METROMEDIA FIBER NETWORK INC
S-4/A, 1999-02-11
TELEPHONE COMMUNICATIONS (NO RADIOTELEPHONE)
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<PAGE>
   
   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 11, 1999
    
 
   
                                                      REGISTRATION NO. 333-71129
    
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
 
                             WASHINGTON, D.C. 20549
                           --------------------------
 
   
                                AMENDMENT NO. 1
                                       TO
                                    FORM S-4
    
 
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                           --------------------------
 
                         METROMEDIA FIBER NETWORK, INC.
 
             (Exact name of Registrant as specified in its charter)
 
<TABLE>
<S>                              <C>                            <C>
           DELAWARE                          4813                  11-3168327
 (State or other jurisdiction    (Primary Standard Industrial    (IRS Employer
              of                 Classification Code Number)     Identification
incorporation or organization)                                        No.)
</TABLE>
 
                           ONE NORTH LEXINGTON AVENUE
                             WHITE PLAINS, NY 10601
                                  914-421-6700
 
         (Address, including zip code, and telephone number, including
            area code, of Registrant's principal executive offices)
 
                              STEPHEN A. GAROFALO
                      CHAIRMAN AND CHIEF EXECUTIVE OFFICER
                         METROMEDIA FIBER NETWORK, INC.
                           ONE NORTH LEXINGTON AVENUE
                             WHITE PLAINS, NY 10601
                                  914-421-6700
 
      (Name, address, including zip code, and telephone number, including
                        area code, of agent for service)
 
                                   Copies to:
 
                             DOUGLAS A. CIFU, ESQ.
                              JAMES M. DUBIN, ESQ.
                    PAUL, WEISS, RIFKIND, WHARTON & GARRISON
                          1285 AVENUE OF THE AMERICAS
                         NEW YORK, NEW YORK 10019-6064
                                  212-373-3000
 
    APPROXIMATE DATE OF PROPOSED SALE OF THE SECURITIES TO THE PUBLIC: As soon
as practicable after this Registration Statement becomes effective.
 
    If the securities being registered on this Form are being offered in
connection with the formation of a holding company and there is compliance with
General Instruction G, check the following box.  / /
 
    If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering.  / /
 
   
    If this Form is a post-effective amendment filed pursuant to Rule 462(d)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering.  / /
    
 
    THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933, AS AMENDED, OR UNTIL THIS REGISTRATION STATEMENT
SHALL BECOME EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION,
ACTING PURSUANT TO SAID SECTION 8(A), MAY DETERMINE.
 
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>
THE INFORMATION IN THIS PRELIMINARY PROSPECTUS IS NOT COMPLETE AND MAY BE
CHANGED. WE MAY NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED
WITH THE SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS PRELIMINARY
PROSPECTUS IS NOT AN OFFER TO SELL THESE SECURITIES AND IT IS NOT SOLICITING AN
OFFER TO BUY THESE SECURITIES IN ANY STATE WHERE THE OFFER OR SALE IS NOT
PERMITTED.
<PAGE>
   
                 SUBJECT TO COMPLETION, DATED FEBRUARY 11, 1999
    
 
PRELIMINARY PROSPECTUS
 
                         METROMEDIA FIBER NETWORK, INC.
 
   
                     OFFER TO EXCHANGE $650,000,000 OF ITS
                       10% SERIES B SENIOR NOTES DUE 2008
                           WHICH HAVE BEEN REGISTERED
                            UNDER THE SECURITIES ACT
                      FOR $650,000,000 OF ITS OUTSTANDING
                       10% SERIES A SENIOR NOTES DUE 2008
    
 
   
    Terms of the exchange offer
    
 
- --  It expires at 5:00 p.m., New York City time, on           , 1999, unless
    extended.
 
- --  It is subject to certain customary conditions, which we may waive.
 
   
- --  All initial notes that are validly tendered and not withdrawn will be
    exchanged.
    
 
   
- --  Tenders of initial notes may be withdrawn at any time prior to the
    expiration of the exchange offer.
    
 
   
- --  We will not receive any proceeds from the exchange offer.
    
 
   
- --  The terms of the exchange notes we will issue in the exchange offer are
    substantially identical to those of the initial notes, except that certain
    transfer restrictions and registration rights relating to the initial notes
    will not apply to the exchange notes.
    
 
   
Before participating in this exchange offer please refer to the section in this
Prospectus entitled "Risk Factors" commencing on page 11.
    
 
   
    Neither the Securities and Exchange Commission nor any state commission has
approved the notes to be distributed in the exchange offer, nor have any of
these organizations determined that this Prospectus is truthful or complete. Any
representation to the contrary is a criminal offense.
    
 
                            ------------------------
 
                 The date of this Prospectus is         , 1999.
 
                            ------------------------
<PAGE>
                               TABLE OF CONTENTS
 
   
<TABLE>
<CAPTION>
                                                                                                                PAGE
                                                                                                                -----
<S>                                                                                                          <C>
 
SUMMARY....................................................................................................           3
 
RISK FACTORS...............................................................................................          11
 
USE OF PROCEEDS............................................................................................          24
 
CAPITALIZATION.............................................................................................          25
 
SELECTED CONSOLIDATED FINANCIAL DATA.......................................................................          26
 
MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS......................          28
 
BUSINESS...................................................................................................          34
 
MANAGEMENT.................................................................................................          54
 
CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS.............................................................          62
 
SECURITY OWNERSHIP.........................................................................................          66
 
THE EXCHANGE OFFER.........................................................................................          68
 
DESCRIPTION OF THE EXCHANGE NOTES..........................................................................          79
 
CERTAIN UNITED STATES FEDERAL TAX CONSIDERATIONS...........................................................         115
 
PLAN OF DISTRIBUTION.......................................................................................         119
 
LEGAL MATTERS..............................................................................................         119
 
EXPERTS....................................................................................................         120
 
AVAILABLE INFORMATION......................................................................................         120
 
DOCUMENTS INCORPORATED BY REFERENCE........................................................................         121
 
INDEX TO CONSOLIDATED FINANCIAL STATEMENTS.................................................................         F-1
 
GLOSSARY...................................................................................................         A-1
</TABLE>
    
 
                                       2
<PAGE>
                               PROSPECTUS SUMMARY
 
   
    THIS SUMMARY HIGHLIGHTS SOME INFORMATION FROM THIS PROSPECTUS. BECAUSE IT IS
A SUMMARY, IT DOES NOT CONTAIN ALL OF THE INFORMATION THAT YOU SHOULD CONSIDER
BEFORE PARTICIPATING IN THE EXCHANGE OFFER. YOU SHOULD READ THE ENTIRE
PROSPECTUS CAREFULLY, INCLUDING THE SECTION ENTITLED "RISK FACTORS" AND THE
FINANCIAL STATEMENTS AND THE RELATED NOTES TO THOSE STATEMENTS INCLUDED IN THIS
PROSPECTUS. ALL SHARE AND PER SHARE INFORMATION IN THIS PROSPECTUS GIVES
RETROACTIVE EFFECT TO THE TWO-FOR-ONE STOCK SPLITS THAT BECAME EFFECTIVE ON
AUGUST 28, 1998 AND DECEMBER 22, 1998, OF THE SHARES OF CLASS A AND CLASS B
COMMON STOCK OF METROMEDIA FIBER NETWORK, UNLESS OTHERWISE INDICATED IN THIS
PROSPECTUS. WE ENCOURAGE YOU TO REFER TO THE GLOSSARY BEGINNING ON PAGE A-1 OF
THIS PROSPECTUS FOR A DEFINITION OF CERTAIN TECHNICAL TERMS USED IN THIS
PROSPECTUS.
    
 
                               THE EXCHANGE OFFER
 
   
    On November 25, 1998, we completed the private offering of $650,000,000
aggregate principal amount of our 10% Series A Senior Notes Due 2008. In
connection with this private offering, we entered into a registration rights
agreement with the initial purchasers of the initial notes. Under this
agreement, we agreed to deliver this Prospectus to you and to complete an
exchange offer for the initial notes on or before June 23, 1999. We are offering
to exchange $650,000,000 aggregate principal amount of our 10% Series B Senior
Notes Due 2008, which have been registered under the Securities Act of 1933, for
a like aggregate principal amount of our initial notes. You are entitled to
exchange your initial notes for exchange notes with substantially identical
terms in the exchange offer. You should read the discussions under the headings
"The Exchange Offer" and "Description of the Exchange Notes" for additional
information regarding the exchange offer and the exchange notes.
    
 
                                  THE COMPANY
 
GENERAL
 
   
    We are a facilities-based provider of technologically advanced,
high-bandwidth, fiber optic communications infrastructure to communications
carriers and corporate/government customers in the United States. We focus our
operations on domestic intracity fiber optic networks in clusters of the 15
largest cities in the United States based on population. We currently operate a
high-bandwidth fiber optic communications network in New York and within the
next two quarters expect to operate similar networks in Philadelphia and
Washington, D.C. We have also begun engineering and constructing networks in
Chicago, San Francisco and Boston and within the next two years, we also plan to
complete an expansion into five additional markets including Los Angeles,
Seattle, Dallas, Houston and Atlanta. We expect that our domestic intracity
networks will ultimately encompass approximately 810,000 fiber miles covering
approximately 1,896 route miles.
    
 
    We have also built or obtained intercity fiber optic capacity to link
certain of our intracity networks. We expect to have operational a 241 route
mile network from New York to Washington, D.C. during the first quarter of 1999,
and when finally complete, as currently planned, we expect that this network
will cover approximately 180,000 fiber miles. We have also obtained rights for
fiber optic capacity with other facilities-providers and obtained fiber optic
capacity linking certain of the metropolitan areas (New York--Chicago, New
York--Boston, Chicago--Seattle--Portland) in which we plan to construct
intracity networks, except in Portland.
 
   
    We expect that our entire network when completed, as currently planned, will
ultimately consist of approximately 1.1 million fiber miles covering
approximately 8,930 route miles. Please refer to the section in this Prospectus
entitled "Risk Factors--We Cannot Assure You That We Will Successfully Implement
our Business Strategy and Proposed Expansion, Which Could Adversely Affect our
Results of Operations."
    
 
                                       3
<PAGE>
   
    In addition, we have entered into a joint venture with a U.K.
telecommunications company to connect our New York network to London and we have
announced that we intend to form a joint venture to construct a high-bandwidth
fiber optic network connecting 13 major cities in Germany and obtain certain
additional fiber optic capacity in Western Europe. Please refer to the sections
in this Prospectus entitled "Business" and "Risk Factors--We Cannot Assure You
That We Will Successfully Implement Our Business Strategy and Proposed
Expansion, Which Could Adversely Affect Our Results of Operations."
    
 
   
    We expect that our entire network when completed, as currently planned, will
ultimately consist of approximately 1.1 million fiber miles covering
approximately 8,930 route miles. Please refer to the section in this Prospectus
entitled "Risk Factors--We Cannot Assure You That We Will Successfully Implement
our Business Strategy and Proposed Expansion, Which Could Adversely Affect our
Results of Operations."
    
 
   
BUSINESS STRATEGY
    
 
   
    Our objective is to become the preferred facilities-based provider of
broadband communications infrastructure to communications carriers, corporations
and government agencies, in our target markets. Please refer to the section in
this Prospectus entitled "Business--Business Strategy." The key elements of our
strategy to achieve this objective are to:
    
 
   
    - Establish Metromedia Fiber Network as the preferred carriers' carrier of
      broadband communications infrastructure.
    
 
   
    - Position Metromedia Fiber Network as the preferred provider of broadband
      communications infrastructure to corporate and government customers.
    
 
   
    - Replicate successful business model in new markets.
    
 
   
    - Create a low cost position.
    
 
   
    - Leverage network assets and strategic relationships to expand the reach of
      our networks.
    
 
   
    - Install a technologically advanced network.
    
 
   
    - Build on management experience and Metromedia Company relationship.
    
 
   
    Metromedia Fiber Network was founded in 1993 and is a Delaware corporation.
Our principal executive offices are located at One North Lexington Avenue, White
Plains, New York 10601. Our telephone number is (914) 421-6700.
    
 
                                       4
<PAGE>
                         SUMMARY OF THE EXCHANGE OFFER
 
   
    We are offering to exchange $650,000,000 aggregate principal amount of our
exchange notes for a like aggregate principal amount of our initial notes. In
order to exchange your initial notes, you must properly tender them and we must
accept your tender. We will exchange all outstanding initial notes that are
validly tendered and not validly withdrawn.
    
 
EXPIRATION DATE
 
   
    The exchange offer will expire at 5:00 p.m., New York City time, on,
            1999, unless we decide to extend it.
    
 
CONDITIONS TO THE EXCHANGE OFFER
 
   
    The exchange offer is subject to certain customary conditions, including
that:
    
 
   
    - there is no change in the laws and regulations which would impair our
      ability to proceed with the exchange offer,
    
 
   
    - there is no change in the current interpretation of the staff of the
      Securities and Exchange Commission which permits resales of the exchange
      notes.
    
 
   
    - there is no stop order issued by the staff of the Securities and Exchange
      Commission which would suspend the effectiveness of the registration
      statement of which this Prospectus is a part,
    
 
   
    - there is no litigation which would impair our ability to proceed with the
      exchange offer,
    
 
   
    - we obtain all the governmental approvals we deem necessary for the
      exchange offer, and
    
 
   
    - there is no change or development involving a prospective change in our
      business or financial affairs which might materially impair our ability to
      proceed with the exchange offer.
    
 
    Please refer to the section in this Prospectus entitled "The Exchange
Offer--Terms of the Exchange Offer--Conditions."
 
PROCEDURES FOR TENDERING INITIAL NOTES
 
   
    To participate in the exchange offer, you must complete, sign and date the
letter of transmittal, or a facsimile of the letter of transmittal, and transmit
it together with all other documents required by the letter of transmittal
(including the initial notes to be exchanged) to IBJ Whitehall Bank & Trust
Company, as exchange agent, at the address indicated on the cover page of the
letter of transmittal. In the alternative, you can tender your initial notes by
following the procedures for book-entry transfer described in this Prospectus.
If your initial notes are registered in the name of a broker, dealer, commercial
bank, trust company or other nominee, we urge you to contact that person
promptly to tender your initial notes in the exchange offer. For more
information on tendering your initial notes, please refer to the sections in
this Prospectus entitled "The Exchange Offer--Terms of the Exchange
Offer--Procedures for Tendering" and "--Book Entry Transfer."
    
 
GUARANTEED DELIVERY PROCEDURES
 
   
    If you wish to tender your initial notes and you cannot get your required
documents to the exchange agent on time, you may tender your initial notes
according to the guaranteed delivery procedures described under the section of
this Prospectus entitled "The Exchange Offer--Terms of the Exchange
Offer--Guaranteed Delivery Procedure."
    
 
                                       5
<PAGE>
WITHDRAWAL RIGHTS
 
   
    You may withdraw the tender of your initial notes at any time before 5:00
p.m., New York City time, on the expiration date of the exchange offer. To
withdraw, you must send a written or facsimile transmission notice of withdrawal
to the exchange agent at its address set forth under the "The Exchange
Offer--Exchange Agent" before 5:00 p.m., New York City time, on the expiration
date of the exchange offer.
    
 
ACCEPTANCE OF INITIAL NOTES AND DELIVERY OF EXCHANGE NOTES
 
   
    Subject to certain conditions, we will accept any and all initial notes that
are properly tendered in the exchange offer before to 5:00 p.m., New York City
time, on the expiration date. We will return any initial note that we do not
accept for exchange to you without expense as promptly as practicable after the
expiration date. We will deliver the exchange notes as promptly as practicable
after the expiration date and acceptance of the initial notes for exchange.
Please refer to the section in this Prospectus entitled "The Exchange
Offer--Terms of the Exchange Offer."
    
 
FEDERAL INCOME TAX CONSIDERATIONS RELATING TO THE EXCHANGE OFFER
 
   
    Exchanging your initial notes for exchange notes will not be a taxable event
to you for United States federal income tax purposes. Please refer to the
section of this Prospectus entitled "Certain United States Federal Tax
Considerations."
    
 
EXCHANGE AGENT
 
   
    IBJ Whitehall Bank & Trust Company is serving as exchange agent in the
exchange offer.
    
 
FEES AND EXPENSES
 
   
    We will bear all expenses related to the exchange offer. Please refer to the
section in this Prospectus entitled "The Exchange Offer--Fees and Expenses."
    
 
USE OF PROCEEDS
 
   
    We will not receive any proceeds from the issuance of the exchange notes. We
are making this exchange offer solely to satisfy certain of our obligations
under our registration rights agreement. Please refer to the sections in this
Prospectus entitled "Use of Proceeds" and "Management's Discussion and Analysis
of Financial Condition and Results of Operations--Liquidity and Capital
Resources" for a discussion of our use of the proceeds from the issuance of the
initial notes.
    
 
   
CONSEQUENCES OF FAILURE TO EXCHANGE INITIAL NOTES
    
 
   
    If you do not exchange your initial notes in this exchange offer, you will
no longer be able to obligate us to register the initial notes under the
Securities Act except in the limited circumstances provided under our
registration rights agreement. In addition, you will not be able to resell,
offer to resell or otherwise transfer the initial notes unless they are
registered under the Securities Act, or unless you resell, offer to resell or
otherwise transfer them under an exemption from the registration requirements
of, or in a transaction not subject to, the Securities Act. Please refer to the
section in this Prospectus entitled "Risk Factors--Your Failure to Participate
in the Exchange Offer Will Have Adverse Consequences."
    
 
                                       6
<PAGE>
                     SUMMARY OF TERMS OF THE EXCHANGE NOTES
 
ISSUER
 
    Metromedia Fiber Network, Inc.
 
NOTES OFFERED
 
   
    $650,000,000 aggregate principal amount of our 10% Series B Senior Notes Due
2008. The form and terms of the exchange notes are the same as the form and
terms of the initial notes except that the exchange notes will be registered
under the Securities Act will not bear legends restricting their transfer and
will not be entitled to registration rights under our registration rights
agreement. The exchange notes will evidence the same debt as the initial notes
and both the initial notes and the exchange notes will be governed by the same
indenture. In this Prospectus, we use the term "notes" when describing
provisions that apply to both the initial notes and the exchange notes.
    
 
MATURITY DATE
 
    November 15, 2008.
 
INTEREST ON THE EXCHANGE NOTES
 
   
    The exchange notes will accrue interest at the rate of 10% per year from
either the most recent date on which interest has been paid on the initial notes
you exchanged, or if no interest has been paid from November 25, 1998. We will
pay interest on the exchange notes semi-annually in arrears on May 15 and
November 15 of each year, commencing on May 15, 1999.
    
 
SINKING FUND
 
    None.
 
OPTIONAL REDEMPTION
 
   
    Except as described below, we may not redeem the exchange notes before
November 15, 2003. After November 15, 2003, we may redeem the exchange notes, in
whole or in part, at any time, at the redemption prices described in the
Prospectus under the heading "Description of the Exchange Notes," together with
accrued and unpaid interest, if any, to the date of redemption. In addition, at
any time and from time to time before November 15, 2001, we may redeem up to 35%
of the aggregate principal amount of the notes issued at a redemption price
equal to 110% of the principal amount of the notes redeemed, plus accrued and
unpaid interest, if any, through the date of redemption, if:
    
 
   
    - we use the net cash proceeds of any public equity offerings resulting in
      gross proceeds of at least $100 million, and
    
 
   
    - at least 65% of the aggregate principal amount of the notes issued remains
      outstanding immediately after giving effect to such redemption.
    
 
    Please refer to the section in this Prospectus entitled "Description of the
Exchange Notes-- Optional Redemption."
 
CHANGE OF CONTROL
 
   
    Upon a change of control of Metromedia Fiber Network, you will have the
right to require us to repurchase all of your exchange notes at a repurchase
price equal to 101% of the aggregate principal amount of such exchange notes,
together with accrued and unpaid interest, if any, to the date of
    
 
                                       7
<PAGE>
repurchase. Please refer to the section in this Prospectus entitled "Description
of the Exchange Notes--Change of Control."
 
RANKING
 
   
    The exchange notes will:
    
 
    - be general unsecured obligations,
 
   
    - rank without preference with all our other existing and future unsecured
      senior indebtedness,
    
 
   
    - be effectively subordinated to all our existing and future secured
      indebtedness to the extent of the assets that secure such indebtedness and
    
 
   
    - be effectively subordinated to all of our subsidiaries' existing or future
      indebtedness, whether or not secured.
    
 
RESTRICTIVE COVENANTS
 
   
    The indenture under which the exchange notes will be issued limit our and
our subsidiaries' ability to:
    
 
   
    - incur additional indebtedness or preferred stock,
    
 
   
    - pay dividends on, and repurchase or redeem our capital stock and our
      subsidiaries' capital stock and repurchase or redeem our subordinated
      obligations,
    
 
   
    - invest and sell assets and subsidiary stock,
    
 
   
    - engage in transactions with affiliates, and
    
 
   
    - incur additional liens.
    
 
   
    In addition, the indenture limits our ability to engage in consolidations,
mergers and transfers of substantially all of our assets and also contains
certain restrictions on distributions from our subsidiaries. All of these
limitations and prohibitions are subject to a number of important qualifications
and exceptions. Please refer to the sections in this Prospectus entitled "Risk
Factors-- Risk Factors Relating to the Notes" and "Description of the Exchange
Notes--Certain Covenants."
    
 
ABSENCE OF A PUBLIC MARKET FOR THE NOTES
 
   
    The exchange notes are new securities and there is currently no established
market for them. We cannot assure you that a market for the exchange notes will
develop or be liquid. The initial notes are currently eligible for trading in
the Private Offerings, Resales and Trading through Automated Linkages ("PORTAL")
market. Following commencement of the exchange offer, you may continue to trade
the initial notes in the PORTAL market. The exchange notes will not be eligible
for trading in the PORTAL market.
    
 
FORM OF EXCHANGE NOTES
 
   
    The exchange notes will be represented by one or more permanent global
securities in bearer form deposited on behalf of The Depository Trust Company
with IBJ Whitehall Bank & Trust Company, as custodian. You will not receive
exchange notes in registered form unless one of the events described in the
section of this Prospectus entitled "Description of the Exchange Notes--Book
Entry; Delivery and Form" occurs. Instead, beneficial interests in the exchange
notes will be shown on, and transfers of these will be effected only through,
records maintained in book-entry form by DTC with respect to its participants.
    
 
                                  RISK FACTORS
 
   
    You should consider carefully the information provided in the section in
this Prospectus entitled "Risk Factors" beginning on page 11 and all the other
information provided to you in this Prospectus in deciding whether to tender
your initial notes in the exchange offer.
    
 
                                       8
<PAGE>
                      SUMMARY CONSOLIDATED FINANCIAL DATA
 
   
    The summary consolidated financial data presented below as of and for the
periods ended December 31, 1995, 1996 and 1997 have been derived from our
Consolidated Financial Statements and the related notes included in this
Prospectus beginning on page F-1. Our Consolidated Financial Statements for the
year ended December 31, 1995 have been audited by M. R. Weiser & Co. LLP,
Certified Public Accountants. Our Consolidated Financial Statements as of and
for the years ended December 31, 1996 and 1997 have been audited by Ernst &
Young LLP, independent auditors. The summary consolidated financial data for the
nine months ended September 30, 1997 and the summary consolidated financial data
as of and for the nine months ended September 30, 1998 have been derived from
our unaudited Consolidated Financial Statements and the related notes included
in this Prospectus, which we believe include all adjustments necessary for a
fair presentation of the financial condition and results of operations of
Metromedia Fiber Network for such periods. The results of operations for interim
periods are not necessarily indicative of the results for a full year's
operations. You should read the following information in conjunction with
"Capitalization," "Management's Discussion and Analysis of Financial Condition
and Results of Operations," "Business," the Consolidated Financial Statements of
Metromedia Fiber Network and the related notes and the other financial data
appearing in this Prospectus.
    
 
<TABLE>
<CAPTION>
                                                                   YEAR ENDED                     NINE MONTHS
                                                                  DECEMBER 31,                ENDED SEPTEMBER 30,
                                                      ------------------------------------  -----------------------
<S>                                                   <C>         <C>          <C>          <C>          <C>
                                                         1995        1996         1997         1997         1998
                                                      ----------  -----------  -----------  -----------  ----------
STATEMENT OF OPERATIONS DATA:
Revenue.............................................  $   56,000  $   236,000  $ 2,524,000  $ 1,745,000  $20,840,000
Expenses:
  Cost of sales.....................................      --          699,000    3,572,000    2,647,000   9,499,000
  Selling, general and administrative...............   3,886,000    2,070,000    6,303,000    3,722,000   9,811,000
  Depreciation and amortization.....................     162,000      613,000      757,000      567,000     738,000
  Settlement agreement..............................      --          --           --           --        3,400,000
  Consulting and employment incentives..............      --        3,652,000   19,219,000   19,124,000     248,000
                                                      ----------  -----------  -----------  -----------  ----------
Loss from operations................................  (3,992,000)  (6,798,000) (27,327,000) (24,315,000) (2,856,000)
Interest income (expense), net......................    (327,000)  (3,561,000)   1,067,000     (241,000)  5,012,000
(Loss) from joint venture...........................      --          --           --           --         (264,000)
Income taxes........................................      --          --           --           --          825,000
                                                      ----------  -----------  -----------  -----------  ----------
Net (loss) income...................................  $(4,319,000) $(10,359,000) $(26,260,000) $(24,556,000) $1,067,000
                                                      ----------  -----------  -----------  -----------  ----------
                                                      ----------  -----------  -----------  -----------  ----------
Net (loss) income applicable to common stockholders
  per share.........................................  $    (0.17) $     (0.29) $     (0.56) $     (0.64) $      .01
                                                      ----------  -----------  -----------  -----------  ----------
                                                      ----------  -----------  -----------  -----------  ----------
Weighted average number of shares outstanding.......  24,829,000   35,858,000   47,447,000   38,652,000  93,196,000
                                                      ----------  -----------  -----------  -----------  ----------
                                                      ----------  -----------  -----------  -----------  ----------
EBITDA(1)...........................................  $(3,830,000) $(6,185,000) $(26,570,000) $(23,748,000) $(2,382,000)
Adjusted EBITDA(1)..................................  $(3,830,000) $(2,533,000) $(7,351,000) $(4,624,000) $1,266,000
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                        AS OF SEPTEMBER 30, 1998
                                                                                       --------------------------
<S>                                                                                    <C>          <C>
                                                                                                         AS
                                                                                         ACTUAL      ADJUSTED(2)
                                                                                       -----------  -------------
BALANCE SHEET DATA:
Cash.................................................................................  $76,335,000   $614,835,000
Pledged Securities...................................................................      --         91,500,000
Property and equipment, net..........................................................  150,311,000   150,311,000
Total assets.........................................................................  255,427,000   905,427,000
Long-term debt.......................................................................   19,687,000   669,687,000
Total liabilities....................................................................  100,685,000   750,685,000
Stockholders' equity.................................................................  $154,742,000  $154,742,000
</TABLE>
 
- ------------------------------
 
(1) "EBITDA" consists of earnings (loss) before income taxes plus all net
    interest expense and all depreciation and amortization expense. "Adjusted
    EBITDA" consists of earnings (loss) before income taxes plus all net
    interest expense, depreciation and amortization and noncash employment and
    consulting incentives and settlements. You should not think of EBITDA and
    Adjusted EBITDA as alternative measures of operating results or cash flows
    from operating activities (as determined in accordance with generally
    accepted accounting principles). We have included EBITDA and Adjusted EBITDA
    because they are widely used financial measures of the potential capacity of
    a company to incur and service debt. Our reported EBITDA and Adjusted EBITDA
    may not be comparable to similarly titled measures used by other companies.
 
