EXHIBIT 10.1

                                6,000,000 Shares


                                   LEXENT INC.


                     Common Stock, par value $.001 per share


                             UNDERWRITING AGREEMENT

                                                                   July 27, 2000

CREDIT SUISSE FIRST BOSTON CORPORATION
CHASE SECURITIES INC.
RAYMOND JAMES & ASSOCIATES, INC.

  As Representatives of the Several Underwriters,
    c/o Credit Suisse First Boston Corporation,
         Eleven Madison Avenue,
         New York, N.Y. 10010-3629

Dear Sirs:

          1. Introductory. Lexent Inc., a Delaware corporation ("Company"),
proposes to issue and sell 6,000,000 shares ("Firm Securities") of its Common
Stock, par value $.001 per share ("Securities") and also proposes to issue and
sell to the Underwriters, at the option of the Underwriters, an aggregate of not
more than 900,000 additional shares ("Optional Securities") of its Securities as
set forth below. The Firm Securities and the Optional Securities are herein
collectively called the "Offered Securities". As part of the offering
contemplated by this Agreement, Credit Suisse First Boston Corporation (the
"Designated Underwriter") has agreed to reserve out of the Firm Securities
purchased by it under this Agreement, up to 823,333 shares, for sale to the
Company's directors, officers, employees and other parties associated with the
Company (collectively, "Participants"), as set forth in the Prospectus (as
defined herein) under the heading "Underwriting" (the "Directed Share Program").
The Firm Securities to be sold by the Designated Underwriter pursuant to the
Directed Share Program (the "Directed Shares") will be sold by the Designated
Underwriter pursuant to this Agreement at the public offering price. Any
Directed Shares not subscribed for by the end of the business day on which this
Agreement is executed will be offered to the public by the Underwriters as set
forth in the Prospectus. The Company hereby agrees with the several Underwriters
named in Schedule A hereto ("Underwriters") as follows:

          2. Representations and Warranties of the Company. The Company
represents and warrants to, and agrees with, the several Underwriters that:

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     (a) A registration statement (No. 333_30660) relating to the Offered
Securities, including a form of prospectus, has been filed with the Securities
and Exchange Commission ("Commission") and either (i) has been declared
effective under the Securities Act of 1933 ("Act") and is not proposed to be
amended or (ii) is proposed to be amended by amendment or post_effective
amendment. If such registration statement ("initial registration statement") has
been declared effective, either (i) an additional registration statement
("additional registration statement") relating to the Offered Securities may
have been filed with the Commission pursuant to Rule 462(b) ("Rule 462(b)")
under the Act and, if so filed, has become effective upon filing pursuant to
such Rule and the Offered Securities all have been duly registered under the Act
pursuant to the initial registration statement and, if applicable, the
additional registration statement or (ii) such an additional registration
statement is proposed to be filed with the Commission pursuant to Rule 462(b)
and will become effective upon filing pursuant to such Rule and upon such filing
the Offered Securities will all have been duly registered under the Act pursuant
to the initial registration statement and such additional registration
statement. If the Company does not propose to amend the initial registration
statement or if an additional registration statement has been filed and the
Company does not propose to amend it, and if any post_effective amendment to
either such registration statement has been filed with the Commission prior to
the execution and delivery of this Agreement, the most recent amendment (if any)
to each such registration statement has been declared effective by the
Commission or has become effective upon filing pursuant to Rule 462(c) ("Rule
462(c)") under the Act or, in the case of the additional registration statement,
Rule 462(b). For purposes of this Agreement, "Effective Time" with respect to
the initial registration statement or, if filed prior to the execution and
delivery of this Agreement, the additional registration statement means (i) if
the Company has advised the Representatives that it does not propose to amend
such registration statement, the date and time as of which such registration
statement, or the most recent post_effective amendment thereto (if any) filed
prior to the execution and delivery of this Agreement, was declared effective by
the Commission or has become effective upon filing pursuant to Rule 462(c), or
(ii) if the Company has advised the Representatives that it proposes to file an
amendment or post_effective amendment to such registration statement, the date
and time as of which such registration statement, as amended by such amendment
or post_effective amendment, as the case may be, is declared effective by the
Commission. If an additional registration statement has not been filed prior to
the execution and delivery of this Agreement but the Company has advised the
Representatives that it proposes to file one, "Effective Time" with respect to
such additional registration statement means the date and time as of which such
registration statement is filed and becomes effective pursuant to Rule 462(b).
"Effective Date" with respect to the initial registration statement or the
additional registration statement (if any) means the date of the Effective Time
thereof. The initial registration statement, as amended at its Effective Time,
including all information contained in the additional registration statement (if
any) and deemed to be a part of the initial registration statement as of the
Effective Time of the additional registration statement pursuant to the General
Instructions of the Form on which it is filed and including all information (if
any) deemed to be a part of the initial registration statement as of its
Effective Time pursuant to Rule 430A(b) ("Rule 430A(b)") under the Act, is

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hereinafter referred to as the "Initial Registration Statement". The additional
registration statement, as amended at its Effective Time, including the contents
of the initial registration statement incorporated by reference therein and
including all information (if any) deemed to be a part of the additional
registration statement as of its Effective Time pursuant to Rule 430A(b), is
hereinafter referred to as the "Additional Registration Statement". The Initial
Registration Statement and the Additional Registration Statement are herein
referred to collectively as the "Registration Statements" and individually as a
"Registration Statement". The form of prospectus relating to the Offered
Securities, as first filed with the Commission pursuant to and in accordance
with Rule 424(b) ("Rule 424(b)") under the Act or (if no such filing is
required) as included in a Registration Statement, is hereinafter referred to as
the "Prospectus". No document has been or will be prepared or distributed in
reliance on Rule 434 under the Act.

     (b) If the Effective Time of the Initial Registration Statement is prior to
the execution and delivery of this Agreement: (i) on the Effective Date of the
Initial Registration Statement, the Initial Registration Statement conformed in
all material respects to the requirements of the Act and the rules and
regulations of the Commission ("Rules and Regulations") and did not include any
untrue statement of a material fact or omit to state any material fact required
to be stated therein or necessary to make the statements therein not misleading,
(ii) on the Effective Date of the Additional Registration Statement (if any),
each Registration Statement conformed, or will conform, in all material respects
to the requirements of the Act and the Rules and Regulations and did not
include, or will not include, any untrue statement of a material fact and did
not omit, or will not omit, to state any material fact required to be stated
therein or necessary to make the statements therein not misleading and (iii) on
the date of this Agreement, the Initial Registration Statement and, if the
Effective Time of the Additional Registration Statement is prior to the
execution and delivery of this Agreement, the Additional Registration Statement
each conforms, and at the time of filing of the Prospectus pursuant to Rule
424(b) or (if no such filing is required) at the Effective Date of the
Additional Registration Statement in which the Prospectus is included, each
Registration Statement and the Prospectus will conform, in all material respects
to the requirements of the Act and the Rules and Regulations, and neither of
such documents includes, or will include, any untrue statement of a material
fact or omits, or will omit, to state any material fact required to be stated
therein or necessary to make the statements therein not misleading. If the
Effective Time of the Initial Registration Statement is subsequent to the
execution and delivery of this Agreement: on the Effective Date of the Initial
Registration Statement, the Initial Registration Statement and the Prospectus
will conform in all material respects to the requirements of the Act and the
Rules and Regulations, neither of such documents will include any untrue
statement of a material fact or will omit to state any material fact required to
be stated therein or necessary to make the statements therein not misleading,
and no Additional Registration Statement has been or will be filed. The two
preceding sentences do not apply to statements in or omissions from a
Registration Statement or the Prospectus based upon written information
furnished to the Company by any Underwriter

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through the Representatives specifically for use therein, it being understood
and agreed that the only such information is that described as such in Section
7(b) hereof.

     (c) The Company has been duly incorporated and is an existing corporation
in good standing under the laws of the State of Delaware, with power and
authority (corporate and other) to own its properties and conduct its business
as described in the Prospectus; and the Company is duly qualified to do business
as a foreign corporation in good standing in all other jurisdictions in which
its ownership or lease of property or the conduct of its business requires such
qualification, except where the failure to be so qualified would not have a
material adverse effect on the condition (financial or other), business,
properties or results of operations of the Company and its subsidiaries taken as
a whole (a "Material Adverse Effect").

