Document:

EXHIBIT 4.4

THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE HEREOF HAVE
NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
"SECURITIES ACT") OR ANY STATE SECURITIES LAWS AND MAY NOT BE SOLD, TRANSFERRED
OR OTHERWISE DISPOSED OF UNLESS REGISTERED UNDER THE SECURITIES ACT AND UNDER
APPLICABLE STATE SECURITIES LAWS OR FIBERNET TELECOM GROUP, INC. SHALL HAVE
RECEIVED AN OPINION OF COUNSEL THAT REGISTRATION OF SUCH SECURITIES UNDER THE
SECURITIES ACT AND UNDER THE PROVISIONS OF APPLICABLE STATE SECURITIES LAWS IS
NOT REQUIRED.

                               WARRANT TO PURCHASE

                             SHARES OF COMMON STOCK

                                       OF

                          FIBERNET TELECOM GROUP, INC.

                            Expires October 30, 2007

No.: W-02-__                                       Number of Shares: ___________
Date of Issuance: October 30, 2002

     FOR VALUE RECEIVED, subject to the provisions hereinafter set forth, the
undersigned, FiberNet Telecom Group, Inc., a Delaware corporation (together with
its successors and assigns, the "Issuer"), hereby certifies that
_______________________________ or its registered assigns is entitled to
subscribe for and purchase, during the Term (as hereinafter defined), up to
____________________________________ (_____________) shares (subject to
adjustment as hereinafter provided) of the duly authorized, validly issued,
fully paid and non-assessable Common Stock of the Issuer, at an exercise price
per share equal to the Warrant Price (as hereinafter defined) then in effect,
subject, however, to the provisions and upon the terms and conditions
hereinafter set forth. Capitalized terms used in this Warrant and not otherwise
defined herein shall have the respective meanings specified in Section 8 hereof.

     1. Term. The right to subscribe for and purchase shares of Warrant Stock
represented hereby shall commence on October 30, 2002 and shall expire at 5:00
p.m., eastern time, on October 30, 2007 (such period being the "Term").

                                      -1-

<PAGE>

     2. Method of Exercise Payment; Issuance of New Warrant; Transfer and
Exchange.

     (a) Time of Exercise. The purchase rights represented by this Warrant may
be exercised in whole or in part during the Term commencing on October 30, 2002
and expiring on October 30, 2007.

     (b) Method of Exercise. The Holder hereof may exercise this Warrant, in
whole or in part, by the surrender of this Warrant (with the exercise form
attached hereto duly executed) at the principal office of the Issuer, and by the
payment to the Issuer of an amount of consideration therefor equal to the
Warrant Price in effect on the date of such exercise multiplied by the number of
shares of Warrant Stock with respect to which this Warrant is then being
exercised, payable at such Holder's election (i) by certified or official bank
check or by wire transfer to an account designated by the Issuer, (ii) by
"cashless exercise" in accordance with the provisions of subsection (c) of this
Section 2, or (iii) by a combination of the foregoing methods of payment
selected by the Holder of this Warrant.

     (c) Cashless Exercise. Notwithstanding any provisions herein to the
contrary, if the Per Share Market Value of one share of Common Stock is greater
than the Warrant Price (at the date of calculation as set forth below), in lieu
of exercising this Warrant by payment of cash, the Holder may exercise this
Warrant by a cashless exercise by surrender of this Warrant at the principal
office of the Issuer together with the properly endorsed Notice of Exercise in
which event the Issuer shall issue to the Holder a number of shares of Common
Stock computed using the following formula:

      X = Y - (A)(Y)
              ------
                 B

Where X =   the number of shares of Common Stock to be issued to the Holder.

      Y =   the number of shares of Common Stock purchasable upon exercise of
            all of the Warrant or, if only a portion of the Warrant is being
            exercised, the portion of the Warrant being exercised.

      A =   the Warrant Price.

      B =   the Per Share Market Value of one share of Common Stock.

     (d) Issuance of Stock Certificates. In the event of any exercise of the
rights represented by this Warrant in accordance with and subject to the terms
and conditions hereof, (i) certificates for the shares of Warrant Stock so
purchased shall be dated the date of such exercise and delivered to the Holder
hereof within a reasonable time, not exceeding three (3) Trading Days after such
exercise or, at the request of the Holder (provided that a registration
statement under the Securities Act qualifying a public offering of the Warrant
Stock is then in effect), issued and delivered to the Depository Trust Company
("DTC") account on the Holder's behalf via the Deposit Withdrawal Agent
Commission System ("DWAC") within a reasonable time, not exceeding three (3)
Trading Days after such exercise, and the Holder hereof shall be deemed for

                                      -2-

<PAGE>

all purposes to be the holder of the shares of Warrant Stock so purchased as of
the date of such exercise and (ii) unless this Warrant has expired, a new
Warrant representing the right to purchase the number of shares of Warrant
Stock, if any, with respect to which this Warrant shall not then have been
exercised (less any amount thereof which shall have been canceled in payment or
partial payment of the Warrant Price as hereinabove provided) shall also be
issued to the Holder hereof at the Issuer's expense within such time.

     (e) Transferability of Warrant. Subject to Section 2(g), this Warrant may
be transferred by a Holder without the consent of the Issuer. If transferred
pursuant to this paragraph and subject to the provisions of subsection (g) of
this Section 2, this Warrant may be transferred on the books of the Issuer by
the Holder hereof in person or by duly authorized attorney, upon surrender of
this Warrant at the principal office of the Issuer, properly endorsed (by the
Holder executing an assignment in the form attached hereto) and upon payment of
any necessary transfer tax or other governmental charge imposed upon such
transfer. This Warrant is exchangeable at the principal office of the Issuer for
Warrants for the purchase of the same aggregate number of shares of Warrant
Stock, each new Warrant to represent the right to purchase such number of shares
of Warrant Stock as the Holder hereof shall designate at the time of such
exchange. All Warrants issued on transfers or exchanges shall be dated the
Original Issue Date and shall be identical with this Warrant except as to the
number of shares of Warrant Stock issuable pursuant hereto.

     (f) Continuing Rights of Holder. The Issuer will, at the time of or at any
time after each exercise of this Warrant, upon the request of the Holder hereof,
acknowledge in writing the extent, if any, of its continuing obligation to
afford to such Holder all rights to which such Holder shall continue to be
entitled after such exercise in accordance with the terms of this Warrant,
provided that if any such Holder shall fail to make any such request, the
failure shall not affect the continuing obligation of the Issuer to afford such
rights to such Holder.

     (g) Compliance with Securities Laws.

          (i) The Holder of this Warrant, by acceptance hereof, acknowledges
     that this Warrant or the shares of Warrant Stock to be issued upon exercise
     hereof are being acquired solely for the Holder's own account and not as a
     nominee for any other party, and for investment, and that the Holder will
     not offer, sell or otherwise dispose of this Warrant or any shares of
     Warrant Stock to be issued upon exercise hereof except pursuant to an
     effective registration statement, or an exemption from registration, under
     the Securities Act and any applicable state securities laws.

          (ii) Except as provided in paragraph (iii) below, this Warrant and all
     certificates representing shares of Warrant Stock issued upon exercise
     hereof shall be stamped or imprinted with a legend in substantially the
     following form:

          THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE
          HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
          AMENDED (THE "SECURITIES ACT") OR ANY STATE

                                      -3-

<PAGE>

          SECURITIES LAWS AND MAY NOT BE SOLD, TRANSFERRED OR OTHERWISE DISPOSED
          OF UNLESS REGISTERED UNDER THE SECURITIES ACT AND UNDER APPLICABLE
          STATE SECURITIES LAWS OR FIBERNET TELECOM GROUP, INC. SHALL HAVE
          RECEIVED AN OPINION OF COUNSEL THAT REGISTRATION OF SUCH SECURITIES
          UNDER THE SECURITIES ACT AND UNDER THE PROVISIONS OF APPLICABLE STATE
          SECURITIES LAWS IS NOT REQUIRED.

          (iii) The restrictions imposed by this subsection (e) upon the
     transfer of this Warrant or the shares of Warrant Stock to be purchased
     upon exercise hereof shall terminate (A) when such securities shall have
     been resold pursuant to an effective registration statement under the
     Securities Act, (B) upon the Issuer's receipt of an opinion of counsel, in
     form and substance reasonably satisfactory to the Issuer, addressed to the
     Issuer to the effect that such restrictions are no longer required to
     ensure compliance with the Securities Act and state securities laws or (C)
     upon the Issuer's receipt of other evidence reasonably satisfactory to the
     Issuer that such registration and qualification under the Securities Act
     and state securities laws are not required. Whenever such restrictions
     shall cease and terminate as to any such securities, the Holder thereof
     shall be entitled to receive from the Issuer (or its transfer agent and
     registrar), without expense (other than applicable transfer taxes, if any),
     new Warrants (or, in the case of shares of Warrant Stock, new stock
     certificates) of like tenor not bearing the applicable legend required by
     paragraph (ii) above relating to the Securities Act and state securities
     laws.

     3. Stock Fully Paid; Adjustments; Reservation and Listing of Shares;
Covenants.

     (a) Stock Fully Paid; Other Adjustments. The Issuer represents, warrants,
covenants and agrees that all shares of Warrant Stock which may be issued upon
the exercise of this Warrant or otherwise hereunder will, upon issuance, be duly
authorized, validly issued, fully paid and non-assessable and free from all
taxes, liens and charges created by or through the Issuer. The Issuer also
covenants and agrees that during the period within which this Warrant may be
exercised, the Issuer will at all times have authorized and reserved for the
purpose of the issue upon exercise of this Warrant a sufficient number of shares
of Common Stock to provide for the exercise of this Warrant. The Issuer further
represents and warrants that the issuance of this Warrant and the Warrant Stock
will not trigger an adjustment of the exercise price or the number of securities
issuable upon the exercise, conversion or exchange, of any exercisable,
convertible, or exchangeable security issued on the Original Issue Date.

     (b) Reservation. If any shares of Common Stock required to be reserved for
issuance upon exercise of this Warrant or as otherwise provided hereunder
require registration or qualification with any governmental authority under any
federal or state law before such shares may be so issued, the Issuer will in
good faith use its reasonable best efforts as expeditiously as possible at its
expense to cause such shares to be duly registered or qualified. If the Issuer
shall list any shares of Common Stock on any securities exchange or market it
will, at its expense, list thereon, maintain and increase when necessary such
listing, of, all shares of Warrant Stock from

                                      -4-

<PAGE>

time to time issued upon exercise of this Warrant or as otherwise provided
hereunder (provided that such Warrant Stock has been registered pursuant to a
registration statement under the Securities Act then in effect), and, to the
extent permissible under the applicable securities exchange rules, all unissued
shares of Warrant Stock which are at any time issuable hereunder, so long as any
shares of Common Stock shall be so listed. The Issuer will also so list on each
securities exchange or market, and will maintain such listing of, any other
securities which the Holder of this Warrant shall be entitled to receive upon
the exercise of this Warrant if at the time any securities of the same class
shall be listed on such securities exchange or market by the Issuer.

     (c) Covenants. The Issuer shall not by any action including, without
limitation, amending the Certificate of Incorporation or the by-laws of the
Issuer, or through any reorganization, transfer of assets, consolidation,
merger, dissolution, issue or sale of securities or any other action, avoid or
seek to avoid the observance or performance of any of the terms of this Warrant,
but will at all times in good faith assist in the carrying out of all such terms
and in the taking of all such actions as may be necessary or appropriate to
protect the rights of the Holder hereof against dilution (to the extent
specifically provided herein) or impairment. Without limiting the generality of
the foregoing, the Issuer will (i) not permit the par value, if any, of its
Common Stock to exceed the then effective Warrant Price, (ii) not amend or
modify any provision of the Certificate of Incorporation or by-laws of the
Issuer in any manner that would adversely affect the rights of the Holders of
the Warrants, (iii) take all such action as may be reasonably necessary in order
that the Issuer may validly and legally issue fully paid and nonassessable
shares of Common Stock, free and clear of any liens, claims, encumbrances and
restrictions (other than as provided herein) upon the exercise of this Warrant,
and (iv) use its reasonable best efforts to obtain all such authorizations,
exemptions or consents from any public regulatory body having jurisdiction
thereof as may be reasonably necessary to enable the Issuer to perform its
obligations under this Warrant.

     (d) Loss, Theft, Destruction of Warrants. Upon receipt of evidence
reasonably satisfactory to the Issuer of the ownership of and the loss, theft,
destruction or mutilation of any Warrant and, in the case of any such loss,
theft or destruction, upon receipt of indemnity or security reasonably
satisfactory to the Issuer or, in the case of any such mutilation, upon
surrender and cancellation of such Warrant, the Issuer will make and deliver, in
lieu of such lost, stolen, destroyed or mutilated Warrant, a new Warrant of like
tenor and representing the right to purchase the same number of shares of Common
Stock.

     4. Adjustment of Warrant Price and Warrant Share Number. The number of
shares of Common Stock for which this Warrant is exercisable, and the price at
which such shares may be purchased upon exercise of this Warrant, shall be
subject to adjustment from time to time as set forth in this Section 4. The
Issuer shall give the Holder notice of any event described below which requires
an adjustment pursuant to this Section 4 in accordance with Section 5.
Notwithstanding anything in this Section 4 to the contrary, no adjustments shall
be made to the number of shares for which this Warrant is exercisable or the
price at which such shares may be purchased upon exercise of this Warrant as a
result of any registered exchange offer to be effected by the Issuer to holders
of all of its warrants outstanding prior to the Original Issue Date, as
described in the Lender Common Stock Purchase Agreement.

                                      -5-

<PAGE>

     (a) Recapitalization, Reorganization, Reclassification, Consolidation,
Merger or Sale.

