<PAGE>

                                                                    Exhibit 4.10



                              GLOBAL CROSSING LTD.

                                      and

                        _______________________________
                               Debt Warrant Agent



                               _________________

                [SENIOR] [SUBORDINATED] DEBT WARRANT AGREEMENT*


                           Dated as of ______________

                                ________________


-------------------------------------------------------------------------------
*    OPTIONS REPRESENTED BY BRACKETED OR BLANK SECTIONS HEREIN  SHALL BE
     DETERMINED IN CONFORMITY WITH THE APPLICABLE PROSPECTUS SUPPLEMENT OR
     SUPPLEMENTS.
<PAGE>

                            TABLE OF CONTENTS **



                                                                            Page
                                                                            ----

PARTIES ...................................................................   1
RECITALS ..................................................................   1

ARTICLE I  ISSUANCE OF DEBT WARRANTS AND EXECUTION AND DELIVERYOF DEBT
           WARRANT CERTIFICATES............................................  -1-
   Section 1.01.  Issuance of Debt Warrants................................  -1-
   Section 1.02  Form and Execution of Debt Warrant Certificates...........  -2-
   Section 1.03  Issuance and Delivery of Debt Warrant Certificates........  -3-
   Section 1.04  Temporary Debt Warrant Certificates.......................  -3-
   Section 1.05  Payment of Certain Taxes..................................  -3-
   Section 1.06  "Holder"..................................................  -4-

ARTICLE II  DURATION AND EXERCISE OF DEBT WARRANTS.........................  -4-
   Section 2.01  Duration of Debt Warrants.................................  -4-
   Section 2.02  Exercise of Debt Warrants.................................  -4-

ARTICLE III  OTHER PROVISIONS RELATING TO RIGHTS OF HOLDERSOF DEBT
             WARRANTS......................................................  -5-
   Section 3.01  No Rights as Holder of Underlying Debt Securities
                 Conferred by Debt Warrants or Debt Warrant Certificates...  -5-
   Section 3.02  Lost, Stolen, Destroyed or Mutilated Debt Warrant
                 Certificates..............................................  -5-
   Section 3.03  Holder of Debt Warrants May Enforce Rights................  -6-

ARTICLE IV  EXCHANGE AND TRANSFER OF DEBT WARRANTS.........................  -6-
   Section 4.01  Debt Warrant Register; Exchange and Transfer of Debt
                 Warrants..................................................  -6-
   Section 4.02  Treatment of Holders of Debt Warrants Certificates........  -7-
   Section 4.03  Cancellation of Debt Warrant Certificates.................  -7-

ARTICLE V  CONCERNING THE DEBT WARRANT AGENT...............................  -8-
   Section 5.01  Debt Warrant Agent........................................  -8-
   Section 5.02  Conditions of Debt Warrant Agent's Obligations............  -8-
   Section 5.03  Resignation and Removal; Appointment of Successor......... -10-
   Section 5.04  Compliance With Applicable Laws........................... -12-
   Section 5.05  Office.................................................... -12-

-----------------
**  The Table of Contents is not part of the Debt Warrant Agreement.

                                       ii
<PAGE>

ARTICLE VI  MISCELLANEOUS.................................................  -12-
   Section 6.01  Consolidation, Merger or Amalgamation of the Company
                 and Conveyance or Transfer Permitted Subject to
                 Certain Conditions.......................................  -12-
   Section 6.02  Rights and Duties of Successor Corporation...............  -12-
   Section 6.03  Supplements and Amendments...............................  -13-
   Section 6.04  Notices and Demands to the Company and Debt Warrant
                 Agent....................................................  -13-
   Section 6.05  Addresses................................................  -13-
   Section 6.06  Applicable Law...........................................  -13-
   Section 6.07  Delivery of Prospectus...................................  -14-
   Section 6.08  Governmental Approvals...................................  -14-
   Section 6.09  Persons Having Rights under Debt Warrant Agreement.......  -14-
   Section 6.10  Headings.................................................  -14-
   Section 6.11  Counterparts.............................................  -14-
   Section 6.12  Consent to Jurisdiction and Service......................  -15-
   Section 6.13  Inspection of Agreement..................................  -16-

                                      iii
<PAGE>

     THIS [SENIOR] [SUBORDINATED] DEBT WARRANT AGREEMENT, dated  as of
__________, between Global Crossing Ltd., a Bermuda company (the "Company"), and
____________________, a __________ organized and existing under the laws of
__________, as warrant agent (the "Debt Warrant Agent").

     WHEREAS, the Company and _____________________ has entered into an
Indenture dated as of [               ] (the "Indenture") with United States
Trust Company of New York, as trustee (the "Trustee"), providing for the
issuance by the Company from time to time, in one or more series, of debt
securities evidencing its unsecured, ________________ indebtedness (such debt
securities, being referred to as the "Securities");

     WHEREAS, the Company proposes to issue warrants (the "Debt Warrants")
representing the right to purchase Debt Securities of one or more series (the
"Underlying Debt Securities");

     WHEREAS, the Company has duly authorized the execution and delivery of this
Debt Warrant Agreement to provide for the issuance of Debt Warrants to be
exercisable at such times and for such prices, and to have such other
provisions, as shall be fixed as hereinafter provided; and

     WHEREAS, the Company desires the Debt Warrant Agent to Act on behalf of the
Company, and the Debt Warrant Agent is willing to act in connection with the
issuance of the Debt Warrant Certificates and other matters as provided below.

