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                                                                   Exhibit 10.10

                              EMPLOYMENT AGREEMENT

                  EMPLOYMENT AGREEMENT, dated as of December 23, 1999, by and
between LEXENT INC., a Delaware corporation (the "Company"), and RIF K. HAFFAR
(the "Employee").

                              W I T N E S S E T H:

                  WHEREAS the Company desires to induce the Employee to enter
into employment with the Company for the period provided in this Agreement, and
the Employee is willing to accept such employment with the Company on a
full-time basis, all in accordance with the terms and conditions set forth
below;

                  NOW, THEREFORE, for and in consideration of the premises
hereof and the mutual covenants contained herein, the parties hereto hereby
covenant and agree as follows:


                  1.  Employment.

                  (a) The Company hereby agrees to employ the Employee, and the
         Employee hereby agrees to accept such employment with the Company,
         commencing on January 17, 1999 (the "Commencement Date") and continuing
         for the period set forth in Section 2 hereof, all upon the terms and
         conditions hereinafter set forth.

                  (b) The Employee affirms and represents that as of the
         commencement of his employment by the Company on the Commencement Date,
         he will be under no obligation to any former employer or other party
         which is in any way inconsistent with, or which imposes any restriction
         upon, the Employee's acceptance of employment hereunder with the
         Company, the employment of the Employee by the Company, or the
         Employee's undertakings under this Agreement. The Company acknowledges
         that the Employee and WinStar Wireless, Inc. have entered into a
         certain Separation and General Release Agreement, dated October 16,
         1999, pursuant to which the Employee has agreed to perform those
         services set forth in Schedule 1 hereto and the Company agrees that the
         Employee may provide such services so long as the performance thereof
         shall not violate any provision of this Agreement.

                  2. Term of Employment. Unless earlier terminated as provided
in this Agreement, the term of the Employee's employment under this Agreement
shall be for a period beginning on the Commencement Date and ending on January
17, 2004. The period from the Commencement Date until January 17, 2004, or, in
the event that the Employee's employment hereunder is earlier terminated as
provided herein, such shorter period, is hereinafter called the "Employment
Term"(the "Employment Term").

                  3. Duties. The Employee shall be employed as Executive Vice
President of the Company and Executive Vice President - Marketing & Business
Development of the Company's wholly-owned subsidiary, National Network
Technologies, LLC, a Delaware limited liability company ("NNT"), shall
faithfully perform and discharge such duties as inhere in the positions of
Executive Vice President of the Company and Executive Vice President - Marketing
& Business Development of NNT as may be specified in the By-laws of the Company
or the Limited Liability Company Agreement of NNT with respect to such
positions, and shall also perform and discharge such other duties and
responsibilities consistent with such position as the Board of Directors of the
Company (the "Board of Directors") shall from time to time determine. The
Employee shall report to the Chief Executive Officer of the Company. The
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Employee shall perform his duties principally at offices of the Company in New
York City, New York, with such travel to such other locations from time to time
as the Chief Executive Officer may reasonably prescribe. Except as may otherwise
be approved in advance by the Board of Directors, and except during vacation
periods and reasonable periods of absence due to sickness, personal injury or
other disability, the Employee shall devote his full business time throughout
the Employment Term to the services required of him hereunder. The Employee
shall render his business services exclusively to the Company and its
subsidiaries during the Employment Term and shall use his best efforts, judgment
and energy to improve and advance the business and interests of the Company and
its subsidiaries in a manner consistent with the duties of his positions.

                  4. Compensation.

                  (a) Salary. As compensation for the performance by the
         Employee of the services to be performed by the Employee hereunder
         during the Employment Term, the Company shall pay the Employee a base
         salary at the annual rate of Two Hundred and Forty Thousand Dollars
         ($240,000) (said amount, together with any increases thereto as may be
         determined from time to time by the Board of Directors in its sole
         discretion, being hereinafter referred to as "Salary"). Any Salary
         payable hereunder shall be paid in regular intervals in accordance with
         the Company's payroll practices from time to time in effect.

