Document:

<PAGE>

                                                               EXHIBIT 4.1(a)

                                 AMENDMENT NO. 1

     AMENDMENT NO. 1 dated as of September 17, 2001, between METROMEDIA FIBER
NETWORK, INC., a Delaware corporation (the "ISSUER"), each of the Guarantors
listed on the signature pages hereto under the caption "GUARANTORS" (each a
"GUARANTOR" and, collectively, the "GUARANTORS", and the Guarantors collectively
with the Issuer, the "OBLIGORS"), each of the purchasers whose names appear on
the signature pages hereto under the caption "PURCHASERS" (each a "PURCHASER"
and, collectively, the "PURCHASERS") and Citicorp USA, Inc., as administrative
agent (in such capacity, together with its successors in such capacity, the
"ADMINISTRATIVE AGENT").

     The Issuer, the Guarantors, the Purchasers and the Administrative Agent are
parties to a Note and Guarantee Agreement dated as of September 6, 2001
providing, subject to the terms and conditions thereof, for the purchase of
notes in an aggregate principal amount equal to $150,000,000. The parties hereto
wish to amend the Note and Guarantee Agreement in certain respects and,
accordingly, hereby agree as follows:

     Section 1. DEFINITIONS. Except as otherwise defined in this Amendment No.
1, terms defined in the Note and Guarantee Agreement are used herein as defined
therein.

     Section 2. AMENDMENTS. Subject to the execution and delivery hereof by each
of the parties hereto, the Note and Guarantee Agreement shall be amended as
follows:

          2.01. References in the Note and Guarantee Agreement (including
     references to the Note and Guarantee Agreement as amended hereby) to "this
     Agreement" (and indirect references such as "hereunder", "hereby", "herein"
     and "hereof") shall be deemed to be references to the Note and Guarantee
     Agreement as amended hereby.

          2.02. EXTENSION OF CLOSING DATE DEADLINE. Section 2.04(f) of the Note
     and Guarantee Agreement shall be amended by deleting the date "September
     17, 2001" therein and inserting "October 1, 2001" in lieu thereof.

<PAGE>

          2.03. CERTAIN ADDITIONAL CONDITIONS. Section 3.01(r) of the Note and
     Guarantee Agreement is hereby relettered as Section 3.01(s) and a new
     Section 3.01(r) is hereby inserted into the Note and Guarantee Agreement to
     read as follows:

               "(r) CERTAIN ADDITIONAL CONDITIONS. Evidence satisfactory to the
          Purchasers that:

                    (i) without limiting the generality of the representation
               and warranty set forth in Section 4.01(g) which, pursuant to
               clause (i) of the last paragraph of this Section 3.01 must be
               true and correct as a condition to the purchase of Notes
               hereunder, the destruction of the World Trade Center on September
               11, 2001, and the collapse of neighboring buildings and market
               disruptions as a consequence thereof (and any damage that may
               have been caused to fiberoptic networks of the Borrower and its
               Restricted Subsidiaries in that area) will not result in a
               material adverse effect on the business, assets, results of
               operations, financial condition or liabilities of the Borrower
               and its Restricted Subsidiaries and

                    (ii) subsequent to the date hereof (i.e. September 6, 2001)
               no adverse change in financial, banking or capital market
               conditions has occurred that, in the judgment of each Purchaser,
               could materially impair the ultimate syndication or distribution
               of the Commitments or Notes issued under this Agreement or
               otherwise render the purchase of the Notes inadvisable."

     Section 3. MISCELLANEOUS. Except as herein provided, the Note and Guarantee
Agreement shall remain unchanged and in full force and effect (and, without
limiting the generality of the foregoing, nothing herein shall be deemed a
waiver of the condition set forth in Section 3.01(k) of the Note and Guarantee
Agreement, the parties hereto hereby acknowledging that the due diligence
investigation by the Purchasers of the Issuer and its Subsidiaries referred to
therein has not been completed). This Amendment No. 1 may be executed in any
number of counterparts, all of which taken together shall constitute one and the
same amendatory instrument and any of the parties hereto may execute this
Amendment No. 1 by signing any such counterpart. This Amendment No. 1 shall be
governed by, and construed in accordance with, the law of the State of New York.

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 1 to
be duly executed and delivered as of the day and year first above written.

                                             METROMEDIA FIBER NETWORK, INC.

                                             By: /s/ Nick Tanzi
                                                 -------------------------------
                                                 Name: Nick Tanzi
                                                 Title: President & CEO

                              GUARANTORS

METROMEDIA FIBER NETWORK                     METROMEDIA FIBER NATIONAL
   SERVICES, INC.                               NETWORK, INC.

By: /s/ Nick Tanzi                           By: /s/ Nick Tanzi
    -------------------------------              -------------------------------
    Name: Nick Tanzi                             Name: Nick Tanzi
    Title: President & CEO                       Title: President & CEO

ABOVENET COMMUNICATIONS INC.                 PAIX.NET, INC.

By: /s/ Nick Tanzi                           By: /s/ Nick Tanzi
    -------------------------------              -------------------------------
    Name: Nick Tanzi                             Name: Nick Tanzi
    Title: President & CEO                       Title: President & CEO

METROMEDIA FIBER NETWORK                     SITESMITH INC.
  OF NEW JERSEY, INC.

By: /s/ Nick Tanzi                           By: /s/ Nick Tanzi
    -------------------------------              -------------------------------
    Name: Nick Tanzi                             Name: Nick Tanzi
    Title: President & CEO                       Title: President & CEO

<PAGE>

MFN OF UTAH L.L.C.                           MFN OF VA, L.L.C.

By: /s/ Nick Tanzi                           By: /s/ Nick Tanzi
    -------------------------------              -------------------------------
    Name: Nick Tanzi                             Name: Nick Tanzi
    Title: President & CEO                       Title: President & CEO

METROMEDIA FIBER NETWORK                     METROMEDIA FIBER NETWORK
   OF ILLINIOS, INC.                            INTERNATIONAL, INC.

By: /s/ Nick Tanzi                           By: /s/ Nick Tanzi
    -------------------------------              -------------------------------
    Name: Nick Tanzi                             Name: Nick Tanzi
    Title: President & CEO                       Title: President & CEO

MFN EUROPE FINANCE, INC                      MFN INTERNATIONAL, L.L.C.

