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EXHIBIT 4.8

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WARRANT AGREEMENT

between

IMPSAT FIBER NETWORKS, INC.

and

THE BANK OF NEW YORK,
as Warrant Agent



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TABLE OF CONTENTS

|                                                                                                          |                                                                                                                                                                                                                                                                      |  |      |    | 
|--------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | ---- | -- | 
|                                                                                                          |                                                                                                                                                                                                                                                                      |  | Page
|                                                                                                          |                                                                                                                                                                                                                                                                      |  |     
|Parties                                                                                                   |                                                                                                                                                                                                                                                                      |  | 1    |   
|Recitals                                                                                                  |                                                                                                                                                                                                                                                                      |  | 1    |   
|ARTICLE I DEFINITIONS                                                                                     |                                                                                                                                                                                                                                                                      |  | 1    |   
|                                                                                                          | SECTION 1.01.          DEFINITIONS                                                                                                                                                                                                                                   |  |      | 1  | 
|                                                                                                          | SECTION 1.02.          TERMS GENERALLY                                                                                                                                                                                                                               |  |      | 4  | 
|                                                                                                          | SECTION 1.03.          ACCOUNTING TERMS AND DETERMINATIONS                                                                                                                                                                                                           |  |      | 5  | 
|ARTICLE II ISSUANCE, EXECUTION AND TRANSFER OF WARRANT CERTIFICATES                                       |                                                                                                                                                                                                                                                                      |  | 5    |   
|                                                                                                          | SECTION 2.01.          FORM OF WARRANT CERTIFICATES                                                                                                                                                                                                                  |  |      | 5  | 
|                                                                                                          | SECTION 2.02.          EXECUTION OF WARRANT CERTIFICATES                                                                                                                                                                                                             |  |      | 5  | 
|                                                                                                          | SECTION 2.03.          ISSUANCE, DELIVERY AND REGISTRATION OF WARRANT CERTIFICATES                                                                                                                                                                                   |  |      | 6  | 
|                                                                                                          | SECTION 2.04.          TRANSFER AND EXCHANGE OF WARRANT CERTIFICATES                                                                                                                                                                                                 |  |      | 6  | 
|ARTICLE III WARRANT PRICE, EXPIRATION DATE AND EXERCISE OF WARRANTS                                       |                                                                                                                                                                                                                                                                      |  | 8    |   
|                                                                                                          | SECTION 3.01.          WARRANT PRICE; EXPIRATION DATE                                                                                                                                                                                                                |  |      | 8  | 
|                                                                                                          | SECTION 3.02.          EXERCISE OF WARRANTS; COMMON STOCK RECORD DATE                                                                                                                                                                                                |  |      | 8  | 
|                                                                                                          | SECTION 3.03.          NO FRACTIONAL SHARES TO BE ISSUED                                                                                                                                                                                                             |  |      | 10 | 
|                                                                                                          | SECTION 3.04.          ACQUISITION OF WARRANTS BY THE COMPANY; CANCELLATION OF WARRANTS                                                                                                                                                                              |  |      | 11 | 
|ARTICLE IV ADJUSTMENT OF WARRANT PRICE, SHARES OF COMMON STOCK
SUBJECT TO PURCHASE AND NUMBER OF WARRANTS |                                                                                                                                                                                                                                                                      |  | 11   |   
|                                                                                                          | SECTION 4.01.          ADJUSTMENT OF WARRANT PRICE                                                                                                                                                                                                                   |  |      | 11 | 
|                                                                                                          | SECTION 4.02.          ELECTION TO ADJUST WARRANTS INSTEAD OF SHARES PER WARRANT                                                                                                                                                                                     |  |      | 17 | 
|                                                                                                          | SECTION 4.03.          NO FRACTIONAL WARRANTS TO BE ISSUED                                                                                                                                                                                                           |  |      | 17 | 
|                                                                                                          | SECTION 4.04.          RIGHTS UPON CONSOLIDATION, MERGER, SALE, TRANSFER OR RECLASSIFICATION                                                                                                                                                                         |  |      | 18 | 
|                                                                                                          | SECTION 4.05.          COVENANT TO RESERVE SHARES FOR ISSUANCE ON EXERCISE                                                                                                                                                                                           |  |      | 19 | 
|                                                                                                          | SECTION 4.06.          CONDITION PRECEDENT TO REDUCTION OF WARRANT PRICE BELOW PAR VALUE OF
                                 SHARES OF COMMON STOCK; COMPLIANCE WITH GOVERNMENTAL  REQUIREMENTS;
                                 SUSPENSION OF EXERCISE OF WARRANTS |  |      | 20 | 
|                                                                                                          | SECTION 4.07.          PAYMENT OF TAXES ON STOCK CERTIFICATES ISSUED UPON EXERCISE                                                                                                                                                                                   |  |      | 20 | 
|                                                                                                          | SECTION 4.08.          WARRANT AGENT NOT RESPONSIBLE FOR ADJUSTMENTS OR VALIDITY OF STOCK                                                                                                                                                                            |  |      | 20 | 
|                                                                                                          | SECTION 4.09.          STATEMENTS ON WARRANTS                                                                                                                                                                                                                        |  |      | 21 | 
|                                                                                                          | SECTION 4.10.          NO DILUTION OR IMPAIRMENT                                                                                                                                                                                                                     |  |      | 21 | 
|ARTICLE V OTHER PROVISIONS RELATING TO RIGHTS OF HOLDERS OF WARRANTS                                      |                                                                                                                                                                                                                                                                      |  | 21   |   
|                                                                                                          | SECTION 5.01.          ENFORCEMENT OF RIGHTS                                                                                                                                                                                                                         |  |      | 21 | 
|                                                                                                          | SECTION 5.02.          NO RIGHTS AS STOCKHOLDERS                                                                                                                                                                                                                     |  |      | 21 | 
|                                                                                                          | SECTION 5.03.          MUTILATED OR MISSING WARRANT CERTIFICATES                                                                                                                                                                                                     |  |      | 22 | 
|                                                                                                          | SECTION 5.04.          OBTAINING STOCK EXCHANGE LISTINGS                                                                                                                                                                                                             |  |      | 22 | 
|                                                                                                          | SECTION 5.05.          RULES 144 AND 144A                                                                                                                                                                                                                            |  |      | 22 | 
|                                                                                                          | SECTION 5.06.          1933 ACT AND APPLICABLE STATE SECURITIES LAWS                                                                                                                                                                                                 |  |      | 22 | 
|                                                                                                          | SECTION 5.07.          OBTAINING OF GOVERNMENTAL APPROVALS                                                                                                                                                                                                           |  |      | 23 | 
|                                                                                                          | SECTION 5.08.          DELIVERY OF PROSPECTUSES                                                                                                                                                                                                                      |  |      | 23 | 
|ARTICLE VI OTHER COVENANTS OF COMPANY                                                                     |                                                                                                                                                                                                                                                                      |  | 23   |   
|                                                                                                          | SECTION 6.01.          RESTRICTIONS ON PERFORMANCE                                                                                                                                                                                                                   |  |      | 23 | 

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|                                         |                                                                        |  |    |     | 
|---------------------------------------- | ---------------------------------------------------------------------- |  | -- | --- | 
|                                         | SECTION 6.02.          MODIFICATION OF RELATED AGREEMENTS              |  |    | 23  | 
|ARTICLE VII CONCERNING THE WARRANT AGENT |                                                                        |  | 24 |    
|                                         | SECTION 7.01.          PAYMENT OF CERTAIN TAXES                        |  |    | 24  | 
|                                         | SECTION 7.02.          CHANGE OF WARRANT AGENT                         |  |    | 24  | 
|                                         | SECTION 7.03.          COMPENSATION; FURTHER ASSURANCES                |  |    | 26  | 
|                                         | SECTION 7.04.          RELIANCE ON COUNSEL                             |  |    | 26  | 
|                                         | SECTION 7.05.          PROOF OF ACTIONS TAKEN                          |  |    | 26  | 
|                                         | SECTION 7.06.          CORRECTNESS OF STATEMENTS                       |  |    | 26  | 
|                                         | SECTION 7.07.          VALIDITY OF AGREEMENT                           |  |    | 27  | 
|                                         | SECTION 7.08.          USE OF AGENTS                                   |  |    | 27  | 
|                                         | SECTION 7.09.          LIABILITY OF WARRANT AGENT                      |  |    | 27  | 
|                                         | SECTION 7.10.          LEGAL PROCEEDINGS; EXPENSES                     |  |    | 27  | 
|                                         | SECTION 7.11.          OTHER TRANSACTIONS IN SECURITIES OF THE COMPANY |  |    | 27  | 
|                                         | SECTION 7.12.          ACTIONS AS AGENT                                |  |    | 28  | 
|                                         | SECTION 7.13.          APPOINTMENT AND ACCEPTANCE OF AGENCY            |  |    | 28  | 
|ARTICLE VIII MISCELLANEOUS PROVISIONS    |                                                                        |  | 28 |    
|                                         | SECTION 8.01.          AMENDMENTS, ETC                                 |  |    | 28  | 
|                                         | SECTION 8.02.          SUCCESSORS AND ASSIGNS                          |  |    | 29  | 
|                                         | SECTION 8.03.          NOTICES                                         |  |    | 29  | 
|                                         | SECTION 8.04.          APPLICABLE LAW                                  |  |    | 29  | 
|                                         | SECTION 8.05.          BENEFITS OF THIS AGREEMENT                      |  |    | 30  | 
|                                         | SECTION 8.06.          REGISTERED WARRANT HOLDERS                      |  |    | 30  | 
|                                         | SECTION 8.07.          INSPECTION OF AGREEMENT                         |  |    | 30  | 
|                                         | SECTION 8.08.          HEADINGS                                        |  |    | 30  | 
|                                         | SECTION 8.09.          COUNTERPARTS                                    |  |    | 30  | 
|                                         | EXHIBIT A                FORM OF WARANT CERTIFICATE                    |  |    | A-1 | 

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WARRANT AGREEMENT

THIS WARRANT AGREEMENT (this Agreement) dated as of March 25, 2003
between IMPSAT Fiber Networks, Inc., a Delaware corporation (including, on or
after the effective date of the Plan, as defined herein, its successor, as
reorganized pursuant to Chapter 11, Title 11 of the United States Bankruptcy
Code (the Bankruptcy Code)) (the Company), and the Warrant Agent as defined
herein.

WHEREAS, a plan of reorganization under Chapter 11 of the Bankruptcy Code
for the Company (the Plan) was confirmed on December 11, 2002 by order of the
United States Bankruptcy Court for the Southern District of New York (the
Bankruptcy Court), and has become effective; and

WHEREAS, the Plan provides for the execution and delivery of this
Agreement by the Company and the issuance of the Warrants (as defined herein)
on the terms and subject to the conditions herein set forth.

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

ARTICLE I

DEFINITIONS

SECTION 1.01.      Definitions. As used in this Agreement, the following terms
shall have the following respective meanings (all terms defined herein in the
singular are to have the correlative meanings when used in the plural and vice
versa):

1933 Act: shall mean the Securities Act of 1933, as amended from time to
time, or any successor statute, and the rules and regulations promulgated
thereunder.

Bankruptcy Code: shall have the meaning specified in the preamble.

Bankruptcy Court: shall have the meaning specified in the recitals.

Board of Directors: shall mean the Board of Directors of the Company.

Business Day: shall mean any day of the week other than a Saturday,
Sunday or a day on which commercial banks in New York City are authorized or
required by law to remain closed.

Case: shall mean the case filed in the Bankruptcy Court entitled In re
IMPSAT Fiber Networks, Inc., Debtor Chapter 11 Case No. 02-12882 (REG) under
the Bankruptcy Code.

Cashless Exercise and Cashless Exercise Ratio: shall have the meanings
specified in Section 3.02 herein.





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Commission: shall mean the U.S. Securities and Exchange Commission.

Common Stock: shall mean the Companys common stock, par value $0.01 per
share, as constituted on the Distribution Date and any stock into which such
common stock may thereafter be converted or changed, and also shall include any
other common stock of the Company of any other class. References herein and in
the Warrant to Common Stock outstanding on a fully diluted basis at any time
means the number of shares of Common Stock then issued and outstanding,
assuming full conversion, exercise and exchange of all Convertible Securities
and Rights that are (or may become) exchangeable for, or exercisable or
convertible into, Common Stock, including the Warrants.

Company: shall have the meaning specified in the preamble.

Control: shall mean the possession, directly or indirectly, of the power
to direct or cause the direction of the management or policies of a Person,
whether through the ability to exercise voting power, by contract or otherwise.
Controlling and Controlled shall have meanings correlative thereto.

Convertible Securities: shall mean evidences of indebtedness, interests
other securities or rights that are exchangeable for or exercisable or
convertible into shares of Common Stock, either immediately or upon the arrival
of a specified date or the occurrence of a specified event.

Distribution Date: shall mean the date of the original issuance of the
Warrant hereunder, which shall be March 25, 2003.