                  (b) Bonus. The Employee shall be eligible to receive bonus
         compensation from the Company in respect of each fiscal year (or
         portion thereof) occurring during the Employment Term in an amount
         targeted at 40% of his Salary (pro rated for any portion of a fiscal
         year occurring during the Employment Term) if the Company achieves the
         target performance objectives established by the Compensation Committee
         of the Board of Directors (the "Compensation Committee") with respect
         to such fiscal year. The Employee shall also be eligible to receive
         additional bonus compensation from the Company in respect of each
         fiscal year (or portion thereof) occurring during the Employment Term
         in an amount targeted at 60% of his Salary (prorated for any portion of
         a fiscal year occurring during the Employment Term) for exceptional
         performance as may be determined by the Compensation Committee in its
         sole discretion. In any event, the Employee shall be entitled to
         receive an aggregate bonus (not including the Relocation Payments
         referred to in (c) below) of not less than $100,000 in respect of the
         fiscal year ending December 31, 2000 (pro rated as aforesaid if the
         Employment Term ends prior to December 31, 2000).

                  (c) Relocation Payments. In addition to the compensation
         referred to in (a) and (b) above, the Employee shall also be eligible
         to receive one-time payments (the "Relocation Payments") consisting of
         (i) up to $24,000 for reimbursement of the Employee's expenses relating
         to his renting of an apartment in the New York City area for the first
         six months of the Employment Term, (ii) up to $10,000 for reimbursement
         of other reasonable expenses relating to the Employee's move to the New
         York City area and (iii) up to $10,000 for reimbursement of reasonable
         closing costs relating to the Employee's purchase of a home in the New
         York City area, in each case to be paid by the Company against
         submission of appropriate documentation by the Employee in accordance
         with the Company's standard policies.



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                  5. Other Benefits; Options.

                  (a) General. During the Employment Term, the Employee shall:

                           (i) be eligible to participate in employee fringe
         benefits and pension and/or profit sharing plans that may be provided
         by the Company for its senior executive employees in accordance with
         the provisions of such plans, as the same may be in effect from time to
         time;

                           (ii) be eligible to participate in any medical and
         health plans or other employee welfare benefit plans that may be
         provided by the Company for its senior executive employees in
         accordance with the provisions of any such plans, as the same may be in
         effect from time to time;

                           (iii) be entitled to the number of paid vacation days
         in each calendar year determined by the Company from time to time for
         its senior executive officers, provided that such number of paid
         vacation days in each calendar year shall not be less than fifteen (15)
         work days (three calendar weeks); the Employee shall also be entitled
         to all paid holidays given by the Company to its senior executive
         officers;

                           (iv) be entitled to sick leave, sick pay and
         disability benefits in accordance with any Company policy that may be
         applicable to senior executive employees from time to time; and

                           (v) be entitled to reimbursement for all reasonable
         and necessary out-of-pocket business expenses incurred by the Employee
         in the performance of his duties hereunder in accordance with the
         Company's normal policies from time to time in effect.

                  (b) Grant of Initial Options. In connection with the execution
         and delivery of this Agreement by the Employee, the Company is granting
         to the Employee options ("Initial Options") to purchase 250,000 shares
         of Company Common Stock, $.001 par value ("Common Stock"), at a
         purchase price of $10.00 per share, of which options to purchase 62,500
         shares of Common Stock shall vest immediately and options to purchase
         the remaining 187,500 shares of Common Stock will vest in thirty-six
         equal increments over the thirty-six month period beginning on the
         first anniversary of the Commencement Date, all as provided in the
         Stock Option Agreements of even date herewith between the Company and
         the Employee.

                  (c) Grant of Subsequent Options. In connection with his
         continued employment by the Company, on the first anniversary of the
         Commencement Date, and on each of the subsequent anniversaries thereof
         during the Employment Term, the Company agrees to grant the Employee
         options ("Subsequent Options") to purchase 10,000 shares of Common
         Stock at a purchase price equal to the Fair Market Value (as defined in
         (d) below) of the Common Stock on the date of grant, which options
         shall vest in twenty-five percent increments over a four-year period
         with the first twenty-five percent to vest on the first anniversary of
         the date of grant. Each grant of these Subsequent Options shall be
         pursuant to specific terms set forth in a stock option agreement
         between the Company and the Employee.