By: /s/ Nick Tanzi                           By: /s/ Nick Tanzi
    -------------------------------              -------------------------------
    Name: Nick Tanzi                             Name: Nick Tanzi
    Title: President & CEO                       Title: President & CEO

MFN JAPAN BACKHAUL, INC.                      MFN PURCHASING, INC.

By: /s/ Nick Tanzi                           By: /s/ Nick Tanzi
    -------------------------------              -------------------------------
    Name: Nick Tanzi                             Name: Nick Tanzi
    Title: President & CEO                       Title: President & CEO

                                             THE ADMINISTRATIVE AGENT

                                             CITICORP, USA, INC., as
                                             Administrative Agent

                                             By: /s/ Richard Zagheb
                                                 -------------------------------
                                                 Name: Richard Zagheb
                                                 Title: Vice President

<PAGE>

                                             PURCHASERS

                                             CITIBANK USA, INC.

                                             By: /s/ Richard Zagheb
                                                -------------------------------
                                                Name: Richard Zagheb
                                                Title: Vice President

                                             MERRILL LYNCH GLOBAL
                                               ALLOCATION FUND, INC.

                                             By: /s/ Lisa Ann O'Donnell
                                                 -------------------------------
                                                 Lisa Ann O'Donnell
                                                 Director, Merrill Lynch
                                                   Investment Managers
                                                 Authorized Signatory

                                             MERRILL LYNCH EQUITY/CONVERTIBLE
                                               SERIES GLOBAL ALLOCATION
                                               PORTFOLIO

                                             By: /s/ Lisa Ann O'Donnell
                                                 -------------------------------
                                                 Lisa Ann O'Donnell
                                                 Director, Merrill Lynch
                                                   Investment Managers
                                                 Authorized Signatory

                                             MERRILL LYNCH VARIABLE SERIES
                                               FUNDS, INC. (MERRILL LYNCH GLOBAL
                                               ALLOCATION FOCUS FUND)

                                             By: /s/ Bryan N. Ison
                                                 -------------------------------
                                                 Bryan N. Ison
                                                 First Vice President, Merrill
                                                   Lynch Investment Managers
                                                 Authorized Signatory

<PAGE>

                                             MERRILL LYNCH SERIES FUND, INC.
                                               (GLOBAL ALLOCATION STRATEGY
                                               PORTFOLIO)

                                             By: /s/ Lisa Ann O'Donnell
                                                 -------------------------------
                                                 Lisa Ann O'Donnell
                                                 Director, Merrill Lynch
                                                    Investment Managers
                                                 Authorized Signatory

                                             JOHN W. KLUGE, CHASE MANHATTAN
                                               BANK AND STUART SUBOTNICK,
                                               TRUSTEES UNDER A TRUST
                                               AGREEMENT BETWEEN JOHN W KLUGE,
                                               AS GRANTOR AND JOHN W. KLUGE AND
                                               MANUFACTURERS HANOVER TRUST
                                               COMPANY, AS TRUSTEES, DATED MAY
                                               30, 1984, AS AMENDED AND RESTATED

                                             By: /s/ Stuart Subotnick
                                                -------------------------------
                                                Name:  Stuart Subotnick
                                                Title: Trustee<Page>

                                                                 Exhibit 4.1(b)

                                                                Execution Copy

                                 AMENDMENT NO. 2

       AMENDMENT NO. 2 dated as of October 1, 2001, between METROMEDIA FIBER
NETWORK, INC., a Delaware corporation (the "ISSUER"), each of the Guarantors
listed on the signature pages hereto under the caption "GUARANTORS" (each a
"GUARANTOR" and, collectively, the "GUARANTORS", and the Guarantors collectively
with the Issuer, the "OBLIGORS"), each of the purchasers whose names appear on
the signature pages hereto under the caption "PURCHASERS" (each a "PURCHASER"
and, collectively, the "PURCHASERS") and Citicorp USA, Inc., as administrative
agent (in such capacity, together with its successors in such capacity, the
"ADMINISTRATIVE AGENT").

       The Issuer, the Guarantors, the Purchasers and the Administrative Agent
are parties to a Note and Guarantee Agreement dated as of September 6, 2001 (as
heretofore amended, the "NOTE AND GUARANTEE AGREEMENT") providing, subject to
the terms and conditions thereof, for the purchase of notes in an aggregate
principal amount equal to $150,000,000. The parties hereto wish to amend the
Note and Guarantee Agreement in certain respects and, accordingly, hereby agree
as follows:

       Section 1. DEFINITIONS. Except as otherwise defined in this Amendment No.
2, terms defined in the Note and Guarantee Agreement are used herein as defined
therein.

       Section 2. AMENDMENTS. Subject to the execution and delivery hereof by
each of the parties hereto, the Note and Guarantee Agreement shall be amended as
follows:

       2.01. References in the Note and Guarantee Agreement (including
references to the Note and Guarantee Agreement as amended hereby) to "this
Agreement" (and indirect references such as "hereunder", "hereby", "herein" and
"hereof") shall be deemed to be references to the Note and Guarantee Agreement
as amended hereby.

       2.02. DEFINITIONS. The following definitions (to the extent already in
Section 1.01 of the Note and Guarantee Agreement) are hereby amended in their
entirety and (to the extent not already in Section 1.01 of the Note and
Guarantee Agreement) are hereby inserted in said Section 1.01 in the appropriate
alphabetical location as follows:

              "APPLICABLE MARGIN" means, for any day, (i) 4.50% with respect to
       any Base Rate Portions and (ii) 5.50% with respect to any Eurodollar Rate
       Portions, PROVIDED that at all times after December 31, 2005, the
       Applicable Margin shall be (iii) 6.50% with respect to any Base Rate
       Portions and (ii) 7.50% with respect to any Eurodollar Rate Portions.

              "DEFAULT" means any Event of Default and any event that would
       constitute an Event of Default but for the requirement that notice be
       given or time elapse or both.

