         and is familiar with the Registration Statement, the General Disclosure
         Package and the Prospectus and neither the General Disclosure Package,
         the Prospectus nor any amendment or supplement thereto includes any
         untrue statement of a material fact or omits to state a material fact
         necessary in order to make the statements therein, in the light of the
         circumstances under which they were made, not misleading; provided,
         however, that the foregoing representation and warranty, as it relates
         to such Selling Stockholder, is limited to any statement in the
         Registration Statement, the General Disclosure Package and the
         Prospectus, or any supplement or amendment thereto, concerning such
         Selling Stockholder furnished in writing by or on behalf of such
         Selling Stockholder to the Company expressly for use therein; such
         Selling Stockholder is not relying upon any material information
         concerning the Company or any subsidiary of the Company which is not
         set forth in the General Disclosure Package or the Prospectus in making
         its decision to sell the Securities to be sold by such Selling
         Stockholder hereunder.


                                      -10-
<PAGE>


                  (ii) Authorization of this Agreement. This Agreement has been
         duly authorized, executed and delivered by or on behalf of such Selling
         Stockholder.

                  (iii) Authorization of Power of Attorney and Custody
         Agreement. The Power of Attorney and Custody Agreement, each in the
         form heretofore furnished to the Representatives (the "Power of
         Attorney and Custody Agreement"), has been duly authorized, executed
         and delivered by such Selling Stockholder or its duly appointed
         attorney-in-fact and is the valid and binding agreement of such Selling
         Stockholder.

                  (iv) Noncontravention. The execution and delivery of this
         Agreement and the Power of Attorney and Custody Agreement, the sale and
         delivery of the Securities to be sold by such Selling Stockholder, the
         consummation of the transactions contemplated herein and compliance by
         such Selling Stockholder with its obligations hereunder do not and will
         not, whether with or without the giving of notice or passage of time or
         both, conflict with or constitute a breach of, or default under, or
         result in the creation or imposition of any tax, lien, charge or
         encumbrance upon the Securities to be sold by such Selling Stockholder
         or any property or assets of such Selling Stockholder pursuant to any
         contract, indenture, mortgage, deed of trust, loan or credit agreement,
         note, license, lease or other agreement or instrument to which such
         Selling Stockholder is a party or by which such Selling Stockholder may
         be bound, or to which any of the property or assets of such Selling
         Stockholder is subject, nor will such action result in any violation of
         the provisions of the charter or bylaws or other organizational
         instrument of such Selling Stockholder, if applicable, or any
         applicable treaty, law, statute, rule, regulation, judgment, order,
         writ or decree of any government, government instrumentality or court,
         domestic or foreign, having jurisdiction over such Selling Stockholder
         or any of its properties.

                  (v) Certificates Suitable for Transfer. The Securities to be
         sold by such Selling Stockholder pursuant to this Agreement are
         certificated securities in registered form and are not held in any
         securities account or by or through any securities intermediary within
         the meaning of the Uniform Commercial Code as in effect in the State of
         New York (the "UCC"). Certificates for all of the Securities to be sold
         by such Selling Stockholder pursuant to this Agreement, in suitable
         form for transfer by delivery or accompanied by duly executed
         instruments of transfer or assignment in blank with signatures
         guaranteed, have been placed in custody with o (the "Custodian"), with
         irrevocable conditional instructions to deliver such Securities to the
         Underwriters pursuant to this Agreement.

                  (vi) Valid Title. Such Selling Stockholder has, and at the
         Closing Time will have, valid title to the Securities to be sold by
         such Selling Stockholder free and clear of all security interests,
         claims, liens, equities or other encumbrances and the legal right and
         power, and all authorization and approval required by law, to enter
         into this Agreement and the Power of Attorney and Custody Agreement and
         to sell, transfer and deliver the Securities to be sold by such Selling
         Stockholder.

                  (vii) Delivery of Securities. Upon the Underwriters' acquiring
         possession of the Securities to be sold by such Selling Stockholder and
         paying the purchase price therefor pursuant to this Agreement, the
         Underwriters (assuming that no such Underwriter has notice of any
         "adverse claim," within the meaning of Section 8-105 of the New York
         Uniform Commercial Code, to such Securities) will acquire their
         respective interests in such Securities (including, without limitation,
         all rights that such Selling Stockholder had or has the power to
         transfer in such Securities) free and clear of any adverse claim within
         the meaning of Section 8-102 of the New York Uniform Commercial Code.


                                      -11-
<PAGE>


                  (viii) Absence of Manipulation. Such Selling Stockholder has
         not taken, and will not take, directly or indirectly, any action which
         is designed to or which has constituted or would be expected to cause
         or result in stabilization or manipulation of the price of any security
         of the Company to facilitate the sale or resale of the Securities.

                  (ix) Absence of Further Requirements. No filing with, or
         consent, approval, authorization, order, registration, qualification or
         decree of, any court or governmental authority or agency, domestic or
         foreign, is necessary or required for the performance by each Selling
         Stockholder of its obligations hereunder or in the Power of Attorney
         and Custody Agreement, or in connection with the sale and delivery of
         the Securities hereunder or the consummation of the transactions
         contemplated by this Agreement, except such as may have previously been
         made or obtained or as may be required under the 1933 Act or the 1933
         Act Regulations or state securities laws.

                  (x) Restriction on Sale of Securities. Such Selling
         Stockholder has previously delivered to the Representatives a lock-up
         agreement substantially in the form attached as Exhibit C hereto.

                  (xi) No Association with NASD. Except for those Selling
         Stockholders identified on Schedule 1(b)(xi), neither such Selling
         Stockholder nor any of his/her/its affiliates directly, or indirectly
         through one or more intermediaries, controls, or is controlled by, or
         is under common control with, or is a person associated with (within
         the meaning of Article I (dd) of the Bylaws of the National Association
         of Securities Dealers, Inc.), any member firm of the National
         Association of Securities Dealers, Inc.

         (c) Representations and Warranties by the Founder. In addition to the
representations and warranties contained in Section 1(b), Dr. Valentin P.
Gapontsev (the "Founder") further represents and warrants to each Underwriter
that he has reviewed and is familiar with the Registration Statement, the
General Disclosure Package and the Prospectus and: (i) has no knowledge of any
material fact, condition or information not disclosed in the Prospectus or any
supplement thereto which has adversely affected or may adversely affect the
business of the Company or any of its subsidiaries; and (ii) to his knowledge,
neither the General Disclosure Package, the Prospectus nor any amendments or
supplements thereto contains any untrue statement of a material fact or omits to
state a material fact necessary in order to make the statements therein, in the
light of the circumstances under which they were made, not misleading.

         (d) Officer's Certificates. Any certificate signed by any officer of
the Company or any of its subsidiaries delivered to the Representatives or to
counsel for the Underwriters in connection with the offering of the Securities
shall be deemed a representation and warranty by the Company to each Underwriter
as to the matters covered thereby; and any certificate signed by or on behalf of
the Selling Stockholders as such and delivered to the Representatives or to
counsel for the Underwriters in connection with the offering of the Securities
pursuant to the terms of this Agreement shall be deemed a representation and
warranty by such Selling Stockholder to the Underwriters as to the matters
covered thereby.

         SECTION 2. Sale and Delivery to Underwriters; Closing.

         (a) Initial Securities. On the basis of the representations and
warranties herein contained and subject to the terms and conditions herein set
forth, the Company and each Selling Stockholder, severally and not jointly,
agree to sell to each Underwriter, severally and not jointly, and each
Underwriter, severally and not jointly, agrees to purchase from the Company and
each Selling Stockholder, at the price


                                      -12-
<PAGE>


per share set forth in Schedule C, that proportion of the number of Initial
Securities set forth in Schedule B opposite the name of the Company or such
Selling Stockholder, as the case may be, which the number of Initial Securities
set forth in Schedule A opposite the name of such Underwriter, plus any
additional number of Initial Securities which such Underwriter may become
obligated to purchase pursuant to the provisions of Section 10 hereof, bears to
the total number of Initial Securities, subject, in each case, to such
adjustments among the Underwriters as the Representatives in their sole
discretion shall make to eliminate any sales or purchases of fractional
securities.

         (b) Option Securities. In addition, on the basis of the representations
and warranties herein contained and subject to the terms and conditions herein
set forth, the Selling Stockholders indicated on Schedule B hereto as selling
Option Securities hereunder, acting severally and not jointly, hereby grant an
option to the Underwriters to purchase, severally and not jointly, up to an
additional o shares of Common Stock, as set forth in Schedule B, at the price
per share set forth in Schedule C, less an amount per share equal to any
dividends or distributions declared by the Company and payable on the Initial
Securities but not payable on the Option Securities. The option hereby granted
will expire 30 days after the date hereof and may be exercised in whole or in
part from time to time only for the purpose of covering overallotments which may
be made in connection with the offering and distribution of the Initial
Securities upon notice by Merrill Lynch and Lehman Brothers to the
attorneys-in-fact (as set forth in the Power of Attorney and Custody Agreement)
and counsel (as set forth in Section 12 hereof) for the Selling Stockholders,
setting forth the number of Option Securities as to which the several
Underwriters are then exercising the option and the time and date of payment and
delivery for such Option Securities. Any such time and date of delivery (a "Date
of Delivery") shall be determined by the Representatives, but shall not be later
than seven full business days after the exercise of said option, nor in any
event prior to the Closing Time, as hereinafter defined. If the option is
exercised as to all or any portion of the Option Securities, each of the
Underwriters, acting severally and not jointly, will purchase that proportion of
the total number of Option Securities then being purchased which the number of
Initial Securities set forth in Schedule A opposite the name of such Underwriter
bears to the total number of Initial Securities, subject in each case to such
adjustments as the Representatives in their discretion shall make to eliminate
any sales or purchases of fractional shares.

         (c) Payment. Payment of the purchase price for, and delivery of
certificates for, the Initial Securities shall be made at the offices of Wilson
Sonsini Goodrich & Rosati, Professional Corporation, 1301 Avenue of the
Americas, 40th Floor, New York, New York 10019-6022, or at such other place as
shall be agreed upon by the Representatives, the Company and the Selling
Stockholders, at 9:00 A.M. (Eastern time) on the third (fourth, if the pricing
occurs after 4:30 P.M. (Eastern time) on any given day) business day after the
date hereof (unless postponed in accordance with the provisions of Section 10),
or such other time not later than ten business days after such date as shall be
agreed upon by the Representatives, the Company and the Selling Stockholders
(such time and date of payment and delivery being herein called "Closing Time").

