Document:

<PAGE>

                                                                     Exhibit 4.2

                               WARRANT AGREEMENT

                        dated as of February [__], 2001

                                 by and between

                          FiberNet Telecom Group, Inc.

                                      and

                      The Warrant Holders Described Herein

<PAGE>

                               WARRANT AGREEMENT

                               TABLE OF CONTENTS/1/

<TABLE>
<CAPTION>
                                                                                         Page
                                                                                         ----
<S>            <C>                                                                       <C>

SECTION 1.     WARRANT CERTIFICATES.......................................................1

SECTION 2.     EXECUTION OF WARRANT CERTIFICATES..........................................1

SECTION 3.     RESTRICTIONS ON TRANSFERABILITY; REGISTRATION OF TRANSFERS AND
               EXCHANGES..................................................................1

SECTION 4.     TERMS OF WARRANTS; EXERCISE OF WARRANTS....................................3

SECTION 5.     PAYMENT OF TAXES...........................................................4

SECTION 6.     MUTILATED OR MISSING WARRANT CERTIFICATES..................................4

SECTION 7.     RESERVATION OF WARRANT SHARES..............................................4

SECTION 8.     OBTAINING STOCK EXCHANGE LISTINGS..........................................5

SECTION 9.     ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF WARRANT SHARES ISSUABLE.........5

SECTION 10.    FRACTIONAL INTERESTS......................................................11

SECTION 11.    COMPANY REDEMPTION........................................................11

SECTION 12.    NOTICES TO WARRANT HOLDERS................................................11

SECTION 13.    NOTICES TO COMPANY........................................................12

SECTION 14.    SUPPLEMENTS AND AMENDMENTS................................................13

SECTION 15.    SUCCESSORS................................................................13

SECTION 16.    TERMINATION...............................................................13

SECTION 17.    GOVERNING LAW.............................................................13

SECTION 18.    BENEFITS OF THIS AGREEMENT................................................13

SECTION 19.    HEADINGS; COUNTERPARTS....................................................14

</TABLE>
---------------------------
/1/  This Table of Contents does not constitute a part of this Agreement or have
     any bearing upon the interpretation of any of its terms or provisions.

<PAGE>

          WARRANT AGREEMENT, dated as of February __, 2001, between FiberNet
Telecom Group Inc., a Delaware corporation (the "Company"), and the holders of
Warrants (as defined below) from time to time.

          WHEREAS, the Company proposes to issue 1,288,000 Common Stock Purchase
Warrants (equal to 20% of the shares of Common Stock (as defined below)
purchased pursuant to the Common Stock and Warrant Purchase Agreement), as
hereinafter described (the "Warrants"), which entitle the holders thereof to
purchase the common stock, par value $.001 per share (the "Common Stock"), of
the Company (the Common Stock issuable on exercise of the Warrants being
referred to herein as the "Warrant Shares"), in connection with the Common Stock
and Warrant Purchase Agreement Agreement, dated as of the date hereof, between
the Company and the Purchasers named therein (the "Subscription Agreement");

          NOW, THEREFORE, in consideration of the premises and the mutual
agreements herein set forth, the parties hereto agree as follows:

          SECTION 1.  Warrant Certificates. The certificates evidencing the
Warrants (the "Warrant Certificates") to be delivered pursuant to this Agreement
shall be in registered form only and shall be substantially in the form set
forth in Exhibit A attached hereto.

          SECTION 2.  Execution of Warrant Certificates.

          Warrant Certificates shall be signed on behalf of the Company by its
Chairman of the Board or its President or a Vice President and by its Secretary
or an Assistant Secretary and shall be dated the date of signature by the
Company.

          The Company may deem and treat the registered holder(s) of the Warrant
Certificates as the absolute owner(s) thereof (notwithstanding any notation of
ownership or other writing thereon made by anyone), for all purposes, and the
Company shall not be affected by any notice to the contrary.

          SECTION 3.  Restrictions on Transferability; Registration of
Permitted Transfers and Exchanges. The Warrant holders agree that they shall not
transfer the Warrants to any one other than a member of their Group. For
purposes of this Section 3, a "Group" shall mean:

          (i) in the case of any Warrant holder who is an individual, (a) such
warrant holder, (b) the spouse, lineal descendants and adopted children of such
Warrant holder and (c) any trust for the benefit of any of the foregoing; and

          (ii) in the case of any Warrant Holder that is a corporation, limited
liability company or partnership, (a) such corporation, limited liability
company or partnership, (b) any corporation or other business organization to
which such corporation, limited liability company or partnership shall sell,
license or transfer all or substantially all of its assets or with which it
shall be merged, (c) with respect to any limited liability company or
partnership, any partner (general or limited) or member thereof and (d) any
affiliate of such corporation, limited liability company or partnership.

<PAGE>

          The Company shall from time to time, subject to the limitations of
Section 4, register the permitted transfer of any outstanding Warrant
Certificates upon the records to be maintained by it for that purpose, upon
surrender thereof duly endorsed or accompanied (if so required by it) by a
written instrument or instruments of transfer in form satisfactory to the
Company, duly executed by the registered holder or holders thereof or by the
duly appointed legal representative thereof or by a duly authorized attorney.
Upon any such registration of transfer, a new Warrant Certificate shall be
issued to the transferee(s) and the surrendered Warrant Certificate shall be
cancelled by the Company.

          The Warrant holders agree that prior to any proposed transfer of the
Warrants the Warrant holder will deliver to the Company:

          (1)  an agreement by such transferee to the impression of the
restrictive legend set forth below on the Warrant; and

          (2)  an agreement by such transferee to be bound by the provisions of
this Agreement.

          The Warrant holders agree that each Warrant will bear a legend in
substantially the following form:

          "THE SALE, TRANSFER OR ASSIGNMENT OF THE SECURITIES REPRESENTED BY
          THIS CERTIFICATE ARE SUBJECT TO THE TERMS AND CONDITIONS OF A CERTAIN
          WARRANT AGREEMENT DATED AS OF FEBRUARY 1, 2001, AS AMENDED FROM TIME
          TO TIME, AMONG THE COMPANY AND CERTAIN HOLDERS OF ITS OUTSTANDING
          WARRANTS.  COPIES OF SUCH AGREEMENT MAY BE OBTAINED AT NO COST BY
          WRITTEN REQUEST MADE BY THE HOLDER OF RECORD OF THIS CERTIFICATE TO
          THE SECRETARY OF THE COMPANY."

          Subject to the terms of this Agreement, Warrant Certificates may be
exchanged at the option of the holder(s) thereof, when surrendered to the
Company at its principal office, which is currently located at the address
listed in Section 13 hereof, for another Warrant Certificate or other Warrant
Certificates of like tenor and representing in the aggregate a like number of
Warrants.  Any holder desiring to exchange a Warrant Certificate shall deliver a
written request to the Company, and shall surrender, duly endorsed or
accompanied (if so required by the Company) by a written instrument or
instruments of transfer in form satisfactory to the Company, the Warrant
Certificate or Certificates to be so exchanged.  Warrant Certificates
surrendered for exchange shall be cancelled by the Company.

          SECTION 4.  Terms of Warrants; Exercise of Warrants.

          The initial exercise price per share at which Warrant Shares shall be
purchasable upon the exercise of Warrants (the "Exercise Price") shall be equal
to $6.56 per share.  Each Warrant shall be initially exercisable for one share
of Common Stock.

                                       2

<PAGE>

          Subject to the terms of this Agreement, each Warrant holder shall have
the right, from the date issuance of the Warrants until 5:00 p.m., New York City
time on February __, 2004 (the "Exercise Period"), to receive from the Company
the number of fully paid and nonassessable Warrant Shares which the holder may
at the time be entitled to receive on exercise of such Warrants and payment of
the Exercise Price then in effect for such Warrant Shares. Each Warrant not
exercised prior to 5:00 p.m., New York City time, on February __, 2004 shall
become void and all rights thereunder and all rights in respect thereof under
this agreement shall cease as of such time.

          A Warrant may be exercised upon surrender to the Company at its
principal office, which is currently located at the address listed in Section 13
hereof, of the certificate or certificates evidencing the Warrants to be
exercised with the form of election to purchase on the reverse thereof duly
filled in and signed, which signature shall be guaranteed by a participant in a
recognized Signature Guarantee Medallion Program and such other documentation as
the Company may reasonably request, and upon payment to the Company for the
account of the Company of the Exercise Price which is set forth in the form of
Warrant Certificate attached hereto as Exhibit A as adjusted as herein provided,
for the number of Warrant Shares in respect of which such Warrants are then
exercised.  Payment of the aggregate Exercise Price shall be made in cash or by
certified or official bank check payable to the order of the Company in New York
Clearing House Funds.

          Subject to the provisions of Section 5 hereof, upon such surrender of
Warrants and payment of the Exercise Price, the Company shall issue and cause to
be delivered within three business days to and in such name or names as the
Warrant holder may designate a certificate or certificates for the number of
full Warrant Shares issuable upon the exercise of such Warrants together with
cash as provided in Section 10; provided, however, that if any consolidation,
merger or lease or sale of assets is proposed to be effected by the Company as
described in subsection (i) of Section 9 hereof, or a tender offer or an
exchange offer for shares of Common Stock of the Company shall be made, upon
such surrender of Warrants and payment of the Exercise Price as aforesaid, the
Company shall, as soon as possible, but in any event not later than three
business days thereafter, issue and cause to be delivered the full number of
Warrant Shares issuable upon the exercise of such Warrants in the manner
described in this sentence together with cash as provided in Section 10.  Such
certificate or certificates shall be deemed to have been issued and any person
so designated to be named therein shall be deemed to have become a holder of
record of such Warrant Shares as of the date of the surrender of such Warrants
and payment of the Exercise Price.