              "MATERIAL AGREEMENT" means, collectively, (a) the Senior Notes and
       the Subordinated Notes (and any indenture relating thereto), (b) the
       Nortel Agreement and the other Vendor Agreements, (c) the Verizon
       Agreement and Verizon Debt Agreement, (d) any agreement with a vendor or
       contractor pursuant to which the Issuer reasonably anticipates that the
       Issuer and its Subsidiaries will purchase in the aggregate more than
       $50,000,000 of equipment or

<Page>
                                      -2-

       construction services, (e) any agreement providing for the sale or lease
       of fiber or internet infrastructure services by the Issuer or any
       Restricted Subsidiary for aggregate consideration of $50,000,000 or more,
       (f) the agreements and instruments entered into pursuant to Section
       3.01(l) and (g) the other agreements listed in Schedule 4.01(k).

              "SENIOR SECURITY DOCUMENTS" means (a) the Junior Intercreditor and
       Collateral Agency Agreement, (b) the Verizon Intercreditor Agreement, (c)
       the Senior Security Agreement, (d) the Senior Mortgages and (e) each
       other security agreement, pledge agreement, mortgage, deed of trust,
       assignment agreement and other instrument (including any Uniform
       Commercial Code financing statements) being executed concurrently
       herewith or from time to time hereafter providing for the grant of liens
       and security interests (or the recordation thereof) by any of the
       Obligors in favor of the Administrative Agent on property of the Obligors
       as collateral security for any of the obligations of the Obligors
       hereunder.

              "SUBORDINATED NOTES" means (i) the $300,000,000 6.15% Series A
       Convertible Subordinated Notes due 2010 and (ii) the $675,281,000 6.15%
       Series B Convertible Subordinated Notes due 2010, both issued by the
       Issuer pursuant to an Indenture dated as of October 1, 2001.

              "VERIZON AGREEMENT" means the Fiber Optics Private Network
       Agreement dated as of October 7, 1999 between Verizon Global Networks
       Inc. (formerly known as Bell Atlantic Global Networks, Inc.) and
       Metromedia Fiber Network Services, Inc., as the same has been amended
       pursuant to (a) a letter agreement dated June 20, 2000 between the
       Issuer, Metromedia Fiber Network Services, Inc. and Verizon Global
       Networks Inc. under which a portion of the Contract Minimum under said
       Fiber Optics Private Network Agreement is allocated to and assumed by
       Genuity Network Inc., (b) by Amendment No. 1 thereto and (c) an Amendment
       No. 2 thereto to be executed and delivered on the Closing Date as
       contemplated by the last sentence of Section 3.01(m). References in this
       Agreement to the "Verizon Agreement" shall refer to said Fiber Optics
       Private Network Agreement as so allocated between Verizon Global Networks
       Inc. and Genuity Networks, Inc.

              "VERIZON INDENTURE" has the meaning specified in the Verizon
       Intercreditor Agreement.

              "VERIZON INTERCREDITOR AGREEMENT" means the Intercreditor
       Agreement dated as of October 1, 2001 between the Issuer, the
       Administrative Agent and Wilmington Trust Company, as trustee for the
       Verizon Noteholders referred to therein, which Intercreditor Agreement is
       executed pursuant to the requirements of Section 3.01(m).

       Section 2.03. DEFINITION OF "NET AVAILABLE PROCEEDS". Clause (a)(2) of
the definition of "Net Available Proceeds" in Section 1.01 of the Note and
Guarantee Agreement is hereby amended in its entirety to read as follows:

              "(2) such Net Available Proceeds shall be net of any repayments of
       Indebtedness by the Issuer and its Restricted Subsidiaries to the extent
       that such Indebtedness is secured by a Lien (other than a Lien under, or
       subject to the provisions of, the Junior Security Documents) on the
       property that is the subject of such Asset Sale and, in the case of any
       sale of allocated capacity on the Japan-US Cable Network, net of any
       amounts required under Section 5.24 of the

<Page>
                                      -3-

       Verizon Indenture (as the Verizon Indenture is in effect on the Closing
       Date and without giving effect to any modifications or supplements
       thereto after the Closing Date) to be deposited into the Disbursement
       Account under and as defined in the Verizon Intercreditor Agreement; and"

       Section 2.04. INTEREST RATE. A new paragraph is hereby inserted at the
end of Section 2.05(a) of the Note and Guarantee Agreement to read as follows:

              "Notwithstanding the foregoing, in no event shall the rate of
       interest in respect of the Base Rate Portion or Eurodollar Portion of any
       Note at any time be less than 8.00% per annum."

       Section 2.05. VERIZON DEBT AGREEMENT. Section 3.01(m) of the Note and
Guarantee Agreement is hereby amended in its entirety to read as follows:

              "(m) VERIZON DEBT AGREEMENT. Evidence that the Issuer shall have
       received net cash proceeds in an amount at least equal to $50,000,000
       from the issuance at par of secured Indebtedness, pursuant to agreements
       (including all related shareholder, registration right and other
       agreements) in form and substance satisfactory to the Purchasers, with
       the terms and conditions applicable to such Indebtedness being
       satisfactory in form and substance to each purchaser, it being understood
       that such Indebtedness shall be incurred by the Issuer to finance the
       monetary obligations due under the C&MA in connection with the Phase II
       Upgrade, including to the extent specifically set forth on Schedule I
       attached to the Depositary Agreement or to pay Network O&M Costs and
       after the occurrence of the Phase II RFS Date, to finance Network O&M
       Costs or to finance all or part of the cost of the engineering,
       construction, installation, acquisition, lease, development or
       improvement of Telecommunications Assets and shall be secured by all of
       the Issuer's right, title and interest in the Japan-US Cable Network and
       related assets and that, in connection therewith, Verizon, Inc. (or the
       respective affiliate party thereto) shall have entered into intercreditor
       arrangements satisfactory to the Administrative Agent with respect to the
       Japan-US Cable Network and such related assets. In addition, to the
       extent that the Verizon Agreement shall be modified or supplemented in
       connection with the execution and delivery of the Verizon Debt Agreement,
       each Purchaser shall have received a copy of such modification or
       supplement and such modification or supplement shall be satisfactory in
       form and substance to each Purchaser."

       Section 2.06. CERTAIN INDEBTEDNESS. Sections 6.01(a)(ii) and 6.01(b)(ii)
of the Note and Guarantee Agreement are hereby amended in their entirety to read
as follows:

              "(a)(ii) existing Indebtedness of the Issuer as listed on a
       schedule to be prepared on or before the Closing Date, the contents of
       which schedule shall be in form and substance satisfactory to each
       Purchaser;

              "(b)(ii) existing Indebtedness of the Restricted Subsidiaries as
       listed on a schedule to be prepared on or before the Closing Date, the
       contents of which schedule shall be in form and substance satisfactory to
       each Purchaser."