         In addition, in the event that any or all of the Option Securities are
purchased by the Underwriters, payment of the purchase price for, and delivery
of certificates for, such Option Securities shall be made at the above-mentioned
offices, or at such other place as shall be agreed upon by the Representatives
and the Company and the Selling Stockholders, on each Date of Delivery as
specified in the notice from the Representatives to the Company and the Selling
Stockholders.

         Payment shall be made to the Company and the Selling Stockholders by
wire transfer of immediately available funds to bank accounts designated by the
Company and the Custodian pursuant to each Selling Stockholder's Power of
Attorney and Custody Agreement, as the case may be, against delivery to the
Representatives for the respective accounts of the Underwriters of certificates
for the Securities to be purchased by them. It is understood that each
Underwriter has authorized the


                                      -13-
<PAGE>


Representatives, for its account, to accept delivery of, receipt for, and make
payment of the purchase price for, the Initial Securities and the Option
Securities, if any, which it has agreed to purchase. Merrill Lynch and Lehman
Brothers, acting individually and not as representatives of the Underwriters,
may (but shall not be obligated to) make payment of the purchase price for the
Initial Securities or the Option Securities, if any, to be purchased by any
Underwriter whose funds have not been received by the Closing Time or the
relevant Date of Delivery, as the case may be, but such payment shall not
relieve such Underwriter from its obligations hereunder.

         (d) Denominations; Registration. Certificates for the Initial
Securities and the Option Securities, if any, shall be in such denominations and
registered in such names as the Representatives may request in writing at least
one full business day before the Closing Time or the relevant Date of Delivery,
as the case may be. The certificates for the Initial Securities and the Option
Securities, if any, will be made available for examination and packaging by the
Representatives in The City of New York not later than 10:00 A.M. (Eastern time)
on the business day prior to the Closing Time or the relevant Date of Delivery,
as the case may be.

         (e) Appointment of Qualified Independent Underwriter. The Company and
the Selling Stockholders hereby confirm their engagement of Lehman Brothers as,
and Lehman Brothers hereby confirms its agreement with the Company and the
Selling Stockholders to render services as, a "qualified independent
underwriter" within the meaning of Rule 2720 of the Conduct Rules of the
National Association of Securities Dealers, Inc. with respect to the offering
and sale of the Securities. Lehman Brothers, solely in its capacity as qualified
independent underwriter and not otherwise, is referred to herein as the
"Independent Underwriter."


         SECTION 3. Covenants of the Company and the Selling Stockholders. Each
of the Company and the Selling Stockholders, as applicable, covenants with each
Underwriter as follows:

         (a) Compliance with Securities Regulations and Commission Requests. The
Company, subject to Section 3(b), will comply with the requirements of Rule
430A, and will notify the Representatives immediately, and confirm the notice in
writing, (i) when any post-effective amendment to the Registration Statement
shall become effective, or any supplement to the Prospectus or any amended
Prospectus shall have been filed, (ii) of the receipt of any comments from the
Commission, (iii) of any request by the Commission for any amendment to the
Registration Statement or any amendment or supplement to the Prospectus or for
additional information, (iv) of the issuance by the Commission of any stop order
suspending the effectiveness of the Registration Statement or of any order
preventing or suspending the use of any preliminary prospectus, or of the
suspension of the qualification of the Securities for offering or sale in any
jurisdiction, or of the initiation or threatening of any proceedings for any of
such purposes or of any examination pursuant to Section 8(e) of the 1933 Act
concerning the Registration Statement and (v) if the Company becomes the subject
of a proceeding under Section 8A of the 1933 Act in connection with the offering
of the Securities. The Company will effect the filings required under Rule
424(b), in the manner and within the time period required by Rule 424(b)
(without reliance on Rule 424(b)(8)), and will take such steps as it deems
necessary to ascertain promptly whether the form of prospectus transmitted for
filing under Rule 424(b) was received for filing by the Commission and, in the
event that it was not, will promptly file such prospectus. The Company will use
its reasonable efforts to prevent the issuance of any stop order and, if any
stop order is issued, to obtain the lifting thereof at the earliest possible
moment.

         (b) Filing of Amendments and Exchange Act Documents. The Company will
give the Representatives notice of its intention to file or prepare any
amendment to the Registration Statement (including any filing under Rule 462(b))
or any amendment, supplement or revision to either the


                                      -14-
<PAGE>


prospectus included in the Registration Statement at the time it became
effective or to the Prospectus, and will furnish the Representatives with copies
of any such documents a reasonable amount of time prior to such proposed filing
or use, as the case may be, and will not file or use any such document to which
the Representatives or counsel for the Underwriters shall reasonably object in
writing. The Company has given the Representatives notice of any filings made
pursuant to the 1934 Act or 1934 Act Regulations within 48 hours prior to the
Applicable Time; the Company will give the Representatives notice of its
intention to make any such filing from the Applicable Time to the Closing Time
and will furnish the Representatives with copies of any such documents a
reasonable amount of time prior to such proposed filing, as the case may be, and
will not file or use any such document to which the Representatives or counsel
for the Underwriters shall reasonably object in writing.

         (c) Delivery of Registration Statements. The Company has furnished or
will deliver to the Representatives and counsel for the Underwriters, without
charge, signed copies of the Registration Statement as originally filed and of
each amendment thereto (including exhibits filed therewith) and signed copies of
all consents and certificates of experts, and will also deliver to the
Representatives, without charge, a conformed copy of the Registration Statement
as originally filed and of each amendment thereto (without exhibits) for each of
the Underwriters. The copies of the Registration Statement and each amendment
thereto furnished to the Underwriters will be identical to the electronically
transmitted copies thereof filed with the Commission pursuant to EDGAR, except
to the extent permitted by Regulation S-T.

         (d) Delivery of Prospectuses. The Company has delivered to each
Underwriter, without charge, as many copies of each preliminary prospectus as
such Underwriter reasonably requested, and the Company hereby consents to the
use of such copies for purposes permitted by the 1933 Act. The Company will
furnish to each Underwriter, without charge, during the period when the
Prospectus is required to be delivered under the 1933 Act, such number of copies
of the Prospectus (as amended or supplemented) as such Underwriter may
reasonably request. The Prospectus and any amendments or supplements thereto
furnished to the Underwriters will be identical to the electronically
transmitted copies thereof filed with the Commission pursuant to EDGAR, except
to the extent permitted by Regulation S-T.

         (e) Continued Compliance with Securities Laws. The Company will comply
with the 1933 Act and the 1933 Act Regulations so as to permit the completion of
the distribution of the Securities as contemplated in this Agreement and in the
Prospectus. If at any time when a prospectus is required by the 1933 Act to be
delivered in connection with sales of the Securities, any event shall occur or
condition shall exist as a result of which it is necessary, in the opinion of
counsel for the Underwriters or for the Company, to amend the Registration
Statement or amend or supplement the Prospectus in order that the Prospectus
will not include any untrue statements of a material fact or omit to state a
material fact necessary in order to make the statements therein not misleading
in the light of the circumstances existing at the time it is delivered to a
purchaser, or if it shall be necessary, in the opinion of such counsel, at any
such time to amend the Registration Statement or amend or supplement the
Prospectus in order to comply with the requirements of the 1933 Act or the 1933
Act Regulations, the Company will promptly prepare and file with the Commission,
subject to Section 3(b), such amendment or supplement as may be necessary to
correct such statement or omission or to make the Registration Statement or the
Prospectus comply with such requirements, and the Company will furnish to the
Underwriters such number of copies of such amendment or supplement as the
Underwriters may reasonably request. If at any time following issuance of an
Issuer Free Writing Prospectus there occurred or occurs an event or development
as a result of which such Issuer Free Writing Prospectus conflicted or would
conflict with the information contained in the Registration Statement relating
to the Securities or included or would include an untrue statement of a material
fact or omitted or would omit to state a material fact necessary in order to
make the statements therein, in the light of the circumstances, prevailing at
that subsequent time, not misleading, the Company will promptly notify Merrill
Lynch and Lehman Brothers and will promptly


                                      -15-
<PAGE>


amend or supplement, at its own expense, such Issuer Free Writing Prospectus to
eliminate or correct such conflict, untrue statement or omission.

         (f) Blue Sky Qualifications. The Company will use its best efforts, in
cooperation with the Underwriters, to qualify the Securities for offering and
sale under the applicable securities laws of such states and other jurisdictions
(domestic or foreign) as the Representatives may designate and to maintain such
qualifications in effect for a period of not less than one year from the later
of the effective date of the Registration Statement and any Rule 462(b)
Registration Statement; provided, however, that the Company shall not be
obligated to file any general consent to service of process or to qualify as a
foreign corporation or as a dealer in securities in any jurisdiction in which it
is not so qualified or to subject itself to taxation in respect of doing
business in any jurisdiction in which it is not otherwise so subject.

         (g) Rule 158. The Company will timely file such reports pursuant to the
1934 Act as are necessary in order to make generally available to its
securityholders as soon as practicable an earnings statement for the purposes
of, and to provide to the Underwriters the benefits contemplated by, the last
paragraph of Section 11(a) of the 1933 Act.

         (h) Use of Proceeds. The Company will use the net proceeds received by
it from the sale of the Securities in the manner specified in the Prospectus,
including under "Use of Proceeds."

         (i) Listing. The Company will use its best efforts to effect and
maintain the quotation of the Common Stock (including the Securities) on the
Nasdaq National Market.