   
(2) Adjusted for the issuance of the initial notes and the application of the
    proceeds thereof.
    
 
                                       9
<PAGE>
                       RATIO OF EARNINGS TO FIXED CHARGES
 
    The following table contains our ratio of earnings to fixed charges for each
of the periods indicated:
   
<TABLE>
<CAPTION>
                                                            PERIOD FROM                                                  NINE
                                                           APRIL 8, 1993                                                MONTHS
                                                             (DATE OF                                                    ENDED
                                                           INCEPTION) TO                   YEAR ENDED                  SEPTEMBER
                                                           DECEMBER 31,                   DECEMBER 31,                    30,
                                                          ---------------  ------------------------------------------  ---------
                                                               1993          1994       1995       1996       1997       1997
                                                          ---------------  ---------  ---------  ---------  ---------  ---------
<S>                                                       <C>              <C>        <C>        <C>        <C>        <C>
Ratio of earnings to fixed charges (1)..................        --            --         --         --         --         --
 
<CAPTION>
 
                                                            1998
                                                          ---------
<S>                                                       <C>
Ratio of earnings to fixed charges (1)..................       9.45
</TABLE>
    
 
- ------------------------------
 
   
(1) Earnings were insufficient to cover fixed charges until the nine month
    period ended September 30, 1998, and we expect earnings to be insufficient
    to cover fixed charges for some time thereafter as a result of the issuance
    of the notes. The deficiency was $188,000, $874,000, $4,319,000,
    $10,359,000, $26,260,000 and $24,556,000, for the periods ended December 31,
    1993, 1994, 1995, 1996, and 1997 and for the nine months ended September 30,
    1997 respectively.
    
 
                                       10
<PAGE>
                                  RISK FACTORS
 
   
    YOU SHOULD CAREFULLY CONSIDER THE INFORMATION BELOW, AS WELL AS ALL OTHER
INFORMATION PROVIDED TO YOU IN THIS PROSPECTUS, BEFORE TENDERING THE INITIAL
NOTES IN THE EXCHANGE OFFER, INCLUDING INFORMATION IN THE SECTION OF THIS
PROSPECTUS ENTITLED "MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
AND RESULTS OF OPERATIONS--SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS."
    
 
   
WE HAVE A LIMITED HISTORY OF OPERATIONS AND EXPECT TO CONTINUE TO INCUR NET
  LOSSES AND NEGATIVE CASH FLOW FROM OPERATIONS
    
 
   
    Metromedia Fiber Network was formed in April 1993 and has a limited
operating history. We currently have a limited number of customers and are still
in the process of building many of our networks. Accordingly, you will have
limited historical financial information upon which to base your evaluation of
our performance and an investment in the notes. You must consider our prospects
in light of the risks, expenses and difficulties frequently encountered by
companies in their early stage of development.
    
 
   
    In connection with the construction of our networks, we have incurred
substantial net losses, and we had never generated positive cash flow from
operations before the nine-month period ended September 30, 1998, except for the
months of March 1998, and June 1998. We expect to continue incurring losses
while we concentrate on the development and construction of additional fiber
optic networks and until our networks have established a sufficient
revenue-generating customer base. We also expect to incur losses during the
initial startup phases of any services that we may provide. Accordingly, we
expect to continue experiencing net operating losses and negative cash flows for
the foreseeable future. We cannot assure you that we will succeed in
establishing an adequate revenue base or that these services will generate
profitability or positive cash flow.
    
 
   
    Continued losses and negative cash flow may prevent us from pursuing our
strategies for growth and could cause us to be unable to meet our debt service
obligations (including our obligations under the notes), capital expenditure
requirements or working capital needs. Please refer to the section in this
Prospectus entitled "Management's Discussion and Analysis of Financial Condition
and Results of Operations."
    
 
   
WE HAVE SUBSTANTIAL DEBT WHICH MAY HAMPER OUR GROWTH AND WE MAY NOT BE ABLE TO
  MEET OUR OBLIGATIONS
    
 
   
    We have substantial debt and debt service requirements since the issuance of
the initial notes.
    
 
    Our substantial debt has important consequences, including:
 
    - our ability to borrow additional amounts for working capital, capital
      expenditures or other purposes is limited,
 
    - a substantial portion of our cash flow from operations is required to make
      debt service payments, and
 
   
    - our leverage could limit our ability to capitalize on significant business
      opportunities and our flexibility to react to changes in general economic
      conditions, competitive pressures and adverse changes in government
      regulation.
    
 
   
    We cannot assure you that our cash flow and capital resources will be
sufficient to repay the notes and any indebtedness we may incur in the future,
or that we will be successful in obtaining alternative financing. In the event
that we are unable to repay our debts, we may be forced to reduce or delay the
completion or expansion of our networks, sell some of our assets, obtain
additional equity capital or refinance or restructure our debt. Please refer to
the section in this Prospectus entitled "--We Cannot Assure You That We Will
Successfully Implement our Business Strategy and Proposed Expansion, Which Could
Adversely Affect our Results of Operations." If we are unable to meet our debt
service obligations or comply with our covenants, we will default under our
existing debt agreements. To avoid
    
 
                                       11
<PAGE>
   
a default, we may need waivers from third parties, which might not be granted.
You should also read the information we have included in this Prospectus in the
sections entitled "Description of the Exchange Notes" and "Business--Business
Strategy."
    
 
   
RESTRICTIONS IMPOSED BY OUR DEBT AGREEMENT MAY SIGNIFICANTLY LIMIT OUR ABILITY
  TO ENGAGE IN CERTAIN TRANSACTIONS
    
 
   
    The indenture for the notes contains a number of significant covenants.
These covenants will limit our ability to, among other things:
    
 
    - borrow additional money,
 
    - make capital expenditures and other investments,
 
    - pay dividends,
 
    - merge, consolidate, or dispose of our assets, and
 
    - enter into transactions with our affiliates.
 
   
    If we fail to comply with these covenants we will default under the
indenture. A default, if not waived, could result in acceleration of our
indebtedness, in which case the debt would become immediately due and payable.
If this occurs, we may not be able to repay our debt or borrow sufficient funds
to refinance it. Even if new financing is available, it may not be on terms that
are acceptable to us. Complying with these covenants may cause us to take
actions that we otherwise would not take, or not take actions that we otherwise
would take. Please refer to the section in this Prospectus entitled
"Management's Discussion and Analysis of Financial Condition and Results of
Operations--Liquidity and Capital Resources."
    
 
   
WE CANNOT ASSURE YOU THAT WE WILL SUCCESSFULLY IMPLEMENT OUR BUSINESS STRATEGY
  AND PROPOSED EXPANSION, WHICH COULD ADVERSELY AFFECT OUR RESULTS OF OPERATIONS
    
 
   
    Our future largely depends on our ability to implement our business strategy
and proposed expansion in order to create the new business and revenue
opportunities described in this Prospectus.
    
 
   
    Successful implementation depends on numerous factors beyond our control,
including economic, competitive and other conditions and uncertainties, the
ability to obtain licenses, permits, franchises and rights-of-way on reasonable
terms and conditions and the ability to hire and retain qualified management
personnel. The failure to obtain necessary licenses, permits and authorizations
could prevent or delay the completion of construction of all or part of our
networks or increase completion costs. In addition, construction of future
networks entails significant risks, including management's ability to
effectively control and manage these projects, shortages of materials or skilled
labor, unforeseen engineering, environmental or geological problems, work
stoppages, weather interference, floods and unanticipated cost increases. We
cannot assure you that the budgeted costs of our current and future projects
will not be exceeded or that these projects will commence operations within the
contemplated schedules, if at all.
    
 
    We will need to strengthen our marketing efforts and increase our staff to
handle future marketing and sales requirements. If we fail to obtain
significant, widespread commercial and public acceptance of our networks and
access to sufficient buildings our visibility in the telecommunications market
could be jeopardized. We cannot assure you that we will be able to secure
customers for the commercial use of our proposed networks or access to such
buildings in each market.
 
   
    The practice of leasing dark fiber is not widespread and we cannot assure
you that the market will develop or that we will be able to enter into
contracts, comply with the terms of these contracts or maintain relationships
with communications carriers and corporate and government customers. We also
cannot assure you that these contracts or relationships will be on economically
favorable terms or that communications carriers and corporate and government
customers will not choose to compete against, rather than cooperate with us. If
we are unable to enter into contracts, comply with the terms of the
    
 
                                       12
<PAGE>
contracts or maintain relationships with these constituencies our operations
would be materially and adversely affected.
 
   
    We cannot predict whether providing services to governments will evolve into
a significant market because governments usually already control existing
rights-of-way and often build their own communications infrastructure.
    
 
    Certain of our current contracts to supply leased fiber capacity allow the
lessee to terminate the contracts and/or provide for liquidated damages if we do
not supply the stated fiber capacity by a specified time. Some of these
contracts can be terminated on this basis. Terminating any of these contracts
could adversely affect our operations.
 
    We may expand the range of services that we offer. These services may
include assisting customers with the integration of their leased dark fiber with
appropriate electronic and optronic equipment by facilitating the involvement of
third party suppliers, vendors and contractors. We cannot assure you that a
market will develop for our new services, that implementing these services will
be technically or economically feasible, that we can successfully develop or
market them or that we can operate and maintain our new services profitably.
 
   
WE MAY BE UNABLE TO RAISE THE ADDITIONAL FINANCING NECESSARY TO BUILD OUT OUR
  NETWORKS AND IMPLEMENT OUR STRATEGY
    
 
    We may need significant amounts of additional capital to complete the
build-out of our planned fiber optic communications networks and meet our
long-term business strategies, including expanding our networks to additional
cities. Our ability to arrange financing and the cost of financing depend upon
many factors, including:
 
    - general economic and capital markets conditions generally, and in
      particular the non-investment grade debt market,
 
    - conditions in the telecommunications market,
 
    - regulatory developments,
 
    - credit availability from banks or other lenders,
 
   
    - investor confidence in the telecommunications industry and Metromedia
      Fiber Network,
    
 
    - the success of our fiber optic communications networks, and
 
    - provisions of tax and securities laws that are conducive to raising
      capital.
 
   
    If we need additional funds, our inability to raise them will have an
adverse effect on our operations. If we decide to raise additional funds by
incurring debt, we may become subject to additional or more restrictive
financial covenants and ratios.
    
 
   
INTENSE COMPETITION IN THE TELECOMMUNICATIONS INDUSTRY MAY AFFECT THE MARKET FOR
  OUR PRODUCTS AND OUR RESULTS OF OPERATIONS
    
 
   
    The telecommunications industry is extremely competitive, particularly with
respect to price and service. We compete against incumbent local exchange
carriers, which currently dominate their local telecommunications markets, and
competing carriers in the local services market, many of which have greater
financial, research and development and other resources than we do. In addition
to these carriers, several other potential competitors, such as facilities-based
communications service providers, cable television companies, electric
utilities, microwave carriers, satellite carriers, wireless telephone system
operators and large end-users with private networks, are capable of offering
services similar to those offered by us. A significant increase in industry
capacity or reduction in overall demand would adversely affect our ability to
maintain or increase prices. This would adversely affect our results of
operations.
    
 
                                       13
<PAGE>
    Some of our principal competitors already own fiber optic cables as part of
their telecommunications networks. Accordingly, any of these carriers, some of
which already have franchise and other agreements with the City of New York and
other local and state governments and substantially greater resources and more
experience than us, could directly compete with us in the market for leasing
fiber capacity, if they are willing to offer this capacity to their customers.
Our franchise and other agreements with the City of New York and other local and
state governments are not exclusive. Potential competitors with greater
resources and more experience than us could enter into franchise and other
agreements with the City of New York and other local and state governments and
compete directly with us.
 
    In addition, some communications carriers and local cable companies have
extensive networks in place that could be upgraded to fiber optic cable, as well
as numerous personnel and substantial resources to begin construction to equip
their networks. If communications carriers and local cable companies decide to
equip their networks with fiber optic cable, they could become significant
competitors of ours.
 
    Other companies may choose to compete with us in our current or planned
markets, including Europe, by leasing fiber capacity (including dark fiber) to
our targeted customers. This additional competition could materially and
adversely affect our operations.
 
    We are also particularly dependent on customers such as NextLink New York,
L.L.C., WinStar Communications, Inc. and certain other customers and are
therefore more susceptible to the impact of poor economic conditions than our
competitors with a more balanced mix of business. Please refer to the section in
this Prospectus entitled "Business--Customers."
 
   
THE TELECOMMUNICATIONS INDUSTRY IS HEAVILY REGULATED, WHICH MAY HAMPER OUR
  GROWTH
    
 
   
    Existing and future governmental regulations will greatly influence how we
operate our business, our business strategy and ultimately, our viability.
However, we cannot predict the future regulatory framework of our business.
Please refer to the sections in this Prospectus entitled "Business-- Regulation"
and "Business--Regulation of International Operations."
    
 
    FEDERAL
 
    Federal telecommunications law directly shapes the telecommunications
market. Consequently, regulatory requirements and/or changes could adversely
affect our operations.
 
   
    Federal telecommunications law imposes special legal requirements on "common
carriers" who engage in "interstate or foreign communication by wire or radio,"
and on "telecommunications carriers." We believe that we are not a
"telecommunications carrier" or "common carrier" with respect to our leasing of
dark fiber facilities, and therefore that we are not subject to special legal
requirements applicable to such carriers. However, with respect to offering of
telecommunications services, we will likely operate as a common carrier and
therefore will be subject to the regulatory requirements applicable to common
carriers and to telecommunications carriers. These regulatory requirements may
have a material adverse impact on our business and results of operation.
    
 
   
    If providing dark fiber facilities were deemed to be a "telecommunications"
service, then revenues from facility leases to end-users would be subject to
certain assessments by the Federal Communications Commission for its Universal
Service Fund.
    
 
   
    Local exchange carriers and long distance carriers are subject to various
federal telecommunications laws. These laws and Federal Communications
Commission regulatory decisions may affect our business by virtue of the
interrelationships that exist among us and many of these regulated
telecommunications entities. For example, the Federal Communications Commission
has recently taken steps to reduce the access charges paid by long distance
carriers to incumbent local exchange carriers, and to give the incumbent local
exchange carriers greater flexibility in setting these charges. While we cannot
predict the precise effect the access charge changes will have on our
    
 
                                       14
<PAGE>
   
operations, reduced access charges will likely make it more attractive for long
distance carriers to use incumbent local exchange carriers facilities, which
could have a material adverse effect on long distance carriers' use of our fiber
optic telecommunications network.
    
 
   
    Under the interconnection provisions of the Telecommunications Act of 1996,
the Federal Communications Commission is responsible for determining what
elements of an incumbent local exchange carrier's network must be provided to
competitors on an unbundled basis. Under these provisions, the Federal
Communications Commission has decided not to declare dark fiber an unbundled
network element, but has allowed state regulators to do so. This decision is
currently subject to petitions for reconsideration before the Federal
Communications Commission. A federal district court in North Carolina has found
dark fiber to be a network element under the Telecommunications Act of 1996.
Decisions by either the Federal Communications Commission or additional states
to require unbundling of incumbent local exchange carriers' dark fiber or
geographic extension of the ruling of the federal district court in North
Carolina could decrease the demand for our dark fiber, and thereby have an
adverse effect on the results of our operations.
    
 
   
    STATE
    
 
   
    Our offering of transmission services (as distinct from dark fiber capacity)
likely will be subject to regulation in each state (and the District of
Columbia, which is treated as a state for the purpose of regulation of
telecommunications services) to the extent that these services are offered for
intrastate use, and such regulation may have an adverse effect on the results of
our operations.
    
 
   
    Regulation of the telecommunications industry is changing rapidly, and the
regulatory environment varies substantially from state to state. In particular,
state regulators have the authority to determine both the rates we will pay to
incumbent local exchange carriers for certain interconnection arrangements such
as physical collocation, and the prices that incumbent local exchange carriers
will be able to charge our potential customers for services and facilities that
compete with ours. We will also incur certain costs to comply with regulatory
requirements such as the filing of tariffs, submission of periodic financial and
operational reports to regulators, and payment of regulatory fees and
assessments. In some jurisdictions, our pricing flexibility for intrastate
services may be limited because of regulation, although our direct competitors
will be subject to similar restrictions. We cannot assure you that these, as
well as future regulatory, judicial, or legislative action will not have a
material adverse effect on us.
    
 
    LOCAL
 
   
    Local governments exercise legal authority that may impact our business. For
example, local governments, such as the City of New York, typically retain the
ability to license public rights-of-way, subject to the limitation that local
governments may not prohibit persons from providing telecommunications services.
Local authorities affect the timing and costs associated with our use of public
rights-of-way. These regulations may have an adverse effect on our business.
    
 
    REGULATION OF INTERNATIONAL SERVICE
 
    Various regulatory requirements and limitations also will influence our
business as we attempt to enter international markets.
 
   
    Our U.K. joint venture with Racal Telecommunications, Inc., named
International Optical Network, LLC ("ION"), is a U.S. international common
carrier subject to U.S. regulation under Title II of the Communications Act of
1934. Depending on our specific business plans, it is possible that Metromedia
Fiber Network may also become a U.S. international common carrier subject to
such regulation. Under the current rules of the Federal Communications
Commission, international carriers that do not exercise market power and that
are not affiliated with dominant foreign carriers (those exercising market power
in their local markets), are subject to relatively relaxed U.S. regulation as
    
 
                                       15
<PAGE>
   
non-dominant international carriers. ION is, and Metromedia Fiber Network would
also be, required, under Sections 214 and 203 of the Communications Act of 1934,
respectively, to obtain authorization and file an international service tariff
containing rates, terms and conditions before initiating service. International
carriers are also subject to certain annual fees and filing requirements such as
the requirement to file contracts with other carriers, including foreign carrier
agreements, and reports setting forth international circuit, traffic and revenue
data service. A failure to obtain an appropriate U.S. license for international
service, the revocation of a license or a finding that one of our affiliates or
we are a dominant carrier could have a material adverse effect on our future
operations.
    
 
   
    To the extent that ION and Metromedia Fiber Network operate as international
common carriers, ION and Metromedia Fiber Network will also be required to
comply with the rules of the Federal Communications Commission regarding the
International Settlements Policy, which defines the permissible boundaries for
U.S. carriers and their foreign correspondents to settle the cost of terminating
each other's traffic over their respective networks.
    
 
   
    The Federal Communications Commission continues to refine its international
service rules to promote competition, reflect and encourage liberalization in
foreign countries, and reduce accounting rates toward cost. Please refer to the
section in this Prospectus entitled "Business--Regulation of International
Operations."
    
 
   
    Regulation of the international telecommunications industry is changing
rapidly. We are unable to predict how the Federal Communications Commission will
resolve the various pending international policy issues and the effect of such
resolutions on us.
    
 
    ION's international services are and our future international services may
also be subject to regulation in the United Kingdom and other European
jurisdictions in which we may operate. National regulations of relevant European
countries, as well as policies and regulations on the European Union level,
impose separate licensing, service and other conditions on ION's and our
international service operations, and these requirements may have a material
adverse impact on us.
 
   
OUR FRANCHISES, LICENSES OR PERMITS COULD BE CANCELLED OR NOT RENEWED, WHICH
  WOULD IMPAIR OUR OPERATIONS
    
 
   
    Termination or non-renewal of our franchise with the City of New York or of
certain other rights-of-way or franchises that we use for our networks would
have a material adverse effect on our business, results of operations and
financial condition. Please refer to the section in this Prospectus entitled
"Business--Franchise, License and Related Agreements." We will also need to
obtain additional franchises, licenses and permits for our planned intracity
networks, intercity networks and international networks. We cannot assure that
we will be able to maintain on acceptable terms our existing franchises,
licenses or permits or to obtain and maintain the other franchises, licenses or
permits needed to implement our strategy.
    
 
   
WE MAY NOT BE ABLE TO OBTAIN AND MAINTAIN THE RIGHTS-OF-WAY AND OTHER PERMITS
  NECESSARY TO IMPLEMENT OUR BUSINESS STRATEGY
    
 
   
    We must obtain additional rights-of-way and other permits from railroads,
utilities, state highway authorities, local governments and transit authorities
to install underground conduit(s) for the expansion of our intracity networks,
intercity networks and international networks. We cannot assure you that we will
be successful in obtaining and maintaining these right-of-way agreements or
obtaining these agreements on acceptable terms. Some of these agreements may be
short-term or revocable at will, and we cannot assure you that we will continue
to have access to existing rights-of-way after they have expired or terminated.
If any of these agreements were terminated or could not be renewed and we were
forced to remove our fiber optic cable from under the streets or abandon our
networks, the termination would have a material adverse effect on our
operations.
    
 
                                       16
<PAGE>
   
    More specifically, our New York/New Jersey network relies upon, and our
planned expansions into Long Island and Westchester County will rely upon,
right-of-way agreements with Bell Atlantic Corporation and its subsidiary,
Empire City Subway Company (Ltd.). The current agreements may be terminated at
any time without cause with three months notice. In case of termination, we may
be required to remove our fiber optic cable from the conduits or poles of Bell
Atlantic. This termination would have a material adverse effect on our
operations.
    
 
   
RAPID TECHNOLOGICAL CHANGES COULD AFFECT THE CONTINUED USE OF FIBER OPTIC CABLE
  AND OUR RESULTS OF OPERATIONS
    
 
    The telecommunications industry is subject to rapid and significant changes
in technology that could materially affect the continued use of fiber optic
cable. We cannot predict the effect of technological changes on our business. We
also cannot assure you that technological changes in the communications industry
will not have a material adverse effect on our operations.
 
   
WE MAY EXPERIENCE CERTAIN RISKS AS A RESULT OF EXPANDING OUR NETWORKS INTO
  FOREIGN COUNTRIES
    
 
   
    Our strategy includes expanding our services to provide fiber optic cable in
Europe, particularly Germany and London, England. The following are certain
risks we may experience as a result of doing business in Germany, England and
other foreign countries in which we may expand our networks:
    
 
   
    - regulatory limitations or restrictions imposed by the Federal
      Communications Commission, regulatory authorities of the European Union or
      countries in which we may operate,
    
 
   
    - unexpected changes by the Federal Communications Commission, the European
      Union, or the regulatory authorities of Germany, England or other
      countries in which we may operate, in regulatory requirements, tariffs,
      customs, duties and other trade barriers,
    
 
   
    - difficulties in staffing and managing our operations in London, England
      and Germany,
    
 
    - longer payment cycles,
 
    - problems in collecting accounts receivable,
 
   
    - political instability or changes in the political landscape of Germany,
      England or other countries in which we may operate,
    
 
    - fluctuations in the European currency exchange,
 
   
    - delays from customs brokers or government agencies encountered as a result
      of transacting business between us in the United States and our business
      associates in Germany, England or other countries in which we may operate,
      and
    
 
   
    - potentially adverse consequences resulting from operating in multiple
      European countries such as Germany and England which have different laws
      and regulations, including tax laws and industry related regulations.
    
 
   
    In addition, the international rates customers are charged are likely to
decrease in the future for many reasons, including increased competition between
existing carriers, increased competition with new carriers in the European
market and additional strategic alliances or joint ventures among large
international carriers that facilitate targeted pricing and cost reductions. We
cannot assure you that we will be successful in overcoming these risks or any
other problems arising because of expansion into Europe. Please refer to the
sections in this Prospectus entitled "Business--Regulation" and "Business--
Regulation of International Operations."
    
 
   
ACQUISITIONS, INVESTMENTS AND STRATEGIC ALLIANCES INVOLVE SERIOUS RISKS THAT MAY
  ADVERSELY AFFECT OUR RESULTS OF OPERATIONS
    
 
    In the future, we may acquire or try to acquire customer bases and
businesses from, make investments in, or enter into strategic alliances with,
companies which have customer bases, switching
 
                                       17
<PAGE>
capabilities or existing networks in our current markets or in areas into which
we intend to expand our networks. We are currently evaluating several potential
strategic opportunities but, except as described in this Prospectus, do not have
any present definitive commitment or agreement with respect to any material
acquisition, investment, strategic alliance or related effort. Any future
acquisitions, investments, strategic alliances or related efforts will be
accompanied by risks such as:
 
    - the difficulty of identifying appropriate acquisition candidates,
 
    - the difficulty of assimilating the operations of the respective entities,
 
    - the potential disruption of our ongoing business,
 
    - the inability of management to capitalize on the opportunities presented
      by acquisitions,
 
    - investments, strategic alliances or related efforts,
 
    - the failure to successfully incorporate licensed or acquired technology
      and rights into our services,
 
    - the inability to maintain uniform standards,
 
    - controls, procedures and policies, and
 
    - the impairment of relationships with employees and customers as a result
      of changes in management.
 
   
    We cannot assure you that we would be successful in overcoming these risks
or any other problems encountered with such acquisitions, investments, strategic
alliances or related efforts. Please refer to the sections in this Prospectus
entitled "--We Cannot Assure You That We Will Successfully Implement our
Business Strategy and Proposed Expansion, Which Could Adversely Affect our
Results of Operations" and "Business--Business Strategy."
    