<Page>
                                      -4-

       Section 2.07. CERTAIN LIENS. Clauses (d) and (h) of Section 6.02 of the
Note and Guarantee Agreement are hereby amended in their entirety to read as
follows:

              "(d) carriers', warehousemen's, mechanics', materialmen's,
       repairmen's or other like Liens arising in the ordinary course of
       business that are not overdue for a period of more than 30 days or that
       are being contested in good faith and by appropriate proceedings so long
       as the aggregate amount of all such Liens shall not at any time exceed
       the sum of (i) $5,000,000 PLUS (ii) with respect to any such Liens
       outstanding on the Closing Date (but not any such Liens arising after the
       Closing Date), an additional $2,100,000

              (h) Liens securing Indebtedness permitted under Section 6.01(a)(v)
       and (ix) and 6.01(b)(iv), so long as (i) in the case of Sections
       6.01(a)(v) and 6.01(b)(iv), such Liens cover only the assets engineered,
       constructed, installed, acquired, developed or improved with such
       Indebtedness and (ii) in the case of Section 6.01(a)(ix), such Liens
       cover only property constituting "Verizon Collateral" in accordance with
       the requirements of the Verizon Intercreditor Agreement;".

       Section 2.08. INVESTMENTS. Clauses (ii) and (iv) of Section 6.05(a) of
the Note and Guarantee Agreement are hereby amended in their entirety to read as
follows:

              "(ii) cash and Cash Equivalents, PROVIDED that all such cash and
       Cash Equivalents of the Obligors (other than (A) up to $1,000,000 that
       may be held in operating deposit accounts, (B) up to $2,200,000 that may
       be pledged to secure obligations in respect of letters of credit issued
       by The Chase Manhattan Bank, (C) up to $9,720,000 that may be pledged to
       secure obligations in respect of letters of credit issued by Citibank,
       N.A. (or by affiliates of Citibank, N.A.), (D) up to $2,000,000 that may
       be pledged to secure obligations in respect of letters of credit issued
       by Silicon Valley Bank and (E) the balance from time to time standing to
       the credit of the Verizon Disbursement Account under and as define in the
       Verizon Intercreditor Agreement) is held in the Collateral Accounts under
       and as defined in the Senior Security Agreement);

              (iv) Investments by the Obligors in Metromedia Fiber Network
       (Bermuda) Ltd., a Bermuda company and a Wholly Owned Restricted
       Subsidiary, required under the consortium arrangements for the undersea
       cables of TAT-14 and APCN-2 of which Metromedia Fiber Network (Bermuda)
       Ltd. is a member, in an aggregate amount (x) not to exceed $28,000,000
       during the period commencing on the date hereof through and including
       December 31, 2001 and (y) not to exceed $38,000,000 during the period
       commencing on the date hereof through and including December 31, 2002;".

       Section 2.09. SALES OF ASSETS. A new paragraph is hereby inserted at the
end of Section 6.06(a) of the Note and Guarantee Agreement to read as follows:

              "Notwithstanding the foregoing, the Issuer will not, and will not
       permit any of its Subsidiaries to, sell any ownership interest in any
       allocated capacity in respect of the Japan-US Cable Network if the same
       would require that the Issuer make an offer to purchase the notes issued
       under the Verizon Debt Agreement pursuant to Section 5.24 of the Verizon
       Indenture (as the Verizon Indenture is in effect on the Closing Date and
       without giving effect to any modifications or supplements thereto after
       the Closing Date)."

<Page>
                                      -5-

       Section 2.10. MODIFICATIONS TO CERTAIN AGREEMENTS. Section 6.12 of the
Note and Guarantee Agreement is hereby amended in its entirety to read as
follows:

              "Section 6.12. MODIFICATIONS TO CERTAIN AGREEMENTS. None of the
       Obligors will, nor will it cause or permit any Restricted Subsidiary to
       permit any waiver, supplement, modification, amendment, termination or
       release of (i) the Senior Notes or the Subordinated Notes (or any
       indenture relating thereto), (ii) the Nortel Agreement, (iii) the Verizon
       Debt Agreement and the Verizon Agreement, if, in the case of any
       modification to the Verizon Agreement, the same would result in (or would
       reasonably be expected to result in) the reduction of the aggregate
       amounts payable under the Verizon Agreement to the Issuer and its
       Restricted Subsidiaries during calendar years 2001 and 2002 by more than
       10% in either of such years, (iv) the agreements referred to in Section
       3.01(l) hereto pursuant to which the Issuer is to issue unsecured
       convertible debt or equity under the conditions set forth in such Section
       3.01(l) or (v) any other Material Agreement, or its articles, charter or
       by-laws, in each case to the extent that any such waiver, supplement,
       modification, amendment, termination or release under this clause (v)
       could reasonably be expected (individually or in the aggregate) to have a
       Material Adverse Effect. Without limiting the generality of the
       foregoing, the Issuer will not issue any shares of Disqualified Stock."

       Section 2.11. REFERENCES TO CITIBANK USA. The references on the signature
page of the Note and Guarantee Agreement and in Schedule I thereto to "Citibank
USA" are deleted and "Citicorp USA" inserted in lieu thereof.

       Section 2.12. SCHEDULES. Schedules 4.01(k) and 4.01(v) to the Note and
Guarantee Agreement shall be amended to read in their entirety as set forth in
Schedules 4.01(k) and 4.01(v) hereto.

       Section 3. CONSENT TO AMENDMENT TO NORTEL AGREEMENT. The Purchasers
hereby consent to an amendment to the Nortel Agreement in substantially the form
of Exhibit A hereto.

       Section 4. SCHEDULES. The Purchasers hereby confirm that Schedules
4.01(j) [Litigation], 6.01 [Existing Indebtedness], 6.02 [Liens] and 6.08
[Restrictive Agreements], set forth on Exhibits A through D respectively, are in
form and substance satisfactory to each Purchaser for purposes of Sections
4.01(j), 6.01(a)(ii), 6.01(b)(ii), 6.02(b) and 6.08(i).