         (j) Restriction on Sale of Securities. During a period of 180 days from
the date of the Prospectus, the Company will not, without the prior written
consent of the Representatives, (i) directly or indirectly, offer, pledge, sell,
contract to sell, sell any option or contract to purchase, purchase any option
or contract to sell, grant any option, right or warrant to purchase or otherwise
transfer or dispose of any share of Common Stock or any securities convertible
into or exercisable or exchangeable for Common Stock or file any registration
statement under the 1933 Act with respect to any of the foregoing, (ii) enter
into any swap or any other agreement or any transaction that transfers, in whole
or in part, directly or indirectly, the economic consequence of ownership of the
Common Stock, whether any such swap or transaction described in clause (i) or
(ii) above is to be settled by delivery of Common Stock or such other
securities, in cash or otherwise, or (iii) publicly announce the intention to do
any of the foregoing. The foregoing sentence shall not apply to (A) the
Securities to be sold hereunder, (B) any shares of Common Stock issued by the
Company upon the exercise of an option or warrant or the conversion of a
security outstanding on the date hereof and referred to in the Prospectus, (C)
any shares of Common Stock issued or options to purchase Common Stock granted
pursuant to existing employee benefit plans of the Company referred to in the
Prospectus or (D) any shares of Common Stock issued pursuant to any non-employee
director stock plan. Notwithstanding the foregoing, if (1) during the last 17
days of the 180-day restricted period the Company issues an earnings release or
material news or a material event relating to the Company occurs or (2) prior to
the expiration of the 180-day restricted period, the Company announces that it
will release earnings results or becomes aware that material news or a material
event will occur during the 16-day period beginning on the last day of the
180-day restricted period, the restrictions imposed in this clause (j) shall
continue to apply until the expiration of the 18-day period beginning on the
issuance of the earnings release or the occurrence of the material news or
material event.

         (k) Reporting Requirements. Subject to Section 3(b), the Company,
during the period when the Prospectus is required to be delivered under the 1933
Act, will file all documents required to be filed with the Commission pursuant
to the 1934 Act within the time periods required by the 1934 Act and the rules
and regulations of the Commission thereunder.


                                      -16-
<PAGE>


         (l) Issuer Free Writing Prospectuses. Each of the Company and each
Selling Stockholder represents and agrees that, unless it obtains the prior
consent of the Representatives, and each Underwriter represents and agrees that,
unless it obtains the prior consent of the Company and the Representatives, it
has not made and will not make any offer relating to the Securities that would
constitute an "issuer free writing prospectus," as defined in Rule 433, or that
would otherwise constitute a "free writing prospectus," as defined in Rule 405,
required to be filed with the Commission or, in the case of each Selling
Stockholder, whether or not required to be filed with the Commission. Any such
free writing prospectus consented to by the Company and the Representatives is
hereinafter referred to as a "Permitted Free Writing Prospectus." Each of the
Company and each Selling Stockholder represents that it has treated or agrees
that it will treat each Permitted Free Writing Prospectus as an "issuer free
writing prospectus," as defined in Rule 433, and has complied and will comply
with the requirements of Rule 433 applicable to any Permitted Free Writing
Prospectus, including timely filing with the Commission where required,
legending and record keeping.

         SECTION 4. Payment of Expenses.

         (a) Expenses. The Company will pay or cause to be paid all expenses
incident to the performance of its obligations under this Agreement, including
(i) the preparation, printing and filing of the Registration Statement
(including financial statements and exhibits) as originally filed and of each
amendment thereto, (ii) the preparation, printing and delivery to the
Underwriters of this Agreement, any Agreement among Underwriters and such other
documents as may be required in connection with the offering, purchase, sale,
issuance or delivery of the Securities, (iii) the preparation, issuance and
delivery of the certificates for the Securities to the Underwriters, including
any stock or other transfer taxes and any stamp or other duties payable upon the
sale, issuance or delivery of the Securities to the Underwriters, (iv) the fees
and disbursements of the Company's counsel, accountants and other advisors, (v)
the qualification of the Securities under securities laws in accordance with the
provisions of Section 3(f) hereof, including filing fees and the reasonable fees
and disbursements of counsel for the Underwriters in connection therewith and in
connection with the preparation of the Blue Sky survey and any supplement
thereto, (vi) the printing and delivery to the Underwriters of copies of each
preliminary prospectus, any Permitted Free Writing Prospectus and of the
Prospectus and any amendments or supplements thereto and any costs associated
with electronic delivery of any of the foregoing by the Underwriters to
investors, (vii) the preparation, printing and delivery to the Underwriters of
copies of the Blue Sky survey and any supplement thereto, (viii) the fees and
expenses of any transfer agent or registrar for the Securities, (ix) the costs
and expenses relating to any "road show" undertaken in connection with the
marketing of the Securities, including without limitation, (A) expenses
associated with the production of road show slides and graphics, (B) fees and
expenses of any consultants engaged in connection with the road show
presentations, (C) travel and lodging expenses of the representatives and
officers of the Company and any such consultants, and (D) one-half of the cost
of aircraft and other transportation chartered in connection with the road show
(not in excess of $175,000), (x) the filing fees incident to, and the reasonable
fees and disbursements of counsel to the Underwriters in connection with, the
review by the National Association of Securities Dealers, Inc. (the "NASD") of
the terms of the sale of the Securities, (xi) the fees and expenses incurred in
connection with the inclusion of the Securities in the Nasdaq National Market
and (xii) the fees and expenses of the Independent Underwriter in its capacity
as such.

         (b) Expenses of the Selling Stockholders. The Selling Stockholders will
pay all expenses incident to the performance of their respective obligations
under, and the consummation of the transactions contemplated by this Agreement,
including any stamp duties, capital duties and stock transfer taxes, if any,
payable upon the sale of the Securities to the Underwriters, and their transfer
between the Underwriters pursuant to an agreement between such Underwriters.


                                      -17-
<PAGE>


         (c) Termination of Agreement. If this Agreement is terminated by the
Representatives in accordance with the provisions of Section 5, Section 9(a)(i)
or Section 11 hereof, the Company shall reimburse the Underwriters for their
actual out-of-pocket documented expenses, including the reasonable fees and
disbursements of counsel for the Underwriters.

         (d) Allocation of Expenses. The provisions of this Section shall not
affect any agreement that the Company and the Selling Stockholders may make for
the sharing of such costs and expenses.

         SECTION 5. Conditions of Underwriters' Obligations. The obligations of
the several Underwriters hereunder are subject to the accuracy of the
representations and warranties of the Company, the Founder and the Selling
Stockholders contained in Section 1 hereof or in certificates of any officer of
the Company or any subsidiary of the Company or on behalf of any Selling
Stockholder delivered pursuant to the provisions hereof, to the performance by
the Company of its covenants and other obligations hereunder, and to the
following further conditions:

         (a) Effectiveness of Registration Statement. The Registration
Statement, including any Rule 462(b) Registration Statement, shall have become
effective and at Closing Time no stop order suspending the effectiveness of the
Registration Statement shall be in effect under the 1933 Act or proceedings
therefor initiated or threatened by the Commission, and any request on the part
of the Commission for additional information shall have been complied with to
the reasonable satisfaction of counsel to the Underwriters. A prospectus
containing the Rule 430A Information shall have been filed with the Commission
in the manner and within the time frame required by Rule 424(b) without reliance
on Rule 424(b)(8) or a post-effective amendment providing such information shall
have been filed and declared effective in accordance with the requirements of
Rule 430A.

         (b) Opinion of Counsel for Company. At Closing Time, the
Representatives shall have received the favorable opinions, each dated as of
Closing Time, of (A) Winston & Strawn LLP, counsel for the Company, to the
effect set forth in Exhibit A-1 hereto and (B) Fish & Richardson P.C., patent
counsel for the Company, to the effect set forth in Exhibit A-2 hereto, each in
form and substance satisfactory to counsel for the Underwriters, together with
signed or reproduced copies of such letter for each of the other Underwriters.

         (c) Opinion of Counsel for the Selling Stockholders. At Closing Time,
the Representatives shall have received the favorable opinion, dated as of
Closing Time, of Pryor Cashman Sherman & Flynn LLP, counsel for the Selling
Stockholders, in form and substance satisfactory to counsel for the
Underwriters, together with signed or reproduced copies of such letter for each
of the other Underwriters to the effect set forth in Exhibit B hereto and to
such further effect as counsel to the Underwriters may reasonably request.

         (d) Opinion of Counsel for Underwriters. At Closing Time, the
Representatives shall have received the favorable opinion, dated as of Closing
Time, of Wilson Sonsini Goodrich & Rosati, Professional Corporation, counsel for
the Underwriters, together with signed or reproduced copies of such letter for
each of the other Underwriters in form and substance satisfactory to the
Underwriters. In giving such opinion such counsel may rely, as to all matters
governed by the laws of jurisdictions other than the law of the State of New
York, the federal law of the United States and the General Corporation Law of
the State of Delaware, upon the opinions of counsel satisfactory to the
Representatives. Such counsel may also state that, insofar as such opinion
involves factual matters, they have relied, to the extent they deem proper, upon
certificates of officers of the Company and its subsidiaries and certificates of
public officials.


                                      -18-
<PAGE>


         (e) Officers' Certificate. At Closing Time, there shall not have been,
since the date hereof or since the respective dates as of which information is
given in the Prospectus or the General Disclosure Package, any material adverse
change in the condition, financial or otherwise, or in the results of
operations, stockholders' equity, properties, management, business affairs or
business prospects of the Company and its subsidiaries considered as one
enterprise, whether or not arising in the ordinary course of business, and the
Representatives shall have received a certificate of the President or a Vice
President of the Company and of the chief financial or chief accounting officer
of the Company, dated as of Closing Time, to the effect that (i) there has been
no such material adverse change, (ii) the representations and warranties in
Section 1(a) hereof are true and correct with the same force and effect as
though expressly made at and as of Closing Time, (iii) the Company has complied
with all agreements and satisfied all conditions on its part to be performed or
satisfied at or prior to Closing Time, and (iv) no stop order suspending the
effectiveness of the Registration Statement is in effect and no proceedings for
that purpose have been instituted or are pending or, to their knowledge,
contemplated by the Commission.

         (f) Certificate of Selling Stockholders. At Closing Time, the
Representatives shall have received a certificate of an Attorney-in-Fact on
behalf of each Selling Stockholder, dated as of Closing Time, to the effect that
(i) the representations and warranties of each Selling Stockholder contained in
Section 1(b) hereof are true and correct in all respects with the same force and
effect as though expressly made at and as of Closing Time and (ii) each Selling
Stockholder has complied in all material respects with all agreements and all
conditions on its part to be performed under this Agreement at or prior to
Closing Time.