          The Warrants shall be exercisable, at the election of the holders
thereof, either in full or from time to time in part and, in the event that a
certificate evidencing Warrants is exercised in respect of fewer than all of the
Warrant Shares issuable on such exercise at any time prior to the date of
expiration of the Warrants, a new certificate evidencing the remaining Warrant
or Warrants will be issued.  The Company may assume that any Warrant presented
for exercise is permitted to be so exercised under applicable law and shall have
no liability for acting in reliance on such assumption.

          All Warrant Certificates surrendered upon exercise of Warrants shall
be cancelled by the Company.

                                       3

<PAGE>

          The Company shall keep copies of this Agreement and any notices given
or received hereunder available for inspection by the holders with reasonable
prior written notice during normal business hours at its office.

          SECTION 5.  Payment of Taxes.  The Company will pay all documentary
stamp taxes attributable to the initial issuance of Warrant Shares upon the
exercise of Warrants; provided, however, that the Company shall not be required
to pay any tax or taxes which may be payable in respect of any transfer involved
in the issue of any Warrant Certificates or any certificates for Warrant Shares
in a name other than that of the registered holder of a Warrant Certificate
surrendered upon the exercise of a Warrant, and the Company shall not be
required to issue or deliver such Warrant Certificates unless or until the
person or persons requesting the issuance thereof shall have paid to the Company
the amount of such tax or shall have established to the satisfaction of the
Company that such tax has been paid.

          SECTION 6.  Mutilated or Missing Warrant Certificates.  In case any of
the Warrant Certificates shall be mutilated, lost, stolen or destroyed, the
Company may in its discretion issue, in exchange and substitution for and upon
cancellation of the mutilated Warrant Certificate, or in lieu of and
substitution for the Warrant Certificate lost, stolen or destroyed, a new
Warrant Certificate of like tenor and representing an equivalent number of
Warrants, but only upon receipt of evidence satisfactory to the Company of such
loss, theft or destruction of such Warrant Certificate and indemnity, if
requested, also satisfactory to the Company. Applicants for such substitute
Warrant Certificates shall also comply with such other reasonable regulations
and pay such other reasonable charges as the Company may prescribe.

          SECTION 7.  Reservation of Warrant Shares.  The Company will at all
times reserve and keep available, free from preemptive rights, out of the
aggregate of its authorized but unissued Common Stock or its authorized and
issued Common Stock held in its treasury, for the purpose of enabling it to
satisfy any obligation to issue Warrant Shares upon exercise of Warrants, the
maximum number of shares of Common Stock which may then be deliverable upon the
exercise of all outstanding Warrants.

          The Company or, if appointed, the transfer agent for the Common Stock
(the "Transfer Agent") and every subsequent transfer agent for any shares of the
Company's capital stock issuable upon the exercise of any of the rights of
purchase aforesaid will be irrevocably authorized and directed at all times to
reserve such number of authorized shares as shall be required for such purpose.
The Company will keep a copy of this Agreement on file with the Transfer Agent
and with every subsequent transfer agent for any shares of the Company's capital
stock issuable upon the exercise of the rights of purchase represented by the
Warrants.  The Company will supply such Transfer Agent with duly executed
certificates for such purposes and will provide or otherwise make available any
cash which may be payable as provided in Section 10.  The Company will furnish
such Transfer Agent a copy of all notices of adjustments and certificates
related thereto, transmitted to each holder pursuant to Section 12 hereof.

          Before taking any action which would cause an adjustment pursuant to
Section 9 hereof to reduce the Exercise Price below the then par value (if any)
of the Warrant Shares, the Company will take any corporate action which may, in
the opinion of its counsel (which may be

                                       4

<PAGE>

counsel employed by the Company), be necessary in order that the Company may
validly and legally issue fully paid and nonassessable Warrant Shares at the
Exercise Price as so adjusted.

          The Company covenants that all Warrant Shares which may be issued upon
exercise of Warrants will, upon payment of the Exercise Price therefor and
issue, be fully paid, nonassessable, free of preemptive rights and free from all
taxes, liens, charges and security interests with respect to the issue thereof.

          SECTION 8.  Obtaining Stock Exchange Listings.  The Company will from
time to time take all action which may be necessary so that the Warrant Shares,
immediately upon their issuance upon the exercise of Warrants, will be listed on
the principal securities exchanges and markets within the United States of
America, if any, on which other shares of Common Stock are then listed.

          SECTION 9.  Adjustment of Exercise Price and Number of Warrant Shares
Issuable.  The Exercise Price and the number of Warrant Shares issuable upon the
exercise of each Warrant are subject to adjustment from time to time upon the
occurrence of the events enumerated in this Section 9.  With respect to any
Warrant, no adjustment to the Exercise Price or to the number of Warrant Shares
issuable upon exercise shall be made for any event enumerated in this Section 9
if the date as to which the Company committed to undertake such event was prior
to such Warrant's issuance.  For purposes of this Section 9, "Common Stock"
means shares now or hereafter authorized of any class of common stock of the
Company and any other stock of the Company, however designated, that has the
right (subject to any prior rights of any class or series of preferred stock) to
participate in any distribution of the assets or earnings of the Company without
limit as to per share amount.

          (a)  Adjustment for Change in Capital Stock.

          If the Company:

               (1) pays a dividend or makes a distribution on its Common Stock
     in shares of its Common Stock;

               (2) subdivides its outstanding shares of Common Stock into a
     greater number of shares;

               (3) combines its outstanding shares of Common Stock into a
     smaller number of shares;

               (4) makes a distribution on its Common Stock in shares of its
     capital stock other than Common Stock; or

               (5) issues by reclassification of its Common Stock any shares of
     its capital stock,

     then the Warrant in effect immediately prior to such action shall be
     proportionately adjusted so that the holder of any Warrant thereafter
     exercised may receive the aggregate number and kind of shares of capital
     stock of the Company which he would have owned

                                       5

<PAGE>

     immediately following such action if such Warrant had been exercised
     immediately prior to such action.

          The adjustment shall become effective immediately after the record
date in the case of a dividend or distribution and immediately after the
effective date in the case of a subdivision, combination or reclassification.

          If after an adjustment a holder of a Warrant upon exercise of it may
receive shares of two or more classes of capital stock of the Company, the
Company shall determine the allocation of the adjusted Exercise Price between
the classes of capital stock.  After such allocation, the exercise privilege and
the Exercise Price of each class of capital stock shall thereafter be subject to
adjustment on terms comparable to those applicable to Common Stock in this
Section 9.

          Such adjustment shall be made successively whenever any event listed
above shall occur.

          (b)  Adjustments for Issuances.

                The Exercise Price shall be subject to adjustment from time to
     time as follows:

               (1)  If the Company shall, at any time or from time to time after
the date hereof, issue any shares of Common Stock (or be deemed to have issued
shares of Common Stock as provided herein), other than Excluded Stock, at a
price per share less than the current market price per share on such date of
issuance, then the applicable Exercise Price, as in effect immediately prior to
each such issuance, shall forthwith be lowered to a price equal to the quotient
obtained by dividing:

                    (A)  an amount equal to the sum of (x) the total number of
shares of Common Stock outstanding on a fully-diluted basis immediately prior to
such issuance, multiplied by the applicable Exercise Price in effect immediately
prior to such issuance, and (y) the consideration received by the Company upon
such issuance; by

                    (B)  the total number of shares of Common Stock outstanding
on a fully-diluted basis immediately after the issuance of such Common Stock.

               (2)  For the purposes of any adjustment of the applicable
Exercise Price pursuant to clause (1) above, the following provisions shall be
applicable:

                    (A)  In the case of the issuance of Common Stock for cash in
a public offering or private placement, the consideration shall be deemed to be
the amount of cash paid therefor after deducting therefrom any discounts,
commissions or placement fees payable by the Company to any underwriter or
placement agent in connection with the issuance and sale thereof.

                                       6

<PAGE>

                    (B)  In the case of the issuance of Common Stock for a
consideration in whole or in part other than cash, the consideration other than
cash shall be deemed to be the Fair Value Per Share, as defined below, thereof
notwithstanding any accounting treatment.

                    (C)  In this case of the issuance of options to purchase or
rights to subscribe for Common Stock, securities by their terms convertible into
or exchangeable for Common Stock, or options to purchase or rights to subscribe
for such convertible or exchangeable securities except for options to acquire
Excluded Stock:

                         (i)  the aggregate maximum number of shares of Common
Stock deliverable upon exercise of such options to purchase or rights to
subscribe for Common Stock shall be deemed to have been issued at the time such
options or rights were issued and for a consideration equal to the consideration
(determined in the manner provided in Sections 9(b)(2)(A) and 9(b)(2)(B) above),
if any, received by the Company upon the issuance of such options or rights plus
the minimum purchase price provided in such options or rights for the Common
Stock covered thereby;

                         (ii)  the aggregate maximum number of shares of Common
Stock deliverable upon conversion of or in exchange for any such convertible or
exchangeable securities or upon the exercise of options to purchase or rights to
subscribe for such convertible or exchangeable securities and subsequent
conversion or exchange thereof shall be deemed to have been issued at the time
such securities, options, or rights were issued and for a consideration equal to
the consideration received by the Company for any such securities and related
options or rights (excluding any cash received on account of accrued interest or
accrued dividends), plus the additional consideration, if any, to be received by
the Company upon the conversion or exchange of such securities or the exercise
of any related options or rights (the consideration in each case to be
determined in the manner provided in Sections 9(b)(2)(A) and 9(b)(2)(B) above);

                         (iii)  on any change in the number of shares or
exercise price of Common Stock deliverable upon exercise of any such options or
rights or conversions of or exchanges for such securities, other than a change
resulting from the antidilution provisions thereof, the Exercise Price shall
forthwith be readjusted to the Exercise Price as would have been obtained had
the adjustment made upon the issuance of such options, rights or securities not
converted prior to such change or options or rights related to such securities
not converted prior to such change been made upon the basis of such change; and

                         (iv)  on the expiration of any such options or rights,
the termination of any such rights to convert or exchange or the expiration of
any options or rights related to such convertible or exchangeable securities,
the Exercise Price shall forthwith be readjusted to the Exercise Price as would
have been obtained had the adjustment made upon the issuance of such options,
rights, securities or options or rights relaxed to such securities been made
upon the basis of the issuance of only the number of shares of Common Stock
actually issued upon the exercise of such options or rights, upon the conversion
or exchange of such securities, or upon the exercise of the options or rights
related to such securities and subsequent conversion or exchange thereof.