          (i) In case the Issuer after the Original Issue Date shall do any of
     the following (each, a "Triggering Event"): (a) consolidate with or merge
     into any other Person and the Issuer shall not be the continuing or
     surviving corporation of such consolidation or merger, or (b) permit any
     other Person to consolidate with or merge into the Issuer and the Issuer
     shall be the continuing or surviving Person but, in connection with such
     consolidation or merger, any Capital Stock of the Issuer shall be changed
     into or exchanged for Securities of any other Person or cash or any other
     property, or (c) transfer all or substantially all of its properties or
     assets to any other Person, or (d) effect a capital reorganization or
     reclassification of its Capital Stock, then, and in the case of each such
     Triggering Event, proper provision shall be made so that, upon the basis
     and the terms and in the manner provided in this Warrant, the Holder of
     this Warrant shall be entitled upon the exercise hereof at any time after
     the consummation of such Triggering Event, to the extent this Warrant is
     not exercised prior to such Triggering Event, to receive at the Warrant
     Price in effect at the time immediately prior to the consummation of such
     Triggering Event in lieu of the Common Stock issuable upon the exercise of
     this Warrant prior to such Triggering Event, the Securities, cash and
     property to which such Holder would have been entitled upon the
     consummation of such Triggering Event if such Holder had exercised the
     rights represented by this Warrant immediately prior thereto, subject to
     adjustments (subsequent to such corporate action) as nearly equivalent as
     possible to the adjustments provided for elsewhere in this Section 4.

          (ii) Notwithstanding anything contained in this Warrant to the
     contrary, a Triggering Event shall not be deemed to have occurred if, prior
     to the consummation thereof, each Person (other than the Issuer) which may
     be required to deliver any Securities, cash or property upon the exercise
     of this Warrant as provided herein shall assume, by written instrument
     delivered to, and reasonably satisfactory to, the Holder of this Warrant,
     (A) the obligations of the Issuer under this Warrant (and if the Issuer
     shall survive the consummation of such Triggering Event, such assumption
     shall be in addition to, and shall not release the Issuer from, any
     continuing obligations of the Issuer under this Warrant) and (B) the
     obligation to deliver to such Holder such shares of Securities, cash or
     property as, in accordance with the foregoing provisions of this subsection
     (a), such Holder shall be entitled to receive, and such Person shall have
     similarly delivered to such Holder an opinion of counsel for such Person,
     which counsel shall be reasonably satisfactory to such Holder, or in the
     alternative, a written acknowledgement executed by the President or Chief
     Financial Officer of such Person, stating that this Warrant shall
     thereafter continue in full force and effect and the terms hereof
     (including, without limitation, all of the provisions of this subsection
     (a)) shall be applicable to the Securities, cash or property which such
     Person may be required to deliver upon any exercise of this Warrant or the
     exercise of any rights pursuant hereto.

     (b) Stock Dividends, Subdivisions and Combinations. If at any time the
Issuer shall:

                                      -6-

<PAGE>

          (i) take a record of the holders of its Common Stock for the purpose
     of entitling them to receive a dividend payable in, or other distribution
     of, shares of Common Stock,

          (ii) subdivide its outstanding shares of Common Stock into a larger
     number of shares of Common Stock, or

          (iii) combine its outstanding shares of Common Stock into a smaller
     number of shares of Common Stock,

then (1) the number of shares of Common Stock for which this Warrant is
exercisable immediately after the occurrence of any such event shall be adjusted
to equal the number of shares of Common Stock which a record holder of the same
number of shares of Common Stock for which this Warrant is exercisable
immediately prior to the occurrence of such event would own or be entitled to
receive after the happening of such event, and (2) the Warrant Price then in
effect shall be adjusted to equal (A) the Warrant Price then in effect
multiplied by the number of shares of Common Stock for which this Warrant is
exercisable immediately prior to the adjustment divided by (B) the number of
shares of Common Stock for which this Warrant is exercisable immediately after
such adjustment.

     (c) Certain Other Distributions. If at any time the Issuer shall take a
record of the holders of its Common Stock for the purpose of entitling them to
receive any dividend or other distribution of:

          (i) cash (other than a cash dividend payable out of earnings or earned
     surplus legally available for the payment of dividends under the laws of
     the jurisdiction of incorporation of the Issuer),

          (ii) any evidences of its indebtedness, any shares of stock of any
     class or any other securities or property of any nature whatsoever (other
     than cash, Common Stock Equivalents or Additional Shares of Common Stock),
     or

          (iii) any warrants or other rights to subscribe for or purchase any
     evidences of its indebtedness, any shares of stock of any class or any
     other securities or property of any nature whatsoever (other than cash,
     Common Stock Equivalents or Additional Shares of Common Stock),

then (1) the number of shares of Common Stock for which this Warrant is
exercisable shall be adjusted to equal the product of the number of shares of
Common Stock for which this Warrant is exercisable immediately prior to such
adjustment multiplied by a fraction (A) the numerator of which shall be the Per
Share Market Value of Common Stock at the date of taking such record and (B) the
denominator of which shall be such Per Share Market Value minus the amount
allocable to one share of Common Stock of any such cash so distributable and of
the fair value (as determined in good faith by the Board of Directors of the
Issuer and supported by an opinion from an investment banking firm of recognized
national standing acceptable to (but not affiliated with) the Holder) of any and
all such evidences of indebtedness, shares of stock, other securities

                                       -7-

<PAGE>

or property or warrants or other subscription or purchase rights so
distributable, and (2) the Warrant Price then in effect shall be adjusted to
equal (A) the Warrant Price then in effect multiplied by the number of shares of
Common Stock for which this Warrant is exercisable immediately prior to the
adjustment divided by (B) the number of shares of Common Stock for which this
Warrant is exercisable immediately after such adjustment. A reclassification of
the Common Stock (other than a change in par value, or from par value to no par
value or from no par value to par value) into shares of Common Stock and shares
of any other class of stock shall be deemed a distribution by the Issuer to the
holders of its Common Stock of such shares of such other class of stock within
the meaning of this Section 4(c) and, if the outstanding shares of Common Stock
shall be changed into a larger or smaller number of shares of Common Stock as a
part of such reclassification, such change shall be deemed a subdivision or
combination, as the case may be, of the outstanding shares of Common Stock
within the meaning of Section 4(b).

     (d) Issuance of Additional Shares of Common Stock.

          (i) In the event the Issuer shall at any time following the six month
     anniversary of the Original Issue Date issue any Additional Shares of
     Common Stock (otherwise than as provided in the foregoing subsections (b)
     through (c) of this Section 4), at a price per share less than the Warrant
     Price then in effect or without consideration, then the Warrant Price upon
     each such issuance shall be adjusted to that price determined by
     multiplying the Warrant Price then in effect by a fraction:

               (A) the numerator of which shall be equal to the sum of (x) the
          number of shares of Outstanding Common Stock immediately prior to the
          issuance of such Additional Shares of Common Stock plus (y) the number
          of shares of Common Stock which the aggregate consideration for the
          total number of such Additional Shares of Common Stock so issued would
          purchase at a price per share equal to the Warrant Price then in
          effect, and

               (B) the denominator of which shall be equal to the number of
          shares of Outstanding Common Stock immediately after the issuance of
          such Additional Shares of Common Stock.

          (ii) The provisions of paragraph (i) of Section 4(d) shall not apply
     to any issuance of Additional Shares of Common Stock for which an
     adjustment is provided under Section 4(b) or 4(c). No adjustment of the
     Warrant Price or the number of shares of Common Stock for which this
     Warrant shall be exercisable shall be made under paragraph (i) of Section
     4(d) upon the issuance of any Additional Shares of Common Stock which are
     issued pursuant to the exercise of any Common Stock Equivalents, if any
     such adjustment shall previously have been made upon the issuance of such
     Common Stock Equivalents (or upon the issuance of any warrant or other
     rights therefor) pursuant to Section 4(e) or Section 4(f).

     (e) Issuance of Warrants or Other Rights. If at any time the Issuer shall
take a record of the holders of its Common Stock for the purpose of entitling
them to receive a distribution of, or shall in any manner (whether directly or
by assumption in a merger in which the Issuer is the surviving corporation)
issue or sell, any Common Stock Equivalents (or issue any warrant or

                                      -8-

<PAGE>

other rights therefor), whether or not the rights to exchange or convert
thereunder are immediately exercisable, and the price per share for which Common
Stock is issuable upon the exercise of such Common Stock Equivalents (or any
warrant or other rights therefor) shall be less than the Warrant Price in effect
immediately prior to the time of such issue or sale, then the number of shares
for which this Warrant is exercisable and the Warrant Price then in effect shall
be adjusted as provided in Section 4(d) on the basis that the maximum number of
Additional Shares of Common Stock issuable pursuant to all such Common Stock
Equivalents (or upon the issuance of any warrant or other rights therefor) shall
be deemed to have been issued and outstanding and the Issuer shall have received
all of the consideration payable therefor, if any, as of the date of the actual
issuance of such Common Stock Equivalents, warrants or other rights. No
adjustments of the Warrant Price then in effect or the amount of Warrant Stock
for which this Warrant is exercisable shall be made upon the actual issue of
such Common Stock or of such Common Stock Equivalents upon exercise of such
warrants or other rights or upon the actual issue of such Common Stock upon such
conversion or exchange of such Common Stock Equivalents.

     (f) Issuance of Common Stock Equivalents. If at any time the Issuer shall
take a record of the holders of its Common Stock for the purpose of entitling
them to receive a distribution of, or shall in any manner (whether directly or
by assumption in a merger in which the Issuer is the surviving corporation)
issue or sell, any Common Stock Equivalents, whether or not the rights to
exchange or convert thereunder are immediately exercisable, and the price per
share for which Common Stock is issuable upon such conversion or exchange shall
be less than the Warrant Price in effect immediately prior to the time of such
issue or sale, then the number of shares of Common Stock for which this Warrant
is exercisable and the Warrant Price then in effect shall be adjusted as
provided in Section 4(d) on the basis that the maximum number of Additional
Shares of Common Stock issuable upon the conversion or exchange of all such
Common Stock Equivalents shall be deemed to have been issued and outstanding and
the Issuer shall have received all of the consideration payable therefor, if
any, as of the date of actual issuance of such Common Stock Equivalents. No
further adjustment of the number of shares of Common Stock for which this
Warrant is exercisable and the Warrant Price then in effect shall be made under
this Section 4(f) upon the issuance of any Common Stock Equivalents which are
issued pursuant to the exercise of any warrants or other subscription or
purchase rights therefor, if any such adjustment shall previously have been made
upon the issuance of such warrants or other rights pursuant to Section 4(e). No
further adjustments of the number of shares of Common Stock for which this
Warrant is exercisable and the Warrant Price then in effect shall be made upon
the actual issue of such Common Stock upon conversion or exchange of such Common
Stock Equivalents.

     (g) Superseding Adjustment. If, at any time after any adjustment of the
number of shares of Common Stock for which this Warrant is exercisable and the
Warrant Price then in effect shall have been made pursuant to Section 4(e) or
Section 4(f) as the result of any issuance of warrants, other rights or Common
Stock Equivalents, and (i) such warrants or other rights, or the right of
conversion or exchange in such other Common Stock Equivalents, shall expire, and
all or a portion of such warrants or other rights, or the right of conversion or
exchange with respect to all or a portion of such other Common Stock
Equivalents, as the case may be shall not have been exercised, or (ii) the
consideration per share for which shares of Common Stock are

                                      -9-

<PAGE>

issuable pursuant to such Common Stock Equivalents, shall be increased solely by
virtue of provisions therein contained for an automatic increase in such
consideration per share upon the occurrence of a specified date or event, then
for each outstanding Warrant such previous adjustment shall be rescinded and
annulled and the Additional Shares of Common Stock which were deemed to have
been issued by virtue of the computation made in connection with the adjustment
so rescinded and annulled shall no longer be deemed to have been issued by
virtue of such computation. Upon the occurrence of an event set forth above in
this Section 4(g), there shall be a recomputation made of the effect of such
Common Stock Equivalents on the basis of: (i) treating the number of Additional
Shares of Common Stock or other property, if any, theretofore actually issued or
issuable pursuant to the previous exercise of any such warrants or other rights
or any such right of conversion or exchange, as having been issued on the date
or dates of any such exercise and for the consideration actually received and
receivable therefor, and (ii) treating any such Common Stock Equivalents which
then remain outstanding as having been granted or issued immediately after the
time of such increase of the consideration per share for which shares of Common
Stock or other property are issuable under such Common Stock Equivalents;
whereupon a new adjustment of the number of shares of Common Stock for which
this Warrant is exercisable and the Warrant Price then in effect shall be made,
which new adjustment shall supersede the previous adjustment so rescinded and
annulled.

     (h) Purchase of Common Stock by the Issuer. If the Issuer at any time while
this Warrant is outstanding shall, directly or indirectly through a Subsidiary
or otherwise, purchase, redeem or otherwise acquire any shares of Common Stock
at a price per share greater than the Per Share Market Value, then the Warrant
Price upon each such purchase, redemption or acquisition shall be adjusted to
that price determined by multiplying such Warrant Price by a fraction (i) the
numerator of which shall be the number of shares of Outstanding Common Stock
immediately prior to such purchase, redemption or acquisition minus the number
of shares of Common Stock which the aggregate consideration for the total number
of such shares of Common Stock so purchased, redeemed or acquired would purchase
at the Per Share Market Value; and (ii) the denominator of which shall be the
number of shares of Outstanding Common Stock immediately after such purchase,
redemption or acquisition. For the purposes of this subsection (h), the date as
of which the Per Share Market Price shall be computed shall be the earlier of
(x) the date on which the Issuer shall enter into a firm contract for the
purchase, redemption or acquisition of such Common Stock, or (y) the date of
actual purchase, redemption or acquisition of such Common Stock. For the
purposes of this subsection (h), a purchase, redemption or acquisition of a
Common Stock Equivalent shall be deemed to be a purchase of the underlying
Common Stock, and the computation herein required shall be made on the basis of
the full exercise, conversion or exchange of such Common Stock Equivalent on the
date as of which such computation is required hereby to be made, whether or not
such Common Stock Equivalent is actually exercisable, convertible or
exchangeable on such date.