         (g) Accountant's Comfort Letter. At the time of the execution of this
Agreement, the Representatives shall have received from Deloitte & Touche LLP a
letter dated such date, in form and substance satisfactory to the
Representatives, together with signed or reproduced copies of such letter for
each of the other Underwriters containing statements and information of the type
ordinarily included in accountants' "comfort letters" to underwriters with
respect to the financial statements and certain financial information contained
in the Registration Statement and the Statutory Prospectus.

         (h) Bring-down Comfort Letter. At Closing Time, the Representatives
shall have received from Deloitte & Touche LLP a letter, dated as of Closing
Time, stating as of the date of the bring-down letter (or, with respect to
matters involving changes or developments since the respective dates as of which
specified financial information is given in the Prospectus, as of a date not
more than three days prior to the date of the bring-down letter) that they
reaffirm the statements made in the letter furnished pursuant to subsection (g)
of this Section.

         (i) Approval of Listing. At Closing Time, the Securities shall have
been approved for inclusion in the Nasdaq National Market, subject only to
official notice of issuance.

         (j) No Objection. The NASD shall have confirmed that it has not raised
any objection with respect to the fairness and reasonableness of the
underwriting terms and arrangements.

         (k) Lock-up Agreements. At the date of this Agreement, the
Representatives shall have received an agreement substantially in the form of
Exhibit C hereto signed by the persons listed on Schedule D hereto.

         (l) No Material Adverse Change. Except as described in the Statutory
Prospectus, (i) neither the Company nor any of its subsidiaries shall have
sustained, since the date of the latest audited financial statements included in
the Statutory Prospectus, any loss or interference with its business from fire,
explosion, flood or other calamity, whether or not covered by insurance, or from
any labor dispute or court or governmental action, order or decree or (ii) since
such date there shall not have been any change


                                      -19-
<PAGE>


in the capital stock or long-term debt of the Company or any of its subsidiaries
or any change, or any development involving a prospective change, in or
affecting the condition (financial or otherwise), results of operations,
stockholders' equity, properties, management, business or prospects of the
Company and its subsidiaries considered as one enterprise, the effect of which,
in any such case described in clause (i) or (ii), is, in the judgment of the
Representatives, so material and adverse as to make it impracticable or
inadvisable to proceed with the public offering or the delivery of the
Securities being delivered on such Date of Delivery on the terms and in the
manner contemplated in the Prospectus.

         (m) Conditions to Purchase of Option Securities. In the event that the
Underwriters exercise their option provided in Section 2(b) hereof to purchase
all or any portion of the Option Securities, the representations and warranties
of the Company, the Founder and the Selling Stockholders contained herein and
the statements in any certificates furnished by the Company, any subsidiary of
the Company and the Selling Stockholders hereunder shall be true and correct as
of each Date of Delivery and, at the relevant Date of Delivery, the
Representatives shall have received:

                  (i) Officers' Certificate. A certificate, dated such Date of
         Delivery, of the President or a Vice President of the Company and of
         the chief financial or chief accounting officer of the Company
         confirming that the certificate delivered at the Closing Time pursuant
         to Section 5(e) hereof remains true and correct as of such Date of
         Delivery.

                  (ii) Certificate of Selling Stockholders. A certificate, dated
         such Date of Delivery, of an Attorney-in-Fact on behalf of each Selling
         Stockholder confirming that the certificate delivered at the Closing
         Time pursuant to Section 5(f) remains true and correct as of such Date
         of Delivery.

                  (iii) Opinion of Counsel for Company. The favorable opinions
         of (A) Winston & Strawn LLP, counsel for the Company, and (B) Fish &
         Richardson P.C., patent counsel for the Company, each in form and
         substance satisfactory to counsel for the Underwriters, dated such Date
         of Delivery, relating to the Option Securities to be purchased on such
         Date of Delivery and otherwise to the same effect as the opinions
         required by Section 5(b) hereof.

                  (iv) Opinion of Counsel for the Selling Stockholders. The
         favorable opinion of Pryor Cashman Sherman & Flynn LLP, counsel for the
         Selling Stockholders, in form and substance satisfactory to counsel for
         the Underwriters, dated such Date of Delivery, relating to the Option
         Securities to be purchased on such Date of Delivery and otherwise to
         the same effect as the opinion required by Section 5(c) hereof.

                  (v) Opinion of Counsel for Underwriters. The favorable opinion
         of Wilson Sonsini Goodrich & Rosati, Professional Corporation, counsel
         for the Underwriters, dated such Date of Delivery, relating to the
         Option Securities to be purchased on such Date of Delivery and
         otherwise to the same effect as the opinion required by Section 5(d)
         hereof.

                  (vi) Bring-down Comfort Letter. A letter from Deloitte &
         Touche LLP, in form and substance satisfactory to the Representatives
         and dated such Date of Delivery, substantially in the same form and
         substance as the letter furnished to the Representatives pursuant to
         Section 5(g) hereof, except that the "specified date" in the letter
         furnished pursuant to this paragraph shall be a date not more than five
         days prior to such Date of Delivery.

         (n) Additional Documents. At Closing Time and at each Date of Delivery,
counsel for the Underwriters shall have been furnished with such documents and
opinions as they may reasonably require for the purpose of enabling them to pass
upon the issuance and sale of the Securities as herein


                                      -20-
<PAGE>


contemplated, or in order to evidence the accuracy of any of the representations
or warranties, or the fulfillment of any of the conditions, herein contained;
and all proceedings taken by the Company and the Selling Stockholders in
connection with the issuance and sale of the Securities as herein contemplated
shall be reasonably satisfactory in form and substance to the Representatives
and counsel for the Underwriters.

         (o) Termination of Agreement. If any condition specified in this
Section shall not have been fulfilled when and as required to be fulfilled, this
Agreement, or, in the case of any condition to the purchase of Option Securities
on a Date of Delivery which is after the Closing Time, the obligations of the
several Underwriters to purchase the relevant Option Securities, may be
terminated by the Representatives by notice to the Company and the Selling
Stockholders at any time at or prior to Closing Time or such Date of Delivery,
as the case may be, and such termination shall be without liability of any party
to any other party except as provided in Section 4 and except that Sections 1,
6, 7 and 8 shall survive any such termination and remain in full force and
effect.

         SECTION 6. Indemnification.

         (a) Indemnification of Underwriters by the Company. (1) The Company
agrees to indemnify and hold harmless each Underwriter, its affiliates, as such
term is defined in Rule 501(b) under the 1933 Act (each, an "Affiliate"), its
selling agents and each person, if any, who controls any Underwriter within the
meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act as follows:

                  (i) against any and all loss, liability, claim, damage and
         expense whatsoever, as incurred, arising out of any untrue statement or
         alleged untrue statement of a material fact contained in the
         Registration Statement (or any amendment thereto), including the Rule
         430A Information or the omission or alleged omission therefrom of a
         material fact required to be stated therein or necessary to make the
         statements therein not misleading or arising out of any untrue
         statement or alleged untrue statement of a material fact included in
         any preliminary prospectus, any Issuer Free Writing Prospectus, the
         Prospectus (or any amendment or supplement thereto), any "road show"
         (as defined in Rule 433) not constituting an Issuer Free Writing
         Prospectus (a "Non-Prospectus Road Show") or any Blue Sky application
         or other document prepared or executed by the Company (or based upon
         any written information furnished by the Company for use therein)
         specifically for the purpose of qualifying any or all of the Securities
         under the securities laws of any state or other jurisdiction (any such
         application, document or information being hereinafter called a "Blue
         Sky Application"), or the omission or alleged omission therefrom of a
         material fact necessary in order to make the statements therein, in the
         light of the circumstances under which they were made, not misleading;

                  (ii) against any and all loss, liability, claim, damage and
         expense whatsoever, as incurred, to the extent of the aggregate amount
         paid in settlement of any litigation, or any investigation or
         proceeding by any governmental agency or body, commenced or threatened,
         or of any claim whatsoever based upon any such untrue statement or
         omission, or any such alleged untrue statement or omission; provided
         that (subject to Section 6(e) below) any such settlement is effected
         with the written consent of the Company;

                  (iii) against any and all expense whatsoever, as incurred
         (including the fees and disbursements of counsel chosen by Merrill
         Lynch and Lehman Brothers), reasonably incurred in investigating,
         preparing or defending against any litigation, or any investigation or
         proceeding by any governmental agency or body, commenced or threatened,
         or any claim whatsoever based upon any such untrue statement or
         omission, or any such alleged untrue statement or omission, to the
         extent that any such expense is not paid under (i) or (ii) above;


                                      -21-
<PAGE>


provided, however, that this indemnity agreement shall not apply to any loss,
liability, claim, damage or expense to the extent arising out of any untrue
statement or omission or alleged untrue statement or omission made in reliance
upon and in conformity with written information furnished to the Company by any
Underwriter through Merrill Lynch and Lehman Brothers expressly for use in the
Registration Statement (or any amendment thereto), including the Rule 430A
Information, or any preliminary prospectus, any Issuer Free Writing Prospectus
or the Prospectus (or any amendment or supplement thereto).

(2) In addition to and without limitation of the Company's obligation to
indemnify Lehman Brothers as an Underwriter, the Company also agrees to
indemnify and hold harmless the Independent Underwriter, its Affiliates and
selling agents and each person, if any, who controls the Independent Underwriter
within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act,
from and against any and all loss, liability, claim, damage and expense
whatsoever, as incurred, incurred as a result of the Independent Underwriter's
participation as a "qualified independent underwriter" within the meaning of
Rule 2720 of the Conduct Rules of the National Association of Securities
Dealers, Inc. in connection with the offering of the Securities.

         (b) Indemnification of Underwriters by the Founder. The Founder agrees
to indemnify and hold harmless each Underwriter, its Affiliates, its selling
agents and each person, if any, who controls any Underwriter within the meaning
of Section 15 of the 1933 Act or Section 20 of the 1934 Act to the extent and in
the manner set forth in clauses (a)(i), (ii) and (iii) above; provided, however,
that the aggregate indemnification liability of the Founder shall not exceed the
net proceeds received by the Founder from the sale of the Securities sold by the
Founder in the public offering pursuant to this Agreement; provided, further,
that the Founder shall only be required to indemnify and hold harmless each
Underwriter, its Affiliates, its selling agents and each person, if any, who
controls any Underwriter within the meaning of Section 15 of the 1933 Act or
Section 20 of the 1934 Act to the extent that he had knowledge of such untrue
statement or alleged untrue statement of a material fact contained in the
Registration Statement, any preliminary prospectus, the Prospectus, any
Non-Prospectus Road Show, any Blue Sky Application or such amendment or
supplement or the omission or alleged omission therefrom of a material fact
necessary in order to make the statements therein, in the light of the
circumstances under which they were made, not misleading.