 
   
THE TELECOMMUNICATIONS INDUSTRY IS EXPERIENCING PRICING PRESSURES AND A SHORTAGE
  OF CAPACITY
    
 
    We believe that, in the last several years, increasing demand has resulted
in a shortage of capacity and slowed the decline in prices. However, we
anticipate that prices for our services specifically, and transmission services
in general, will continue to decline over the next several years due primarily
to the following:
 
    - price competition as various network providers continue to install
      networks that might compete with our networks,
 
    - recent technological advances that permit substantial increases in the
      transmission capacity of both new and existing fiber, and
 
   
    - strategic alliances or similar transactions, such as long distance
      capacity purchasing alliances among certain regional Bell operating
      companies, that increase the parties' purchasing power.
    
 
    Please refer to the section in this Prospectus entitled "Management's
Discussion and Analysis of Financial Condition and Results of Operations."
 
   
OUR BUSINESS DEPENDS ON A LIMITED NUMBER OF KEY PERSONNEL THE LOSS OF WHOM COULD
  ADVERSELY AFFECT OUR BUSINESS
    
 
   
    Our business is managed by a small number of key management and operating
personnel. We believe that the success of our business strategy and our ability
to operate profitably depend on the continued employment of our senior
management team led by Stephen A. Garofalo, Chief Executive Officer and Chairman
of the Board of Directors. Our business and financial results could be
materially affected if Mr. Garofalo or other members of our senior management
team became unable or unwilling to continue in their present positions. Certain
of our key executives, Mr. Garofalo, Howard M. Finkelstein, President and Chief
Operating Officer, Vincent A. Galluccio, Senior Vice President, Gerard
Benedetto, Vice President and Chief Financial Officer, and Nicholas M. Tanzi,
Vice President-- Sales, are presently party to an employment or non-competition
agreement.
    
 
                                       18
<PAGE>
   
METROMEDIA COMPANY EFFECTIVELY CONTROLS METROMEDIA FIBER AND HAS THE POWER TO
  CAUSE OR PREVENT A CHANGE OF CONTROL
    
 
   
    The holders of our Class A Common Stock, par value $.01 per share, are
entitled to one vote per share. The holders of our Class B Common Stock, par
value $.01 per share, are entitled to ten votes per share and vote as a separate
class to elect at least 75% of the members of the board of directors of
Metromedia Fiber Network. Each share of Class B Common Stock is convertible at
any time into one share of Class A Common Stock, and with limited exceptions,
converts automatically upon any transfer of the stock. Stephen A. Garofalo
currently controls approximately 26% of the outstanding shares of Class A Common
Stock. Metromedia Company and certain of its affiliates currently own 100% of
the Class B Common Stock, which represents approximately 66% of Metromedia Fiber
Network's total voting power. Accordingly, Metromedia Company is able to control
the board of directors and all stockholders' decisions and, in general, to
determine (without the consent of Metromedia Fiber Network's other stockholders)
the outcome of any corporate transaction or other matter submitted to the
stockholders for approval, including mergers, consolidations and the sale of all
or substantially all of Metromedia Fiber Network's assets. In addition,
Metromedia Company has the power to prevent or cause a change in control of
Metromedia Fiber Network. Please refer to the sections in this Prospectus
entitled "Security Ownership" and "Certain Relationships and Related
Transactions."
    
 
   
WE ARE INVOLVED IN CERTAIN LEGAL PROCEEDINGS WHICH COULD ADVERSELY OUR FINANCIAL
  CONDITION
    
 
   
    We are involved in legal proceedings commenced by Vento & Company of New
York, LLC alleging four causes of action in connection with the sale of 900,000
shares (not adjusted for subsequent stock splits) of Class A Common Stock to
certain defendants on January 13, 1997. Vento & Company is seeking, among other
things, the rescission of the sale, or alternatively, damages in an amount which
we cannot currently ascertain but believe to be in excess of $36.0 million,
together with interest. Vento & Company is also seeking punitive damages in the
amount of $50.0 million, reasonable legal fees and the cost of this action. We
have moved to dismiss this complaint.
    
 
   
    We are involved in legal proceedings commenced by Claudio E. Contardi, who
alleges a cause of action for, among other things, breach of a finder's fee
agreement and breach of an implied covenant of good faith and fair dealing
contained in this agreement. Mr. Contardi is seeking, among other things, a
number of shares of Metromedia Fiber Network which we cannot currently ascertain
but believe to be approximately 225,000 shares (calculated as of the date on
which the complaint was filed) or damages in an amount which we cannot currently
ascertain but believe to be approximately $4.9 million (calculated as of the
date on which the complaint was filed) and all costs and expenses incurred by
him in this action. We have filed an answer to this complaint and have raised
affirmative defenses.
    
 
   
    We intend to vigorously defend both these actions because we believe that we
acted appropriately in connection with the matters at issue in these two cases.
However, we cannot assure you that we will not determine that the advantages of
entering into a settlement outweigh the risk and expense of protracted
litigation or that ultimately we will be successful in defending against these
allegations. If we are unsuccessful in defending against these allegations, an
award of the magnitude being sought in the legal proceedings with Vento &
Company would have a material adverse effect on our financial condition and
results of operations. Please refer to the section in this Prospectus entitled
"Business-- Legal Proceedings."
    
 
   
OUR SERVICES ARE LIMITED IN NATURE
    
 
   
    We provide fiber optic communications infrastructure and are not currently
engaged in the transmission of voice, data or video services. We do not provide
switched voice and data services, unlike other telecommunications companies.
Accordingly, we receive no revenues from providing such
    
 
                                       19
<PAGE>
services. Instead, we derive substantially all of our revenue from the leasing
of fiber optic capacity to our customers, many of whom transmit voice, data
and/or video information or provide switched voice and data services. While we
may later decide to provide those services, the limited nature of our current
services could limit potential revenues and result in our having lower revenues
than competitors which provide a wider array of services. Please refer to the
sections in this Prospectus entitled "Business--Customers" and
"Business--Competition."
 
   
WE HAVE SUBSTANTIAL HOLDINGS OF SECURITIES AND THE APPLICATION OF THE INVESTMENT
  COMPANY ACT COULD ADVERSELY AFFECT OUR BUSINESS AND OPERATIONS
    
 
   
    Following the offering of the initial notes, we have substantial cash, cash
equivalents and short-term investments. We invested approximately $91.5 million
of the net proceeds of the offering of initial notes in a portfolio of U.S.
government securities which we pledged to secure the payment in full of the
interest on the notes through May 15, 2000. We have invested the balance of such
proceeds in short-term instruments with prudent cash management and not
primarily for the purpose of achieving investment returns. Investment in
securities primarily for the purpose of achieving investment returns could
result in Metromedia Fiber Network being treated as an "investment company"
under the Investment Company Act of 1940. A company is considered an "investment
company" under the Investment Company Act if it holds itself out as primarily in
the business of investing, reinvesting or trading in securities. A company can
also be considered an "investment company" if it fails certain numerical tests
as to the composition of its assets and the sources of its income, even if it is
primarily engaged in a business other than investing, reinvesting, owning,
holding or trading in securities. The Investment Company Act requires investment
companies to register with the Securities and Exchange Commission and imposes
various substantive restrictions on investment companies with respect to matters
such as their capital structure, management, operations and transactions with
affiliated persons.
    
 
    We believe that we will not be considered to be engaged in investing,
reinvesting, owning, holding or trading securities, and therefore, will not be
regarded as an investment company within the meaning of the Investment Company
Act. However, application of such Act to us would materially adversely affect
our business, financial condition and results of operations.
 
   
WE MAY BE AFFECTED BY CERTAIN FAILURES TO ADDRESS THE "YEAR 2000 PROBLEM"
    
 
    Many computer systems and software products will not function properly in
the year 2000 and beyond due to a once-common programming standard that
represents years using two digits. This problem is often referred to as the
"Year 2000" problem. We are currently working to evaluate and resolve the
potential impact of the Year 2000 on our processing of date-sensitive
information and network systems. We plan to contact all our significant
suppliers, contractors and major systems developers to determine our
vulnerability to their Year 2000 situations. We presently believe that the Year
2000 problem will only have a minimal cost impact. However, we cannot assure you
that other companies will convert their systems on a timely basis and that their
failure will not have an adverse effect on our systems. If our customers,
suppliers, contractors, and major systems developers are unable to address their
Year 2000 issues in a timely manner, a material adverse effect on our results of
operations and financial condition could result. Please refer to the section in
this Prospectus entitled "Management's Discussion and Analysis of Financial
Condition and Results of Operations--Year 2000 System Modifications."
 
   
PAYMENT OF PRINCIPAL AND INTEREST ON THE NOTES IS EFFECTIVELY SUBORDINATED TO
  THE CLAIMS OF OUR SUBSIDIARIES' CREDITORS
    
 
   
    We are a holding company with few direct operations and few assets of
significance other than the stock of our subsidiaries. As such, we will be
dependent on the cash flows of our subsidiaries to meet our obligations,
including the payment of principal and interest on the notes. Our subsidiaries
are
    
 
                                       20
<PAGE>
   
separate legal entities that will have no obligation to pay any amounts due
under the notes or to make any funds available therefor, whether by dividends,
loans or other payments. Our subsidiaries do not guarantee the payment of the
notes. The notes will therefore be effectively subordinated to the claims of the
creditors of our subsidiaries (including trade creditors and holders of
indebtedness of such subsidiaries). We expect that our current and future
subsidiaries will incur significant amounts of equipment financing and other
indebtedness in connection with the development of our networks. Please refer to
the sections in this Prospectus entitled "Management's Discussion and Analysis
of Financial Condition and Results of Operations--Liquidity and Capital
Resources," "Business" and "Description of the Exchange Notes."
    
 
   
PAYMENT OF PRINCIPAL AND INTEREST ON THE NOTES IS EFFECTIVELY SUBORDINATED TO
  OUR SECURED DEBT AND OUR SUBSIDIARIES' DEBT
    
 
   
    The notes are unsecured and therefore will be effectively subordinated to
all our existing and future secured indebtedness to the extent of the value of
the assets securing such indebtedness. In addition, the notes will also be
effectively subordinated to all of our subsidiaries' existing or future
indebtedness, whether or not secured. The indenture for the notes permits us and
our subsidiaries to incur an unlimited amount of secured indebtedness to finance
the acquisition of equipment, inventory, construction, installation, lease,
development or improvement of network assets. Please refer to the section of
this Prospectus entitled "Description of the Exchange Notes." Consequently, in
the event of a bankruptcy, liquidation, dissolution, reorganization or similar
proceeding of Metromedia Fiber Network, the assets of Metromedia Fiber Network
will be available to satisfy obligations of such secured debt before any payment
may be made on the notes. In addition, to the extent such assets cannot satisfy
in full the secured indebtedness, the holders of such indebtedness would have a
claim for any shortfall that would rank equally in right of payment (or
effectively senior if the indebtedness were issued by a subsidiary) with the
notes. Accordingly, there might only be a limited amount of assets available to
satisfy your claims as a holder of the notes upon an acceleration of the
maturity of the notes.
    
 
   
A COURT COULD DECLARE THE NOTES VOID, SUBORDINATED OR TAKE OTHER ACTIONS
  DETRIMENTAL TO YOU
    
 
   
    An unpaid creditor or representative of creditors, such as a trustee in
bankruptcy or Metromedia Fiber Network as a debtor-in-possession in a bankruptcy
proceeding, could file a lawsuit claiming that the issuance of the notes
constituted a "fraudulent conveyance." To make such a determination, a court
would have to find that:
    
 
   
    - we did not receive fair consideration or reasonably equivalent value for
      the notes, and that,
    
 
   
    - at the time the notes were issued, we were insolvent or rendered insolvent
      by the issuance of the notes; were engaged in a business or transaction
      for which our remaining assets constituted unreasonably small capital; or
      intended to incur, or believed that we would incur, debts beyond our
      ability to pay such debts as they matured.
    
 
    If the court were to make such a finding, it could:
 
   
    - void our obligations under the notes,
    
 
   
    - subordinate the notes to other indebtedness, or
    
 
   
    - take other actions detrimental to you as a holder of the notes.
    
 
    The measure of insolvency for these purposes will vary depending upon the
law of the jurisdiction being applied. Generally, however, a company will be
considered insolvent for these purposes if the sum of that company's debts is
greater than the fair value of all of that company's property, or if the present
fair saleable value of that company's assets is less than the amount that will
be required to pay
 
                                       21
<PAGE>
   
its probable liability on its existing debts as they mature. Moreover,
regardless of solvency, a court could void an incurrence of indebtedness,
including the notes, if it determined that the transaction was made with intent
to hinder, delay or defraud creditors, or a court could subordinate the
indebtedness, including the notes, to the claims of all existing and future
creditors on similar grounds. We cannot determine in advance what standard a
court would apply to determine whether we were "insolvent" in connection with
the issuance of the notes. The measure of insolvency for purposes of determining
whether a fraudulent conveyance has occurred will vary depending upon the laws
of the relevant jurisdiction and upon the valuation assumptions and methodology
applied by the court.
    
 
   
YOU MAY FIND IT DIFFICULT TO SELL YOUR NOTES
    
 
   
    The initial notes were not registered under the Securities Act or under the
securities laws of any state and may not be resold unless they are subsequently
registered or resold pursuant to an exemption from the registration requirements
of the Securities Act and applicable state securities laws. The exchange notes
will be registered under the Securities Act but will constitute a new issue of
securities with no established trading market, and there can be no assurance as
to:
    
 
   
    - the development of any market for the exchange notes,
    
 
    - the liquidity of any such market that may develop,
 
   
    - your ability to sell your exchange notes, or
    
 
   
    - the price at which you would be able to sell your exchange notes.
    
 
   
    The initial notes are designated for trading among qualified institutional
investors in the PORTAL market. We have has been advised by the initial
purchasers for the notes that they presently intend to make a market in the
exchange notes. However, they are not obligated to do so and may discontinue any
such market-making activity with respect to the exchange notes at any time
without notice. Following commencement of the exchange offer, you may continue
to trade the initial notes in the PORTAL market. The exchange notes will not be
eligible for trading in the PORTAL market. Accordingly, we cannot assure you
that an active trading market will exist for the exchange notes or that such
trading market will be liquid. If such a market were to exist, the exchange
notes could trade at prices that may be higher or lower than their principal
amount or purchase price, depending on many factors, including prevailing
interest rates, the market for similar debentures and the financial performance
of Metromedia Fiber Network. Historically, the market for non-investment grade
debt has been subject to disruptions that have caused substantial volatility in
the prices of securities similar to the exchange notes. We cannot assure you
that the market for the exchange notes, if any, will not be subject to similar
disruptions. Any such disruptions may adversely affect you as a holder of the
exchange notes.
    
 
THE ISSUANCE OF THE EXCHANGE NOTES MAY ADVERSELY AFFECT THE MARKET FOR THE
  INITIAL NOTES
 
   
    If initial notes are tendered for exchange and accepted in the exchange
offer, the trading market for the untendered and tendered but unaccepted initial
notes could be adversely affected. Please refer to the section in this
Prospectus entitled "--Your Failure to Participate in the Exchange Offer Will
Have Adverse Consequences."
    
 
   
YOUR FAILURE TO PARTICIPATE IN THE EXCHANGE OFFER WILL HAVE ADVERSE CONSEQUENCES
    
 
   
    The initial notes were not registered under the Securities Act or under the
securities laws of any state and you may not resell them, offer them for resale
or otherwise transfer them unless they are subsequently registered or resold
under an exemption from the registration requirements of the Securities Act and
applicable state securities laws. If you do not exchange your initial notes for
exchange notes pursuant to the exchange offer, you will not be able to resell,
offer to resell or
    
 
                                       22
<PAGE>
   
otherwise transfer the initial notes unless they are registered under the
Securities Act or unless you resell them, offer to resell or otherwise transfer
them under an exemption from the registration requirements of, or in a
transaction not subject to, the Securities Act. In addition, you will no longer
be able to obligate us to register the initial notes under the Securities Act
except in the limited circumstances provided under our registration rights
agreement. In addition, if you want to exchange your initial notes in the
exchange offer for the purpose of participating in a distribution of the
exchange notes, you may be deemed to have received restricted securities, and,
if so, will be required to comply with the registration and prospectus delivery
requirements of the Securities Act in connection with any resale transaction.
    
 
AFFILIATES AND BROKER-DEALERS WHO PARTICIPATE IN THE EXCHANGE OFFER MUST DELIVER
  A PROSPECTUS IN CONNECTION WITH RESALES OF THE EXCHANGE NOTES
 
   
    Based on certain no-action letters issued by the staff of the Securities and
Exchange Commission, we believe that you may offer for resale, resell or
otherwise transfer the exchange notes without compliance with the registration
and prospectus delivery requirements of the Securities Act if:
    
 
   
    - you are acquiring the exchange notes in the ordinary course of your
      business,
    
 
   
    - you are not participating, do not intend to participate, and have no
      arrangement or understanding with any person to participate, in the
      distribution of the exchange notes within the meaning of the Securities
      Act, and
    
 
   
    - you are not a person that directly, or indirectly through one or more
      intermediaries, controls or is controlled by, or is under common control
      with, Metromedia Fiber Network.
    
 
   
    If any of the above is not true and you transfer any exchange note without
delivering a prospectus meeting the requirements of the Securities Act or
without an exemption from registration of your exchange notes under this Act,
you may incur liability under the Securities Act. We do not and will not assume
or indemnify you against such liability.
    
 
   
    Each broker-dealer that receives exchange notes for its own account in
exchange for initial notes which were acquired by such broker-dealer as a result
of market making or other trading activities may be deemed to be an
"underwriter" within the meaning of the Securities Act and must acknowledge that
it will deliver a prospectus meeting the requirements of the Securities Act in
connection with any resale of such exchange notes. The letter of transmittal
states that by so acknowledging and by delivering a prospectus, a broker-dealer
will not be deemed to admit that it is an "underwriter" within the meaning of
the Securities Act. A broker-dealer may use this Prospectus for any offer to
resell, resale or other transfer of the exchange notes. We have agreed that, for
a period of 180 days after the consummation of the exchange offer, we will make
this Prospectus available to any broker-dealer for use in connection with any
such offer to resell, resale or other transfer. Please refer to the section of
this Prospectus entitled "Plan of Distribution." Subject to certain limitations,
we will take steps to ensure that the issuance of the exchange notes will comply
with state securities or "blue sky" laws.
    
 
   
YOUR FAILURE TO ADHERE TO EXCHANGE OFFER PROCEDURES WILL HAVE ADVERSE
  CONSEQUENCES
    
 
   
    We will issue you the exchange notes pursuant to the exchange offer only
after the timely receipt of your initial notes, a properly completed and duly
executed letter of transmittal and all other required documents. Therefore, if
you want to tender your initial notes, please allow sufficient time to ensure
timely delivery. We are under no duty to give notification of defects or
irregularities with respect to the tenders of initial notes for exchange. Please
refer to the section in this Prospectus entitled "--Your Failure to Participate
in the Exchange Offer Will Have Adverse Consequences."
    
 
                                       23
<PAGE>
                                USE OF PROCEEDS
 
   
    We will not receive any cash proceeds from the issuance of the exchange
notes in exchange for the outstanding initial notes. We are making this exchange
offer solely to satisfy certain of our obligations under our registration rights
agreement. In consideration for issuing the exchange notes, we will receive
initial notes in like aggregate principal amount.
    
 
   
    The net proceeds to Metromedia Fiber Network from the original issuance of
the initial notes, after deducting discounts, commissions and expenses, were
approximately $630 million. We invested approximately $91.5 million of these net
proceeds in a portfolio of U.S. government securities, which we then pledged as
security for the payment in full of interest on the notes through May 15, 2000.
We intend to use the balance of such net proceeds for the build-out of our
intra-city and inter-city networks in the United States and Europe and for other
capital expenditures, working capital and general corporate purposes, including
possible acquisitions of other companies or assets. We currently intend to
allocate substantial proceeds to each of these uses. However, the precise
allocation of funds among these uses will depend on future technological,
regulatory and other developments in or affecting our business, the competitive
climate in which we operate and the emergence of future opportunities.
    
 
   
    We have invested such proceeds in U.S. government securities or other
short-term, interest bearing, investment grade securities. We are not currently
and do not expect as a result to become subject to the registration requirements
of the Investment Company Act of 1940. Please refer to the section in this
Prospectus entitled "Management's Discussion and Analysis of Financial Condition
and Results of Operations--Liquidity and Capital Resources."
    
 
                                       24
<PAGE>
                                 CAPITALIZATION
 
   
    The following table shows our capitalization as of September 30, 1998 and as
adjusted to reflect the issuance of the initial notes and the application of the
net proceeds therefrom. You should read this table together with the
Consolidated Financial Statements and related notes included in this Prospectus
beginning on page F-1 and the information in the section entitled "Management's
Discussion and Analysis of Financial Condition and Results of
Operations--Liquidity and Capital Resources."
    
 
<TABLE>
<CAPTION>
                                                                                    AS OF
                                                                              SEPTEMBER 30, 1998
                                                                      ----------------------------------
                                                                         ACTUAL          AS ADJUSTED
                                                                      -------------  -------------------
                                                                                (IN THOUSANDS)
<S>                                                                   <C>            <C>
Cash and cash equivalents...........................................   $    76,335       $   614,835
                                                                      -------------         --------
                                                                      -------------         --------
Pledged Securities: (1).............................................   $   --            $    91,500
                                                                      -------------         --------
                                                                      -------------         --------
Debt:
  Capital lease obligations less current portion....................   $    19,687       $    19,687
  10% Series A Senior Notes due 2008................................       --                650,000
                                                                      -------------         --------
  Total debt........................................................        19,687           669,687
                                                                      -------------         --------
Stockholders' equity
  Class A Common Stock, $.01 par value, 180,000,000 shares
    authorized; 77,460,452 shares issued and outstanding............           774               774
  Class B Common Stock, $.01 par value; 20,000,000 shares
    authorized; 16,884,636 shares issued and outstanding............           169               169
Additional paid-in capital..........................................       195,955           195,955
Accumulated deficit.................................................       (42,156)          (42,156)
                                                                      -------------         --------
  Total stockholders' equity........................................       154,742           154,742
                                                                      -------------         --------
Total capitalization................................................   $   174,429       $   824,429
                                                                      -------------         --------
                                                                      -------------         --------
</TABLE>
 
- ------------------------
 
   
(1) Represents amounts deposited with the security agent pursuant to our
    security agreement to make payments of interest on the notes through May 15,
    2000.
    
 
                                       25
<PAGE>
                      SELECTED CONSOLIDATED FINANCIAL DATA
 
   
    The selected consolidated financial data presented below as of and for the
years ended December 31, 1995, 1996 and 1997 have been derived from our
Consolidated Financial Statements and the related notes included in this
Prospectus beginning on page F-1. Our Consolidated Financial Statements for the
year ended December 31, 1995 have been audited by M. R. Weiser & Co. LLP,
Certified Public Accountants. Our Consolidated Financial Statements as of and
for the years ended December 31, 1996 and 1997 have been audited by Ernst &
Young LLP, independent auditors. The selected financial data presented below for
the period ended December 31, 1993 have been derived from our unaudited
financial statements which we believe include all adjustments necessary for a
fair presentation of the financial condition and results of operations of
Metromedia Fiber Network for such period. The selected consolidated financial
data and balance sheet data as of and for the nine months ended September 30,
1998 and the selected consolidated financial data for the nine months ended
September 30, 1997 have been derived from our unaudited Consolidated Financial
Statements and the related notes included in this Prospectus, which we believe
include all adjustments necessary for a fair presentation of the financial
condition and results of operations of Metromedia Fiber Network for such
periods. The results of operations for interim periods are not necessarily
indicative of the results for a full year's operations. You should read the
following information in conjunction with "Capitalization," "Management's
Discussion and Analysis of Financial Condition and Results of Operations,"
"Business," the Consolidated Financial Statements of Metromedia Fiber Network
and the related notes and the other financial data appearing in this Prospectus.
    