                                       7

<PAGE>

          The adjustment shall be made successively whenever any such
distribution is made and shall become effective immediately after the record
date for the determination of stockholders entitled to receive the distribution.

          This subsection (b) does not apply to regular quarterly cash dividends
or cash distributions paid out of consolidated current or retained earnings as
shown on the books of the Company prepared in accordance with generally accepted
accounting principles.

          For purposes of Section 9(b), "Excluded Stock" shall mean (A) shares
of Common Stock issuable upon exercise of stock options granted to officers,
employees, consultants, vendors or directors of the Corporation or its
subsidiaries, (B) shares of Common Stock issued upon conversion of shares of all
of the outstanding series of preferred stock as of the date hereof, (C) shares
of Common Stock issued upon exercise of any existing warrants, notes or other
instruments convertible or exercisable for Common Stock as of the date hereof,
(D) shares of Common Stock and warrants, and shares of Common Stock issuable
upon exercise of such warrants, as are contemplated by the Subscription
Agreement and Prospectus Supplement filed in connection with the issuance of the
Warrants and (E) Common Stock or other equity securities issued as part of a
strategic arrangement or alliance by the Corporation or its Subsidiaries to
building licensors, landlords, carriers, joint venture partners, vendors,
lessors or lenders, and securities or instruments issued in connection with
acquisitions, as each such transaction is approved by the Board of Directors of
the Company, including in the case of (A), (B), (C), (D) and (E), any additional
shares of Common Stock as may be issued by virtue of antidilution provisions, if
any, applicable to such options, warrants or shares, as the case may be.

          (c)  Current Market Price.

          In subsections (a) and (b) of this Section 9 the current market price
per share of Common Stock on any date is the average of the Quoted Prices of the
Common Stock for 10 consecutive trading days commencing 13 trading days before
the date in question.  The Company shall be solely responsible for tracking and
calculation of the Quoted Price and its average.  The "Quoted Price" of the
Common Stock is the last reported sales price of the Common Stock as reported by
the Nasdaq National Market System, or if the Common Stock is listed on a
securities exchange, the last reported sales price of the Common Stock on such
exchange which shall be for consolidated trading if applicable to such exchange,
or if neither so reported or listed, the last reported bid price of the Common
Stock.  In the absence of one or more such quotations, the Board of Directors of
the Company shall determine the current market price on the basis of such
quotations as it in good faith considers appropriate.

          (d)  When De Minimis Adjustment May Be Deferred.

          No adjustment in the Exercise Price need be made unless the adjustment
would require an increase or decrease of at least 1% in the Exercise Price.  Any
adjustments that are not made shall be carried forward and taken into account in
any subsequent adjustment.

          All calculations under this Section 9 shall be made to the nearest
cent or to the nearest 1/100th of a share, as the case may be.

                                       8

<PAGE>

          (e)  When No Adjustment Required.

          No adjustment need be made for a transaction referred to in
subsections (a) or (b) of this Section 9 if Warrant holders are to participate,
without requiring the Warrants to be exercised, in the transaction on a basis
and with notice that the Board of Directors of the Company determines to be fair
and appropriate in light of the basis and notice on which holders of Common
Stock participate in the transaction.

          No adjustment need be made for a change in the par value or no par
value of the Common Stock.

          To the extent the Warrants become convertible into cash, no adjustment
need be made thereafter as to the amount of cash into which such Warrants are
exercisable.  Interest will not accrue on the cash.

          (f)  Notice of Adjustment.

          Whenever the Exercise Price is adjusted, the Company shall provide the
notices required by Section 12 hereof.

          (g)  Voluntary Reduction.

          The Company from time to time may reduce the Exercise Price by any
amount for any period of time (including, without limitation, permanently) if
such period is at least 20 days; provided, however, that in no event may the
Exercise Price be less than the par value of a share of Common Stock.

          Whenever the Exercise Price is reduced, the Company shall mail to
Warrant holders a notice of the reduction.  The Company shall mail the notice at
least 15 days before the date the reduced Exercise Price takes effect.  The
notice shall state the reduced Exercise Price and the period it will be in
effect.

          A reduction of the Exercise Price does not change or adjust the
Exercise Price otherwise in effect for purposes of subsections (a), (b), and (c)
of this Section 9.

          (h)  Reorganization of Company.

          If the Company consolidates or merges with or into, or transfers,
licenses or leases all or substantially all its assets to, any person, upon
consummation of such transaction the Warrants shall automatically become
exercisable for the kind and amount of securities, cash or other assets which
the holder of a Warrant would have owned immediately after the consolidation,
merger, transfer or lease if the holder had exercised the Warrant immediately
before the effective date of the transaction.  Concurrently with the
consummation of such transaction, the corporation formed by or surviving any
such consolidation or merger if other than the Company, or the person to which
such sale or conveyance shall have been made, shall enter into a supplemental
Warrant Agreement so providing and further providing for adjustments which shall
be as nearly equivalent as may be practical to the adjustments provided for in
this

                                       9

<PAGE>

Section. The successor Company shall mail to Warrant holders a notice describing
the supplemental Warrant Agreement.

          If the issuer of securities deliverable upon exercise of Warrants
under the supplemental Warrant Agreement is an affiliate of the formed,
surviving, transferee or lessee corporation, that issuer shall join in the
supplemental Warrant Agreement.

          If this subsection (h) applies, subsections (a), (b), and (c) of this
Section 9 do not apply.

          (1)  When Issuance or Payment May Be Deferred.

          In any case in which this Section 9 shall require that an adjustment
in the Exercise Price be made effective as of a record date for a specified
event, the Company may elect to defer until the occurrence of such event (i)
issuing to the holder of any Warrant exercised after such record date the
Warrant Shares and other capital stock of the Company, if any, issuable upon
such exercise over and above the Warrant Shares and other capital stock of the
Company, if any, issuable upon such exercise on the basis of the Exercise Price
and (ii) paying to such holder any amount in cash in lieu of a fractional share
pursuant to Section 10; provided, however, that the Company shall deliver to
such holder a due bill or other appropriate instrument evidencing such holder's
right to receive such additional Warrant Shares, other capital stock and cash
upon the occurrence of the event requiring such adjustment.

          (j)  Adjustment in Number of Shares.

          Upon each event that provides for an adjustment of the Exercise Price
pursuant to Section 9(a), each Warrant outstanding prior to the making of the
adjustment shall thereafter evidence the right to receive upon payment of the
adjusted Exercise Price that number of shares of Common Stock obtained from the
following formula:

        N'  =  N  x  E
                     -
                     E'

     where:

     N' =  the adjusted number of Warrant Shares issuable upon exercise of a
           Warrant by payment of the adjusted Exercise Price.

     N  =  the number of Warrant Shares previously issuable upon exercise of a
           Warrant by payment of the Exercise Price prior to adjustment.

     E' =  the adjusted Exercise Price.

     E  =  the Exercise Price prior to adjustment.

                                      10

<PAGE>

          (k)  Form of Warrants.

          Irrespective of any adjustments in the Exercise Price or the number or
kind of shares purchasable upon the exercise of the Warrants, Warrants
theretofore or thereafter issued may continue to express the same price and
number and kind of shares as are stated in the Warrants initially issuable
pursuant to this Agreement.

          SECTION 10.  Fractional Interests.

          (a)  The Company shall not be required to issue fractional Warrant
Shares on the exercise of Warrants.  If more than one Warrant shall be presented
for exercise in full at the same time by the same holder, the number of full
Warrant Shares which shall be issuable upon the exercise thereof shall be
computed on the basis of the aggregate number of Warrant Shares purchasable on
exercise of the Warrants so presented.  If any fraction of a Warrant Share
would, except for the provisions of this Section 10, be issuable on the exercise
of any Warrants (or specified portion thereof), the Company shall pay an amount
in cash equal to the fair market value on the day immediately preceding the date
the Warrant is presented for exercise, multiplied by such fraction.

          (b)  Warrants may be issued in fractional interests.  Holders of
fractional interests in Warrants will be entitled to purchase a number of
Warrant Shares equal to the product obtained by multiplying the number of
Warrant Shares issuable with respect to a full Warrant multiplied by the
fractional interest owned by such holder in the Warrant.

          SECTION 11.  Company Redemption.

          If the Quoted Price for the Common Stock is greater than 175% of the
Exercise Price for 20 consecutive trading days and the Company's Registration
Statement on Form S-3, initially filed on August 15, 2000, as amended on
September 8, 2000, November 9, 2000, January 10, 2001 and January 18, 2001
(Registration No. 333-43788), is in effect, the Company may redeem the Warrants
for $.10 per Warrant upon ten trading days notice.

          SECTION 12.  Notices to Warrant holders.