         (c) Indemnification of Underwriters by the Selling Stockholders. Each
Selling Stockholder, severally and not jointly, agrees to indemnify and hold
harmless each Underwriter, its Affiliates, its selling agents and each person,
if any, who controls any Underwriter within the meaning of Section 15 of the
1933 Act or Section 20 of the 1934 Act to the extent and in the manner set forth
in clauses (a)(i), (ii) and (iii) above; provided, however, that the aggregate
indemnification liability of each Selling Stockholder shall not exceed the net
proceeds received by such person for the sale of the Securities sold by such
person in the public offering pursuant to this Agreement; and provided, further,
that each Selling Stockholder shall be liable only to the extent that such
untrue statement or omission or alleged untrue statement or omission has been
made in the Registration Statement, any preliminary prospectus, the Prospectus,
any Non-Prospectus Road Show, any Blue Sky Application or such amendment or
supplement in reliance upon and in conformity with information furnished by such
Selling Stockholder expressly for use in such document.

         (d) Indemnification of Company, Directors and Officers and Selling
Stockholders. Each Underwriter severally agrees to indemnify and hold harmless
the Company, its directors, each of its officers who signed the Registration
Statement, and each person, if any, who controls the Company within the meaning
of Section 15 of the 1933 Act or Section 20 of the 1934 Act, and each Selling
Stockholder against any and all loss, liability, claim, damage and expense
described in the indemnity contained in subsection (a)(1) of this Section, as
incurred, but only with respect to untrue statements or


                                      -22-
<PAGE>


omissions, or alleged untrue statements or omissions, made in the Registration
Statement (or any amendment thereto), including the Rule 430A Information or any
preliminary prospectus, any Issuer Free Writing Prospectus, any Non-Prospectus
Road Show, any Blue Sky Application or the Prospectus (or any amendment or
supplement thereto) in reliance upon and in conformity with written information
furnished to the Company by such Underwriter through Merrill Lynch and Lehman
Brothers expressly for use therein.

         (e) Actions against Parties; Notification. Each indemnified party shall
give notice as promptly as reasonably practicable to each indemnifying party of
any action commenced against it in respect of which indemnity may be sought
hereunder, but failure to so notify an indemnifying party shall not relieve such
indemnifying party from any liability hereunder to the extent it is not
materially prejudiced as a result thereof and in any event shall not relieve it
from any liability which it may have otherwise than on account of this indemnity
agreement. In the case of parties indemnified pursuant to Section 6(a)(1), (b)
and (c) above, counsel to the indemnified parties shall be selected by Merrill
Lynch and Lehman Brothers, and, in the case of parties indemnified pursuant to
Section 6(d) above, counsel to the indemnified parties shall be selected by the
Company. An indemnifying party may participate at its own expense in the defense
of any such action; provided, however, that counsel to the indemnifying party
shall not (except with the consent of the indemnified party) also be counsel to
the indemnified party. In no event shall the indemnifying parties be liable for
fees and expenses of more than one counsel (in addition to any local counsel)
separate from their own counsel for all indemnified parties in connection with
any one action or separate but similar or related actions in the same
jurisdiction arising out of the same general allegations or circumstances;
provided, that, if indemnity is sought pursuant to Section 6(a)(2), then, in
addition to the fees and expenses of such counsel for the indemnified parties,
the indemnifying party shall be liable for the reasonable fees and expenses of
not more than one counsel (in addition to any local counsel) separate from its
own counsel and that of the other indemnified parties for the Independent
Underwriter in its capacity as a "qualified independent underwriter" and all
persons, if any, who control the Independent Underwriter within the meaning of
Section 15 of the 1933 Act or Section 20 of 1934 Act in connection with any one
action or separate but similar or related actions in the same jurisdiction
arising out of the same general allegations or circumstances if, in the
reasonable judgment of the Independent Underwriter, there may exist a conflict
of interest between the Independent Underwriter and the other indemnified
parties. Any such separate counsel for the Independent Underwriter and such
control persons of the Independent Underwriter shall be designated in writing by
the Independent Underwriter. No indemnifying party shall, without the prior
written consent of the indemnified parties, settle or compromise or consent to
the entry of any judgment with respect to any litigation, or any investigation
or proceeding by any governmental agency or body, commenced or threatened, or
any claim whatsoever in respect of which indemnification or contribution could
be sought under this Section 6 or Section 7 hereof (whether or not the
indemnified parties are actual or potential parties thereto), unless such
settlement, compromise or consent (i) includes an unconditional release of each
indemnified party from all liability arising out of such litigation,
investigation, proceeding or claim and (ii) 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.

         (f) Settlement without Consent if Failure to Reimburse. If at any time
an indemnified party shall have requested an indemnifying party to reimburse the
indemnified party for fees and expenses of counsel, such indemnifying party
agrees that it shall be liable for any settlement of the nature contemplated by
Section 6(a)(1)(ii) effected without its written consent if (i) such settlement
is entered into more than 45 days after receipt by such indemnifying party of
the aforesaid request, (ii) such indemnifying party shall have received notice
of the terms of such settlement at least 30 days prior to such settlement being
entered into and (iii) such indemnifying party shall not have reimbursed such
indemnified party in accordance with such request prior to the date of such
settlement.


                                      -23-
<PAGE>


         (g) Other Agreements with Respect to Indemnification. The provisions of
this Section 6 shall not affect any agreement among the Company and the Selling
Stockholders with respect to indemnification.

         SECTION 7. Contribution. If the indemnification provided for in Section
6 hereof is for any reason unavailable to or insufficient to hold harmless an
indemnified party in respect of any losses, liabilities, claims, damages or
expenses referred to therein, then each indemnifying party shall contribute to
the aggregate amount of such losses, liabilities, claims, damages and expenses
incurred by such indemnified party, as incurred, (i) in such proportion as is
appropriate to reflect the relative benefits received by the Company and the
Selling Stockholders on the one hand and the Underwriters on the other hand from
the offering of the Securities pursuant to this Agreement or (ii) if the
allocation provided by clause (i) 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 Company and the
Selling Stockholders on the one hand and of the Underwriters on the other hand
in connection with the statements or omissions which resulted in such losses,
liabilities, claims, damages or expenses, as well as any other relevant
equitable considerations.

         The relative benefits received by the Company and the Selling
Stockholders on the one hand and the Underwriters on the other hand in
connection with the offering of the Securities pursuant to this Agreement shall
be deemed to be in the same respective proportions as the total net proceeds
from the offering of the Securities pursuant to this Agreement (before deducting
expenses) received by the Company and the Selling Stockholders and the total
underwriting discount received by the Underwriters, in each case as set forth on
the cover of the Prospectus, bear to the aggregate initial public offering price
of the Securities as set forth on the cover of the Prospectus.

         The relative fault of the Company and the Selling Stockholders on the
one hand and the Underwriters on the other hand shall be determined by reference
to, among other things, whether any such untrue or alleged untrue statement of a
material fact or omission or alleged omission to state a material fact relates
to information supplied by the Company or the Selling Stockholders or by the
Underwriters and the parties' relative intent, knowledge, access to information
and opportunity to correct or prevent such statement or omission.

         The Company, the Selling Stockholders and the Underwriters agree that
Lehman Brothers will not receive any additional benefits hereunder for serving
as the Independent Underwriter in connection with the offering and sale of the
Securities.

         The Company, the Selling Stockholders and the Underwriters agree that
it would not be just and equitable if contribution pursuant to this Section 7
were determined by pro rata allocation (even if the Underwriters were treated as
one entity for such purpose) or by any other method of allocation which does not
take account of the equitable considerations referred to above in this Section
7. The aggregate amount of losses, liabilities, claims, damages and expenses
incurred by an indemnified party and referred to above in this Section 7 shall
be deemed to include any legal or other expenses reasonably incurred by such
indemnified party in investigating, preparing or defending against any
litigation, or any investigation or proceeding by any governmental agency or
body, commenced or threatened, or any claim whatsoever based upon any such
untrue or alleged untrue statement or omission or alleged omission.

         Notwithstanding the provisions of this Section 7, no Underwriter shall
be required to contribute any amount in excess of the amount by which the total
price at which the Securities underwritten by it and distributed to the public
were offered to the public exceeds the amount of any damages which such
Underwriter has otherwise been required to pay by reason of any such untrue or
alleged untrue statement or omission or alleged omission.


                                      -24-
<PAGE>


         Notwithstanding the provisions of this Section 7, no Selling
Stockholder shall be required to contribute in the aggregate any amount in
excess of the amount of the net proceeds received by such Selling Stockholder
for the sale of the Securities sold by such person in the public offering
pursuant to this Agreement.

         No person guilty of fraudulent misrepresentation (within the meaning of
Section 11(f) of the 1933 Act) shall be entitled to contribution from any person
who was not guilty of such fraudulent misrepresentation.

         For purposes of this Section 7, each person, if any, who controls an
Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of
the 1934 Act and each Underwriter's Affiliates and selling agents shall have the
same rights to contribution as such Underwriter, and each director of the
Company, each officer of the Company who signed the Registration Statement, and
each person, if any, who controls the Company or any Selling Stockholder within
the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act shall
have the same rights to contribution as the Company or such Selling Stockholder,
as the case may be. The Underwriters' and the Selling Stockholders' respective
obligations to contribute pursuant to this Section 7 are several in proportion
to the number of Initial Securities set forth opposite their respective names in
Schedule A hereto or the amount of Securities sold, respectively, and not joint.

         SECTION 8. Representations, Warranties and Agreements to Survive. All
representations, warranties and agreements contained in this Agreement or in
certificates of officers of the Company or any of its subsidiaries or the
Selling Stockholders submitted pursuant hereto, shall remain operative and in
full force and effect regardless of (i) any investigation made by or on behalf
of any Underwriter or its Affiliates or selling agents, any person controlling
any Underwriter, its officers or directors, any person controlling the Company
or any person controlling any Selling Stockholder and (ii) delivery of and
payment for the Securities.