 
                                       26
<PAGE>
<TABLE>
<CAPTION>
                                   PERIOD FROM
                                     APRIL 8,
                                       1993
                                     (DATE OF                                                               NINE MONTHS
                                    INCEPTION)                          YEAR ENDED                             ENDED
                                        TO                             DECEMBER 31,                        SEPTEMBER 30,
                                   DECEMBER 31,  --------------------------------------------------------  -------------
                                       1993          1994          1995          1996           1997           1997
                                   ------------  ------------  ------------  -------------  -------------  -------------
<S>                                <C>           <C>           <C>           <C>            <C>            <C>
STATEMENT OF OPERATIONS DATA:
Revenue..........................   $       --   $         --  $     56,000  $     236,000  $   2,524,000  $   1,745,000
Expenses:
  Cost of sales..................           --             --            --        699,000      3,572,000      2,647,000
Selling, general and
  administrative.................      188,000        874,000     3,886,000      2,070,000      6,303,000      3,722,000
  Depreciation and
    amortization.................           --             --       162,000        613,000        757,000        567,000
  Settlement agreement...........           --             --            --             --             --             --
Consulting and employment
  incentives.....................           --             --            --      3,652,000     19,219,000     19,124,000
                                   ------------  ------------  ------------  -------------  -------------  -------------
Loss from operations.............     (188,000)      (874,000)   (3,992,000)    (6,798,000)   (27,327,000)   (24,315,000)
Interest income (expense), net...           --             --      (327,000)    (3,561,000)     1,067,000       (241,000)
(Loss) from joint venture........           --             --            --             --             --
Income taxes.....................           --             --            --             --             --             --
                                   ------------  ------------  ------------  -------------  -------------  -------------
Net (loss) income................     (188,000)       874,000    (4,319,000)   (10,359,000)   (26,260,000)   (24,556,000)
                                   ------------  ------------  ------------  -------------  -------------  -------------
                                   ------------  ------------  ------------  -------------  -------------  -------------
Net (loss) income applicable to
  common stockholders per
  share..........................   $    (0.03)  $      (0.04) $      (0.17) $       (0.29) $       (0.56) $       (0.64)
                                   ------------  ------------  ------------  -------------  -------------  -------------
                                   ------------  ------------  ------------  -------------  -------------  -------------
Weighted average number of shares
  outstanding....................    6,084,000     23,336,000    24,829,000     35,858,000     47,447,000     38,652,000
                                   ------------  ------------  ------------  -------------  -------------  -------------
                                   ------------  ------------  ------------  -------------  -------------  -------------
Ratio of Earnings to fixed
  charges(1).....................           --             --            --             --             --             --
EBITDA(2)........................   $ (188,000)  $   (874,000) $ (3,830,000) $   6,185,000  $ (26,570,000) $ (23,748,000)
Adjusted EBITDA (2)..............   $ (188,000)  $   (874,000) $ (3,830,000) $  (2,533,000) $  (7,351,000) $  (4,624,000)
 
<CAPTION>
 
                                       1998
                                   ------------
<S>                                <C>
STATEMENT OF OPERATIONS DATA:
Revenue..........................  $ 20,840,000
Expenses:
  Cost of sales..................     9,499,000
Selling, general and
  administrative.................     9,811,000
  Depreciation and
    amortization.................       738,000
  Settlement agreement...........     3,400,000
Consulting and employment
  incentives.....................       248,000
                                   ------------
Loss from operations.............    (2,856,000)
Interest income (expense), net...     5,012,000
(Loss) from joint venture........      (264,000)
Income taxes.....................       825,000
                                   ------------
Net (loss) income................     1,067,000
                                   ------------
                                   ------------
Net (loss) income applicable to
  common stockholders per
  share..........................  $       0.01
                                   ------------
                                   ------------
Weighted average number of shares
  outstanding....................    93,196,000
                                   ------------
                                   ------------
Ratio of Earnings to fixed
  charges(1).....................          9.45
EBITDA(2)........................  $ (2,382,000)
Adjusted EBITDA (2)..............  $  1,266,000
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                                     AS OF SEPTEMBER 30, 1998
                                                                                                   ----------------------------
<S>                                                                                                <C>            <C>
                                                                                                                       AS
                                                                                                      ACTUAL       ADJUSTED(3)
                                                                                                   -------------  -------------
BALANCE SHEET DATA
Cash.............................................................................................  $  76,335,000  $ 614,835,000
Pledged Securities...............................................................................             --  $  91,500,000
Property and equipment, net......................................................................    150,311,000    150,311,000
Total assets.....................................................................................    255,427,000    905,427,000
Long-term debt...................................................................................     19,687,000    669,687,000
Total liabilities................................................................................    100,685,000    750,685,000
Stockholders' equity.............................................................................  $ 154,742,000  $ 154,742,000
</TABLE>
 
- ------------------------
 
   
(1) Earnings were insufficient to cover fixed charges until the nine month
    period ended September 30, 1998, and we expect earnings to be insufficient
    to cover fixed charges for some time thereafter as a result of the issuance
    of the notes. The deficiency was $188,000, $874,000, $4,319,000,
    $10,359,000, $26,260,000 and $24,556,000, for the periods ended December 31,
    1993, 1994, 1995, 1996, and 1997 and for the nine months ended September 30,
    1997 respectively.
    
 
(2) "EBITDA" consists of earnings (loss) before income taxes plus all net
    interest expense and all depreciation and amortization expense. "Adjusted
    EBITDA" consists of earnings (loss) before income taxes plus all net
    interest expense, depreciation and amortization and non cash employment and
    consulting incentives and settlements. You should not think of EBITDA and
    Adjusted EBITDA as alternative measures of operating results or cash flows
    from operating activities (as determined in accordance with generally
    accepted accounting principles). We have included EBITDA and Adjusted EBITDA
    because they are widely used financial measures of the potential capacity of
    a company to incur and service debt. Our reported EBITDA and Adjusted EBITDA
    may not be comparable to similarly titled measures used by other companies.
 
   
(3) Adjusted to reflect the issuance of the initial notes and the use of the
    proceeds therefrom.
    
 
                                       27
<PAGE>
          MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
                           AND RESULTS OF OPERATIONS
 
    YOU SHOULD READ THE FOLLOWING INFORMATION TOGETHER WITH OUR CONSOLIDATED
FINANCIAL STATEMENTS AND THE RELATED NOTES INCLUDED IN THIS PROSPECTUS BEGINNING
ON PAGE F-1. CERTAIN STATEMENTS IN THIS SECTION ARE "FORWARD-LOOKING
STATEMENTS." YOU SHOULD READ THE INFORMATION UNDER "SPECIAL NOTE REGARDING
FORWARD-LOOKING STATEMENTS" LATER IN THIS SECTION FOR SPECIAL INFORMATION ABOUT
OUR PRESENTATION OF FORWARD-LOOKING INFORMATION.
 
GENERAL
 
   
    We are a facilities-based provider of technologically advanced,
high-bandwidth, fiber optic communications infrastructure to communications
carriers and corporate/government customers in the United States. We focus our
operations on domestic intracity fiber optic networks in clusters of the 15
largest cities throughout the United States based on population. We currently
operate high-bandwidth fiber optic communications networks in New York and
within the next two quarters expect to be operating similar networks in
Philadelphia and Washington, D.C. We have also begun engineering and
constructing networks in Chicago, San Francisco and Boston and within the next
two years, we plan to complete an expansion into five additional markets
including Los Angeles, Seattle, Dallas, Houston and Atlanta. We expect that our
domestic intracity networks will ultimately encompass approximately 810,000
fiber miles covering approximately 1,896 route miles.
    
 
    We have also obtained intercity fiber optic capacity that links certain of
our intracity networks. We expect to complete a 180,000 fiber mile or 241 route
mile network from New York to Washington, D.C. during the first quarter of 1999.
We have also obtained rights for fiber optic capacity with other
facilities-providers and obtained fiber optic capacity linking certain of the
metropolitan areas (New York--Chicago, New York--Boston,
Chicago--Seattle--Portland) in which we plan to construct intracity networks,
except in Portland.
 
   
    In addition, we have entered into a joint venture with a U.K.
telecommunications company to connect our New York network to London and we have
announced that we intend to form a joint venture to construct a high-bandwidth
fiber optic network connecting 13 major cities in Germany and obtain certain
additional fiber optic capacity in Western Europe. Please refer to the sections
in this Prospectus entitled "Business" and "Risk Factors--We Cannot Assure You
That We Will Successfully Implement our Business Strategy and Proposed
Expansion, Which Could Adversely Affect our Results of Operations."
    
 
RESULTS OF OPERATIONS
 
NINE MONTHS ENDED SEPTEMBER 30, 1998 COMPARED TO NINE MONTHS ENDED SEPTEMBER 30,
  1997:
 
    REVENUES for the nine months ending September 30, 1998 were $20.8 million or
1,124% greater than revenues of $1.7 million for the nine months of 1997. The
increase in revenue for the nine months ended September 30, 1998 versus the nine
months ended September 30, 1997 reflected higher revenues associated with
commencement of service to an increased total number of customers, as well as
revenue recognized related to grants of indefeasible rights of use to portions
of our network.
 
    COST OF SALES were $9.5 million in the nine months ending September 30,
1998, a 265% increase over cost of sales of $2.6 million for the first nine
months of 1997. Cost of sales increased for the nine months ended September 30,
1998 as compared to the same period in 1997 due to costs associated with the
commencement of service to customers, higher fixed costs associated with the
operation of our network in service and the allocated costs of the network
related to revenue recognized for grants of indefeasible rights of use to
portions of our network. Costs of sales as percentages of revenue for the
 
                                       28
<PAGE>
first nine months of 1998 and 1997 were 46% and 153%, respectively, declining as
a result of the significant increase in the number of customers and revenues.
 
    SELLING, GENERAL AND ADMINISTRATIVE EXPENSES increased to $9.8 million
during the first nine months of 1998, from $3.7 million during the first nine
months of 1997, an increase of $6.1 million, or 165%. The increase in selling,
general and administrative expenses for the nine-month period ended September
30, 1998 as compared to the nine-month period ended September 30, 1997 resulted
primarily from increased overhead to accommodate our network expansion.
 
    CONSULTING AND EMPLOYMENT INCENTIVES EXPENSE for the nine months ended
September 30, 1998 were $0.2 million compared with $19.1 million for the nine
months ended September 30, 1997. Consulting and employment incentives expense
incurred in 1997 reflects the value of stock options issued to key employees,
officers and directors in order to attract or retain their services. For the
nine months ended September 30, 1998, the amount recorded reflects amortization
for the unvested component of options issued in 1997 to key employees.
 
    SETTLEMENT AGREEMENT.  We recorded $3.4 million for a settlement agreement
in the nine months ended September 30, 1998. The amount was recorded in the
first quarter of 1998 for the expense associated with the issuance of stock
options and payment of cash related to the settlement agreement.
 
    DEPRECIATION AND AMORTIZATION EXPENSE was $0.7 million during the nine
months ended September 30, 1998, as compared to $0.6 million during the nine
months ended September 30, 1997, an increase of $0.1 million, or 17%. The
increases in depreciation and amortization expense resulted from increased
investment in our completed fiber optic network and property and equipment.
 
   
    INTEREST INCOME was $5.0 million during the nine months ended September 30,
1998 as compared to $0.5 million during the comparable 1997 period, an increase
of $4.5 million, or 900%. Interest income during 1998 was derived from
investment of our excess cash received as proceeds from our initial public
offering in October 1997.
    
 
   
    INTEREST EXPENSE decreased in the nine months ended September 30, 1998 to
$16,000 as compared to $732,000 for the nine months ended September 30, 1997.
The decrease in interest expense reflects the repayment of all of our debt in
1997 with the proceeds from the investment made by Metromedia Company in the
second quarter.
    
 
    INCOME (LOSS) FROM JOINT VENTURE.  We recorded a $264,000 loss from our 50%
share of the ION joint venture's loss for the nine-month period, ending
September 30, 1998. The loss primarily represents startup costs and operating
activities for the joint venture.
 
    INCOME TAXES.  We recorded a provision for income taxes for the nine-month
periods ended September 30, 1998 in the amount of $825,000. This represents an
estimated effective tax rate, for federal and state taxes, of 43.6%.
 
    NET INCOME was $1.1 million for the nine months ended September 30, 1998, as
compared to a net loss of $24.6 million for the comparable period of 1997. For
the nine months ended September 30, 1998, basic net income per share was $0.01
as compared to a basic net loss per share of $.64 for the nine months ended
September 30, 1997. On a diluted basis, net income per share for the nine months
ended September 30, 1998 was $0.01.
 
   
    The improvements in results for the nine-month period were primarily
attributable to the growth of revenues and the improvements in gross margins, as
noted above, as well as the increase in net interest income as compared to net
interest expense related to the investment made by Metromedia Company and the
funds raised through our initial public offering.
    
 
                                       29
<PAGE>
YEAR ENDED DECEMBER 31, 1997 COMPARED TO YEAR ENDED DECEMBER 31, 1996:
 
    REVENUES for 1997 were $2,524,311, a 969% increase as compared to 1996
revenues of $236,082. The revenue increase was generated by one time revenues
associated with commencement of services to customers as well as increased
recurring lease revenues which reflects the growth in the number of our
customers.
 
    COST OF SALES for 1997 were $3,572,005, an increase of 411% as compared to
the $698,793 which was recorded as cost of sales in 1996. The increase in cost
of sales was associated with the increased revenues. Cost of sales as a
percentage of revenues improved to 142% in 1997 from 296% in 1996. The
improvement in cost of sales as a percentage of revenues reflects the increases
in revenue outdistancing the increases in cost, as the components of cost were
mostly of a fixed nature.
 
    SELLING, GENERAL AND ADMINISTRATIVE EXPENSES increased to $6,303,041 in 1997
from $2,070,345 in 1996, a 204% increase. This increase resulted primarily from
increased legal expenses as a result of our increased business activities and
the increased staffing to accommodate our anticipated growth.
 
    CONSULTING AND EMPLOYMENT INCENTIVES EXPENSE of $19,218,591 was recorded in
1997 as compared to $3,652,101 in 1996. The 1997 expense represents the value of
stock options issued to key employees, officers, directors and consultants in
order to attract or retain their services. The amount recorded in 1996 reflects
the expense associated with issuance of stock and warrants to consultants in
consideration for services rendered.
 
    DEPRECIATION AND AMORTIZATION EXPENSE was $757,133 in 1997 as compared to
$612,530 in 1996. The increase in depreciation and amortization expense resulted
from increased investment in our fiber optic network.
 
    INTEREST INCOME of $1,808,007 was recorded in 1997 as compared to no
interest income during 1996. The interest income in 1997 arose from the
investment of our excess cash during the year. In 1996, we had no excess cash to
invest and, accordingly, earned no interest income.
 
   
    INTEREST EXPENSE (INCLUDING FINANCING COSTS) decreased in 1997 to $740,786
from $3,561,010 in 1996. The decrease in interest expense reflects the repayment
of all of our debt during the year with the proceeds of the investment made by
Metromedia Company, as well as lower financing costs. Please refer to the
section in this Prospectus entitled "Certain Relationships and Related
Transactions."
    
 
    NET LOSS.  We recorded a net loss of $26,259,238 in 1997 as compared to a
net loss of $10,358,697 in 1996. The increase in the net loss was primarily
attributable to costs associated with organizing to meet our growth objectives.
In particular, such costs include the consulting and employment incentive,
described above, to attract and retain key employees, officers and directors, as
well as increased overhead to meet our growth objectives.
 
YEAR ENDED DECEMBER 31, 1996 COMPARED TO YEAR ENDED DECEMBER 31, 1995:
 
    During the year ended December 31, 1995, we were in our early development
stage and did not generate our first revenues until the last three months of
1995 when customers began using our facilities.
 
    TOTAL REVENUES increased to $236,082 for the year ended December 31, 1996
from $56,149 for the year ended December 31, 1995, representing an increase of
$179,933. The increase in revenue was due primarily to an increase in the number
of our customers.
 
    COST OF SALES was $698,793 for the year ended December 31, 1996. We did not
record any cost of sales for the year ended December 31, 1995. The increase was
primarily attributable to the inclusion of
 
                                       30
<PAGE>
franchise fees and easement costs in cost of sales for 1996. In prior years such
fees were classified as selling, general and administrative expense.
 
    SELLING, GENERAL AND ADMINISTRATIVE EXPENSES decreased to $2,070,345 for the
year ended December 31, 1996 from $3,886,568 for the year ended December 31,
1995, representing a decrease of $1,816,223.
 
    CONSULTING AND EMPLOYMENT INCENTIVES were $3,652,101 for the year ended
December 31, 1996 as compared to none in 1995, reflecting our issuance of equity
instruments for consulting services.
 
    DEPRECIATION AND AMORTIZATION increased to $612,530 for the year ended
December 31, 1996 from $161,576 for the year ended December 31, 1995,
representing an increase of $450,954. We recognize certain components of
depreciation and amortization upon commencement of service to customers, which
did not occur until late 1995. As a result, depreciation and amortization in
1996 was larger than it was in 1995 due to the inclusion of a full year of
depreciation and amortization for such customers.
 
   
    INTEREST EXPENSE (INCLUDING FINANCING COSTS) increased to $3,561,010 for the
year ended December 31, 1996 from $327,106 for the year ended December 31, 1995,
representing an increase of $3,233,904. This increase was a result of additional
debt incurred in 1996 to finance construction of our New York/New Jersey network
and to fund our operations.
    
 
    NET LOSS increased to $10,358,697 for the year ended December 31, 1996 from
$4,319,101 for the year ended December 31, 1995, representing an increase of
$6,039,596. The increase in net loss is attributable to the factors discussed
above.
 
LIQUIDITY AND CAPITAL RESOURCES
 
   
    On November 3, 1997, our initial public offering of 36,432,000 shares of
Class A Common Stock generated net proceeds of $133.9 million, after deducting
the underwriters' commission and expenses relating to such initial public
offering.
    
 
   
    During 1997, we utilized $2.2 million for operating activities primarily to
prepay a long term, nonexclusive right-of-way in order to build-out a portion of
our network and also to meet our growth objectives. A portion of the operating
activities was funded by advance payments received from customers. In addition,
we utilized $19.7 million in 1997 for investing activities, primarily to
build-out our network. In 1997, $155.9 million of cash flows were provided by
financing activities reflecting the net proceeds of our initial public offering,
as discussed above, and by the equity investment in Metromedia Fiber Network of
$32.5 million made by Metromedia Company and certain of its affiliates on April
30, 1997, a portion of which was utilized to repay all our outstanding debt and
purchase all of Metromedia Fiber Network's Series A preferred stock outstanding
at April 30, 1997.
    
 
   
    Cash used in operating activities during 1996 was $2.8 million as compared
to $1.3 million in 1995. Cash was utilized in both years to support the
operations through our startup phase. Cash flows used in investing activities
were $1.1 million in 1996 and $4.2 million in 1995. The investing activities
cash outflows in both years were primarily used for the building of our New
York/New Jersey network. Financing activities provided cash flows of $4.3
million in 1996 and $5.2 million in 1995 with the issuance of equity in 1996 and
the issuance of debt in both 1996 and 1995. The cash flows from financing
activities in both 1996 and 1995 were utilized to fund our operating and
investing activities.
    
 
    For the nine months ended September 30, 1998, our operating activities
generated $16.9 million of cash, compared with a use of $3.9 million during the
comparable nine-month period of 1997. The increase in cash provided by
operations was primarily due to the increase in advance payments received from
customers as well as the improvement in net income as a result of increases in
revenues and interest income in the nine months ended September 30, 1998 as
compared to the nine months ended September 30, 1997. For the nine months ended
September 30, 1998, we used $80.3 million of cash for
 
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<PAGE>
   
investing activities as compared to $1.7 million for the comparable period in
1997. This increase was due primarily to investments in the expansion of our
networks and related construction in progress as well as capital contributions
to our ION joint venture and a deposit on our German network build. For the nine
months ended September 30, 1998, we received $0.9 million of net cash from
financing activities, compared to $21.9 million for the same period in 1997. The
cash from financing activities in 1998 came from the issuance of common stock
from exercises of warrants and options, while the 1997 amount related to the
sale of securities of Metromedia Fiber Network net of the repayment of certain
of our indebtedness.
    
 
   
    We anticipate that we will continue to incur net operating losses as we
expand and complete our existing networks, construct additional networks and
market our services to an expanding customer base. We anticipate spending
approximately $300 million for the year ending December 31, 1999 and
approximately $200 million for the year ending December 31, 2000 on the
build-out of our fiber optic networks in 11 of the 15 largest cities in the
United States based on population and our planned international networks. We
believe that the net proceeds of the offering of the initial notes, certain
vendor financing, cash on hand as of September 30, 1998 and cash generated in
1999 and 2000 (including advance customer payments), will be sufficient to fund
the planned build-out of our fiber optic networks and our other working capital
needs through the year ended December 31, 2000. The indenture for the notes
permits us to incur additional indebtedness to finance the construction of our
networks. As a result, we may also consider from time to time private or public
sales of additional equity or debt securities, entering into senior credit
facilities and other financings, depending upon market conditions, in order to
finance the continued build-out of our network. We cannot assure you that we
will be able to successfully consummate any such financing at all, or on
acceptable terms. Accordingly, we expect to continue experiencing net operating
losses and negative cash flows for the foreseeable future.
    
 
YEAR 2000 SYSTEM MODIFICATIONS
 
    We are currently working to evaluate and resolve the potential impact of the
Year 2000 on our processing of date-sensitive information and network systems.
The Year 2000 problem is the result of computer programs being written using two
digits (rather than four) to define the Year 2000, which could result in
miscalculations or system failures resulting from recognition of a date using
"00" as the year 1900 rather than the year 2000.
 
    We have delegated responsibility to a group of executives, to coordinate the
identification, evaluation and implementation of changes to computer systems and
applications necessary to achieve our goal of a Year 2000 date conversion which
would minimize the effect on our customers and avoid disruption to business
operations. We are also focusing on hardware and software tools, programming and
outside forces that may affect our operations, including our vendors, banks and
utility companies. Our analysis of the Year 2000 threat is ongoing and will be
continuously updated throughout 1998 and 1999 as necessary.
 
   
    We have completed a questionnaire and project plan to our systems and
operating personnel to identify all business and computer applications so that
we can identify potential compliance problems. We plan to initiate
communications with all of our significant customers, suppliers, contractors and
major systems developers to determine their plans to remedy any Year 2000 issues
that arise in their business with us. We plan to compile a database of
information based upon these responses, which we expect to complete during the
first quarter of 1999. To the extent problems are identified, we will implement
corrective procedures where necessary, then test the applications for Year 2000
compliance. We expect to complete this project prior to January 1, 2000.
    
 
    Based on preliminary data, our estimate is that the Year 2000 effort will
have a nominal cost impact, although we can make no assurances as to the
ultimate cost of the Year 2000 effort or the total cost of information systems.
Such costs will be expensed as incurred, except to the extent such costs are
 
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<PAGE>
incurred for the purchase or lease of capital equipment. We expect to make some
of the necessary modifications through our ongoing investment in system
upgrades. We believe that our exposure to this issue, based on our internal
systems, is somewhat limited by the fact that substantially all of our existing
systems have been purchased or replaced since 1996.
 
    As of January 1, 1999, we had incurred nominal consulting costs in respect
of our Year 2000 conversion effort. We have not deferred any other information
systems projects due to the Year 2000 efforts. We expect that the source of
funds for Year 2000 costs will be cash on hand. Accordingly, we plan to devote
the necessary resources to resolve all significant Year 2000 issues.
 
    If our customers, suppliers, contractors or major systems developers are
unable to resolve Year 2000 processing issues in a timely manner, a material
adverse effect on our results of operations and financial condition could
result.
 
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS
 
    Any statements in this Prospectus about our expectations, beliefs, plans,
objectives, assumptions or future events or performance are not historical facts
and are forward-looking statements. These statements are often, but not always,
made through the use of words or phrases such as "will likely result," "expect,"
"will continue," "anticipate," "estimate," "intend," "plan," "projection,"
"would" and "outlook." Accordingly, these statements involve estimates,
assumptions and uncertainties which could cause actual results to differ
materially from those expressed in them. Any forward-looking statements are
qualified in their entirety by reference to the factors discussed throughout
this Prospectus. The following cautionary statements identify important factors
that could cause our actual results to differ materially from those projected in
the forward-looking statements made in this Prospectus. Among the key factors
that have a direct bearing on our results of operation are:
 
    - general economic and business conditions; the existence or absence of
      adverse publicity; changes in, or failure to comply with, government
      regulations; changes in marketing and technology; changes in political,
      social and economic conditions;
 
    - competition in the telecommunications industry; industry capacity; general
      risks of the telecommunications industries;
 
    - success of acquisitions and operating initiatives; changes in business
      strategy or development plans; management of growth;
 
    - availability, terms and deployment of capital;
 
    - construction schedules; costs and other effects of legal and
      administrative proceedings;
 
    - dependence on senior management; business abilities and judgment of
      personnel; availability of qualified personnel; labor and employee benefit
      costs,
 
    - development risks; risks relating to the availability of financing; and
 
    - other factors referenced in this Prospectus.
 
    These and other factors are discussed in "Risk Factors" and elsewhere in
this Prospectus.
 
    Because the risk factors referred to above could cause actual results or
outcomes to differ materially from those expressed in any forward-looking
statements made by us, you should not place undue reliance on any such
forward-looking statements. Further, any forward-looking statement speaks only
as of the date on which it is made and we undertake no obligation to update any
forward-looking statement or statements to reflect events or circumstances after
the date on which such statement is made or to reflect the occurrence of
unanticipated events. New factors emerge from time to time, and it is not
possible for us to predict which will arise. In addition, we cannot assess the
impact of each factor on our business or the extent to which any factor, or
combination of factors, may cause actual results to differ materially from those
contained in any forward-looking statements.
 
                                       33
<PAGE>
                                    BUSINESS
 
THE COMPANY
 
    We are a facilities-based provider of technologically advanced,
high-bandwidth, fiber optic communications infrastructure to carrier and
corporate/government customers in the United States and Europe.
 
   
    THE INTRACITY NETWORKS.  We have installed local intracity networks that as
of January 1, 1999, consisted of approximately 160,000 fiber miles (the number
of strands of fiber in a length of fiber optic cable multiplied by the length of
the cable in miles) covering approximately 400 route miles (the number of miles
spanned by fiber optic cable calculated without including physically overlapping
segments of cable) in four major metropolitan areas (New York, Philadelphia,
Washington, D.C. and Chicago) that constitute key telecommunications markets
among the 15 largest cities in the United States based on population. We
currently operate a high bandwidth fiber optic communications network in the New
York metropolitan area and within the next two quarters will be operating such
networks in the Philadelphia and Washington, D.C. metropolitan areas.
    
 
    We are currently planning to expand our existing local intracity networks in
these metropolitan areas, which will bring our total infrastructure in these
markets to approximately 357,000 fiber miles covering approximately 846 route
miles. We have also begun engineering and constructing networks in the San
Francisco and Boston metropolitan areas.
 
    Within the next two years, we plan to complete an expansion into five
additional markets: Los Angeles, Seattle, Dallas, Houston and Atlanta. We
anticipate that our total intracity network infrastructure will encompass
ultimately approximately 810,000 fiber miles covering approximately 1,896 route
miles in the aggregate. We are currently in the planning process for
construction of these networks.
 
    THE INTERCITY NETWORKS.  In addition to intracity networks in these 11 major
metropolitan areas, we are expanding the capacity of our intercity network
between the New York and Washington, D.C. metropolitan areas to a total of
approximately 180,000 fiber miles covering approximately 241 route miles. We
have also obtained, through exchanges of fiber capacity or "fiber swaps" with
other carriers and in certain instances, the payment of certain additional
consideration, the right to use fiber optic strands linking New York--Chicago,
Chicago--Seattle--Portland and New York--Boston. These intercity networks give
us the ability to offer our customers not only capacity within the 11 major
metropolitan areas where we will operate networks within the United States but
also between many of these same markets.
 
   
    TRANSATLANTIC CONNECTIVITY.  We have entered into a 50/50 joint venture,
called ION, with Racal Telecommunications, Inc., a United Kingdom manufacturer
of electronics and other equipment and a provider of telecommunications
services. Through this joint venture, we are able to offer our customers
seamless broadband connectivity between our New York and other U.S. networks and
London.
    