     (d) Each subsidiary of the Company has been duly incorporated or organized,
as the case may be, and is an existing corporation or limited liability company,
as the case may be, in good standing under the laws of the jurisdiction of its
incorporation or organization, with power and authority (corporate and other) to
own its properties and conduct its business as described in the Prospectus; and
each subsidiary of the Company is duly qualified to do business as a foreign
corporation or limited liability company, as the case may be, in good standing
in all other jurisdictions in which its ownership or lease of property or the
conduct of its business requires such qualification, except where the failure to
be so qualified would not have a Material Adverse Effect; and all of the issued
and outstanding ownership interests of each subsidiary of the Company has been
duly authorized and validly issued; and all the ownership interests of each
subsidiary are owned directly by the Company and, except as described in the
Prospectus, are free from liens, encumbrances and defects.

     (e) The Offered Securities and all other outstanding shares of capital
stock of the Company have been duly authorized; all outstanding shares of
capital stock of the Company are, and, when the Offered Securities have been
delivered and paid for in accordance with this Agreement on each Closing Date
(as defined below), such Offered Securities will have been, validly issued,
fully paid and nonassessable and will conform to the description thereof
contained in the Prospectus; and the stockholders of the Company have no
preemptive rights arising by operation of law, under the Company's certificate
of incorporation or by-laws or otherwise with respect to the Securities.

     (f) Except as disclosed in the Prospectus, there are no contracts,
agreements or understandings between the Company and any person that would give
rise to a valid claim against the Company or any Underwriter for a brokerage
commission, finder's fee or other like payment in connection with this offering.

     (g) Except for the Registration Rights Agreement, dated as of July 23,
1998, between the Company and the investors named therein, there are no
contracts, agreements or understandings between the Company and any person
granting such person the right to require the Company to file a registration
statement under the Act with respect to any

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securities of the Company owned or to be owned by such person or to require the
Company to include such securities in the securities registered pursuant to a
Registration Statement or in any securities being registered pursuant to any
other registration statement filed by the Company under the Act.

     (h) The Offered Securities have been approved for listing on the Nasdaq
Stock Market's National Market.

     (i) No consent, approval, authorization, or order of, or filing with, any
governmental agency or body or any court is required for the consummation of the
transactions contemplated by this Agreement in connection with the issuance and
sale of the Offered Securities by the Company, except such as have been obtained
and made under the Act or as may be required under state securities laws.

     (j) The execution, delivery and performance of this Agreement, and the
issuance and sale of the Offered Securities will not result in a breach or
violation of any of the terms and provisions of, or constitute a default under,
any statute, any rule, regulation or order of any governmental agency or body or
any court, domestic or foreign, having jurisdiction over the Company or any
subsidiary of the Company or any of their properties, or any agreement or
instrument to which the Company or any such subsidiary is a party or by which
the Company or any such subsidiary is bound or to which any of the properties of
the Company or any such subsidiary is subject, or the charter or by_laws of the
Company or certificate of formation or limited liability company agreement of
any such subsidiary, and the Company has full power and authority to authorize,
issue and sell the Offered Securities as contemplated by this Agreement.

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

     (l) Except as disclosed in the Prospectus, the Company and its subsidiaries
have good and marketable title to all real properties and all other properties
and assets owned by them, in each case free from liens, encumbrances and defects
that would materially affect the value thereof or materially interfere with the
use made or to be made thereof by them; and except as disclosed in the
Prospectus, the Company and its subsidiaries hold any leased real or personal
property under valid and enforceable leases with no exceptions that would
materially interfere with the use made or to be made thereof by them.

     (m) The Company and its subsidiaries possess adequate certificates,
authorities or permits issued by appropriate governmental agencies or bodies
necessary to conduct the business now operated by them and have not received any
notice of proceedings relating to the revocation or modification of any such
certificate, authority or permit that, if determined adversely to the Company or
any of its subsidiaries, would individually or in the aggregate have a Material
Adverse Effect.

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     (n) No labor dispute with the employees of the Company or any subsidiary
exists or, to the knowledge of the Company, is imminent that might have a
Material Adverse Effect.

     (o) The Company and its subsidiaries own, possess or can acquire on
reasonable terms, adequate trademarks, trade names and other rights to
inventions, know_how, patents, copyrights, confidential information and other
intellectual property (collectively, "intellectual property rights") necessary
to conduct the business now operated by them, or presently employed by them, and
have not received any notice of infringement of or conflict with asserted rights
of others with respect to any intellectual property rights that, if determined
adversely to the Company or any of its subsidiaries, would individually or in
the aggregate have a Material Adverse Effect.

     (p) Except as disclosed in the Prospectus, neither the Company nor any of
its subsidiaries is in violation of any statute, any rule, regulation, decision
or order of any governmental agency or body or any court, domestic or foreign,
relating to the use, disposal or release of hazardous or toxic substances or
relating to the protection or restoration of the environment or human exposure
to hazardous or toxic substances (collectively, "environmental laws"), owns or
operates any real property contaminated with any substance that is subject to
any environmental laws, is liable for any off_site disposal or contamination
pursuant to any environmental laws, or is subject to any claim relating to any
environmental laws, which violation, contamination, liability or claim would
individually or in the aggregate have a Material Adverse Effect; and the Company
is not aware of any pending investigation which might lead to such a claim.

     (q) Except as disclosed in the Prospectus, there are no pending actions,
suits or proceedings against or affecting the Company, any of its subsidiaries
or any of their respective properties that, if determined adversely to the
Company or any of its subsidiaries, would individually or in the aggregate have
a Material Adverse Effect, or would materially and adversely affect the ability
of the Company to perform its obligations under this Agreement, or which are
otherwise material in the context of the sale of the Offered Securities; and no
such actions, suits or proceedings are threatened or, to the Company's
knowledge, contemplated.

     (r) The financial statements included in each Registration Statement and
the Prospectus present fairly the financial position of the Company and its
consolidated subsidiaries as of the dates shown and their results of operations
and cash flows for the periods shown, and such financial statements have been
prepared in conformity with the generally accepted accounting principles in the
United States applied on a consistent basis; and the assumptions used in
preparing the pro forma financial statements included in each Registration
Statement and the Prospectus provide a reasonable basis for presenting the
significant effects directly attributable to the transactions or events
described therein, the related pro forma adjustments give appropriate effect to
those assumptions, and the pro forma columns therein reflect the proper
application of those adjustments to the corresponding historical financial
statement amounts.

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     (s) Except as disclosed in the Prospectus, since the date of the latest
audited financial statements included in the Prospectus there has been no
material adverse change, nor any development or event involving a prospective
material adverse change, in the condition (financial or other), business,
properties or results of operations of the Company and its subsidiaries taken as
a whole, and, except as disclosed in or contemplated by the Prospectus, there
has been no dividend or distribution of any kind declared, paid or made by the
Company on any class of its capital stock.

     (t) Furthermore, the Company represents and warrants to the Underwriters
that (i) the Registration Statement, the Prospectus and any preliminary
prospectus comply, and any further amendments or supplements thereto will
comply, with any applicable laws or regulations of foreign jurisdictions in
which the Prospectus or any preliminary prospectus, as amended or supplemented,
if applicable, are distributed in connection with the Directed Share Program,
and that (ii) no authorization, approval, consent, license, order, registration
or qualification of or with any government, governmental instrumentality or
court, other than such as have been obtained, is necessary under the securities
law and regulations of foreign jurisdictions in which the Directed Shares are
offered outside the United States.

     (u) The Company has not offered, or caused the Underwriters to offer, any
Offered Securities to any person pursuant to the Directed Share Program with the
specific intent to unlawfully influence (i) a customer or supplier of the
Company to alter the customer's or supplier's level or type of business with the
Company or (ii) a trade journalist or publication to write or publish favorable
information about the Company or its products.

     (v) The Company has the authorized, issued and outstanding capitalization
as of December 31, 1999 set forth in the prospectus under the heading
"Capitalization".