Exchange Act: means the Securities Exchange Act of 1934, as amended, or
any similar federal statute, and the rules and regulations of the Commission
thereunder, all as the same shall be in effect at the time.

Exercise Date: shall have the meaning specified in Section 3.02(a).

Expiration Date: shall mean 5:00 p.m., New York time, on the eighth
anniversary of the Initial Exercise Date.

Final Order: shall mean an order, judgment, ruling or other decree issued
and entered by the Bankruptcy Court (as entered on the docket in the Case), or
any state or federal court or other tribunal located in one of the states,
territories, or possessions of the United States of America or the District of
Columbia, which judgment, order or other decree has not been reversed, stayed,
modified or amended, and as to which (x) the time to appeal or to seek review,
rehearing or certiorari has expired and as to which no appeal or petition for
review, rehearing or certiorari is pending or has been timely filed, or (y) any
appeal that has been or may be taken or any petition for certiorari that has
been or may be filed has been resolved by the highest court to which the order or
judgment was appealed or from which certiorari was sought.

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GAAP: shall mean United States generally accepted accounting principles,
consistently applied throughout the relevant period.

HSR Act: shall mean the Hart-Scott-Rodino Antitrust Improvements Act of
1976, as amended.

Initial Exercise Date: shall mean the date on which the Plan becomes
effective pursuant to a Final Order of the Bankruptcy Court.

Lien: shall mean, with respect to any asset, any mortgage, lien, pledge,
charge, security interest or encumbrance of any kind in respect of such asset.
For purposes of this Agreement, a Person shall be deemed to own subject to a
Lien any asset that it has acquired or holds subject to the interest of a
vendor or lessor under any conditional sale agreement, capital lease or other
title retention agreement relating to such asset.

Officers Certificate: shall have the meaning specified in Section
4.01(e).

Option Plans: shall mean the Companys 2003 Stock Option Plan and any
stock option plan, stock grant plan, stock purchase, stock option or employment
arrangement approved from time to time by the Board of Directors, and any
modification, renewal or extension thereof if approved by the Board of
Directors.

Person: shall mean a natural person, a corporation, a partnership, a
trust, a joint venture, a governmental authority or any other entity or
organization.

Plan: shall have the meaning specified in the recitals.

Registration Rights Agreement: shall mean the Registration Rights
Agreement, dated as of the date hereof, among the Company, IMPSAT S.A. and the
holders listed on the signature pages thereto.

Related Agreements: shall mean the Registration Rights Agreement, the
certificate of incorporation of the Company and the by-laws of the Company.

Rights: shall mean any rights, options or warrants to subscribe for or
purchase, or any securities convertible into or exchangeable for, shares of
Common Stock.

Rule 144: shall mean Rule 144 (or any similar provision then in force)
under the 1933 Act.

Subsidiary: shall mean, with respect to any Person, (a) any corporation
more than 50% of the outstanding securities having ordinary voting power of
which shall at the time be owned or controlled, directly or indirectly, by such
Person and/or by one or more of its Subsidiaries, or (b) any company,
partnership, association, joint venture or similar business organization more
than 50% of the ownership interests having ordinary voting power of which shall at the time be directly or indirectly owned and
controlled by such Person and/or by one or more of its Subsidiaries.

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Warrant Agent: shall mean The Bank of New York or any successor to it
appointed pursuant to Section 7.02.

Transfer Restricted Security: shall mean any Warrant (and any Warrant
Stock underlying such Warrant) issued hereunder other than pursuant to the
exemption from registration under the 1933 Act provided under Section 1145(a)
of the Bankruptcy Code, until such security ceases to be a Transfer Restricted
Security as provided under Section 2.04 hereof.

Warrant Agents Office: shall mean, for so long as The Bank of New York
shall be the Warrant Agent, the address specified in Section 8.03 and,
thereafter, the office or agency maintained by the successor Warrant Agent in
the Borough of Manhattan, New York, New York or the principal office of the
successor Warrant Agent.

Warrant Certificates: shall have the meaning specified in Section 2.01.

Warrant Price: shall mean a price of $15.00 for each share of Common
Stock issuable upon exercise of a Warrant, as adjusted pursuant to Article IV.

Warrant Register: shall have the meaning specified in Section 2.03.

Warrant Shares: shall have the meaning specified in Section 4.01(h).

Warrant Stock: shall mean any shares of Common Stock issuable from time
to time upon exercise of any Warrant.

Warrants: shall mean the Warrants to purchase Common Stock, issued
pursuant to this Agreement, up to an aggregate (as adjusted pursuant to Article
IV) of 3,155,244 shares of Common Stock (which represents, as of the
Distribution Date, 15% of the outstanding shares of Common Stock on a fully
diluted basis), and any Warrant issued upon transfer, division or combination
of, or in substitution for, any thereof.

SECTION 1.02.      Terms Generally. The definitions of terms herein shall
apply to the singular and plural forms of the terms defined. Whenever the
context may require, any pronoun shall include the corresponding masculine,
feminine and neuter forms. The words include, includes and including
shall be deemed to be followed by the phrase without limitation. Unless the
context requires otherwise (a) any definition of or reference to any agreement,
instrument or other document herein shall be construed as referring to such
agreement, instrument or other document as from time to time amended,
supplemented or otherwise modified (subject to any restrictions on such
amendments, supplements or modifications set forth herein), (b) the words
herein, hereof and hereunder, and words of similar import, shall be
construed to refer to this Agreement in its entirety and not to any particular
provision hereof, and (c) all references herein to Articles, Sections (or subsections), Exhibits, Annexes and Schedules shall be construed to refer
to Articles and Sections (or subsections) of, and Exhibits, Annexes and
Schedules to, this Agreement or the Warrant, as the case may be, and (e) unless
the context otherwise requires, the words asset and property shall be
construed to have

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the same meaning and effect and to refer to any tangible and
intangible assets and properties, including cash, securities, accounts and
contract rights.

SECTION 1.03.      Accounting Terms and Determinations. Except as otherwise
may be expressly provided herein, all accounting terms used herein shall be
interpreted, and all financial statements and certificates and reports as to
financial matters required hereby to be delivered to any Person shall be
prepared, in accordance with GAAP.

ARTICLE II

ISSUANCE, EXECUTION AND TRANSFER OF WARRANT CERTIFICATES

SECTION
2.01.      Form of Warrant Certificates. The Warrants shall be
evidenced by certificates in definitive fully registered form (the Warrant
Certificates) substantially in the form of Exhibit A hereto, and designated as
Warrants to purchase Common Stock of IMPSAT Fiber Networks, Inc., and may have
such letters, numbers or other marks of identification and such legends or
endorsements placed thereon as may be required, in accordance with the advice
of counsel to the Company, to comply with any law or with any rule or
regulation made pursuant thereto or with any rule or regulation of any
securities exchange or automated quotation system, or to conform to customary
usage, or as may, consistently herewith, be determined to be necessary or
appropriate by the Company, as evidenced by the execution by the Companys
officers of the Warrant Certificates. The Warrant Certificates shall be in a
machine printable format and in a form reasonably satisfactory to the Warrant
Agent. Each Warrant Certificate shall evidence the right, subject to the
provisions of this Agreement and of the Warrant Certificate, to purchase one
share of Common Stock at the Warrant Price for each Warrant represented by
such Warrant Certificate, subject to adjustment pursuant to the provisions of
Article IV.

SECTION
2.02.      Execution of Warrant Certificates. Each Warrant
Certificate, whenever issued, shall be dated as of the date of countersignature
thereof by the Warrant Agent (either upon initial issuance or upon exchange,
substitution or transfer), shall be signed manually by, or bear the facsimile
signature of, the Chairman of the Board, the Chief Executive Officer, the
President or a Vice President of the Company, shall have the Companys seal or
a facsimile thereof affixed or imprinted thereon and shall be attested by the
manual or facsimile signature of the Secretary or an Assistant Secretary of the
Company. In case any officer of the Company whose manual or facsimile
signature has been placed upon any Warrant Certificate shall have ceased to be
such before such Warrant Certificate is issued, it may be issued with the same effect as if such officer had not ceased to be
such at the date of issuance. Warrant Certificates shall be countersigned by
the Warrant Agent and shall not be valid for any purpose unless so
countersigned. Warrant Certificates may be countersigned by the Warrant Agent,
with the same effect, notwithstanding that any Persons whose manual or
facsimile signatures appear thereon as proper officers of the Company shall
have ceased to be such officers at the time of such countersignature. Any
Warrant Certificate may be signed on behalf of the Company by any Person who,
at the actual date of the execution of such Warrant

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Certificate, shall be a
proper officer of the Company to sign such Warrant Certificate, although at the
date of the execution of this Agreement any such Person was not such an
officer.

SECTION 2.03.      Issuance, Delivery and Registration of Warrant Certificates.
The Company shall sign and deliver to the Warrant Agent, and the Warrant Agent
shall, and the Company shall cause the Warrant Agent to, countersign and
deliver to

(a)  Nortel Networks Limited or its assignees, on the Distribution Date,
two Warrant Certificates representing 953,689 Warrants and 1,714,286 Warrant,
respectively;

(b)  Sirti Argentina S.A. or its assignees, on the Distribution Date, 2
Warrant Certificates representing 238,045 Warrants and 82,276 Warrants,
respectively;

(c)  Citibank N.A. or its assignees, on the Distribution Date, Warrant
Certificates representing 82,802 Warrants;

(d)  Hughes Network Systems or its assignees, on the Distribution Date,
Warrant Certificates representing 33,934 Warrants;

(e)  DMC Stratex Networks, Inc. or its assignees, on the Distribution Date,
Warrant Certificates representing 14,831 Warrants;

(f)  Compaq Financial Services Argentina S.R.L. or its assignees, on the
Distribution Date, Warrant Certificates representing 10,682 Warrants;

(g)  El Camino Resources de America Latina, Inc. or its assignees, on the
Distribution Date, Warrant Certificates representing 23,249 Warrants;

(h)  Compaq Financial Services Ltda. or its assignees, on the Distribution
Date, Warrant Certificates representing 1,450 Warrants; and

The Warrant Agent shall, and the Company shall cause the Warrant Agent to,
countersign and deliver Warrant Certificates upon exchange or transfer of or
substitution for, one or more previously countersigned Warrant Certificates as
hereinafter provided. The Warrant Agent shall maintain the Companys books and
records (the Warrant Register) for the registration of Warrant Certificates
(including registration of the Warrant Certificates described above) and the
registration of transfers of Warrant Certificates after the Distribution Date.
The Company shall sign and deliver to the Warrant Agent an adequate supply of Warrant Certificates for the Warrant
Agent to perform its obligations pursuant to this Section 2.03 hereof.

SECTION 2.04.      Transfer and Exchange of Warrant Certificates.

(a)      Notwithstanding anything to the contrary contained herein, neither any
Warrant nor any Warrant Stock may be assigned or otherwise transferred to any
Person unless such transfer is made pursuant to an effective registration
statement or otherwise in accordance with the requirements of the 1933 Act and
applicable state securities laws.

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Until the Transfer Restricted Securities
cease to be Transfer Restricted Securities as hereinafter provided,
certificates evidencing Transfer Restricted Securities (and only such
certificates) will bear a legend in substantially the following form:

|                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|THE ISSUANCE OF THE SECURITIES REPRESENTED BY THIS
CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED (THE 1933 ACT)
OR PURSUANT TO THE SECURITIES LAWS OF ANY STATE, AND
SUCH SECURITIES MAY NOT BE SOLD OR TRANSFERRED OTHER
THAN IN ACCORDANCE WITH THE REGISTRATION
REQUIREMENTS OF THE 1933 ACT AND THE RULES AND
REGULATIONS THEREUNDER OR AN EXEMPTION THEREFROM AND
FROM ANY APPLICABLE STATE SECURITIES LAWS.

|                                                                                                                                                                                                                                                                                                                                                   
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE
THE BENEFITS OF A REGISTRATION RIGHTS AGREEMENT
DATED AS OF MARCH 25, 2003, AMONG THE COMPANY,
IMPSAT S.A., THE HOLDERS LISTED ON EXHIBIT A THERETO
AND SUCH OTHER PARTIES WHO MAY BE MADE A SIGNATORY
THERETO FROM TIME TO TIME, A COPY OF WHICH IS ON
FILE WITH THE SECRETARY OF THE COMPANY.

The Company shall instruct the Warrant Agent in writing of the Warrants
that should be so legended and shall supply the Warrant Agent with such
legended Warrant Certificates. For purposes of this Agreement, any such
securities shall cease to be Transfer Restricted Securities (i) when they have
been sold or otherwise disposed of (unless such securities are thereby acquired
and held by a Person who is an affiliate (within the meaning of Rule 144) of
the Company) pursuant to an effective registration statement under the 1933
Act, including any such registration statement filed pursuant to the
Registration Rights Agreement, (ii) when they may be distributed to the public
pursuant to Rule 144 by a Person who is not an affiliate (within the meaning of
Rule 144) of the Company, or (iii) when they have been distributed to the
public pursuant to Rule 144.