       Section 5. MISCELLANEOUS. Except as herein provided, the Note and
Guarantee Agreement shall remain unchanged and in full force and effect. This
Amendment No. 2 may be executed in any number of counterparts, all of which
taken together shall constitute one and the same amendatory instrument and any
of the parties hereto may execute this Amendment No. 2 by signing any such
counterpart. This Amendment No. 2 shall be governed by, and construed in
accordance with, the law of the State of New York.

<Page>
                                      -6-

       IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 2
to be duly executed and delivered as of the day and year first above written.

                                         METROMEDIA FIBER NETWORK, INC.

                                         By /s/ Nick Tanzi
                                            ---------------------------------
                                            Name:  Nick Tanzi
                                            Title: President and CEO

                                   GUARANTORS

METROMEDIA FIBER NETWORK                 METROMEDIA FIBER NATIONAL
   SERVICES, INC.                          NETWORK, INC.

By /s/ Nick Tanzi                           By /s/ Nick Tanzi
   ---------------------------------        ---------------------------------
   Name:  Nick Tanzi                        Name:  Nick Tanzi
   Title: President and CEO                 Title: President and CEO

ABOVENET COMMUNICATIONS INC.             PAIX.NET, INC.

By /s/ Nick Tanzi                           By /s/ Nick Tanzi
   ---------------------------------        ---------------------------------
   Name:  Nick Tanzi                        Name:  Nick Tanzi
   Title: President and CEO                 Title: President and CEO

METROMEDIA FIBER NETWORK                 SITESMITH INC.
  OF NEW JERSEY, INC.

By /s/ Nick Tanzi                           By /s/ Nick Tanzi
   ---------------------------------        ---------------------------------
   Name:  Nick Tanzi                        Name:  Nick Tanzi
   Title: President and CEO                 Title: President and CEO

<Page>
                                      -7-

MFN OF UTAH L.L.C.                       MFN OF VA, L.L.C.

By /s/ Nick Tanzi                           By /s/ Nick Tanzi
   ---------------------------------        ---------------------------------
   Name:  Nick Tanzi                        Name:  Nick Tanzi
   Title: President and CEO                 Title: President and CEO

METROMEDIA FIBER NETWORK                 METROMEDIA FIBER NETWORK
   OF ILLINIOS, INC.                       INTERNATIONAL, INC.

By /s/ Nick Tanzi                           By /s/ Nick Tanzi
   ---------------------------------        ---------------------------------
   Name:  Nick Tanzi                        Name:  Nick Tanzi
   Title: President and CEO                 Title: President and CEO

MFN EUROPE FINANCE, INC                  MFN INTERNATIONAL, L.L.C.

By /s/ Nick Tanzi                           By /s/ Nick Tanzi
   ---------------------------------        ---------------------------------
   Name:  Nick Tanzi                        Name:  Nick Tanzi
   Title: President and CEO                 Title: President and CEO

MFN JAPAN BACKHAUL, INC.                 MFN PURCHASING, INC.

By /s/ Nick Tanzi                           By /s/ Nick Tanzi
   ---------------------------------        ---------------------------------
   Name:  Nick Tanzi                        Name:  Nick Tanzi
   Title: President and CEO                 Title: President and CEO

                                         THE ADMINISTRATIVE AGENT

                                         CITICORP USA, INC., as Administrative
                                           Agent

                                         By /s/ Caesar W. Wyszomirski
                                            ---------------------------------
                                            Name:  Caesar W. Wyszomirski
                                            Title: Vice-President

<Page>
                                      -8-

                                         PURCHASERS

                                         CITICORP USA, INC.

                                         By /s/ Caesar W. Wyszomirski
                                            ---------------------------------
                                            Name:  Caesar W. Wyszomirski
                                            Title: Vice-President

<Page>
                                      -9-

                                         MERRILL LYNCH GLOBAL
                                           ALLOCATION FUND, INC.

                                         By /s/ Lisa Ann O'Donnell
                                            ---------------------------------
                                            Lisa Ann O'Donnell
                                            Director, Merrill Lynch Investment
                                              Managers
                                            Authorized Signatory

                                         MERRILL LYNCH EQUITY/CONVERTIBLE
                                           SERIES GLOBAL ALLOCATION
                                           PORTFOLIO

                                         By /s/ Lisa Ann O'Donnell
                                            ---------------------------------
                                            Lisa Ann O'Donnell
                                            Director, Merrill Lynch Investment
                                              Managers
                                            Authorized Signatory

                                         MERRILL LYNCH VARIABLE SERIES
                                           FUNDS, INC. (MERRILL LYNCH GLOBAL
                                           ALLOCATION FOCUS FUND)

                                         By /s/ Merrill Lynch
                                            ---------------------------------
                                                              , Merrill Lynch
                                            Investment
                                            Managers
                                            Authorized Signatory

                                         MERRILL LYNCH SERIES FUND, INC.
                                           (GLOBAL ALLOCATION STRATEGY
                                           PORTFOLIO)

                                         By /s/ Lisa Ann O'Donnell
                                            ---------------------------------
                                            Lisa Ann O'Donnell
                                            Director, Merrill Lynch Investment
                                              Managers
                                            Authorized Signatory

<Page>
                                      -10-

                                         JOHN W. KLUGE, CHASE MANHATTAN
                                           BANK AND STUART SUBOTNICK,
                                           TRUSTEES UNDER A TRUST
                                           AGREEMENT BETWEEN JOHN W KLUGE,
                                           AS GRANTOR AND JOHN W. KLUGE AND
                                           MANUFACTURERS HANOVER TRUST
                                           COMPANY, AS TRUSTEES, DATED MAY
                                           30, 1984, AS AMENDED AND RESTATED

                                         By /s/ Stuart Subotnick
                                            ---------------------------------
                                            Name:  Stuart Subotnick
                                            Title: Trustee

<Page>

                           AMENDMENT TO NOTE AGREEMENT

       This AMENDMENT TO NOTE AGREEMENT (this "AMENDMENT") is made and entered
into effective as of September 28, 2001, by and among METROMEDIA FIBER NETWORK
SERVICES, INC. (the "ISSUER"), a Delaware corporation, each of the purchasers
which is a party hereto (as evidenced by the signature pages of this Agreement)
or which may from time to time become a party to the Note Agreement as a
purchaser or any successor or assignee thereof (individually, a "PURCHASER" and,
collectively, the "PURCHASERS"), and NORTEL NETWORKS INC., a Delaware
corporation, as administrative agent for itself and the other Purchasers (in
such capacity, together with its successors in such capacity, the
"ADMINISTRATIVE AGENT").