                  (d) Fair Market Value. "Fair Market Value" means as of any
         date, the value of Common Stock determined as follows:

                           (i) If the Common Stock is listed on any established
         stock exchange or a national market system, including without
         limitation the


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         National Market System of the National Association of Securities
         Dealers, Inc. Automated Quotation ("NASDAQ") System, the Fair Market
         Value of a share of Common Stock shall be the closing sales price for
         such stock (or the closing bid, if no sales were reported) as quoted on
         such system or exchange (or the exchange with the greatest volume of
         trading in Common Stock) on the last market trading day prior to the
         day of grant of the particular Subsequent Options and as reported in
         the Wall Street Journal or such other source as the Compensation
         Committee deems reliable;

                           (ii) If the Common Stock is quoted on the NASDAQ
         System (but not on the National Market System thereof) or is regularly
         quoted by a recognized securities dealer but selling prices are not
         reported, the Fair Market Value of a share of Common Stock shall be the
         average between the high bid and low asked prices for the Common Stock
         on the last market trading day prior to the day of grant of the
         particular Subsequent Options and as reported in the Wall Street
         Journal or such other source as the Compensation Committee deems
         reliable; or

                           (iii) In the absence of an established market for the
         Common Stock, the Fair Market Value shall be determined in good faith
         by the Compensation Committee.

                  6. Confidential Information. The Employee hereby covenants,
agrees and acknowledges as follows:

                  (a) The Employee has and will have access to and will
         participate in the development of or be acquainted with confidential or
         proprietary information and trade secrets related to the business of
         the Company and any present or future subsidiaries or affiliates of the
         Company (collectively with the Company, the "Companies"), including but
         not limited to (i) customer lists; related records and compilations of
         information; the identity, lists or descriptions of any new customers,
         referral sources or organizations; financial statements; cost reports
         or other financial information; contract proposals or bid ding
         information; business plans; training and operations methods and
         manuals; personnel records; software programs; reports and
         correspondence; and management systems, policies or procedures,
         including related forms and manuals; (ii) information pertaining to
         future developments such as future marketing or acquisition plans or
         ideas, and potential new business locations and (iii) all other
         tangible and intangible property, which are used in the business and
         operations of the Companies but not made public. The information and
         trade secrets relating to the business of the Companies described
         hereinabove in this paragraph (a) are hereinafter referred to
         collectively as the "Confidential Information", provided that the term
         Confidential Information shall not include any information (A) that is
         or becomes generally publicly available (other than as a result of
         violation of this Agreement by the Employee), (B) that the Employee
         receives on a nonconfidential basis from a source (other than the
         Companies or their representatives) that is not known by him to be
         bound by an obligation of secrecy or confidentiality to any of the
         Companies or (C) that was in the possession of the Employee prior to
         disclosure by the Companies.

                  (b) The Employee shall not disclose, use or make known for his
         or another's benefit any Confidential Information or use such
         Confidential Information in any way except as is in the best interests
         of the Companies in the performance of the Employee's duties under this
         Agreement. The Employee may disclose Confidential Information when
         required by a third party and applicable law or judicial process, but
         only after providing immediate notice to the Company of any third
         party's request for such information, which notice shall include the
         Employee's


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         intent to disclose any Confidential Information with respect to such
         request.

                  (c) The Employee acknowledges and agrees that a remedy at law
         for any breach or threatened breach of the provisions of this Section 6
         would be inadequate and, therefore, agrees that the Companies shall be
         entitled to seek injunctive relief in addition to any other available
         rights and remedies in case of any such breach or threatened breach by
         the Employee; provided, however, that nothing contained herein shall be
         construed as prohibiting the Companies from pursuing any other rights
         and remedies available for any such breach or threatened breach.

                  (d) The Employee agrees that upon termination of his
         employment with the Company for any reason, the Employee shall
         forthwith return to the Company all Confidential Information in
         whatever form maintained (including, without limitation, computer discs
         and other electronic media).

                  (e) The obligations of the Employee under this Section 6
         shall, except as otherwise provided herein, survive the termination of
         the Employment Term and the expiration or termination of this
         Agreement.

                  (f) Without limiting the generality of Section 12 hereof, the
         Employee hereby expressly agrees that the foregoing provisions of this
         Section 6 shall be binding upon the Employee's heirs, successors and
         legal representatives.