     (i) Other Provisions applicable to Adjustments under this Section. The
following provisions shall be applicable to the making of adjustments of the
number of shares of Common Stock for which this Warrant is exercisable and the
Warrant Price then in effect provided for in this Section 4:

          (i) Computation of Consideration. To the extent that any Additional
     Shares

                                      -10-

<PAGE>

     of Common Stock or any Common Stock Equivalents (or any warrants or other
     rights therefor) shall be issued for cash consideration, the consideration
     received by the Issuer therefor shall be the amount of the cash received by
     the Issuer therefor, or, if such Additional Shares of Common Stock or
     Common Stock Equivalents are offered by the Issuer for subscription, the
     subscription price, or, if such Additional Shares of Common Stock or Common
     Stock Equivalents are sold to underwriters or dealers for public offering
     without a subscription offering, the initial public offering price (in any
     such case subtracting any amounts paid or receivable for accrued interest
     or accrued dividends and without taking into account any compensation,
     discounts or expenses paid or incurred by the Issuer for and in the
     underwriting of, or otherwise in connection with, the issuance thereof). To
     the extent that such issuance shall be for a consideration other than cash,
     then, except as herein otherwise expressly provided, the amount of such
     consideration shall be deemed to be the fair value of such consideration at
     the time of such issuance as determined in good faith by the Board of
     Directors of the Issuer. In case any Additional Shares of Common Stock or
     any Common Stock Equivalents (or any warrants or other rights therefor)
     shall be issued in connection with any merger in which the Issuer issues
     any securities, the amount of consideration therefor shall be deemed to be
     the fair value, as determined in good faith by the Board of Directors of
     the Issuer, of such portion of the assets and business of the nonsurviving
     corporation as such Board in good faith shall determine to be attributable
     to such Additional Shares of Common Stock, Common Stock Equivalents, or any
     warrants or other rights therefor, as the case may be. The consideration
     for any Additional Shares of Common Stock issuable pursuant to any warrants
     or other rights to subscribe for or purchase the same shall be the
     consideration received by the Issuer for issuing such warrants or other
     rights plus the additional consideration payable to the Issuer upon
     exercise of such warrants or other rights. The consideration for any
     Additional Shares of Common Stock issuable pursuant to the terms of any
     Common Stock Equivalents shall be the consideration received by the Issuer
     for issuing warrants or other rights to subscribe for or purchase such
     Common Stock Equivalents, plus the consideration paid or payable to the
     Issuer in respect of the subscription for or purchase of such Common Stock
     Equivalents, plus the additional consideration, if any, payable to the
     Issuer upon the exercise, conversion or exchange of such Common Stock
     Equivalents. In case of the issuance at any time of any Additional Shares
     of Common Stock or Common Stock Equivalents in payment or satisfaction of
     any dividends upon any class of stock other than Common Stock, the Issuer
     shall be deemed to have received for such Additional Shares of Common Stock
     or Common Stock Equivalents a consideration equal to the amount of such
     dividend so paid or satisfied.

          (ii) When Adjustments to Be Made. The adjustments required by this
     Section 4 shall be made whenever and as often as any specified event
     requiring an adjustment shall occur, except that any adjustment of the
     number of shares of Common Stock for which this Warrant is exercisable that
     would otherwise be required may be postponed (except in the case of a
     subdivision or combination of shares of the Common Stock, as provided for
     in Section 4(b)) up to, but not beyond the date of exercise if such
     adjustment either by itself or with other adjustments not previously made
     adds or subtracts less than one percent (1%) of the shares of Common Stock
     for which this Warrant is exercisable immediately prior to the making of
     such adjustment. Any adjustment representing a change of less than such
     minimum amount (except as aforesaid) which is postponed shall be carried
     forward and made as soon as such adjustment, together with other
     adjustments required by this Section 4 and not previously made, would
     result

                                      -11-

<PAGE>

     in a minimum adjustment or on the date of exercise. For the purpose of any
     adjustment, any specified event shall be deemed to have occurred at the
     close of business on the date of its occurrence.

          (iii) Fractional Interests. In computing adjustments under this
     Section 4, fractional interests in Common Stock shall be taken into account
     to the nearest one one-hundredth (1/100th) of a share.

          (iv) When Adjustment Not Required. If the Issuer shall take a record
     of the holders of its Common Stock for the purpose of entitling them to
     receive a dividend or distribution or subscription or purchase rights and
     shall, thereafter and before the distribution to stockholders thereof,
     legally abandon its plan to pay or deliver such dividend, distribution,
     subscription or purchase rights, then thereafter no adjustment shall be
     required by reason of the taking of such record and any such adjustment
     previously made in respect thereof shall be rescinded and annulled.

     (j) Form of Warrant after Adjustments. The form of this Warrant need not be
changed because of any adjustments in the Warrant Price or the number and kind
of Securities purchasable upon the exercise of this Warrant.

     (k) Escrow of Warrant Stock. If after any property becomes distributable
pursuant to this Section 4 by reason of the taking of any record of the holders
of Common Stock, but prior to the occurrence of the event for which such record
is taken, and the Holder exercises this Warrant, any shares of Common Stock
issuable upon exercise by reason of such adjustment shall be deemed the last
shares of Common Stock for which this Warrant is exercised (notwithstanding any
other provision to the contrary herein) and such shares or other property shall
be held in escrow for the Holder by the Issuer to be issued to the Holder upon
and to the extent that the event actually takes place, upon payment of the
current Warrant Price. Notwithstanding any other provision to the contrary
herein, if the event for which such record was taken fails to occur or is
rescinded, then such escrowed shares shall be cancelled by the Issuer and
escrowed property returned.

     5. Notice of Adjustments. Whenever the Warrant Price or Warrant Share
Number shall be adjusted pursuant to Section 4 hereof (for purposes of this
Section 5, each an "adjustment"), the Issuer shall cause its Chief Financial
Officer to prepare and execute a certificate setting forth, in reasonable
detail, the event requiring the adjustment, the amount of the adjustment, the
method by which such adjustment was calculated (including a description of the
basis on which the Board made any determination hereunder), and the Warrant
Price and Warrant Share Number after giving effect to such adjustment, and shall
cause copies of such certificate to be delivered to the Holder of this Warrant
promptly after each adjustment. Any dispute between the Issuer and the Holder of
this Warrant with respect to the matters set forth in such certificate may at
the option of the Holder of this Warrant be submitted to one of the national
accounting firms currently known as the "big four" selected by the Holder,
provided that the Issuer shall have ten (10) days after receipt of notice from
such Holder of its selection of such firm to object thereto, in which case such
Holder shall select another such firm and the Issuer shall have no such right of
objection. The firm selected by the Holder of this Warrant as

                                      -12-

<PAGE>

provided in the preceding sentence shall be instructed to deliver a written
opinion as to such matters to the Issuer and such Holder within thirty (30) days
after submission to it of such dispute. Such opinion shall be final and binding
on the parties hereto.

     6. Fractional Shares. No fractional shares of Warrant Stock will be issued
in connection with any exercise hereof, but in lieu of such fractional shares,
the Issuer shall make a cash payment therefor equal in amount to the product of
the applicable fraction multiplied by the Per Share Market Value then in effect.

     7. Intentionally Omitted.

     8. Definitions. For the purposes of this Warrant, the following terms have
the following meanings:

          "Additional Shares of Common Stock" means all shares of Common Stock
     issued by the Issuer after the Original Issue Date, and all shares of Other
     Common, if any, issued by the Issuer after the Original Issue Date, except:
     (1) shares of Common Stock to be issued to strategic partners and/or in
     connection with a strategic merger or acquisition; (2) up to 100,441,177
     shares of Common Stock (as adjusted for any stock dividends, combinations,
     splits, recapitalizations and the like) or the issuance of options to
     purchase shares of Common Stock to employees, officers, directors,
     consultants and vendors in accordance with the Issuer's equity incentive
     policies; (3) the issuance of securities pursuant to an underwritten public
     offering of the Issuer's securities; (4) the conversion or exercise of
     Convertible Securities issued or outstanding on or prior to the date
     hereof; (5) the Warrant Stock; (6) any registered exchange offer to be
     effected by the Issuer to holders of all of its warrants outstanding prior
     to the Original Issue Date, as described in the Lender Common Stock
     Purchase Agreement; (7) the issuance of securities pursuant to the Lender
     Common Stock Purchase Agreement; (8) the issuance of securities pursuant to
     the Exchange Agreements, and (9) New Equity Common Stock and New Equity
     Warrants, in each case for so long as the exercise price of and number of
     securities acquirable pursuant to the New Equity Warrants are not
     adjustable in connection with the issuance of, or as a result of the
     operation of the terms of, this Warrant.

          "Board" shall mean the Board of Directors of the Issuer.

          "Capital Stock" means and includes (i) any and all shares, interests,
     participations or other equivalents of or interests in (however designated)
     corporate stock, including, without limitation, shares of preferred or
     preference stock, (ii) all partnership interests (whether general or
     limited) in any Person which is a partnership, (iii) all membership
     interests or limited liability company interests in any limited liability
     company, and (iv) all equity or ownership interests in any Person of any
     other type.

          "Certificate of Incorporation" means the Certificate of Incorporation
     of the Issuer as in effect on the Original Issue Date, and as hereafter
     from time to time amended, modified, supplemented or restated in accordance
     with the terms hereof and thereof and pursuant to applicable law.

                                      -13-

<PAGE>

          "Common Stock" means the Common Stock, par value $.001 per share, of
     the Issuer and any other Capital Stock into which such stock may hereafter
     be changed.

          "Common Stock Equivalent" means any Convertible Security or warrant,
     option or other right to subscribe for or purchase any Additional Shares of
     Common Stock or any Convertible Security.

          "Convertible Securities" means evidences of Indebtedness, shares of
     Capital Stock or other Securities which are or may be at any time
     convertible into or exchangeable for Additional Shares of Common Stock. The
     term "Convertible Security" means one of the Convertible Securities.

          "Exchange Agreements" means, collectively, the Nortel Note Exchange
     Agreement, the Series H Share Exchange Agreement, the Series J Share
     Exchange Agreement, and any agreement entered into after the date hereof
     between SDS Merchant Fund, L.P. and the Issuer providing for the conversion
     of the entire aggregate principal amount, all accrued and unpaid interest
     thereon and all other amounts payable in respect of the promissory note
     issued by the Issuer to SDS Merchant Fund, L.P. in March, 2002 in an
     initial principal amount of $2,000,000.

          "Governmental Authority" means any governmental, regulatory or
     self-regulatory entity, department, body, official, authority, commission,
     board, agency or instrumentality, whether federal, state or local, and
     whether domestic or foreign.

          "Holders" mean the Persons who shall from time to time own any
     Warrant. The term "Holder" means one of the Holders.

          "Independent Appraiser" means a nationally recognized or major
     regional investment banking firm or firm of independent certified public
     accountants of recognized standing (which may be the firm that regularly
     examines the financial statements of the Issuer) that is regularly engaged
     in the business of appraising the Capital Stock or assets of corporations
     or other entities as going concerns, and which is not affiliated with
     either the Issuer or the Holder of any Warrant.

          "Issuer" means FiberNet Telecom Group, Inc., a Delaware corporation,
     and its successors.

          "Lender Common Stock Purchase Agreement" shall mean that certain
     Common Stock and Warrant Purchase Agreement dated as of October 30, 2002,
     by and among the Company and the lenders under the Company's senior credit
     facility.

          "Majority Holders" means at any time the Holders of Warrants
     exercisable for a majority of the shares of Warrant Stock issuable under
     the Warrants at the time outstanding.

                                      -14-

<PAGE>

          "Nasdaq" means the Nasdaq SmallCap Market.

          "New Equity Common Stock" means the shares of Common Stock issued by
     the Company pursuant to the terms of the Common Stock Purchase Agreement,
     dated as of October 30, 2002, by and among the Company and the purchasers
     listed on Schedule I thereto.

          "New Equity Warrants" means the warrants issued by the Company
     pursuant to the terms of the Common Stock Purchase Agreement, dated as of
     October 30, 2002, by and among the Company and the purchasers listed on
     Schedule I thereto, and the securities issuable upon exercise of such
     warrants.

          "Nortel Note Exchange Agreement" means the Note Exchange Agreement,
     dated as of October 30, 2002, by and between the Company and SDS Merchant
     Fund, L.P. as in effect on the date hereof, pursuant to which the
     promissory note issued by the Company to Nortel Networks Inc. on December
     7, 2001, will be surrendered to the Company in exchange for shares of
     Common Stock.

          "Original Issue Date" means October 30, 2002.

          "OTC Bulletin Board" means the over-the-counter electronic bulletin
     board.

          "Other Common" means any other Capital Stock of the Issuer of any
     class which shall be authorized at any time after the date of this Warrant
     (other than Common Stock) and which shall have the right to participate in
     the distribution of earnings and assets of the Issuer without limitation as
     to amount.

          "Outstanding Common Stock" means, at any given time, the aggregate
     amount of outstanding shares of Common Stock, assuming full exercise,
     conversion or exchange (as applicable) of all options, warrants and other
     Securities which are convertible into or exercisable or exchangeable for,
     and any right to subscribe for, shares of Common Stock that are outstanding
     at such time.