(b)        Subject to the first sentence of subsection (a) above, the Warrant
Agent, from time to time, shall register the transfer of all or any whole
number of Warrants covered by any outstanding Warrant Certificates in the
Warrant Register upon surrender at the Warrant Agents Office of Warrant
Certificates accompanied by a written instrument or instruments of transfer,
the form of assignment set forth on the Warrant Certificate or any other form
satisfactory to the Company and the Warrant Agent, duly executed by the
registered Warrant holder or such holders attorney duly authorized in writing.
Upon any such registration of transfer, a new Warrant Certificate shall be

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countersigned by the Warrant Agent and issued to the transferee and the
surrendered Warrant Certificate shall promptly be canceled by the Warrant
Agent. Warrant Certificates may be exchanged at the option of the holder
thereof, upon surrender, properly endorsed by the registered holders, at the
Warrant Agents Office, with written instructions, for other Warrant
Certificates countersigned by the Warrant Agent representing in the aggregate
the same number of Warrants. The Company or the Warrant Agent may require the
payment of a sum sufficient to cover any tax or governmental charge that may be
imposed in connection with any such exchange or transfer.

ARTICLE III

WARRANT PRICE, EXPIRATION DATE AND EXERCISE OF WARRANTS

SECTION 3.01.      Warrant Price; Expiration Date. Each Warrant Certificate
shall entitle the registered holder thereof, subject to the provisions thereof
and of this Agreement, to purchase from the Company at any time commencing at
the opening of business on the Initial Exercise Date and before 5:00 p.m., New
York time, on the Expiration Date, one share of Common Stock for each of the
Warrants specified therein, at the Warrant Price, subject to adjustment as
provided in Article IV hereof, payable in full at the time of purchase. Each
Warrant not exercised during the applicable period set forth above shall become
void.

SECTION 3.02.      Exercise of Warrants; Common Stock Record Date.

(a)      Commencing at the opening of business on the Initial Exercise Date,
Warrants may be exercised by the registered holders thereof as provided in this
Section 3.02. To exercise any Warrant, the registered holder thereof (A) must
surrender the Warrant Certificate evidencing such Warrant at the Warrant
Agents Office with the Election to Exercise form set forth on the Warrant
Certificate duly completed and executed by the registered holder thereof or
such holders attorney duly authorized in writing, (B) must pay in full to the
Warrant Agent for the account of the Company (i) in cash (including by wire
transfer to an account designated by the Company), (ii) by certified or
official bank check, (iii) by Cashless Exercise (as defined below) if otherwise
in compliance with applicable law, or (iv) by any combination of the foregoing,
the Warrant Price for each share of Common Stock as to which such Warrant is
exercised and any applicable taxes that the Company is not required to pay as
set forth in Section 4.07 or 7.01, (C) if applicable, must have satisfied any
necessary filing requirements under the HSR Act, in respect of its acquisition of the
shares of Common Stock upon such exercise and the waiting period under such HSR
Act shall have expired or been terminated without objection to such
acquisition, and (D) if such exercise would cause control of the Company to
change for purposes of the rules, regulations and policies of the Federal
Communications Commission (the FCC), must have received the consent or
approval of the FCC to such change in control (which consent or approval the
Company agrees to use its reasonable efforts to assist and cooperate with such
registered holder in promptly seeking and obtaining). The date on which such
holder satisfies all of those requirements is the Exercise Date. A Cashless
Exercise shall

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mean an exercise of a Warrant in accordance with the
immediately following two sentences. To effect a Cashless Exercise, the holder
may exercise a Warrant or Warrants without payment of the Warrant Price in cash
by surrendering such Warrant or Warrants (represented by one or more Warrant
Certificates) and, in exchange therefor, receiving such number of shares of
Common Stock equal to the product of (1) that number of shares of Common Stock
for which such Warrant or Warrants are exercisable and which would be issuable
in the event of an exercise with full payment in cash of the Warrant Price and
(2) the Cashless Exercise Ratio (as defined below). The Cashless Exercise
Ratio shall equal a fraction, the numerator of which is the excess of the
current market price (calculated as set forth in Section 4.01(e) herein) per
share of Common Stock on the date of exercise over the Warrant Price per share
of Common Stock as of the date of exercise and the denominator of which is the
current market price (calculated as set forth in Section 4.01(e) herein) per
share of Common Stock on the date of exercise. A registered Warrant holder may
exercise all or any number of whole Warrants represented by a Warrant
Certificate. Upon surrender of a Warrant Certificate representing more than
one Warrant in connection with a holders option to elect a Cashless Exercise,
such holder must specify the number of Warrants for which such Warrant
Certificate is to be exercised (without giving effect to such Cashless
Exercise). All provisions of this Agreement shall be applicable with respect
to a Cashless Exercise of a Warrant Certificate for less than the full number
of Warrants represented thereby.

(b)        Subject to the provisions of subsection (e) below and Section 4.07
hereof, as soon as practicable (and in any event within five (5) Business Days)
after the Exercise Date, the Warrant Agent shall promptly requisition from the
transfer agent of the Common Stock and deliver to or upon the order of such
registered Warrant holder a certificate or certificates for the number of full
shares of Common Stock to which such Warrant holder is entitled, registered in
such name or names as may be directed by such holder (if other than to such
registered holder, (i) to the extent such transfer is not validly restricted
and (ii) upon payment of any transfer taxes that are required to be paid by
such holder or its transferees in connection with any transfer by such
registered holder), together with cash, as provided in Section 3.03 hereof, in
respect of any fractional shares, and, if the number of Warrants represented by
a Warrant Certificate shall not have been exercised in full, a new Warrant
Certificate delivered to the holder of the Warrant Certificate or to such
holders duly authorized assignee, countersigned by the Warrant Agent, for the
number of Warrants remaining unexercised, together with cash, as provided in
Section 4.03 hereof, in respect of the balance of any fractional Warrants
represented by the surrendered Warrant Certificate. Any shares of Common Stock
issued upon a Warrant holders exercise of any Warrant shall be validly
authorized and issued,fully paid, non-assessable, free of preemptive rights and free from all
taxes (other than those specified in clause (ii) above), liens, charges,
security interests and claims created or incurred by the Company in respect of
the issuance thereof.

(c)      A Warrant shall be deemed to have been exercised immediately prior to
the close of business on the Exercise Date. Each Person in whose name any such
certificate for shares of Common Stock is issued shall for all purposes be
deemed to have become the holder of record of such shares at the close of
business on the Exercise Date, irrespective of the date of delivery of such
share certificate, except that, if the Exercise

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Date is a date when the stock transfer books of the Company are closed, such Person shall be deemed to have
become the holder of such shares at the close of business on the next
succeeding date on which the stock transfer books are open (whether before or
after the Expiration Date).

(d)        The Warrant Agent shall promptly notify both the Company and the
transfer agent of the Common Stock in writing of any exercise of any Warrants,
of the number of Warrants being exercised, the amount of money (if any)
received by it upon the exercise of the Warrants and (after receipt, where
applicable, from the Company of the Cashless Exercise Ratio) of the number of
shares delivered upon the exercise of such Warrants, and shall pay to the
Company within 72 hours after receipt by wire transfer or certified or official
bank check payable to the order of the Company the amount of money received by
it upon the exercise of Warrants (less any amount paid by the Warrant Agent in
respect of a fractional share upon such exercise in accordance with Section
3.03 hereof). The Warrant Agent shall hold any proceeds collected and not yet
paid to the Company in a federally insured escrow account. If there is a
Cashless Exercise with respect to such Warrants, the Company shall promptly
calculate and transmit notice to the Warrant Agent of the Cashless Exercise
Ratio. A detailed accounting statement setting forth the number of Warrants
exercised, the amount of funds received and the number of shares issued in
connection with such exercise and all expenses incurred by the Warrant Agent as
provided in this Agreement shall be transmitted to the Company on payment to
the Company of the funds so received upon exercise. The Warrant Agent shall
render to the Company a complete accounting setting forth the number of
Warrants exercised, the identity of the Persons exercising such Warrants, the
number of shares issued, the amounts distributed to the Company and all
expenses incurred by the Warrant Agent as provided in this Agreement as of the
Expiration Date.

(e)        Subject to Section 8.06 hereof, if the Warrant Agent is instructed to
deliver shares upon the exercise of Warrants or to deliver a Warrant
Certificate representing unexercised Warrants, in either case registered in a
name or names other than the name or names in which a Warrant Certificate
tendered in connection with such exercise is registered, the Warrant Agent may
require such documents, and such evidence of payment of applicable transfer
taxes, as it may reasonably deem necessary to enable it to carry out the
instructions of the bearer.

(f)        The Warrant Agent may assume that any Warrant exercised is permitted
to be exercised under applicable law and shall have no liability for acting in
reliance upon such assumption.

SECTION
3.03.      No Fractional Shares to
Be Issued. Notwithstanding anything
to the contrary contained in this Agreement, if the number of shares of Common
Stock purchasable on the exercise of each Warrant is adjusted pursuant to the
provisions of Section 4.02 hereof, the Company shall not be required to issue
any fraction of a share of Common Stock or to distribute stock certificates
that evidence fractional shares of Common Stock. If Warrant Certificates
evidencing more than one Warrant shall be surrendered for exercise at one time
by the same holder, the number of full shares that shall be issuable upon
exercise thereof shall be computed on the basis of the aggregate

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number of Warrants so surrendered. If any fraction of a share of Common Stock would,
except for the provisions of this Section 3.03, be issuable on the exercise of
any Warrant or Warrants, the Company shall purchase such fraction for an amount
in cash equal to the then-current market price of such fraction computed in
accordance with Section 4.01(e) hereof (assuming, for the purpose of such
computation, that the date of surrender of such Warrants to the Warrant Agent
shall be the applicable record date referred to in Section 4.01(e)). The
Warrant holders, by their acceptance of the Warrant Certificates, expressly
waive their right to receive any fraction of a share of Common Stock (other
than in cash as provided in this Section 3.03) or a stock certificate
representing a fraction of a share of Common Stock.

SECTION 3.04.      Acquisition of Warrants by the Company; Cancellation of
Warrants. The Company shall have the right, except as limited by law or other
agreement, to purchase or otherwise acquire Warrants at such times, in such
manner and for such consideration as it may deem appropriate; provided that
nothing herein shall provide the Company with the right to require any Person
to sell or dispose of any Warrants. The Warrant Agent shall cancel any Warrant
Certificate delivered to it for exercise, in whole or in part, or delivered to
it for transfer, exchange, or substitution, and no Warrant Certificates shall
be issued in lieu thereof unless such exercise, transfer, exchange or
substitution is expressly permitted by the provisions of this Agreement. On
request of the Company, the Warrant Agent shall deliver canceled Warrant
Certificates held by it to the Company. If the Company shall acquire any of
the Warrants, such acquisition shall not operate as a redemption or termination
of the right represented by such Warrants unless and until the Warrant
Certificates evidencing such Warrants are surrendered to the Warrant Agent for
cancellation.

ARTICLE IV

ADJUSTMENT OF WARRANT PRICE, SHARES OF COMMON STOCK
SUBJECT TO PURCHASE AND NUMBER OF WARRANTS

SECTION 4.01.      Adjustment of Warrant Price.

The Warrant Price specified in Section 3.01 shall be subject to adjustment
from time to time as follows:

(a)      If the Company after the date hereof shall (i) pay a dividend or make
a distribution in the form of Common Stock or other shares of capital stock of
the Company to the holders of Common Stock, (ii) subdivide or split the
outstanding shares of Common Stock into a larger number of shares of Common
Stock, or (iii) combine the outstanding shares of Common Stock into a smaller
number of shares of Common Stock, then in any such case the Warrant Price in
effect immediately prior thereto shall be adjusted to a price obtained by
multiplying such Warrant Price by a fraction of which the numerator shall be
the number of shares of Common Stock outstanding prior to such action and the
denominator shall be the number of shares of Common Stock outstanding after
giving effect to such action. An adjustment made pursuant to clause (i) of
this subsection (a) shall become effective retroactively immediately after the
record date for

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such dividend or distribution, and an adjustment made pursuant
to clause (ii) or (iii) of this subsection (a) shall become effective
immediately after the effective date of such subdivision or combination.