 
    THE EUROPEAN NETWORKS.  We also plan to offer our customers an expanded
presence in Europe through:
 
   
    - a proposed joint venture with Carrier 1 Holdings, Ltd. and Viatel, Inc.
      that will develop a 1,350 route miles fiber optic telecommunications
      network in Germany connecting to 13 of its largest cities, including
      Hamburg, Berlin, Munich, Frankfurt and Dusseldorf, and
    
 
   
    - a proposed fiber swap with Viatel under which we would receive the right
      to use approximately 3,880 fiber miles covering approximately 970 route
      miles of a broadband fiber optic network that will travel between Germany,
      France, The Netherlands and the United Kingdom.
    
 
    We cannot assure you that we will be able to build or use these networks
because we have not entered into final agreements with Carrier 1 and Viatel.
 
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<PAGE>
   
    GENERAL.  We focus on leasing or otherwise making available for use our
broadband communications infrastructure to two main customer groups:
communications carriers and corporate/ government customers located in selected
top 15 cities in the United States based on population (or "Tier I" markets).
Our target carrier customers include a broad range of communications companies
such as:
    
 
   
    - incumbent local exchange carriers,
    
 
   
    - local exchange carriers competing with incumbent local exchange carriers
      in the local services market,
    
 
   
    - long distance carriers,
    
 
   
    - paging, cellular and PCS companies,
    
 
    - cable companies, and
 
   
    - vendors providing direct access to the Internet.
    
 
   
    These carrier customers typically lease fiber optic capacity with which they
develop their own communications networks as a lowcost alternative to building
their own infrastructure or purchasing metered services from incumbent local
exchange carriers or facilities-based competing carriers in the local services
market. Our corporate and government customers typically lease fiber optic
infrastructure and other broadband services on a point-to-point basis for
high-bandwidth, secure voice and data networks. We believe that we are
well-positioned to penetrate the corporate and government markets since we plan
to continue to install most of our fiber in Tier I markets. Please refer to the
section in this Prospectus entitled "--Customers."
    
 
    The fiber communications infrastructure leased to our customers provides
high-bandwidth capacity for customers that seek to establish secure
communications networks for the transmission of large amounts of voice, data and
video. For example, a pair of our fiber optic strands can transmit up to 8.6
gigabits of data per second or the equivalent of approximately 129,000
simultaneous voice conversations.
 
    We tailor the amounts of capacity leased to the needs of our customers.
Certain customers that lease fiber optic capacity from us connect their own
transmission equipment to the leased fiber, and therefore obtain a fixed-cost,
secure telecommunications alternative to the metered communications services
offered by traditional providers. Other customers that require lesser amounts of
transmission capacity will have the option to lease a much smaller broadband
capacity on our network, as we are able to divide a single strand of fiber into
multiple smaller communications channels. We believe that we have installation,
operating, and maintenance cost advantages per fiber mile relative to our
competitors because we generally install our networks with 432 fibers and may
install as many as 864 fibers per route mile as compared to a generally lower
number of fibers in existing competitive networks.
 
   
    Our intracity networks support a self-healing SONET (synchronous optical
network, which is an electronics and network architecture for variable bandwith
products which enables transmission of voice, data and video (multimedia) at
very high speeds) architecture that minimizes the risk of downtime in the event
of a fiber cut and provides our customers with high security and reliability. We
install most of our fiber inside high density polyethylene conduit to protect
the cable and, where practicable, we install additional unused conduits to
accommodate future network expansion.
    
 
   
    We benefit from the support of our controlling stockholder Metromedia
Company. On April 30, 1997, Metromedia Company and certain of its affiliates
made a substantial equity investment in Metromedia Fiber Network. Metromedia
Company and its partners own all of the outstanding shares of Class B Common
Stock. The Class B Common Stock is entitled to 10 votes per share and to vote
separately to elect at least 75% of the members of the Board of Directors. As a
result, Metromedia Company and its partners own and control approximately 64% of
the outstanding voting power (on a
    
 
                                       35
<PAGE>
   
fully diluted basis) of Metromedia Fiber Network. On October 28, 1997, we
successfully completed our initial public offering generating proceeds to
Metromedia Fiber Network of $135.5 million (after deducting underwriting
discounts but not deducting offering expenses).
    
 
   
    Metromedia Fiber Network was founded in 1993 and is a Delaware corporation.
    
 
BUSINESS STRATEGY
 
    Our objective is to become the preferred facilities-based provider of
broadband communications infrastructure to communications carriers, corporations
and government agencies, in our target markets. The following are the key
elements of our strategy to achieve this objective:
 
   
    ESTABLISH METROMEDIA FIBER NETWORK AS THE PREFERRED CARRIERS' CARRIER OF
     BROADBAND COMMUNICATIONS INFRASTRUCTURE.
    
 
   
    We lease broadband communications infrastructure on a fixed-cost basis to
various communications carriers, enabling them to compete in markets which were
previously difficult to penetrate due to limited and/or costly access to
high-bandwidth communications infrastructure. Specifically, we plan to lease
fiber infrastructure capacity within our target markets thereby enabling our
carrier customers to bypass the incumbent local exchange carriers and
facilities-based competing carriers in the local services markets. We believe
that we are currently the only company whose principal business is providing
dark fiber on a fixed-cost basis in local Tier I markets. Additionally, we plan
to lease capacity on our high-bandwidth, long-haul intercity network to provide
seamless connectivity between our various intracity networks. Our fixed-cost,
long-term contracts allow our carrier customers to access our Tier I markets
without incurring the high capital expenditures, many of the franchise and
licensing fees and long lead times usually associated with building their own
networks. We also believe that communications carriers may be more likely to
lease capacity from us rather than from a competitor since we currently have no
plans to offer communications infrastructure services on a metered basis,
choosing instead to position ourselves as a noncompeting provider of
infrastructure alternatives for local exchange carriers and long distance
carrriers. Please refer to the section in this Prospectus entitled
"--Customers."
    
 
   
    POSITION METROMEDIA FIBER NETWORK AS THE PREFERRED PROVIDER OF BROADBAND
     COMMUNICATIONS INFRASTRUCTURE TO CORPORATE AND GOVERNMENT CUSTOMERS.
    
 
    Our fiber optic network is expected to serve Tier I markets in which there
are a large number of corporations and government agencies that we believe have
significant unmet demand for communications capacity. These customers typically
lease broadband communications infrastructure from us connecting two or more of
their locations, creating secure networks for voice, video or data
communications. Our primary target customers are those with significant
transmission needs or who require a high degree of security. However, customers
seeking lesser amounts of broadband transmission capacity will have the option
of leasing smaller amounts of capacity from us. By providing leased capacity on
a fixed-cost rather than a metered basis, we believe our network will be more
economical for our corporate and government customers, while also providing the
ability to expand their usage for low marginal costs and enhanced reliability
and security. Please refer to the section in this Prospectus entitled
"--Customers."
 
    REPLICATE SUCCESSFUL BUSINESS MODEL IN NEW MARKETS.
 
    We seek to leverage the success we have begun to demonstrate in our existing
markets by replicating a similar network architecture in a number of additional
markets. Specifically we intend to:
 
    - begin the engineering and construction of five additional intracity
      networks bringing the number of our intracity networks to a total of
      eleven, and
 
    - replicate our successful domestic strategy in selected European markets.
 
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<PAGE>
   
    We expect that our entire network when completed, as currently planned, will
ultimately consist of approximately 1.1 million fiber miles covering
approximately 8,930 route miles. Please refer to the section in this Prospectus
entitled "Risk Factors--We Cannot Assure You That We Will Successfully Implement
our Business Strategy and Proposed Expansion, Which Could Adversely Affect our
Results of Operations."
    
 
    CREATE A LOW COST POSITION.
 
    We believe that we have established a low cost position relative to other
communications carriers primarily for the following reasons:
 
    - we generally install trunks of 432 fibers and may install up to as many as
      864 fibers per route mile, which we believe is substantially more fiber
      than many other communications carriers install, thereby reducing the per
      fiber mile cost to construct and operate our networks,
 
    - we will have a newly-constructed network with advanced fiber optic
      technology which we believe offers operating and maintenance cost
      advantages,
 
    - we believe that certain of our rights-of-way and franchises are valuable
      assets that will be costly and difficult for others to procure in the
      future, and
 
    - where practicable, we install spare conduit which will allow for expanded
      fiber optic capacity at a cost significantly below the cost of new
      construction.
 
    Our low cost position should allow us to remain price competitive with other
providers of fiber optic infrastructure and to lease our fiber infrastructure at
a price which customers will find more attractive than the cost of constructing
their own networks.
 
   
    LEVERAGE NETWORK ASSETS AND STRATEGIC RELATIONSHIPS TO EXPAND THE REACH OF
     OUR NETWORKS.
    
 
   
    We have also obtained long haul fiber capacity between certain of our
intracity networks on a selective basis which we can provide to customers as a
value-added service. As a result, at little incremental cost, we have
successfully been able to expand the reach of our network. In addition, we plan
to continue to enter into strategic partnerships with other communications
providers. For example, we seek to establish additional relationships such as
the one we have established with Racal Telecommunications, Inc. This
relationship established a 50/50 joint venture to link our U.S. network to Racal
Telecommunications' U.K. network to offer each of our customers seamless
broadband connectivity between New York and London.
    
 
    INSTALL A TECHNOLOGICALLY ADVANCED NETWORK.
 
    We have installed a technologically advanced network that we believe
provides the high levels of reliability, security and flexibility that our
target customers typically demand. Our domestic intracity networks support a
self-healing SONET architecture that minimizes interruption to service in the
event of a fiber cut. We also continuously monitor and maintain high quality
control of our network on a 24-hour basis through our network operations center.
Our network is capable of using the highest commercially available capacity
transmission (OC192) and thereby can support advanced, capacity-intensive data
applications such as Frame Relay, ATM, multimedia and Internet-related
applications.
 
    BUILD ON MANAGEMENT EXPERIENCE AND METROMEDIA COMPANY RELATIONSHIP.
 
   
    Our management team and Board of Directors include individuals with
communications industry expertise and extensive experience in network design,
construction, operations and sales. Our Chief Executive Officer and founder,
Stephen A. Garofalo, has approximately 25 years of experience in the cable
installation business. Howard Finkelstein, our President and Chief Operating
Officer, served in various capacities in Metromedia Company over a period of 16
years, including 9 years as President of Metromedia Company's long distance
telephone company, until its merger in 1993 with what is now MCI/WorldCom, Inc.
We also benefit from the communications industry expertise and corporate
    
 
                                       37
<PAGE>
   
governance experience of John W. Kluge, Stuart Subotnick and David Rockefeller.
As the owner of all of Metromedia Fiber Network's shares of Class B Common
Stock, Metromedia Company and its general partners control the board of
directors and all stockholder decisions and, in general, determine the outcome
of any corporate transaction or other matters submitted to the stockholders for
approval. Please refer to the sections in this Prospectus entitled "Risk
Factors--Metromedia Company Effectively Controls Metromedia Fiber Network and
Has the Power to Cause or Prevent a Change of Control" and "Certain
Relationships and Related Transactions."
    
 
BUILD-OUT OF NETWORKS
 
   
    We have concentrated on developing and constructing our networks. As we
discuss in more detail below we have either obtained or are currently pursuing
the acquisition of necessary licenses, franchises and rights-of-way to construct
these networks. In constructing our fiber optic networks, we seek to create
strategic alliances with the engineering and construction management firms that
have been engaged to develop routes and easements and manage deployment plans.
Firms with whom we are allied in this regard have deployed local loop network
infrastructure for regional Bell operating companies as well as for competing
carriers in the local services markets. Though we anticipate outsourcing much of
the actual construction to various construction firms, we maintain strict
oversight of the design and implementation of our fiber optic communications
networks. We utilize only advanced commercially available fiber. We have ordered
a substantial portion of our fiber optic cable from Lucent Technologies, Inc.
However, we believe that we could obtain advanced fiber from other suppliers on
acceptable terms.
    
 
   
    We intend to finance the build-out of our networks with the net proceeds we
received from the issuance of the initial notes, cash on hand, and revenues
generated from the sale of capacity on our networks, including substantial up
front payments for certain long term leases and rights to use agreements.
    
 
   
    THE NEW YORK NETWORK.  When complete, our intracity network in the New
York/New Jersey metropolitan area as currently planned will be approximately
169,400 fiber miles covering approximately 440 route miles. As expanded, the
entire New York/New Jersey network will create a SONET capable fiber ring
focused in Manhattan and extending into each of the other four boroughs, as well
as east to Brookhaven, Long Island, north to Stamford, Connecticut, and west to
Northern and Central New Jersey.
    
 
   
    THE PHILADELPHIA NETWORK.  When complete, our network in the Philadelphia
metropolitan area as currently planned will be approximately 29,000 fiber miles
covering approximately 67 route miles. As completed, the entire Philadelphia
network will create a SONET capable fiber ring throughout downtown Philadelphia
as well as the surrounding areas of Bala-Cynwyd, Bryn Mawr, Radnor, Berwyn,
Paoli, Malvern and King of Prussia.
    
 
   
    THE WASHINGTON, D.C. NETWORK.  When complete, our network in the Washington,
D.C. metropolitan area as currently planned will be approximately 55,000 fiber
miles covering approximately 127 route miles. As completed, the entire
Washington network will create a SONET capable fiber ring throughout Washington,
D.C. and will extend to vital government and business centers in Arlington,
Fairfax, the Dulles airport area, Bethesda, Rockville, Silver Spring and other
locations in northern Virginia and suburban Maryland.
    
 
   
    THE CHICAGO NETWORK.  When complete, our network in the Chicago metropolitan
area as currently planned will be approximately 104,000 fiber miles covering
approximately 212 route miles. As completed, the entire Chicago network will
create a SONET capable fiber ring throughout Chicago and will extend to Oak
Brook, Downers Grove, Franklin Park, Arlington Heights, Des Plaines, Rosemont,
Schaumburg and O'Hare Airport.
    
 
                                       38
<PAGE>
   
    THE OTHER INTRACITY NETWORKS.  Subject to the receipt of the necessary
franchises, licenses and rights-of-way, we plan to construct additional fiber
optic communications networks in San Francisco, Boston, Los Angeles, Seattle,
Dallas, Houston and Atlanta. Although we cannot assure you that we will obtain
the necessary franchises, licenses and rights-of-way in these cities or that
these franchises, licenses and rights-of-way will provide all of the rights
needed to implement our strategy on acceptable terms, we plan to construct our
networks in these cities in a manner similar to our existing networks.
Construction is under way in the San Francisco and the Boston metropolitan
areas. When complete, our network in the San Francisco metropolitan area as
currently planned will be approximately 65,000 fiber miles covering
approximately 150 route miles. As completed, the San Francisco network will
create a SONET capable fiber ring through San Francisco, San Mateo and San Jose.
When complete, our network in the Boston metropolitan area as currently planned
will be approximately 32,000 fiber miles covering approximately 75 route miles.
As completed, the Boston network will create a SONET capable fiber ring through
Cambridge, Newton, Wellesley, Bedford and Redford. We are currently in the
planning process for the construction of the other intracity networks. In
January 1999, we entered into an agreement to acquire a provider of dark fiber
that is constructing an intracity network in Dallas. Consummation of this
transaction is pending and subject to customary conditions.
    
 
    THE INTERCITY NETWORKS.  We are in the process of completing the
construction of our intercity network between New York City and Washington, D.C.
When we complete its construction, this intercity network will cover
approximately 180,000 fiber miles over approximately 241 route miles. When
completed, this network will extend from New York to Washington, D.C. and will
pass through Philadelphia, Pennsylvania, Wilmington, Delaware, and Baltimore,
Maryland. We have obtained all of the necessary rights-of-way for this network.
 
    We have also obtained, through exchanges of fiber capacity or "fiber swaps"
with other carriers and the payment of certain other consideration, the right to
use fiber optic strands linking New York and Chicago, Chicago and Seattle,
Seattle and Portland and New York and Boston. As a result of these transactions,
we have obtained approximately 33,000 fiber miles covering approximately 4,474
route miles of broadband fiber optic capacity. We believe we have the ability to
lease broadband capacity between our intracity networks that will enhance our
ability to market our intracity networks to both our carrier and corporate
customers. These intercity network agreements will give us the ability to offer
our customers not only capacity within 11 major metropolitan areas within the
United States but also seamless connectivity from coast to coast.
 
   
    THE INTERNATIONAL NETWORKS.  We have entered into a forty year agreement
with a subsidiary of Racal Telecommunications, Inc., a United Kingdom
manufacturer of electronics and other equipment and a provider of
telecommunications services, to create ION, a joint venture in which we hold a
50% equity interest. ION has obtained transatlantic fiber optic cable rights on
Gemini and AC-1 which link our New York network to London, England. Through ION,
we are able to offer our customers seamless broadband transatlantic
communications services between New York and London. Under the ION joint venture
agreement, each party may contribute additional capital as agreed by the
parties. As of September 30, 1998, we had made capital contributions of
approximately $2.8 million to ION. In May 1998, ION was awarded a 25 year term
contract in excess of $25 million from a leading provider of undersea cable
capacity to provide inland capacity services from such provider's undersea cable
landing stations in the U.K. and the U.S.
    
 
   
    We have entered into a letter of intent with Carrier 1 and Viatel to develop
jointly the German network of approximately 64,800 fiber miles covering
approximately 1,350 route miles. The German network will include 13 of Germany's
largest cities such as Hamburg, Berlin, Munich, Frankfurt and Dusseldorf. We
have also entered into a letter of intent for an exchange of fiber optic
capacity with Viatel. Under this second letter of intent, we would receive the
right to use approximately 3,880 fiber miles covering approximately 970 route
miles on the European network that will travel between France, Germany, The
Netherlands and the United Kingdom. We anticipate that both the German network
and
    
 
                                       39
<PAGE>
   
the European network will be high-capacity broadband networks capable of
supporting high-quality voice, video, internet protocol and data traffic and
built using a self-healing SONET architecture. Initially, we would develop the
German network jointly with Viatel and Carrier 1. Viatel would own just over
half of the development entity. Following completion of the German network, our
joint venture with Carrier 1 and Viatel would dissolve and we would end up
owning our own conduit of fiber infrastructure in Germany. We cannot assure you
that we will be able to obtain either or both of these networks because we have
not entered into final agreements with Carrier 1 and Viatel. Assuming we are
able to finalize and execute binding agreements with Carrier 1 and Viatel, we
believe that the German network will be completed in stages with the first
segment available by the second or third quarter of 1999.
    
 
TECHNOLOGY
 
    Our networks consist of fiber optic communications networks which allow for
high speed, high quality transmission of voice, data and video. Fiber optic
systems use laser-generated light to transmit voice, data and video in digital
formats through ultrathin strands of glass. Fiber optic systems are generally
characterized by large circuit capacity, good sound quality, resistance to
external signal interference and direct interface to digital switching equipment
or digital microwave systems.
 
    We plan to install backbone fiber optic cables containing up to 864 fiber
optic strands, which have significantly greater bandwidth than traditional
analog copper cables. Using current electronic transmitting devices, a single
pair of glass fibers used by our network can transmit up to 8.6 gigabits of data
per second or the equivalent of approximately 129,000 simultaneous voice
conversations, which is substantially more than traditional analog copper cable
installed in many current communications networks. We believe that continuing
developments in compression technology and multiplexing equipment will increase
the capacity of each fiber optic strand, thereby providing more bandwidth
carrying capacity at relatively low incremental costs. Our network is capable of
using the highest commercially available capacity transmission (OC192) and
thereby can handle advanced, capacity-intensive data applications such as voice
over Internet Protocol, video teleconferencing, Frame Relay, ATM, multimedia and
Internet-related applications.
 
    In our intracity networks, we offer end-to-end fiber optic capacity, capable
of utilizing SONET capable ring architecture, which has the ability to route
customer traffic in either direction around its ring design thereby assuring
that fiber cuts do not interrupt service to customers on our networks. Our
networks are also capable of supporting DWDM (dense wave division multiplexing).
Currently, a state-of-the-art network operating system continuously monitors and
maintains quality control of networks on a 24-hour basis, alerts us of any
degradation or loss of fiber capacity and pinpoints the location of such
degradation. This network operating system also enables us to repair or replace
impaired fiber without any loss of service. In addition, the monitoring system
automatically reroutes traffic in the event of a catastrophic break in the
system, enabling us to ensure that our customers obtain continuous service.
 
FRANCHISE, LICENSE AND RELATED AGREEMENTS
 
   
    When we decide to build a fiber optic communications network, our corporate
development staff seeks to obtain the necessary rights-of-way and governmental
authorizations. In some jurisdictions, a construction permit is all that is
required. In other jurisdictions, a license agreement, permit or franchise is
also required. Such licenses, permits and franchises are generally for a term of
limited duration. Where possible, rights-of-way are leased under multi-year
agreements with renewal options and are generally nonexclusive. We lease
underground conduit and pole space and other rights-of-way from entities such as
incumbent local exchange carriers, utilities, railroads, long distance carriers,
state highway authorities, local governments and transit authorities. We strive
to obtain rights-of-way that afford us the opportunity to expand our
communications networks as business develops. We currently
    
 
                                       40
<PAGE>
have all rights-of-way and other authorizations necessary for our intracity
networks in the New York, Philadelphia, and Chicago metropolitan areas.
 
   
    NEW YORK.  We have entered into a 15-year nonexclusive franchise agreement
with New York City to install, operate, repair, maintain, remove and replace
cable, wire, fiber or other transmission medium that may be used in lieu of
cable, wire or fiber on, over and under the inalienable property of New York
City in order to provide telecommunications services which originate and/or
terminate in or transit New York City. This agreement expires in December 2008
and provides that we may submit a written petition to New York City to renew the
term of the franchise at least 12 months (but not more than 18 months) before
the expiration of the 15 year term. However, New York City has no obligation to
renew this agreement. The City of New York has granted only seven franchises to
date. However, we are not aware of any limit on the number of franchises that
the City of New York may grant and believe that the City of New York has begun
the process that will result in the awarding of additional licenses.
    
 
   
    This agreement requires us to provide New York City with certain
telecommunications infrastructure and, by November 1999, to complete
construction of our initial network as described in the agreement. We believe
that we are on schedule to complete such construction. On December 21, 1998,
this agreement was amended to extend the period of time to June 30, 2001 to
complete construction of the initial backbone to the borough of Staten Island.
    
 
    Both New York City and we have the right, at any one time after December 20,
2000, upon six months notice, to renegotiate in good faith certain terms of this
agreement, including the annual compensation payable to New York City, based on
changes in technological, regulatory or market conditions which may occur after
the effective date of the agreement. If we cannot reach an agreement upon any
such renegotiation, the agreement will be subject to early termination on a date
which would be one half of the number of days between the date of the notice to
renegotiate and January 1, 2009.
 
   
    Under the agreement, we are obligated to pay New York City an annual
franchise fee at a rate of 5% of gross revenues for each year of the franchise.
All revenues received directly or indirectly by us or any of our affiliates from
or in connection with telecommunications services which originate in, terminate
in, or transit New York City constitute "gross revenues" for purposes of the
agreement. Revenues that are generated from transmissions which transit New York
City, but also include transmission through other areas, are to be prorated. We
are obligated to pay a minimum franchise fee to the City of New York of $200,000
per year.
    
 
   
    The agreement requires that we obtain the consent of New York City for any
acquisition of 5% or more of the shares of the Company by any person other than
Mr. Stephen A. Garofalo, Metromedia Company, Mr. Howard M. Finkelstein, Mr.
Peter Sahagen or any other 5% stockholder on the date of the consummation of our
initial public offering.
    
 
   
    We entered into a nonexclusive conduit occupancy agreement with Bell
Atlantic Corporation in May 1993. This agreement authorizes us to install our
cable facilities in Bell Atlantic's conduit system in New York. We are required
to pay Bell Atlantic certain rates and charges pursuant to the terms of this
agreement. This conduit occupancy agreement is terminable without cause by
either party upon three months' written notice. Under certain circumstances, a
petition may be brought to the Public Services Commission requesting that it
decide a dispute arising over termination prior to the termination of this
conduit occupancy agreement.
    
 
    On June 16, 1998, we entered into a nonexclusive franchise agreement with
the City of White Plains, New York, that grants us the necessary rights for our
expanded New York/New Jersey network in the White Plains area. Under this
agreement, we are obligated to pay the City of White Plains an annual franchise
fee at the rate of 5% of gross revenues generated from the network within the
White Plains area for fifteen years, renewable once. We do not anticipate that
this fee will result in a material
 
                                       41
<PAGE>
cost to us. Upon termination of this agreement, ownership of the
telecommunications network in the White Plains area will revert to the City of
White Plains at fair market value.
 
   
    PHILADELPHIA.  In the Philadelphia area, we have obtained all necessary
rights-of-way and authorizations for the Philadelphia network in the
Philadelphia metropolitan area under an ordinance from the City of Philadelphia.
The ordinance allows us, subject to certain conditions to be set forth under a
license agreement being currently negotiated with the City of Philadelphia, to
construct, maintain and operate, replace and remove a telecommunications system
in, under and across the public rights-of-way and city streets and/or to place
such telecommunications system within the existing facilities owned by Bell
Atlantic, PECO Energy Company, Southeastern Pennsylvania Transportation
Authority, Consolidated Rail Corporation or any other entity holding a grant by
way of ordinances from the City of Philadelphia within the Philadelphia
metropolitan area.
    
 
   
    CHICAGO.  In Chicago, we have also obtained the required franchises,
licenses, permits and other agreements needed to complete our Chicago network.
In addition, we have entered into agreements with various entities, which
provide us with infrastructure of approximately 4,300 fiber miles along
approximately 40 route miles on key routes within our Chicago market, in
addition to the necessary easements and rights-of-way for the Chicago network.
    
 
   
    WASHINGTON D.C.  In Washington, D.C., we have obtained rights-of-way and
authorizations for the Washington network in the District of Columbia under a
Certificate of Public Convenience and are in the process of obtaining all
necessary permits for the network in the downtown area. We do not anticipate any
difficulty in obtaining such permits. We are currently negotiating the necessary
franchise agreements with certain municipalities that make up part of the
expanded Washington network.
    
 
    We are currently pursuing our efforts to obtain all rights-of-way and
authorizations for the build-out of our networks in Los Angeles, San Francisco,
Boston, Seattle, Dallas, Houston and Atlanta. We have recently signed a conduit
agreement within the Bay Area Rapid Transit right-of-way for a portion of the
network in the San Francisco area, and have obtained the necessary permits for
our intracity network in the downtown San Francisco area. In January 1999, we
entered into an agreement to acquire a provider of dark fiber that is
constructing an intracity network in Dallas. Consummation of this transaction is
pending and subject to customary conditions.
 