          Upon any adjustment of the Exercise Price pursuant to Section 9, the
Company shall promptly thereafter, or within five days, cause to be given to
each of the registered holders of the Warrant Certificates at his address
appearing on the Warrant register written notice of such adjustments by first-
class mail, postage prepaid.  Where appropriate, such notice may be given in
advance and included as a part of the notice required to be mailed under the
other provisions of this Section 12.

          In case:

          (a)  the Company shall authorize the issuance to all holders of shares
of Common Stock of rights, options or warrants to subscribe for or purchase
shares of Common Stock or of any other subscription rights or warrants; or

          (b)  the Company shall authorize the distribution to all holders of
shares of Common Stock of evidences of its indebtedness or assets (other than
cash dividends or cash distributions payable out of consolidated earnings or
earned surplus or dividends payable in shares of Common Stock or distributions
referred to in subsection (a) of Section 9 hereof); or

                                      11

<PAGE>

          (c)  of any consolidation or merger to which the Company is a party
and for which approval of any shareholders of the Company is required, or of the
conveyance or transfer of the properties and assets of the Company substantially
as an entirety, or of any reclassification or change of Common Stock issuable
upon exercise of the Warrants (other than a change in par value, or from par
value to no par value, or from no par value to par value, or as a result of a
subdivision or combination), or a tender offer or exchange offer for shares of
Common Stock; or

          (d)  of the voluntary or involuntary dissolution, liquidation or
winding up of the Company; or

          (e)  the Company proposes to take any action (other than actions of
the character described in Section 9(a)) which would require an adjustment of
the Exercise Price pursuant to Section 9; then the Company shall cause to be
given to each of the registered holders of the Warrant Certificates at his
address appearing on the Warrant register, at least 15 calendar days (or 10
calendar days in any case specified in clauses (a) or (b) above) prior to the
applicable record date hereinafter specified, or promptly in the case of events
for which there is no record date, by first-class mail, postage prepaid, a
written notice stating (i) the date as of which the holders of record of shares
of Common Stock to be entitled to receive any such rights, options, warrants or
distribution are to be determined, or (ii) the initial expiration date set forth
in any tender offer or exchange offer for shares of Common Stock, or (iii) the
date on which any such consolidation, merger, conveyance, transfer, dissolution,
liquidation or winding up is expected to become effective or consummated, and
the date as of which it is expected that holders of record of shares of Common
Stock shall be entitled to exchange such shares for securities or other
property, if any, deliverable upon such reclassification, consolidation, merger,
conveyance, transfer, dissolution, liquidation or winding up.  The failure to
give the notice required by this Section 12 or any defect therein shall not
affect the legality or validity of any distribution, right, option, warrant,
consolidation, merger, conveyance, transfer, dissolution, liquidation or winding
up, or the vote upon any action.

          Nothing contained in this Agreement or in any of the Warrant
Certificates shall be construed as conferring upon the holders thereof the right
to vote or to consent or to receive notice as shareholders in respect of the
meetings of shareholders or the election of Directors of the Company or any
other matter, or any rights whatsoever as shareholders of the Company.

          SECTION 13.  Notices to Company.

          Any notice or demand authorized by this Agreement to be given or made
by the registered holder of any Warrant Certificate to or on the Company shall
be sufficiently given or made when and if deposited in the mail, first class or
registered, postage prepaid, addressed (until another address is provided in
writing by the Company), as follows:

                            FiberNet Telecom Group, Inc.
                            570 Lexington Avenue
                            New York, New York 10022
                            Attn: President

                                      12

<PAGE>

                              with a copy to:

                            Mintz Levin Cohn Ferris Glovsky and Popeo, P.C.
                            Chrysler Center
                            666 Third Avenue
                            New York, New York 10017
                            Attn:  Gordon Caplan, Esq.

          SECTION 14.  Supplements and Amendments.

          The Company may from time to time supplement or amend this Agreement
(a) without the approval of any holders of Warrant Certificates in order to cure
any ambiguity or to correct or supplement any provision contained herein which
may be defective or inconsistent with any other provision herein, or to make any
other provisions in regard to matters or questions arising hereunder which the
Company may deem necessary or desirable and which shall not in any way adversely
affect the interests of the holders of Warrant Certificates, or (b) with the
approval of the holders of a majority of the Warrants outstanding.

          SECTION 15.  Successors.

          All the covenants and provisions of this Agreement by or for the
benefit of the Company shall be binding and inure to the benefit of its
respective successors and assigns hereunder.

          SECTION 16.  Termination.

           This Agreement will terminate on any earlier date if all Warrants
have been exercised or expired without exercise.

          SECTION 17.  Governing Law.

          This Agreement and each Warrant Certificate issued hereunder shall be
deemed to be a contract made under the laws of the State of New York and for all
purposes shall be construed in accordance with the internal laws of said State.

          SECTION 18.  Benefits of This Agreement.

          Nothing in this Agreement shall be construed to give to any person or
corporation other than the Company and the registered holders of the Warrant
Certificates any legal or equitable right, remedy or claim under this Agreement;
but this Agreement shall be for the sole and exclusive benefit of the Company
and the registered holders of the Warrant Certificates.

          SECTION 19.  Headings; Counterparts.

          The headings and captions contained herein are for convenience of
reference only and shall not control or affect the meaning or construction of
any provision hereof.  This Agreement may be executed in any number of
counterparts and each of such counterparts shall for all purposes be deemed to
be an original, and all such counterparts shall together constitute but one and
the same instrument.

                            [Signature Page Follows]

                                      13

<PAGE>

          IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed, as of the day and year first above written.

                              FIBERNET TELECOM GROUP, INC.

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

                              [____________________________]

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

                              [____________________________]

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

                                      14

<PAGE>

                                                                       EXHIBIT A

                         [Form of Warrant Certificate]

[Face]

No. _____                                                        _______Warrants

                              Warrant Certificate

          This Warrant Certificate certifies that ________________________, or
registered assigns, is the registered holder of ________Warrants expiring
February __, 2004 (the "Warrants") to purchase Common Stock, $.001 par value
(the "Common Stock"), of FiberNet Telecom Group, Inc., a Delaware corporation
(the "Company").  Each Warrant entitles the holder upon exercise to receive from
the Company on or before 5:00 p.m. New York City Time on February__, 2004 that
number of fully paid and nonassessable shares of Common Stock (each, a "Warrant
Share") as set forth below at the exercise price (the "Exercise Price") as
determined pursuant to the Warrant Agreement referenced below payable in lawful
money of the United States of America upon surrender of this Warrant Certificate
and payment of the Exercise Price at the office of the Company, but only subject
to the conditions set forth herein and in the Warrant Agreement referred to on
the reverse hereof.  The Exercise Price and number of Warrant Shares issuable
upon exercise of the Warrants are subject to adjustment upon the occurrence of
certain events set forth in the Warrant Agreement.

          Each Warrant is initially exercisable for one share of Common Stock.
The initial Exercise Price for any Warrant shall be $6.56.  No warrant may be
exercised after 5:00 p.m. New York City Time on February__, 2004 and to the
extent not exercised by such time such warrants shall become void.

          Reference is hereby made to the further provisions of this Warrant
Certificate set forth on the reverse hereof and such further provisions shall
for all purposes have the same effect as though fully set forth at this place.

          This Warrant Certificate shall be governed and construed in accordance
with the internal laws of the State of New York.

IN WITNESS WHEREOF, the Company has caused this Warrant Certificate to be signed
by its President and by its Secretary.

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

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

<PAGE>

                         [Form of Warrant Certificate]

[Reverse]

          The Warrants evidenced by this Warrant Certificate are part of a duly
authorized issue of Warrants expiring February  __, 2004 entitling the holder on
exercise to receive shares of Common Stock, par value $.001 per share, of the
Company (the "Common Stock") and are issued or to be issued pursuant to a
Warrant Agreement, dated as of February __, 2001 (the "Warrant Agreement"), duly
executed and delivered by the Company, which Warrant Agreement is hereby
incorporated by reference in and made a part of this instrument and is hereby
referred to for a description of the rights, limitation of rights, obligations,
duties and immunities thereunder of the Company and the holders (the words
"holders" or "holder" meaning the registered holders or registered holder) of
the Warrants.  A copy of the Warrant Agreement may be obtained by the holder
hereof upon written request to the Company.

          Warrants may be exercised at any time on or before 5:00 p.m. New York
City time on February __, 2004.  The holder of Warrants evidenced by this
Warrant Certificate may exercise them by surrendering this Warrant Certificate,
with the form of election to purchase set forth hereon properly completed and
executed, together with payment of the Exercise Price as specified in the
Warrant Agreement at the office of the Company.  In the event that upon any
exercise of Warrants evidenced hereby the number of Warrants exercised shall be
less than the total number of Warrants evidenced hereby, there shall be issued
to the holder hereof or his assignee a new Warrant Certificate evidencing the
number of Warrants not exercised.  No adjustment shall be made for any dividends
on any Common Stock issuable upon exercise of this Warrant.

          The Warrant Agreement provides that upon the occurrence of certain
events the Exercise Price set forth on the face hereof may, subject to certain
conditions, be adjusted.  If the Exercise Price is adjusted, the Warrant
Agreement provides that the number of shares of Common Stock issuable upon the
exercise of each Warrant shall be adjusted.  No fractions of a share of Common
Stock will be issued upon the exercise of any Warrant, but the Company will pay
the cash value thereof determined as provided in the Warrant Agreement.

        Warrant Certificates, when surrendered at the office of the Company by
the registered holder thereof in person or by legal representative or attorney
duly authorized in writing, may be exchanged, in the manner and subject to the
limitations provided in the Warrant Agreement, but without payment of any
service charge, for another Warrant Certificate or Warrant Certificates of like
tenor evidencing in the aggregate a like number of Warrants.