     (w) There are no parties that have rights to register any securities of the
Company, other than Allegra Capital Partners III, L.P., Allegra Capital Partners
IV, L.P. and Abbott Capital 1330 Investors I, L.P., each of which has waived
such rights by executing the Lock-Up Agreement dated the date hereof,
substantially in the form of Exhibit A attached hereto.

     (x) The Company maintains a system of internal accounting controls
sufficient to provide reasonable assurances that (i) transactions are executed
in accordance with management's general or specific authorization; (ii)
transactions are recorded as necessary to permit preparation of financial
statements in conformity with generally accepted accounting principles and to
maintain accountability for assets; (iii) access to assets is permitted only in
accordance with management's general or specific authorization; and (iv) the
recorded accountability for assets is compared with existing assets at
reasonable intervals and appropriate action is taken with respect to any
differences.

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     (y) All material tax returns required to be filed by the Company and any of
its subsidiaries in any jurisdiction have been filed or have properly been
extended, and all material taxes, including withholding taxes, penalties and
interest, assessments, fees and other charges due pursuant to such returns or
pursuant to any assessment received by the Company or any of its subsidiaries
have been paid, other than those which are being contested in good faith and for
which adequate reserves have been provided. There are no transfer taxes or other
similar fees or charges under federal law or the laws of any state, or any
political subdivision thereof, required to be paid in connection with the
execution and delivery of this Agreement by the Company or the issuance by the
Company or the sale by the Company of the Offered Securities, except for fees or
charges that may be required to be paid in connection with applicable blue sky
laws, which fees and charges the Company hereby agrees to pay.

     (z) PricewaterhouseCoopers LLC are independent public accountants with
respect to the Company and its subsidiaries as required by the Act and the Rules
and Regulations.

     (aa) The statements in the Prospectus under the heading "Certain
Relationships and Related Transactions" set forth all existing agreements,
arrangements, understanding or transactions, or proposed agreements,
arrangements, understandings or transactions, between or among the Company, on
the one hand, and any officer, director or stockholder of the Company, or with
any partner, affiliate or associate of any of the forgoing persons or entities,
on the other hand, required to be set forth or described thereunder.

     (bb) The Company is not and, after giving effect to the offering and sale
of the Offered Securities and the application of the proceeds thereof as
described in the Prospectus, will not be, an "investment company" or a company
"controlled" by and "investment company" as such term is defined in the
Investment Company Act of 1940, as amended, and the rules and regulations of the
Commission thereunder.

          3. Purchase, Sale and Delivery of Offered Securities. On the basis of
the representations, warranties and agreements herein contained, but subject to
the terms and conditions herein set forth, the Company agrees to sell to the
Underwriters, and the Underwriters agree, severally and not jointly, to purchase
from the Company, at a purchase price of $13.95 per share, the respective
numbers of shares of Firm Securities set forth opposite the names of the
Underwriters in Schedule A hereto.

          The Company will deliver the Firm Securities to the Representatives
for the accounts of the Underwriters, against payment of the purchase price in
Federal (same day) funds by official bank check or checks or wire transfer to an
account at a bank acceptable to Credit Suisse First Boston Corporation ("CSFBC")
drawn to the order of the Company at the office of Simpson Thacher & Bartlett,
at 10:00 A.M., New York time, on August 2, 2000, or at such other time not later
than seven full business days thereafter as CSFBC and the Company determine,
such time being herein referred to as the "First Closing Date". For purposes of
Rule 15c6-1 under the Securities Exchange Act of 1934, the First Closing Date
(if later than the otherwise applicable settlement date) shall be the settlement
date for payment of funds and delivery of

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     securities for all the Offered Securities sold pursuant to the offering.
     The Firm Securities so to be delivered will be in definitive form, in such
     denominations and registered in such names as CSFBC requests and will be
     made available for checking and packaging at the above office of Simpson
     Thacher & Bartlett at least 24 hours prior to the First Closing Date.

          In addition, upon written notice from CSFBC given to the Company from
time to time not more than 30 days subsequent to the date of the Prospectus, the
Underwriters may purchase all or less than all of the Optional Securities at the
purchase price per Security to be paid for the Firm Securities. The Company
agrees to sell to the Underwriters the number of shares of Optional Securities
specified in such notice and the Underwriters agree, severally and not jointly,
to purchase such Optional Securities. Such Optional Securities shall be
purchased for the account of each Underwriter in the same proportion as the
number of shares of Firm Securities set forth opposite such Underwriter's name
bears to the total number of shares of Firm Securities (subject to adjustment by
CSFBC to eliminate fractions) and may be purchased by the Underwriters only for
the purpose of covering over_allotments made in connection with the sale of the
Firm Securities. No Optional Securities shall be sold or delivered unless the
Firm Securities previously have been, or simultaneously are, sold and delivered.
The right to purchase the Optional Securities or any portion thereof may be
exercised from time to time and to the extent not previously exercised may be
surrendered and terminated at any time upon notice by CSFBC to the Company.

          Each time for the delivery of and payment for the Optional Securities,
being herein referred to as an "Optional Closing Date", which may be the First
Closing Date (the First Closing Date and each Optional Closing Date, if any,
being sometimes referred to as a "Closing Date"), shall be determined by CSFBC
but shall be not later than five full business days after written notice of
election to purchase Optional Securities is given. The Company will deliver the
Optional Securities being purchased on each Optional Closing Date to the
Representatives for the accounts of the several Underwriters, against payment of
the purchase price therefor in Federal (same day) funds by official bank check
or checks or wire transfer to an account at a bank acceptable to CSFBC drawn to
the order of the Company, at the above office of Simpson Thacher & Bartlett. The
certificates for the Optional Securities being purchased on each Optional
Closing Date will be in definitive form, in such denominations and registered in
such names as CSFBC requests upon reasonable notice prior to such Optional
Closing Date and will be made available for checking and packaging at the above
office of Simpson Thacher & Bartlett at a reasonable time in advance of such
Optional Closing Date.

          4. Offering by Underwriters. It is understood that the several
Underwriters propose to offer the Offered Securities for sale to the public as
set forth in the Prospectus.

          5. Certain Agreements of the Company. The Company agrees with the
several Underwriters that:

          (a) If the Effective Time of the Initial Registration Statement is
     prior to the execution and delivery of this Agreement, the Company will
     file the Prospectus with the Commission pursuant to and in accordance with
     subparagraph (1) (or, if applicable and if consented to by CSFBC,
     subparagraph (4)) of Rule 424(b) not later than the earlier of (A)

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     the second business day following the execution and delivery of this
     Agreement or (B) the fifteenth business day after the Effective Date of the
     Initial Registration Statement. The Company will advise CSFBC promptly of
     any such filing pursuant to Rule 424(b). If the Effective Time of the
     Initial Registration Statement is prior to the execution and delivery of
     this Agreement and an additional registration statement is necessary to
     register a portion of the Offered Securities under the Act but the
     Effective Time thereof has not occurred as of such execution and delivery,
     the Company will file the additional registration statement or, if filed,
     will file a post_effective amendment thereto with the Commission pursuant
     to and in accordance with Rule 462(b) on or prior to 10:00 P.M., New York
     time, on the date of this Agreement or, if earlier, on or prior to the time
     the Prospectus is printed and distributed to any Underwriter, or will make
     such filing at such later date as shall have been consented to by CSFBC.

          (b) The Company will advise CSFBC promptly of any proposal to amend or
     supplement the initial or any additional registration statement as filed or
     the related prospectus or the Initial Registration Statement, the
     Additional Registration Statement (if any) or the Prospectus and will not
     effect such amendment or supplementation without CSFBC's consent; and the
     Company will also advise CSFBC promptly of the effectiveness of each
     Registration Statement (if its Effective Time is subsequent to the
     execution and delivery of this Agreement) and of any amendment or
     supplementation of a Registration Statement or the Prospectus and of the
     institution by the Commission of any stop order proceedings in respect of a
     Registration Statement and will use its best efforts to prevent the
     issuance of any such stop order and to obtain as soon as possible its
     lifting, if issued.