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

                                   ARTICLE I
              ISSUANCE OF DEBT WARRANTS AND EXECUTION AND DELIVERY
                          OF DEBT WARRANT CERTIFICATES

     Section 1.01.  Issuance of Debt Warrants.  Debt Warrants may be issued from
                    -------------------------
time to time.  Prior to the issuance of any Debt Warrants, there shall be
established by or pursuant to a resolution or resolutions duly adopted by the
Company's Board of Directors or by any committee thereof duly authorized to act
with respect thereto (a "Board Resolution"):

          a)   the title and aggregate number of such Debt Warrants;

          b)   the offering price of such Debt Warrants, if any;

          c)  the title, aggregate principal amount, ranking and terms
(including the subordination and conversion provisions) of the Underlying Debt
Securities that may be purchased upon exercise of such Debt Warrants;

                                      -1-
<PAGE>

          d)  the time or times at which, or period or periods during which,
such Debt Warrants may be exercised, the minimum or maximum amount of Debt
Warrants which may be exercised at any one time and the final date on which such
Debt Warrants may be exercised (the "Expiration Date");

          e)  the principal amount of Underlying Debt Securities that may be
purchased upon exercise of each Debt Warrant and the price, or the manner of
determining the price (the "Debt Warrant Price"), at which such principal amount
may be purchased upon such exercise;

          f)  the terms of any right to redeem or call such Debt Warrants; and

          g)  any other terms of such Debt Warrants not inconsistent with the
provisions of this Agreement.

     Section 1.02  Form and Execution of Debt Warrant Certificates.
                   -----------------------------------------------

          a)  The Debt Warrants shall be evidenced by warrant certificates (the
"Debt Warrant Certificates"), which may be in registered or bearer form and
otherwise shall be substantially in such form or forms as shall be established
by or pursuant to a Board Resolution.  Each Debt Warrant Certificate, whenever
issued, shall be dated the date it is countersigned by the Debt Warrant Agent
and may have such letters, numbers or other identifying marks and such legends
or endorsements printed, lithographed or engraved thereon as are not
inconsistent with the provisions of this Agreement, or as may be required to
comply with any applicable law, rule or regulation or with any rule or
regulation of any securities exchange on which the Debt Warrants may be listed,
or to conform to usage, as the officer of the Company executing the same may
approve (such officer's execution thereof to be conclusive evidence of such
approval).  Each Debt Warrant Certificate shall evidence one or more Debt
Warrants.

          b)  The Debt Warrant Certificates shall be signed in the name and on
behalf of the Company by its Chairman of the Board of Directors, its President,
an Executive Vice President, any Vice President, the Treasurer or any Assistant
Treasurer and by its Secretary or any Assistant Secretary.  Such signatures may
be manual or facsimile signatures of the present or any future holder of any
such office and may be imprinted or otherwise reproduced on the Debt Warrant
Certificates, subject to the Company=s Bye-Laws as in effect from time to time.
The seal of the Company may be in the form of a  facsimile thereof and may be
impressed, affixed, imprinted or otherwise reproduced on the Debt Warrant
Certificates.

          c)  No Debt Warrant Certificate shall be valid for any purpose, and no
Debt Warrant evidenced thereby shall be deemed issued or exercisable, until such
Debt Warrant Certificate has been countersigned by the manual or facsimile
signature of the Debt Warrant Agent.  Such signature by the Debt Warrant Agent
upon any Debt Warrant Certificate executed by the Company shall be conclusive
evidence that the Debt Warrant Certificate so countersigned has been duly issued
hereunder.

                                      -2-
<PAGE>

          d)  In case any officer of the Company who shall have signed any Debt
Warrant Certificate either manually or by facsimile signature shall cease to be
such officer before the Debt Warrant Certificate so signed shall have been
countersigned and delivered by the Debt Warrant Agent, such Debt Warrant
Certificate nevertheless may be countersigned and delivered as though the person
who signed such Debt Warrant Certificate had not ceased to be such officer of
the Company; and any Debt Warrant Certificate may be signed on behalf of the
Company by such person as, at the actual date of the execution of such Debt
Warrant Certificate, shall be the proper officer of the Company, although at the
date of the execution of this Agreement such person was not such an officer.

     Section 1.03  Issuance and Delivery of Debt Warrant Certificates.  At any
                   --------------------------------------------------
time and from time to time after the execution and delivery of this Agreement,
the Company may deliver Debt Warrant Certificates executed by the Company to the
Debt Warrant Agent for countersignature.  Except as provided in the following
sentence, the Debt Warrant Agent shall countersign thereupon and deliver such
Debt Warrant Certificates to or upon the written request of the Company.
Subsequent to the original issuance of a Debt Warrant Certificate evidencing
Debt Warrants, the Debt Warrant Agent shall countersign a new Debt Warrant
Certificate evidencing such Debt Warrants only if such Debt Warrant Certificate
is issued in exchange or substitution for one or more previously countersigned
Debt Warrant Certificates evidencing such Debt Warrants or in connection with
their transfer, as hereinafter provided.

     Section 1.04  Temporary Debt Warrant Certificates.  Pending the preparation
                   -----------------------------------
of definitive Debt Warrant Certificates, the Company may execute, and upon the
order of the Company the Debt Warrant Agent shall countersign and deliver,
temporary Debt Warrant Certificates that are printed, lithographed, typewritten,
mimeographed or otherwise produced, substantially of the tenor of the definitive
Debt Warrant Certificates in lieu of which they are issued and with such
appropriate insertions, omissions, substitutions and other variations as the
officer executing such Debt Warrant Certificates may determine, as evidenced by
such officer's execution of such Debt Warrant Certificates.

          If temporary Debt Warrant Certificates are issued, the Company will
cause definitive Debt Warrant Certificates to be prepared without unreasonable
delay.  After the preparation of definitive Debt Warrant Certificates, the
temporary Debt Warrant Certificates shall be exchangeable for definitive Debt
Warrant Certificates upon surrender of the temporary Debt Warrant Certificates
at the corporate trust office of the Debt Warrant Agent or __________, without
charge to the Holder, as defined in Section 1.06 hereof.  Upon surrender for
cancellation of any one or more temporary Debt Warrant Certificates, the Company
shall execute and the Debt Warrant Agent shall countersign and deliver in
exchange therefor definitive Debt Warrant Certificates representing the same
aggregate number of Debt Warrants.  Until so exchanged, the temporary Debt
Warrant Certificates shall in all respects be entitled to the same benefits
under this Agreement as definitive Debt Warrant Certificates.