                  7. Termination of Employment.

                  (a) The Employee's employment hereunder shall be terminated
         upon the occurrence of any of the following:

                           (i) death of the Employee;

                           (ii) the Employee's inability to perform his duties
         on account of disability or incapacity for a period of one hundred
         eighty (180) or more days, whether or not consecutive, within any
         period of twelve (12) consecutive months;

                           (iii) the Company giving written notice, at any time,
         to the Employee that the Employee's employment is being terminated for
         "Cause" (as defined in (b) below);

                           (iv) the Company giving written notice, at any time,
         to the Employee that the Employee's employment is being terminated or
         is not being renewed, other than pursuant to clause (i), (ii) or (iii)
         above ("Without Cause");

                           (v) the Employee terminates his employment hereunder
         because the Company, solely due to an Executive Management Stockholder
         Block (as defined in (c) below), fails to consummate an initial public
         offering of its Common Stock within one (1) year of the Commencement
         Date; or

                           (vi) the Employee terminates his employment hereunder
         for any reason whatsoever (whether by reason of retirement, resignation
         or otherwise), other than in accordance with (v) above ("Without Good
         Reason").

                  (b) Cause. The following actions, failures and events by or
         affecting the Employee shall constitute "Cause" for termination within
         the meaning of clause (iii) of Section 7 (a) above:


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                           (i) an indictment for or conviction of the Employee
         of, or the entering of a plea of nolo contendere by the Employee with
         respect to, having committed a felony;

                           (ii) abuse of controlled substances or alcohol or
         acts of dishonesty or moral turpitude by the Employee that are
         detrimental to one or more of the Companies;

                           (iii) acts or omissions by the Employee that the
         Employee knew were likely to damage the business of one or more of the
         Companies;

                           (iv) negligence by the Employee in the performance
         of, or disregard by the Employee of, his material obligations under
         this Agreement or otherwise relating to his employment, which
         negligence or disregard continue unremedied for a period of fifteen
         (15) days after written notice thereof to the Employee; or

                           (v) failure by the Employee to obey the reasonable
         and lawful orders and policies of the Board of Directors that are
         consistent with the provisions of this Agree ment.

                  (c) Executive Management Stockholder Block. For purposes of
         this Agreement, an "Executive Management Stockholder Block" means the
         decision by the Company's Executive Management Stockholders (as that
         term is defined in the Stockholders Agreement, dated as of July 23,
         1998, among the Company and the stockholders party thereto, as the same
         may be amended or modified from time to time) to not consent to an
         initial public offering by the Company of its Common Stock; provided,
         however, that an Executive Management Stockholder Block shall not be
         deemed to have occurred if a decision or action by the Board of
         Directors or the holders of the Company's Series A Convertible
         Preferred Stock, $.001 par value, prevents the consummation of such an
         initial public offering.

                  8. Payments Upon Termination.

                  (a) Termination Without Cause. In the event that the
         Employee's employment is terminated by the Company Without Cause during
         the period between the Commencement Date and the date six months
         following the Commencement Date (the "Initial Period"), then the
         Company shall pay to the Employee, as severance pay or liquidated
         damages or both, monthly payments at the rate per annum of his Salary
         at the time of such termination for a period of:

                           (i) eighteen (18) months after such termination if
                  such termination occurs in the first month of the Initial
                  Period;

                           (ii) seventeen (17) months after such termination if
                  such termination occurs in the second month of the Initial
                  Period;

                           (iii) sixteen (16) months after such termination if
                  such termination occurs in the third month of the Initial
                  Period;

                           (iv) fifteen (15) months after such termination if
                  such termination occurs in the fourth month of the Initial
                  Period;

                           (v) fourteen (14) months after such termination if
                  such termination occurs in the fifth month of the Initial
                  Period;

                           (vi) thirteen (13) months after such termination if
                  such


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                  termination occurs in the sixth month of the Initial Period;
                  and

                           (vii) twelve (12) months after such termination if
                  such termination occurs after the end of the Initial Period.