          "Person" means an individual, corporation, limited liability company,
     partnership, joint stock company, trust, unincorporated organization, joint
     venture, Governmental Authority or other entity of whatever nature.

          "Per Share Market Value" means on any particular date (a) the closing
     bid price per share of the Common Stock on such date on Nasdaq or another
     registered national stock exchange on which the Common Stock is then
     listed, or if there is no such price on such date, then the closing bid
     price on such exchange or quotation system on the date nearest preceding
     such date, or (b) if the Common Stock is not listed then on Nasdaq or any
     registered national stock exchange, the closing bid price for a share of
     Common Stock in the over-the-counter market, as reported by the OTC
     Bulletin Board or in the National Quotation Bureau Incorporated or similar
     organization (or agency succeeding to its functions of reporting prices) at
     the close of business on such date, or (c) if the Common Stock is not then
     reported by the OTC Bulletin Board or the National Quotation

                                      -15-

<PAGE>

     Bureau Incorporated (or similar organization or agency succeeding to its
     functions of reporting prices), then the "Pink Sheet" quote for a share of
     the Common Stock on such date, or if there is no such quote on such date,
     then the "Pink Sheet" quote on the date nearest preceding such date, as
     determined in good faith by the Holder, or (d) if the Common Stock is not
     then publicly traded the fair market value of a share of Common Stock as
     determined by an Independent Appraiser selected in good faith by the
     Majority Holders; provided, however, that the Issuer, after receipt of the
     determination by such Independent Appraiser, shall have the right to select
     an additional Independent Appraiser, in which case, the fair market value
     shall be equal to the average of the determinations by each such
     Independent Appraiser; and provided, further that all determinations of the
     Per Share Market Value shall be appropriately adjusted for any stock
     dividends, stock splits or other similar transactions. The determination of
     fair market value by an Independent Appraiser shall be based upon the fair
     market value of the Issuer determined on a going concern basis as between a
     willing buyer and a willing seller and taking into account all relevant
     factors determinative of value, and shall be final and binding on all
     parties. In determining the fair market value of any shares of Common
     Stock, no consideration shall be given to any restrictions on transfer of
     the Common Stock imposed by agreement or by federal or state securities
     laws, or to the existence or absence of, or any limitations on, voting
     rights.

          "Purchase Agreement" means the Common Stock Purchase Agreement dated
     as of October 30, 2002, among the Issuer and the investors party thereto.

          "Securities" means any debt or equity securities of the Issuer,
     whether now or hereafter authorized, any instrument convertible into or
     exchangeable for Securities or a Security, and any option, warrant or other
     right to purchase or acquire any Security. "Security" means one of the
     Securities.

          "Securities Act" means the Securities Act of 1933, as amended, or any
     similar federal statute then in effect.

          "Series H Share Exchange Agreement" means the Share Exchange
     Agreement, dated as of October 30, 2002, by and among the Company and each
     of the purchasers whose names appear on the signature pages thereto,
     pursuant to which the Company will issue Common Stock in exchange for all
     of its issued and outstanding shares of Series H Preferred Stock.

          "Series J Share Exchange Agreement" means the Series J-1 Share
     Exchange Agreement, dated as of October 30, 2002, by and among the Company
     and each of the purchasers whose names appear on the signature pages
     thereto, pursuant to which the Company will issue Common Stock in exchange
     for all of its issued and outstanding shares of Series J-1 Preferred Stock.

          "Subsidiary" means any corporation at least 50% of whose outstanding
     Voting Stock shall at the time be owned directly or indirectly by the
     Issuer or by one or more of its Subsidiaries, or by the Issuer and one or
     more of its Subsidiaries.

                                      -16-

<PAGE>

          "Term" has the meaning specified in Section 1 hereof.

          "Trading Day" means (a) a day on which the Common Stock is traded on
     Nasdaq, or (b) if the Common Stock is not listed on Nasdaq, a day on which
     the Common Stock is traded on any other registered national stock exchange,
     or (c) if the Common Stock is not traded on any other registered national
     stock exchange, a day on which the Common Stock is traded on the OTC
     Bulletin Board, or (d) if the Common Stock is not traded on the OTC
     Bulletin Board, a day on which the Common Stock is quoted in the
     over-the-counter market as reported by the National Quotation Bureau
     Incorporated (or any similar organization or agency succeeding its
     functions of reporting prices); provided, however, that in the event that
     the Common Stock is not listed or quoted as set forth in (a), (b), (c) or
     (d) hereof, then Trading Day shall mean any day except Saturday, Sunday and
     any day which shall be a legal holiday or a day on which banking
     institutions in the State of New York are authorized or required by law or
     other government action to close.

          "Voting Stock" means, as applied to the Capital Stock of any
     corporation, Capital Stock of any class or classes (however designated)
     having ordinary voting power for the election of a majority of the members
     of the Board of Directors (or other governing body) of such corporation,
     other than Capital Stock having such power only by reason of the happening
     of a contingency.

          "Warrants" means the Warrants issued and sold pursuant to the Lender
     Common Stock Purchase Agreement, including, without limitation, this
     Warrant, and any other warrants of like tenor issued in substitution or
     exchange for any thereof pursuant to the provisions of Section 2(c), 2(d)
     or 2(e) hereof or of any of such other Warrants.

          "Warrant Price" initially means U.S. $0.12, as such price may be
     adjusted from time to time as shall result from the adjustments specified
     in this Warrant, including Section 4 hereto.

          "Warrant Share Number" means at any time the aggregate number of
     shares of Warrant Stock which may at such time be purchased upon exercise
     of this Warrant, after giving effect to all prior adjustments and increases
     to such number made or required to be made under the terms hereof.

          "Warrant Stock" means Common Stock issuable upon exercise of any
     Warrant or Warrants or otherwise issuable pursuant to any Warrant or
     Warrants.

     9. Other Notices. In case at any time:

          (A)  the Issuer shall make any distributions to the holders of Common
               Stock; or

                                      -17-

<PAGE>

          (B)  the Issuer shall authorize the granting to all holders of its
               Common Stock of rights to subscribe for or purchase any shares of
               Capital Stock of any class or other rights; or

          (C)  there shall be any reclassification of the Capital Stock of the
               Issuer; or

          (D)  there shall be any capital reorganization by the Issuer; or

          (E)  there shall be any (i) consolidation or merger involving the
               Issuer or (ii) sale, transfer or other disposition of all or
               substantially all of the Issuer's property, assets or business
               (except a merger or other reorganization in which the Issuer
               shall be the surviving corporation and its shares of Capital
               Stock shall continue to be outstanding and unchanged and except a
               consolidation, merger, sale, transfer or other disposition
               involving a wholly-owned Subsidiary); or

          (F)  there shall be a voluntary or involuntary dissolution,
               liquidation or winding-up of the Issuer or any partial
               liquidation of the Issuer or distribution to holders of Common
               Stock;

then, in each of such cases, the Issuer shall give written notice to the Holder
of the date on which (i) the books of the Issuer shall close or a record shall
be taken for such dividend, distribution or subscription rights or (ii) such
reorganization, reclassification, consolidation, merger, disposition,
dissolution, liquidation or winding-up, as the case may be, shall take place.
Such notice also shall specify the date as of which the holders of Common Stock
of record shall participate in such dividend, distribution or subscription
rights, or shall be entitled to exchange their certificates for Common Stock for
securities or other property deliverable upon such reorganization,
reclassification, consolidation, merger, disposition, dissolution, liquidation
or winding-up, as the case may be. Such notice shall be given at least twenty
(20) days prior to the action in question and not less than ten (10) days prior
to the record date or the date on which the Issuer's transfer books are closed
in respect thereto. This Warrant entitles the Holder to receive copies of all
financial and other information distributed or required to be distributed to the
holders of the Common Stock.

     10. Amendment and Waiver. Any term, covenant, agreement or condition in
this Warrant may be amended, or compliance therewith may be waived (either
generally or in a particular instance and either retroactively or
prospectively), by a written instrument or written instruments executed by the
Issuer and the Majority Holders; provided, however, that no such amendment or
waiver shall reduce the Warrant Share Number, increase the Warrant Price,
shorten the period during which this Warrant may be exercised or modify any
provision of this Section 10 without the consent of the Holder of this Warrant.

                                      -18-

<PAGE>

     11. Governing Law. THIS WARRANT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT GIVING EFFECT TO
PRINCIPLES OF CONFLICTS OF LAW.

     12. Notices. Any and all notices or other communications or deliveries
required or permitted to be provided hereunder shall be in writing and shall be
deemed given and effective on the earlier of (i) the date of transmission, if
such notice or communication is delivered via facsimile at the facsimile
telephone number specified for notice prior to 5:00 p.m., eastern time, on a
Trading Day, (ii) the Trading Day after the date of transmission, if such notice
or communication is delivered via facsimile at the facsimile telephone number
specified for notice later than 5:00 p.m., eastern time, on any date and earlier
than 11:59 p.m., eastern time, on such date, (iii) the Trading Day following the
date of mailing, if sent by nationally recognized overnight courier service or
(iv) actual receipt by the party to whom such notice is required to be given.
The addresses for such communications shall be with respect to the Holder of
this Warrant or of Warrant Stock issued pursuant hereto, addressed to such
Holder at its last known address or facsimile number appearing on the books of
the Issuer maintained for such purposes, or with respect to the Issuer,
addressed to:

                        FiberNet Telecom Group, Inc.
                        570 Lexington Avenue
                        New York, New York 10022
                        Attention: President
                        Tel. No.: (212) 405-6200
                        Fax No.:  (212) 421-8860

Copies of notices to a Holder shall be sent to Latham & Watkins, 885 Third
Avenue New York, New York 10022 Attention: John N. Toufanian, Esq. Facsimile:
(212) 751-4864. Any party hereto may from time to time change its address for
notices by giving at least ten (10) days written notice of such changed address
to the other party hereto.

     13. Warrant Agent. The Issuer may, by written notice to each Holder of this
Warrant, appoint an agent having an office in New York, New York for the purpose
of issuing shares of Warrant Stock on the exercise of this Warrant pursuant to
subsection (b) of Section 2 hereof, exchanging this Warrant pursuant to
subsection (d) of Section 2 hereof or replacing this Warrant pursuant to
subsection (d) of Section 3 hereof, or any of the foregoing, and thereafter any
such issuance, exchange or replacement, as the case may be, shall be made at
such office by such agent.

     14. Remedies. The Issuer stipulates that the remedies at law of the Holder
of this Warrant in the event of any default or threatened default by the Issuer
in the performance of or compliance with any of the terms of this Warrant are
not and will not be adequate and that, to the fullest extent permitted by law,
such terms may be specifically enforced by a decree for the specific performance
of any agreement contained herein or by an injunction against a violation of any
of the terms hereof or otherwise.

                                      -19-

<PAGE>

     15. Successors and Assigns. This Warrant and the rights evidenced hereby
shall inure to the benefit of and be binding upon the successors and assigns of
the Issuer, the Holder hereof and (to the extent provided herein) the holders of
Warrant Stock issued pursuant hereto, and shall be enforceable by any such
Holder or holder of Warrant Stock.

     16. Modification and Severability. If, in any action before any court or
agency legally empowered to enforce any provision contained herein, any
provision hereof is found to be unenforceable, then such provision shall be
deemed modified to the extent necessary to make it enforceable by such court or
agency. If any such provision is not enforceable as set forth in the preceding
sentence, the unenforceability of such provision shall not affect the other
provisions of this Warrant, but this Warrant shall be construed as if such
unenforceable provision had never been contained herein.

     17. Headings. The headings of the Sections of this Warrant are for
convenience of reference only and shall not, for any purpose, be deemed a part
of this Warrant.

                                      -20-

<PAGE>

     IN WITNESS WHEREOF, the Issuer has executed this Warrant as of the day and
year first above written.

                                        FIBERNET TELECOM GROUP, INC.

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

                                      -21-

<PAGE>

                                                                  EXECUTION COPY

                                  EXERCISE FORM

                          FIBERNET TELECOM GROUP, INC.

The undersigned _______________, pursuant to the provisions of the within
Warrant, hereby elects to purchase _____ shares of Common Stock of FiberNet
Telecom Group, Inc. covered by the within Warrant.

Dated: _________________                Signature   ___________________________

                                        Address     ___________________________
                                                    ___________________________

                                   ASSIGNMENT

FOR VALUE RECEIVED, _________________ hereby sells, assigns and transfers unto
__________________ the within Warrant and all rights evidenced thereby and does
irrevocably constitute and appoint _____________, attorney, to transfer the said
Warrant on the books of the within named corporation.

Dated: _________________                Signature   ___________________________

                                        Address     ___________________________
                                                    ___________________________

                               PARTIAL ASSIGNMENT

FOR VALUE RECEIVED, _________________ hereby sells, assigns and transfers unto
__________________ the right to purchase _________ shares of Warrant Stock
evidenced by the within Warrant together with all rights therein, and does
irrevocably constitute and appoint ___________________, attorney, to transfer
that part of the said Warrant on the books of the within named corporation.

Dated: _________________                Signature   ___________________________

                                        Address     ___________________________
                                                    ___________________________

                           FOR USE BY THE ISSUER ONLY:

This Warrant No. W-___ canceled (or transferred or exchanged) this _____ day of
___________, _____, shares of Common Stock issued therefor in the name of
_______________, Warrant No. W-_____ issued for ____ shares of Common Stock in
the name of _______________.