                                      -3-
<PAGE>

     Section 1.05  Payment of Certain Taxes.  The Company will pay all stamp and
                   ------------------------
other duties, if any, to which this Agreement or the original issuance of the
Debt Warrants or Debt Warrant Certificates may be subject under the laws of the
United States of America or any state or locality.

     Section 1.06  "Holder".  The term "Holder" or "Holders", as used herein
                    ------
with reference to a Debt Warrant Certificate, shall mean [if registered Debt
Warrants the person or persons in whose name such Debt Warrant Certificate shall
then be registered as set forth in the Debt Warrant Register to be maintained by
the Debt Warrant Agent pursuant to Section 4.01 for that purpose] [if bearer
Debt Warrants - the bearer of such Debt Warrant Certificate].

                                   ARTICLE II
                     DURATION AND EXERCISE OF DEBT WARRANTS

     Section 2.01  Duration of Debt Warrants.  Each Debt Warrant may be
                   -------------------------
exercised at the time or times, or during the period or periods, provided by or
pursuant to the Board Resolution relating thereto and specified in the Debt
Warrant Certificate evidencing such Debt Warrant.  Each Debt Warrant not
exercised at or before 5:00 P.M., New York City time, on its Expiration Date
shall become void, and all rights of the Holder of such Debt Warrant thereunder
and under this Agreement shall cease, provided that the Company reserves the
right to, and may, in its sole discretion, at any time and from time to time, at
such time or times as the Company so determines, extend the Expiration Date of
the Warrants for such periods of time as it chooses.  Whenever the Expiration
Date of the Debt Warrants is so extended, the Company shall at least [20] days
prior to the then Expiration Date cause to be mailed to the Debt Warrant Agent
and the registered Holders of the Debt Warrants in accordance with the
provisions of Section 6.04 hereof a notice stating that the Expiration Date has
been extended and setting forth the new Expiration  Date.

     Section 2.02  Exercise of Debt Warrants.  a)  The Holder of a Debt Warrant
                   -------------------------
shall have the right, at its option, to exercise such Debt Warrant and, subject
to subsection (f) of this Section 2.02, purchase the principal amount of
Underlying Debt Securities provided for therein at the time or times or during
the period or periods referred to in Section 2.01 and specified in the Debt
Warrant Certificate evidencing such Debt Warrant.  Except as may be provided in
a Debt Warrant Certificate, a Debt Warrant may be exercised by completing the
form of election to purchase set forth on the reverse side of the Debt Warrant
Certificate, by duly executing and delivering the same, together with payment in
full of the Debt Warrant Price in lawful money of the United States of America,
in cash or by certified or official bank check or by bank wire transfer, to the
Debt Warrant Agent.  Except as may be provided in a Debt Warrant Certificate,
the date on which such Debt Warrant Certificate and payment are received by the
Debt Warrant Agent as aforesaid shall be deemed to be the date on which the Debt
Warrant is exercised and the Underlying Debt Securities are issued.

                                      -4-
<PAGE>

          b)  Upon the exercise of a Debt Warrant, the Company shall issue,
pursuant to the Indenture, in authorized denominations to or upon the order of
the Holder of such Debt Warrant, the Underlying Debt Securities to which such
Holder is entitled, in the form required under such Indenture, registered, in
the case of Underlying Debt Securities in registered form, in such name or names
as may be directed by such Holder.

          c)  If fewer than all of the Debt Warrants evidenced by a Debt Warrant
Certificate are exercised, the Company shall execute, and an authorized officer
of the Debt Warrant Agent shall countersign and deliver, a new Debt Warrant
Certificate evidencing the number of Debt Warrants remaining unexercised.

          d)  The Debt Warrant Agent shall deposit all funds received by it in
payment of the Debt Warrant Price in the account of the Company maintained with
it for such purpose and shall advise the Company by telephone by 5:00 P.M., New
York City time, of each day on which a payment of the Debt Warrant Price for
Debt Warrants is received of the amount so deposited in its account.  The Debt
Warrant Agent shall promptly confirm such telephone advice in writing to the
Company.

          e)  The Debt Warrant Agent shall, from time to time, as promptly as
practicable, advise the Company and the Trustee of (i) the number of Debt
Warrants of each title exercised as provided herein, (ii) the instructions of
each Holder with respect to delivery of the Underlying Debt Securities to which
such Holder is entitled upon such exercise, (iii) the delivery of Debt Warrant
Certificates evidencing the balance, if any, of the Debt Warrants remaining
unexercised after such exercise, and (iv) such other information as the Company
or the Trustee shall reasonably require.  Such notice may be given by telephone
to be promptly confirmed in writing.

          f)  The Company will pay all documentary stamp taxes attributable to
the initial issuance of Stock Warrants or to the issuance of Underlying Debt
Securities to the registered Holder of such Debt Securities upon exercise
thereof; provided, however, that the Holder, and not the Company, shall be
required to pay any stamp or other tax or other governmental charge that may be
imposed in connection with any transfer involved in the issuance of the
Underlying Debt Securities; and in the event that any such transfer is involved,
the Company shall not be required to issue any Underlying Debt Securities (and
the Holder's purchase of the Underlying Debt Securities upon the exercise of
such Holder's Debt Warrant shall not be deemed to have been consummated) until
such tax or other charge shall have been paid or it has been established to the
Company's satisfaction that no such tax or other charge is due.