                  (b) Termination by the Employee due to an Executive Management
         Stockholder Block. In the event that the Employee's employment is
         terminated by the Employee pursuant to clause (v) of Section 7(a) above
         during the ninety (90) day period following the date of such Executive
         Management Stockholder Block, then:

                           (i) the Company shall pay to the Employee, as
                  severance pay or liquidated damages or both, monthly payments
                  at the rate per annum of his Salary at the time of such
                  termination for a period of twenty-four (24) months after such
                  termination; and

                           (ii) the Company shall, upon the request therefor by
                  the Employee as described below, purchase up to 62,500 shares
                  of Common Stock acquired by the Employee pursuant to the
                  exercise of Initial Options upon the following terms and
                  conditions (the "Employee's Put"):

                                    (1) The Employee's Put may be exercised by
                           Employee at any time during the thirty (30) day
                           period following the Employee's termination by giving
                           written notice thereof ("Put Notice") to the Company
                           specifying the amount of shares (up to the maximum
                           referred to above) of Common Stock the Employee
                           wishes to sell to the Company (the "Put Securities").
                           The date of exercise of the Employee's Put shall be
                           the date of the Put Notice.

                                    (2) Within 30 days following receipt of the
                           Put Notice, the Company shall deliver to the Employee
                           a notice (the "Company Notice") stating the purchase
                           price per share of the Put Securities determined in
                           accordance with clause (4) hereof and a date and
                           place for closing of the purchase (the "Put
                           Closing"), which date shall be within ninety (90)
                           days after the date the Company receives the Put
                           Notice or, in the event an appraiser is hired
                           pursuant to clause (4) hereof, within ninety (90)
                           days after receipt of such appraiser's determination
                           of the purchase price of the Put Securities.

                                    (3) At the Put Closing, the Company shall
                           pay to the Employee the purchase price of the Put
                           Securities by check or wire transfer. At such Put
                           Closing, the Employee shall execute and deliver to
                           the Company such stock powers and such other
                           instruments of transfer as counsel for the Company
                           deems necessary to validly and effectively transfer
                           title to the Put Securities to the Company, free and
                           clear of any lien, claim or encumbrance.

                                    (4) The purchase price per share of the Put
                           Securities shall be the Fair Market Value (as defined
                           in Section 5(d) above) of the Common Stock on the
                           date of exercise of the Employee's Put. In the event
                           that such Fair Market Value was determined by the
                           Compensation Committee as described in Section
                           5(d)(iii) above, the Employee shall have the right to
                           disagree with such determination and elect, within
                           ten (10) days of receipt of the Company


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                           Notice, to have the Company select a recognized
                           business appraiser to calculate the purchase price of
                           the Put Securities which shall be the fair market
                           value thereof. The determination of the purchase
                           price by such appraiser will be binding on both
                           parties. All costs and expenses of the appraisal,
                           including, without limitation, all fees of the
                           appraiser, shall be borne by the Company.

                  (c) Payments Limited. Notwithstanding anything to the contrary
         expressed or implied herein, except as required by applicable law and
         except as set forth in Sections 8(a) and (b) above, neither the Company
         nor any of its affiliates shall be obligated to make any payments to
         the Employee or on his behalf of whatever kind or nature by reason of
         the Employee's cessation of employment (including, without limitation,
         by reason of termination of the Employee's employment by the Company's
         for Cause, Without Cause or otherwise), other than (i) such amounts, if
         any, of his Salary as shall have accrued and remained unpaid as of the
         date of said cessation and (ii) such other amounts, if any, which may
         be then otherwise payable to the Employee pursuant to the terms of the
         Company's benefits plans or pursuant to clause (v) of Section 5(a)
         above.

                  (d) Interest. No interest shall accrue on or be paid with
         respect to any portion of any payments under this Section 8.

                  9. Non-Assignability.

                  (a) Neither this Agreement nor any right or interest hereunder
         shall be assignable by the Employee or his beneficiaries or legal
         representatives without the Company's prior written consent; provided,
         however, that nothing in this Section 9(a) shall preclude the Employee
         from designating a beneficiary to receive any benefit payable hereunder
         upon his death or incapacity. This Agreement may not be assigned by the
         Company except with the Employee's prior written consent, provided,
         however, that the Company may assign this Agreement to an affiliate of
         the Company with the financial resources to fulfill the Company's
         obligations hereunder.