          Upon due presentation for registration of transfer of this Warrant
Certificate at the office of the Company a new Warrant Certificate or Warrant
Certificates of like tenor and evidencing in the aggregate a like number of
Warrants shall be issued to the transferee(s) in exchange for this Warrant
Certificate, subject to the limitations provided in the Warrant Agreement,
without charge except for any tax or other governmental charge imposed in
connection therewith.

          The Company may deem and treat the registered holder(s) thereof as the
absolute owner(s) of this Warrant Certificate (notwithstanding any notation of
ownership or other writing hereon made by anyone), for the purpose of any
exercise hereof, of any distribution to the holder(s) hereof, and for all other
purposes, and the Company shall not be affected by any notice to the contrary.
Neither the Warrants nor this Warrant Certificate entitles any holder hereof to
any rights of a stockholder of the Company.

                                      ii

<PAGE>

                              Election to Purchase

                   (to be executed upon exercise of warrant)

          The undersigned hereby irrevocably elects to exercise the right,
represented by this Warrant Certificate, to receive __________ shares of Common
Stock and herewith tenders payment for such shares to the order of
_________________ in the amount of $______ in accordance with the terms hereof.
The undersigned requests that a certificate for such shares be registered in the
name of ________________, whose address is __________________________ and that
such shares be delivered to ________________ whose address is ___________
______________________.  If said number of shares is less than all of the shares
of Common Stock purchasable hereunder, the undersigned requests that a new
Warrant Certificate representing the remaining balance of such shares be
registered in the name of ______________, whose address is
_________________________, and that such Warrant Certificate be delivered to
_________________, whose address is __________________.

                                         Signature:

Date:

                                          Signature Guaranteed:<PAGE>

                                                                    EXHIBIT 10.1

                                                                  EXECUTION COPY

                  COMMON STOCK AND WARRANT PURCHASE AGREEMENT

                         Dated as of February 1, 2001

                                by and between

                         FIBERNET TELECOM GROUP, INC.

                                      and

                          THE PURCHASERS NAMED HEREIN

<PAGE>

                        COMMON STOCK PURCHASE AGREEMENT

     This COMMON STOCK AND WARRANT PURCHASE AGREEMENT (this "Agreement") is
dated as of February 1, 2001 by and among FiberNet Telecom Group, Inc., a
Delaware corporation (the "Company"), and the purchasers identified on Exhibit A
attached hereto (individually, a "Purchaser" and collectively, the
"Purchasers").

     The parties hereto agree as follows:

                                   ARTICLE I

                                  Definitions

          Section 1.1    Definitions.

          (a)  "Business Day" shall mean any day other than a Saturday, Sunday
or day on which banks are permitted to close in the State of Delaware.

          (b)  "Commission" shall have the meaning assigned to such term in
Section 2.3 hereof.

          (c)  "Commission Documents" shall have the meaning assigned to such
term in Section 3.1(d) hereof.

          (d)  "Commission Filings" means the Company's Form 10-KSB for the
fiscal year ended December 31, 1999, its Form 10-QSB for the fiscal quarter
ended March 31, 2000, its Form 10-QSB for the fiscal quarter ended June 30,
2000, its Form 10QSB for the fiscal quarter ended September 30, 2000, its Form
8-K filed on April 14, 2000, its Form 8-K filed on June 8, 2000, its Form 8-K
filed on July 11, 2000, its Form 8-K dated August 4, 2000, its Form 8-K filed on
August 15, 2000, its Registration Statement on Form S-3 (No. 333-43788), and all
other filings made by the Company after the date hereof pursuant to the
Securities Exchange Act of 1934, as amended (the "Exchange Act").

          (e)  "Material Adverse Effect" shall mean any effect on the business,
results of operations, assets or financial condition of the Company that is
material and adverse to the Company and its subsidiaries, taken as a whole
and/or any condition, circumstance, or situation that would prohibit the Company
from entering into and performing any of its obligations under this Agreement in
any material respect.

          (f)  "Prospectus" as used in this Agreement means the prospectus in
the form included in the Registration Statement, as supplemented from time to
time pursuant to Rule 424(b) of the Securities Act of 1933, as amended (the
"Securities Act").
<PAGE>

          (g)  "Registration Statement" shall mean the registration statement on
Form S-3, Commission File Number 333-43788, under the Securities Act, filed with
the Securities and Exchange Commission, and subsequently declared effective by
the Securities and Exchange Commission, for the registration of the Shares, as
such Registration Statement may be amended from time to time.

          (h)  "Shares" shall mean the Warrants and shares of Common Stock of
the Company that are sold under the terms of this Agreement.

                                  ARTICLE II

                 Purchase and Sale of Common Stock and Warrant

          Section 2.1    Authorization. The Company has duly authorized the sale
and issuance, pursuant to the terms of this Agreement, of (a) 6,440,000 shares
of its common stock, $0.001 par value per share (the "Common Stock") and (b)
warrants to purchase 1,288,000 shares of Common Stock (the "Warrants").

          Section 2.2    Purchase and Sale of Stock. Upon execution of this
Agreement, the Purchasers shall deliver the Purchase Price (as defined herein)
to the escrow agent pursuant to the Escrow Agreement attached hereto as Exhibit
B. Subject to the terms and conditions of this Agreement, at the Closing (as
defined in Section 2.4) the Company shall issue and sell to the Purchasers and
the Purchasers shall purchase from the Company in the aggregate 6,440,000 shares
of Common Stock at a purchase price of $4.375 per share, for an aggregate
purchase price of Twenty Eight Million One Hundred and Seventy Five Thousand
($28,175,000) (the "Purchase Price"), which amount shall include the Warrants.

          Section 2.3    Registration Statement and Prospectus. The Company has
prepared and filed with the Securities and Exchange Commission (the
"Commission") in accordance with the provisions of the Securities Act, the
Registration Statement, including a prospectus subject to completion relating to
the Shares.

          Section 2.4    Purchase Price, Closing and Settlement. In
consideration of and in express reliance upon the representations, warranties,
covenants, terms and conditions of this Agreement, the Company agrees to issue
and sell to the Purchasers and the Purchasers, agree to purchase from the
Company, the Warrants and that number of the shares of the Company's Common
Stock as set forth on Exhibit A to this Agreement. The purchase and sale of the
Shares, and release of the Purchase Price from escrow, (the "Closing") shall
take place at the offices of the Company on (i) a date not later than February
9, 2001 or (ii) such other place or date as the Purchasers and the Company may
agree upon (the "Closing Date"). Each party shall deliver all documents,
instruments and writings required to be delivered by such party pursuant to this
Agreement at or prior to the Closing. On the Closing Date, the Company shall
deliver the Shares purchased by the Purchasers to the Purchasers or their
designee, as indicated in writing by the Purchasers, against payment therefor to
the Company's designated account by wire transfer of immediately available
funds. In the event the Escrow Agreement terminates and is no longer

                                       2
<PAGE>

of any force or effect prior to Closing, then this Agreement shall terminate and
the parties hereto shall have no further obligations under this Agreement.

[THE REMAINDER OF THIS PAGE IS INTENTIONALLY LEFT BLANK]

                                       3
<PAGE>

                                  ARTICLE III

                        Representations and Warranties

          Section 3.1    Representations and Warranties of the Company. The
Company hereby makes the following representations and warranties to the
Purchasers:

          (a)  Organization, Good Standing and Power. The Company is a
corporation duly incorporated, validly existing and in good standing under the
laws of Delaware and has the requisite corporate power to own, lease and operate
its properties and assets and to conduct its business as it is now being
conducted. As of the date hereof, the Company does not have any subsidiaries (as
defined in Section 3.1(g)) except as set forth in the Registration Statement and
in the Company's most recent Form 10-KSB, including the accompanying financial
statements (the "Form 10-K"), or in the Company's most recent Form 10-QSB (the
"Form 10-Q"), or on Schedule 3.1(e) attached hereto. The Company and each such
subsidiary is duly qualified to do business as a foreign corporation and is in
good standing in every jurisdiction in which the nature of the business
conducted or property owned by it makes such qualification necessary except for
any jurisdiction in which the failure to be so qualified will not have a
Material Adverse Effect.

          (b)  Authorization; Enforcement. The Company has the requisite
corporate power and authority to enter into and perform this Agreement and to
issue and sell the Shares in accordance with the terms hereof. The execution,
delivery and performance of this Agreement by the Company and the consummation
by it of the transactions contemplated hereby have been duly and validly
authorized by all necessary corporate action, and no further consent or
authorization of the Company or its Board of Directors or stockholders is
required. This Agreement has been duly executed and delivered by the Company.
This Agreement constitutes, or when executed and delivered shall constitute, a
valid and binding obligation of the Company enforceable against the Company in
accordance with its terms, except as such enforceability may be limited by
applicable bankruptcy, insolvency, reorganization, moratorium, liquidation,
conservatorship, receivership or similar laws relating to, or affecting
generally the enforcement of, creditor's rights and remedies or by other
equitable principles of general application.

          (c)  Issuance of Shares. The Shares have been duly authorized by all
necessary corporate action and, when paid for or issued in accordance with the
terms hereof, the Common Stock shall be validly issued and outstanding, fully
paid and non-assessable, and upon payment of the exercise price in accordance
with the terms of the Warrant Agreement, the form of which is attached hereto as
Exhibit C, the shares of Common Stock issuable upon exercise of the Warrants
shall be validly issued and outstanding, fully paid and non-assessable.