                                      -22-EXHIBIT 4.5

THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE HEREOF HAVE
NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
"SECURITIES ACT") OR ANY STATE SECURITIES LAWS AND MAY NOT BE SOLD, TRANSFERRED
OR OTHERWISE DISPOSED OF UNLESS REGISTERED UNDER THE SECURITIES ACT AND UNDER
APPLICABLE STATE SECURITIES LAWS OR FIBERNET TELECOM GROUP, INC. SHALL HAVE
RECEIVED AN OPINION OF ITS COUNSEL THAT REGISTRATION OF SUCH SECURITIES UNDER
THE SECURITIES ACT AND UNDER THE PROVISIONS OF APPLICABLE STATE SECURITIES LAWS
IS NOT REQUIRED.

                               WARRANT TO PURCHASE

                             SHARES OF COMMON STOCK

                                       OF

                          FIBERNET TELECOM GROUP, INC.

                            Expires October 30, 2007

No.: W-02-__                                       Number of Shares: ___________
Date of Issuance: October 30, 2002

     FOR VALUE RECEIVED, subject to the provisions hereinafter set forth, the
undersigned, FiberNet Telecom Group, Inc., a Delaware corporation (together with
its successors and assigns, the "Issuer"), hereby certifies that
_______________________________ or its registered assigns is entitled to
subscribe for and purchase, during the Term (as hereinafter defined), up to
____________________________________ (_____________) shares (subject to
adjustment as hereinafter provided) of the duly authorized, validly issued,
fully paid and non-assessable Common Stock of the Issuer, at an exercise price
per share equal to the Warrant Price then in effect, subject, however, to the
provisions and upon the terms and conditions hereinafter set forth. Capitalized
terms used in this Warrant and not otherwise defined herein shall have the
respective meanings specified in Section 8 hereof.

     1. Term. The right to subscribe for and purchase shares of Warrant Stock
represented hereby shall commence on October 30, 2002 and shall expire at 5:00
p.m., eastern time, on October 30, 2007 (such period being the "Term").

     2. Method of Exercise Payment; Issuance of New Warrant; Transfer and
Exchange.

     (a) Time of Exercise. The purchase rights represented by this Warrant may
be exercised in whole or in part during the Term commencing on October 30, 2002
and expiring on October 30, 2007.

                                      -1-

<PAGE>

     (b) Method of Exercise. The Holder hereof may exercise this Warrant, in
whole or in part, by the surrender of this Warrant (with the exercise form
attached hereto duly executed) at the principal office of the Issuer, and by the
payment to the Issuer of an amount of consideration therefor equal to the
Warrant Price in effect on the date of such exercise multiplied by the number of
shares of Warrant Stock with respect to which this Warrant is then being
exercised, payable at such Holder's election (i) by certified or official bank
check or by wire transfer to an account designated by the Issuer, (ii) by
"cashless exercise" in accordance with the provisions of subsection (c) of this
Section 2, but only when a registration statement under the Securities Act
qualifying a public offering of the Warrant Stock is not then in effect, or
(iii) by a combination of the foregoing methods of payment selected by the
Holder of this Warrant.

     (c) Cashless Exercise. Notwithstanding any provisions herein to the
contrary, if (ii) the Per Share Market Value of one share of Common Stock is
greater than the Warrant Price (at the date of calculation as set forth below)
and (ii) a registration statement under the Securities Act qualifying a public
offering of the Warrant Stock is not then in effect, in lieu of exercising this
Warrant by payment of cash, the Holder may exercise this Warrant by a cashless
exercise and shall receive the number of shares of Common Stock equal to an
amount (as determined below) by surrender of this Warrant at the principal
office of the Issuer together with the properly endorsed Notice of Exercise in
which event the Issuer shall issue to the Holder a number of shares of Common
Stock computed using the following formula:

      X = Y - (A)(Y)
              ------
                 B

Where X =   the number of shares of Common Stock to be issued to the Holder.

      Y =   the number of shares of Common Stock purchasable upon exercise of
            all of the Warrant or, if only a portion of the Warrant is being
            exercised, the portion of the Warrant being exercised.

      A =   the Warrant Price.

      B =   the Per Share Market Value of one share of Common Stock.

     (d) Issuance of Stock Certificates. In the event of any exercise of the
rights represented by this Warrant in accordance with and subject to the terms
and conditions hereof, (i) certificates for the shares of Warrant Stock so
purchased shall be dated the date of such exercise and delivered to the Holder
hereof within a reasonable time, not exceeding three (3) Trading Days after such
exercise or, at the request of the Holder (provided that a registration
statement under the Securities Act qualifying a public offering of the Warrant
Stock is then in effect), issued and delivered to the Depository Trust Company
("DTC") account on the Holder's behalf via the Deposit Withdrawal Agent
Commission System ("DWAC") within a reasonable time, not exceeding three (3)
Trading Days after such exercise, and the Holder hereof shall be deemed for all
purposes to be the holder of the shares of Warrant Stock so purchased as of the
date of such

                                      -2-

<PAGE>

exercise and (ii) unless this Warrant has expired, a new Warrant representing
the number of shares of Warrant Stock, if any, with respect to which this
Warrant shall not then have been exercised (less any amount thereof which shall
have been canceled in payment or partial payment of the Warrant Price as
hereinabove provided) shall also be issued to the Holder hereof at the Issuer's
expense within such time.

     (e) Transferability of Warrant. Subject to Section 2(g), this Warrant may
be transferred by a Holder without the consent of the Issuer. If transferred
pursuant to this paragraph and subject to the provisions of subsection (g) of
this Section 2, this Warrant may be transferred on the books of the Issuer by
the Holder hereof in person or by duly authorized attorney, upon surrender of
this Warrant at the principal office of the Issuer, properly endorsed (by the
Holder executing an assignment in the form attached hereto) and upon payment of
any necessary transfer tax or other governmental charge imposed upon such
transfer. This Warrant is exchangeable at the principal office of the Issuer for
Warrants for the purchase of the same aggregate number of shares of Warrant
Stock, each new Warrant to represent the right to purchase such number of shares
of Warrant Stock as the Holder hereof shall designate at the time of such
exchange. All Warrants issued on transfers or exchanges shall be dated the
Original Issue Date and shall be identical with this Warrant except as to the
number of shares of Warrant Stock issuable pursuant hereto.

     (f) Continuing Rights of Holder. The Issuer will, at the time of or at any
time after each exercise of this Warrant, upon the request of the Holder hereof,
acknowledge in writing the extent, if any, of its continuing obligation to
afford to such Holder all rights to which such Holder shall continue to be
entitled after such exercise in accordance with the terms of this Warrant,
provided that if any such Holder shall fail to make any such request, the
failure shall not affect the continuing obligation of the Issuer to afford such
rights to such Holder.

     (g) Compliance with Securities Laws.

          (i) The Holder of this Warrant, by acceptance hereof, acknowledges
     that this Warrant or the shares of Warrant Stock to be issued upon exercise
     hereof are being acquired solely for the Holder's own account and not as a
     nominee for any other party, and for investment, and that the Holder will
     not offer, sell or otherwise dispose of this Warrant or any shares of
     Warrant Stock to be issued upon exercise hereof except pursuant to an
     effective registration statement, or an exemption from registration, under
     the Securities Act and any applicable state securities laws.

          (ii) Except as provided in paragraph (iii) below, this Warrant and all
     certificates representing shares of Warrant Stock issued upon exercise
     hereof shall be stamped or imprinted with a legend in substantially the
     following form:

          THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE
          HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
          AMENDED (THE "SECURITIES ACT") OR ANY STATE

                                      -3-

<PAGE>

          SECURITIES LAWS AND MAY NOT BE SOLD, TRANSFERRED OR OTHERWISE DISPOSED
          OF UNLESS REGISTERED UNDER THE SECURITIES ACT AND UNDER APPLICABLE
          STATE SECURITIES LAWS OR FIBERNET TELECOM GROUP, INC. SHALL HAVE
          RECEIVED AN OPINION OF ITS COUNSEL THAT REGISTRATION OF SUCH
          SECURITIES UNDER THE SECURITIES ACT AND UNDER THE PROVISIONS OF
          APPLICABLE STATE SECURITIES LAWS IS NOT REQUIRED.

          (iii) The restrictions imposed by this subsection (e) upon the
     transfer of this Warrant or the shares of Warrant Stock to be purchased
     upon exercise hereof shall terminate (A) when such securities shall have
     been resold pursuant to an effective registration statement under the
     Securities Act, (B) upon the Issuer's receipt of an opinion of counsel, in
     form and substance reasonably satisfactory to the Issuer, addressed to the
     Issuer to the effect that such restrictions are no longer required to
     ensure compliance with the Securities Act and state securities laws or (C)
     upon the Issuer's receipt of other evidence reasonably satisfactory to the
     Issuer that such registration and qualification under the Securities Act
     and state securities laws are not required. Whenever such restrictions
     shall cease and terminate as to any such securities, the Holder thereof
     shall be entitled to receive from the Issuer (or its transfer agent and
     registrar), without expense (other than applicable transfer taxes, if any),
     new Warrants (or, in the case of shares of Warrant Stock, new stock
     certificates) of like tenor not bearing the applicable legend required by
     paragraph (ii) above relating to the Securities Act and state securities
     laws.

     3. Stock Fully Paid; Reservation and Listing of Shares; Covenants.

     (a) Stock Fully Paid. The Issuer represents, warrants, covenants and agrees
that all shares of Warrant Stock which may be issued upon the exercise of this
Warrant or otherwise hereunder will, upon issuance, be duly authorized, validly
issued, fully paid and non-assessable and free from all taxes, liens and charges
created by or through Issuer. The Issuer further covenants and agrees that
during the period within which this Warrant may be exercised, the Issuer will at
all times have authorized and reserved for the purpose of the issue upon
exercise of this Warrant a sufficient number of shares of Common Stock to
provide for the exercise of this Warrant.

     (b) Reservation. If any shares of Common Stock required to be reserved for
issuance upon exercise of this Warrant or as otherwise provided hereunder
require registration or qualification with any governmental authority under any
federal or state law before such shares may be so issued, the Issuer will in
good faith use its reasonable best efforts as expeditiously as possible at its
expense to cause such shares to be duly registered or qualified. If the Issuer
shall list any shares of Common Stock on any securities exchange or market it
will, at its expense, list thereon, maintain and increase when necessary such
listing, of, all shares of Warrant Stock from time to time issued upon exercise
of this Warrant or as otherwise provided hereunder (provided that such Warrant
Stock has been registered pursuant to a registration statement under the

                                      -4-

<PAGE>

Securities Act then in effect), and, to the extent permissible under the
applicable securities exchange rules, all unissued shares of Warrant Stock which
are at any time issuable hereunder, so long as any shares of Common Stock shall
be so listed. The Issuer will also so list on each securities exchange or
market, and will maintain such listing of, any other securities which the Holder
of this Warrant shall be entitled to receive upon the exercise of this Warrant
if at the time any securities of the same class shall be listed on such
securities exchange or market by the Issuer.

     (c) Covenants. The Issuer shall not by any action including, without
limitation, amending the Certificate of Incorporation or the by-laws of the
Issuer, or through any reorganization, transfer of assets, consolidation,
merger, dissolution, issue or sale of securities or any other action, avoid or
seek to avoid the observance or performance of any of the terms of this Warrant,
but will at all times in good faith assist in the carrying out of all such terms
and in the taking of all such actions as may be necessary or appropriate to
protect the rights of the Holder hereof against dilution (to the extent
specifically provided herein) or impairment. Without limiting the generality of
the foregoing, the Issuer will (i) not permit the par value, if any, of its
Common Stock to exceed the then effective Warrant Price, (ii) not amend or
modify any provision of the Certificate of Incorporation or by-laws of the
Issuer in any manner that would adversely affect the rights of the Holders of
the Warrants, (iii) take all such action as may be reasonably necessary in order
that the Issuer may validly and legally issue fully paid and nonassessable
shares of Common Stock, free and clear of any liens, claims, encumbrances and
restrictions (other than as provided herein) upon the exercise of this Warrant,
and (iv) use its reasonable best efforts to obtain all such authorizations,
exemptions or consents from any public regulatory body having jurisdiction
thereof as may be reasonably necessary to enable the Issuer to perform its
obligations under this Warrant.

     (d) Loss, Theft, Destruction of Warrants. Upon receipt of evidence
satisfactory to the Issuer of the ownership of and the loss, theft, destruction
or mutilation of any Warrant and, in the case of any such loss, theft or
destruction, upon receipt of indemnity or security satisfactory to the Issuer
or, in the case of any such mutilation, upon surrender and cancellation of such
Warrant, the Issuer will make and deliver, in lieu of such lost, stolen,
destroyed or mutilated Warrant, a new Warrant of like tenor and representing the
right to purchase the same number of shares of Common Stock.

     4. Adjustment of Warrant Price and Warrant Share Number. The number of
shares of Common Stock for which this Warrant is exercisable, and the price at
which such shares may be purchased upon exercise of this Warrant, shall be
subject to adjustment from time to time as set forth in this Section 4. The
Issuer shall give the Holder notice of any event described below which requires
an adjustment pursuant to this Section 4 in accordance with Section 5.
Notwithstanding anything in Section 4 to the contrary, no adjustments shall be
made to the number of shares for which this Warrant is exercisable or the price
at which such shares may be purchased upon exercise of this Warrant as a result
of any registered exchange offer to be effected by the Issuer to holders of all
of its warrants outstanding prior to the Original Issue Date, as described in
the Lender Common Stock Purchase Agreement.

                                      -5-

<PAGE>

     (a) Recapitalization, Reorganization, Reclassification, Consolidation,
Merger or Sale.

