1
                                                                     Exhibit 1.1

                                12,500,000 Shares

                                   LEXENT INC.

                     COMMON STOCK, PAR VALUE $.001 PER SHARE

                             UNDERWRITING AGREEMENT

                                                                   June __, 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 12,500,000 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 1,875,000 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 674,615 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 hereinafter referred to as the "INITIAL
         REGISTRATION
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         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 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.
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                  (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 organized and
         is an existing limited liability company in good standing under the
         laws of the jurisdiction of its incorporation, 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 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 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 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.
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                  (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.

                  (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,
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         "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.

                  (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.
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                  (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.

                  (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
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         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 $___________ 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 __________, 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 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
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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) 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.,
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         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 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
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                                                                              11


         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 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 and (iv) 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.
   12
                                                                              12


                  (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 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
   13
                                                                              13


         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 statements 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 statements and summary of earnings for them
                           to be in conformity with generally accepted
                           accounting principles;

                                    (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;
   14
                                                                              14


                           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) the information set forth in the Registration
                  Statement under the captions "Prospectus Summary--Lexent
                  Inc.", "--The Offering", "--Summary Consolidated Financial
                  Data", "Risk Factors", "Use of Proceeds", "Dividend Policy",
                  "Capitalization", "Dilution", "Selected Consolidated Financial
                  Data", "Management's Discussion and Analysis of Financial
                  Condition and Results of Operations", "Business",
                  "Management", "Certain Relationships and Related Transactions"
                  and "Description of Capital Stock", which is expressed in
                  dollars (or percentages derived from such dollar amounts) and
                  has been obtained from accounting records which are subject to
                  controls over financial reporting or which has been derived
                  directly from such accounting records by analysis or
                  computation, is in agreement with such records or computations
                  made therefrom.

                           (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 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)
   15
                                                                              15


         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.

                  (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 ____________,
                  __________ and _______, those being the only states in which
                  the ownership or lease of property or the conduct of its
                  business requires such qualification;

                           (ii) Each subsidiary of the Company has been duly
                  incorporated and is an existing corporation in good standing
                  under the laws of the jurisdiction of its incorporation, with
                  power and authority (corporate and other) to own its
                  properties and conduct its business as described in the
                  Prospectus; and each
   16
                                                                              16


                  subsidiary of the Company is duly qualified to do business as
                  a foreign corporation in good standing in ____________,
                  __________ and _______, those being the only states in which
                  the ownership or lease of property or the conduct of its
                  business requires such qualification; 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 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;

                           (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 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;
   17
                                                                              17


                           (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 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.
   18
                                                                              18


                  (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 Agreement"), from each
         of the executive officers, directors and shareholders 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. (a) 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
   19
                                                                              19


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.

         (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."
   20
                                                                              20


         (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 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
   21
                                                                              21


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.

         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.
   22
                                                                              22


         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
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.
   23
                                                                              23



         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__________________________________
                                                Name:
                                                 Title:

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___________________________________________
              Name:
              Title:
   24
                                   SCHEDULE A



                                UNDERWRITER                                              FIRM SECURITIES
                                -----------                                              ---------------
                                                                                      
Credit Suisse First Boston Corporation......................................
Chase Securities Inc........................................................
Raymond James & Associates, Inc.............................................
                                                                                         ---------------
         Total..............................................................
                                                                                         ===============


   25
                                   SCHEDULE B

                     PARTIES DELIVERING A LOCK-UP AGREEMENT


DIRECTORS AND EXECUTIVE OFFICERS



STOCKHOLDERS
   26
                                    EXHIBIT A

                            FORM OF LOCK-UP AGREEMENT

                                                                  ________, 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
   27
                  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 [insert -- six months after the Lock-Up Agreement
is signed], 2000.

                                             Very truly yours,


                                             ___________________________________
                                             Name:


                                       A-2