         SECTION 9. Termination of Agreement.

         (a) Termination; General. The Representatives may terminate this
Agreement, by notice to the Company and the Selling Stockholders, at any time at
or prior to Closing Time (i) if there has been, since the time of execution of
this Agreement or since the respective dates as of which information is given in
the Prospectus or General Disclosure Package, any material adverse change in the
condition, financial or otherwise, or in the results of operations,
stockholders' equity, properties, management, business affairs or business
prospects of the Company and its subsidiaries considered as one enterprise,
whether or not arising in the ordinary course of business, or (ii) if there has
occurred any material adverse change in the financial markets in the United
States or the international financial markets, any outbreak of hostilities or
escalation thereof or other calamity or crisis or any change or development
involving a prospective change in national or international political, financial
or economic conditions, including, without limitation, as a result of terrorist
activities after the date hereof, in each case the effect of which is such as to
make it, in the judgment of the Representatives, impracticable or inadvisable to
market the Securities or to enforce contracts for the sale of the Securities, or
(iii) if trading in any securities of the Company has been suspended or
materially limited by the Commission or the Nasdaq National Market, or if
trading generally on the American Stock Exchange or the New York Stock Exchange
or in the Nasdaq National Market has been suspended or materially limited, or
minimum or maximum prices for trading have been fixed, or maximum ranges for
prices have been required, by any of said exchanges or by such system or by
order of the Commission, the National Association of Securities Dealers, Inc. or
any other governmental authority, or (iv) a material disruption has occurred in
commercial banking or securities settlement or clearance services in the United
States, or (v) if a banking moratorium has been declared by either Federal or
New York authorities.


                                      -25-
<PAGE>


         (b) Liabilities. If this Agreement is terminated pursuant to this
Section, such termination shall be without liability of any party to any other
party except as provided in Section 4 hereof, and provided further that Sections
1, 6, 7 and 8 shall survive such termination and remain in full force and
effect.

         SECTION 10. Default by One or More of the Underwriters. If one or more
of the Underwriters shall fail at the Closing Time or a Date of Delivery to
purchase the Securities which it or they are obligated to purchase under this
Agreement (the "Defaulted Securities"), the Representatives shall have the
right, within 24 hours thereafter, to make arrangements for one or more of the
non-defaulting Underwriters, or any other underwriters, to purchase all, but not
less than all, of the Defaulted Securities in such amounts as may be agreed upon
and upon the terms herein set forth; if, however, the Representatives shall not
have completed such arrangements within such 24-hour period, then:

                  (i) if the number of Defaulted Securities does not exceed 10%
         of the number of Securities to be purchased on such date, each of the
         non-defaulting Underwriters shall be obligated, severally and not
         jointly, to purchase the full amount thereof in the proportions that
         their respective underwriting obligations hereunder bear to the
         underwriting obligations of all non-defaulting Underwriters, or

                  (ii) if the number of Defaulted Securities exceeds 10% of the
         number of Securities to be purchased on such date, this Agreement or,
         with respect to any Date of Delivery which occurs after the Closing
         Time, the obligation of the Underwriters to purchase and of the Selling
         Stockholders to sell the Option Securities to be purchased and sold on
         such Date of Delivery shall terminate without liability on the part of
         any non-defaulting Underwriter.

         No action taken pursuant to this Section 10 shall relieve any
defaulting Underwriter from liability in respect of its default.

         In the event of any such default which does not result in a termination
of this Agreement or, in the case of a Date of Delivery which is after the
Closing Time, which does not result in a termination of the obligation of the
Underwriters to purchase and the Selling Stockholder to sell the relevant Option
Securities, as the case may be, either the (i) Representatives or (ii) the
Company and any Selling Stockholder shall have the right to postpone the Closing
Time or the relevant Date of Delivery, as the case may be, for a period not
exceeding seven days in order to effect any required changes in the Registration
Statement or Prospectus or in any other documents or arrangements. As used
herein, the term "Underwriter" includes any person substituted for an
Underwriter under this Section 10.

         SECTION 11. Default by One or More of the Selling Stockholders or the
Company.

         (a) If a Selling Stockholder shall fail at the Closing Time or at a
Date of Delivery to sell and deliver the number of Securities which such Selling
Stockholder or Selling Stockholders are obligated to sell hereunder, and the
remaining Selling Stockholders do not exercise the right hereby granted to
increase, pro rata or otherwise, the number of Securities to be sold by them
hereunder to the total number to be sold by all Selling Stockholders as set
forth in Schedule B hereto, then the Underwriters may, at option of the
Representatives, by notice from the Representatives to the Company and the
non-defaulting Selling Stockholders, either (i) terminate this Agreement without
any liability on the fault of any non-defaulting party except that the
provisions of Sections 1, 4, 6, 7 and 8 shall remain in full force and effect or
(ii) elect to purchase the Securities which the non-defaulting Selling
Stockholders and the Company have agreed to sell hereunder. No action taken
pursuant to this Section 11 shall relieve any Selling Stockholder so defaulting
from liability, if any, in respect of such default.


                                      -26-
<PAGE>


         In the event of a default by any Selling Stockholder as referred to in
this Section 11, each of the Representatives, the Company and the non-defaulting
Selling Stockholders shall have the right to postpone the Closing Time or the
Date of Delivery for a period not exceeding seven days in order to effect any
required change in the Registration Statement or Prospectus or in any other
documents or arrangements.

         (b) If the Company shall fail at the Closing Time or at the Date of
Delivery to sell the number of Securities that it is obligated to sell
hereunder, then this Agreement shall terminate without any liability on the part
of any nondefaulting party; provided, however, that the provisions of Sections
1, 4, 6, 7 and 8 shall remain in full force and effect. No action taken pursuant
to this Section shall relieve the Company from liability, if any, in respect of
such default.

         SECTION 12. Notices. All notices and other communications hereunder
shall be in writing and shall be deemed to have been duly given if mailed or
transmitted by any standard form of telecommunication. Notices to the
Underwriters shall be directed to Merrill Lynch at 4 World Financial Center, New
York, New York 10080, attention of o and to Lehman Brothers Inc., 745 Seventh
Avenue, New York, New York 10019, Attention: Syndicate Registration (Fax:
646-834-8133), with a copy, in the case of any notice pursuant to Section 6(e),
to the Director of Litigation, Office of the General Counsel, Lehman Brothers
Inc., 399 Park Avenue, 10th Floor, New York, New York 10022 (Fax: 212-520-0421);
notices to the Company shall be directed to it at 50 Old Webster Road, Oxford,
Massachusetts 01540, attention General Counsel; and notices to the Selling
Stockholders shall be directed to Pryor Cashman Sherman & Flynn LLP, 410 Park
Avenue, New York, New York 10022 (Fax: 212-798-6312), attention of Richard
Frazer.

         SECTION 13. No Advisory or Fiduciary Relationship. Each of the Company
and each Selling Stockholder acknowledges and agrees that (a) the purchase and
sale of the Securities pursuant to this Agreement, including the determination
of the public offering price of the Securities and any related discounts and
commissions, is an arm's-length commercial transaction between the Company and
the Selling Stockholder, on the one hand, and the several Underwriters, on the
other hand, (b) in connection with the offering contemplated hereby and the
process leading to such transaction each Underwriter is and has been acting
solely as a principal and is not the agent or fiduciary of the Company or any
Selling Stockholder, or its respective stockholders, creditors, employees or any
other party, (c) no Underwriter has assumed or will assume an advisory or
fiduciary responsibility in favor of the Company or any Selling Stockholder with
respect to the offering contemplated hereby or the process leading thereto
(irrespective of whether such Underwriter has advised or is currently advising
the Company or any Selling Stockholder on other matters) and no Underwriter has
any obligation to the Company or any Selling Stockholder with respect to the
offering contemplated hereby except the obligations expressly set forth in this
Agreement, (d) the Underwriters and their respective affiliates may be engaged
in a broad range of transactions that involve interests that differ from those
of each of the Company and each Selling Stockholder, and (e) the Underwriters
have not provided any legal, accounting, regulatory or tax advice with respect
to the offering contemplated hereby and the Company and each of the Selling
Stockholders has consulted its own respective legal, accounting, regulatory and
tax advisors to the extent it deemed appropriate. The Company and the Selling
Stockholders hereby waive any claims that the Company or the Selling
Stockholders may have against the Underwriters with respect to any breach of
fiduciary duty in connection with this offering.

         SECTION 14. Research Analyst Independence. The Company acknowledges
that the Underwriters' research analysts and research departments are required
to be independent from their respective investment banking divisions and are
subject to certain regulations and internal policies, and that such
Underwriters' research analysts may hold views and make statements or investment
recommendations and/or publish research reports with respect to the Company
and/or the offering that


                                      -27-
<PAGE>


differ from the views of their respective investment banking divisions. The
Company and the Selling Stockholders hereby waive and release, to the fullest
extent permitted by law, any claims that the Company or the Selling Stockholders
may have against the Underwriters with respect to any conflict of interest that
may arise from the fact that the views expressed by their independent research
analysts and research departments may be different from or inconsistent with the
views or advice communicated to the Company or the Selling Stockholders by such
Underwriters' investment banking divisions. The Company and the Selling
Stockholders acknowledge that each of the Underwriters is a full-service
securities firm and as such from time to time, subject to applicable securities
laws, may effect transactions for its own account or the account of its
customers and hold long or short positions in debt or equity securities of the
companies that may be the subject of the transactions contemplated by this
Agreement.

         SECTION 15. Parties. This Agreement shall each inure to the benefit of
and be binding upon the Underwriters, the Company and the Selling Stockholders
and their respective successors. Nothing expressed or mentioned in this
Agreement is intended or shall be construed to give any person, firm or
corporation, other than the Underwriters, the Company and the Selling
Stockholders and their respective successors and the controlling persons and
officers and directors referred to in Sections 6 and 7 and their heirs and legal
representatives, any legal or equitable right, remedy or claim under or in
respect of this Agreement or any provision herein contained. This Agreement and
all conditions and provisions hereof are intended to be for the sole and
exclusive benefit of the Underwriters, the Company and the Selling Stockholders
and their respective successors, and said controlling persons and officers and
directors and their heirs and legal representatives, and for the benefit of no
other person, firm or corporation. No purchaser of Securities from any
Underwriter shall be deemed to be a successor by reason merely of such purchase.