          (c) If, at any time when a prospectus relating to the Offered
     Securities is required to be delivered under the Act in connection with
     sales by any Underwriter or dealer, any event occurs as a result of which
     the Prospectus as then amended or supplemented would include an untrue
     statement of a material fact or omit to state any material fact necessary
     to make the statements therein, in the light of the circumstances under
     which they were made, not misleading, or if it is necessary at any time to
     amend the Prospectus to comply with the Act, the Company will promptly
     notify CSFBC of such event and will promptly prepare and file with the
     Commission, at its own expense, an amendment or supplement which will
     correct such statement or omission or an amendment which will effect such
     compliance. Neither CSFBC's consent to, nor the Underwriters' delivery of,
     any such amendment or supplement shall constitute a waiver of any of the
     conditions set forth in Section 6.

          (d) As soon as practicable, but not later than the Availability Date
     (as defined below), the Company will make generally available to its
     securityholders an earnings statement covering a period of at least 12
     months beginning after the Effective Date of the Initial Registration
     Statement (or, if later, the Effective Date of the Additional Registration
     Statement) which will satisfy the provisions of Section 11(a) of the Act.
     For the purpose of the preceding sentence, "Availability Date" means the
     45th day after the end of the fourth fiscal quarter following the fiscal
     quarter that includes such Effective Date, except

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     that, if such fourth fiscal quarter is the last quarter of the Company's
     fiscal year, "Availability Date" means the 90th day after the end of such
     fourth fiscal quarter.

          (e) The Company will furnish to the Representatives copies of each
     Registration Statement (four of which will be signed and will include all
     exhibits), each related preliminary prospectus, and, so long as a
     prospectus relating to the Offered Securities is required to be delivered
     under the Act in connection with sales by any Underwriter or dealer, the
     Prospectus and all amendments and supplements to such documents, in each
     case in such quantities as CSFBC requests. The Prospectus shall be so
     furnished on or prior to 3:00 P.M., New York time, on the business day
     following the later of the execution and delivery of this Agreement or the
     Effective Time of the Initial Registration Statement. All other documents
     shall be so furnished as soon as available. The Company will pay the
     expenses of printing and distributing to the Underwriters all such
     documents.

          (f) The Company will arrange for the qualification of the Offered
     Securities for sale under the laws of such jurisdictions as CSFBC
     designates and will continue such qualifications in effect so long as
     required for the distribution; provided, however, that in connection
     therewith the Company shall not be required to qualify as a foreign
     corporation or to file a general consent to service of process in any
     jurisdiction.

          (g) During the period of five years hereafter, the Company will
     furnish to the Representatives and, upon request, to each of the other
     Underwriters, as soon as practicable after the end of each fiscal year, a
     copy of its annual report to stockholders for such year; and the Company
     will furnish to the Representatives (i) as soon as available, a copy of
     each report and any definitive proxy statement of the Company filed with
     the Commission under the Securities Exchange Act of 1934 or mailed to
     stockholders, and (ii) from time to time, such other information concerning
     the Company as CSFBC may reasonably request.

          (h) The Company will pay all expenses incident to the performance of
     its obligations under this Agreement, for any filing fees and other
     expenses (including fees and disbursements of counsel) incurred in
     connection with qualification of the Offered Securities for sale under the
     laws of such jurisdictions as CSFBC designates, for the filing fee 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. ("NASD") of the Offered Securities, for any travel
     expenses of the Company's officers and employees and any other expenses of
     the Company in connection with attending or hosting meetings with
     prospective purchasers of the Offered Securities and for expenses incurred
     in distributing preliminary prospectuses and the Prospectus (including any
     amendments and supplements thereto) to the Underwriters.

          (i) For a period of 180 days after the date of the initial public
     offering of the Offered Securities, the Company will not offer, sell,
     contract to sell, announce its intention to sell, pledge or otherwise
     dispose of, directly or indirectly, or file with the Commission a
     registration statement under the Act relating to, any additional shares of
     its Securities or

<PAGE>
                                                                              12


     securities convertible into or exchangeable or exercisable for any shares
     of its Securities, or publicly disclose the intention to make any such
     offer, sale, pledge, disposition or filing, without the prior written
     consent of CSFBC, except (i) issuances of Securities pursuant to the
     conversion or exchange of the Company's preferred stock or the exercise of
     options, in each case outstanding on the date hereof, (ii) grants of stock
     options pursuant to stock option plans in effect on the date hereof and the
     issuance of securities pursuant to the exercise of such stock options,
     (iii) issuances of Securities to participants in any employee stock
     purchase plan in effect on the date hereof, (iv) issuances of Securities in
     connection with strategic acquisitions or alliances so long as the
     recipients of such Securities enter into the restrictions on the
     disposition of such Securities set forth in this Section 5(i) for the
     remainder of the 180-day period set forth in this Section 5(i) and (v)
     filings of registration statements on Form S-8 with the Commission
     registering the shares of Common Stock issuable under its stock option and
     employee stock purchase plans in effect on the date hereof.

          (j) The Company will (i) enforce the terms of each Lock-up Agreement
     (as hereinafter defined), and (ii) issue stop-transfer instructions to the
     transfer agent for the Securities with respect to any transaction or
     contemplated transaction that would constitute a breach of or default under
     the applicable Lock-up Agreement. In addition, except with the prior
     written consent of CSFBC, the Company agrees (i) not to amend or terminate,
     or waive any right under, any Lock-up Agreement, or take any other action
     that would directly or indirectly have the same effect as an amendment or
     termination, or waiver of any right under any Lock-up Agreement, that would
     permit the holder of any Securities, or any securities convertible into, or
     exercisable or exchangeable for, Securities, to make any short sale of,
     grant any option for the purchase of, or otherwise transfer or dispose of,
     any such Securities or other securities, prior to the expiration of the 180
     days after the date of the Prospectus, and (ii) not consent to any sale,
     short sale, grant of an option for the purchase of, or other disposition or
     transfer of shares of Securities, or securities convertible into or
     exercisable or exchangeable for Securities, subject to a Lock-Up Agreement.

          (k) In connection with the Directed Share Program, the Company will
     ensure that the Directed Shares will be restricted to the extent required
     by the NASD or the NASD rules from sale, transfer, assignment, pledge or
     hypothecation for a period of three months following the date of the
     effectiveness of the Registration Statement. The Designated Underwriter
     will notify the Company as to which Participants will need to be so
     restricted. The Company will direct the transfer agent to place stop
     transfer restrictions upon such securities for such period of time.

          (l) The Company will pay all fees and disbursements of counsel
     incurred by the Underwriters in connection with the Directed Share Program
     and stamp duties, similar taxes or duties or other taxes, if any, incurred
     by the underwriters in connection with the Directed Share Program.
     Furthermore, the company covenants with the Underwriters that the company
     will comply with all applicable securities and other applicable laws, rules
     and

<PAGE>
                                                                              13


     regulations in each foreign jurisdiction in which the Directed Shares are
     offered in connection with the Directed Share Program.

          6. Conditions of the Obligations of the Underwriters. The obligations
of the several Underwriters to purchase and pay for the Firm Securities on the
First Closing Date and the Optional Securities to be purchased on each Optional
Closing Date will be subject to the accuracy of the representations and
warranties on the part of the Company herein, to the accuracy of the statements
of Company officers made pursuant to the provisions hereof, to the performance
by the Company of its obligations hereunder and to the following additional
conditions precedent:

          (a) The Representatives shall have received a letter, dated the date
     of delivery thereof (which, if the Effective Time of the Initial
     Registration Statement is prior to the execution and delivery of this
     Agreement, shall be on or prior to the date of this Agreement or, if the
     Effective Time of the Initial Registration Statement is subsequent to the
     execution and delivery of this Agreement, shall be prior to the filing of
     the amendment or post_effective amendment to the registration statement to
     be filed shortly prior to such Effective Time), from PricewaterhouseCoopers
     LLP to the effect that they are independent accountants with respect to the
     Company within the meaning of the Securities Act of 1933 and the applicable
     rules and regulations thereunder adopted by the SEC and stating to the
     effect that:

               (i) in their opinion the financial statements examined by them
          and included in the Registration Statements comply as to form in all
          material respects with the applicable accounting requirements of the
          Act and the related published Rules and Regulations;

               (ii) they have performed the procedures specified by the American
          Institute of Certified Public Accountants for a review of interim
          financial information as described in Statement of Auditing Standards
          No. 71, Interim Financial Information, on the unaudited financial
          statements included in the Registration Statements;