                                  ARTICLE III
                 OTHER PROVISIONS RELATING TO RIGHTS OF HOLDERS
                                OF DEBT WARRANTS

     Section 3.01  No Rights as Holder of Underlying Debt Securities Conferred
                   -----------------------------------------------------------
by Debt Warrants or Debt Warrant Certificates.  No Debt Warrant or Debt Warrant
---------------------------------------------
Certificate shall

                                      -5-
<PAGE>

entitle the Holder to any of the rights of a holder of Underlying Debt
Securities, including, without limitation, the right to receive the payment of
principal of (or premium, if any, on) or interest, if any, on Underlying Debt
Securities or to enforce any of the covenants in the Indenture.

     Section 3.02  Lost, Stolen, Destroyed or Mutilated Debt Warrant
                   -------------------------------------------------
Certificates.  Upon receipt by the Company and the Debt Warrant Agent of
------------
evidence reasonably satisfactory to them of the ownership of and the loss,
theft, destruction or mutilation of any Debt Warrant Certificate and of
indemnity (other than in connection with any mutilated Debt Warrant Certificates
surrendered to the Debt Warrant Agent for cancellation) reasonably satisfactory
to them, the Company shall execute, and the Debt Warrant Agent shall countersign
and deliver, in exchange for or in lieu of each lost, stolen, destroyed or
mutilated Debt Warrant Certificate, a new Debt Warrant  Certificate evidencing a
like number of Debt Warrants of the same title.  Upon the issuance of a new Debt
Warrant Certificate under this Section, the Company may require the payment of a
sum sufficient to cover any stamp or other tax or other governmental charge that
may be imposed in connection therewith and any other expenses (including the
fees and expenses of the Debt Warrant Agent) in connection therewith.  Every
substitute Debt Warrant Certificate executed and delivered pursuant to this
Section in lieu of any lost, stolen or destroyed Debt Warrant Certificate shall
represent a contractual obligation of the Company, whether or not such lost,
stolen or destroyed Debt Warrant Certificate shall be at any time enforceable by
anyone, and shall be entitled to the benefits of this Agreement equally and
proportionately with any and all other Debt Warrant Certificates, duly executed
and delivered hereunder, evidencing Debt Warrants of the same title.  The
provisions of this Section are exclusive and shall preclude (to the extent
lawful) all other rights and remedies with respect to the replacement of lost,
stolen, destroyed or mutilated Debt Warrant Certificates.

     Section 3.03  Holder of Debt Warrants May Enforce Rights.  Notwithstanding
                   ------------------------------------------
any of the provisions of this Agreement, a Holder, without the consent of the
Debt Warrant Agent, the Trustee, the holder of any Underlying Debt Securities or
the Holder of any other Debt Warrant, may, on its own behalf and for its own
benefit, enforce, and may institute and maintain any suit, action or proceeding
against the Company to enforce, or otherwise in respect of, its right to
exercise its Debt Warrant or Debt Warrants in the manner provided in this
Agreement and its Debt Warrant Certificate.

                                   ARTICLE IV
                     EXCHANGE AND TRANSFER OF DEBT WARRANTS

     Section 4.01  Debt Warrant Register; Exchange and Transfer of Debt
                   ----------------------------------------------------
Warrants.  If registered Debt Warrants - The Debt Warrant Agent shall maintain,
at its corporate trust office or at __________, a register (the " Debt Warrant
Register") in which, upon the issuance of Debt Warrants and, subject to such
reasonable regulations as the Debt Warrant Agent may prescribe, it shall
register Debt Warrant Certificates and exchanges and transfers thereof.  The
Debt Warrant

                                      -6-
<PAGE>

Register shall be in written form or in any other form capable of being
converted into written form within a reasonable time.]

     Except as provided in the following sentence, upon surrender at the
corporate trust office of the Debt Warrant Agent or at __________ Debt Warrant
Certificates may be exchanged for one or more other Debt Warrant Certificates
evidencing the same aggregate number of Debt Warrants of the same title, or may
be transferred in whole or in part.  [If registered Debt Warrants - A transfer
shall be registered upon surrender of a Debt Warrant Certificate to the Debt
Warrant Agent at its corporate trust office or at __________ for transfer,
properly endorsed or accompanied by appropriate instruments of transfer and
written instructions for transfer, all in form satisfactory to the Company and
the Debt Warrant Agent duly signed by the registered holder or holders thereof
or by the duly appointed legal representative thereof or by a duly authorized
attorney, such signature to be guaranteed by (a) a bank or trust company, (b) a
broker or dealer that is a member of the National Association of Securities
Dealers, Inc. (the "NASD") or (c) a member of a national securities exchange.
Upon any such registration of transfer, a new Debt Warrant Certificate shall be
issued to the transferee.  Whenever a Debt Warrant Certificate is surrendered
for exchange or transfer, the Debt Warrant Agent shall countersign and deliver
to the person or persons entitled thereto one or more Debt Warrant Certificates
duly executed by the Company, as so requested.  The Debt Warrant Agent shall not
be required to effect any exchange or transfer which will result in the issuance
of a Debt Warrant Certificate evidencing a fraction of a Debt Warrant.  All Debt
Warrant Certificates issued upon any exchange or transfer of a Debt Warrant
Certificate shall be the valid obligations of the Company, evidencing the same
obligations, and entitled to the same benefits under this Agreement, as the Debt
Warrant Certificate surrendered for such exchange or transfer.

          No service charge shall be made for any exchange or transfer of Debt
Warrants, but the Company may require payment of a sum sufficient to cover any
tax or other governmental charge that may be imposed in connection with any such
exchange or transfer, in accordance with Section 2.02(f) hereof.

     Section 4.02  Treatment of Holders of Debt Warrants.  Every Holder of a
                   -------------------------------------
Debt Warrant, by accepting the Debt Warrant Certificate evidencing the same,
consents and agrees with the  Company, the Debt Warrant Agent and with every
other Holder of Debt Warrants of the same title that the Company and the Debt
Warrant Agent may treat the Holder of a Debt Warrant Certificate (or, if the
Debt Warrant Certificate is not then detachable, the Holder of the related
Offered Debt Security) as the absolute owner of such Debt Warrant for all
purposes and as the    person entitled to exercise the rights represented by
such Debt Warrant, any notice to the contrary notwithstanding.