          (d)  Commission Documents, Financial Statements. The Common Stock of
the Company is registered pursuant to Section 12(b) or 12(g) of the Exchange
Act, and, except as disclosed in the Registration Statement, or the Commission
Documents or the Commission Filings, as of the date hereof, the Company has
timely filed all reports, schedules, forms, statements and other documents
required to be filed by it with the Commission pursuant to the

                                       4
<PAGE>

reporting requirements of the Exchange Act, including material filed pursuant to
Section 13(a) or 15(d) of the Exchange Act (all of the foregoing including
filings incorporated by reference therein being referred to herein as the
"Commission Documents"). The Company has made available to the Purchasers true
and complete copies of the Commission Documents filed with the Commission since
December 31, 1999 and prior to the Closing Date. The Company has not provided to
the Purchasers any information which, according to applicable law, rule or
regulation, should have been disclosed publicly by the Company but which has not
been so disclosed, other than with respect to the transactions contemplated by
this Agreement. The Form 10-KSB for the year ended December 31, 1999 complied in
all material respects with the requirements of the Exchange Act and the rules
and regulations of the Commission promulgated thereunder and other federal,
state and local laws, rules and regulations applicable to such document, and, as
of its date, such Form 10-KSB did not contain any untrue statement of a material
fact or omit to state a material fact required to be stated therein or necessary
in order to make the statements therein, in light of the circumstances under
which they were made, not misleading. The financial statements of the Company
included in the Commission Documents complied as to form in all material
respects with applicable accounting requirements and the published rules and
regulations of the Commission or other applicable rules and regulations with
respect thereto. Such financial statements have been prepared in accordance with
generally accepted accounting principles ("GAAP") applied on a consistent basis
during the periods involved (except (i) as may be otherwise indicated in such
financial statements or the notes thereto or (ii) in the case of unaudited
interim statements, to the extent they may not include footnotes or may be
condensed or summary statements), and fairly present in all material respects
the financial position of the Company and its subsidiaries as of the dates
thereof and the results of operations and cash flows for the periods then ended
(subject, in the case of unaudited statements, to normal year-end audit
adjustments).

          (e)  Subsidiaries. The Commission Documents or Schedule 3.1(e) set
forth each subsidiary of the Company as of the date hereof, showing the
jurisdiction of its incorporation or organization. For the purposes of this
Agreement, "subsidiary" shall mean any corporation or other entity of which at
least a majority of the securities or other ownership interest having ordinary
voting power (absolutely or contingently) for the election of directors or other
persons performing similar functions are at the time owned directly or
indirectly by the Company and/or any of its other subsidiaries. Except as set
forth in the Commission Documents or the Commission Filings, none of such
subsidiaries is a "significant subsidiary" as defined in Regulation S-X.

          (f)  Certain Fees. Other than the fees of H.C. Wainwright & Co., Inc.
and Kaufman Bros., L.P., for which the Company shall be solely responsible, no
brokers, finders or financial advisory fees or commissions will be payable by
the Company or any subsidiary with respect to the transactions contemplated by
this Agreement.

          (g)  Securities Act of 1933. The Company has complied in all material
respects with all applicable federal and state securities laws in connection
with the offer, issuance and sale of the Shares hereunder.

               (i)       Each Prospectus included as part of the Registration
Statement as originally filed or as part of any amendment or supplement thereto,
or filed pursuant to Rule 424

                                       5
<PAGE>

under the Securities Act, complied when so filed in all material respects with
the provisions of the Securities Act. The Commission has not issued any order
preventing or suspending the use of any Prospectus.

               (ii)      The Company meets the requirements for the use of Form
S-3 under the Securities Act. The Registration Statement in the form in which it
became effective and also in such form as it may be when any post-effective
amendment thereto became effective and the Prospectus and any supplement or
amendment thereto when filed with the Commission under Rule 424(b) under the
Securities Act, complied in all material respects with the provisions of the
Securities Act and did not at any such times contain an untrue statement of a
material fact or omit to state a material fact required to be stated therein or
necessary to make the statements therein (in the case of the Prospectus, in the
light of the circumstances under which they were made) not misleading, except
that this representation and warranty does not apply to statements in or
omissions from the Registration Statement or the Prospectus made in reliance
upon and in conformity with information relating to the Purchasers furnished to
the Company in writing by or on behalf of the Purchasers expressly for use
therein.

               (iii)     The Company has not distributed and, prior to the
completion of the sale of the Shares to the Purchasers, will not distribute any
offering material in connection with the offer and sale of the Shares other than
the Registration Statement, the Prospectus or other materials, if any, permitted
by the Securities Act.

          (h)  Use of Proceeds. The proceeds from the sale of the Shares will be
used by the Company and its subsidiaries for the purposes set forth in the
Prospectus under "Use of Proceeds."

          (i)  Registration Statement. The sale and issuance by the Company of
the Shares have been validly registered pursuant to the Registration Statement
and such shares of Common Stock will be issued without a restrictive legend.

          Section 3.2    Representations, Warranties and Covenants of the
Purchasers. Each Purchaser, individually on behalf of itself, hereby makes the
following representations, warranties and covenants to the Company:

          (a)  Organization and Standing of the Purchaser. The Purchaser is an
entity duly organized, validly existing and in good standing under the laws of
the jurisdiction identified on Exhibit A .

          (b)  Authorization and Power. The Purchaser has the requisite power
and authority to enter into and perform this Agreement and to purchase the
Shares in accordance with the terms hereof. The execution, delivery and
performance of this Agreement by the Purchaser and the consummation by it of the
transactions contemplated hereby have been duly authorized by all necessary
action, and no further consent or authorization of the Purchaser, its Board of
Directors or stockholders is required. This Agreement constitutes, or when
executed and delivered shall constitute, a valid and binding obligation of the
Purchaser enforceable against the Purchaser in accordance with its terms, except
as such enforceability may be limited by applicable bankruptcy, insolvency,
reorganization, moratorium, liquidation, conservatorship,

                                       6
<PAGE>

receivership, or similar laws relating to, or affecting generally the
enforcement of creditor's rights and remedies or by other equitable principles
of general application.

          (c)  No Conflicts. The execution, delivery and performance of this
Agreement and the consummation by the Purchaser of the transactions contemplated
hereby and thereby or relating hereto do not and will not (i) result in a
violation of such Purchaser's charter documents or bylaws or (ii) conflict with,
or constitute a default (or an event which with notice or lapse of time or both
would become a default) under, or give to others any rights of termination,
amendment, acceleration or cancellation of any material agreement, mortgage,
deed of trust, indenture, note, bond, license, lease agreement, instrument or
obligation to which the Purchaser is a party, (iii) create or impose or lien,
charge or encumbrance on any property of the Purchaser under any agreement or
any commitment to which the Purchaser is party or by which the Purchaser is on
or by which any of its respective properties or assets are bound or (iv) result
in a violation of any law, rule or regulation, or any order, judgment or decree
of any court or governmental agency applicable to the Purchaser or its
properties, except for such conflicts, defaults and violations as would not,
individually or in the aggregate, prohibit or otherwise interfere with the
ability of the Purchaser to enter into and perform its obligations under this
Agreement in any material respect. The Purchaser is not required to obtain any
consent, authorization or order of, or make any filing or registration with, any
court or governmental agency in order for it to execute, deliver or perform any
of its obligations under this Agreement or to purchase the Shares in accordance
with the terms hereof.

          (d)  Information. The Purchaser and its advisors, if any, have been
furnished with all materials relating to the business, finances and operations
of the Company and materials relating to the offer and sale of the Shares which
have been requested by the Purchaser to the extent such information is either
publicly available or not of a material nature. The Purchaser and its advisors,
if any, have been afforded the opportunity to ask questions of the Company. The
Purchaser has sought such accounting, legal and tax advice as it has considered
necessary to make an informed investment decision with respect to its
acquisition of the Shares. Purchaser understands that it (and not the Company)
shall be responsible for its own tax liabilities that may arise as a result of
this investment or the transactions contemplated by this Agreement.

          (e)  Investment Intent. The Purchaser is purchasing the Shares for its
own account for investment and not with a view toward the resale or distribution
thereof to others, and has no intent of undertaking special selling activities
with respect to the Company's Common Stock.

                                  ARTICLE IV

                                   Covenants

     The parties covenant with each other as follows, which covenants are for
the benefit of the party indicated and its or their permitted assignees.

          Section 4.1    Securities. The Company shall notify the Commission and
NASDAQ, if applicable, in accordance with their rules and regulations, of the
transactions contemplated by this Agreement, and shall take all other necessary
action and proceedings as

                                       7
<PAGE>

may be required and permitted by applicable law, rule and regulation, for the
legal and valid issuance of the Shares to the Purchasers or subsequent holders.

          Section 4.2    Registration and Listing. The Company will take all
action necessary to cause its Common Stock to continue to be registered under
Sections 12(b) or 12(g) of the Exchange Act, will comply in all respects with
its reporting and filing obligations under the Exchange Act, and will not take
any action or file any document (whether or not permitted by the Securities Act
or the rules promulgated thereunder) to terminate or suspend such registration
or to terminate or suspend its reporting and filing obligations under the
Exchange Act or Securities Act, except as permitted herein. The Company will
take all action necessary to continue the listing or trading of its Common Stock
and the listing of the Shares purchased by the Purchasers hereunder on the
NASDAQ or any relevant market or system, if applicable, and will comply in all
respects with the Company's reporting, filing and other obligations under the
bylaws or rules of the NASD or any relevant market or system.

          Section 4.3    Compliance with Laws. The Company shall comply, and
cause each subsidiary to comply, with all applicable laws, rules, regulations
and orders, noncompliance with which could reasonably be expected to have a
Material Adverse Effect.