                  (b) Except as required by law, no right to receive payments
         under this Agreement shall be subject to anticipation, commutation,
         alienation, sale, assignment, encumbrance, charge, pledge, or
         hypothecation or to exclusion, attachment, levy or similar process or
         to assignment by operation of law, and any attempt, voluntary or
         involuntary, to effect any such action shall be null, void and of no
         effect.

                  10. Restrictive Covenants.

                  (a) Competition. During the Employment Term and, in the event
         the Employee's employment is terminated, during the period (the
         "Applicable Continuation Period") following such termination and
         continuing until (i) the last payment is made to the Employee pursuant
         to Section 8(a) or (b) hereof, as the case may be, or (ii) in the case
         of a termination of the Employee's employment pursuant to Section
         7(a)(iii) or (vi) hereof, the first anniversary of the date of such
         termination, the Employee will not directly or indirectly (as a
         director, officer, executive employee, manager, consultant, independent
         contractor, advisor or otherwise) engage in competition with, or own
         any interest in, perform any services for, participate in or be
         connected with any business or organization which engages in
         competition with any of the Companies within the meaning of Section
         10(d), provided, however, that the provisions of this Section 10(a)
         shall not be deemed to


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         prohibit the Employee's ownership of not more than two percent (2%) of
         the total shares of all classes of stock outstanding of any publicly
         held company, or ownership, whether through direct or indirect stock
         holdings or otherwise, of not more than one percent (1%) of any other
         business.

                  (b) Non-Solicitation. During the Employment Term and during
         the Applicable Continuation Period, the Employee will not directly or
         indirectly induce or attempt to induce any employee of any of the
         Companies to leave the employ of the Company or such subsidiary or
         affiliate, or in any way interfere with the relationship between any of
         the Companies and any employee thereof.

                  (c) Non-Interference. During the Employment Term and during
         the Applicable Continuation Period, the Employee will not directly or
         indirectly hire, engage, send any work to, place orders with, or in any
         manner be associated with any supplier, contractor, subcontractor or
         other business relation of any of the Companies if such action by him
         would have an adverse effect on the business, assets or financial
         condition of any of the Companies, or materially interfere with the
         relationship between any such person or entity and any of the
         Companies.

                  (d) Certain Definitions.

                           (i) For purposes of this Section 10, a person or
         entity (including, without limitation, the Employee) shall be deemed to
         be a competitor of one or more of the Companies, or a person or entity
         (including, without limitation, the Employee) shall be deemed to be
         engaging in competition with one or more of the Companies, if such
         person or entity conducts, or, to the knowledge of the Employee, plans
         to conduct, the Specified Business (as hereinafter defined) as a
         significant portion of its business in any of the markets served by the
         Companies or, in the case of a person or entity pursuing a business
         strategy of providing telecommunications infrastructure services
         anywhere in the continental United States.

                           (ii) For purposes of this Agreement, "Specified
         Business" means (A) providing outsourced telecommunications
         infrastructure services to local or long distance telecommunications
         providers or engaging in any business conducted by the Company at the
         time of termination of the Employee's employment with the Company or
         (B) conducting, operating, carrying out or engaging in the business of
         managing any entity described in clause (A).

                  (e) Certain Representations of the Employee. In connection
         with the foregoing provisions of this Section 10, the Employee
         represents that his experience, capabilities and circumstances are such
         that such provisions will not prevent him from earning a livelihood.
         The Employee further agrees that the limitations set forth in this
         Section 10 (including, without limitation, time and territorial
         limitations) are reasonable and properly required for the adequate
         protection of the current and future businesses of the Companies. It is
         understood and agreed that the covenants made by the Employee in this
         Section 10 (and in Section 6 hereof) shall survive the expiration or
         termination of this Agreement.

                  (f) Injunctive Relief. The Employee acknowledges and agrees
         that a remedy at law for any breach or threatened breach of the
         provisions of Section 10 hereof would be inadequate and, therefore,
         agrees that the Company and any of its subsidiaries or affiliates shall
         be entitled to seek injunctive relief in addition to any other
         available


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         rights and remedies in cases of any such breach or threatened breach;
         provided, however, that nothing contained herein shall be construed as
         prohibiting the Company or any of its affiliates from pursuing any
         other rights and remedies available for any such breach or threatened
         breach.