         SECTION 16. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

         SECTION 17. TIME. TIME SHALL BE OF THE ESSENCE OF THIS AGREEMENT.
EXCEPT AS OTHERWISE SET FORTH HEREIN, SPECIFIED TIMES OF DAY REFER TO NEW YORK
CITY TIME.

         SECTION 18. Counterparts. This Agreement may be executed in any number
of counterparts, each of which shall be deemed to be an original, but all such
counterparts shall together constitute one and the same Agreement.

         SECTION 19. Effect of Headings. The Section headings herein are for
convenience only and shall not affect the construction hereof.


                                      -28-
<PAGE>


         If the foregoing is in accordance with your understanding of our
agreement, please sign and return to the Company, the Founder and the
Attorney-in-Fact for the Selling Stockholders a counterpart hereof, whereupon
this instrument, along with all counterparts, will become a binding agreement
among the Underwriters, the Company, the Founder and the Selling Stockholders in
accordance with its terms.


                                    Very truly yours,

                                    IPG PHOTONICS CORPORATION


                                    By
                                         ---------------------------------------
                                         Title:


                                    Valentin P. Gapontsev


                                    --------------------------------------------


                                    By
                                         ---------------------------------------
                                         As Attorney-in-Fact acting on behalf of
                                         the Selling Stockholders named in
                                         Schedule B hereto


CONFIRMED AND ACCEPTED,
   as of the date first above written:


MERRILL LYNCH, PIERCE, FENNER & SMITH
  INCORPORATED


By
    ----------------------------------
           Authorized Signatory


LEHMAN BROTHERS INC.


By
    ----------------------------------
           Authorized Signatory


                                      -29-
<PAGE>


For themselves and as Representatives of the other Underwriters named in
Schedule A hereto.


                                      -30-
<PAGE>


                                   SCHEDULE A


<Table>
<Caption>
                                                               Number of
Name of Underwriter                                         Initial Securities
-------------------------------------------------------     ------------------
<S>                                                         <C>
Merrill Lynch, Pierce, Fenner & Smith Incorporated.....
Lehman Brothers Inc. ..................................
Needham & Company, LLC.................................
Jefferies & Co.........................................
Thomas Weisel Partners, LLC............................
                                                            ------------------
         Total.........................................
                                                            ==================
</Table>


<PAGE>


                                   SCHEDULE B


<Table>
<Caption>
                                Number of Initial              Number of Option             Maximum Number of
                              Securities to be Sold         Securities to Be Sold         Securities to Be Sold
                              ---------------------         ---------------------         ---------------------
<S>                           <C>                           <C>                           <C>
IPG PHOTONICS CORPORATION



Total....................
</Table>


<PAGE>


                                   SCHEDULE C

                            IPG PHOTONICS CORPORATION
                             Shares of Common Stock
                          (Par Value $0.0001 Per Share)

1. The initial public offering price per share for the Securities, determined as
provided in said Section 2, shall be $.

2. The purchase price per share for the Securities to be paid by the several
Underwriters shall be $, being an amount equal to the initial public offering
price set forth above less $ per share; provided that the purchase price per
share for any Option Securities purchased upon the exercise of the overallotment
option described in Section 2(b) shall be reduced by an amount per share equal
to any dividends or distributions declared by the Company and payable on the
Initial Securities but not payable on the Option Securities.


<PAGE>


                                   SCHEDULE D

                          [List of persons and entities
                               subject to lock-up]


<PAGE>


                                   SCHEDULE E

            [SPECIFY EACH ISSUER GENERAL USE FREE WRITING PROSPECTUS]

<PAGE>


                                                                     Exhibit A-1

                      FORM OF OPINION OF COMPANY'S COUNSEL
                    TO BE DELIVERED PURSUANT TO SECTION 5(b)

                  (i) The Company is a corporation validly existing and in good
         standing under the laws of the State of Delaware.

                  (ii) The Company has corporate power and authority to own,
         lease and operate its properties and to conduct its business as
         described in the Prospectus and to enter into and perform its
         obligations under the Underwriting Agreement.

                  (iii) The Company is duly qualified as a foreign corporation
         to transact business and is in good standing in each jurisdiction in
         which such qualification is required, whether by reason of the
         ownership or leasing of property or the conduct of business, except
         where the failure so to qualify or to be in good standing would not
         result in a Material Adverse Effect.

                  (iv) The authorized, issued and outstanding capital stock of
         the Company is as set forth in the Prospectus in the column entitled
         "Actual" under the caption "Capitalization" (except for subsequent
         issuances, if any, pursuant to the Underwriting Agreement or pursuant
         to reservations, agreements or employee benefit plans referred to in
         the Prospectus or pursuant to the exercise of convertible securities or
         options referred to in the Prospectus); the shares of issued and
         outstanding capital stock of the Company, including the Securities to
         be purchased by the Underwriters from the Selling Stockholders, have
         been duly authorized and validly issued and are fully paid and
         non-assessable; and none of the outstanding shares of capital stock of
         the Company was issued in violation of the preemptive or other similar
         rights of any securityholder of the Company.

                  (v) The Securities to be purchased by the Underwriters from
         the Company have been duly authorized for issuance and sale to the
         Underwriters pursuant to the Underwriting Agreement and, when issued
         and delivered by the Company pursuant to the Underwriting Agreement
         against payment of the consideration set forth in the Underwriting
         Agreement, will be validly issued and fully paid and non-assessable and
         no holder of the Securities is or will be subject to personal liability
         by reason of being such a holder.

                  (vi) The issuance of the Securities to be purchased by the
         Underwriters from the Company is not subject to the preemptive or other
         similar rights of any securityholder of the Company.

                  (vii) Each Subsidiary is a corporation validly existing and in
         good standing under the laws of the jurisdiction of its incorporation,
         has corporate power and authority to own, lease and operate its
         properties and to conduct its business as described in the Prospectus
         and is duly qualified as a foreign corporation to transact business and
         is in good standing in each jurisdiction in which such qualification is
         required, whether by reason of the ownership or leasing of property or
         the conduct of business, except where the failure so to qualify or to
         be in good standing would not result in a Material Adverse Effect;
         except as otherwise disclosed in the Registration Statement, all of the
         issued and outstanding capital stock of each Subsidiary has been duly
         authorized and validly issued, is fully paid and non-assessable and, to
         our knowledge, is owned by the Company, directly or through
         subsidiaries, subject to no security interest, other encumbrance or
         adverse claim; to our knowledge none of the outstanding shares of
         capital stock



<PAGE>
                                                                     Exhibit A-1
                                                                          Page 2


         of any Subsidiary was issued in violation of the preemptive or similar
         rights of any securityholder of such Subsidiary.

                  (viii) The Underwriting Agreement has been duly authorized,
         executed and delivered by the Company.

                  (ix) The Registration Statement, including any Rule 462(b)
         Registration Statement, has been declared effective under the 1933 Act;
         any required filing of the Prospectus pursuant to Rule 424(b) has been
         made in the manner and within the time period required by Rule 424(b)
         (without reference to Rule 424(b)(8)); any required filing of each
         Issuer Free Writing Prospectus pursuant to Rule 433 has been made in
         the manner and within the time period required by Rule 433(d); and, to
         our knowledge, no stop order suspending the effectiveness of the
         Registration Statement or any Rule 462(b) Registration Statement has
         been issued under the 1933 Act and no proceedings for that purpose have
         been instituted or are pending or threatened by the Commission.

                  (x) The Registration Statement, including any Rule 462(b)
         Registration Statement and the Rule 430A Information, the Prospectus
         and each amendment or supplement to the Registration Statement and
         Prospectus, as of their respective effective or issue dates (other than
         the financial statements and supporting schedules included therein or
         omitted therefrom, as to which we need express no opinion) complied as
         to form in all material respects with the requirements of the 1933 Act
         and the 1933 Act Regulations.

                  (xi) The form of certificate used to evidence the Common Stock
         complies in all material respects with all applicable statutory
         requirements, with any applicable requirements of the charter and
         bylaws of the Company and the requirements of the Nasdaq Global Market.

                  (xii) To our knowledge, there is not pending or threatened any
         action, suit, proceeding, inquiry or investigation, to which the
         Company or any subsidiary is a party, or to which the property of the
         Company or any subsidiary is subject, before or brought by any court or
         governmental agency or body, domestic or foreign, which would
         reasonably be expected to result in a Material Adverse Effect, or which
         would reasonably be expected to materially and adversely affect the
         properties or assets thereof or the consummation of the transactions
         contemplated in the Underwriting Agreement or the performance by the
         Company of its obligations thereunder.

                  (xiii) The information in the Prospectus under
         "Business--Facilities," "Business--Legal Proceedings," "Description of
         Capital Stock--Common Stock," "Description of Capital Stock--Preferred
         Stock" and "Certain Material U.S. Federal Income Tax Consequences to
         Non-U.S. Holders" and in the Registration Statement under Item 14, to
         the extent that it constitutes a summary of matters of law, the
         Company's charter and bylaws or legal proceedings, or legal
         conclusions, is accurate in all material respects.

                  (xiv) All descriptions in the Registration Statement of
         contracts and other documents to which the Company or its subsidiaries
         are a party are accurate in all material respects; to our knowledge,
         there are no contracts, indentures, mortgages, loan agreements, notes,
         leases or other instruments required to be described or referred to in
         the Registration Statement or to be filed as



<PAGE>
                                                                     Exhibit A-1
                                                                          Page 3


         exhibits to the Registration Statement other than those described or
         referred to therein or filed as exhibits thereto.

                  (xv) No filing with, or authorization, approval, consent,
         license, order, registration, qualification or decree of, any court or
         governmental authority or agency, domestic or foreign (other than under
         the 1933 Act and the 1933 Act Regulations, which have been obtained, or
         as may be required under the securities or Blue Sky laws of the various
         states, as to which we express no opinion) is necessary or required in
         connection with the due authorization, execution and delivery of the
         Underwriting Agreement or for the offering, issuance, sale or delivery
         of the Securities.