          Section 4.4    Keeping of Records and Books of Account. The Company
shall keep and cause each subsidiary to keep adequate records and books of
account, in which complete entries will be made in accordance with GAAP
consistently applied, reflecting all financial transactions of the Company and
its subsidiaries, and in which, for each fiscal year, all proper reserves for
depreciation, depletion, obsolescence, amortization, taxes, bad debts and other
purposes in connection with its business shall be made.

          Section 4.5    Non-public Information. Neither the Company nor any of
its officers or agents shall disclose any material non-public information about
the Company to the Purchasers and neither the Purchasers nor any of its
affiliates, officers or agents will solicit any material non-public information
from the Company.

          Section 4.6    Prospectus Delivery. Upon Closing, the Company will
deliver to the Purchasers, without charge, in such quantities as reasonably
requested by the Purchasers, copies of each form of Prospectus (and any
amendment or supplement thereto). As soon after the Closing as possible and
thereafter from time to time for such period as in the opinion of counsel for
the Purchasers a prospectus is required by the Securities Act to be delivered in
connection with sales by the Purchasers, the Company will expeditiously deliver
to the Purchasers, without charge, as many copies of the Prospectus (and of any
amendment or supplement thereto) as the Purchasers may reasonably request. The
Company consents to the use of the Prospectus (and of any amendment or
supplement thereto) in accordance with the provisions of the Securities Act and
with the securities or Blue Sky laws of the jurisdictions in which the Shares
may be sold by the Purchasers, in connection with the offering and sale of the
Shares and for such period of time thereafter as the Prospectus is required by
the Securities Act to be delivered in connection with sales of the Shares. If
during such period of time any event shall occur that in the judgment of the
Company or in the opinion of counsel for the Purchasers is required to be set
forth in the Prospectus (as then amended or supplemented) or should be set

                                       8
<PAGE>

forth therein in order to make the statements therein, in the light of the
circumstances under which they were made, not misleading, or if it is necessary
to supplement or amend the Prospectus to comply with the Securities Act or any
other law, the Company will forthwith prepare and file with the Commission an
appropriate supplement or amendment thereto, and will expeditiously furnish to
the Purchasers a reasonable number of copies thereof.

          Section 4.7    Effective Registration Statement. If, at the time this
Agreement is executed and delivered, it is necessary for the Registration
Statement or a post-effective amendment thereto to be declared effective before
the offering of the Shares may commence, the Company will endeavor to cause the
Registration Statement or such post-effective amendment to become effective as
soon as reasonably practicable and will advise the Purchasers promptly and, if
requested by the Purchasers, will confirm such advice in writing, when the
Company receives notice that the Registration Statement or such post-effective
amendment has become effective.

                                   ARTICLE V

                             Conditions to Closing

          Section 5.1    Conditions Precedent to the Obligation of the Company
to Close this Agreement and to Sell the Shares. The obligation hereunder of the
Company to issue and sell the Shares to the Purchasers is subject to the
satisfaction or waiver of each of the conditions set forth below. These
conditions are for the Company's sole benefit and may be waived by the Company
at any time in its sole discretion.

          (a)  Accuracy of the Purchaser's Representations and Warranties. The
Purchaser shall deliver a certificate to the effect that the representations and
warranties of each of the Purchasers shall be true and correct in all material
respects as of the Closing Date with the same effect as though such
representation and warranty had been made on and as of that date.

          (b)  Effective Registration Statement. The Registration Statement
registering the offer and sale of the Shares shall have been declared effective
by the Commission.

          (c)  Performance by the Purchasers. The Purchasers shall have
performed, satisfied and complied in all material respects with all covenants,
agreements and conditions required by this Agreement to be performed, satisfied
or complied with by the Purchasers.

          (d)  No Injunction. No statute, regulation, executive order, decree,
ruling or injunction shall have been enacted, entered, promulgated or endorsed
by any court or governmental authority of competent jurisdiction which prohibits
the consummation of any of the transactions contemplated by this Agreement.

          (e)  No Suspension, Etc. Trading in the Company's Common Stock shall
not be suspended by the Commission or the NASD (except for any suspension of
trading of limited duration agreed to by the Company, which suspension shall be
terminated prior to Closing), and, at any time prior to the Closing, trading in
securities generally as reported on NASDAQ shall not have been suspended or
limited, or minimum prices shall not have been established on securities

                                       9
<PAGE>

whose trades are reported by American Stock Exchange, or on the New York Stock
     Exchange, nor shall a banking moratorium have been declared either by the
     United States or New York State authorities, nor shall there have occurred
     any material outbreak or escalation of hostilities or other national or
     international calamity or crisis of such magnitude in its effect on, or any
     material adverse change in any financial market which, in each case, in the
     judgment of the Company, makes it impracticable or inadvisable to issue the
     Shares.

          (f)  No Proceedings or Litigation. No action, suit or proceeding
before any arbitrator or any governmental authority shall have been commenced,
and no investigation by any governmental authority shall have been threatened,
against the Company or any subsidiary, or any of the officers, directors or
affiliates of the Company or any subsidiary seeking to restrain, prevent or
change the transactions contemplated by this Agreement, or seeking damages in
connection with such transactions.

          (g)  Warrant Agreement. The Purchasers shall have entered into the
Warrant Agreement.

          (h)  Escrow Agreement. The Escrow Agreement shall not have been
terminated and shall be in full force and effect.

          Section 5.2    Conditions Precedent to the Obligation of the
Purchasers to Close this Agreement. The obligation hereunder of the Purchasers
to purchase the Shares set forth opposite the Purchasers' name on Exhibit A is
subject to the satisfaction or waiver, at or before the Closing, of each of the
conditions set forth below. These conditions are for the Purchasers' sole
benefit and may be waived by the Purchasers at any time in their sole
discretion.

          (a)  Performance by the Company. The Company shall have performed,
satisfied and complied in all material respects with all covenants, agreements
and conditions required by this Agreement to be performed, satisfied or complied
with by the Company at or prior to the Closing.

          (b)  No Suspension, Etc. Trading in the Company's Common Stock shall
not be suspended by the Commission or the NASD (except for any suspension of
trading of limited duration agreed to by the Company, which suspension shall be
terminated prior to Closing), and, at any time prior to the Closing, trading in
securities generally as reported on NASDAQ shall not have been suspended or
limited, or minimum prices shall not have been established on securities whose
trades are reported by the American Stock Exchange, or on the New York Stock
Exchange, nor shall a banking moratorium have been declared either by the United
States or New York State authorities, nor shall there have occurred any material
outbreak or escalation of hostilities or other national or international
calamity or crisis of such magnitude in its effect on, or any material adverse
change in any financial market which, in each case, in the judgment of the
Purchasers, makes it impracticable or inadvisable to purchase the Shares.

          (c)  No Injunction. No statute, rule, regulation, executive order,
decree, ruling or injunction shall have been enacted, entered, promulgated or
endorsed by any court or governmental authority of competent jurisdiction which
prohibits the consummation of any of the transactions contemplated by this
Agreement.

                                      10
<PAGE>

          (d)  No Proceedings or Litigation. No action, suit or proceeding
before any arbitrator or any governmental authority shall have been commenced,
and no investigation by any governmental authority shall have been threatened,
against the Company or any subsidiary, or any of the officers, directors or
affiliates of the Company or any subsidiary seeking to restrain, prevent or
change the transactions contemplated by this Agreement, or seeking damages in
connection with such transactions.

          (e)  Opinion of Counsel, Etc. At the Closing, the Purchasers shall
have received an opinion of counsel to the Company, dated the date of Closing,
in the form of Exhibit D hereto, and such other certificates and documents as
the Purchasers or their counsel shall reasonably require incident to the
Closing.

          (f)  Warrant Agreement. The Company shall have entered into the
Warrant Agreement.

          (g)  Escrow Agreement. The Escrow Agreement shall not have been
terminated and shall be in full force and effect.

          (h)  Prospectus Supplement. The Company shall have filed a Prospectus
Supplement registering the Shares pursuant to the Registration Statement on Form
S-3 (Registration Number 333-43788).

          (i)  Credit Agreement Amendment. The Company shall have amended its
Credit Agreement dated April 11, 2000 (the "Credit Agreement"), to the extent
necessary to allow for the purchase and sale of the Shares contemplated by this
Agreement without invoking any mandatory prepayment or other provisions of the
Credit Agreement which may restrict or in anyway limit (i) the ability of the
Company to effectuate the purchase and sale of the Shares or (ii) the use of the
proceeds received by the Company upon the purchase and sale of the Shares.

          (j)  Bank Facility Increase The Company shall have received a written
commitment from the Lenders, as such term is defined in the Credit Agreement,
agreeing to increase the Company's credit facility from $75 million to an amount
not less than $100 million.

          (k)  Accuracy of the Company's Representations and Warranties. The
Company shall deliver a certificate, executed by an officer of the Company, to
the effect that the representations and warranties of the Company shall be true
and correct in all material respects as of the Closing Date with the same effect
as though such representations and warranties had been made on and as of that
date.

                                  ARTICLE VI

                                 Miscellaneous

          Section 6.1    Fees and Expenses. Each of the parties to this
Agreement shall be responsible for the payment of their own fees and expenses
incurred in connection with the preparation, negotiation and execution of this
Agreement and the transactions contemplated hereby whether or not the
transactions contemplated hereby are consummated.

                                      11
<PAGE>

          Section 6.2    Specific Enforcement, Consent to Jurisdiction.

          (a)  The Company and the Purchasers acknowledge and agree that
irreparable damage would occur in the event that any of the provisions of this
Agreement were not performed in accordance with their specific terms or were
otherwise breached. It is accordingly agreed that the parties shall be entitled
to an injunction or injunctions to prevent or cure breaches of the provisions of
this Agreement and to enforce specifically the terms and provisions hereof or
thereof, this being in addition to any other remedy to which any of them may be
entitled by law or equity.