SALES AND MARKETING
 
    Our sales and marketing strategy includes:
 
    - positioning ourselves as the preferred carriers' carrier of broadband
      communications infrastructure,
 
    - focusing on high dollar volume corporate and government customers, and
 
    - emphasizing the cost advantages which will allow us to lease our fiber
      optic infrastructure at fixed prices which represent potentially
      significant savings for our large volume carrier and corporate customers
      relative to their present build or buy alternatives.
 
   
    We also believe that communications carriers and corporate and government
customers will be attracted to our dark fiber product and our unmetered pricing
structure. Dark fiber is installed fiber optic cable which is not otherwise
carrying a signal originated by the service provider (i.e., Metromedia Fiber
Network), but which will carry a signal generated by the customer. We intend
initially to centralize our sales and marketing efforts on carrier customers
through a national sales team and we are currently in the process of hiring
additional sales professionals to focus on these customers. As we have
constructed fiber optic networks in new cities, we have hired sales forces in
these areas to target regional corporate, government and to a lesser extent
carrier customers and we plan to continue this strategy.
    
 
                                       42
<PAGE>
CUSTOMERS
 
   
    CARRIERS.  We expect that communications carriers will account for a
majority of our business. We currently target the major carriers, such as
resellers, data services, regional Bell operating companies, long distance
carriers, competing local exchange carriers, vendors providing direct access to
the Internet, wireless providers, and major information service providers. We
believe that we can compete effectively with other providers due to our rapid
deployment, pricing, reliability, customer service and the capacity of our
networks. We traditionally lease dark fiber to communications carriers,
providing them with point-to-point and long distance carriers point of presence
to end user non-switched access, which connects their customers to our network.
This enables them to eliminate or reduce costly access charges.
    
 
    We have entered into contracts with approximately 19 communications
carriers, including providers of wireless, cellular, internet, interexchange and
competitive local exchange services, as of January 1, 1999. In addition, we are
currently in the process of negotiating agreements with certain other major
communications carriers and will continue to target such carriers in the future.
 
   
    NEXTLINK AGREEMENTS.  In June 1997 and February 1998, we entered into two
major agreements with NextLink New York, L.L.C., a competitive local exchange
carrier, or its affiliates which provide NextLink with certain exclusive
long-term rights to certain fiber strands and innerducts on specified intracity
routes.
    
 
    Pursuant to the agreements, we received $11.0 million in scheduled up-front
payments and will receive an additional $92.0 million in additional payments
from NextLink. Of the $92.0 million, $11.75 million was paid up-front and $80.25
million has been placed in escrow and will be released to us periodically as
delivery of the fibers and innerducts are completed during 1998 and 1999 in
accordance with the agreement.
 
   
    We have also entered into an agreement with NextLink Illinois, Inc. that
provides for the sharing of certain construction costs in connection with the
build-out of our Chicago network.
    
 
   
    WINSTAR AGREEMENTS.  We are a party to agreements with WinStar
Communications, Inc., a national competitive local exchange carrier, for long
term leases of high-capacity fiber optic infrastructure on our intracity
networks in the New York, Washington, D.C., Philadelphia, Chicago and San
Francisco areas and on our intercity network from New York to Washington, D.C.
Pursuant to the agreements, we will receive in excess of $40.0 million in
payments from WinStar.
    
 
   
    CORPORATE/GOVERNMENT CUSTOMERS.  We expect that our corporate and government
customers, including members of the international financial and commercial
community, will primarily be entities with multiple locations and high volume
communications requirements. We expect to provide these customers with dedicated
point-to-point communications that have the capacity to carry a wide range of
communications services (e.g., high speed intranet access). We offer our
high-bandwidth services to such customers at prices that are lower than those
currently offered by regulated competitive local exchange carriers and incumbent
local exchange carriers. However, our customers currently provide their own
transmission or switching equipment.
    
 
   
    We believe that we can effectively compete for corporate and government
customers based upon price, nonmetered usage, reliability and solutions tailored
to the customers' needs. In addition, our New York/New Jersey network utilizes,
and the other intracity networks will permit use of, SONET technology, which
offers reliability that we believe is generally superior to that provided by the
incumbent local exchange carriers. We currently have dark fiber infrastructure
leasing arrangements with a variety of financial services firms, including
investment and commercial banks, securities and accounting firms and a financial
exchange, although we have not yet completed installation of the dark fiber to
be leased pursuant to certain of the contracts.
    
 
                                       43
<PAGE>
COMPETITION
 
   
    Fiber optic systems are currently under construction both locally and
nationally. In New York City, for example, seven franchisees have been granted
the right to install and operate a telecommunications network within the city.
Development of fiber optic networks is also continuing on a national scale. The
construction of these networks enables their owners to lease access to their
networks to other communications carriers or large corporate or government
customers seeking high bandwidth capacity, without these customers having to
incur costly expenditures associated with building networks of their own.
Alternatively, some network owners may choose to use their infrastructure to
provide switched voice and data services, competing directly with incumbent
local exchange carriers and long distance carriers. Currently, we do not provide
such services or plan to provide such services.
    
 
   
    In New York City, Philadelphia, Washington, D.C., and the other cities where
we plan to deploy fiber optic communications networks, we face significant
competition from the incumbent local exchange carriers, which currently dominate
their local communications markets. We also face competition from competitive
local exchange carriers and other potential competitors in these markets and
will face competition in the cities in which we plan to build our networks. Many
of our competitors have financial, management and other resources substantially
greater than ours, as well as other competitive advantages over us, including
established reputations in the communications market.
    
 
   
    Various communications carriers already own fiber optic cables as part of
their communications networks. Accordingly, each of these carriers could, and
some do, compete directly with us in the market for leasing fiber capacity. In
addition, although competitive local exchange carriers generally provide a wider
array of services to their customers than we presently provide to our customers,
competitive local exchange carriers nevertheless represent an alternative means
by which our potential customers could obtain direct access to a long distance
carrier point of presence or other site of the customer's choosing. Thus,
competitive local exchange carriers could compete with us.
    
 
    Some communications carriers and local cable companies have extensive
networks in place that could be upgraded to fiber optic cable, as well as
numerous personnel and substantial resources to undertake the requisite
construction to so equip their networks. To the extent that communications
carriers and local cable companies decide to equip their networks with fiber
optic cable, they are potential direct competitors provided that these
competitors are willing to offer this capacity to all of their customers.
 
   
    We believe that as competition in the local exchange market develops, a
fundamental division between the needs of corporate, governmental and
institutional end users and residential end users will drive the creation of
differentiated communications services and service providers. We believe that
the competitive local exchange carriers, long distance carriers, vendors
providing direct access to the Internet, wireless carriers and corporate and
government customers on which we focus will have distinct requirements,
including maximum reliability, consistent high quality transmissions, capacity
for highspeed data transmissions, diverse routing and responsive customer
service. We believe that we will be able to satisfy the needs of such customers.
    
 
REGULATION
 
   
    As explained in the section of this Prospectus entitled "Business--The
Company," we plan to offer telecommunications infrastructure to customers in two
forms. First, customers may lease fiber optic capacity from us and attach their
own transmission equipment (we call this "dark fiber"). Second, customers will
have the option to lease smaller amounts of broadband capacity (less than a full
strand of fiber) of facilities where we operate our own transmission equipment
(we call this "transmission services"). These two offerings are subject to
varying degrees of regulation in each of the jurisdictions in which we operate.
In the United States, some aspects of our services are regulated by the Federal
Communications Commission and various State regulatory bodies. In other
countries where we operate we may also be subject to regulations by the agencies
having jurisdiction over the provision of telecommunications services.
    
 
                                       44
<PAGE>
    FEDERAL
 
   
    In the United States, federal telecommunications law directly shapes the
market in which we compete. Telecommunications facilities and services are
subject to varying degrees of regulation by the Federal Communications
Commission pursuant to the provisions of the Communications Act of 1934, as
amended by the Telecommunications Act of 1996 and the Federal Communications
Commission regulations issued under these laws.
    
 
    Federal telecommunications law imposes special legal requirements on "common
carriers" who engage in "interstate or foreign communication by wire or radio,"
and on telecommunications carriers." Telecommunications carriers and common
carriers are essentially the same, and are companies that provide communications
services "directly to the public" or to all potential users on an indiscriminate
basis subject to standardized rates, terms, and conditions.
 
   
    DARK FIBER.  We believe that we are not a "telecommunications carrier" or
"common carrier" with respect to our leasing of dark fiber, and therefore that
these leases are not subject to special legal requirements applicable to such
carriers. First, we do not believe that the leasing of dark fiber is a
"telecommunications service" that is subject to Federal Communications
Commission regulation. The Federal Communications Commission generally regulates
"communication by wire or radio" or the "transmission" of "information of the
users' choosing," neither of which describes the leasing of dark fiber. Second,
we do not intend to offer dark fiber facilities as a common carrier, I.E., to
all potential users on an indiscriminate basis. Instead, we intend to enter into
individualized negotiations on a selective basis with prospective lessees of our
dark fiber to determine whether and on what terms to serve each potential
lessee. Our dark fiber offerings should therefore not be subject to the common
carrier jurisdiction of the Federal Communications Commission or to the common
carrier provisions of the Communications Act of 1934.
    
 
   
    If our offering of dark fiber facilities were deemed to constitute
"telecommunications," then our revenues from such leases to end users (but not
to other telecommunication carriers), whether or not provided on a common
carrier basis, would become subject to assessment for the Federal Communications
Commission's Universal Service Fund, a fund that was established by the Federal
Communications Commission pursuant to the Telecommunications Act of 1996 to
assist in ensuring the universal availability of basic telecommunications
services at affordable prices. Such assessments could create a liability equal
to a percentage of these gross revenues. We anticipate that the rate of
assessment would be approximately 4% of gross interstate and 1% of gross
intrastate end-user revenues for the year 1999, and may be higher in subsequent
years. We may also be liable for assessments by state commissions for state
universal service programs.
    
 
   
    TRANSMISSION SERVICES.  With respect to our offering of telecommunications
transmission services, we will likely offer some of these services as a common
carrier (I.E., we will offer such transmission services to all potential users
indiscriminately) and therefore will be subject to the regulatory requirements
applicable to these carriers. For example, we will be required, with respect to
our transmission services, to (1) provide such services indiscriminately upon
any reasonable request; (2) charge rates and adopt practices, classifications
and regulations that are just and reasonable; and (3) avoid unreasonable
discrimination in charges, practices, regulations, facilities and services. We
may also be required to file tariffs setting forth the rates for our services.
Under current Federal Communications Commission policies, these regulatory
requirements should not impose any substantial burdens on us. The Federal
Communications Commission has recently determined, for example, that providers
of "access" services (intracity transmission services used to originate and/or
terminate interstate and foreign communications) need not file tariffs and may
offer such services to customers on a private, contractual basis. Our revenues
from transmission services will also be subject to Federal Communications
Commission Universal Service Fund assessments as discussed above, to the extent
that these services are purchased by end users and to other Federal
Communications Commission fees and assessments. Since the revenues of our
competitors will be subject to comparable assessments, this should not reduce
our competitiveness.
    
 
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<PAGE>
   
    Also, having some of our services regulated as a "telecommunications
carrier" will give us certain legal benefits. In particular, we will be
entitled, like other competing local exchange carriers, to insist upon access to
the existing telecommunications infrastructure by interconnecting our
fiber-optic networks with incumbent local exchange carrier central offices and
other facilities. Under the Telecommunications Act of 1996, incumbent local
exchange carriers must, among other things: (i) interconnect at any technically
feasible point and provide service equal in quality to that provided to others,
(ii) provide unbundled access to network elements, and (iii) provide access to
their poles, ducts, conduits and other rights-of-way.
    
 
   
    Incumbent local exchange carriers must also provide "physical collocation"
for other telecommunications carriers. Physical collocation is an offering by an
incumbent local exchange carriers that enables another telecommunications
carrier to enter the incumbent local exchange carriers premises to install,
maintain and repair its own equipment that is necessary for interconnection or
access to the incumbent local exchange carriers network elements. An incumbent
local exchange carriers allocates reasonable amounts of space to carriers on a
first-come first-served basis. If space limitations or practical or technical
reasons prohibit physical collocation, an incumbent local exchange carriers must
offer "virtual collocation," by which the other carrier may specify incumbent
local exchange carriers equipment to be dedicated to its use and electronically
monitor and control communications terminating in such equipment. We intend, in
some instances, to collocate portions of our network on the premises of certain
incumbent local exchange carriers. Our ability to do this on a cost-effective
basis will depend on the rates, terms and conditions established for
collocation, which will be established by state regulators in arbitration
proceedings and therefore may vary from one state to the next.
    
 
   
    The Federal Communications Commission has responsibility under the
interconnection provisions of the Telecommunications Act of 1996 to determine
what elements of an incumbent local exchange carriers network must be provided
to competitors on an unbundled basis. The Federal Communications Commission has
decided not to declare dark fiber an unbundled network element under these
provisions. This decision is currently subject to petitions for reconsideration
before the Federal Communications Commission. In addition, a federal district
court in North Carolina has interpreted the Telecommunications Act of 1996 to
include dark fiber as a network element.
    
 
   
    In addition, the Federal Communications Commission has announced that state
commissions may decide to add network elements to the Federal Communications
Commission's list of elements that are required to be unbundled by carriers. To
date, state commissions in several states (including New York) have either
refused to require the incumbent local exchange carriers to offer dark fiber to
competitors or have stated that the issue would be addressed at a later time. On
the other hand, other state commissions have found dark fiber to be a network
element and required the incumbent local exchange carriers to offer it on an
unbundled basis to competitive local exchange carriers. Decisions by either the
Federal Communications Commission or additional states to require unbundling of
incumbent local exchange carrier dark fiber or geographic extension of the
ruling of the federal district court in North Carolina could decrease the demand
for our dark fiber, and thereby have an adverse effect on the results of our
operations.
    
 
   
    Incumbent local exchange carriers, competing local exchange carriers and
long distance carriers are subject to additional federal telecommunications
laws. These laws may affect our business by virtue of the interrelationships
that exist among us and many of these regulated telecommunications entities. For
example, the Federal Communications Commission recently issued an order
requiring, among other things, that access charges (fees charged by incumbent
local exchange carriers to long distance carriers for use of local telephone
facilities for the origination and termination of long-distance calls) shift in
part from being usage driven to a fixed flat cost-based structure. The Federal
Communications Commission has also asked for public comments on proposed rules
that would grant incumbent local exchange carriers greater pricing flexibility
for their access services (both switched and non-switched), which may permit the
incumbent local exchange carriers to compete more effectively against some of
    
 
                                       46
<PAGE>
   
our service offerings. While it is not possible to predict the precise effect
the access charge changes will have on our business or financial condition, the
reforms will reduce access charges paid by long distance carriers, likely making
the use of incumbent local exchange carriers facilities by long distance
providers/interexchange carriers more attractive, which could have a material
adverse effect on the use of our fiber optic telecommunications networks by long
distance carriers.
    
 
    STATE
 
   
    The Telecommunications Act of 1996 prohibits state and local governments
from enforcing any law, rule or legal requirement that prohibits or has the
effect of prohibiting any person from providing any interstate or intrastate
telecommunications service. This provision of the Telecommunications Act of 1996
should enable us and our customers to provide telecommunications services in
states that previously prohibited competitive entry.
    
 
   
    However, states retain jurisdiction under the Telecommunications Act of 1996
to adopt regulations necessary to preserve universal service, protect public
safety and welfare, ensure the continued quality of communications services and
safeguard the rights of consumers.
    
 
   
    States continue to determine the rates that incumbent local exchange
carriers can charge for most of their services. They are also responsible for
mediating and arbitrating incumbent local exchange carrier interconnection
arrangements with other carriers if voluntary agreements are not reached.
Accordingly, state involvement in local telecommunications services is
substantial.
    
 
   
    Each state (and the District of Columbia, which is treated as a state for
the purpose of regulation of telecommunications services) has its own statutory
scheme for regulating providers of certain telecommunications-related services
as "common carriers," as "public utilities," or under similar rubrics. As with
the federal regulatory scheme, we believe that the offering of dark fiber
facilities is not subject to this type of regulation in most jurisdictions in
which we currently have or plan to construct facilities. Our offering of
transmission services (as distinct from dark fiber capacity), however, will
likely be subject to regulation in each of these jurisdictions to the extent
that these services are offered for intrastate use. Even though many of our
facilities will be physically intrastate, we anticipate that most customers will
use our facilities and services for the purpose of originating and/or
terminating interstate and foreign communications. Under current Federal
Communications Commission policies, any dedicated transmission service or
facility that is used more than 10% of the time for the purpose of interstate or
foreign communication is subject to Federal Communications Commission
jurisdiction to the exclusion of any state regulation. Therefore, only a small
portion of our business should be subject to state regulation.
    
 
    State regulation of the telecommunications industry is changing rapidly, and
the regulatory environment varies substantially from state to state. Our
subsidiaries are currently authorized to provide intrastate telecommunications
services in California, Connecticut, Delaware, District of Columbia, Illinois,
Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Rhode Island,
Virginia, and Washington, and have an application pending in Oregon. At present,
we do not anticipate that the regulatory requirements to which we will be
subject in the states in which we currently intend to operate will have any
material adverse effect on our operations. These regulations may require, among
other things, that we obtain certification to operate, and that we provide
notification of, or obtain authorization for, certain corporate transactions. We
will incur certain costs to comply with these and other regulatory requirements
such as the filing of tariffs, submission of periodic financial and operational
reports to regulators, and payment of regulatory fees and assessments, including
contributions to state universal service programs. In some jurisdictions, our
pricing flexibility for intrastate services may be limited because of
regulation, although our direct competitors will be subject to similar
restrictions. However, we make no assurances that future regulatory, judicial,
or legislative action will not materially adversely affect us.
 
   
    In response to the 1996 Telecommunications Act of 1996, Bell Atlantic
"unbundled" its local loop in October 1996. As a result, carriers such as us
will be permitted to access Bell Atlantic's existing
    
 
                                       47
<PAGE>
   
wiring infrastructure in buildings on an economical basis, which we believe
enhances the strategic value of the New York/New Jersey network to potential
customers. By virtue of the unbundling, Bell Atlantic must make a significant
portion of its in-house apartment wiring available for $2 per month per
apartment. We expect that the availability of an unbundled local loop will
enable new carriers to enter the residential voice market on a competitive basis
with Bell Atlantic, and these carriers will be potential customers for our
services.
    
 
    LOCAL
 
    In addition to federal and state laws, local governments exercise legal
authority that may impact our business. For example, local governments, such as
the City of New York, typically retain the ability to license public
rights-of-way, subject to the limitation that local governments may not prohibit
persons from providing telecommunications services. Local authorities affect the
timing and costs associated with our use of public rights-of-way. These
regulations may have an adverse effect on our business.
 
    FEDERAL REGULATION OF INTERNATIONAL SERVICE
 
   
    Various regulatory requirements and limitations also will influence our
business as it attempts to enter international markets. Although we have not
fully determined our international business strategy, we have entered into a
50/50 joint venture, ION, with a subsidiary of Racal Telecommunications that
contemplates jointly acquiring and selling international, facilities-based
telecommunications capacity between the U.S. and the United Kingdom and possibly
between the U.S. and other markets. ION is a U.S. international common carrier
subject to U.S. regulation under Title II of the Communications Act of 1934,
and, depending on our specific business plans, it is possible that we will also
become a U.S. international common carrier subject to the same regulations.
Under current Federal Communications Commission rules, international carriers
that do not exercise market power and that are not affiliated with dominant
foreign carriers (carriers possessing market power in their local markets) are
subject to relatively relaxed U.S. regulation as non-dominant international
carriers. As such a non-dominant common carrier, ION is and we would be subject
to, among other policies, the common carrier obligations of nondiscrimination.
In addition, Federal Communications Commission rules prohibit U.S. carriers from
bargaining for special concessions from certain foreign partners. ION is and we
would also be required, under Sections 214 and 203 of the Communications Act of
1934 to obtain authorization and file an international service tariff containing
rates, terms and conditions prior to initiating service. As a non-dominant
carrier, ION has sought and we would be eligible to seek "global" authorization
under Section 214 to operate as facilities-based and/or resale carriers.
International carriers are also subject to certain annual fees and filing
requirements, such as the requirement to file contracts with other carriers,
including foreign carrier agreements, and reports setting forth international
circuit, traffic and revenue data. Failure to obtain an appropriate U.S. license
for international service or the revocation of a license could materially
adversely affect our future operations.
    
 
   
    To the extent that we and ION operate as international common carriers, we
and ION may also be required to comply with the Federal Communications
Commission's International Settlement Policy which defines the permissible
boundaries for U.S. carriers and their foreign correspondents to settle the cost
of terminating each other's traffic over their respective networks. The
International Settlement Policy is designed to eliminate a foreign carrier's
opportunity to discriminate among different U.S. carriers by bargaining for
accounting rates or other terms that benefit the foreign carrier but is
inconsistent with the U.S. public interest. The International Settlement Policy
generally provides that U.S. carriers may only enter into foreign carrier
agreements for the exchange of switched traffic that contain the same accounting
rate and settlement rate (typically one-half of the accounting rate) offered to
all other U.S. carriers. The International Settlement Policy also requires U.S.
carriers to adhere to the principle of proportionate return so that competing
U.S. carriers have comparable opportunities to receive the return traffic that
reduces the marginal cost of providing international service.
    
 
                                       48
<PAGE>
   
    If we provide public switched services over international private lines, we
would be subject to Federal Communications Commission rules governing such
activity rather than to the International Settlement Policy. These rules limit
us from providing switched services over international private lines between the
United States and certain countries and impose certain conditions on carriers
engaging in such activity.
    
 
   
    The Federal Communications Commission continues to refine its international
service rules to promote competition, reflect and encourage liberalization in
foreign countries, and reduce accounting rates toward cost. Among other things,
the Federal Communications Commission has recognized the advent of competition
in the U.K. market by designating the U.K. as a country that offers U.S.
carriers effective competitive opportunities. The Federal Communications
Commission has also amended its rules to reflect the U.S. participation in the
WTO Agreement on Basic Telecommunications Services in which 72 countries have
agreed to eliminate barriers to competition in their markets for basic
telecommunications services. For example, the Federal Communications Commission
has decided to permit U.S. carriers to enter into "flexible" termination
arrangements with carriers in WTO countries, unless such arrangements would not
promote competition. By taking these actions, the Federal Communications
Commission has relaxed or eliminated regulatory limitations on many U.S. carrier
services between the U.S. and the U.K. (as well as between the U.S. and other
members of the WTO). The Federal Communications Commission has also proposed to
eliminate the International Settlements Policy contract requirements for
agreements with certain carriers in certain foreign countries. In addition, the
Federal Communications Commission has established reduced "benchmark" rates for
the amounts U.S. carriers will be allowed to pay foreign carriers for
terminating U.S.-originated traffic. For example, effective as of January 1,
1999, U.S. carriers may ask the Federal Communications Commission to require
that U.S. carriers pay foreign carriers in "high income" countries such as the
United Kingdom no more than $.15 per minute to terminate such calls. Different
rates would apply at different deadlines in different countries depending on the
countries' income level.
    
 
   
    Regulation of the international telecommunications industry is changing
rapidly. We are unable to predict how the Federal Communications Commission will
resolve the various pending international policy issues and the effect of such
resolutions on us.
    
 
REGULATION OF INTERNATIONAL OPERATIONS
 
   
    Our international services would also be subject to regulation in other
countries where we operate. Such regulation, as well as policies and regulations
on the European Union level, may impose separate licensing, service and other
conditions on our international service operations, and these requirements may
have a material adverse impact on Metromedia Fiber Network. The following
discussion is intended to provide a general outline of certain regulations and
current regulatory posture in certain foreign jurisdictions in which we
currently operate or intend to operate, and is not intended as a comprehensive
discussion of such regulations or regulatory posture. Local laws and regulations
differ significantly among these jurisdictions, and, within such jurisdictions,
the interpretation and enforcement of such laws and regulations can be
unpredictable.
    
 
    THE EUROPEAN UNION
 
   
    The European Union was established by the Treaty of Rome and subsequent
treaties. European Union member states are required to implement directives
issued by the European Commission and the European Council by passing national
legislation. The European Commission and European Council have issued a number
of key directives establishing basic principles for the liberalization of the
European Union telecommunications market. This basic framework has been advanced
by a series of harmonization directives, which include the so-called Open
Network Provision directives and the Licensing Directive of April 1997 and the
Interconnection Directive of June 1997, which address the procedures for
granting license authorizations and conditions applicable to such licenses and
the interconnection of networks and the interoperability of services as well as
the achievement of universal service. The Licensing Directive sets out framework
rules for the procedures associated with the
    
 
                                       49
<PAGE>
   
granting of national authorizations for the provision of telecommunications
services and for the establishment or operation of any infrastructure for the
provision of telecommunications services. It distinguishes between "general
authorizations," which should normally be easier to obtain since they do not
require an explicit decision by the national regulatory authority, and
"individual licenses." European Union member states may impose individual
license requirements for the establishment and operation of public
telecommunications networks and for the provision of voice telephony, among
other things. Consequently, ION's operations in the U.K., our operation with
respect to the German network and European network may require that ION or
Metromedia Fiber Network, respectively, be subject to an individual licensing
system rather than to a general authorization in the majority of European Union
member states. In some countries where we operate, we may also be required to
contribute to a fund for the provision of universal service. The United Kingdom
and each other European Union member state in which ION currently conducts or we
intend to conduct our business has a different regulatory regime and such
differences are expected to continue. The requirement that ION or we obtain
necessary approvals varies considerably from country to country.
    