(b)        If the Company after the date hereof shall issue Rights to the holders
of Common Stock or any class thereof entitling such holders (in the case of
rights, options or warrants), for a period expiring within 45 days after the
record date mentioned below, to subscribe for or purchase shares of Common
Stock or any class thereof or (in the case of convertible or exchangeable
securities) to convert such securities into, or exchange them for, shares of
Common Stock or any class thereof, in each case, at a price per share of Common
Stock (or, in the case of convertible or exchangeable securities, having an
effective initial offering price per share of Common Stock, based upon (x) the
initial offering price of such securities, (y) the initial conversion or
exchange ratio of such securities and (z) any additional consideration
initially payable upon conversion or exchange) less than the then-current
market price per such share (as determined pursuant to subsection (e) below)
(each, a Below-Market Rights Issuance) on the record date mentioned below,
the Warrant Price in effect immediately prior thereto shall be adjusted to a
price obtained by multiplying such Warrant Price by a fraction of which (i) the
numerator shall be (A) the number of shares of Common Stock outstanding on such
record date plus (B) the number of additional shares of Common Stock that the
aggregate offering price of the total number of shares of Common Stock (or, in
the case of convertible or exchangeable securities, that the aggregate
effective initial offering price for the shares of Common Stock to be delivered
upon conversion or exchange of such convertible or exchangeable securities,
based upon (x) the initial offering price of such convertible or exchangeable
securities, (y) the initial conversion or exchange ratio of such securities and
(z) any additional consideration initially payable upon conversion or exchange)
so to be offered would purchase at the then-current market price of the Common
Stock, and (ii) the denominator shall be (A) the number of shares of Common
Stock outstanding on such record date plus (B) the number of additional shares
of Common Stock to be offered for subscription or purchase (or, as the case may
be, into or for which the convertible or exchangeable securities so to be
offered are initially convertible or exchangeable). Any such adjustments shall
be made whenever such Rights are issued and shall become effective
retroactively immediately after the record date for the determination of
stockholders entitled to receive such Rights. Upon expiration of the period
during which any such Rights may be exercised, any adjustment previously made pursuant to the foregoing provisions shall be recalculated
to take into consideration only those Rights actually exercised during the
applicable period for exercise and notice of any such further adjustment to the
Warrant Price shall be given to Warrant holders as herein provided; provided,
however, that no such readjustment shall have the effect of increasing the
Warrant Price above the amount, or of decreasing the number of shares of Common
Stock purchasable upon the exercise of Warrants below the number, in effect
immediately prior to the adjustment to which such readjustment applies. The
provisions of this Section 4.01(b) shall apply to Below-Market Rights Issuance
to Persons other than the holders of Common Stock or any class thereof,
provided, however, that references in this Section 4.01(b) (1) to current
market price per share of Common Stock shall be to the product of (i) such
current market price as determined pursuant to

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subsection (e) below and (ii) 0.85, (2) to rights, options or warrants shall be
to all rights, options or warrants, without regard to their expiration date,
and (3) to record date shall be to the date of issuance of the Rights.

(c)      If the Company after the date hereof shall issue or distribute to the
holders of Common Stock or any class thereof evidences of its indebtedness or
assets (excluding any cash dividend or distribution paid out of retained
earnings (as such term is used in GAAP)), Rights (other than Rights for which
an adjustment to the Warrant Price is made pursuant to Section 4.01(b)), or
shares of capital stock of any class (other than the Common Stock) or rights to
subscribe therefor (such indebtedness, assets, Rights, shares and rights to
subscribe therefor, a Distribution), in each such case the Warrant Price in
effect immediately prior thereto shall be adjusted to a price obtained by
multiplying such Warrant Price by a fraction of which (i) the numerator shall
be (A) the then-current market price per share (determined as provided in
subsection (e) below) of the Common Stock of each class of Common Stock,
multiplied by the number of outstanding shares of such class, less (B) the
then-current fair market value (as determined by the Board of Directors by a
duly adopted resolution in its reasonable and good faith judgment whose
determination shall be final and binding and shall be described in a
statement filed with the Warrant Agent, a copy of which statement shall be sent
by the Warrant Agent to the Warrant holders upon their written request) of the
aggregate amount of the Distribution, and (ii) the denominator shall be (A) the
then-current market price per share (determined as provided in subsection (e)
below) of the Common Stock of each class of Common Stock, multiplied by the
number of outstanding shares of such class, in each case, on the record date
mentioned below. The Company shall provide the Warrant Agent with any
indenture or other instrument defining the rights of the holders of any
Distribution referred to in this subsection 4.01(c). Any such adjustment shall
be made whenever any such Distribution is made and shall become effective
retroactively immediately after the record date for the determination of
stockholders entitled to receive such Distribution. Upon expiration of the
period during which any rights or securities granted pursuant to this
subsection (c) may be exercised, converted or exchanged, as the case may be,
any adjustment previously made pursuant to the foregoing provisions shall be
recalculated to take into consideration only those rights and securities
actually exercised, converted and exchanged, as the case may be, during the
applicable period for exercise, conversion and exchange, and notice of any such
further adjustment to the Warrant Price shall be given to Warrant holders as
herein provided.

(d)      If the Company after the date hereof shall issue shares of Common
Stock to the holders of Common Stock or any class thereof at a price per share
of Common Stock less than the then-current market price per such share (as
determined pursuant to subsection (e) below) (a Below-Market Common Stock
Issuance) on the date the Company issues such additional shares, the Warrant
Price in effect immediately prior thereto shall be adjusted to a price obtained
by multiplying such Warrant Price by a fraction of which (i) the numerator
shall be (A) the number of shares of Common Stock outstanding on the date of
issuance of such additional shares of Common Stock plus (B) the number of
additional shares of Common Stock that the aggregate consideration received for
the issuance of such additional shares would purchase at the then-current
market price of the Common Stock, and (ii) the denominator shall be the number
of

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shares of Common Stock outstanding immediately after the issuance of such
additional shares. The provisions of this Section 4.01(d) shall apply to
Below-Market Common Stock Issuance to Persons other than the holders of Common
Stock or any class thereof, provided, however, that references in this Section
4.01(d) to current market price per share of Common Stock shall be to the
product of (i) such current market price as determined pursuant to subsection
(e) below and (ii) 0.85.

(e)      The current market price per share of any class of Common Stock on any
date shall be deemed to be the average of the daily mean between the high and
low sales prices, regular way, of the shares of such class of Common Stock on
the exchange on which such shares are listed as specified below for the twenty
consecutive Trading Days (as defined below) preceding such date. If there
shall not have been a sale, regular way, on any such Trading Day, the mean of
the last reported bid and asked quotations regular way on the exchange
specified below on such day shall be deemed to be the only sale price. The
exchange specified for purposes of this subsection (e) shall be: (i) the New
York Stock Exchange, Inc. or the Nasdaq National Market; or (ii) if the shares
of the applicable class of Common Stock are not listed thereon, then that
national securities
exchange on which the applicable class of Common Stock is listed having
the largest volume of trading in the applicable class of Common Stock during
the calendar year or portion thereof next preceding such computation;
provided,
however, that if the shares of the applicable class of Common Stock shall not
be listed on any such exchange on any such twenty Trading Days, the average of
the closing high bid and low asked prices for the applicable class of Common
Stock in the over-the-counter market on each Trading Day on which such shares
are not so listed, as reported by the National Association of Securities
Dealers Automatic Quotation System or, if not so reported, then as reported by
the National Quotation Bureau Incorporated, or if such organization is not in
existence, by an organization providing similar services (as determined by the
Board of Directors of the Company), shall be deemed to be the only sale price
on such Trading Day); or (iii) if the shares of the applicable class of Common
Stock shall not be so reported on any of such Trading Days, then the current
market price per share of such class shall be the fair market value thereof as
determined in the reasonable and good faith judgment of the Board of Directors
whose determination shall be final and binding and shall be described in a
statement filed with the Warrant Agent. For the purpose of this subsection
(e), Trading Day shall mean a day on which the securities exchange specified
for purposes of this subsection (e) shall be open for business or, if the
shares of the applicable class of Common Stock shall not be listed on such
exchange for such period, a day with respect to which quotations of the
character specified for purposes of this subsection (e) shall be reported.

(f)      In any case in which this Section 4.01 shall require that an
adjustment be made retroactively immediately following a record date, the
Company may elect to defer (but only until five Business Days following the
filing by the Company with the Warrant Agent of a certificate signed by the
Chairman of the Board, Chief Executive Officer, the President or any Vice
President of the Company (an Officers Certificate) as required in subsection
(i) of this Section 4.01) issuing to the holder of any Warrant exercised after
such record date the shares of Common Stock issuable upon such exercise in
excess of the shares of Common Stock issuable upon such exercise prior to such
adjustment.

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(g)      No adjustment shall be required unless such adjustment would require
an increase or decrease in the Warrant Price then subject to adjustment of at
least one percent (1%) of such Warrant Price; provided,
however, that any
adjustments that are not made by reason of this subsection (g) shall be carried
forward and taken into account in any subsequent adjustment. All calculations
under this Section 4.01 shall be made to the nearest thousandth of a cent. If
any action would require adjustment of the Warrant Price or the property into
which Common Stock is convertible or exchangeable pursuant to more than one of
the provisions described in this Article IV in a manner such that such
adjustments are duplicative, only one adjustment shall be made and such
adjustment shall be the amount of adjustment that has the highest absolute
value to the holders of the Warrants.

(h)      Unless the Company shall have exercised its election as provided in
Section 4.02, upon each adjustment of the Warrant Price as a result of the
calculations made in this Section 4.01(a), (b), (c) and (d), the number of
shares of Common Stock purchasable upon exercise of a Warrant (the
Warrant
Shares) shall be increased to the
product (calculated by the nearest thousandth) obtained by multiplying the
number of shares of Common Stock purchasable upon exercise of the Warrants
immediately prior to such adjustment by a fraction, the numerator of which
shall be the Warrant Price in effect immediately prior to such adjustment and
the denominator of which shall be the Warrant Price in effect immediately after
such adjustment.

(i)      Whenever an adjustment in the Warrant Price is made as required or
permitted by the provisions of Sections 4.01 of this Agreement, the Company
shall promptly file with the Warrant Agent an Officers Certificate setting
forth the adjusted Warrant Price as provided in this Section 4.01 and either
the adjusted number of Warrants Shares as provided in this Section 4.01 or the
adjusted number of outstanding Warrants as provided in Section 4.02, and
setting forth in reasonable detail the facts requiring such adjustment and the
computation thereof (and the number of shares of Common Stock (or portions
thereof) subject to purchase upon exercise of a Warrant after such adjustment),
and shall promptly mail or cause to be mailed a notice of such adjustment to
each registered Warrant holder at such holders last address as the same
appears on the Warrant Register. The Warrant Agent shall be under no duty or
responsibility with respect to any such certificate except to exhibit the same
to any holder of Warrants desiring inspection thereof. The Warrant Agent shall
not be deemed to have knowledge of such adjustment unless and until such
certificate shall have been delivered to it in accordance with Section 8.03.
Upon the written request of any registered Warrant holder, the Company shall
also promptly deliver a copy of such certificate to the Companys transfer
agent.

(j)        In case:



| |                                                                                                                             
| | ----------------------------------------------------------------------------------------------------------------------------
| | (1)      the Company shall declare a dividend (or any other distribution)
on shares of Common Stock or any class thereof; or

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| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (2)      the Company shall authorize the granting to the holders of
shares of Common Stock or any class thereof of rights to subscribe for or
purchase any shares of capital stock of any class or of any other right;
or                                                                                                                                                                                                                                          
|
| | (3)      of any reclassification of shares of Common Stock or any class
thereof (other than a subdivision or combination of outstanding shares of
Common Stock or any class thereof) or of any consolidation or merger to
which the Company is a party and, in each case, for which approval of any
stockholders of the Company is required, or of the sale or transfer of
all or substantially all of the assets of the Company (which requires
such approval); or
|
| | (4)      of the voluntary or involuntary dissolution, liquidation or
winding up of the Company;                                                                                                                                                                                                                                                                                                                                                                    

then the Company shall cause to be filed with the Warrant Agent, and shall
cause to be mailed to the holders of the Warrants, at their last addresses as
they shall appear upon the Warrant Register, at least 20 days prior to the
applicable date hereinafter specified, a notice stating (x) the date on which a
record is to be taken for the purpose of such
dividend, distribution or rights, or, if a record is not to be taken, the date
as of which the holders of Common Stock (or any class thereof) entitled to such
dividend, distribution or rights are to be determined, or (y) the date on which
such reclassification, consolidation, merger, sale, transfer, dissolution,
liquidation or winding up is expected to become effective, and, if applicable,
the date as of which it is expected that holders of Common Stock (or any class
thereof) of record shall be entitled to exchange their shares of Common Stock
for securities or other property (including cash) deliverable upon such
reclassification, consolidation, merger, sale, transfer, dissolution,
liquidation or winding up; provided, however, that a failure to give any such
notice, or any defect therein, shall not affect the validity of the proceedings
referred to in clauses (1), (2), (3) or (4) above.

(k)      The Company shall be entitled, but not required, to make such
reductions in the Warrant Price, in addition to those required by this Section
4.01, as it in its discretion shall determine to be advisable (as evidenced in
a duly adopted resolution of the Board of Directors), including in order that
any dividend in or distribution of shares of Common Stock (or any class
thereof) or shares of capital stock of any class other than Common Stock,
subdivision, reclassification or combination of shares of Common Stock,
issuance of Rights, or any other transaction having a similar effect, shall not
be treated as a distribution of property by the Company to its stockholders
under Section 305 of the Internal Revenue Code of 1986, as amended or any
successor provision and shall not be taxable to them.