     Section 4.03  Cancellation of Debt Warrant Certificates.  In the event that
                   -----------------------------------------
the Company shall purchase, redeem or otherwise acquire any Debt Warrants after
the issuance thereof, the Debt Warrant Certificate or Certificates evidencing
such Debt Warrants shall thereupon be delivered to the Debt Warrant Agent and be
canceled by it.  The Debt Warrant Agent shall also cancel any Debt Warrant
Certificate (including any mutilated Debt Warrant Certificate) delivered

                                      -7-
<PAGE>

to it for exercise, in whole or in part, or for exchange [or transfer] [if Debt
Warrant Certificates are issued in bearer form - , except that Debt Warrant
Certificates delivered to the Debt Warrant Agent in exchange for Debt Warrant
Certificates of other denominations may be retained by the Debt Warrant Agent
for reissue]. Debt Warrant Certificates so canceled shall be delivered by the
Debt Warrant Agent to the Company from time to time, or disposed of in
accordance with the instructions of the Company.



                                   ARTICLE V
                       CONCERNING THE DEBT WARRANT AGENT

     Section 5.01  Debt Warrant Agent.  The Company hereby appoints
                   ------------------
___________________ as Debt Warrant Agent of the Company in respect of the Debt
Warrants and the Debt Warrant Certificates upon the terms and subject to the
conditions set forth herein; and _______________ hereby accepts such
appointment.  The Debt Warrant Agent shall have the powers and authority granted
to and conferred upon it in the Debt Warrant Certificates and hereby and such
further powers and authority acceptable to it to act on behalf of the Company as
the Company may hereafter grant to or confer upon it.  All of the terms and
provisions with respect to such powers and authority contained in any Debt
Warrant Certificate are subject to and governed by the terms and provisions
hereof.

     Section 5.02  Conditions of Debt Warrant Agent's Obligations.   The Debt
                   ----------------------------------------------
Warrant Agent accepts its obligations set forth herein upon the terms and
conditions hereof, including the following, to all of which the Company agrees
and to all of which the rights hereunder of the Holders shall be subject:

          a)  Compensation and Indemnification.  The Company agrees to promptly
              --------------------------------
     pay the Debt Warrant Agent the compensation [set forth in Exhibit A hereto]
     and to reimburse the Debt Warrant Agent for reasonable out-of-pocket
     expenses (including counsel fees) incurred by the Debt Warrant Agent in
     connection with the services rendered hereunder by the Debt Warrant Agent.
     The Company also agrees to indemnify the Debt Warrant Agent for, and to
     hold it harmless against, any loss, liability or expense (including the
     reasonable costs and expenses of defending against any claim of liability)
     incurred without negligence or bad faith on the part of the Debt Warrant
     Agent arising out of or in connection with its appointment, status or
     service as Debt Warrant Agent hereunder.

          b)  Agent for the Company.  In acting under this Agreement and in
              ---------------------
     connection with any Debt Warrant Certificate, the Debt Warrant Agent is
     acting solely as agent of the Company and does not assume any obligation or
     relationship of agency or trust for or with any Holder.

                                      -8-
<PAGE>

          c)  Counsel.  The Debt Warrant Agent may consult with counsel
              -------
     satisfactory to it, and the advice of such counsel shall be full and
     complete authorization and protection in respect of any action taken,
     suffered or omitted by it hereunder in good faith and in accordance with
     the advice of such counsel.

          d)  Documents.  The Debt Warrant Agent shall be protected and shall
              ---------
     incur no liability for or in respect of any action taken, suffered or
     omitted by it in reliance upon any notice, direction, consent, certificate,
     affidavit, statement or other paper or document reasonably believed by it
     to be genuine and to have been presented or signed by the proper parties.

          e)  Officer's Certificate.  Whenever in the performance of its duties
              ---------------------
     hereunder the Debt Warrant Agent shall reasonably deem it necessary that
     any fact or matter be proved or established by the Company prior to taking,
     suffering or omitting any action hereunder, the Debt Warrant Agent may
     (unless other evidence in respect thereof be herein specifically
     prescribed), in the absence of bad faith on its part, rely upon a
     certificate signed by the Chairman of the Board of Directors, the Vice
     Chairman of the Board of Directors, the President, an Executive Vice
     President, and by the Treasurer, an Assistant Treasurer, the Secretary or
     an Assistant Secretary of the Company (an "Officer's Certificate")
     delivered by the Company to the Debt Warrant Agent.

          f)  Actions Through Agents.  The Debt Warrant Agent may execute and
              ----------------------
     exercise any of the rights or powers hereby vested in it or perform any
     duty hereunder either itself or by or through its attorneys or agents, and
     the Debt Warrant Agent shall not be answerable or accountable for any act,
     default, neglect or misconduct of any such attorney or agent or for any
     loss to the Company resulting from such neglect or misconduct; provided,
     however, that reasonable care shall have been exercised in the selection
     and continued employment of such attorneys and agents.

          g)  Certain Transactions.  The Debt Warrant Agent, and any officer,
              --------------------
     director or employee thereof, may become the owner of, or acquire any
     interest in, any Debt Warrant, with the same rights that he, she or it
     would have if it were not the Debt Warrant Agent, and, to the extent
     permitted by applicable law, he, she or it may engage or be interested in
     any financial or other transaction with the Company and may serve on, or as
     depository, trustee or agent for, any committee or body of holders of
     Underlying Debt Securities or other obligations of the Company as if it
     were not the Debt Warrant Agent.  Nothing in this Agreement shall be deemed
     to prevent the Debt Warrant Agent from acting as Trustee under the
     Indenture.

          h)  No Liability for Interest.  The Debt Warrant Agent shall not be
              -------------------------
     liable for interest on any monies at any time received by it pursuant to
     any of the provisions of this Agreement or of the Debt Warrant
     Certificates, except as otherwise agreed with the Company.