               (iii) on the basis of the review referred to in clause (ii)
          above, a reading of the latest available interim financial data of the
          Company, inquiries of officials of the Company who have responsibility
          for financial and accounting matters and other specified procedures,
          nothing came to their attention that caused them to believe that:

                    (A) the unaudited financial data included in the
               Registration Statements do not comply as to form in all material
               respects with the applicable accounting requirements of the Act
               and the related published Rules and Regulations or any material
               modifications should be made to such unaudited financial data and
               summary of earnings for them to be stated on a basis
               substantially consistent with the audited financial statements
               included in the Registration Statement;

<PAGE>
                                                                              14


                    (B) at the date of the latest available balance sheet read
               by such accountants, or at a subsequent specified date not more
               than three business days prior to the date of this Agreement,
               there was any change in the capital stock or any increase in
               short_term indebtedness or long_term debt of the Company and its
               consolidated subsidiaries or, at the date of the latest available
               balance sheet read by such accountants, there was any decrease in
               consolidated net current assets or net assets, as compared with
               amounts shown on the latest balance sheet included in the
               Prospectus; or

                    (C) for the period from the closing date of the latest
               income statement included in the Prospectus to the closing date
               of the latest available income statement read by such accountants
               there were any decreases, as compared with the corresponding
               period of the previous year, in consolidated net revenues or net
               operating income or in the total or per share amounts of
               consolidated income before extraordinary items or net income;

               except in all cases set forth in clauses (A) and (B) above for
               changes, increases or decreases which the Prospectus discloses
               have occurred or may occur or which are described in such letter;
               and

               (iv) they have compared specified dollar amounts (or percentages
          derived from such dollar amounts) and other financial information
          contained in the Registration Statements (in each case to the extent
          that such dollar amounts, percentages and other financial information
          are derived from the general accounting records of the Company and its
          subsidiaries subject to the internal controls of the Company's
          accounting system or are derived directly from such records by
          analysis or computation) with the results obtained from inquiries, a
          reading of such general accounting records and other procedures
          specified in such letter and have found such dollar amounts,
          percentages and other financial information to be in agreement wish
          such results, except as otherwise specified in such letter.

               (v) they proved the arithmetic accuracy of the application of the
          pro forma adjustments to the historical amounts as set forth in the
          Registration Statement under the captions "Summary Consolidated
          Financial Data", "Capitalization", "Dilution" and "Management's
          Discussion and Analysis of Financial Condition and Results of
          Operations".

          For purposes of this subsection, (i) if the Effective Time of the
     Initial Registration Statement is subsequent to the execution and delivery
     of this Agreement, "Registration Statements" shall mean the initial
     registration statement as proposed to be amended by the amendment or
     post-effective amendment to be filed shortly prior to its Effective Time,
     (ii) if the Effective Time of the Initial Registration Statement is prior
     to the execution and delivery of this Agreement but the Effective Time of
     the Additional Registration is

<PAGE>
                                                                              15


     subsequent to such execution and delivery, "Registration Statements" shall
     mean the Initial Registration Statement and the additional registration
     statement as proposed to be filed or as proposed to be amended by the
     post-effective amendment to be filed shortly prior to its Effective Time,
     and (iii) "Prospectus" shall mean the prospectus included in the
     Registration Statements.

          (b) If the Effective Time of the Initial Registration Statement is not
     prior to the execution and delivery of this Agreement, such Effective Time
     shall have occurred not later than 10:00 P.M., New York time, on the date
     of this Agreement or such later date as shall have been consented to by
     CSFBC. If the Effective Time of the Additional Registration Statement (if
     any) is not prior to the execution and delivery of this Agreement, such
     Effective Time shall have occurred not later than 10:00 P.M., New York
     time, on the date of this Agreement or, if earlier, the time the Prospectus
     is printed and distributed to any Underwriter, or shall have occurred at
     such later date as shall have been consented to by CSFBC. If the Effective
     Time of the Initial Registration Statement is prior to the execution and
     delivery of this Agreement, the Prospectus shall have been filed with the
     Commission in accordance with the Rules and Regulations and Section 5(a) of
     this Agreement. Prior to such Closing Date, no stop order suspending the
     effectiveness of a Registration Statement shall have been issued and no
     proceedings for that purpose shall have been instituted or, to the
     knowledge of the Company or the Representatives, shall be contemplated by
     the Commission.

          (c) Subsequent to the execution and delivery of this Agreement, there
     shall not have occurred (i) any change, or any development or event
     involving a prospective change, in the condition (financial or other),
     business, properties or results of operations of the Company and its
     subsidiaries taken as one enterprise which, in the judgment of a majority
     in interest of the Underwriters including the Representatives, is material
     and adverse and makes it impractical or inadvisable to proceed with
     completion of the public offering or the sale of and payment for the
     Offered Securities; (ii) any downgrading in the rating of any debt
     securities or preferred stock of the Company by any "nationally recognized
     statistical rating organization" (as defined for purposes of Rule 436(g)
     under the Act), or any public announcement that any such organization has
     under surveillance or review its rating of any debt securities or preferred
     stock of the Company (other than an announcement with positive implications
     of a possible upgrading, and no implication of a possible downgrading, of
     such rating); (iii) any material suspension or material limitation of
     trading in securities generally on the New York Stock Exchange or the
     Nasdaq Stock Market's National Market, or any setting of minimum prices for
     trading on such exchange, or any suspension of trading of any securities of
     the Company on any exchange or in the over_the_counter market; (iv) any
     banking moratorium declared by U.S. Federal or New York authorities; or (v)
     any outbreak or escalation of major hostilities in which the United States
     is involved, any declaration of war by Congress or any other substantial
     national or international calamity or emergency if, in the judgment of a
     majority in interest of the Underwriters including the Representatives, the
     effect of any such outbreak, escalation, declaration, calamity or emergency
     makes it impractical or inadvisable to proceed with completion of the
     public offering or the sale of and payment for the Offered Securities.

<PAGE>
                                                                              16


          (d) The Representatives shall have received an opinion, dated such
     Closing Date, of Reboul, MacMurray, Hewitt, Maynard & Kristol, counsel for
     the Company, to the effect that:

               (i) The Company has been duly incorporated and is an existing
          corporation in good standing under the laws of the State of Delaware,
          with corporate power and authority to own its properties and conduct
          its business as described in the Prospectus; and the Company is duly
          qualified to do business as a foreign corporation in good standing in
          all other jurisdictions in which its ownership or lease of property or
          the conduct of its business requires such qualification, except where
          the failure to be so qualified would not have a Material Adverse
          Effect;

               (ii) Each subsidiary of the Company has been duly incorporated or
          organized, as the case my be, and is an existing corporation in good
          standing under the laws of the jurisdiction of its incorporation or
          organization, with power and authority (corporate and other) to own
          its properties and conduct its business as described in the
          Prospectus; and each subsidiary of the Company is duly qualified to do
          business as a foreign corporation or limited liability company, as the
          case may be, in good standing in all other jurisdictions in which its
          ownership or lease of property or the conduct of its business requires
          such qualification, except where the failure to be so qualified would
          not have a Material Adverse Effect; all of the issued and outstanding
          ownership interests of each subsidiary of the Company has been duly
          authorized and validly issued; and all the ownership interests of each
          subsidiary are owned directly by the Company and, except as described
          in the Prospectus, are free from liens, encumbrances and defects.