 
    UNITED KINGDOM
 
   
    The U.K. Telecommunications Act of 1984 provides a licensing and regulatory
framework for telecommunications activities in the United Kingdom. The Secretary
of State for Trade and Industry at the Department of Trade and Industry (the
"Secretary of Trade") is responsible for granting licenses under the U.K.
Telecommunications Act of 1984 and for overseeing telecommunications policy,
while the Director General of Telecommunications (the "Director General") and
his office (the Office of Telecommunications ("OFTEL")) are responsible, among
other things, for enforcing the terms of such licenses. Operators wishing to use
their own facilities to provide international services are currently required to
obtain an international facilities license. An international facilities license
licenses the running of telecommunication systems within the U.K. and permits
the licensee to connect U.K. systems to overseas systems, and to offer
international services subject to certain restrictions. ION was awarded an
international facilities license on December 9, 1998. The U.K. Government is
currently consulting on proposals to amend licenses to create one license
authorizing both international and domestic services. The changes are expected
to come into force in 1999 and may result in ION being licensed to provide both
international and domestic services. We have not applied for an international
facilities license or any other authorization for the U.K. portion of our
European network. OFTEL is consulting on which operators will have the right and
obligation to interconnect with the networks of other operators under the regime
established by the Interconnection Directive. OFTEL is expected to announce its
findings shortly. Currently all operators with international facilities licenses
have the right and obligation to interconnect, and this position is not expected
to change. Therefore ION has the right to request and receive interconnection
from all other operators deemed to be entitled to such rights and obligations
(as notified by the Director General) and also the obligation to offer to enter
into an agreement to interconnect at the request of any such operator. The U.K.
Government is currently consulting on changing the obligation to offer to enter
into an agreement to interconnect to an obligation to negotiate with a view to
concluding an interconnection agreement in response to the concern raised by
operators that the current obligation exceeds the requirements of the
Interconnection Directive. The U.K. Government passed the Competition Act 1998
on November 9, 1998, which introduces concurrent powers to the industry specific
regulators and the Director General of Fair Trading for the enforcement of
prohibitions against anti-competitive behavior modeled on Articles 85 and 86 of
the Treaty of Rome. The Act introduces into U.K. legislation prohibitions on the
abuse of a dominant position and anti-competitive agreements, and provides for
third party rights of action, stronger investigative powers, interim measures
and effective enforcement powers. The new rules are expected to come into force
on March 1, 2000. The Act gives the Director General power to exercise
concurrent powers with the Director General of Fair Trading in relation to
"commercial activities connected with telecommunications". The Act will enable
third parties to seek court orders directly against telecommunications operators
who are in breach of the prohibitions contained in the Act and
    
 
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<PAGE>
   
seek damages rather than have to wait for the Director General to issue an
enforcement order. Depending on how these provisions of the Act are implemented,
it may give Metromedia Fiber Network (and its competitors) greater ability to
challenge anti-competitive behavior in the U.K. telecommunications market.
    
 
    GERMANY
 
   
    The German Telecommunications Act of July 25, 1996 liberalized all
telecommunications activities. Under the German Telecommunications Act, voice
telephony was liberalized as of January 1, 1998. The German Telecommunications
Act has been complemented by several Ordinances. The most significant Ordinances
concern license fees, rate regulation, interconnection, universal service,
frequencies and customer protection.
    
 
   
    Under the German regulatory scheme, licenses can be granted within four
license classes. A license is required for operation of transmission lines that
extend beyond the limits of a property and that are used to provide
telecommunications services for the general public. The licenses required for
the operation of transmission lines are divided into 3 infrastructure license
classes: mobile telecommunications (license class 1); satellite (license class
2); and telecommunications services for the general public (license class 3).
Beside the infrastructure licenses, an additional license is required for the
provision of voice telephony services on the basis of self-operated
telecommunications networks (license class 4). A class 4 license does not
include the right to operate transmission lines. According to the License Fees
Ordinance, a nationwide class 4 license costs a onetime fee of DM 3,000,000. The
costs for a territorial class 3 license will be determined by the
Regulierungsbehorde fur Telekommunikation und Post, known as the "RegTP", and is
dependent on the population and the geographical area covered by the territorial
class 3 license. A nationwide territorial class 3 license costs DM 10,600,000.
Licensees that operate transmission lines crossing the boundary of a property
have the right to install transmission lines on, in and above public roads,
squares, bridges and public waterways without payment; however, when installing
transmission lines a planning agreement must be obtained from the relevant
authorities.
    
 
    A company which operates a public telecommunications network has the right
to receive favorable interconnection rates from Deutsche Telekom, as a dominant
carrier. If the company does not agree with the offered rates or Deutsche
Telekom refuses to interconnect for whatever reason, the company can refer the
case to the RegTP which shall decide upon the request for interconnection within
a period of six weeks; if the RegTP decides to extend this deadline, it must at
the latest decide within ten weeks of the request. Whether, and under which
conditions, carrier to carrier operators will receive favorable interconnection
rates or less favorable "special network access rates" from Deutsche Telekom
depends largely on whether they operate a "public telecommunications network."
No definition of "public telecommunications network" has yet been provided. A
public hearing on the regulatory treatment of carrier networks--defined in the
German Telecommunications Act as a telecommunications network to which customers
are not directly connected and which interconnects access networks--and public
telecommunications networks in respect of interconnection has recently been
conducted. The RegTP is expected to publish the outcome of the hearing which
shall include the RegTP's understanding of the constituting elements of a public
telecommunications network shortly. In December 1998, the RegTP presented its
preliminary views on the results of the hearing to an audience of interested
parties in Bonn. According to this presentation, a carrier network constitutes a
"public telecommunications network" if it consists of at least one switch and
more than two connected transmission lines and is used to provide
telecommunications services to the public, irrespective of whether or not
customers are directly or (in the case of a carrier network) indirectly
connected to such network. The RegTP indicated that it did not intend to
establish a minimum number of points of interconnection that are required for
interconnections with Deutsche Telekom. However, the RegTP acknowledged that
carrier networks with few points of interconnection may cause atypical traffic
patterns on Deutsche Telekom's network which may create additional costs to
Deutsche Telekom. The RegTP indicated that Deutsche Telekom will be allowed to
recover its additional costs incurred due to
 
                                       51
<PAGE>
atypical traffic patterns from the operations responsible for such traffic
patterns if and to the extent that Deutsche Telekom can prove such costs. It is
expected that the RegTP's position will become clearer once the RegTP has
published its views in writing in the official journal.
 
   
    In view of this outcome of the public hearing, Deutsche Telekom has
terminated a number of interconnection agreements in December 1998, and has
announced that it will offer new standard interconnection agreements. In the
last few months of 1998, and in view of the public hearing, Deutsche Telekom was
only willing to enter into interim interconnection agreements and only if the
companies requesting interconnection have direct customer access, have a minimum
of eight points of interconnection in the startup phase or commit to establish
this number of points of interconnection as ports for interconnection become
available and upgrade the network to 23 points of interconnection in the initial
phase. The same number of points of interconnection was requested by Deutsche
Telekom in a special network offer for carrier networks. The rates offered by
Deutsche Telekom to carrier network operators were substantially higher than
interconnection rates. In January 1999, Deutsche Telekom presented new drafts
for interconnection agreements which significantly limit the ability of
interconnection partners of Deutsche Telekom to obtain Deutsche Telekom's
services in connection with an interconnection at favorable interconnection
rates. Deutsche Telekom, for example, sets forth requirements to establish
additional points of interconnection if traffic at existing points of
interconnection increases beyond certain thresholds. These drafts are currently
subject to intense discussions between Deutsche Telekom, other
telecommunications companies and representatives of the RegTP. The rates of
Deutsche Telekom's services in conjunction with interconnection and special
network access are subject to regulatory approval; such approval is typically
granted for a limited period of time. Licensed operators are under an obligation
to present their standard terms and conditions to the RegTP. The RegTP may,
based upon certain criteria, decide not to accept these terms and conditions. We
may become subject to universal service financing obligations. Currently, it is
unlikely that the universal service financing system will be implemented in
Germany in the foreseeable future. We have not made any regulatory filings with
respect to the German Network or the German portion of the European Network.
    
 
EMPLOYEES
 
   
    As of January 1, 1999, we employed 126 people. Our employees are not
represented by any labor union. We consider our relationship with our employees
to be good.
    
 
PROPERTIES
 
   
    Our principal properties currently are the New York/New Jersey network and
its component assets. We own substantially all of the communications equipment
required for our business. Our installed fiber optic cable is laid under the
various rights-of-way held by us. Please refer to the section of this Prospectus
entitled "--Build-out of Networks--Rights-of-Way." Our other fixed assets are
located at various leased locations in the geographic areas that we serve. Our
executive and administrative offices are located at our principal office at One
North Lexington Avenue, White Plains, New York. We lease this space (currently
approximately 21,000 square feet) under an agreement that expires in March 2003.
Our sales offices are located at 685 Third Avenue, New York, New York. We lease
this space (approximately 9,670 square feet) under an agreement that expires in
September 2003. We lease additional space (currently 8,710 square feet) at 60
Hudson Street, New York, New York, from Hudson Telegraph Associates under an
agreement that expires in March 2010. We also lease 2,665 square feet of sales
space in Malvern, Pennsylvania, and 3,438 square feet of sales space in McLean,
Virginia.
    
 
LEGAL PROCEEDINGS
 
   
    On or about October 20, 1997, Vento & Company of New York, LLC commenced an
action against Metromedia Fiber Network, Stephen A. Garofalo, Peter Silverman,
the law firm of Silverman, Collura, Chernis & Balzano, P.C., Peter Sahagen,
Sahagen Consulting Group of Florida (collectively, the "Sahagen Defendants") and
Robert Kramer, Birdie Capital Corp., Lawrence Black, Sterling Capital
    
 
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<PAGE>
   
LLC, Penrush Limited, Needham Capital Group, Arthur Asch, Michael Asch and
Ronald Kuzon (the "Kramer Defendants") in the United States District Court for
the Southern District of New York (No. 97 CIV 7751). On or about May 29, 1998,
Vento & Company filed an amended complaint. In its complaint, as amended, Vento
& Company alleges four causes of action in connection with its sale of 900,000
shares (not adjusted for subsequent stock splits) of Class A Common Stock to
Peter Sahagen and the Kramer Defendants on January 13, 1997. The four causes of
action include: (i) violation of Section 10(b) of the Securities Exchange Act of
1934 and Rule 10b-5 promulgated under such Act; (ii) fraud and fraudulent
concealment; (iii) breach of fiduciary duty; and (iv) negligent
misrepresentation and omission. On the first and second causes of action, Vento
& Company is seeking, among other things, rescission of the Vento & Company
sale, or alternatively, damages in an amount which we cannot currently ascertain
but believe to be in excess of $36 million, together with interest. On the third
and fourth causes of action, Vento & Company is seeking damages in an amount
which we cannot currently ascertain but believe to be in excess of $36 million,
together with interest. Vento & Company is also seeking punitive damages in the
amount of $50 million, reasonable legal fees and the cost of this action. All
the defendants, including Metromedia Fiber Network and Stephen A. Garofalo, have
moved to dismiss Vento and Company's amended complaint.
    
 
   
    On or about June 12, 1998, Claudio E. Contardi commenced an action against
Peter Sahagen, Sahagen Consulting Group of Florida and Metromedia Fiber Network
in the United States District Court for the Southern District of New York (No.
98 CIV 4140). Mr. Contardi alleges a cause of action for, among other things,
breach of a finder's fee agreement entered into between Mr. Sahagen and Mr.
Contardi on or about November 14, 1996 and breach of an implied covenant of good
faith and fair dealing contained in the finder's fee agreement. Mr. Contardi is
seeking, among other things, a number of shares of Metromedia Fiber Network
which we cannot currently ascertain but believe to be approximately 225,000
shares (calculated as of the date on which the complaint was filed) or damages
in an amount which we cannot currently ascertain but believe to be approximately
$4.9 million (calculated as of the date on which the complaint was filed) and
all costs and expenses incurred by him in this action. We have filed an answer
to the complaint and have raised affirmative defenses.
    
 
   
    We intend to vigorously defend both these actions because we believe that we
acted appropriately in connection with the matters at issue in these two cases.
However, we cannot assure you that we will not determine that the advantages of
entering into a settlement outweigh the risk and expense of protracted
litigation or that ultimately we will be successful in defending against these
allegations. If we are unsuccessful in defending against these allegations, an
award of the magnitude being sought in the Vento & Company litigation would have
a material adverse effect on our financial condition or results of operations.
    
 
   
    In addition, we are subject to various claims and proceedings in the
ordinary course of business. Based on information currently available, we
believe that none of such current claims, or proceedings, individually or in the
aggregate, including the Vento & Company litigation and the Contardi litigation,
will have a material adverse effect on our financial condition or results of
operations, although we can make no assurances in this regard.
    
 
                                       53
<PAGE>
                                   MANAGEMENT
 
   
    The directors and executive officers of Metromedia Fiber Network and their
ages as of January 1, 1999 are as follows:
    
 
<TABLE>
<CAPTION>
NAME                                                       AGE                          POSITION HELD
- -----------------------------------------------------      ---      -----------------------------------------------------
<S>                                                    <C>          <C>
Stephen A. Garofalo..................................          47   Chairman of the Board and Chief Executive Officer
Howard M. Finkelstein................................          45   President, Chief Operating Officer and Director
Vincent A. Galluccio.................................          52   Senior Vice President and Director
Gerard Benedetto.....................................          41   Vice President--Chief Financial Officer
Charlotte G. Denenberg...............................          51   Vice President--Chief Technology Officer
Nicholas M. Tanzi....................................          40   Vice President--Sales
Silvia Kessel........................................          48   Executive Vice President and Director
John W. Kluge........................................          84   Director
David Rockefeller....................................          83   Director
Stuart Subotnick.....................................          56   Director
Arnold L. Wadler.....................................          55   Executive Vice President, General Counsel, Secretary
                                                                    and Director
Leonard White........................................          59   Director
</TABLE>
 
   
    STEPHEN A. GAROFALO founded the Company in April 1993, and has been serving
as Chairman of the board of directors since Metromedia Fiber Network's
inception. Mr. Garofalo served as Chief Executive Officer since October 1996, as
President from 1993 to 1996 and as Secretary from 1993 to 1997. From 1979 to
1993 Mr. Garofalo served as President and Chief Executive Officer of F. Garofalo
Electric Co., Inc., an electrical contractor.
    
 
   
    HOWARD M. FINKELSTEIN has been President, Chief Operating Officer and a
Director of Metromedia Fiber Network since April 1997. Prior to joining
Metromedia Fiber Network, Mr. Finkelstein was employed by various affiliates of
Metromedia Company for 16 years. His most recent position was as Executive Vice
President and Chief Operating Officer of Metromedia International
Telecommunications, Inc. From 1984 to 1993, Mr. Finkelstein served as President
of Metromedia Communications Corporation, a national long distance
telecommunications carrier. In addition, Mr. Finkelstein served as Executive
Vice President and Chief Operating Officer of Metromedia Restaurant Group from
1993 to 1995. Mr. Finkelstein is a Director of Multimedia Medical Systems,
Incorporated, a privately held company.
    
 
   
    VINCENT A. GALLUCCIO has been a Director of Metromedia Fiber Network since
February 1997 and has served as President of ION since February 1998 and as a
Senior Vice President of Metromedia Fiber Network since December 1995. From
January 1992 to October 1994, Mr. Galluccio was employed by British
Telecommunications plc, as a global sales manager for network outsourcing
operations. Prior to joining British Telecommunications plc, Mr. Galluccio spent
25 years with International Business Machines Corporation in various sales,
marketing and business development positions and was involved in both domestic
and world trade assignments.
    
 
    GERARD BENEDETTO has been Vice President--Chief Financial Officer since
February 1998. From July 1995 to January 1998, he was Vice President--Chief
Accounting Officer at Metromedia International Telecommunications, Inc. From
October 1993 to July 1995 he was Vice President--Chief Financial Officer at
Metromedia Restaurant Group. From February 1985 to October 1993, he was Vice
President--Chief Financial Officer at Metromedia Communications Corporation.
 
   
    CHARLOTTE G. DENENBERG has served as Vice President--Chief Technology
Officer since December 1998. Prior to joining Metromedia Fiber Network, Ms.
Denenberg was employed by Southern New
    
 
                                       54
<PAGE>
England Telecommunications Corporation ("SNET"), since 1987 in a variety of
positions. Ms. Denenberg held the position of Chief Technology Officer for SNET
from 1994 to November 1998. Before SNET, Ms. Denenberg was employed by ITT
Corporation as Director--Technology Evaluation.
 
    NICHOLAS M. TANZI has been Vice President--Sales since August 1997. From
March 1995 to July 1997, he served as Vice President, Enterprise Networks
Division at Fujitsu Business Communications Systems. From April 1993 to February
1995, Mr. Tanzi was Director of Sales, Eastern Region at Asante Technologies
Inc. Mr. Tanzi was employed in various capacities from November 1979 through
October 1993 at Digital Equipment Corporation.
 
   
    SILVIA KESSEL has served as a Director of Metromedia Fiber Network since
July 1997 and as Executive Vice President since October 1997. Ms. Kessel has
served as Chief Financial Officer and Treasurer of Metromedia International
Group, Inc. since 1995 and Executive Vice President of Metromedia International
Group since 1996. In addition, Ms. Kessel served as Executive Vice President of
Orion Pictures Corporation, a motion picture production and distribution
company, from January 1993 through July 1997, Senior Vice President of
Metromedia Company since 1994 and President of Kluge & Company since January
1994. Prior to that time, Ms. Kessel served as Senior Vice President and a
Director of Orion Pictures from June 1991 to November 1992 and Managing Director
of Kluge & Company from April 1990 to January 1994. Ms. Kessel is Executive Vice
President and a member of the board of directors of Big City Radio, Inc., a
company listed on the American Stock Exchange that operates radio stations in
New York, Los Angeles and Chicago, and of Metromedia International Group.
    
 
   
    JOHN W. KLUGE has been a Director of Metromedia Fiber Network since July
1997. Mr. Kluge has been the President and Chairman of Metromedia Company and
its predecessor-in-interest, Metromedia, Inc., for over five years. Mr. Kluge
has been the Chairman of the Board of Metromedia International Group since 1995.
In addition, Mr. Kluge was Chairman of the board of directors and a Director of
Orion Pictures from 1992 until July 1997. He also serves as a Director of Conair
Corporation and Occidental Petroleum Corporation.
    
 
   
    DAVID ROCKEFELLER has served as a Director of Metromedia Fiber Network since
October 1997. He currently serves as Chairman of The Chase Manhattan Bank's
International Advisory Committee, as Chairman of Rockefeller Center Properties,
Inc. (since 1995) and as a Director of Rockefeller & Co., Inc. (since 1994), a
privately owned investment management firm. From 1961 to 1981, Mr. Rockefeller
served as Chairman of The Chase Manhattan Corporation and The Chase Manhattan
Bank, N.A. From 1981 to 1995, he served as Chairman of Rockefeller Group, Inc.
    
 
   
    STUART SUBOTNICK has been a Director of Metromedia Fiber Network since July
1997. Mr. Subotnick has been the Vice Chairman of the board of directors of
Metromedia International Group since 1995 and President and Chief Executive
Officer of Metromedia International Group since December 1996. In addition, Mr.
Subotnick served as Vice Chairman of the board of directors of Orion Pictures
from 1992 until July 1997. Mr. Subotnick has served as Executive Vice President
of Metromedia Company and its predecessor-in-interest, Metromedia, Inc., for
over five years. Mr. Subotnick has served as Vice Chairman of Metromedia
International Group since November 1995 and President and Chief Executive
Officer of Metromedia International Group since November 1996. Mr. Subotnick is
also a Director of Carnival Cruise Lines, Inc. and Chairman of the board of
directors of Big City Radio.
    
 
   
    ARNOLD L. WADLER has served as Executive Vice President, General Counsel and
Secretary of Metromedia Fiber Network since October 1997 and has served as a
Director of Metromedia Fiber Network since July 1997. Mr. Wadler has served as
Executive Vice President, General Counsel and Secretary of Metromedia
International Group since August 29, 1996 and, from November 1, 1995 until that
date, as Senior Vice President, General Counsel and Secretary of Metromedia
International Group and as the Executive Vice President, General Counsel,
Secretary and Director of Big City Radio since
    
 
                                       55
<PAGE>
   
December 1997. In addition, Mr. Wadler serves as a Director of Metromedia
International Group and has served as a Director of Orion Pictures from 1991
until July 1997 and as Senior Vice President, Secretary and General Counsel of
Metromedia Company, and its predecessor-in-interest, Metromedia, Inc., for over
five years.
    
 
   
    LEONARD WHITE has served as a Director of Metromedia Fiber Network since
October 1997. Mr. White has served as President and Chief Executive Officer of
Rigel Enterprises since July 1997. Mr. White served as President and Chief
Executive Officer of Orion Pictures from 1992 until 1997 and as President and
Chief Executive Officer of Orion Home Entertainment Corporation from 1987 to
1992. Mr. White also serves as a Director of Metromedia International Group, Big
City Radio and American Film Technologies, Inc.
    
 
BOARD OF DIRECTORS
 
   
    There are presently nine members of the board of directors of Metromedia
Fiber Network. Holders of the Class B Common Stock are entitled to elect 75% of
the board of directors and holders of the Class A Common Stock are entitled to
vote as a separate class to elect the remaining directors. Currently six of the
nine directors are nominees of the holders of Class B Common Stock and as a
result holders of the Class B Common Stock are entitled to fill three vacancies
on the board of directors. Members of each class of directors will hold office
until their successors are elected and qualified. The directors are elected by a
plurality vote of all votes cast at each annual meeting of stockholders of
Metromedia Fiber Network entitled to vote for such directors. The directors hold
office for a one-year term.
    
 
COMPENSATION OF DIRECTORS
 
   
    During 1998, each director of Metromedia Fiber Network who was not an
officer, employee or affiliate of Metromedia Fiber Network will be entitled to
receive a $20,000 annual retainer plus a separate attendance fee of $1,200 for
each meeting of the board of directors attended a in person or $500 for each
meeting of the board of directors in which this non-employee director
participated by conference telephone call. Members of committees of the board of
directors are paid $500 for each meeting attended. In addition, Metromedia Fiber
Network's 1998 Incentive Stock Plan entitles any non-employee director who first
serves on the board of directors after the adoption of the 1998 Incentive Stock
Plan to receive awards under such plan of 20,000 shares of Class A Common Stock,
each having an exercise price equal to the fair market value of a share of Class
A Common Stock on the date of grant. Awards to non-employee directors under the
1998 Incentive Stock Plan will be aggregated with awards under the 1997
Incentive Stock Plan so that total awards under each plan will not exceed 20,000
shares of Class A Common Stock.
    
 
   
    Non-employee directors who meet the criteria for "outside director" under
Section 162(m) of the Internal Revenue Code are entitled to receive options to
purchase 20,000 shares of Metromedia Fiber Network's Class A Common Stock under
Metromedia Fiber Network's 1997 Incentive Stock Plan. Under the 1997 Incentive
Stock Plan, each non-employee Director who was a director of Metromedia Fiber
Network on October 28, 1997 was granted an option to purchase 20,000 shares of
Metromedia Fiber Network's common stock at an exercise price of $4.00, the price
of the Class A Common Stock on the date of our initial public offering.
    
 
   
    The 1997 Incentive Stock Plan further provides that each person who becomes
a non-employee outside director of Metromedia Fiber Network after October 28,
1997 will receive an option to purchase 20,000 shares of Metromedia Fiber
Network's Class A Common Stock on the day such director is elected as a
director, at an exercise price equal to the closing price of the common stock on
the trading day preceding such director's election. Options granted to these
non-employee outside directors fully vest and become exercisable as to all
20,000 shares on the date of grant.
    
 
                                       56
<PAGE>
   
    In addition, on August 20, 1997, Metromedia Fiber Network granted to each of
Mr. Kluge and Mr. Subotnick options to purchase 1,014,000 shares of Class A
Common Stock at an exercise price of $.49 per share and to each of Mr. Wadler
and Ms. Kessel options to purchase 202,800 shares of Class A Common Stock at an
exercise price of $.49 per share.
    
 
EXECUTIVE COMPENSATION
 
   
    The following table provides you with information on the compensation
awarded to, earned by or paid to our Chief Executive Officer and our four other
most highly compensated executive officers during the fiscal years ended
December 31, 1998, December 31, 1997 and December 31, 1996, for services
rendered in all capacities to Metromedia Fiber Network and our subsidiaries. The
persons listed in the table below are referred to as the "named executive
officers."
    
 
   
<TABLE>
<CAPTION>
                                                                                         LONG TERM
                                                ANNUAL COMPENSATION                 COMPENSATION AWARDS
                                     -----------------------------------------   -------------------------
<S>                                  <C>   <C>         <C>        <C>            <C>              <C>
                                                                                  NUMBER OF
                                                                                    SHARES          ALL
                                                                  OTHER ANNUAL    UNDERLYING       OTHER
                                                                  COMPENSATION      STOCK         COMPENS.
NAME AND PRINCIPAL POSITION          YEAR  SALARY($)   BONUS($)      ($)(1)       OPTIONS(2)        ($)
- -----------------------------------  ----  ---------   --------   ------------   ------------     --------
Stephen A. Garofalo................  1998    328,385    100,000      23,301           --            --
  Chairman and Chief                 1997    295,000     50,000      14,157         1,521,000(3)    --
  Executive Officer                  1996    225,000      --         --               --            --
 
Howard M. Finkelstein..............  1998    321,462    100,000      24,074           --            --
  President and Chief                1997    196,756     50,000      11,769         6,084,000(5)    --
  Operating Officer(4)               1996     --          --         --               --            --
 
Vincent A. Galluccio...............  1998    183,400     15,000       1,673           150,000(6)    --
  Senior Vice President              1997    181,522      --         --             1,090,920(7)    --
                                     1996    127,087      --         --               --            --
 
Gerard Benedetto...................  1998    181,423      --          3,355           550,000(9)    --
  Vice President--Chief              1997     --          --         --               --            --
  Financial Officer(8)               1996     --          --         --               --            --
 
Nicholas M. Tanzi..................  1998    158,000     65,000       2,819           150,000(6)    --
  Vice President--Sales(10)          1997     --          --         --               360,840(11)   --
                                     1996     --          --         --               --            --
</TABLE>
    
 
- ------------------------
 
(1) Includes amounts paid as automobile allowance, insurance premiums and 401(k)
    matching funds.
 
   
(2) This information gives effect to our stock splits.
    
 
   
(3) Includes presently exercisable options to purchase 1,521,000 shares of Class
    A Common Stock at an exercise price of $.49 per share.
    
 
   
(4) Officer was hired by Metromedia Fiber Network during 1997, thus preceding
    year's compensation is not applicable.
    