                                      -9-
<PAGE>

          i)  No Liability for Invalidity.  The Debt Warrant Agent shall incur
              ---------------------------
     no liability with respect to the validity of this Agreement (except as to
     the due execution hereof by the Debt Warrant Agent) or any Debt Warrant
     Certificate (except as to the countersignature thereof by the Debt Warrant
     Agent).

          j)  No Responsibility for Company Representations.  The Debt Warrant
              ---------------------------------------------
     Agent shall not be responsible for any of the recitals or representations
     contained herein (except as to such statements or recitals as describe the
     Debt Warrant Agent or action taken or to be taken by it) or in any Debt
     Warrant Certificate (except as to the Debt Warrant Agent's countersignature
     on such Debt Warrant Certificate), all of which recitals and
     representations are made solely by the Company.

          k)  No Implied Obligations.  The Debt Warrant Agent shall be obligated
              ----------------------
     to perform only such duties as are specifically set forth herein, and no
     other duties or obligations shall be implied.  The Debt Warrant Agent shall
     not be under any obligation to take any action hereunder that may subject
     it to any expense or liability, the payment of which within a reasonable
     time is not, in its reasonable opinion, assured to it.  The Debt Warrant
     Agent shall not be accountable or under any duty or responsibility for the
     use by the Company of any Debt Warrant Certificate countersigned by the
     Debt Warrant Agent and delivered by it to the Company pursuant to this
     Agreement or for the application by the Company of the proceeds of the
     issuance or exercise of Debt Warrants.  The Debt Warrant Agent shall have
     no duty or responsibility in case of any default by the Company in the
     performance of its covenants or agreements contained herein or in any Debt
     Warrant Certificate or in case of the receipt of any written demand from a
     Holder with respect to such default, including, without limiting the
     generality of the foregoing, any duty or responsibility to initiate or
     attempt to initiate any proceedings at law or otherwise or, except as
     provided in Section 6.04 hereof, to make any demand upon the Company.

     Section 5.03  Resignation and Removal; Appointment of Successor.  a)  The
                   -------------------------------------------------
Company agrees, for the benefit of the Holders of the Debt Warrants, that there
shall at all times be a Debt Warrant Agent hereunder until all the Debt Warrants
are no longer exercisable.

          b)  The Debt Warrant Agent may at any time resign as such by giving
written notice to the Company, specifying the date on which such resignation
shall become effective; provided that such date shall not be less than [90] days
after the date on which such notice is given, unless the Company agrees to
accept a shorter notice.  Such resignation is subject to the appointment and
acceptance of a successor Debt Warrant Agent, as hereinafter provided.  The Debt
Warrant Agent hereunder may be removed at any time by the filing with it of an
instrument in writing signed by or on behalf of the Company and specifying such
removal and the date when it shall become effective.  Notwithstanding the
provisions of this Section 5.03(b), such resignation or removal shall take
effect only upon the appointment by the Company, as

                                      -10-
<PAGE>

hereinafter provided, of a successor Debt Warrant Agent (which shall be a bank
or trust company organized and doing business under the laws of the United
States of America, any State thereof or the District of Columbia, authorized
under the laws of such jurisdiction to exercise corporate trust powers and
having at the time of its appointment as Debt Warrant Agent a combined capital
and surplus (as set forth in its most recent published report of financial
condition) of at least [$50,000,000]) and the acceptance of such appointment by
such successor Debt Warrant Agent. In the event a successor Debt Warrant Agent
has not been appointed and has not accepted its duties within [90] days of the
Debt Warrant Agent's notice of resignation, the Debt Warrant Agent may apply to
any court of competent jurisdiction for the designation of a successor Debt
Warrant Agent. The obligations of the Company under Section 5.02(a) shall
continue to the extent set forth therein notwithstanding the resignation or
removal of the Debt Warrant Agent.

          c)  In case at any time the Debt Warrant Agent shall resign, or shall
be removed, or shall become incapable of acting, or shall be adjudged a bankrupt
or insolvent, or shall file a petition seeking relief under Title 11 of the
United States Code, as now constituted or hereafter amended, or under any other
applicable federal or state bankruptcy law or similar law, or make an assignment
for the benefit of its creditors, or consent to the appointment of a receiver or
custodian for all or any substantial part of its property, or shall admit in
writing its inability to pay or meet its debts as they mature, or if a receiver
or custodian for it or for all or any substantial part of its property shall be
appointed, or if an order of any court shall be entered for relief against it
under the provisions of Title 11 of the United States Code, as now constituted
or hereafter amended, or under any other applicable federal or state bankruptcy
or similar law, or if any public officer shall have taken charge or control of
the Debt Warrant Agent or of its property or affairs for the purpose of
rehabilitation, conservation or liquidation, a successor Debt Warrant Agent,
qualified as aforesaid, shall be appointed by the Company by an instrument in
writing, filed with the successor Debt Warrant Agent.  Upon the appointment as
aforesaid of a successor Debt Warrant Agent and acceptance by the successor Debt
Warrant Agent of such appointment, the Debt Warrant Agent so superseded shall
cease to be Debt Warrant Agent hereunder.

          d)  Any successor Debt Warrant Agent appointed hereunder shall
execute, acknowledge and deliver to its predecessor and to the Company an
instrument accepting such appointment hereunder, and thereupon such successor
Debt Warrant Agent, without any further act, deed or conveyance, shall become
vested with all the authority, rights, powers, trusts, immunities, duties and
obligations of such predecessor with like effect as if originally named as Debt
Warrant Agent hereunder, and such predecessor, upon payment of its charges and
disbursements then unpaid, shall thereupon become obligated to transfer, deliver
and pay over, and such successor Debt Warrant Agent shall be entitled to
receive, [the Debt Warrant Register and] all monies, securities and other
property on deposit with or held by such predecessor (together with any books
and records relating thereto), as Debt Warrant Agent hereunder.