(l)      Notwithstanding anything to the contrary contained in this Agreement,
no adjustment to the Warrant Price or in the number of outstanding Warrants
shall be made as a result of, or in connection with (i) the issuance of options
or rights to purchase Common Stock issued to directors, officers or employees
of the Company or its Subsidiaries pursuant to any Option Plan, or (ii) the
issuance of shares of Common Stock or other securities issued by the Company
pursuant to and in accordance with the Plan.

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SECTION
4.02.      Election to Adjust Warrants
Instead of Shares Per Warrant.
The Company may elect, on or after the date of any adjustment of the Warrant
Price pursuant to Section 4.01 hereof, to increase the number of Warrants
outstanding in substitution for any adjustment in the number of Warrant Shares
pursuant to Section 4.01(h). The aggregate Warrants outstanding immediately
after such adjustment in the number of Warrants shall be exercisable for the
same number of shares of Common Stock for which the aggregate Warrants
outstanding immediately prior to such adjustment would have been exercisable
had the Company instead elected to adjust the number of Warrant Shares pursuant
to Section 4.01(h). Each Warrant held of record prior to such adjustment of
the number of Warrants shall become that number of Warrants (calculated to the
nearest thousandth) obtained by (i) multiplying the number of Warrants held of
record prior to adjustment of the number of Warrants by the Warrant Price in
effect prior to adjustment of the Warrant Price pursuant to Section 4.01
hereof, and (ii) dividing the product so obtained by the Warrant Price in
effect after adjustment of the Warrant Price pursuant to Section 4.01 hereof.
The Warrant Price shall remain unchanged by any adjustment to the number of
outstanding Warrants pursuant to this Section 4.02. The Company shall make a
public announcement of its election to adjust
the number of Warrants, indicating the record date for the adjustment,
and, if known at the time, the amount of the adjustment to be made. The record
date may be the date on which the Warrant Price is adjusted or any day
thereafter, but shall not be less than 10 or more than 30 days later than the
date of public announcement. Upon each adjustment of the number of Warrants
pursuant to this Section 4.02, the Company shall cause the Warrant Agent, as
promptly as practicable, to distribute to holders of record of the Warrant
Certificates on such record date either (i) Warrant Certificates evidencing,
subject to Section 4.03, any additional Warrants to which such holders shall be
entitled as a result of such adjustment, or (ii) at the option of the Company,
in substitution and replacement for the Warrant Certificates held by such
holders prior to the date of adjustment, and upon surrender thereof (if
required by the Company), new Warrant Certificates evidencing all the Warrants
to which such holders shall be entitled after such adjustment. Warrant
Certificates to be so distributed shall be issued, executed and countersigned
in the manner specified in this Agreement (but shall bear, if the Company
elects to replace Warrant Certificates pursuant to clause (ii) above, the
Warrant Price as adjusted pursuant to Section 4.01 hereof), shall represent the
same class of Warrants as was represented by the Warrant Certificates so
surrendered and shall be registered in the names of the holders of record of
the Warrant Certificates on the record date specified in the public
announcement.

For the purposes of this Section 4.02, public announcement shall mean
publication at least once in a newspaper printed in the English language and
customarily published at least once a day for at least five days in each
calendar week and of general circulation in the Borough of Manhattan, New York,
New York.

SECTION
4.03.      No Fractional Warrants to
Be Issued. Notwithstanding
anything to the contrary contained in this Agreement, the Company shall not be
required to issue fractions of Warrants on any distribution of Warrants to
Warrant holders pursuant to Section 4.02 hereof or otherwise or to distribute
Warrant Certificates that evidence fractional Warrants. If any fraction of a
Warrant would, except for the

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provisions of this Section 4.03, be issuable upon
an adjustment of the Warrant Price and distribution of Warrants pursuant to
Section 4.02 hereof or otherwise, the Company shall purchase such fraction for
an amount in cash equal to the then-current market value of such fraction
computed in accordance with Section 4.01(e) hereof (with respect to the current
market price of the Warrant rather than the per share current market price of
the Common Stock and assuming, for the purpose of such computation, that the
effective date of such adjustment of the Warrant Price, or such other relevant
date, shall be the applicable record date referred to in Section 4.01(e)). The
Warrant holders, by their acceptance of the Warrant Certificates, expressly
waive their right to receive any fraction of a Warrant (other than in cash as
provided in this Section 4.03) or a Warrant Certificate representing a fraction
of a Warrant upon the adjustment thereof in accordance with this Article IV or
otherwise.

SECTION
4.04.      Rights Upon
Consolidation, Merger, Sale, Transfer or Reclassification.

(a)      In case of any reclassification or change of the shares of Common
Stock issuable upon exercise of the Warrants (other than a change in par value,
or from par value to no par value, or as a result of a subdivision or
combination), any consolidation of the Company with or merger of the Company
into another Person, any merger of another Person into the Company (other than
a merger or consolidation that does not result in any reclassification,
conversion, exchange or cancellation of outstanding shares of Common Stock of
the Company) or any lease, sale or conveyance to another Person of the property
of the Company as an entirety or substantially as an entirety in one or a
series of related transactions, lawful provision shall be made as part of the
terms of such transaction or transactions and as a condition thereto, and in a
supplemental agreement hereto, whereby the holder of each Warrant then
outstanding shall have the right thereafter (until the Expiration Date) to
receive, upon exercise thereof, in lieu of each share of Common Stock
deliverable upon such exercise immediately prior to such event, the kind and
amount of shares and/or other securities and/or property and/or cash receivable
upon such reclassification, consolidation, merger, lease, sale or conveyance by
a holder of one share of Common Stock, including provisions pursuant to
subsection (f) below.

(b)      In case of any liquidation, dissolution or winding up of the affairs
of the Company, the Company shall, subject to applicable law, make prompt,
proportionate, equitable, lawful and adequate provision as part of the terms of
such dissolution, liquidation or winding up such that the holder of a Warrant
may thereafter receive, on exercise of such Warrant, in lieu of each share of
Common Stock of the Company which such holder would have been entitled to
receive upon exercise of such Warrant, the same kind and amount of any stock,
securities or assets as may be issuable, distributable or payable on any such
dissolution, liquidation or winding up with respect to each share of Common
Stock of the Company; provided, however, that in the event of any such
dissolution, liquidation or winding up, the right to exercise the Warrants
shall terminate on a date fixed by the Company, such date to be not earlier
than the 60th day next succeeding the date on which notice of such termination
of the right to exercise the Warrants has been given by mail to the holders
thereof in accordance with Section 4.01(i).

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(c)       Any supplemental agreement entered into pursuant to Section 4.04(a)
shall, as applicable, state the Warrant Price in terms of one full share of
Common Stock of the Company or one full share of the common stock of any
successor, leasing or purchasing Person.

(d)      The above provisions of this Section 4.04 shall similarly apply,
mutatis mutandis, to successive reclassifications and changes of shares of
Common Stock and to successive consolidations, mergers, leases, sales or
conveyances.

(e)       Notice of the execution of any supplemental agreement entered into
pursuant to Section 4.04(a) shall be mailed by the Company to registered
holders of Warrants as soon as practicable after the execution of such
supplemental agreement.

(f)       In the event that at any time as a result of the provisions of this
Section 4.04, the holder of any Warrant thereafter surrendered for exercise
shall become entitled to receive any shares or other securities other than
shares of Common Stock, thereafter the price or prices of such other shares or
other securities so receivable upon exercise of any Warrant shall be subject to
adjustment from time to time in a manner and on terms as nearly equivalent as
practicable to the provisions of Article IV with respect to Common Stock, and
the provisions of the other Articles of this Agreement (including Article III)
with respect to Common Stock shall apply on like terms to any such other shares
or other securities.

SECTION
4.05.      Covenant to Reserve
Shares for Issuance on Exercise. The
Company covenants that it will at all times reserve and keep available free of
preemptive or similar rights out of its authorized and unissued Common Stock,
solely for the purpose of issue upon exercise of Warrants as herein provided,
the full number of shares of Common Stock, if any, then issuable if all
outstanding Warrants then exercisable were to be exercised. The Company
covenants that all shares of Common Stock which shall be so issuable shall be
duly and validly issued, fully paid and non-assessable and shall not be subject
to preemptive or similar rights, and shall be free from taxes, liens, charges
or security interests thereto (other than those created by holders of the
Warrants or by former holders of the Warrants in their capacity as such
holders) the Company and entitled to the benefit of the Registration Rights
Agreement as provided therein.

The Company hereby authorizes and directs its current and future transfer
agents for the Common Stock and for any shares of the Companys capital stock
issuable upon the exercise of any of the Warrants at all times to reserve such
number of authorized shares as shall be requisite for such purpose. The
Warrant Agent is hereby authorized to requisition from time to time from any
such transfer agents stock certificates required to honor outstanding Warrants
upon exercise thereof in accordance with the terms of this Agreement, and the
Company hereby authorizes and directs such transfer agents to comply with all
such requests of the Warrant Agent. The Company will supply such transfer
agents with duly executed stock certificates for such purposes and will provide
or otherwise make available any cash which may be payable as provided in this
Article IV. Promptly after the Expiration Date, the Warrant Agent shall
certify to the Company the

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aggregate number of Warrants then outstanding, and
thereafter no shares shall be reserved in respect of such Warrants.

SECTION
4.06.      Condition Precedent to Reduction of Warrant Price Below Par
Value of Shares of Common Stock; Compliance with Governmental
Requirements;
Suspension of Exercise of Warrants. Before taking any action that would cause
an adjustment reducing the Warrant Price to below the then par value of any of
the shares of Common Stock issuable upon exercise of the Warrants, the Company
will take any corporate action that may, in the opinion of its counsel, be
necessary in order that the Company may validly and legally issue fully paid
and non-assessable shares of such Common Stock at such adjusted Warrant Price.

The Company covenants that if any shares of Common Stock required to be
reserved for purposes of exercise of Warrants require, under any federal or
state law or rule or regulation of any national securities exchange or market,
registration with or approval of any governmental authority, or listing on any
national securities exchange or market before such shares may be issued upon
exercise, the Company will in good faith and as expeditiously as possible
endeavor to cause such shares to be duly registered, approved or listed on the
relevant national securities exchange or market, as the case may be;
provided,
however, that in no event shall such shares of Common Stock be issued, and the
Company is hereby authorized to suspend the exercise of all Warrants, for the
period during which such registration, approval or listing is required but not
in effect.

SECTION
4.07.      Payment of Taxes on Stock
Certificates Issued upon Exercise.
The initial issuance or delivery of certificates of Common Stock upon the
exercise of Warrants shall be made without charge to the exercising Warrant
holders for any transfer, stamp or similar tax or for any other governmental
charges that may be imposed in respect of the issuance or delivery of such
stock certificates, and such stock certificates shall be issued in the
respective names of, or in such names as may be directed by, the registered
holders of the Warrants exercised; provided, however, that the Company shall
not be required to pay any tax or such other charges that may be payable in
respect of any transfer involved in the issuance and delivery of any such stock
certificate, any Warrant Certificates or other securities in a name other than
that of the registered holder of the Warrant Certificate surrendered upon
exercise of the Warrant, and the Company shall not be required to issue or
deliver such certificates or other securities unless and until the Person or
Persons requesting the issuance thereof shall have paid to the Company the
amount of such tax or shall have established to the reasonable satisfaction of
the Company that such tax has been paid.

SECTION
4.08.      Warrant Agent Not Responsible for Adjustments or Validity of
Stock. The Warrant Agent shall not at any time be under any duty or
responsibility to any Warrant holder to determine whether any facts exist that
may require an adjustment of the Warrant Price, or with respect to the nature
or extent of any such adjustment when made, or with respect to the method
employed herein or in any supplemental agreement
in making the same. The Warrant Agent shall not be accountable with
respect to the validity or value (or the kind or amount) of any shares of
Common Stock or of any securities or property which may at any time be issued
or

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delivered upon the exercise of any Warrant or upon any adjustment pursuant
to this Article IV, and it makes no representation with respect thereto. The
Warrant Agent shall not be responsible for any failure of the Company to make
any cash payment or to issue, transfer or deliver any shares of Common Stock or
stock certificates or other securities or property upon the surrender of any
Warrant for the purpose of exercise or upon any adjustment pursuant to this
Article IV, or to comply with any of the covenants of the Company contained in
this Article IV.

SECTION
4.09.      Statements on
Warrants. The form of Warrant Certificate
need not be changed because of any adjustment made pursuant to this Article IV,
and Warrant Certificates issued after such adjustment may state the same
Warrant Price and the same number of shares of Common Stock as are stated in
the Warrant Certificates initially issued pursuant to this Agreement. The
Company, however, may at any time in its sole discretion (which shall be
conclusive) make any change in the form of Warrant Certificate that it may deem
appropriate and that does not affect the substance thereof; and any Warrant
Certificate thereafter issued or countersigned, whether in exchange or
substitution for an outstanding Warrant Certificate or otherwise, may be in the
form as so changed.

SECTION
4.10.      No Dilution or
Impairment.

The Company shall not participate in any reorganization, transfer of
assets, consolidation, merger, dissolution, issue or sale of securities or any
other voluntary action for the purpose of avoiding or seeking to avoid the
observance or performance of any of the terms to be observed or performed
hereunder by the Company.