                                    RECITALS:

       A. Pursuant to that certain Note Agreement dated as of September 19,
2001, by and among the Issuer, the Purchasers and the Administrative Agent (as
amended, the "Note Agreement"), the Purchasers agreed to purchase notes issued
by the Issuer in the aggregate principal amount of $231,036,842.

       B. The parties hereto desire to amend the Note Agreement in certain
respects.

                                   AGREEMENTS:

       NOW, THEREFORE, in consideration of the premises and mutual covenants and
agreements contained herein and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereto
hereby agree as follows:

       1. TERMS DEFINED. Unless otherwise defined or stated in this Amendment,
each capitalized term used in this Amendment has the meaning given to such term
in the Note Agreement (as amended by this Amendment).

       2. AMENDMENT TO SECTION 1.01.

       (a) The following definitions set forth in Section 1.01 of the Note
Agreement are hereby amended and restated to read in their entirety as follows:

              "`HOLDINGS SUBORDINATED NOTES' means (a) the $972,281,000 6.15%
       Convertible Subordinated Notes due 2010 issued by Holdings pursuant to an
       indenture dated as of March 6, 2000 and (b) (i) the $300,000,000 6.15%
       Series A Convertible Subordinated Notes due 2010 and (ii) the
       $675,281,000 6.15% Series B Convertible Subordinated Notes due 2010, both
       issued by Holdings pursuant to an Indenture dated as of September 28,
       2001."

              "`MATERIAL AGREEMENT' means, collectively, (a) the Holdings Senior
       Notes and the Holdings Subordinated Notes (and any indenture relating
       thereto), (b) the Note

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                                      -2-

       Documents, (c) the Vendor Agreements, (d) the Verizon Agreement and the
       Verizon Debt Agreement, (e) any agreement with a vendor or contractor
       pursuant to which Holdings reasonably anticipates that Holdings and its
       Subsidiaries will purchase in the aggregate more than $50,000,000 of
       equipment or construction services, (f) any agreement providing for the
       sale or lease of fiber by Holdings or any Restricted Subsidiary for
       aggregate consideration of $50,000,000 or more, (g) the Holdings
       Convertible Debt or Equity Documents, (h) the Holdings Notes Documents,
       (i) the agreements and instruments entered into pursuant to Section 3.01,
       and (j) the other agreements listed in Schedule 4.01(k)."

       (b) Clause (a)(ii) of the definition of "Net Available Proceeds" in
Section 1.01 of the Note Agreement is hereby amended and restated to read in its
entirety as follows:

              "(ii) such Net Available Proceeds shall be net of any repayments
       of Indebtedness by Holdings and its Restricted Subsidiaries to the extent
       that such Indebtedness is secured by a Lien (other than a Lien under, or
       subject to the provisions of, the Junior Security Documents) on the
       property that is the subject of such Asset Sale and, in the case of any
       sale of allocated capacity on the Japan-US Cable Network, net of any
       amounts required under Section 5.24 of the Verizon Indenture (as the
       Verizon Indenture is in effect on the Closing Date and without giving
       effect to any modifications or supplements thereto after the Closing
       Date) to be deposited into the Disbursement Account under and as defined
       in the Verizon Intercreditor Agreement; and"

       3. ADDITIONAL AMENDMENT TO SECTION 1.01. The following definitions are
hereby added to Section 1.01 of the Note Agreement to read in their entirety as
follows, which definitions shall appear in alphabetical order in Section 1.01:

              "'VERIZON INDENTURE' has the meaning specified in the Holdings
       Notes Agreement."

              "'VERIZON INTERCREDITOR AGREEMENT' has the meaning specified in
       the Holdings Notes Agreement."

         4. AMENDMENT TO SECTION 2.03. The reference to the date "September 28,
2001" contained in Section 2.03(e) of the Note Agreement is hereby amended to
mean and refer to the date "October 1, 2001".

       5. AMENDMENT TO SECTION 3.01(K). Section 3.01(k) of the Note Agreement is
hereby amended and restated to read in its entirety as follows:

              "(k) VERIZON DEBT AGREEMENT. Evidence that Holdings shall have
       received net cash proceeds in an amount at least equal to $50,000,000
       from the issuance at par of secured Indebtedness, pursuant to agreements
       (including all related shareholder, registration right and other
       agreements) in form and substance satisfactory to the Purchasers, with
       the terms and conditions applicable to such Indebtedness being
       satisfactory in form and substance to each Purchaser, it being understood
       that such
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                                      -3-

       Indebtedness shall be incurred by Holdings to finance the monetary
       obligations referred to in Section 3.01(m) of the Holdings Notes
       Agreement and shall be secured by the Japan-US Cable Network and related
       assets and that, in connection therewith, Verizon, Inc. (or the
       respective affiliate party thereto) shall have entered into intercreditor
       arrangements satisfactory to the Holdings Notes Agent with respect to the
       Japan-US Cable Network and such related assets. In addition, to the
       extent that the Verizon Agreement shall be modified or supplemented in
       connection with the execution and delivery of the Verizon Debt Agreement,
       each Purchaser shall have received a copy of such modification or
       supplement and such modification or supplement shall be satisfactory in
       form and substance to each Purchaser."

       6. AMENDMENT TO SECTION 4.01(J). CLAUSE (I) of SECTION 4.01(J) of the
Note Agreement is hereby amended and restated to read in its entirety as
follows:

              "(i) LITIGATION. Other than as set forth on Schedule 4.01(j)
       hereto, there are no actions, suits or proceedings at law or in equity or
       by or before any Governmental Authority now pending or, to the knowledge
       of any Obligor, threatened against or affecting Holdings or any
       Restricted Subsidiary or any business, property or rights of Holdings or
       any Restricted Subsidiary (A) that involve any Basic Document or the
       Transactions or (B) as to which there is a reasonable likelihood of an
       adverse determination and that, if adversely determined, individually or
       in the aggregate, has had or could reasonably be expected (individually
       or in the aggregate) to have a Material Adverse Effect."