          (b)  Each of the Company and the Purchasers (i) hereby irrevocably
submits to the jurisdiction of the United States District Court and other courts
of the United States sitting in The State of New York for the purposes of any
suit, action or proceeding arising out of or relating to this Agreement and (ii)
hereby waives, and agrees not to assert in any such suit, action or proceeding,
any claim that it is not personally subject to the jurisdiction of such court,
that the suit, action or proceeding is brought in an inconvenient forum or that
the venue of the suit, action or proceeding is improper. Each of the Company and
the Purchasers consent to process being served in any such suit, action or
proceeding by mailing a copy thereof to such party at the address in effect for
notices to it under this Agreement and agree that such service shall constitute
good and sufficient service of process and notice thereof. Nothing in this
Section shall affect or limit any right to serve process in any other manner
permitted by law.

          Section 6.3    Entire Agreement; Amendment. This Agreement contains
the entire understanding of the parties with respect to the matters covered
hereby and, except as specifically set forth herein, neither the Company nor the
Purchasers make any representations, warranty, covenant or undertaking with
respect to such matters. No provision of this Agreement may be waived or amended
other than by a written instrument signed by the party against whom enforcement
of any such amendment or waiver is sought.

          Section 6.4    Notices. Any notice, demand, request, waiver or other
communication required or permitted to be given hereunder shall be in writing
and shall be effective if delivered to the Company in the manner set forth below
to the address or number set forth below and to the Purchasers in the manner set
forth below to the address or number set forth on Exhibit B, in each case (a)
upon hand delivery, by telex (with correct answer back received), telecopy or
facsimile (if delivered on a business day during normal business hours where
such notice is to be received), or the first business day following such
delivery (if delivered other than on a business day during normal business hours
where such notice is to be received) or (b) on the second business day following
the date of mailing by express courier service, fully prepaid, addressed to such
address, or upon actual receipt of such mailing, whichever shall first occur.
The addresses for such communications to the Company shall be:

                                      12
<PAGE>

                         FiberNet Telecom Group, Inc.
                         570 Lexington Avenue
                         New York, New York 10022
                         Tel. No.: (212) 405-6200
                         Fax No.:  (212) 421-8920
                         Attention:  Michael S. Liss,
                                     President and Chief Executive Officer

With copies to:          Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                         Chrysler Center
                         666 Third Avenue
                         New York, New York  10022
                         Tel. No.: (212) 935-3000
                         Fax No.: (212) 983-3115
                         Attention:  Gordon Caplan, Esq.

     Any party hereto may from time to time change its address for notices by
giving at least ten (10) days prior written notice of such changed address to
the other party hereto.

          Section 6.5    Waivers. No waiver by either party of any default with
respect to any provision, condition or requirement of this Agreement shall be
deemed to be a continuing waiver in the future or a waiver of any other
provisions, condition or requirement hereof, nor shall any delay or omission of
any party to exercise any right hereunder in any manner impair the exercise of
any such right accruing to it thereafter.

          Section 6.6    Headings. The article, section and subsection headings
in this Agreement are for convenience only and shall not constitute a part of
this Agreement for any other purpose and shall not be deemed to limit or affect
any of the provisions hereof.

          Section 6.7    Successors and Assigns. The Purchasers may not assign
this Agreement to any person without the prior written consent of the Company,
which consent will not be unreasonably withheld. This Agreement shall be binding
upon and inure to the benefit of the parties and their successors and assigns.
After Closing, the assignment by a party to this Agreement of any rights
hereunder shall not affect the obligations of such party under this Agreement.

          Section 6.8    Governing Law. This Agreement shall be governed by and
construed in accordance with the internal laws of the State of New York, without
giving effect to the choice of law provisions.

          Section 6.9    Survival. The representations and warranties of the
Company and each of the Purchasers contained in Article III and the covenants
contained in Article IV shall survive the execution and delivery hereof and the
Closing until the one (1) year anniversary of the date of the Closing.

                                      13
<PAGE>

          Section 6.10   Counterparts. This Agreement may be executed in any
number of counterparts, all of which taken together shall constitute one and the
same instrument and shall become effective when counterparts have been signed by
each party and delivered to the other parties hereto, it being understood that
all parties need not sign the same counterpart. In the event any signature is
delivered by facsimile transmission, the party using such means of delivery
shall cause four additional executed signature pages to be physically delivered
to the other parties within five days of the execution and delivery hereof.

          Section 6.11   Publicity. Prior to the Closing, neither the Company
nor any Purchaser shall issue any press release or otherwise make any public
statement or announcement with respect to this Agreement or the transactions
contemplated hereby or the existence of this Agreement. Promptly after the
Closing, the Company may issue a press release or otherwise make a public
statement or announcement with respect to this Agreement or the transactions
contemplated hereby or the existence of this Agreement, provided, however, that
in the event such press release contains the identity of any of the Purchasers
or quotes of any of the Purchasers, then prior to issuing any such press
release, making any such public statement or announcement, the Company shall
obtain the prior consent of such Purchaser identified or quoted, which consent
shall not be unreasonably withheld or delayed. Notwithstanding the foregoing, in
the event the Company is required by law, based upon an opinion of the Company's
counsel, to issue a press release or otherwise make a public statement or
announcement with respect to this Agreement prior to or after the Closing, the
Company shall consult with the Purchasers on the form and substance of such
press release or other disclosure.

          Section 6.12   Severability. The provisions of this Agreement are
severable and, in the event that any court of competent jurisdiction shall
determine that any one or more of the provisions or part of the provisions
contained in this Agreement shall, for any reason, be held to be invalid,
illegal or unenforceable in any respect, such invalidity, illegality or
unenforceability shall not affect any other provision or part of a provision of
this Agreement, and this Agreement shall be reformed and construed as if such
invalid or illegal or unenforceable provision, or part of such provision, had
never been contained herein, so that such provisions would be valid, legal and
enforceable to the maximum extent possible.

          Section 6.13   Further Assurances. From and after the date of this
Agreement, upon the request of the Purchasers or the Company, each of the
Company and the Purchasers shall execute and deliver such instrument, documents
and other writings as may be reasonably necessary or desirable to confirm and
carry out and to effectuate fully the intent and purposes of this Agreement.

           [THE REMAINDER OF THIS PAGE IS INTENTIONALLY LEFT BLANK]

                                      14
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed by their respective authorized officers as of the date first above
written.

                                             FIBERNET TELECOM GROUP, INC.

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

                                             [________________________]

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

                                             [________________________]

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

                                      15
<PAGE>

                                   EXHIBIT A

            Number of Shares of Common Stock and Warrants Purchased
<PAGE>

                               EXHIBIT B TO THE
                  COMMON STOCK AND WARRANT PURCHASE AGREEMENT

ESCROW AGREEMENT
<PAGE>

                               EXHIBIT C TO THE
                  COMMON STOCK AND WARRANT PURCHASE AGREEMENT

FORM OF WARRANT AGREEMENT

                                       2
<PAGE>

                               EXHIBIT D TO THE

                  COMMON STOCK AND WARRANT PURCHASE AGREEMENT

MINTZ LEVIN OPINION

                                       3
<PAGE>

                             DISCLOSURE SCHEDULES
                   RELATING TO THE COMMON STOCK AND WARRANT
            PURCHASE AGREEMENT, DATED AS OF EBRUARY 1, 2001 BETWEEN
                       FIBERNET TELECOM GROUP, INC. AND
                         THE PURCHASERS NAMED THEREIN

     ALL SECTION AND SUBSECTION NUMBERS AND LETTERS RELATE AND COINCIDE TO SUCH
NUMBERS AND LETTERS AS SET FORTH  IN THE COMMON STOCK AND WARRANT PURCHASE
AGREEMENT (THE "AGREEMENT").  ANY CAPITALIZED TERMS USED HEREIN WITHOUT
DEFINITION SHALL HAVE THE MEANINGS ASCRIBED TO SUCH TERMS IN THE AGREEMENT.

     ALL REPRESENTATIONS AND WARRANTIES SET FORTH IN THE AGREEMENT ARE MODIFIED
IN THEIR ENTIRETY BY THESE DISCLOSURE SCHEDULES.  THE DISCLOSURES CONTAINED IN
THESE DISCLOSURE SCHEDULES SHALL BE READ IN THEIR ENTIRETY, AND ALL THE
DISCLOSURES SHALL BE READ TOGETHER.
<PAGE>

                              INDEX OF SCHEDULES

Schedule 3.1(e) - Subsidiaries
<PAGE>

                                Schedule 3.1(e)

                                 Subsidiaries
                                 ------------

------------------------------------------------------------------------------
 Subsidiaries of FiberNet          State of Incorporation   Ownership Interest
 Telecom Group, Inc.                  or Organization
------------------------------------------------------------------------------

FiberNet Operations, Inc.                 Delaware                 100%
------------------------------------------------------------------------------

FiberNet Telecom, Inc. (1)                Delaware                 100%
------------------------------------------------------------------------------

FiberNet Equal Access, L.L.C. (2)         New York                 100%
------------------------------------------------------------------------------

Local Fiber, L.L.C. (2)                   New York                 100%
------------------------------------------------------------------------------

Devnet, L.L.C. (3)                        Delaware                 100%
------------------------------------------------------------------------------

(1) FiberNet Operations, Inc. owns 100% of the capital stock.

(2) FiberNet Telecom, Inc. owns 100% of the membership interests.

(3) The FiberNet Telecom Group, Inc. owns 96.386% of the membership interests
and FiberNet Operations, Inc. owns 3.614% of the membership interests.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00019-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00019-of-00352.parquet"}]]