ARTICLE V

OTHER PROVISIONS RELATING TO RIGHTS OF HOLDERS OF WARRANTS

SECTION
5.01.      Enforcement of Rights. Notwithstanding any of the
provisions of this Agreement, without the consent of the Warrant Agent, the
holder of any Warrant may, in and for his, her or its own behalf, enforce, and
may institute and maintain any suit, action or proceeding against the Company
suitable to enforce, his, her or its right to exercise the Warrant or Warrants
evidenced by such holders Warrant Certificate in the manner provided in such
Warrant Certificate and in this Agreement. Because a breach of the provisions
of this Agreement could not adequately be compensated by money damages, holders
of Warrants shall be entitled, in addition to any other right or remedy
available to them, to an injunction restraining such breach or a threatened
breach and to specific performance of any such provision of this Agreement, and
in either case no bond or other security shall be required
in connection therewith, and the parties hereby consent to the issuance of
such injunction and to the ordering of specific performance by a court of
competent jurisdiction.

SECTION
5.02.      No Rights as
Stockholders. Nothing contained in this
Agreement or in any Warrant Certificate shall be construed as conferring, prior
to the date of exercise of such Warrant, on the holder of any Warrant or its
transferee any rights

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whatsoever as a stockholder of the Company, either at law
or equity, including but not limited to the right to vote at, or to receive
notice of, any meeting of stockholders of the Company; nor shall any such
holder, by reason of the ownership or possession of a Warrant or the Warrant
Certificate representing the same, either at, before or after exercising such
Warrant, have any right to receive any cash dividends, stock dividends,
allotments or rights, or other distributions (except as specifically provided
herein), paid, allotted or distributed or distributable to the stockholders of
the Company as stockholders of the Company prior to the date of the exercise of
such Warrant.

SECTION
5.03.      Mutilated or Missing
Warrant Certificates. If any Warrant
Certificate is lost, stolen, mutilated or destroyed, the Company shall issue or
cause to be issued, and the Warrant Agent shall countersign, in exchange and
substitution for and upon cancellation of the mutilated Warrant Certificate, or
in lieu of and substitution for the Warrant Certificate lost, stolen, mutilated
or destroyed, upon receipt of a proper affidavit or other evidence satisfactory
to the Company and the Warrant Agent (and surrender of any mutilated Warrant
Certificate) and indemnity in form and amount reasonably satisfactory to the
Company and the Warrant Agent in each instance protecting the Company and the
Warrant Agent, a new Warrant Certificate of like tenor and representing an
equivalent number of Warrants as the Warrant Certificate so lost, stolen,
mutilated or destroyed. Any such new Warrant Certificate shall constitute an
original contractual obligation of the Company, whether or not the allegedly
lost, stolen, mutilated or destroyed Warrant Certificate shall be at any time
enforceable by anyone. An applicant for such a substitute Warrant Certificate
shall also comply with such other reasonable regulations and pay such other
reasonable charges as the Company or the Warrant Agent may prescribe.

SECTION
5.04.      Obtaining Stock Exchange
Listings. The Company will from
time to time take all action which may be necessary so that the shares of
Common Stock issuable upon the exercise of Warrants, immediately upon such
issuance, will be listed on the principal securities exchanges and markets
within the United States or Canada (including the Nasdaq National Market), if
any, on which other shares of Common Stock are then listed or quoted.

SECTION
5.05.      Rules 144 and
144A. While any Warrants remain outstanding,
the Company covenants that it shall file the reports required to be filed by it
under the Exchange Act, and the rules and regulations adopted by the Commission
thereunder, in a timely manner in accordance
with the requirements of the Exchange Act. If at any time the Company is
not required to file such reports, it will distribute to each holder or
beneficial owner of Warrants that are restricted securities within the
meaning of Rule 144 and are not saleable in full under paragraph (k) of Rule
144, such information as is necessary to permit sales pursuant to Rule 144A
under the 1933 Act.

SECTION
5.06.      1933 Act and Applicable
State Securities Laws. The Company
shall comply with all applicable laws, including the 1933 Act and any
applicable state securities laws, in connection with the offer and sale of
Common Stock (and other securities and property deliverable) upon exercise of
the Warrants.

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SECTION
5.07.      Obtaining of Governmental
Approvals. In the event that the
Warrants are registered pursuant to an effective registration statement under
the 1933 Act, the Company will from time to time take all action required to be
taken by it which may be necessary to obtain and keep effective any and all
permits, consents and approvals of governmental agencies and authorities and
securities acts filings under United States federal and state laws, if
applicable, and the rules and regulations of all stock exchanges on which the
Warrants are listed which may be or become requisite in connection with (i) the
issuance, sale, transfer, and delivery to the Company of the Warrant
Certificates, (ii) the exercise of the Warrants or (iii) the issuance, sale,
transfer and delivery by the Company of the shares of Common Stock issued upon
the exercise of the Warrants.

SECTION
5.08.      Delivery of
Prospectuses. If, and to the extent that, the
Company may be required by the 1933 Act or any other applicable federal or
state law to furnish a prospectus to Warrant holders upon their exercise of
Warrants, the Company shall cause to be kept, either at the Warrant Agents
Office or at such other location designated by the Company, sufficient
quantities of such prospectuses for delivery to Warrant holders upon their
exercise of Warrants, and shall deliver such prospectuses or cause such
prospectuses to be delivered to such Warrant holders together with the shares
of Common Stock or other securities receivable by such Warrant holders upon
their exercise of Warrants.

ARTICLE VI

OTHER COVENANTS OF COMPANY

The Company agrees with each of the Warrant holders, for so long as the
Warrants shall be outstanding, as follows:

SECTION
6.01.      Restrictions on
Performance.

The Company shall not at any time enter into any agreement or other
instrument that would make the performance of the Companys obligations under
this Agreement,
including the issuance of Warrant Stock upon the exercise of the Warrant,
a breach of or default under such agreement or instrument.

SECTION
6.02.      Modification of Related
Agreements.

The Company shall not amend, or consent to any modification, supplement or
waiver of any provision of any Related Agreements after the date hereof, which
modification, supplement or waiver would (a) restrict the transferability of
the Warrant or (unless the restriction applies to the Common Stock in addition
to the Warrant Stock) of the Warrant Stock, (b) restrict the transferability of
the rights of a holder under this Agreement to any transferee of all or a
portion of such holders Warrants or (c) require any consent or other approval
of any Person to the exercise of the Warrant or the issuance Warrant Stock upon
such exercise.

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ARTICLE VII

CONCERNING THE WARRANT AGENT

SECTION 7.01.      Payment of Certain Taxes. The Company will from time to
time promptly pay all transfer, stamp or similar taxes and all other
governmental charges that may be imposed upon the Company or otherwise in
respect of the initial issuance of the Warrants and the initial issuance or
delivery of shares of Common Stock upon the exercise of Warrants, but the
Company shall not be obligated to pay any transfer, stamp or similar taxes or
other governmental charges in respect of any transfer of the Warrants or of
such shares effected by any holder thereof.

SECTION 7.02.       Change of Warrant Agent.

(a)        The Warrant Agent, or any successor to it hereafter appointed, may
resign its duties and be discharged from all further duties and liabilities
hereunder (except liabilities arising as a result of the Warrant Agents own
negligence, willful misconduct or bad faith) after giving 30 days notice in
writing to the Company, except that such shorter notice may be given as the
Company shall, in writing, accept as sufficient. At least 15 days prior to the
date such resignation is to become effective, the Warrant Agent shall cause a
copy of such notice of resignation to be mailed to the registered holder of
each Warrant Certificate. If the office of the Warrant Agent becomes vacant by
resignation or incapacity to act or otherwise, the Company shall appoint a
successor Warrant Agent in place of the Warrant Agent. If the Company shall
fail to make such appointment within a period of 30 days after it has been
notified in writing of such resignation or incapacity by the resigning or
incapacitated Warrant Agent or by the registered holder of any Warrant
Certificate, then the Warrant Agent or the registered holder of any Warrant
Certificate may apply, at the expense of the Company, to any court of competent
jurisdiction for the appointment of a new Warrant Agent.

(b)        The Warrant Agent may be removed by the Company at any time upon 30
days written notice to the Warrant Agent; provided, that the Warrant Agent
shall not be
removed until a successor Warrant Agent meeting the qualifications hereof
shall have been appointed.

(c)      Any successor Warrant Agent, whether appointed by the Company or by a
court, shall be a corporation or banking association organized, in good
standing and doing business under the laws of the United States of America or
any state thereof or the District of Columbia, and authorized under such laws
to exercise corporate trust powers and subject to supervision or examination by
federal or state authority and having a combined capital and surplus of not
less than $10,000,000. The combined capital and surplus of any such successor
Warrant Agent shall be deemed to be the combined capital and surplus as set
forth in the most recent report of its condition published prior to its
appointment pursuant to law or to the requirements of a federal or state
supervising or examining authority. After appointment, any successor Warrant
Agent shall be vested with all the authority, powers, rights, immunities,
duties and obligations of its predecessor Warrant Agent with like effect as if
originally named as Warrant Agent

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hereunder, without any further assurance,
conveyance, act or deed; provided, however, that in no event shall any
successor Warrant Agent be liable for any breach, default or failure of
performance by the predecessor Warrant Agent of any covenant or obligation
under this Agreement existing on the date the successor Warrant Agent assumes
authority pursuant to this Section 7.02. If for any reason it becomes
necessary or appropriate, the predecessor Warrant Agent shall execute and
deliver, at the expense of the Company, an instrument transferring to such
successor Warrant Agent all the authority, powers and rights of such
predecessor Warrant Agent hereunder; and upon request of any successor Warrant
Agent, the Company shall make, execute, acknowledge and deliver any and all
instruments in writing to more fully and effectively vest in and confirm to
such successor Warrant Agent all such authority, powers, rights, immunities,
duties and obligations. Upon assumption by a successor Warrant Agent of the
duties and responsibilities hereunder, the predecessor Warrant Agent shall,
upon payment of its charges hereunder, deliver and transfer, at the expense of
the Company, to the successor Warrant Agent any property at the time held by it
hereunder and, if for any reason it becomes necessary or expedient to have the
former Warrant Agent execute and deliver any further assurance, conveyance, act
or deed, the same shall be done at the expense of the Company and shall be
legally and validly executed and delivered by the former Warrant Agent. As
soon as practicable after such appointment, the Company shall give notice
thereof to the predecessor Warrant Agent, the registered holders of the
Warrants and each transfer agent for the shares of its Common Stock. Failure
to give such notice, or any defect therein, shall not affect the validity of
the appointment of the successor Warrant Agent.

(d)        Any corporation into which the Warrant Agent may be merged or with
which it may be consolidated, or any corporation resulting from any merger or
consolidation to which the Warrant Agent shall be a party, or any corporation
or banking association succeeding to all or substantially all the stock
transfer business of the Warrant Agent, meeting the requirements for successor
Warrant Agents under Section 7.02(c) hereunder (including execution of an
instrument to assume the duties and responsibilities of a Warrant Agent
hereunder), shall be the successor Warrant Agent under this Agreement without
any further act, provided that such corporation is eligible for appointment as
a successor to the Warrant Agent. Any such successor Warrant Agent
shall promptly cause notice of its succession as Warrant Agent to be
mailed to the Company and to the registered holder of each Warrant Certificate.
In case at the time such successor Warrant Agent shall succeed to the agency
created by this Agreement, any of the Warrant Certificates shall have been
countersigned but not delivered, any such successor Warrant Agent may adopt the
countersignature of the original Warrant Agent and deliver such Warrant
Certificates so countersigned, and in case at that time any of the Warrant
Certificates shall not have been countersigned, any successor to the Warrant
Agent may countersign such Warrant Certificates either in the name of the
predecessor Warrant Agent or in the name of the successor Warrant Agent; and in
all such cases Warrant Certificates shall have the full force provided in the
Warrant Certificates and in this Agreement.

(e)        In case at any time the name of the Warrant Agent shall be changed and
at such time any of the Warrant Certificates shall have been countersigned but
not delivered, the Warrant Agent may adopt the countersignatures under its
prior name and

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deliver such Warrant Certificates so countersigned; and in case
at that time any of the Warrant Certificates shall not have been countersigned,
the Warrant Agent may countersign such Warrant Certificates either in its prior
name or in its changed name; and in all such cases such Warrant Certificates
shall have the full force provided in the Warrant Certificates and in this
Agreement.

SECTION 7.03.      Compensation; Further Assurances. The Company agrees (i)
that it will pay the Warrant Agent such fees as shall have been agreed in
writing between the Company and the Warrant Agent for its services as Warrant
Agent hereunder and, except as otherwise expressly provided, will pay or
reimburse the Warrant Agent upon demand for all reasonable expenses,
disbursements and advances incurred or made by the Warrant Agent in accordance
with any of the provisions of this Agreement (including the reasonable
compensation, expenses and disbursements of its agents and counsel) except any
such expense, disbursement or advance as may arise from its or any of their
gross negligence, willful misconduct or bad faith; and (ii) that it will
perform, execute, acknowledge and deliver or cause to be performed, executed,
acknowledged and delivered all such further and other acts, instruments and
assurances as may reasonably be required by the Warrant Agent for the carrying
out or performing of the provisions of this Agreement. The provisions of this
section shall survive the expiration of the Warrants and the termination of
this Agreement.