          (i) In case the Issuer after the Original Issue Date shall do any of
     the following (each, a "Triggering Event"): (a) consolidate with or merge
     into any other Person and the Issuer shall not be the continuing or
     surviving corporation of such consolidation or merger, or (b) permit any
     other Person to consolidate with or merge into the Issuer and the Issuer
     shall be the continuing or surviving Person but, in connection with such
     consolidation or merger, any Capital Stock of the Issuer shall be changed
     into or exchanged for Securities of any other Person or cash or any other
     property, or (c) transfer all or substantially all of its properties or
     assets to any other Person, or (d) effect a capital reorganization or
     reclassification of its Capital Stock, then, and in the case of each such
     Triggering Event, proper provision shall be made so that, upon the basis
     and the terms and in the manner provided in this Warrant, the Holder of
     this Warrant shall be entitled upon the exercise hereof at any time after
     the consummation of such Triggering Event, to the extent this Warrant is
     not exercised prior to such Triggering Event, to receive at the Warrant
     Price in effect at the time immediately prior to the consummation of such
     Triggering Event in lieu of the Common Stock issuable upon such exercise of
     this Warrant prior to such Triggering Event, the Securities, cash and
     property to which such Holder would have been entitled upon the
     consummation of such Triggering Event if such Holder had exercised the
     rights represented by this Warrant immediately prior thereto, subject to
     adjustments (subsequent to such corporate action) as nearly equivalent as
     possible to the adjustments provided for elsewhere in this Section 4.

          (ii) Notwithstanding anything contained in this Warrant to the
     contrary, a Triggering Event shall not be deemed to have occurred if, prior
     to the consummation thereof, each Person (other than the Issuer) which may
     be required to deliver any Securities, cash or property upon the exercise
     of this Warrant as provided herein shall assume, by written instrument
     delivered to, and reasonably satisfactory to, the Holder of this Warrant,
     (A) the obligations of the Issuer under this Warrant (and if the Issuer
     shall survive the consummation of such Triggering Event, such assumption
     shall be in addition to, and shall not release the Issuer from, any
     continuing obligations of the Issuer under this Warrant) and (B) the
     obligation to deliver to such Holder such shares of Securities, cash or
     property as, in accordance with the foregoing provisions of this subsection
     (a), such Holder shall be entitled to receive, and such Person shall have
     similarly delivered to such Holder an opinion of counsel for such Person,
     which counsel shall be reasonably satisfactory to such Holder, or in the
     alternative, a written acknowledgement executed by the President or Chief
     Financial Officer of the Company, stating that this Warrant shall
     thereafter continue in full force and effect and the terms hereof
     (including, without limitation, all of the provisions of this subsection
     (a)) shall be applicable to the Securities, cash or property which such
     Person may be required to deliver upon any exercise of this Warrant or the
     exercise of any rights pursuant hereto.

     (b) Stock Dividends, Subdivisions and Combinations. If at any time the
Issuer shall:

                                      -6-

<PAGE>

          (i) take a record of the holders of its Common Stock for the purpose
     of entitling them to receive a dividend payable in, or other distribution
     of, shares of Common Stock,

          (ii) subdivide its outstanding shares of Common Stock into a larger
     number of shares of Common Stock, or

          (iii) combine its outstanding shares of Common Stock into a smaller
     number of shares of Common Stock,

then (1) the number of shares of Common Stock for which this Warrant is
exercisable immediately after the occurrence of any such event shall be adjusted
to equal the number of shares of Common Stock which a record holder of the same
number of shares of Common Stock for which this Warrant is exercisable
immediately prior to the occurrence of such event would own or be entitled to
receive after the happening of such event, and (2) the Warrant Price then in
effect shall be adjusted to equal (A) the Warrant Price then in effect
multiplied by the number of shares of Common Stock for which this Warrant is
exercisable immediately prior to the adjustment divided by (B) the number of
shares of Common Stock for which this Warrant is exercisable immediately after
such adjustment.

     (c) Certain Other Distributions. If at any time the Issuer shall take a
record of the holders of its Common Stock for the purpose of entitling them to
receive any dividend or other distribution of:

          (i) cash (other than a cash dividend payable out of earnings or earned
     surplus legally available for the payment of dividends under the laws of
     the jurisdiction of incorporation of the Issuer),

          (ii) any evidences of its indebtedness, any shares of stock of any
     class or any other securities or property of any nature whatsoever (other
     than cash, Common Stock Equivalents or Additional Shares of Common Stock),
     or

          (iii) any warrants or other rights to subscribe for or purchase any
     evidences of its indebtedness, any shares of stock of any class or any
     other securities or property of any nature whatsoever (other than cash,
     Common Stock Equivalents or Additional Shares of Common Stock),

then (1) the number of shares of Common Stock for which this Warrant is
exercisable shall be adjusted to equal the product of the number of shares of
Common Stock for which this Warrant is exercisable immediately prior to such
adjustment multiplied by a fraction (A) the numerator of which shall be the Per
Share Market Value of Common Stock at the date of taking such record and (B) the
denominator of which shall be such Per Share Market Value minus the amount
allocable to one share of Common Stock of any such cash so distributable and of
the fair value (as determined in good faith by the Board of Directors of the
Issuer and supported by an opinion from an investment banking firm of recognized
national standing acceptable to (but not affiliated

                                      -7-

<PAGE>

with) the Holder) of any and all such evidences of indebtedness, shares of
stock, other securities or property or warrants or other subscription or
purchase rights so distributable, and (2) the Warrant Price then in effect shall
be adjusted to equal (A) the Warrant Price then in effect multiplied by the
number of shares of Common Stock for which this Warrant is exercisable
immediately prior to the adjustment divided by (B) the number of shares of
Common Stock for which this Warrant is exercisable immediately after such
adjustment. A reclassification of the Common Stock (other than a change in par
value, or from par value to no par value or from no par value to par value) into
shares of Common Stock and shares of any other class of stock shall be deemed a
distribution by the Issuer to the holders of its Common Stock of such shares of
such other class of stock within the meaning of this Section 4(c) and, if the
outstanding shares of Common Stock shall be changed into a larger or smaller
number of shares of Common Stock as a part of such reclassification, such change
shall be deemed a subdivision or combination, as the case may be, of the
outstanding shares of Common Stock within the meaning of Section 4(b).

     (d) Issuance of Additional Shares of Common Stock.

          (i) In the event the Issuer shall at any time following the six month
     anniversary of the Original Issue Date issue any Additional Shares of
     Common Stock (otherwise than as provided in the foregoing subsections (b)
     through (c) of this Section 4), at a price per share less than the Warrant
     Price then in effect or without consideration, then the Warrant Price upon
     each such issuance shall be adjusted to that price determined by
     multiplying the Warrant Price then in effect by a fraction:

               (A) the numerator of which shall be equal to the sum of (x) the
          number of shares of Outstanding Common Stock immediately prior to the
          issuance of such Additional Shares of Common Stock plus (y) the number
          of shares of Common Stock which the aggregate consideration for the
          total number of such Additional Shares of Common Stock so issued would
          purchase at a price per share equal to the Warrant Price then in
          effect, and

               (B) the denominator of which shall be equal to the number of
          shares of Outstanding Common Stock immediately after the issuance of
          such Additional Shares of Common Stock.

          (ii) The provisions of paragraph (i) of Section 4(d) shall not apply
     to any issuance of Additional Shares of Common Stock for which an
     adjustment is provided under Section 4(b) or 4(c). No adjustment of the
     number of shares of Common Stock for which this Warrant shall be
     exercisable shall be made under paragraph (i) of Section 4(d) upon the
     issuance of any Additional Shares of Common Stock which are issued pursuant
     to the exercise of any Common Stock Equivalents, if any such adjustment
     shall previously have been made upon the issuance of such Common Stock
     Equivalents (or upon the issuance of any warrant or other rights therefor)
     pursuant to Section 4(e) or Section 4(f).

     (e) Issuance of Warrants or Other Rights. If at any time the Issuer shall
take a record of the holders of its Common Stock for the purpose of entitling
them to receive a distribution of, or shall in any manner (whether directly or
by assumption in a merger in which the Issuer is the

                                      -8-

<PAGE>

surviving corporation) issue or sell, any Common Stock Equivalents (or issue any
warrant or other rights therefor), whether or not the rights to exchange or
convert thereunder are immediately exercisable, and the price per share for
which Common Stock is issuable upon the exercise of such Common Stock
Equivalents (or any warrant or other rights therefor) shall be less than the
Warrant Price in effect immediately prior to the time of such issue or sale,
then the number of shares for which this Warrant is exercisable and the Warrant
Price then in effect shall be adjusted as provided in Section 4(d) on the basis
that the maximum number of Additional Shares of Common Stock issuable pursuant
to all such Common Stock Equivalents (or upon the issuance of any warrant or
other rights therefor) shall be deemed to have been issued and outstanding and
the Issuer shall have received all of the consideration payable therefor, if
any, as of the date of the actual issuance of such warrants or other rights. No
adjustments of the Warrant Price then in effect or the number of Warrant Shares
for which this Warrant is exercisable shall be made upon the actual issue of
such Common Stock or of such Common Stock Equivalents upon exercise of such
warrants or other rights or upon the actual issue of such Common Stock upon such
conversion or exchange of such Common Stock Equivalents.

     (f) Issuance of Common Stock Equivalents. If at any time the Issuer shall
take a record of the holders of its Common Stock for the purpose of entitling
them to receive a distribution of, or shall in any manner (whether directly or
by assumption in a merger in which the Issuer is the surviving corporation)
issue or sell, any Common Stock Equivalents, whether or not the rights to
exchange or convert thereunder are immediately exercisable, and the price per
share for which Common Stock is issuable upon such conversion or exchange shall
be less than the Warrant Price in effect immediately prior to the time of such
issue or sale, then the number of shares of Common Stock for which this Warrant
is exercisable and the Warrant Price then in effect shall be adjusted as
provided in Section 4(d) on the basis that the maximum number of Additional
Shares of Common Stock necessary to effect the conversion or exchange of all
such Common Stock Equivalents shall be deemed to have been issued and
outstanding and the Issuer shall have received all of the consideration payable
therefor, if any, as of the date of actual issuance of such Common Stock
Equivalents. No further adjustment of the number of shares of Common Stock for
which this Warrant is exercisable and the Warrant Price then in effect shall be
made under this Section 4(f) upon the issuance of any Common Stock Equivalents
which are issued pursuant to the exercise of any warrants or other subscription
or purchase rights therefor, if any such adjustment shall previously have been
made upon the issuance of such warrants or other rights pursuant to Section
4(e). No further adjustments of the number of shares of Common Stock for which
this Warrant is exercisable and the Warrant Price then in effect shall be made
upon the actual issue of such Common Stock upon conversion or exchange of such
Common Stock Equivalents.

     (g) Superseding Adjustment. If, at any time after any adjustment of the
number of shares of Common Stock for which this Warrant is exercisable and the
Warrant Price then in effect shall have been made pursuant to Section 4(e) or
Section 4(f) as the result of any issuance of warrants, other rights or Common
Stock Equivalents, and (i) such warrants or other rights, or the right of
conversion or exchange in such other Common Stock Equivalents, shall expire, and
all or a portion of such warrants or other rights, or the right of conversion or
exchange with respect to all or a portion of such other Common Stock
Equivalents, as the case may be shall not

                                      -9-

<PAGE>

have been exercised, or (ii) the consideration per share for which shares of
Common Stock are issuable pursuant to such Common Stock Equivalents, shall be
increased solely by virtue of provisions therein contained for an automatic
increase in such consideration per share upon the occurrence of a specified date
or event, then for each outstanding Warrant such previous adjustment shall be
rescinded and annulled and the Additional Shares of Common Stock which were
deemed to have been issued by virtue of the computation made in connection with
the adjustment so rescinded and annulled shall no longer be deemed to have been
issued by virtue of such computation. Upon the occurrence of an event set forth
in this Section 4(g) above, there shall be a recomputation made of the effect of
such Common Stock Equivalents on the basis of: (i) treating the number of
Additional Shares of Common Stock or other property, if any, theretofore
actually issued or issuable pursuant to the previous exercise of any such
warrants or other rights or any such right of conversion or exchange, as having
been issued on the date or dates of any such exercise and for the consideration
actually received and receivable therefor, and (ii) treating any such Common
Stock Equivalents which then remain outstanding as having been granted or issued
immediately after the time of such increase of the consideration per share for
which shares of Common Stock or other property are issuable under such Common
Stock Equivalents; whereupon a new adjustment of the number of shares of Common
Stock for which this Warrant is exercisable and the Warrant Price then in effect
shall be made, which new adjustment shall supersede the previous adjustment so
rescinded and annulled.

     (h) Purchase of Common Stock by the Issuer. If the Issuer at any time while
this Warrant is outstanding shall, directly or indirectly through a Subsidiary
or otherwise, purchase, redeem or otherwise acquire any shares of Common Stock
at a price per share greater than the Per Share Market Value, then the Warrant
Price upon each such purchase, redemption or acquisition shall be adjusted to
that price determined by multiplying such Warrant Price by a fraction (i) the
numerator of which shall be the number of shares of Outstanding Common Stock
immediately prior to such purchase, redemption or acquisition minus the number
of shares of Common Stock which the aggregate consideration for the total number
of such shares of Common Stock so purchased, redeemed or acquired would purchase
at the Per Share Market Value; and (ii) the denominator of which shall be the
number of shares of Outstanding Common Stock immediately after such purchase,
redemption or acquisition. For the purposes of this subsection (h), the date as
of which the Per Share Market Price shall be computed shall be the earlier of
(x) the date on which the Issuer shall enter into a firm contract for the
purchase, redemption or acquisition of such Common Stock, or (y) the date of
actual purchase, redemption or acquisition of such Common Stock. For the
purposes of this subsection (h), a purchase, redemption or acquisition of a
Common Stock Equivalent shall be deemed to be a purchase of the underlying
Common Stock, and the computation herein required shall be made on the basis of
the full exercise, conversion or exchange of such Common Stock Equivalent on the
date as of which such computation is required hereby to be made, whether or not
such Common Stock Equivalent is actually exercisable, convertible or
exchangeable on such date.