       7. AMENDMENT TO SECTION 6.01(A). CLAUSE (II) of SECTION 6.01(A) of the
Note Agreement is hereby amended and restated to read in its entirety as
follows:

              "(ii) existing Indebtedness of Holdings as listed on SCHEDULE 6.01
       hereto;"

       8. AMENDMENT TO SECTION 6.02(B). SECTION 6.02(B) of the Note Agreement is
hereby amended and restated to read in its entirety as follows:

              "(b) Liens existing on the date hereof listed on SCHEDULE 6.02
       hereto;"

       9. AMENDMENT TO SECTION 6.02(H). Section 6.02(h) of the Note Agreement is
hereby amended and restated to read in its entirety as follows:

              "(h) Liens securing Indebtedness permitted under Section
       6.01(a)(v) and (ix) and 6.01(b)(iv), so long as (i) in the case of
       Sections 6.01(a)(v) and 6.01(b)(iv), such Liens cover only the assets
       engineered, constructed, installed, acquired, developed or improved with
       such Indebtedness and (ii) in the case of Section 6.01(a)(ix), such Liens
       cover only Property constituting `Verizon Collateral' in accordance with
       the requirements of the Verizon Intercreditor Agreement;"

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                                      -4-

       10. AMENDMENT TO SECTION 6.05(A). Clauses (ii) and (iv) of Section
6.05(a) of the Note Agreement are hereby amended and restated to read in their
entirety as follows:

              "(ii) cash and Cash Equivalents, provided that all such cash and
       Cash Equivalents of the Obligors (other than up to $1,000,000 that may be
       held in operating deposit accounts and up to the amounts permitted by
       Section 6.05(a) of the Holdings Note Agreement to secure obligations in
       respect of letters of credit) is held in the Collateral Accounts under
       and as defined in the Senior Security Agreement;"

              "(iv) Investments by the Obligors in Metromedia Fiber Network
       (Bermuda) Ltd., a Bermuda company and a Wholly Owned Restricted
       Subsidiary, required under the consortium arrangements for the undersea
       cables of TAT-14, APCN-2 of which Metromedia Fiber Network (Bermuda) Ltd.
       is a member, in an aggregate amount (A) not to exceed $28,000,000 during
       the period commencing on the date hereof through and including December
       31, 2001 and (B) not to exceed $38,000,000 during the period commencing
       on the date hereof through and including December 31, 2002;"

       11. AMENDMENT TO SECTION 6.06(A). A new paragraph is hereby inserted at
the end of Section 6.06(a) of the Note Agreement to read as follows:

              "Notwithstanding the foregoing, Holdings will not, and will not
       permit any of its Subsidiaries to, sell any ownership interest in any
       allocated capacity in respect of the Japan-US Cable Network if the same
       would require that Holdings make an offer to purchase the notes issued
       under the Verizon Debt Agreement pursuant to Section 5.24 of the Verizon
       Indenture (as the Verizon Indenture is in effect on the Closing Date and
       without giving effect to any modifications or supplements thereto after
       the Closing Date)."

       12. AMENDMENT TO SECTION 6.08(1). CLAUSE (A) of SECTION 6.08(I) of the
Note Agreement is hereby amended and restated to read in its entirety as
follows:

              "(A) restrictions in effect on the date hereof and set forth on
       SCHEDULE 6.08 hereto;"

       13. AMENDMENT TO SECTION 6.12. SECTION 6.12 of the Note Agreement is
hereby amended and restated to read in its entirety as follows:

              "Section 6.12 MODIFICATIONS TO CERTAIN AGREEMENTS. None of the
       Obligors will, nor will it cause or permit any Restricted Subsidiary to,
       permit any waiver, supplement, modification, amendment, termination or
       release of (a) the Holdings Senior Notes or the Holdings Subordinated
       Notes (or any indenture relating thereto), (b) the Holdings Convertible
       Debt or Equity Documents, (c) the Verizon Debt Agreement or the Verizon
       Agreement, if, in the case of any modification to the Verizon Agreement,
       the same would result in (or would reasonably be expected to result in)
       the reduction of the aggregate amounts payable under the Verizon
       Agreement to Holdings and its Restricted Subsidiaries

<Page>
                                      -5-

       during calendar years 2001 and 2002 by more than 10% in either of such
       years, (d) any of the Holdings Notes Documents in any manner that would
       increase the amount of any Indebtedness thereunder, increase the rate of
       interest applicable to any Indebtedness thereunder, shorten the maturity
       date or the date for payment of any Indebtedness thereunder or otherwise
       be materially adverse to Holdings or any of its Subsidiaries or the
       Holders, or (e) any other Material Agreement, or its articles, charter or
       by-laws, in each case to the extent that any such waiver, supplement,
       modification, amendment, termination or release under this CLAUSE (E)
       could reasonably be expected (individually or in the aggregate) to have a
       Material Adverse Effect. Without limiting the generality of the
       foregoing, Holdings will not issue any shares of Disqualified Stock. "

       14. AMENDMENT TO SECTION 6.13(H). SECTION 6.13(H) of the Note Agreement
is hereby amended and restated to read in its entirety as follows:

              "(h) MAXIMUM CAPITAL EXPENDITURES. The Issuer will cause Holdings
       to not permit the aggregate amount of Capital Expenditures of Holdings
       and its Restricted Subsidiaries during any period set forth below to
       exceed the amount set forth opposite such period:

                                                                Maximum Capital
                          Period                                 Expenditures
                          ------                                 ------------

         Fiscal quarter ending September 30, 2001                $426,000,000
         Fiscal quarter ending December 31, 2001                 $126,000,000
         Fiscal year ending December 31, 2002                     $88,000,000
         Fiscal year ending December 31, 2003                     $98,000,000
         Fiscal year ending December 31, 2004                    $720,000,000
         Fiscal year ending December 31, 2005                    $104,000,000
         Fiscal year ending December 31, 2006                    $169,000,000

              If the aggregate amount of Capital Expenditures for any fiscal
       quarter or fiscal year (herein, a "FISCAL PERIOD") set forth above shall
       be less than the amount set forth opposite such Fiscal Period, then 50%
       of the shortfall shall be added to the amount of Capital Expenditures
       permitted for the immediately succeeding (but not any other) Fiscal
       Period and, for purposes hereof, the amount of Capital Expenditures made
       during any Fiscal Period shall be deemed to have been made first from the
       carryover from any previous Fiscal Period and last from the permitted
       amount for such Fiscal Period.