               (iii) The Offered Securities delivered on such Closing Date and
          all other outstanding shares of the Common Stock of the Company have
          been duly authorized and validly issued, are fully paid and
          nonassessable and conform to the description thereof contained in the
          Prospectus; and the stockholders of the Company have no preemptive
          rights arising by operation of law, under the Company's certificate of
          incorporation or bylaws or otherwise with respect to the Securities;

               (iv) Except for the Registration Rights Agreement, dated as of
          July 23, 1998, between the Company and the investors named therein,
          there are no contracts, agreements or understandings known to such
          counsel between the Company and any person granting such person the
          right to require the Company to file a registration statement under
          the Act with respect to any securities of the Company owned or to be
          owned by such person or to require the Company to include such
          securities in the securities registered pursuant to the Registration
          Statement or in any securities being registered pursuant to any other
          registration statement filed by the Company under the Act;

<PAGE>
                                                                              17


               (v) No consent, approval, authorization or order of, or filing
          with, any governmental agency or body or any court is required for the
          consummation of the transactions contemplated by this Agreement in
          connection with the issuance or sale of the Offered Securities by the
          Company, except such as have been obtained and made under the Act and
          such as may be required under state securities laws;

               (vi) The execution, delivery and performance of this Agreement
          and the issuance and sale of the Offered Securities will not result in
          a breach or violation of any of the terms and provisions of, or
          constitute a default under, any statute, any rule, regulation or order
          of any governmental agency or body or any court having jurisdiction
          over the Company or any subsidiary of the Company or any of their
          properties, or any agreement or instrument filed as an exhibit to the
          Registration Statement to which the Company or any such subsidiary is
          a party or by which the Company or any such subsidiary is bound or to
          which any of the properties of the Company or any such subsidiary is
          subject, or the charter or by_laws of the Company or certificate of
          formation or limited liability company agreement any such subsidiary,
          and the Company has full power and authority to authorize, issue and
          sell the Offered Securities as contemplated by this Agreement;

               (vii) The Initial Registration Statement was declared effective
          under the Act as of the date and time specified in such opinion, the
          Additional Registration Statement (if any) was filed and became
          effective under the Act as of the date and time (if determinable)
          specified in such opinion, the Prospectus either was filed with the
          Commission pursuant to the subparagraph of Rule 424(b) specified in
          such opinion on the date specified therein or was included in the
          Initial Registration Statement or the Additional Registration
          Statement (as the case may be), and, to the best of the knowledge of
          such counsel, no stop order suspending the effectiveness of a
          Registration Statement or any part thereof has been issued and no
          proceedings for that purpose have been instituted or are pending or
          contemplated under the Act, and each Registration Statement and the
          Prospectus, and each amendment or supplement thereto, as of their
          respective effective or issue dates, complied as to form in all
          material respects with the requirements of the Act and the Rules and
          Regulations; such counsel have no reason to believe that any part of a
          Registration Statement or any amendment thereto, as of its effective
          date or as of such Closing Date, contained any untrue statement of a
          material fact or omitted to state any material fact required to be
          stated therein or necessary to make the statements therein not
          misleading or that the Prospectus or any amendment or supplement
          thereto, as of its issue date or as of such Closing Date, 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 the circumstances under which they were made, not
          misleading; the descriptions in the Registration Statements and
          Prospectus of statutes, legal and governmental proceedings and
          contracts and other documents are accurate in all material respects
          and fairly present the information required to be shown; and such
          counsel do not know of any legal or governmental proceedings required
          to be described in a Registration Statement or the Prospectus which
          are not described as required or of any contracts or documents of a
          character required to be described in

<PAGE>
                                                                              18


          a Registration Statement or the Prospectus or to be filed as exhibits
          to a Registration Statement which are not described and filed as
          required; it being understood that such counsel need express no
          opinion as to the financial statements or other financial data
          contained in the Registration Statements or the Prospectus; and

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

          (e) The Representatives shall have received from Simpson Thacher &
     Bartlett, counsel for the Underwriters, such opinion or opinions, dated
     such Closing Date, with respect to the incorporation of the Company, the
     validity of the Offered Securities delivered on such Closing Date, the
     Registration Statements, the Prospectus and other related matters as the
     Representatives may require, and the Company shall have furnished to such
     counsel such documents as they request for the purpose of enabling them to
     pass upon such matters.

          (f) The Representatives shall have received a certificate, dated such
     Closing Date, of the President or any Vice President and a principal
     financial or accounting officer of the Company in which such officers, to
     the best of their knowledge after reasonable investigation, shall state
     that: the representations and warranties of the Company in this Agreement
     are true and correct; the Company has complied with all agreements and
     satisfied all conditions on its part to be performed or satisfied hereunder
     at or prior to such Closing Date; no stop order suspending the
     effectiveness of any Registration Statement has been issued and no
     proceedings for that purpose have been instituted or are contemplated by
     the Commission; the Additional Registration Statement (if any) satisfying
     the requirements of subparagraphs (1) and (3) of Rule 462(b) was filed
     pursuant to Rule 462(b), including payment of the applicable filing fee in
     accordance with Rule 111(a) or (b) under the Act, prior to the time the
     Prospectus was printed and distributed to any Underwriter; and, subsequent
     to the dates of the most recent financial statements in the Prospectus,
     there has been no material adverse change, nor any development or event
     involving a prospective material adverse change, in the condition
     (financial or other), business, properties or results of operations of the
     Company and its subsidiaries taken as a whole except as set forth in or
     contemplated by the Prospectus or as described in such certificate.

          (g) The Representatives shall have received a letter, dated such
     Closing Date, of PricewaterhouseCoopers LLC which meets the requirements of
     subsection (a) of this Section, except that the specified date referred to
     in such subsection will be a date not more than three days prior to such
     Closing Date for the purposes of this subsection.

          (h) On or prior to the date of this Agreement, the Representatives
     shall have received lockup letters, in the form attached hereto as Exhibit
     A (each, a "Lock-Up

<PAGE>
                                                                              19


     Agreement"), from each of the executive officers, directors, shareholders
     and optionholders of the Company identified on Schedule B attached hereto.

The Company will furnish the Representatives with such conformed copies of such
opinions, certificates, letters and documents as the Representatives reasonably
requests. CSFBC may in its sole discretion waive on behalf of the Underwriters
compliance with any conditions to the obligations of the Underwriters hereunder,
whether in respect of an Optional Closing Date or otherwise.

     7. Indemnification and Contribution. The Company will indemnify and hold
harmless each Underwriter, its partners, directors and officers and each person,
if any, who controls such Underwriter within the meaning of Section 15 of the
Act, against any losses, claims, damages or liabilities, joint or several, to
which such Underwriter may become subject, under the Act or otherwise, insofar
as such losses, claims, damages or liabilities (or actions in respect thereof)
arise out of or are based upon any untrue statement or alleged untrue statement
of any material fact contained in any Registration Statement, the Prospectus, or
any amendment or supplement thereto, or any related preliminary prospectus, or
arise out of or are based upon the omission or alleged omission to state therein
a material fact required to be stated therein or necessary to make the
statements therein not misleading, and will reimburse each Underwriter for any
legal or other expenses reasonably incurred by such Underwriter in connection
with investigating or defending any such loss, claim, damage, liability or
action as such expenses are incurred; provided, however, that the Company will
not be liable in any such case to the extent that any such loss, claim, damage
or liability arises out of or is based upon an untrue statement or alleged
untrue statement in or omission or alleged omission from any of such documents
in reliance upon and in conformity with written information furnished to the
Company by any Underwriter through the Representatives specifically for use
therein, it being understood and agreed that the only such information furnished
by any Underwriter consists of the information described as such in subsection
(b) below.

     The Company agrees to indemnify and hold harmless the Designated
Underwriter and each person, if any, who controls the Designated Underwriter
within the meaning of either Section 15 of the Securities Act or Section 20 of
the Exchange Act (the "Designated Entities"), from and against any and all
losses, claims, damages and liabilities (including, without limitation, any
legal or other expenses reasonably incurred in connection with defending or
investigating any such action or claim) (i) caused by any untrue statement or
alleged untrue statement of a material fact contained in any material prepared
by or with the consent of the Company for distribution to Participants in
connection with the Directed Share Program or caused by any omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading; (ii) caused by the
failure of any Participant to pay for and accept delivery of Directed Shares
that the Participant agreed to purchase; or (iii) related to, arising out of, or
in connection with the Directed Share Program, other than losses, claims,
damages or liabilities (or expenses relating thereto) that are finally
judicially determined to have resulted from the bad faith or gross negligence of
the Designated Entities.