     (i) Other Provisions applicable to Adjustments under this Section. The
following provisions shall be applicable to the making of adjustments of the
number of shares of Common Stock for which this Warrant is exercisable and the
Warrant Price then in effect provided for in this Section 4:

                                      -10-

<PAGE>

          (i) Computation of Consideration. To the extent that any Additional
     Shares of Common Stock or any Common Stock Equivalents (or any warrants or
     other rights therefor) shall be issued for cash consideration, the
     consideration received by the Issuer therefor shall be the amount of the
     cash received by the Issuer therefor, or, if such Additional Shares of
     Common Stock or Common Stock Equivalents are offered by the Issuer for
     subscription, the subscription price, or, if such Additional Shares of
     Common Stock or Common Stock Equivalents are sold to underwriters or
     dealers for public offering without a subscription offering, the initial
     public offering price (in any such case subtracting any amounts paid or
     receivable for accrued interest or accrued dividends and without taking
     into account any compensation, discounts or expenses paid or incurred by
     the Issuer for and in the underwriting of, or otherwise in connection with,
     the issuance thereof). To the extent that such issuance shall be for a
     consideration other than cash, then, except as herein otherwise expressly
     provided, the amount of such consideration shall be deemed to be the fair
     value of such consideration at the time of such issuance as determined in
     good faith by the Board of Directors of the Issuer. In case any Additional
     Shares of Common Stock or any Common Stock Equivalents (or any warrants or
     other rights therefor) shall be issued in connection with any merger in
     which the Issuer issues any securities, the amount of consideration
     therefor shall be deemed to be the fair value, as determined in good faith
     by the Board of Directors of the Issuer, of such portion of the assets and
     business of the nonsurviving corporation as such Board in good faith shall
     determine to be attributable to such Additional Shares of Common Stock,
     Common Stock Equivalents, or any warrants or other rights therefor, as the
     case may be. The consideration for any Additional Shares of Common Stock
     issuable pursuant to any warrants or other rights to subscribe for or
     purchase the same shall be the consideration received by the Issuer for
     issuing such warrants or other rights plus the additional consideration
     payable to the Issuer upon exercise of such warrants or other rights. The
     consideration for any Additional Shares of Common Stock issuable pursuant
     to the terms of any Common Stock Equivalents shall be the consideration
     received by the Issuer for issuing warrants or other rights to subscribe
     for or purchase such Common Stock Equivalents, plus the consideration paid
     or payable to the Issuer in respect of the subscription for or purchase of
     such Common Stock Equivalents, plus the additional consideration, if any,
     payable to the Issuer upon the exercise of the right of conversion or
     exchange in such Common Stock Equivalents. In case of the issuance at any
     time of any Additional Shares of Common Stock or Common Stock Equivalents
     in payment or satisfaction of any dividends upon any class of stock other
     than Common Stock, the Issuer shall be deemed to have received for such
     Additional Shares of Common Stock or Common Stock Equivalents a
     consideration equal to the amount of such dividend so paid or satisfied.

          (ii) When Adjustments to Be Made. The adjustments required by this
     Section 4 shall be made whenever and as often as any specified event
     requiring an adjustment shall occur, except that any adjustment of the
     number of shares of Common Stock for which this Warrant is exercisable that
     would otherwise be required may be postponed (except in the case of a
     subdivision or combination of shares of the Common Stock, as provided for
     in Section 4(b)) up to, but not beyond the date of exercise if such
     adjustment either by itself or with other adjustments not previously made
     adds or subtracts less than one percent (1%) of the shares of Common Stock
     for which this Warrant is exercisable immediately prior to the making of
     such

                                      -11-

<PAGE>

     adjustment. Any adjustment representing a change of less than such minimum
     amount (except as aforesaid) which is postponed shall be carried forward
     and made as soon as such adjustment, together with other adjustments
     required by this Section 4 and not previously made, would result in a
     minimum adjustment or on the date of exercise. For the purpose of any
     adjustment, any specified event shall be deemed to have occurred at the
     close of business on the date of its occurrence.

          (iii) Fractional Interests. In computing adjustments under this
     Section 4, fractional interests in Common Stock shall be taken into account
     to the nearest one one-hundredth (1/100th) of a share.

          (iv) When Adjustment Not Required. If the Issuer shall take a record
     of the holders of its Common Stock for the purpose of entitling them to
     receive a dividend or distribution or subscription or purchase rights and
     shall, thereafter and before the distribution to stockholders thereof,
     legally abandon its plan to pay or deliver such dividend, distribution,
     subscription or purchase rights, then thereafter no adjustment shall be
     required by reason of the taking of such record and any such adjustment
     previously made in respect thereof shall be rescinded and annulled.

     (j) Form of Warrant after Adjustments. The form of this Warrant need not be
changed because of any adjustments in the Warrant Price or the number and kind
of Securities purchasable upon the exercise of this Warrant.

     (k) Escrow of Warrant Stock. If after any property becomes distributable
pursuant to this Section 4 by reason of the taking of any record of the holders
of Common Stock, but prior to the occurrence of the event for which such record
is taken, and the Holder exercises this Warrant, any shares of Common Stock
issuable upon exercise by reason of such adjustment shall be deemed the last
shares of Common Stock for which this Warrant is exercised (notwithstanding any
other provision to the contrary herein) and such shares or other property shall
be held in escrow for the Holder by the Issuer to be issued to the Holder upon
and to the extent that the event actually takes place, upon payment of the
current Warrant Price. Notwithstanding any other provision to the contrary
herein, if the event for which such record was taken fails to occur or is
rescinded, then such escrowed shares shall be cancelled by the Issuer and
escrowed property returned.

     5. Notice of Adjustments. Whenever the Warrant Price or Warrant Share
Number shall be adjusted pursuant to Section 4 hereof (for purposes of this
Section 5, each an "adjustment"), the Issuer shall cause its Chief Financial
Officer to prepare and execute a certificate setting forth, in reasonable
detail, the event requiring the adjustment, the amount of the adjustment, the
method by which such adjustment was calculated (including a description of the
basis on which the Board made any determination hereunder), and the Warrant
Price and Warrant Share Number after giving effect to such adjustment, and shall
cause copies of such certificate to be delivered to the Holder of this Warrant
promptly after each adjustment. Any dispute between the Issuer and the Holder of
this Warrant with respect to the matters set forth in such certificate may at
the option of the Holder of this Warrant be submitted to one of the

                                      -12-

<PAGE>

national accounting firms currently known as the "big five" selected by the
Holder, provided that the Issuer shall have ten (10) days after receipt of
notice from such Holder of its selection of such firm to object thereto, in
which case such Holder shall select another such firm and the Issuer shall have
no such right of objection. The firm selected by the Holder of this Warrant as
provided in the preceding sentence shall be instructed to deliver a written
opinion as to such matters to the Issuer and such Holder within thirty (30) days
after submission to it of such dispute. Such opinion shall be final and binding
on the parties hereto.

     6. Fractional Shares. No fractional shares of Warrant Stock will be issued
in connection with and exercise hereof, but in lieu of such fractional shares,
the Issuer shall make a cash payment therefor equal in amount to the product of
the applicable fraction multiplied by the Per Share Market Value then in effect.

     7. Ownership Cap and Certain Exercise Restrictions. (a) Notwithstanding
anything to the contrary set forth in this Warrant, at no time may a Holder of
this Warrant exercise this Warrant if the number of shares of Common Stock to be
issued pursuant to such exercise would exceed, when aggregated with all other
shares of Common Stock owned by such Holder at such time, the number of shares
of Common Stock which would result in such Holder owning more than 4.999% of all
of the Common Stock outstanding at such time; provided, however, that upon a
holder of this Warrant providing the Issuer with sixty-one (61) days notice
(pursuant to Section 12 hereof) (the "Waiver Notice") that such Holder would
like to waive this Section 7(a) with regard to any or all shares of Common Stock
issuable upon exercise of this Warrant, this Section 7(a) will be of no force or
effect with regard to all or a portion of the Warrant referenced in the Waiver
Notice; provided, further, that this provision shall be of no further force or
effect during the sixty-one (61) days immediately preceding the expiration of
the term of this Warrant.

     (b) The Holder may not exercise the Warrant hereunder to the extent such
exercise would result in the Holder beneficially owning (as determined in
accordance with Section 13(d) of the Exchange Act and the rules thereunder) in
excess of 9.999% of the then issued and outstanding shares of Common Stock,
including shares issuable upon exercise of the Warrant held by the Holder after
application of this Section; provided, however, that upon a holder of this
Warrant providing the Company with a Waiver Notice that such holder would like
to waive this Section 7(b) with regard to any or all shares of Common Stock
issuable upon exercise of this Warrant, this Section 7(b) shall be of no force
or effect with regard to those shares of Warrant Stock referenced in the Waiver
Notice; provided, further, that this provision shall be of no further force or
effect during the sixty-one (61) days immediately preceding the expiration of
the term of this Warrant.

     8. Definitions. For the purposes of this Warrant, the following terms have
the following meanings:

          "Additional Shares of Common Stock" means all shares of Common Stock
     issued by the Issuer after the Original Issue Date, and all shares of Other
     Common, if any, issued by the Issuer after the Original Issue Date, except:
     (1) shares of Common Stock to be issued to strategic partners and/or in
     connection with a strategic merger or acquisition;

                                      -13-

<PAGE>

     (2) shares of Common Stock or the issuance of options to purchase shares of
     Common Stock to employees, officers, directors, consultants and vendors in
     accordance with the Issuer's equity incentive policies; (3) the issuance of
     securities pursuant to an underwritten public offering of the Issuer's
     securities; (4) the conversion or exercise of convertible or exercisable
     securities issued or outstanding on or prior to the date hereof; (5) the
     Warrant Stock; (6) any registered exchange offer to be effected by the
     Issuer to holders of all of its warrants outstanding prior to the Original
     Issue Date, as described in the Lender Common Stock Purchase Agreement; (7)
     the issuance of securities pursuant to the Lender Common Stock Purchase
     Agreement; and (8) the issuance of securities pursuant to the Exchange
     Agreements.

          "Board" shall mean the Board of Directors of the Issuer.

          "Capital Stock" means and includes (i) any and all shares, interests,
     participations or other equivalents of or interests in (however designated)
     corporate stock, including, without limitation, shares of preferred or
     preference stock, (ii) all partnership interests (whether general or
     limited) in any Person which is a partnership, (iii) all membership
     interests or limited liability company interests in any limited liability
     company, and (iv) all equity or ownership interests in any Person of any
     other type.

          "Certificate of Incorporation" means the Certificate of Incorporation
     of the Issuer as in effect on the Original Issue Date, and as hereafter
     from time to time amended, modified, supplemented or restated in accordance
     with the terms hereof and thereof and pursuant to applicable law.

          "Common Stock" means the Common Stock, par value $.001 per share, of
     the Issuer and any other Capital Stock into which such stock may hereafter
     be changed.

          "Common Stock Equivalent" means any Convertible Security or warrant,
     option or other right to subscribe for or purchase any Additional Shares of
     Common Stock or any Convertible Security.

          "Convertible Securities" means evidences of Indebtedness, shares of
     Capital Stock or other Securities which are or may be at any time
     convertible into or exchangeable for Additional Shares of Common Stock. The
     term "Convertible Security" means one of the Convertible Securities.

          "Exchange Agreements" means, collectively, (1) the Note Exchange
     Agreement dated as of October 30, 2002, by and between the Issuer and SDS
     Merchant Fund, L.P. ("SDS") (in connection with the surrender by SDS of the
     promissory note issued December 7, 2001 by the Issuer to Nortel Networks,
     Inc.); (2) the Share Exchange Agreement, dated as of October 30, 2002, by
     and among the Issuer and each of the purchasers whose names appear on the
     signature pages thereto (which agreement provides for the issuance of
     Common Stock upon surrender of shares of the Issuer's Series H preferred
     stock); (3) the Series J-1 Exchange Agreement dated as of October 30,

                                      -14-

<PAGE>

     2002, by and among the Issuer and the holders of the Issuer's Series J-1
     preferred stock; (4) the Common Stock and Warrant Purchase Agreement dated
     as of October 30, 2002 by and among the Issuer and the lenders under the
     Issuer's senior credit facility; (5) any agreement entered into after the
     date hereof between SDS and the Issuer providing for the surrender by SDS
     to the Issuer of that certain promissory note issued by the Issuer to SDS
     in March 2002 in an initial principal amount of $2,000,000; and (6) any
     related agreement or amendment to the Common Stock and Warrant Purchase
     Agreement referred to in clause (4) of this definition providing for the
     issuance of additional shares of Common Stock and/or warrants to the
     lenders under the Issuer's senior credit facility in connection with the
     conversion of additional indebtedness or interest accrued thereon under
     such credit facility.

          "Governmental Authority" means any governmental, regulatory or
     self-regulatory entity, department, body, official, authority, commission,
     board, agency or instrumentality, whether federal, state or local, and
     whether domestic or foreign.

          "Holders" mean the Persons who shall from time to time own any
     Warrant. The term "Holder" means one of the Holders.

          "Independent Appraiser" means a nationally recognized or major
     regional investment banking firm or firm of independent certified public
     accountants of recognized standing (which may be the firm that regularly
     examines the financial statements of the Issuer) that is regularly engaged
     in the business of appraising the Capital Stock or assets of corporations
     or other entities as going concerns, and which is not affiliated with
     either the Issuer or the Holder of any Warrant.

          "Issuer" means FiberNet Telecom Group, Inc., a Delaware corporation,
     and its successors.

          "Lender Common Stock Purchase Agreement" shall mean that certain
     Common Stock Purchase Agreement dated as of October 30, 2002, by and among
     the Company and the lenders under the Company's senior credit facility.