          e)  The Company shall cause notice of the appointment of any successor
Debt Warrant Agent to be [if registered Debt Warrants - mailed by first-class
mail, postage prepaid, to each Holder at its address appearing on the Debt
Warrant Register or, in the case of Debt

                                      -11-
<PAGE>

Warrants that are issued with Offered Debt Securities and cannot then be
transferred separately therefrom, on the security register for the Offered Debt
Securities] [if bearer Debt Warrants -published in an Authorized Newspaper (as
defined in Section 101 of the Indenture) in The City of New York and in such
other city or cities as may be specified by the Company at least twice, [the
first such publication to be not earlier than the earliest date and not later
than the latest date prescribed for the giving such notice]. Such notice shall
set forth the name and address of the successor Debt Warrant Agent. Failure to
give any notice provided for in this Section 5.03(e), or any defect therein,
shall not, however, affect the legality or validity of the appointment of the
successor Debt Warrant Agent.

          f)  Any corporation into which the Debt Warrant Agent hereunder may be
merged or converted, or any corporation with which the Debt Warrant Agent may be
consolidated, or any corporation resulting from any merger, conversion or
consolidation to which the Debt Warrant Agent shall be a party, or any
corporation to which the Debt Warrant Agent shall sell or otherwise transfer all
or substantially all of its assets and business, provided that such Corporation
shall be qualified as aforesaid, shall be the successor Debt Warrant Agent under
this Agreement without the execution or filing of any paper, the giving of any
notice to Holders or any further act on the part of the parties hereto.

     Section 5.04  Compliance With Applicable Laws.  The Debt Warrant Agent
                   -------------------------------
agrees to comply with all applicable federal and state laws imposing obligations
on it in respect of the services rendered by it under this Debt Warrant
Agreement and in connection with the Debt Warrants, including (but not limited
to) the provisions of United States federal income tax laws regarding
information reporting and backup withholding.  The Debt Warrant Agent expressly
assumes all liability for its failure to comply with any such laws imposing
obligations on it, including (but not limited to) any liability for failure to
comply with any applicable provisions of United States federal income tax laws
regarding information reporting and backup withholding.

     Section 5.05  Office.  The Company will maintain an office or agency where
                   ------
Debt Warrant Certificates may be presented for exchange, transfer or exercise.
The office initially designated for this purpose shall be the corporate trust
office of the Debt Warrant Agent at _____________.

                                   ARTICLE VI
                                 MISCELLANEOUS

     Section 6.01  Consolidation, Merger or Amalgamation of the Company and
                   --------------------------------------------------------
Conveyance or Transfer Permitted Subject to Certain Conditions.  To the extent
--------------------------------------------------------------
permitted in the Indenture, the Company may consolidate with or merge or
amalgamate into another corporation or other entity, or convey or transfer all
or substantially all of its properties and assets to any other corporation or
other entity.

                                      -12-
<PAGE>

     Section 6.02  Rights and Duties of Successor Corporation.  In case of any
                   ------------------------------------------
such consolidation, merger, conveyance or transfer and upon any assumption of
the duties and obligations of the Company by the successor corporation, such
successor corporation shall succeed to and be substituted for the Company, with
the same effect as if it had been named herein, and the Company shall be
relieved of any further obligation under this Agreement and the Debt Warrants.
Such successor corporation thereupon may cause to be signed, and may issue
either in its own name or in the name of the Company, any or all of the
Underlying Debt Securities issuable pursuant to the terms hereof.  All the
Underlying Debt Securities so issued shall in all respects have the same legal
rank and benefit under the Indenture as the Underlying Debt Securities
theretofore or thereafter issued in accordance with the terms of this Agreement
and the Indenture.

          In case of any such consolidation, merger, conveyance or transfer,
such changes in phraseology and form (but not in substance) may be made in the
Underlying Debt Securities thereafter to be issued as may be appropriate.

     Section 6.03  Supplements and Amendments.  a)  The Company and the Debt
                   --------------------------
Warrant Agent may from time to time supplement or amend this Agreement without
the approval or consent of any Holder in order to cure any ambiguity, to correct
or supplement any provision contained herein that may be defective or
inconsistent with any other provision herein, or to make any other provision in
regard to matters or questions arising hereunder that the Company and the Debt
Warrant Agent may deem necessary or desirable and that shall not adversely
affect the interests of the Holders.  Every Holder of Debt Warrants, whether
issued before or after any such supplement or amendment, shall be bound thereby.
Promptly after the effectiveness of any supplement or amendment that affects the
interests of the Holders, the Company shall give notice thereof, as provided in
Section 5.03(d) and 6.05 hereof, to the Holders affected thereby, setting forth
in general terms the substance of such supplement or amendment.

          b)  The Company and the Debt Warrant Agent may modify or amend this
Agreement and the Debt Warrant Certificates with the consent of the Holders of
not fewer than a majority in principal amount of the underlying Debt Securities
represented by the Debt Warrants affected by such modification or amendment, for
any purpose; provided, however, that no such modification or amendment that
shortens the period of time during which the Debt Warrants may be exercised, or
otherwise materially and adversely affects the exercise rights of the Holders or
reduces the percentage of Holders of outstanding Debt Warrants the consent of
which is required for modification or amendment of this Agreement or the Debt
Warrants, may be made without the consent of each Holder affected thereby.

     Section 6.04  Notices and Demands to the Company and Debt Warrant Agent.
                   ---------------------------------------------------------
If the Debt Warrant Agent shall receive any notice or demand addressed to the
Company by a Holder pursuant to the provisions of this Agreement or a Debt
Warrant Certificate, the Debt Warrant Agent shall promptly forward such notice
or demand to the Company.