SECTION
7.04.      Reliance on Counsel. The Warrant Agent may consult with
legal counsel of its selection (who may be legal counsel for the Company), and
the opinion or advice of such counsel shall be full and complete authorization
and protection to the Warrant Agent as to any action taken or omitted by it in
good faith and in accordance with such written opinion or advice, provided that
such counsel shall be reasonably acceptable to the Company.

SECTION 7.05.      Proof of Actions Taken.
Whenever in the performance of its duties under this Agreement the Warrant
Agent shall deem it necessary or desirable that any matter be proved or
established by the Company prior to taking or suffering or omitting any action
hereunder, such matter (unless other evidence in respect thereof be herein
specifically prescribed) may, in the absence of bad faith on the part of the
Warrant Agent, be deemed to be conclusively proved and established by an
Officers Certificate delivered to the Warrant Agent; and such Officers
Certificate shall, in the absence of bad faith on the part of the Warrant
Agent, be full authority to the Warrant Agent for any action taken, suffered or
omitted in good faith by it under the provisions of this Agreement in reliance
upon such certificate; but in its discretion the Warrant Agent may in lieu
thereof accept other evidence of such fact or matter or may require such
further or additional evidence as to it may deem reasonable.

SECTION 7.06.      Correctness of Statements. The Warrant Agent shall not be
liable for or by reason of any of the statements of fact or recitals contained
in this Agreement or in the Warrant Certificates (except its countersignature
thereof) or be required to verify the same, and all such statements and
recitals are and shall be deemed to have been made by the Company only.

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SECTION
7.07.      Validity of Agreement. The Warrant Agent shall not be under
any responsibility in respect of the validity of this Agreement or the
execution and delivery hereof (other than such execution and delivery by the
Warrant Agent) or in respect of the validity or execution of any Warrant
Certificates (except its countersignature thereof); nor shall it be responsible
for any breach by the Company of any covenant or condition contained in this
Agreement or in any Warrant Certificate; nor shall it by any act hereunder be
deemed to make any representation or warranty as to the authorization or
reservation of any shares of Common Stock to be issued pursuant to this
Agreement or any Warrants or as to whether any shares of Common Stock will,
when issued, be validly issued and fully paid and nonassessable, nor shall the
Warrant Agent be responsible for the legality of the terms hereof in its
capacity as an administrative agent.

SECTION 7.08.      Use of Agents. The 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 shall not be liable
for the acts or omissions of any such agents or attorneys appointed with due
care hereunder.

SECTION 7.09.      Liability of Warrant Agent. The Warrant Agent shall incur
no liability or responsibility to the Company or to any holder of Warrants for
any action taken in reliance on any notice, resolution, waiver, consent, order,
certificate, or other paper, document or instrument believed by it to be
genuine and to have been signed, sent or presented by the proper party or
parties. The Company agrees to indemnify the Warrant Agent and hold it
harmless against any and all
liabilities, including judgments, costs and reasonable counsel fees and
expenses, for anything done or omitted in good faith by the Warrant Agent in
the execution of this Warrant Agreement, except as a result of the Warrant
Agents gross negligence or willful misconduct or bad faith. The provisions of
this Section 7.09 shall survive the expiration of the Warrants and the
termination of this Agreement.

SECTION 7.10.      Legal Proceedings; Expenses. The Warrant Agent shall be
under no obligation to institute any action, suit or legal proceeding or to
take any other action likely to involve expense unless the Company or one or
more holders of Warrants shall furnish the Warrant Agent with security and
indemnity satisfactory to it for any costs and expenses which may be incurred,
but this provision shall not affect the power of the Warrant Agent to take such
action as the Warrant Agent may consider proper, whether with or without any
such security or indemnity.

SECTION 7.11.      Other Transactions in Securities of the Company. The
Warrant Agent in its individual or any other capacity may become the owner of
the Warrants or other securities of the Company, or become pecuniarily
interested in any transaction in which the Company may be interested, or
contract with or lend money to the Company or otherwise act as fully and freely
as though it were not Warrant Agent under this Warrant Agreement. Nothing
herein shall preclude the Warrant Agent from acting in any other capacity for
the Company, for any committee or body of holders of shares, securities or
other obligations of the Company or for any other legal entity.

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SECTION 7.12.      Actions as Agent. The Warrant Agent shall act hereunder
solely as agent and not in a ministerial capacity, and its duties shall be
determined solely by the provisions hereof, and no implied duties or
obligations shall be read into this Agreement against the Warrant Agent. The
Warrant Agent shall not be liable for anything that it may do or refrain from
doing in good faith in connection with this Agreement except for its own gross
negligence or willful misconduct or bad faith.

SECTION 7.13.      Appointment and Acceptance of Agency. The Company hereby
appoints the Warrant Agent to act as agent for the Company in respect of the
Warrants and Warrant Certificates upon the terms and conditions set forth
herein and in the Warrant Certificates. The Warrant Agent hereby accepts the
agency established by this Agreement and agrees to perform the same upon the
terms and conditions herein set forth. The Warrant Agent shall have the powers
and authority specifically granted to and conferred upon it in the Warrant
Certificates and hereby.

ARTICLE VIII

MISCELLANEOUS PROVISIONS

SECTION 8.01.      Amendments, etc.

(a)      Notwithstanding the provisions of subsection (b) below, the Warrant
Agent may, without the consent or concurrence of the registered holders of the
Warrants, enter into one or more supplemental agreements or amendments with the
Company for the purpose of evidencing the rights of Warrant holders upon any
consolidation, merger, sale, transfer, reclassification, liquidation or
dissolution pursuant to Section 4.04 hereof, making any changes or corrections
in this Agreement that are required to cure any ambiguity, to correct or
supplement any provision contained herein that may be defective or inconsistent
with any other provision herein or any clerical omission or mistake or manifest
error herein contained, or making such other provisions in regard to matters or
questions arising under this Agreement as shall not adversely affect the
interests of the holders of the Warrants or be inconsistent with this Agreement
or any supplemental agreement or amendment.

(b)      With the consent of the registered holders of at least a majority in
number of the Warrants at the time outstanding, the Company and the Warrant
Agent may at any time and from time to time by supplemental agreement or
amendment add any provisions to or change in any manner or eliminate any of the
provisions of this Agreement or of any supplemental agreement or modify in any
manner the rights and obligations of the Warrant holders and of the Company;
provided, however, that no such supplemental agreement or amendment shall,
without the consent of the registered holder of each outstanding Warrant
affected thereby, (1) alter the provisions of this Agreement so as to affect
adversely in any material respect the terms upon which the Warrants are
exercisable; or (2) reduce the number of Warrants outstanding the consent of
whose holders is required for any such supplemental agreement or amendment;
provided, further, however, that it is understood and agreed that the
provisions contained in the last sentence of Section 4.01(b) and Section
4.01(d) may be amended or waived with the

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##### 



consent of the registered holders of
at least a majority in number of the Warrants at the time outstanding.

(c)      Upon the delivery of a certificate from an appropriate officer of the
Company which states that the proposed supplement or amendment is in compliance
with the terms in this Section, the Warrant Agent shall execute such supplement
or amendment. Notwithstanding any other provision hereof, the Warrant Agents
consent must be obtained regarding any amendment or supplement pursuant to this
Section 8.01 that alters the Warrant Agents Warrants or duties.

SECTION 8.02.      Successors and Assigns. This Agreement shall be binding
upon and inure to the benefit of the parties hereto and their respective
successors and permitted assigns.

SECTION 8.03.      Notices. Any notice or demand authorized by this Agreement
to be given or made by the Warrant Agent or by the holder of any Warrant to or
on the Company shall be sufficiently given or made if sent by mail first-class,
postage prepaid or by facsimile, addressed (until another address is filed in
writing by the Company with the Warrant Agent), as follows:

| |  |                                   
| |  | ----------------------------------
| |  | IMPSAT Fiber Networks, Inc.       
| |  | Elvira Rawson de Dellepianne 150  
| |  | 11th Floor                        
| |  | C1107BCA Buenos Aires Argentina   
| |  | Attention: Chief Executive Officer
| |  | Fax: 5411-5170-3518               

Any notice or demand authorized by this Agreement shall be given or made
by the holder of any Warrant or by the Company to or on the Warrant Agent shall
be sufficiently given or made if sent by mail first class, postage prepared or
by facsimile, addressed (until another address is filed in writing by the
Warrant Agent with the Company and provided in writing to the registered
holders of the Warrants), as follows:

| |  |                                     
| |  | ------------------------------------
| |  | The Bank of New York                
| |  | 101 Barclay Street, Floor 11E       
| |  | New York, New York 10286            
| |  | Attention: Stock Transfer Department
| |  | Fax: 212-815-6979                   

Any notice of demand authorized by this Agreement to be given or made to
the holder of any Warrants shall be sufficiently given or made if sent by
first-class mail, postage prepaid to the last address of such holder as it
shall appear on the Warrant Register.

SECTION 8.04.      Applicable Law. The validity, interpretation and
performance of this Agreement and of the Warrant Certificates shall be governed
by and construed in accordance with the laws of the state of New York, without
regard to principles of conflicts of law. The parties hereto hereby waive the
right to a jury trial in

- 29 -



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##### 



any action arising out of this Agreement. Any dispute
arising out of this Agreement shall be litigated in the borough of Manhattan,
New York City, New York, and the parties hereby submit to the nonexclusive
jurisdiction of such courts and acknowledge that such courts are a convenient
forum.

SECTION 8.05.      Benefits of this Agreement.
Nothing in this Agreement expressed and nothing that may be implied from
any of the provisions hereof is intended, or shall be construed, to confer
upon, or give to, any Person other than the Company, the Warrant Agent and the
holders of the Warrants any right, remedy or claim under or by reason of this
Agreement or of any covenant, condition, stipulation, promise or agreement
hereof, and all covenants, conditions, stipulations, promises and agreements in
this Agreement contained shall be for the sole and exclusive benefit of the
Company, the Warrant Agent and their successors and assigns and of the holders
of the Warrants.

SECTION 8.06.      Registered Warrant Holders. Prior to due presentment for
registration of transfer, the Company and the Warrant Agent may deem and treat
the Person in whose name any Warrants are registered in the Warrant Register as
the absolute owner thereof for all purposes whatever (notwithstanding any
notation of ownership or other writing thereon made by anyone other than the
Company or the Warrant Agent) and neither the Company nor the Warrant Agent
shall be affected by any notice to the contrary or be bound to recognize any
equitable or other claim to or interest in any Warrants on the part of any
other Person and shall not be liable for any registration of transfer of
Warrants that are registered or to be registered in the name of a fiduciary or
the nominee of a fiduciary unless made with actual knowledge that a fiduciary
or nominee is committing a breach of trust in requesting such registration of
transfer or with such knowledge of such facts that its participation therein
amounts to bad faith. The terms Warrant holder and holder of any Warrants
and all other similar terms used herein shall mean such Person in whose name
Warrants are registered in the Warrant Register.

SECTION 8.07.      Inspection of Agreement. A copy of this Agreement shall be
available at all reasonable times for inspection by any registered Warrant
holder at the designated office of the Warrant Agent. The Warrant Agent may
require any such holder to submit his, her or its Warrant Certificate (or a
proper affidavit or other evidence satisfactory to the Warrant Agent of the
loss, theft, mutilation or destruction of such Warrant Certificate) for
inspection by it before allowing such holder to inspect a copy of this
Agreement.

SECTION 8.08.      Headings. The Article and Section headings herein are for
convenience only and are not a part of this Agreement and shall not affect the
interpretation thereof.

SECTION 8.09.      Counterparts. The Agreement may be executed in any number of
counterparts, each of which so executed shall be deemed to be an original.

- 30 -



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SIGNATURE PAGE TO
WARRANT AGREEMENT

IN WITNESS WHEREOF, this Agreement has been duly, executed by the parties
hereto as of the day and year first above written.

| |  |  |  |                             |        | 
| |  |  |  | --------------------------- | ------ | 
| |  |  |  | IMPSAT FIBER NETWORKS, INC.
| |  |  |  |                             |        | 
| |  |  |  | By:                         |        | 
| |  |  |  |                             |       
| |  |  |  |                             | Name: 
| |  |  |  |                             | Title:
| |  |  |  |                             |        | 
| |  |  |  | THE BANK OF NEW YORK       
| |  |  |  | As Warrant Agent           
| |  |  |  |                             |        | 
| |  |  |  | By:                         |        | 
| |  |  |  |                             |       
| |  |  |  |                             | Name: 
| |  |  |  |                             | Title:





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##### 



EXHIBIT A     Form of Warant Certificate

|                |  |  |  |  |  |         
|--------------- |  |  |  |  |  | --------
|No. [  
]-[   ] |  |  |  |  |  | Warrants

VOID AFTER MARCH [
     ], 2011

THE ISSUANCE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAS NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE 1933 ACT) OR
PURSUANT TO THE SECURITIES LAWS OF ANY STATE, AND SUCH SECURITIES MAY NOT BE
SOLD OR TRANSFERRED OTHER THAN IN ACCORDANCE WITH THE REGISTRATION REQUIREMENTS
OF THE 1933 ACT AND THE RULES AND REGULATIONS THEREUNDER OR AN EXEMPTION
THEREFROM AND FROM ANY APPLICABLE STATE SECURITIES LAWS.