          "Majority Holders" means at any time the Holders of Warrants
     exercisable for a majority of the shares of Warrant Stock issuable under
     the Warrants at the time outstanding.

          "Nasdaq" means the Nasdaq SmallCap Market.

          "Original Issue Date" means October 30, 2002.

          "OTC Bulletin Board" means the over-the-counter electronic bulletin
     board.

          "Other Common" means any other Capital Stock of the Issuer of any
     class which shall be authorized at any time after the date of this Warrant
     (other than Common Stock)

                                      -15-

<PAGE>

     and which shall have the right to participate in the distribution of
     earnings and assets of the Issuer without limitation as to amount.

          "Outstanding Common Stock" means, at any given time, the aggregate
     amount of outstanding shares of Common Stock, assuming full exercise,
     conversion or exchange (as applicable) of all options, warrants and other
     Securities which are convertible into or exercisable or exchangeable for,
     and any right to subscribe for, shares of Common Stock that are outstanding
     at such time.

          "Person" means an individual, corporation, limited liability company,
     partnership, joint stock company, trust, unincorporated organization, joint
     venture, Governmental Authority or other entity of whatever nature.

          "Per Share Market Value" means on any particular date (a) the closing
     bid price per share of the Common Stock on such date on Nasdaq or another
     registered national stock exchange on which the Common Stock is then
     listed, or if there is no such price on such date, then the closing bid
     price on such exchange or quotation system on the date nearest preceding
     such date, or (b) if the Common Stock is not listed then on Nasdaq or any
     registered national stock exchange, the closing bid price for a share of
     Common Stock in the over-the-counter market, as reported by the OTC
     Bulletin Board or in the National Quotation Bureau Incorporated or similar
     organization or agency succeeding to its functions of reporting prices) at
     the close of business on such date, or (c) if the Common Stock is not then
     reported by the OTC Bulletin Board or the National Quotation Bureau
     Incorporated (or similar organization or agency succeeding to its functions
     of reporting prices), then the average of the "Pink Sheet" quotes for the
     relevant conversion period, as determined in good faith by the holder, or
     (d) if the Common Stock is not then publicly traded the fair market value
     of a share of Common Stock as determined by an Independent Appraiser
     selected in good faith by the Majority Holders; provided, however, that the
     Issuer, after receipt of the determination by such Independent Appraiser,
     shall have the right to select an additional Independent Appraiser, in
     which case, the fair market value shall be equal to the average of the
     determinations by each such Independent Appraiser; and provided, further
     that all determinations of the Per Share Market Value shall be
     appropriately adjusted for any stock dividends, stock splits or other
     similar transactions during such period. The determination of fair market
     value by an Independent Appraiser shall be based upon the fair market value
     of the Issuer determined on a going concern basis as between a willing
     buyer and a willing seller and taking into account all relevant factors
     determinative of value, and shall be final and binding on all parties. In
     determining the fair market value of any shares of Common Stock, no
     consideration shall be given to any restrictions on transfer of the Common
     Stock imposed by agreement or by federal or state securities laws, or to
     the existence or absence of, or any limitations on, voting rights.

          "Purchase Agreement" means the Common Stock Purchase Agreement dated
     as of October 30, 2002, among the Issuer and the investors a party thereto.

                                      -16-

<PAGE>

          "Securities" means any debt or equity securities of the Issuer,
     whether now or hereafter authorized, any instrument convertible into or
     exchangeable for Securities or a Security, and any option, warrant or other
     right to purchase or acquire any Security. "Security" means one of the
     Securities.

          "Securities Act" means the Securities Act of 1933, as amended, or any
     similar federal statute then in effect.

          "Subsidiary" means any corporation at least 50% of whose outstanding
     Voting Stock shall at the time be owned directly or indirectly by the
     Issuer or by one or more of its Subsidiaries, or by the Issuer and one or
     more of its Subsidiaries.

          "Term" has the meaning specified in Section 1 hereof.

          "Trading Day" means (a) a day on which the Common Stock is traded on
     Nasdaq, or (b) if the Common Stock is not listed on Nasdaq, a day on which
     the Common Stock is traded on any other registered national stock exchange,
     or (c) if the Common Stock is not traded on any other registered national
     stock exchange, a day on which the Common Stock is traded on the OTC
     Bulletin Board, or (d) if the Common Stock is not traded on the OTC
     Bulletin Board, a day on which the Common Stock is quoted in the
     over-the-counter market as reported by the National Quotation Bureau
     Incorporated (or any similar organization or agency succeeding its
     functions of reporting prices); provided, however, that in the event that
     the Common Stock is not listed or quoted as set forth in (a), (b) and (c)
     hereof, then Trading Day shall mean any day except Saturday, Sunday and any
     day which shall be a legal holiday or a day on which banking institutions
     in the State of New York are authorized or required by law or other
     government action to close.

          "Voting Stock" means, as applied to the Capital Stock of any
     corporation, Capital Stock of any class or classes (however designated)
     having ordinary voting power for the election of a majority of the members
     of the Board of Directors (or other governing body) of such corporation,
     other than Capital Stock having such power only by reason of the happening
     of a contingency.

          "Warrants" means the Warrants issued and sold pursuant to the Purchase
     Agreement, including, without limitation, this Warrant, and any other
     warrants of like tenor issued in substitution or exchange for any thereof
     pursuant to the provisions of Section 2(c), 2(d) or 2(e) hereof or of any
     of such other Warrants.

          "Warrant Price" initially means U.S. $.12, as such price may be
     adjusted from time to time as shall result from the adjustments specified
     in this Warrant, including Section 4 hereto.

          "Warrant Share Number" means at any time the aggregate number of
     shares of Warrant Stock which may at such time be purchased upon exercise
     of this Warrant, after

                                      -17-

<PAGE>

     giving effect to all prior adjustments and increases to such number made or
     required to be made under the terms hereof.

          "Warrant Stock" means Common Stock issuable upon exercise of any
     Warrant or Warrants or otherwise issuable pursuant to any Warrant or
     Warrants.

     9. Other Notices. In case at any time:

          (A)  the Issuer shall make any distributions to the holders of Common
               Stock; or

          (B)  the Issuer shall authorize the granting to all holders of its
               Common Stock of rights to subscribe for or purchase any shares of
               Capital Stock of any class or other rights; or

          (C)  there shall be any reclassification of the Capital Stock of the
               Issuer; or

          (D)  there shall be any capital reorganization by the Issuer; or

          (E)  there shall be any (i) consolidation or merger involving the
               Issuer or (ii) sale, transfer or other disposition of all or
               substantially all of the Issuer's property, assets or business
               (except a merger or other reorganization in which the Issuer
               shall be the surviving corporation and its shares of Capital
               Stock shall continue to be outstanding and unchanged and except a
               consolidation, merger, sale, transfer or other disposition
               involving a wholly-owned Subsidiary); or

          (F)  there shall be a voluntary or involuntary dissolution,
               liquidation or winding-up of the Issuer or any partial
               liquidation of the Issuer or distribution to holders of Common
               Stock;

then, in each of such cases, the Issuer shall give written notice to the Holder
of the date on which (i) the books of the Issuer shall close or a record shall
be taken for such dividend, distribution or subscription rights or (ii) such
reorganization, reclassification, consolidation, merger, disposition,
dissolution, liquidation or winding-up, as the case may be, shall take place.
Such notice also shall specify the date as of which the holders of Common Stock
of record shall participate in such dividend, distribution or subscription
rights, or shall be entitled to exchange their certificates for Common Stock for
securities or other property deliverable upon such reorganization,
reclassification, consolidation, merger, disposition, dissolution, liquidation
or winding-up, as the case may be. Such notice shall be given at least twenty
(20) days prior to the action in question and not less than ten (10) days prior
to the record date or the date on which the Issuer's transfer books are closed
in respect thereto. This Warrant entitles the Holder to receive

                                      -18-

<PAGE>

copies of all financial and other information distributed or required to be
distributed to the holders of the Common Stock.

     10. Amendment and Waiver. Any term, covenant, agreement or condition in
this Warrant may be amended, or compliance therewith may be waived (either
generally or in a particular instance and either retroactively or
prospectively), by a written instrument or written instruments executed by the
Issuer and the Majority Holders; provided, however, that no such amendment or
waiver shall reduce the Warrant Share Number, increase the Warrant Price,
shorten the period during which this Warrant may be exercised or modify any
provision of this Section 10 without the consent of the Holder of this Warrant.

     11. Governing Law. THIS WARRANT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT GIVING EFFECT TO
PRINCIPLES OF CONFLICTS OF LAW.

     12. Notices. Any and all notices or other communications or deliveries
required or permitted to be provided hereunder shall be in writing and shall be
deemed given and effective on the earlier of (i) the date of transmission, if
such notice or communication is delivered via facsimile at the facsimile
telephone number specified for notice prior to 5:00 p.m., eastern time, on a
Trading Day, (ii) the Trading Day after the date of transmission, if such notice
or communication is delivered via facsimile at the facsimile telephone number
specified for notice later than 5:00 p.m., eastern time, on any date and earlier
than 11:59 p.m., eastern time, on such date, (iii) the Trading Day following the
date of mailing, if sent by nationally recognized overnight courier service or
(iv) actual receipt by the party to whom such notice is required to be given.
The addresses for such communications shall be with respect to the Holder of
this Warrant or of Warrant Stock issued pursuant hereto, addressed to such
Holder at its last known address or facsimile number appearing on the books of
the Issuer maintained for such purposes, or with respect to the Issuer,
addressed to:

                        FiberNet Telecom Group, Inc.
                        570 Lexington Avenue
                        New York, New York 10022
                        Attention: President
                        Tel. No.: (212) 405-6200
                        Fax No.:  (212) 421-8860

Copies of notices to the Holder shall be sent to Jenkens & Gilchrist Parker
Chapin LLP, 405 Lexington Avenue, New York, New York 10174, Attention:
Christopher S. Auguste, Esq., Facsimile No.: (212) 704-6288. Any party hereto
may from time to time change its address for notices by giving at least ten (10)
days written notice of such changed address to the other party hereto.

     13. Warrant Agent. The Issuer may, by written notice to each Holder of this
Warrant, appoint an agent having an office in New York, New York for the purpose
of issuing shares of Warrant Stock on the exercise of this Warrant pursuant to
subsection (b) of Section 2 hereof,

                                      -19-

<PAGE>

exchanging this Warrant pursuant to subsection (d) of Section 2 hereof or
replacing this Warrant pursuant to subsection (d) of Section 3 hereof, or any of
the foregoing, and thereafter any such issuance, exchange or replacement, as the
case may be, shall be made at such office by such agent.

     14. Remedies. The Issuer stipulates that the remedies at law of the Holder
of this Warrant in the event of any default or threatened default by the Issuer
in the performance of or compliance with any of the terms of this Warrant are
not and will not be adequate and that, to the fullest extent permitted by law,
such terms may be specifically enforced by a decree for the specific performance
of any agreement contained herein or by an injunction against a violation of any
of the terms hereof or otherwise.

     15. Successors and Assigns. This Warrant and the rights evidenced hereby
shall inure to the benefit of and be binding upon the successors and assigns of
the Issuer, the Holder hereof and (to the extent provided herein) the Holders of
Warrant Stock issued pursuant hereto, and shall be enforceable by any such
Holder or Holder of Warrant Stock.

     16. Modification and Severability. If, in any action before any court or
agency legally empowered to enforce any provision contained herein, any
provision hereof is found to be unenforceable, then such provision shall be
deemed modified to the extent necessary to make it enforceable by such court or
agency. If any such provision is not enforceable as set forth in the preceding
sentence, the unenforceability of such provision shall not affect the other
provisions of this Warrant, but this Warrant shall be construed as if such
unenforceable provision had never been contained herein.

     17. Headings. The headings of the Sections of this Warrant are for
convenience of reference only and shall not, for any purpose, be deemed a part
of this Warrant.

                                      -20-

<PAGE>

     IN WITNESS WHEREOF, the Issuer has executed this Warrant as of the day and
year first above written.

                                        FIBERNET TELECOM GROUP, INC.

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

                                      -21-

<PAGE>

                                  EXERCISE FORM

                          FIBERNET TELECOM GROUP, INC.

The undersigned _______________, pursuant to the provisions of the within
Warrant, hereby elects to purchase _____ shares of Common Stock of FiberNet
Telecom Group, Inc. covered by the within Warrant.

Dated: _________________                Signature   ___________________________

                                        Address     ___________________________
                                                    ___________________________

                                   ASSIGNMENT

FOR VALUE RECEIVED, _________________ hereby sells, assigns and transfers unto
__________________ the within Warrant and all rights evidenced thereby and does
irrevocably constitute and appoint _____________, attorney, to transfer the said
Warrant on the books of the within named corporation.

Dated: _________________                Signature   ___________________________

                                        Address     ___________________________
                                                    ___________________________

                               PARTIAL ASSIGNMENT

FOR VALUE RECEIVED, _________________ hereby sells, assigns and transfers unto
__________________ the right to purchase _________ shares of Warrant Stock
evidenced by the within Warrant together with all rights therein, and does
irrevocably constitute and appoint ___________________, attorney, to transfer
that part of the said Warrant on the books of the within named corporation.

Dated: _________________                Signature   ___________________________

                                        Address     ___________________________
                                                    ___________________________

                           FOR USE BY THE ISSUER ONLY:

This Warrant No. W-___ canceled (or transferred or exchanged) this _____ day of
___________, _____, shares of Common Stock issued therefor in the name of
_______________, Warrant No. W-_____ issued for ____ shares of Common Stock in
the name of _______________.

                                      -22-

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00044-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00044-of-00352.parquet"}]]