<PAGE>
                                                                              20


     (b) Each Underwriter will severally and not jointly indemnify and hold
harmless the Company, its directors and officers and each person, if any who
controls the Company within the meaning of Section 15 of the Act, against any
losses, claims, damages or liabilities to which the Company may become subject,
under the Act or otherwise, insofar as such losses, claims, damages or
liabilities (or actions in respect thereof) arise out of or are based upon any
untrue statement or alleged untrue statement of any material fact contained in
any Registration Statement, the Prospectus, or any amendment or supplement
thereto, or any related preliminary prospectus, or arise out of or are based
upon the omission or the alleged omission to state therein a material fact
required to be stated therein or necessary to make the statements therein not
misleading, in each case to the extent, but only to the extent, that such untrue
statement or alleged untrue statement or omission or alleged omission was made
in reliance upon and in conformity with written information furnished to the
Company by such Underwriter through the Representatives specifically for use
therein, and will reimburse any legal or other expenses reasonably incurred by
the Company in connection with investigating or defending any such loss, claim,
damage, liability or action as such expenses are incurred, it being understood
and agreed that the only such information furnished by any Underwriter consists
of the following information in the Prospectus furnished on behalf of each
Underwriter: the concession and reallowance figures appearing in the fourth
paragraph and last paragraph under the caption "Underwriting."

     (c) Promptly after receipt by an indemnified party under this Section of
notice of the commencement of any action, such indemnified party will, if a
claim in respect thereof is to be made against the indemnifying party under
subsection (a) or (b) above, notify the indemnifying party of the commencement
thereof; but the omission so to notify the indemnifying party will not relieve
it from any liability which it may have to any indemnified party otherwise than
under subsection (a) or (b) above. In case any such action is brought against
any indemnified party and it notifies the indemnifying party of the commencement
thereof, the indemnifying party will be entitled to participate therein and, to
the extent that it may wish, jointly with any other indemnifying party similarly
notified, to assume the defense thereof, with counsel satisfactory to such
indemnified party (who shall not, except with the consent of the indemnified
party, be counsel to the indemnifying party), and after notice from the
indemnifying party to such indemnified party of its election so to assume the
defense thereof, the indemnifying party will not be liable to such indemnified
party under this Section for any legal or other expenses subsequently incurred
by such indemnified party in connection with the defense thereof other than
reasonable costs of investigation. Notwithstanding anything contained herein to
the contrary, if indemnity may be sought pursuant to the last paragraph in
Section 7 (a) hereof in respect of such action or proceeding, then in addition
to such separate firm for the indemnified parties, the indemnifying party shall
be liable for the reasonable fees and expenses of not more than one separate
firm (in addition to any local counsel) for the Designated Underwriter for the
defense of any losses, claims, damages and liabilities arising out of the
Directed Share Program, and all persons, if any, who control the Designated
Underwriter within the meaning of either Section 15 of the Act of Section 20 of
the Exchange Act. No indemnifying party shall, without the prior written consent
of the indemnified party, effect any settlement of any pending or threatened
action in respect of which any indemnified party is or could have been a party
and indemnity could have been sought hereunder by such indemnified party unless
such settlement (i) includes an unconditional release of such indemnified party
from all liability on any claims that are the subject matter of such action

<PAGE>
                                                                              21


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 an indemnified party.

     (d) If the indemnification provided for in this Section is unavailable or
insufficient to hold harmless an indemnified party under subsection (a) or (b)
above, then each indemnifying party shall contribute to the amount paid or
payable by such indemnified party as a result of the losses, claims, damages or
liabilities referred to in subsection (a) or (b) above (i) in such proportion as
is appropriate to reflect the relative benefits received by the Company on the
one hand and the Underwriters on the other from the offering of the Securities
or (ii) if the allocation provided by clause (i) above is not permitted by
applicable law, in such proportion as is appropriate to reflect not only the
relative benefits referred to in clause (i) above but also the relative fault of
the Company on the one hand and the Underwriters on the other in connection with
the statements or omissions which resulted in such losses, claims, damages or
liabilities as well as any other relevant equitable considerations. The relative
benefits received by the Company on the one hand and the Underwriters on the
other shall be deemed to be in the same proportion as the total net proceeds
from the offering (before deducting expenses) received by the Company bear to
the total underwriting discounts and commissions received by the Underwriters.
The relative fault shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or the
omission or alleged omission to state a material fact relates to information
supplied by the Company or the Underwriters and the parties' relative intent,
knowledge, access to information and opportunity to correct or prevent such
untrue statement or omission. The amount paid by an indemnified party as a
result of the losses, claims, damages or liabilities referred to in the first
sentence of this subsection (d) shall be deemed to include any legal or other
expenses reasonably incurred by such indemnified party in connection with
investigating or defending any action or claim which is the subject of this
subsection (d). Notwithstanding the provisions of this subsection (d), 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
such untrue or alleged untrue statement or omission or alleged omission. No
person guilty of fraudulent misrepresentation (within the meaning of Section
11(f) of the Act) shall be entitled to contribution from any person who was not
guilty of such fraudulent misrepresentation. The Underwriters' obligations in
this subsection (d) to contribute are several in proportion to their respective
underwriting obligations and not joint.

     (e) The obligations of the Company under this Section shall be in addition
to any liability which the Company may otherwise have and shall extend, upon the
same terms and conditions, to each person, if any, who controls any Underwriter
within the meaning of the Act; and the obligations of the Underwriters under
this Section shall be in addition to any liability which the respective
Underwriters may otherwise have and shall extend, upon the same terms and
conditions, to each director of the Company, to each officer of the Company who
has signed a Registration Statement and to each person, if any, who controls the
Company within the meaning of the Act.

<PAGE>
                                                                              22


     8. Default of Underwriters. If any Underwriter or Underwriters default in
their obligations to purchase Offered Securities hereunder on either the First
or any Optional Closing Date and the aggregate number of shares of Offered
Securities that such defaulting Underwriter or Underwriters agreed but failed to
purchase does not exceed 10% of the total number of shares of Offered Securities
that the Underwriters are obligated to purchase on such Closing Date, CSFBC may
make arrangements satisfactory to the Company for the purchase of such Offered
Securities by other persons, including any of the Underwriters, but if no such
arrangements are made by such Closing Date, the non-defaulting Underwriters
shall be obligated severally, in proportion to their respective commitments
hereunder, to purchase the Offered Securities that such defaulting Underwriters
agreed but failed to purchase on such Closing Date. If any Underwriter or
Underwriters so default and the aggregate number of shares of Offered Securities
with respect to which such default or defaults occur exceeds 10% of the total
number of shares of Offered Securities that the Underwriters are obligated to
purchase on such Closing Date and arrangements satisfactory to CSFBC and the
Company for the purchase of such Offered Securities by other persons are not
made within 36 hours after such default, this Agreement will terminate without
liability on the part of any non-defaulting Underwriter or the Company, except
as provided in Section 9 (provided that if such default occurs with respect to
Optional Securities after the First Closing Date, this Agreement will not
terminate as to the Firm Securities or any Optional Securities purchased prior
to such termination). As used in this Agreement, the term "Underwriter" includes
any person substituted for an Underwriter under this Section. Nothing herein
will relieve a defaulting Underwriter from liability for its default.

     9. Survival of Certain Representations and Obligations. The respective
indemnities, agreements, representations, warranties and other statements of the
Company or its officers and of the several Underwriters set forth in or made
pursuant to this Agreement will remain in full force and effect, regardless of
any investigation, or statement as to the results thereof, made by or on behalf
of any Underwriter, the Company or any of their respective representatives,
officers or directors or any controlling person, and will survive delivery of
and payment for the Offered Securities. If this Agreement is terminated pursuant
to Section 8 or if for any reason the purchase of the Offered Securities by the
Underwriters is not consummated, the Company shall remain responsible for the
expenses to be paid or reimbursed by it pursuant to Section 5 and the respective
obligations of the Company and the Underwriters pursuant to Section 7 shall
remain in effect, and if any Offered Securities have been purchased hereunder
the representations and warranties in Section 2 and all obligations under
Section 5 shall also remain in effect. If the purchase of the Offered Securities
by the Underwriters is not consummated for any reason other than solely because
of the termination of this Agreement pursuant to Section 8 or the occurrence of
any event specified in clause (iii), (iv) or (v) of Section 6(c), the Company
will reimburse the Underwriters for all out_of_pocket expenses (including fees
and disbursements of counsel) reasonably incurred by them in connection with the
offering of the Offered Securities.