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE THE BENEFITS OF A
REGISTRATION RIGHTS AGREEMENT DATED AS OF MARCH 25, 2003, AMONG THE COMPANY,
IMPSAT S.A., THE HOLDERS LISTED ON EXHIBIT A THERETO AND SUCH OTHER PARTIES WHO
MAY BE MADE A SIGNATORY THERETO FROM TIME TO TIME, A COPY OF WHICH IS ON FILE
WITH THE SECRETARY OF THE COMPANY.

WARRANTS TO PURCHASE COMMON STOCK
OF IMPSAT FIBER NETWORKS, INC.

IMPSAT FIBER NETWORKS, INC., a Delaware corporation (hereinafter called
the Company), for value received, hereby certifies that or registered assigns, is the owner of the number of Warrants set forth above,
each of which represents the right, at any time commencing on the Initial
Exercise Date (as such term is defined in the Warrant Agreement (as hereinafter
defined)) and before 5:00 p.m., New York time, on March [     ], 2011 on which
date such Warrants expire, initially to purchase, subject to the terms hereof
and of the Warrant Agreement (as hereinafter defined), one share of Common
Stock per Warrant, par value $.01 per share, of the Company (hereinafter called
the Common Stock) at the price of $15.00 per share (the Warrant Price),
subject to the terms and conditions hereof and of the Warrant Agreement, each
such purchase to be made, and to be deemed effective for the purpose of
determining the date of exercise, only upon surrender hereof to the Company at
the Warrant Agents Office, with the Election to Exercise Form on the reverse
hereof duly completed and signed, and upon payment in full to the Warrant Agent
for the account of the Company of the Warrant Price (a) in cash (including by
wire transfer to an account designated by the Company), (b) by certified or
official bank check, (c) by Cashless Exercise (as defined below) if otherwise
in compliance with applicable law, or (d) by any combination of the foregoing,
and upon compliance with and subject to the conditions set forth herein and in
the Warrant Agreement, including satisfaction of any necessary filing
requirements under the HSR Act. For purposes of this Warrant, a Cashless
Exercise shall mean an exercise of

- A-1 -





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##### 



a Warrant in accordance with the immediately following two sentences. To
effect a Cashless Exercise, the holder may exercise a Warrant or Warrants
without payment of the Warrant Price in cash by surrendering such Warrant or
Warrants (represented by one or more Warrant Certificates) and in exchange
therefor, receiving such number of shares of Common Stock equal to the product
of (1) that number of shares of Common Stock for which such Warrant or Warrants
are exercisable and which would be issuable in the event of an exercise with
full payment in cash of the Warrant Price and (2) the Cashless Exercise Ratio.
The Cashless Exercise Ratio shall equal a fraction, the numerator of which is
the excess of the current market price per share of Common Stock on the date of
exercise (as determined pursuant to Section 4.01(e) of the Warrant Agreement)
over the Warrant Price per share of Common Stock as of the date of exercise and
the denominator of which is the current market price per share of Common Stock
on the date of exercise (as determined pursuant to Section 4.01(e) of the
Warrant Agreement). Upon surrender of a Warrant Certificate representing more
than one Warrant in connection with the holders option to elect a Cashless
Exercise, such holder must specify the number of Warrants for which such
Warrant Certificate is to be exercised (without giving effect to the Cashless
Exercise). All provisions of the Warrant Agreement shall be applicable with
respect to a Cashless Exercise of a Warrant Certificate for less than the full
number of Warrants represented thereby. Capitalized terms that are not
otherwise defined herein shall have the meanings ascribed to them in the
Warrant Agreement.

The Warrant Price, the number of Warrant Shares and/or the number of
Warrants outstanding, are subject to adjustment in certain events as provided
in the Warrant Agreement. In the event the Company elects to adjust the number
of Warrants outstanding in substitution for any adjustment in the number of
Warrant Shares, the Company shall cause the Warrant Agent to distribute to
holders of record of Warrant Certificates either Warrant Certificates
evidencing any additional Warrants issuable pursuant to the adjustment or
substitute Warrant Certificates to replace all outstanding Warrant Certificates
in accordance with the provisions of the Warrant Agreement. The Company shall
not be required to issue fractions of Warrants or Warrant Certificates
evidencing fractional Warrants upon any such adjustment or otherwise, but the
Company shall make adjustment in cash for any fraction of a Warrant which the
registered holder of Warrants would have been entitled to receive upon such
adjustment as provided in the Warrant Agreement.

This Warrant Certificate is issued under and in accordance with the
Warrant Agreement dated as of March 25, 2003 (herein called the Warrant
Agreement), between the Company and The Bank of New York, as Warrant Agent,
and is subject to and is to be construed in accordance with the terms and
provisions of the Warrant Agreement, which terms and provisions are hereby
incorporated by reference herein and made a part hereof. Every holder of this
Warrant Certificate consents to all of the terms contained in the Warrant
Agreement by acceptance hereof. A copy of the Warrant Agreement is available
for inspection by the registered holder hereof at the office of the Warrant
Agent at the following address:

- A-2 -





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##### 



| |  |                                     
| |  | ------------------------------------
| |  | The Bank of New York                
| |  | 101 Barclay Street, Floor 11E       
| |  | New York, New York 10286            
| |  | Attention: Stock Transfer Department
| |  | Fax: 212-815-6979                   

The Company shall not be required upon the exercise of the Warrants
represented hereby to issue fractions of shares of Common Stock, to distribute
stock certificates that evidence fractional shares of Common Stock or to issue
Warrant Certificates representing fractional Warrants, but shall make
adjustment in cash for any fraction of a share as provided in the Warrant
Agreement. If the Warrants represented hereby shall be exercised in part, the
registered holder hereof shall be entitled to receive, upon surrender hereof,
another Warrant Certificate for the balance of the number of whole Warrants not
exercised as provided in the Warrant Agreement.

Commencing on the day after the Distribution Date, this Warrant
Certificate may be exchanged by any holder thereof either separately or in
combination with other Warrant Certificates at the Warrant Agents Office for
new Warrant Certificates representing the same aggregate number of Warrants
evidenced by the Warrant Certificate or Warrant Certificates exchanged, upon
surrender of this Warrant Certificate and upon compliance with and subject to
the conditions set forth herein and in the Warrant Agreement.

Commencing on the day after the Distribution Date, this Warrant
Certificate is transferable at the Warrant Agents Office by the registered
holder hereof in person or by such holders attorney duly authorized in
writing, upon surrender of this Warrant Certificate and upon compliance with
and subject to the conditions set forth herein and in the Warrant Agreement.
Upon any such transfer, a new Warrant Certificate or new Warrant Certificates
of different denominations, representing in the aggregate a like number of
Warrants, will be issued to the transferee. Every holder of Warrants, by
accepting this Warrant Certificate, consents and agrees with the Company, the
Warrant Agent and with every subsequent holder of this Warrant Certificate that
until due presentation for the registration of transfer of this Warrant
Certificate on the Warrant Register maintained by the Warrant Agent, the
Company and the Warrant Agent may deem and treat the Person in whose name this
Warrant Certificate is registered as the absolute and lawful owner for all
purposes whatsoever and neither the Company nor the Warrant Agent shall be
affected by any notice to the contrary.

The Company is authorized by the Warrant Agreement to suspend the exercise
of all Warrants for any period during which any shares of Common Stock reserved
for exercise of Warrants require, under any federal or state law or rule or
regulation of any national securities exchange or market, registration with or
approval of any governmental authority or listing on any national securities
exchange or market and such registration, approval or listing is not in effect.

- A-3 -





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##### 



Nothing contained in the Warrant Agreement or in this Warrant Certificate
shall be construed as conferring on the holder of any Warrants or such holders
transferee any rights whatsoever as a stockholder of the Company.

This Warrant Certificate shall not be valid unless countersigned by the
Warrant Agent.

The Warrant Agreement and each Warrant Certificate, including this Warrant
Certificate, shall be deemed a contract made under the laws of the State of New
York and for all purposes shall be governed by and construed in accordance with
the laws of the State of New York, without regard to principles of conflicts of
law.

IN WITNESS WHEREOF, the Company has caused this Warrant Certificate to be
duly executed under its corporate seal.

Dated:          , 2003

|                          |        |                      |                             |        | 
|------------------------- | ------ | -------------------- | --------------------------- | ------ | 
|                          |        |                      | IMPSAT FIBER NETWORKS, INC.
|                         
|[CORPORATE SEAL]          |        |                      |                             |       
|                         
|                          |        |                      | By:                         |        | 
|                          |        |                      |                             |       
|                          |        |                      |                             | Name: 
|                          |        |                      |                             | Title:
|                          |        |                      |                             |        | 
|ATTEST:                   |        |                      |                             |       
|                          |        |                      |                             |        | 
|By                        |        |                      |                             |       
|                          |        |                      |                             |        | 
|                          | Name:  |                      |                             |        | 
|                          | Title: |                      |                             |        | 
|                          |        |                      |                             |        | 
|COUNTERSIGNED             |       
|                          |        |                      | THE BANK OF NEW YORK       
|                          |        |                      | as Warrant Agent           
|                          |        |                      |                             |        | 
|Date of Countersignature: |        | By:                  |                             |       
|                          |        |                      |                             |       
|                          |        | Authorized Signatory

- A-4 -





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##### 



ELECTION TO EXERCISE

(To be executed upon exercise of Warrant)

To IMPSAT FIBER NETWORKS, INC.:

The undersigned hereby irrevocably elects to exercise      of the
Warrants represented by the within Warrant Certificate and to purchase
thereunder the shares of Common Stock issuable upon exercise of such Warrants,
as provided for therein, and tenders herewith payment of the purchase price in
full as follows: $     in the form of cash or a certified or official bank
check and the remainder of such purchase price to be paid in the form of
surrender of Warrants pursuant to a Cashless Exercise (as defined in the
Warrant Agreement) for      shares of Common Stock at the current Cashless
Exercise Ratio.

Please issue a certificate or certificates for such shares of Common Stock
in the name of, and pay any cash for any fractional share to:

|                                 |  |           |                                 | 
|-------------------------------- |  | --------- | ------------------------------- | 
|PLEASE INSERT SOCIAL SECURITY OR |  | Name:     |                                 | 
|OTHER IDENTIFYING NUMBER OF      |  |           |                                
|ASSIGNEE                         |  |           | (Please Print Name and Address)
|                                 |  | Address   |                                 | 
|                                 |  |           |                                
|                                 |  | Signature |                                 | 
|                                 |  |           |                                

| |       |  |                                                                                                                                                                                                                                                                                              | 
| | ----- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | 
| | NOTE: |  | The above signature should correspond
exactly with the name on the face of this
Warrant Certificate or with the name of
assignee appearing in the assignment form
below. In the event of any assignment, the
Warrant Agent may require evidence of payment
of any applicable transfer taxes. | 

AND, if said number of shares shall not be all the shares purchasable under the
within Warrant Certificate, a new Warrant Certificate is to be issued in the
name of said undersigned for the balance remaining of the Warrants represented
by the within Warrant Certificate less any fraction of a Warrant paid in cash.

Dated:          , 20

THE SIGNATURES) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION,
(BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH
MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO
RULE 17Ad-15 OF THE SECURITIES AND EXCHANGE COMMISSION.

- A-5 -





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##### 



ASSIGNMENT

(To be executed only upon assignment of Warrant Certificate)


For value received the Assignee named below all of the rights of the
undersigned represented by the within Warrant Certificate, with respect to the
number of Warrants set forth below:

|                 |  |         |  |                
|---------------- |  | ------- |  | ---------------
|Name of Assignee |  | Address |  | No. of Warrants
|                 |  |         |  |                
|                 |  |         |  |                
|                 |  |         |  |                
|                 |  |         |  |                

together with all right, title and interest therein, and does hereby
irrevocably constitute and appoint                attorney,
to transfer said
Warrant Certificate on the books of the within-named Company, with full power
of substitution in the premises.

Dated:            , 20

| |  |       |  |                                                                                                     
| |  | ----- |  | ----------------------------------------------------------------------------------------------------
| |  |      
| |  | NOTE: |  | The above signature should
correspond exactly with the
name on the face of this
Warrant Certificate.

Signature guaranteed:



---

THE SIGNATURES) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION,
(BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH
MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO
RULE 17Ad-15 OF THE SECURITIES AND EXCHANGE COMMISSION.

- A-6 -