                  (xvi) The execution, delivery and performance of the
         Underwriting Agreement and the consummation of the transactions
         contemplated in the Underwriting Agreement and in the Registration
         Statement (including the issuance and sale of the Securities to be
         purchased by the Underwriters from the Company and the use of the
         proceeds from the sale of the Securities by the Company as described in
         the Prospectus under the caption "Use of Proceeds") and compliance by
         the Company with its obligations under the Underwriting Agreement do
         not and will not, whether with or without the giving of notice or lapse
         of time or both, conflict with or constitute a breach of, or default or
         Repayment Event (as defined in Section 1(a)(xi) of the Underwriting
         Agreement) under or result in the creation or imposition of any lien,
         charge or encumbrance upon any property or assets of the Company or any
         subsidiary pursuant to any contract, indenture, mortgage, deed of
         trust, loan or credit agreement, note, lease or any other agreement or
         instrument, known to us, to which the Company or any subsidiary is a
         party or by which it or any of them may be bound, or to which any of
         the property or assets of the Company or any subsidiary is subject
         (except for such conflicts, breaches, defaults or Repayment Events or
         liens, charges or encumbrances that would not have a Material Adverse
         Effect), nor will such action result in any violation of the provisions
         of the charter or bylaws of the Company or any subsidiary, or any
         applicable law, statute, rule, regulation, judgment, order, writ or
         decree, known to us, of any government, government instrumentality or
         court, domestic or foreign, having jurisdiction over the Company or any
         subsidiary or any of their respective properties, assets or operations.

                  (xvii) Except as otherwise disclosed in the Registration
         Statement and the Prospectus, to our knowledge, there are no persons
         with registration rights or other similar rights to have any securities
         registered pursuant to the Registration Statement or otherwise
         registered by the Company under the 1933 Act.

                  (xviii) The Company is not required, and upon the issuance and
         sale of the Securities to be purchased by the Underwriters from the
         Company as herein contemplated and the application of the net proceeds
         therefrom as described in the Prospectus will not be required, to
         register as an "investment company" under the 1940 Act.

         Nothing has come to our attention that would lead us to believe that
the Registration Statement or any amendment thereto, including the Rule 430A
Information (except for financial statements and schedules and other financial
data included or omitted therefrom, as to which we express no belief), at the
time such Registration Statement or any such amendment became effective,
contained an untrue statement of a material fact or omitted to state a material
fact required to be stated therein or necessary to make the



<PAGE>
                                                                     Exhibit A-1
                                                                          Page 4


statements therein not misleading or that the Prospectus or any amendment or
supplement thereto (except for financial statements and schedules and other
financial data included therein or omitted therefrom, as to which we express no
belief), at the time the Prospectus was issued, at the time any such amended or
supplemented prospectus was issued or at the Closing Time, included or includes
an untrue statement of a material fact or omitted or omits to state a material
fact necessary in order to make the statements therein, in the light of the
circumstances under which they were made, not misleading. In addition, nothing
has come to our attention that would lead us to believe that the documents
included in the General Disclosure Package, other than the financial statements
and schedules and other financial data included or incorporated by reference
therein or omitted therefrom, as to which we express no belief, as of the
Applicable Time, contained any untrue statement of a material fact or omitted to
state any material fact necessary in order to make the statements therein, in
the light of circumstances under which they were made, not misleading. With
respect to statements contained in the General Disclosure Package, any statement
contained in any of the constituent documents shall be deemed to be modified or
superseded to the extent that any information contained in subsequent
constituent documents modifies or replaces such statement.

         In rendering such opinion, such counsel may rely, as to matters of fact
(but not as to legal conclusions), to the extent they deem proper, on
certificates of responsible officers of the Company and public officials. Such
opinion shall not state that it is to be governed or qualified by, or that it is
otherwise subject to, any treatise, written policy or other document relating to
legal opinions, including, without limitation, the Legal Opinion Accord of the
ABA Section of Business Law (1991).



<PAGE>


                                                                     Exhibit A-2

                        FORM OF OPINION OF PATENT COUNSEL
                    TO BE DELIVERED PURSUANT TO SECTION 5(b)


(i) The information in the Registration Statement and the Prospectus under the
captions "Risk Factors -- We are subject to lawsuits alleging that we are
infringing third-party intellectual property rights. Intellectual property
claims could result in costly litigation and harm our business" and "Business --
Legal Proceedings" are accurate and complete statements or summaries of the
matters therein set forth, and nothing has come to our attention that causes us
to believe that such material contains any untrue statement of a material fact,
or omits to state a material fact that is required to be stated therein or
necessary in order to make the statements made therein not misleading or
incomplete.



<PAGE>


                                                                       Exhibit B

             FORM OF OPINION OF COUNSEL FOR THE SELLING STOCKHOLDERS
                    TO BE DELIVERED PURSUANT TO SECTION 5(c)

         (i) No filing with, or consent, approval, authorization, license,
order, registration, qualification or decree of, any court or governmental
authority or agency, domestic or foreign, (other than the issuance of the order
of the Commission declaring the Registration Statement effective and such
authorizations, approvals or consents as may be necessary under state securities
laws, as to which we need express no opinion) is necessary or required to be
obtained by the Selling Stockholders for the performance by each Selling
Stockholder of its obligations under the Underwriting Agreement or in the Power
of Attorney and Custody Agreement, or in connection with the offer, sale or
delivery of the Securities.

         (ii) Each Power of Attorney and Custody Agreement has been duly
authorized, executed and delivered by the respective Selling Stockholders and
constitutes the valid and binding agreement of such Selling Stockholder.

         (iii) The Underwriting Agreement has been duly authorized, executed and
delivered by or on behalf of each Selling Stockholder.

         (iv) The Attorney-in-Fact has been duly authorized by the Selling
Stockholders to deliver the Securities on behalf of the Selling Stockholders in
accordance with the terms of the Underwriting Agreement.

         (v) The execution, delivery and performance of the Underwriting
Agreement and the Power of Attorney and Custody Agreement and the sale and
delivery of the Securities and the consummation of the transactions contemplated
in the Underwriting Agreement and in the Registration Statement and compliance
by the Selling Stockholders with its obligations under the Underwriting
Agreement have been duly authorized by all necessary action on the part of the
Selling Stockholders and do not and will not, whether with or without the giving
of notice or passage of time or both, conflict with or constitute a breach of,
or default under or result in the creation or imposition of any tax, lien,
charge or encumbrance upon the Securities or any property or assets of the
Selling Stockholders pursuant to, any contract, indenture, mortgage, deed of
trust, loan or credit agreement, note, license, lease or other instrument or
agreement to which any Selling Stockholder is a party or by which they may be
bound, or to which any of the property or assets of the Selling Stockholders may
be subject nor will such action result in any violation of the provisions of the
charter or bylaws of the Selling Stockholders, if applicable, or any law,
administrative regulation, judgment or order of any governmental agency or body
or any administrative or court decree having jurisdiction over such Selling
Stockholder or any of its properties.

         (vi) Each of the Selling Stockholders has valid title to, or a valid
security entitlement in respect of, the Securities to be sold by such Selling
Stockholder free and clear of all security interests, claims, liens, equities
and other encumbrances, and each of the Selling Stockholders has the legal right
and power, and all authorization and approval required by law, to enter into
this Agreement and the Power of Attorney and Custody Agreement of such Selling
Stockholder and to sell, transfer and deliver the Securities to be sold by such
Selling Stockholder.

         (vii) Upon the Underwriters' acquiring possession of stock certificates
representing the Securities to be sold by the Selling Stockholders, endorsed to
the Underwriters and paying the purchase price therefor pursuant to this
Agreement, the Underwriters (assuming that no such Underwriter has



<PAGE>
                                                                       Exhibit B
                                                                          Page 2


notice of any "adverse claim," within the meaning of Section 8-105 of the New
York Uniform Commercial Code, to such Securities) will acquire their respective
interests in such Securities (including, without limitation, all rights that
such Selling Stockholder had or has the power to transfer in such Securities)
free and clear of any adverse claim within the meaning of Section 8-102 of the
New York Uniform Commercial Code.

         (viii) Upon payment of the purchase price for the Securities to be sold
by such Selling Stockholder pursuant to this Agreement, delivery of such
Securities, as directed by the Underwriters, to Cede or such other nominee as
may be designated by DTC, registration of such Securities in the name of Cede or
such other nominee and the crediting of such Securities on the books of DTC to
securities accounts of the Underwriters (assuming that neither DTC nor any such
Underwriter has notice of any "adverse claim," within the meaning of Section
8-105 of the UCC, to such Securities), (A) DTC shall be a "protected purchaser,"
within the meaning of Section 8-303 of the UCC, of such Securities and will
acquire its interest in the Securities (including, without limitation, all
rights that such Selling Stockholder had or has the power to transfer in such
Securities) free and clear of any adverse claim within the meaning of Section
8-102 of the UCC, (B) under Section 8-501 of the UCC, the Underwriters will
acquire a valid security entitlement in respect of such Securities and (C) no
action (whether framed in conversion, replevin, constructive trust, equitable
lien, or other theory) based on any "adverse claim," within the meaning of
Section 8-102 of the UCC, to such Securities may be asserted against the
Underwriters with respect to such security entitlement; for purposes of this
representation, such Selling Stockholder may assume that when such payment,
delivery and crediting occur, (x) such Securities will have been registered in
the name of Cede or another nominee designated by DTC, in each case on the
Company's share registry in accordance with its certificate of incorporation,
bylaws and applicable law, (y) DTC will be registered as a "clearing
corporation," within the meaning of Section 8-102 of the UCC, and (z)
appropriate entries to the accounts of the several Underwriters on the records
of DTC will have been made pursuant to the UCC.



<PAGE>


                                                                       Exhibit C

                            FORM OF LOCK-UP AGREEMENT



<PAGE>



                                SCHEDULE 1(b)(xi)

         Selling Stockholders affiliated with a member firm of the NASD

    1.  Merrill Lynch Taurus Fund 2000, L.P.
    2.  ML IBK Positions, Inc.
    3.  Merrill Lynch Ventures L.P. 2001
    4.  Merrill Lynch KECALP L.P. 1999
    5.  KECALP Inc., as Nominee for Merrill Lynch KECALP International L.P. 1999