                                      -13-
<PAGE>

     Section 6.05  Addresses.  Any communications from the Company to the Debt
                   ---------
Warrant Agent with respect to this Agreement shall be directed to
____________________, Attention: ____________________, and any communications
from the Debt Warrant Agent to the Company with respect to this Agreement shall
be directed to Global Crossing Ltd., Wessex House, 45 Reid Street, Hamilton
HM12, Bermuda, attention of General Counsel (or such other address as shall be
specified in writing by the Debt Warrant Agent or by the Company, as the case
may be).

     Section 6.06  Applicable Law.  This Agreement and the Debt Warrants shall
                   --------------
be governed by and construed in accordance with the laws of the State of New
York applicable to contracts made and to be performed entirely within such
State.

     Section 6.07  Delivery of Prospectus/Prospectus Supplement.  The Company
                   --------------------------------------------
will furnish to the Debt Warrant Agent sufficient copies of a prospectus,
prospectus supplement or prospectuses relating to the Underlying Debt Securities
deliverable upon exercise of any outstanding Debt Warrants (each a
"Prospectus"), and the Debt Warrant Agent agrees to deliver to the Holder of a
Debt Warrant, prior to or concurrently with the delivery of the Underlying Debt
Securities issued upon the exercise thereof, a copy of the Prospectus/Prospectus
Supplement relating to such Underlying Debt Securities.

     Section 6.08  Governmental Approvals.  The Company will use its reasonable
                   ----------------------
best efforts to obtain and keep effective any and all permits, consents and
approvals of governmental agencies and authorities and the national securities
exchange on which the Debt Warrants may be listed or authorized for trading from
time to time, and will make all filings under federal and state securities laws
(including, without limitation, the maintenance of the effectiveness of a
registration statement in respect of the Underlying Debt Securities under the
Securities Act of 1933), as may be or become requisite in connection with the
issuance, sale, transfer and delivery of Debt Warrants and Debt Warrant
Certificates, the exercise of Debt Warrants and the issuance, sale and delivery
of Underlying Debt Securities issued upon exercise of Debt Warrants.

     Section 6.09  Persons Having Rights under Debt Warrant Agreement.  Nothing
                   --------------------------------------------------
in this Agreement, expressed or implied, and nothing that may be inferred from
any of the provisions hereof is intended or shall be construed to confer upon or
give to any person or corporation other than the Company, the Debt Warrant Agent
and the Holders any right, remedy or claim under or by reason of this Agreement
or any covenant, condition, stipulation, promise or agreement herein; and all
covenants, conditions, stipulations, promises and agreements herein shall be for
the sole and exclusive benefit of the Company, the Debt Warrant Agent and their
respective successors and the Holders of Debt Warrant Certificates.

     Section 6.10  Headings.  The descriptive headings of the several Articles
                   --------
and Sections of this Agreement are inserted for convenience only and shall not
control or affect the meaning or construction of any of the provisions hereof.

                                      -14-
<PAGE>

     Section 6.11  Counterparts.  This Agreement may be executed in one or more
                   ------------
counterparts, each of which when so executed and delivered shall be deemed to be
an original; but all such counterparts taken together shall constitute one and
the same agreement.

     Section 6.12  Consent to Jurisdiction and Service.  To the fullest extent
                   -----------------------------------
permitted by applicable law, the Company hereby irrevocably submits to the
jurisdiction of any Federal or state court located in the Borough of Manhattan
in The City of New York, New York in any suit, action or proceeding based on or
arising out of or relating to this Agreement or any Securities and irrevocably
agrees that all claims in respect of such suit or proceeding may be determined
in any such court.  The Company irrevocably waives, to the fullest extent
permitted by law, any objection which it may have to the laying of the venue of
any such suit, action or proceeding brought in an inconvenient forum.  The
Company agrees that final judgment in any such suit, action or proceeding
brought in such a court shall be conclusive and binding upon the Company and may
be enforced in the courts of Bermuda (or any other courts to the jurisdiction of
which the Company is subject) by a suit upon such judgment, provided that
                                                            --------
service of process is effected upon the Company in the manner specified herein
or as otherwise permitted by law.  The Company hereby irrevocably designates and
appoints CT Corporation System, [                    ], New York, New York (the
AProcess Agent@) as the authorized agent of the Company, it being understood
that the designation and appointment of the Process Agent as such authorized
agent shall become effective immediately without any further action on the part
of the Company.  The Company further agrees that service of process upon the
Process Agent and written notice of said service to the Company mailed by
prepaid registered first class mail or delivered to the Process Agent at its
principal office, shall be deemed in every respect effective service of process
upon the Company in any such suit or proceeding. The Company further agrees to
take any and all action, including the execution and filing of any and all such
documents and instruments as may be necessary, to continue such designation and
appointment of the Process Agent in full force and effect so long as the Company
has any outstanding obligations under this Agreement.  To the extent the Company
has or hereafter may acquire any immunity from jurisdiction of any court or from
any legal process (whether through service of notice, attachment prior to
judgment, attachment in aid of execution, executor or otherwise) with respect to
itself or its property, the Company hereby irrevocably waives such immunity in
respect of its obligations under this Agreement, to the extent permitted by law.

                                      -15-
<PAGE>

     Section 6.13  Inspection of Agreement.  A copy of this Agreement shall be
                   -----------------------
available during business hours at the office of the Debt Warrant Agent for
inspection by any Holder.  The Debt Warrant Agent may require such Holder to
submit its Debt Warrant Certificate for inspection prior to making such copy
available.

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

                                    GLOBAL CROSSING LTD., a Bermuda company,

[Seal]

                                    By__________________________
Attest:                                  Name:
                                         Title:

_________________________________
Name and Title:




_________________________________
 [Seal]

 Attest:
                                    By__________________________
                                         Name and Title:

                                       _________________________
                                         Name and Title:

                                      -16-
<PAGE>

                                   Exhibit A
                                       to
                 [Senior] [Subordinated] Debt Warrant Agreement
                          dated as of __________, 19__



                      [Compensation of Debt Warrant Agent]

                                      -17-