     10. Notices. All communications hereunder will be in writing and, if sent
to the Underwriters, will be mailed, delivered or sent by facsimile transmission
and confirmed to the Representatives, c/o Credit Suisse First Boston
Corporation, Eleven Madison Avenue, New York, N.Y. 10010_3629, Attention:
Investment Banking Department--Transactions Advisory Group, or, if sent to the
Company, will be mailed, delivered or sent by facsimile transmission and

<PAGE>
                                                                              23


confirmed to it at Lexent Inc., 3 New York Plaza, New York, NY 10004, Attention:
Chief Operating Officer; provided, however, that any notice to an Underwriter
pursuant to Section 7 will be mailed, delivered or sent by facsimile
transmission and confirmed to such Underwriter.

     11. Successors. This Agreement will inure to the benefit of and be binding
upon the parties hereto and their respective successors and the officers and
directors and controlling persons referred to in Section 7, and no other person
will have any right or obligation hereunder.

     12. Representation of Underwriters. The Representatives will act for the
several Underwriters in connection with this financing, and any action under
this Agreement taken by the Representatives jointly or by CSFBC will be binding
upon all the Underwriters.

     13. 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.

     14. Applicable Law. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of New York, without regard to principles
of conflicts of laws.

     The Company hereby submits to the non-exclusive jurisdiction of the Federal
and state courts in the Borough of Manhattan in The City of New York in any suit
or proceeding arising out of or relating to this Agreement or the transactions
contemplated hereby.

<PAGE>
                                                                              24


     If the foregoing is in accordance with the Representatives' understanding
of our agreement, kindly sign and return to the Company one of the counterparts
hereof, whereupon it will become a binding agreement between the Company and the
several Underwriters in accordance with its terms.

                               Very truly yours,

                                              LEXENT INC.

                                              By  /s/ KEVIN M. O'KANE
                                                  --------------------------
                                                  Name: Kevin M. O'Kane
                                                  Title: Vice Chairman and
                                                         Chief Operating Officer

The foregoing Underwriting Agreement is hereby
confirmed and accepted as of the date first above
 written.

         CREDIT SUISSE FIRST BOSTON CORPORATION
         CHASE SECURITIES INC.
         RAYMOND JAMES & ASSOCIATES

         Acting on behalf of themselves and as the
         Representatives of the several Underwriters

         By    CREDIT SUISSE FIRST BOSTON CORPORATION


         By /s/ HAROLD W. BOGLE
            -------------------
            Name: Harold W. Bogle
            Title:   Managing Director

<PAGE>

                                   SCHEDULE A


               Underwriter                                       Firm Securities
               -----------                                       ---------------

Credit Suisse First Boston Corporation ......................      2,685,000

Chase Securities Inc. .......................................      1,611,000

Raymond James & Associates, Inc. ............................      1,074,000

E*Offering Corp. ............................................         90,000

Fahnestock & Co. Inc. .......................................         90,000

Invemed Associates LLC ......................................         90,000

Prudential Securities Incorporated ..........................         90,000

Sands Brothers & Co., Ltd. ..................................         90,000

Shields & Company ...........................................         90,000

H.G. Wellington & Co. Inc. ..................................         90,000
                                                                   ---------
      Total .................................................      6,000,000
                                                                   =========

<PAGE>

                                   SCHEDULE B

                     Parties Delivering a Lock-Up Agreement

Directors and Executive Officers
--------------------------------

Charles T. Christ
Peter O. Crisp
Victor P. DeJoy
Joseph Haines
Thomas W. Hallagan
Alf T. Hansen
Nancy T. Huson
Kevin M. O'Kane
Hugh J. O'Kane, Jr.
L. White Matthews III
Sidney A. Sayovitz
Richard L. Schwob
Richard W. Smith
Jonathan H. Stern
Walter C. Teagle III

Stockholders
------------

Abbott Capital 1330 Investors L.L.P.
Allegra Capital Partners III, L.P.
Allegra Capital Partners IV, L.P.
Denis J. O'Kane
Hugh J. O'Kane, Jr. Irrevocable Trust H
  dated January 2, 1999
Hugh J. O'Kane, Jr. Irrevocable Trust A
  dated January 2, 1999
Hugh J. O'Kane, Jr. Irrevocable Trust K
  dated January 2, 1999
Hugh J. O'Kane, Jr. Irrevocable Trust J
  dated January 2, 1999
Kevin M. O'Kane, Jr. Irrevocable Living Trust I
  dated January 2, 1999
Kevin M. O'Kane, Jr. Irrevocable Living Trust II
  dated January 2, 1999
Hugh J. O'Kane, Jr. 2000 Grantor Retained Annuity Trust
Alf T. Hansen 2000 Grantor Retained Annuity Trust
Victor P. DeJoy Trust
Nicholas A. DeJoy Trust
W. Clark Teagle, IV Rev Trust (70H338)

<PAGE>

Trust FBO Clifton D. Teagle
  dated December 29, 1981 (794050)
Trust FBO Janet W. Teagle
  dated December 18, 1984 (795084)

Haines Family Charitable Remainder Trust for the benefit of Robert Palumbo and
Nina Palumbo
Haines Family Charitable Remainder Trust for the benefit of Douglas Haines and
Dawn Haines
Haines Family Charitable Remainder Trust for the benefit of Marie Palumbo
Haines Family Charitable Remainder Trust for the benefit of Joseph Haines and
Michele Haines

Optionholders
-------------

Rif Haffar

<PAGE>

                                    EXHIBIT A
                            Form of Lock-Up Agreement


                                                                   July __, 2000

Lexent Inc.
Three New York Plaza
New York, NY  10004

Credit Suisse First Boston Corporation
Chase Securities Inc.
Raymond James & Associates, Inc.
As Representatives of the Several Underwriters,
c/o Credit Suisse First Boston Corporation,
    Eleven Madison Avenue
    New York, NY  10010-3629

Dear Sirs:

          As an inducement to the Underwriters to execute the Underwriting
Agreement, pursuant to which an offering will be made that is intended to result
in the establishment of a public market for the Common Stock, par value $.001
per share (the "Securities"), of Lexent Inc. (the "Company"), the undersigned, a
stockholder of the Company, hereby agrees that from the date hereof and until
180 days after the public offering date set forth on the final prospectus used
to sell the Securities (the "Public Offering Date") pursuant to the Underwriting
Agreement, the undersigned will not offer, sell, contract to sell, pledge or
otherwise dispose of, directly or indirectly, any shares of Securities or
securities convertible into or exchangeable or exercisable for any shares of
Securities, enter into a transaction which would have the same effect, or enter
into any swap, hedge or other arrangement that transfers, in whole or in part,
any of the economic consequences of ownership of the Securities, whether any
such aforementioned transaction is to be settled by delivery of the Securities
or such other securities, in cash or otherwise, or publicly disclose the
intention to make any such offer, sale, pledge or disposition, or to enter into
any such transaction, swap, hedge or other arrangement, without, in each case,
the prior written consent of Credit Suisse First Boston Corporation.
Furthermore, the undersigned hereby agrees that from the date hereof until 180
days after the Public Offering Date, the undersigned waives any and all
registration rights or similar rights with respect to any securities of the
Company under any agreement or understanding to which the undersigned is a
party.

          Any Securities received upon exercise of options granted to the
undersigned [insert for Allegra Capital Partners --, or Securities purchased
under the Directed Share Program (as defined in the Underwriting Agreement)]
will also be subject to this Agreement. Any Securities acquired by the
undersigned in the open market will not be subject to this Agreement. A transfer
of Securities to a family member or trust may be made, provided the transferee
agrees to be bound in writing by the terms of this Agreement.


                                      A-1

<PAGE>

          In furtherance of the foregoing, the Company and its transfer agent
and registrar are hereby authorized to decline to make any transfer of shares of
Securities if such transfer would constitute a violation or breach of this
Agreement.

          This Agreement shall be binding on the undersigned and the successors,
heirs, personal representatives and assigns of the undersigned. This Agreement
shall lapse and become null and void if the Public Offering Date shall not have
occurred on or before January __, 2001.

                                        Very truly yours,


                                        -------------------------------
                                        Name:


                                      A-2