                  11. Representations and Warranties. The Employee represents
and warrants that he is not subject to or a party to any agreement, contract,
covenants, order or other restriction which in any way prohibits, restricts or
impairs the Employee's ability to enter into this Agreement and carry out his
duties and obligations hereunder. Each party hereto represents and warrants to
the other that (i) each has the full legal right and power and all authority and
approvals required to enter into, execute and deliver this Agreement and to
perform fully all of his or its obligations hereunder; and (ii) this Agreement
has been duly executed and delivered and constitutes a valid and binding
obligation of each party, enforceable in accordance with its terms.

                  12. Binding Effect. Without limiting or diminishing the effect
of Section 9 hereof, this Agreement shall inure to the benefit of and be binding
upon the parties hereto and their respective heirs, successors, legal
representatives and assigns.

                  13. Notices. All notices which are required or may be given
pursuant to the terms of this Agreement shall be in writing and shall be
sufficient in all respects if given in writing and (i) delivered personally,
(ii) mailed by certified or registered mail, return receipt requested and
postage prepaid, (iii) sent via a nationally recognized overnight courier or
(iv) sent via facsimile confirmed in writing to the recipient, if to the Company
at the Company's principal place of business, and if to the Employee, at his
home address most recently filed with the Company, or to such other address or
addresses as either party shall have designated in writing to the other party
hereto, provided, however, that any notice sent by certified or registered mail
shall be deemed delivered on the date of delivery as evidenced by the return
receipt.

                  14. Law Governing. This Agreement shall be governed by and
construed in accordance with the laws of the State of New York.

                  15. Severability. The Employee agrees that in the event that
any court of competent jurisdiction shall finally hold that any provision of
Section 6 or 10 hereof is void or constitutes an unreasonable restriction
against the Employee, the provisions of such Section 6 or 10 shall not be
rendered void but shall apply with respect to such extent as such court may
judicially determine constitutes a reasonable restriction under the
circumstances. If any part of this Agreement other than Section 6 or 10 is held
by a court of competent jurisdiction to be invalid, illegible or incapable of
being enforced in whole or in part by reason of any rule of law or public
policy, such part shall be deemed to be severed from the remainder of this
Agreement for the purpose only of the particular legal proceedings in question
and all other covenants and provisions of this Agreement shall in every other
respect continue in full force and effect and no covenant or provision shall be
deemed dependent upon any other covenant or provision.

                  16. Waiver. Failure to insist upon strict compliance with any
of the terms, covenants or conditions hereof shall not be deemed a waiver of
such term, covenant or condition, nor shall any waiver or relinquishment of any
right or power hereunder at any one or more times be deemed a waiver or
relinquishment of such right or power at any other time or times.

                  17. Entire Agreement; Modifications. This Agreement
constitutes the entire and final expression of the agreement of the parties with
respect to the subject matter hereof and supersedes all prior agreements, oral
and


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written, between the parties hereto with respect to the subject matter hereof.
This Agreement may be modified or amended only by an instrument in writing
signed by both parties hereto.

                  18. Counterparts. This Agreement may be executed in two or
more counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.





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                  IN WITNESS WHEREOF, the Company and the Employee have duly
executed and delivered this Agreement as of the day and year first above
written.

                                         LEXENT INC.



                                         By: /s/ Kevin O'Kane
                                            -----------------------------------
-------------                                Name:  Kevin O'Kane
                                             Title: C.O.O



                                                 /s/ Rif K. Haffar
                                         --------------------------------------
-------------                                     Rif K. Haffar






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<PAGE>   13
                                   SCHEDULE 1


                  The Separation and General Release Agreement between the
Employee and WinStar Wireless, Inc. ("WinStar") requires that the Employee for
the period through and including October 31, 2000 make himself reasonably
available upon WinStar's request to assist WinStar and its affiliates'
management in network or other operational matters and to respond to information
and other similar requests by WinStar. If such activities require travel to
out-of-state locations (the state being Virginia), such assistance shall be
arranged at times mutually convenient to both the Employee and WinStar. If the
Employee obtains full-time employment prior to October 31, 2000, the Employee
must continue to make himself available, upon WinStar's reasonable request, to
respond to information and other similar requests by WinStar through October 31,
2000.














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