              The $426,000,000 figure set forth in the Schedule above for the
       fiscal quarter ending September 30, 2001 has been prepared under the
       assumption that not less than $201,000,000 of the equipment purchased
       from, or delivered by,

<Page>
                                      -6-

       Nortel Networks during such fiscal quarter would be treated as Capital
       Expenditures under GAAP. To the extent that, by reason of the execution
       and delivery of this Agreement such assumption is incorrect, then such
       $426,000,000 figure shall be reduced on a dollar-for-dollar basis by the
       amount of such equipment so purchased or delivered that is not treated as
       a Capital Expenditure under GAAP."

       15. AMENDMENTS TO SCHEDULE 4.01(K) AND SCHEDULE 4.01(V). Each of Schedule
4.01(k) and Schedule 4.01(v) of the Note Agreement is hereby amended and
restated to read in its entirety as set forth on SCHEDULE 4.01(K) and Schedule
4.01(v), respectively, attached hereto.

       16. AMENDMENT TO NOTE AGREEMENT. The Note Agreement is hereby amended by
adding SCHEDULES 4.01(J) 6.01, 6.02 and 6.08 thereto, each as set forth on
SCHEDULES 4.01(J), 6.01, 6.02 and 6.08, respectively, attached hereto.

       17. CONDITIONS PRECEDENT. The effectiveness of this Amendment is subject
to the satisfaction of each of the following conditions precedent, all of which
conditions precedent must be satisfied (unless otherwise agreed by the
Administrative Agent) on or before September 28, 2001: The Administrative Agent
shall have received all of the following, each dated (where applicable and
unless otherwise indicated) the date of this Amendment, in form and substance
satisfactory to the Administrative Agent:

              (a) AMENDMENT. This Amendment executed by the parties hereto; and

              (b) ADDITIONAL INFORMATION. Such additional agreements, documents,
       instruments and information (if any) as the Administrative Agent may
       reasonably request in connection with this Amendment.

       18. REPRESENTATIONS AND WARRANTIES. The Issuer hereby represents and
warrants to, and agrees with, the Administrative Agent and the Purchasers that,
as of the date of and after giving effect to this Amendment (a) the execution,
delivery and performance of this Amendment has been authorized by all requisite
corporate action on the part of the Issuer and will not violate the Issuer's
corporate charter or bylaws; (b) the term Note Documents as defined in the Note
Agreement and as used in any of the Note Documents includes, without limitation,
this Amendment; (c) all representations and warranties set forth in the Note
Documents are true and correct as if made again on and as of such date (except
if and to the extent that such representations and warranties were expressly
made only as of another specific date); (d) no Default or Event of Default has
occurred and is continuing; (e) there are no offsets, counterclaims or defenses
of any type to the Obligations under the Note Agreement; and (f) the Note
Agreement, the Security Documents and the other Note Documents (as amended by
this Amendment) are and remain legal, valid, binding and enforceable obligations
of the Issuer and the other Obligors (as applicable) which are parties thereto
in accordance with their terms.

       19. Governing Law. THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

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                                      -7-

       20. COUNTERPARTS. This Amendment may be executed in any manner of
counterparts, all of which when taken together shall constitute one agreement,
and any of the parties hereto may execute this Amendment by signing any such
counterpart.

       21. NO ORAL AGREEMENTS. THIS AMENDMENT, TOGETHER WITH THE NOTE AGREEMENT
AND THE OTHER NOTE DOCUMENTS AS WRITTEN, REPRESENT THE FINAL AGREEMENTS BETWEEN
AND AMONG THE PARTIES HERETO WITH RESPECT TO THE SUBJECT MATTER THEREOF AND MAY
NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT ORAL
AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN (A)
THE ISSUER OR ANY OTHER OBLIGOR AND (B) THE ADMINISTRATIVE AGENT OR ANY
PURCHASER.

       22. AGREEMENT REMAINS IN EFFECT, NO WAIVER. Except as expressly provided
herein, all terms and provisions of the Note Agreement and the other Note
Documents shall remain unchanged and in full force and effect and are hereby
ratified and confirmed. No waiver by the Administrative Agent or any Purchaser
of any Default or Event of Default shall be deemed to be a waiver of any other
Default or Event of Default. No delay or omission by the Administrative Agent or
any Purchaser in exercising any power, right or remedy shall impair such power,
right or remedy or be construed as a waiver thereof or an acquiescence therein,
and no single or partial exercise of any such power, right or remedy shall
preclude other or further exercise thereof or the exercise of any other power,
right or remedy under the Note Agreement, the Note Documents or otherwise.

       23. SURVIVAL OF REPRESENTATIONS AND WARRANTIES. All representations and
warranties made in this Amendment or any other Note Document shall survive the
execution and delivery of this Amendment and the other Note Documents, and no
investigation by the Administrative Agent or any Purchaser or any closing shall
affect the representations and warranties or the right of the Administrative
Agent and the Purchasers to rely upon such representations and warranties.

       24. REFERENCE TO NOTE AGREEMENT. This Amendment shall constitute a Note
Document. Each of the Note Documents, including the Note Agreement and any and
all other agreements, documents or instruments now or hereafter executed and/or
delivered pursuant to the terms hereof or pursuant to the terms of the Note
Agreement as amended hereby, are (if and to the extent necessary) hereby amended
so that any reference in such Note Documents to the Note Agreement shall mean a
reference to the Note Agreement as amended hereby.

       25. SEVERABILITY. Any provision of this Amendment held by a court of
competent jurisdiction to be invalid or unenforceable shall not impair or
invalidate the remainder of this Amendment and the effect thereof shall be
confined to the provision so held to be invalid or unenforceable.

       26. SUCCESSORS AND ASSIGNS. This Amendment is binding upon and shall
inure to the benefit of the Issuer, the Purchasers, the Administrative Agent and
their respective successors and assigns; provide , however, that the Issuer may
not assign or transfer any of its rights or obligations hereunder without the
prior written consent of the Purchasers.

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                                      -8-

       27. HEADINGS. The headings, captions and arrangements used in this
Amendment are for convenience only and shall not affect the interpretation of
this Amendment.

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                                      -9-

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

                               ISSUER:

                               METROMEDIA FIBER NETWORK
                               SERVICES, INC.

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

                               NORTEL NETWORKS INC.,
                                 as the Administrative Agent and as Purchaser

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

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