 
   
(5) Includes presently exercisable options to purchase 6,084,000 shares of Class
    A Common Stock at an exercise price of $.49 per share.
    
 
   
(6) Includes options to purchase 150,000 shares of Class A Common Stock at an
    exercise price of $10.50 per share that will become exercisable ratably over
    a four year period commencing August 31, 1999.
    
 
                                       57
<PAGE>
   
(7) Includes presently exercisable options to purchase 640,920 shares of Class A
    Common Stock at an exercise price of $.49 per share and the options to
    purchase 150,000 shares of Class A Common Stock which the officer exercised
    during 1998. Also, includes options to purchase 300,000 shares of Class A
    Common Stock at an exercise price of $4.00 per share that will become
    exercisable ratably over a four year period commencing October 28, 1998.
    
 
   
(8) Officer was hired by Metromedia Fiber Network during 1998, thus preceeding
    years' compensation is not applicable.
    
 
   
(9) Includes options to purchase 400,000 and 150,000 shares of Class A Common
    Stock at an exercise price of $3.88 and $10.50 per share that will become
    exercisable ratably over a four year period commencing January 6, 1999 and
    August 31, 1999, respectively.
    
 
   
(10) Officer was hired by Metromedia Fiber Network during 1997, thus preceding
    year's compensation is not applicable. Compensation information for 1997 is
    omitted because aggregate compensation during such fiscal year was less than
    $100,000.
    
 
(11) Includes presently exercisable options to purchase 60,840 shares of Class A
    Common Stock at an exercise price of $1.91 per share and options to purchase
    300,000 shares of Class A Common Stock at an exercise price of $4.00 per
    share that will become exercisable ratably over a four year period
    commencing October 28, 1998.
 
   
    During 1998 and 1997, Mr. Wadler and Ms. Kessel, each of whom serves as an
executive officer of Metromedia Fiber Network , were employed and paid by
Metromedia Company pursuant to a management agreement with Metromedia Company
dated as of January 2, 1998. Please refer to the section in this Prospectus
entitled "Certain Relationships and Related Transactions--Recent
Transactions--Management Agreement." Metromedia Fiber Network did not pay any
other amounts to the named executive officers during 1998 or 1997.
    
 
EMPLOYMENT AGREEMENTS
 
   
    We have entered into employment agreements with each of the following named
executive officers.
    
 
   
    GAROFALO EMPLOYMENT AGREEMENT. Mr. Garofalo's employment agreement, dated as
of February 26, 1997, has a five year term. It provides Mr. Garofalo a base
salary of $295,000 for the first year, $335,000 for the second year, $375,000
for the third year, $415,000 for the fourth year and $455,000 for the fifth
year. Mr. Garofalo is also entitled to receive an annual incentive bonus to be
determined by the compensation committee of the board of directors. The
incentive bonus will not be less than $100,000 per year. Mr. Garofalo's
employment agreement also provides for other employee benefits such as a car
allowance, life insurance, health care and certain disability and death
benefits. In addition, Mr. Garofalo was granted options to purchase 1,521,000
shares of Class A Common Stock at an exercise price of $.49 per share. These
options are immediately exercisable and expire 10 years from their grant. We
registered the shares of Class A Common Stock underlying the options under the
Securities Act upon the consummation of our initial public offering.
    
 
   
    Except in the case of disability, we may terminate Mr. Garofalo's employment
only for cause upon which termination Mr. Garofalo will have no right to receive
any compensation or benefit from us. If the agreement is terminated without
cause, or if Mr. Garofalo terminates employment for good reason, we will be
obligated to pay Mr. Garofalo an amount equal to the greater of (i) his monthly
base salary as then in effect multiplied by the number of months remaining in
the term of his employment as of such termination date and (ii) $1,000,000.
"Good reason" includes (i) a reduction in the nature or scope of Mr. Garofalo's
titles, authorities, powers, duties or responsibilities; (ii) a change in the
method or formula for determining the bonus which results in a decrease in the
amount of bonus payable to Mr. Garofalo; (iii) the removal of Mr. Garofalo as a
member of the board of directors, unless such removal occurs after termination
of Mr. Garofalo's employment for cause; (iv) a sale of all or
    
 
                                       58
<PAGE>
   
substantially all of the ownership interests or assets of the Company or a
merger or consolidation of Metromedia Fiber Network with any other corporation;
(v) a change in control of Metromedia Fiber Network, defined as any person or
entity becoming a beneficial owner as defined in Rule 13d-3 of the Securities
Exchange Act of 1934 directly or indirectly of securities of Metromedia Fiber
Network representing 50% or more of the combined voting power of Metromedia
Fiber Network's then outstanding securities; or (vi) a material breach by
Metromedia Fiber Network of its affirmative or negative covenants or
undertakings in the employment agreement and a failure to remedy such breach
within 15 days. Pursuant to the agreement, Mr. Garofalo has agreed not to
compete with Metromedia Fiber Network for a period of one year following
termination of the agreement. During such non-compete period, Mr. Garofalo will
be entitled to receive an amount equal to his base salary as in effect on the
date of termination so long as the agreement was not terminated prior to the
expiration of the term by either party.
    
 
   
    FINKELSTEIN EMPLOYMENT AGREEMENT. Mr. Finkelstein's employment agreement,
dated as of April 30, 1997, has a three year term. It provides Mr. Finkelstein
with a base salary of $295,000 for the first year, $335,000 for the second year
and $375,000 for the third year. Mr. Finkelstein is also entitled to receive an
annual incentive bonus to be determined by the compensation committee of the
board of directors. The incentive bonus will not be less than $100,000 for each
year. Mr. Finkelstein's employment agreement also provides for other employee
benefits such as a car allowance, life insurance, health care, and certain
disability and death benefits. In addition, Mr. Finkelstein was granted options
to purchase 6,084,000 shares of Class A Common Stock at an exercise price of
$.49 per share, which options are immediately exercisable and expire 10 years
from their grant. We registered such shares of Class A Common Stock under the
Securities Act on Form S-8 upon the consummation of our initial public offering.
    
 
   
    Except in the case of disability, we may terminate Mr. Finkelstein's
employment only for cause upon which termination Mr. Finkelstein will have no
right to receive any compensation or benefit from us. If the agreement is
terminated without cause or if Mr. Finkelstein terminates employment for good
reason, we will be obligated to pay to Mr. Finkelstein his base salary, bonus
and benefits that are accrued and unpaid as of the date of termination as well
as an amount equal to one and a half times his base salary as then in effect.
"Good reason" includes (i) a reduction in the nature or scope of Mr.
Finkelstein's titles, authorities, powers, duties or responsibilities; (ii) a
change in the method or formula for determining the bonus which results in a
decrease in the amount of bonus payable to Mr. Finkelstein; (iii) the removal of
Mr. Finkelstein as a member of the board of directors, unless such removal
occurs after termination of Mr. Finkelstein's employment for cause; (iv) a sale
of all or substantially all of the ownership interests or assets of Metromedia
Fiber Network or a merger or consolidation of Metromedia Fiber Network with any
other corporation; (v) a change in control of Metromedia Fiber Network, defined
as any person or entity (other than Mr. Garofalo) becoming a beneficial owner as
defined in Rule 13d-3 of the Securities Exchange Act of 1934 directly or
indirectly of securities of Metromedia Fiber Network representing 50% or more of
the combined voting power of Metromedia Fiber Network's then outstanding
securities; or (vi) a material breach by Metromedia Fiber Network of its
affirmative or negative covenants or undertakings in the employment agreement
and a failure to remedy such breach within 15 days. Pursuant to the agreement,
Mr. Finkelstein has agreed not to compete with Metromedia Fiber Network for a
period of one year following termination of the agreement. During such
non-compete period, Mr. Finkelstein will be entitled to receive an amount equal
to his base salary as in effect on the date of termination so long as the
agreement was not terminated prior to the expiration of the term by either
party.
    
 
   
    GALLUCCIO EMPLOYMENT AGREEMENT.  Mr. Galluccio's employment agreement, dated
as of August 31, 1998, has a one year term. It provides Mr. Galluccio with a
base salary of $183,400. Mr. Galluccio is also entitled to receive an annual
incentive bonus, which is dependent upon Metromedia Fiber Network's performance,
to be determined by the compensation committee of the
    
 
                                       59
<PAGE>
   
board of directors. If approved by the compensation committee, the incentive
bonus has a target of 20% of Mr. Galluccio's base salary. Mr. Galluccio's
employment agreement also provides for other employee benefits such as the right
to participate in all group health and insurance programs. In addition, Mr.
Galluccio was granted options to purchase 150,000 shares of Class A Common Stock
at an exercise price of $10.50 per share. These shares have been registered
under the Securities Act on Form S-8.
    
 
   
    Except in the case of disability or a change of control, we may terminate
Mr. Galluccio's employment only for cause upon which termination Mr. Galluccio
will have no right to receive any compensation or benefit from us. If Mr.
Galluccio's employment is terminated for any reason other than for cause or in
the event that there is a change of control of Metromedia Fiber Network and Mr.
Galluccio is requested in connection with such change of control to perform his
duties under this agreement on a regular, full-time basis at a location further
than 75 miles from Mr. Galluccio's current principal office location, Mr.
Galluccio, in his sole and absolute discretion, may deem this agreement to be
terminated by Metromedia Fiber Network without cause. Upon such termination, Mr.
Galluccio will be entitled to receive his base salary for the remaining term of
his employment agreement, all previously earned and accrued entitlements and
benefits from us and our employee benefit plans and an amount equal to 25% of
Mr. Galluccio's base salary. Under his employment agreement, Mr. Galluccio has
agreed not to compete with Metromedia Fiber Network or any affiliated company
for a period of two years following the termination of the agreement.
    
 
   
    BENEDETTO EMPLOYMENT AGREEMENT. Mr. Benedetto's employment agreement, dated
as of August 31, 1998, has a three and one-half year term. It provides Mr.
Benedetto with a minimum base salary of $200,000 for each year. Mr. Benedetto is
also entitled to receive an annual incentive bonus, which is dependent upon
Metromedia Fiber Network's performance, to be determined by the compensation
committee of the board of directors. If approved by the compensation committee,
the incentive bonus has a target of 20% of Mr. Benedetto's base salary. Mr.
Benedetto's employment agreement also provides for other employee benefits such
as the right to participate in all group health and insurance programs. In
addition, Mr. Benedetto was granted options to purchase 150,000 shares of Class
A Common Stock at an exercise price of $10.50 per share. These shares have been
registered under the Securities Act on Form S-8.
    
 
   
    Except in the case of disability or a change of control, we may terminate
Mr. Benedetto's employment only for cause upon which termination Mr. Benedetto
will have no right to receive any compensation or benefit from us. If Mr.
Benedetto's employment is terminated for any reason other than for cause or in
the event that there is a change of control of Metromedia Fiber Network and Mr.
Benedetto is requested in connection with such change of control to perform his
duties under this agreement on a regular, full-time basis at a location further
than 75 miles from Mr. Benedetto's current principal office location, Mr.
Benedetto, in his sole and absolute discretion, may deem this agreement to be
terminated by Metromedia Fiber Network without cause. Upon such termination, Mr.
Benedetto will be entitled to receive his base salary for the remaining term of
his employment agreement, all previously earned and accrued entitlements and
benefits from us and our employee benefit plans and an amount equal to 25% of
Mr. Benedetto's base salary. Under his employment agreement, Mr. Benedetto has
agreed not to compete with Metromedia Fiber Network or any affiliated company
for a period of two years following termination of the agreement.
    
 
   
    TANZI EMPLOYMENT AGREEMENT.  Mr. Tanzi's employment agreement, dated as of
August 31, 1998, has a two year term. It provides Mr. Tanzi with a minimum base
salary of $175,000 for each year. Mr. Tanzi is also entitled to receive an
annual incentive bonus, which is dependent upon Metromedia Fiber Network's
performance, to be determined by the compensation committee of the board of
directors. If approved by the compensation committee, the incentive bonus has a
target of 40% of Mr. Tanzi's base salary. Mr. Tanzi's employment agreement also
provides for other employee benefits such as the right to participate in all
group health and insurance programs. In addition, Mr. Tanzi was granted options
to
    
 
                                       60
<PAGE>
purchase 150,000 shares of Class A Common Stock at an exercise price of $10.50
per share. These shares have been registered under the Securities Act on Form
S-8.
 
   
    Except in the case of disability or change of control, we may terminate Mr.
Tanzi's employment only for cause upon which termination Mr. Tanzi will have no
right to receive any compensation or benefit from us. If Mr. Tanzi's employment
is terminated for any reason other than for cause or in the event that there is
a change of control of Metromedia Fiber Network and Mr. Tanzi is requested in
connection with such change of control to perform his duties under this
agreement on a regular, full-time basis at a location further than 75 miles from
Mr. Tanzi's current principal office location, Mr. Tanzi, in his sole and
absolute discretion, may deem this agreement to be terminated by Metromedia
Fiber Network without cause. Upon such termination, Mr. Tanzi will be entitled
to receive his base salary for the remaining term of his employment agreement,
all previously earned and accrued entitlements and benefits from us and our
employee benefit plans and an amount equal to 25% of Mr. Tanzi's base salary.
Under his employment agreement, Mr. Tanzi has agreed not to compete with
Metromedia Fiber or any affiliated company for a period of two years following
termination of the agreement.
    
 
INDEMNIFICATION AGREEMENTS
 
   
    We have entered into indemnification agreements with certain officers and
directors. The indemnification agreements provide for indemnification of such
directors and officers to the fullest extent authorized or permitted by law. The
indemnification agreements also provide that (i) we will advance all expenses
incurred by the director or officer in defending certain litigation, (ii) we
will appoint in certain circumstances an independent legal counsel to determine
whether the director or officer is entitled to indemnification and (iii) we will
continue to maintain directors' and officers' liability insurance (which
currently consists of $25.0 million of primary coverage).
    
 
                                       61
<PAGE>
                 CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
 
HISTORICAL TRANSACTIONS
 
   
    As of December 31, 1996, we had outstanding approximately $4.9 million of
indebtedness due to US ONE Communications of New York, Inc., a lessee of our
dark fiber, which was personally guaranteed by Stephen A. Garofalo. On April 30,
1997, upon consummation of the Metromedia Investment (as described below),
$1,370,000 of the indebtedness was repaid in cash from proceeds of the
Metromedia Investment while the remainder was converted into a prepaid lease
payment to us. Therefore, there is no such indebtedness currently outstanding.
    
 
   
    In February, 1996, we entered into a settlement agreement with Howard Katz,
Metromedia Fiber Network former Chief Financial Officer, and Realprop Capital
Corp., an affiliate of Mr. Katz, in connection with the termination of Mr.
Katz's employment with us. Pursuant to the settlement agreement, we agreed to
pay Mr. Katz approximately $940,000 over a period of five years, including
$90,000 per year pursuant to a consulting agreement. Under the consulting
agreement, Realprop Capital was to provide consulting services relating to
Katz's knowledge and understanding of transactions and the conduct of business
in which we engaged and to such other areas of consultation as Katz and we
mutually agreed upon. On November 12, 1996, Howard Katz, Lauren Katz, Stephen
Katz and Realprop Capital (collectively, the "Katz group") entered into
operational agreement with Peter Sahagen, at the time Acting Vice
Chairman--Finance of Metromedia Fiber Network. The purchase agreement granted
Mr. Sahagen the right to purchase an aggregate of 1,058,524 shares of Class A
Common Stock and an option to purchase warrants for 831,532 shares of Class A
Common Stock for an aggregate purchase price of $640,000. In conjunction with
the purchase agreement, in a letter agreement dated December 10, 1996, Howard
Katz and Realprop Capital agreed to release us from all liabilities and
obligations arising out of the settlement agreement, and to reduce the term of
the $90,000 per year consulting agreement from five years to three years. On
February 11, 1997, Mr. Sahagen entered into a letter agreement with us
acknowledging that he was acting as nominee for us with respect to the purchase
agreement and assigned to us all of his rights, title and interest in and to the
purchase agreement. We agreed to reimburse Mr. Sahagen for $25,000 in payments
made to Mr. Katz for extending Mr. Sahagen's right to purchase the securities.
On February 11, 1997, we entered into an agreement with the Katz group, under
which we purchased the securities for $640,000 and confirmed that the consulting
agreement may be terminated by us after three years of its term had concluded.
The purchase price was funded with a portion of the proceeds of the Metromedia
Loan (as described below). In March, 1998, we entered into an amendment,
settlement and release agreement with the Katz group and Evelyn Katz in
connection with the foregoing.
    
 
   
    On April 15, 1996, we entered into an employment agreement with Gerald Vento
under which Mr. Vento would serve as Chief Executive Officer of Metromedia Fiber
Network. On the same day, we entered into a stock purchase agreement and a
consulting agreement with Vento & Company of New York, LLC. Under the stock
purchase agreement, we issued 6,084,000 shares of Class A Common Stock to Vento
& Company as consideration for prior services provided by Vento & Company. On
October 9, 1996, we entered into a settlement agreement with Mr. Vento and Vento
& Company. In this settlement agreement, (i) we agreed to terminate Mr. Vento's
employment agreement, (ii) Vento & Company agreed to sell to Stephen A. Garofalo
5,475,600 shares of Class A Common Stock and (iii) we agreed to pay $112,500 to
Vento & Company on behalf of Mr. Vento. On January 3, 1997, Mr. Garofalo
assigned his right to purchase the Vento shares to Mr. Sahagen. On January 13,
1997, Mr. Sahagen and other parties purchased the Vento shares for $425,000.
Please refer to the section of this Prospectus entitled "Business--Legal
Proceedings."
    
 
   
    On October 28, 1996, the Knobel 1995 Children's Investment Trust granted to
Stephen A. Garofalo an option to purchase 1,599,556 shares of Class A Common
Stock for an aggregate purchase price of $500,000. By letter dated December 3,
1996, the option was amended to reduce the number of
    
 
                                       62
<PAGE>
option shares to 1,295,356. Mr. Garofalo thereafter assigned this option to us.
On February 11, 1997, we exercised this option by payment of the sum of $500,000
to the Knobel Trust. We paid such amount with a portion of the proceeds of the
Metromedia Loan.
 
   
    On February 11, 1997, we entered into an agreement with Mr. Sahagen. In this
agreement, we agreed to pay Mr. Sahagen a fee of $250,000 upon an equity
investment in Metromedia Fiber Network of at least $10 million, in full and
complete payment for all services rendered by Mr. Sahagen in his capacity as
Acting Vice Chairman--Finance of Metromedia Fiber Network and in facilitating
the Metromedia Investment and for any fees or compensation due to Mr. Sahagen
pursuant to any prior agreements with us. Mr. Sahagen agreed to release us from
any claims against us, subject to payments required by the agreement. We agreed
to designate Mr. Sahagen or a suitable designee selected by Mr. Sahagen as a
Director of Metromedia Fiber Network for a term of six months. We also granted
Mr. Sahagen certain "piggyback" registration rights. In connection with the
Metromedia Investment, we paid the $250,000 fee to Mr. Sahagen.
    
 
   
    On December 13, 1996, we issued and sold to Penny Lane Partners, L.P., for
aggregate cash consideration of $2,025,000, (i) 600,000 shares of 10% cumulative
convertible preferred stock (the "Series A Preferred Stock") bearing dividends
at a rate of $.34 per share per annum, (ii) warrants to purchase 456,300 shares
of Class A Common Stock at an exercise price of $1.24 per share and (iii) a
contingent stock subscription warrant to purchase a number of shares of Class A
Common Stock (such number to be determined based on certain future events) at an
exercise price of $0.01 per share. In connection with the Metromedia Investment,
Penny Lane allowed the Series A Preferred Stock and the contingent warrants to
be redeemed at an aggregate redemption price of $2,115,000 (which includes
accrued but unpaid dividends on the Series A Preferred Stock) and the number of
shares underlying the Penny Lane warrants from 456,300 to 912,600. In January
1998, Penny Lane made a cashless exercise of all its warrants and the number of
its shares issuable upon exercise was reduced by the number of shares at the
closing on the day of exercise having a value equal to the aggregate exercise
price. Accordingly, we issued Penny Lane 1,382,048 shares for all its warrants.
    
 
RECENT TRANSACTIONS
 
   
    METROMEDIA INVESTMENT. On February 10, 1997, Metromedia Company agreed to
loan us $2,000,000. Please refer to the section in this Prospectus entitled
"Security Ownership." In an agreement dated March 6, 1997, Metromedia Company
agreed to loan to us up to an additional $6,000,000, subject to certain
conditions (together with the loan on February 10, the "Metromedia Loan"). On
April 30, 1997, we repaid the Metromedia Loan with a portion of the proceeds
from the Metromedia Investment. The Metromedia Loan was funded in two
installments: (i) $1,140,000 on February 10, 1997 and (ii) $860,000 on February
14, 1997. It provided for a revolving loan of up to an additional $6,000,000.
The Metromedia Loan was scheduled to mature on August 31, 1997 and bore interest
at the prime rate announced by The Chase Manhattan Bank. We used the proceeds
from the first installment of the Metromedia Loan to fund an escrow account
which repurchased on our behalf 2,353,880 shares of Class A Common Stock and
warrants to purchase 831,532 shares of Class A Common Stock. We pledged these
repurchased Securities to Metromedia Company as security for the Metromedia
Loan. We used the proceeds from the other installments of the Metromedia Loan
for working capital. On April 30, 1997, we entered into an agreement (the
"Metromedia Agreement"), in which we sold to Metromedia Company, Mr. Subotnick,
Mr. Wadler and Ms. Kessel shares of Series B Convertible Preferred Stock, par
value $.01 per share (the "Series B Preferred Stock") (which constituted 100% of
such series), for $32,500,000. The shares of the Series B Preferred Stock were
exchanged for 16,884,636 shares of Class B Common Stock pursuant to the Series B
Reclassification (as described below). We used the proceeds from this
transaction to redeem the Series A Preferred Stock and contingent warrants
($2,115,000), to repay the Metromedia Loan and accrued interest thereon
($4,058,126), to repay indebtedness to US ONE Communications of New York
($1,370,000), to repay indebtedness to
    
 
                                       63
<PAGE>
   
Sterling Capital LLC ($555,000), and used the balance for working capital. Upon
repayment of the Metromedia Loan, the repurchased shares were released from
escrow and delivered to us.
    
 
   
    MODIFICATION AGREEMENT. On October 28, 1997, we entered into a modification
agreement with Metromedia Company, Mr. Subotnick, Mr. Wadler, Ms. Kessel and Mr.
Garofalo under which the Metromedia Agreement was modified and Metromedia
Company, Mr. Subotnick, Mr. Wadler, Ms. Kessel and Mr. Garofalo agreed to vote
all of their shares of Series B Preferred Stock, common stock and Class A Common
Stock to approve of the adoption of our amended and restated certificate of
incorporation, the reclassification of the common stock into Class A Common
Stock and of the Series B Preferred Stock into Class B Common Stock and the
reverse stock split of shares of the Class A Common Stock and shares of the
Class B Common Stock, as more fully described below.
    
 
   
    TRADEMARK LICENSE AGREEMENT. We are a party to a license agreement with
Metromedia Company, pursuant to which Metromedia Company has granted us a
nonexclusive, nontransferable, nonassignable right and license, without the
right to grant sublicenses, to use the trade name, trademark and corporate name
"Metromedia" in the United States and worldwide, royalty-free for a term of 10
years. The Metromedia license agreement can be terminated by Metromedia Company
upon one month's prior written notice in the event that (i) Metromedia Company
or its affiliates own less than 20% of the common stock; (ii) a "change in
control of Metromedia Fiber Network" occurs; or (iii) any of the stock or all or
substantially all of the assets of any of our subsidiaries are sold or
transferred, in which case, the Metromedia license agreement will terminate with
respect to such subsidiary. A "change in control of Metromedia Fiber Network" is
defined as (i) a transaction in which a person or "group" (within the meaning of
Section 13(d)(3) of the Securities Exchange Act of 1934) not in existence at the
time of the execution of the Metromedia license agreement becomes the beneficial
owner of stock entitling such person or group to exercise 50% or more of the
combined voting power of all classes of stock of Metromedia Fiber Network; (ii)
a change in the composition of board of directors whereby a majority of the
members thereof are not directors serving on the board of directors at the time
of the Metromedia license agreement or any person succeeding such director who
was recommended or elected by such directors; (iii) a reorganization, merger or
consolidation where following consummation thereof, Metromedia Company would
hold less than 20% of the combined voting power of all classes of Metromedia
Fiber Network stock; (iv) a sale or other disposition of all or substantially
all of the assets of Metromedia Fiber Network; or (v) any transaction the result
of which would be that the common stock would not be required to be registered
under the Securities Exchange Act of 1934 and the holders of common stock would
not receive common stock of the survivor to the transaction which is required to
be registered under the Securities Exchange Act of 1934.
    
 
   
    In addition, Metromedia Company has reserved the right to terminate the
Metromedia license agreement in its entirety immediately upon written notice to
us if, in Metromedia Company's sole judgment, our continued use of "Metromedia"
as a trade name would jeopardize or be detrimental to the good will and
reputation of Metromedia Company.
    
 
   
    Pursuant to the Metromedia license agreement, we have agreed to indemnify
Metromedia Company and hold it harmless against any and all losses, claims,
suits, actions, proceedings, investigations, judgments, deficiencies, damages,
settlements, liabilities and reasonable legal expenses (and other expenses
related thereto) arising in connection with the Metromedia license agreement.
    
 
   
    SHARE RECLASSIFICATION AND EXCHANGES. On September 23, 1997, in connection
with our initial public offering, we approved of a reverse stock split pursuant
to which each share of the old common stock, par value $.01 per share, was
converted into .507 shares of the old common stock. On October 28, 1997, we
approved two share exchanges pursuant to which 9,564,940 shares of the old
common stock, par value $.01 per share, were exchanged for the same number of
shares of Class A Common Stock and a total of 8,403.25 shares of the Series B
Convertible Preferred Stock, par value $.01 per share, of Metromedia Fiber
Network held by Metromedia Company, Stuart Subotnick, Arnold Wadler and Silvia
    
 
                                       64
<PAGE>
   
Kessel were exchanged for 4,260,486 shares of our Class B Common Stock (without
giving effect to the stock splits) (the "Series B Reclassification"). Messrs.
Kluge, Subotnick and Wadler and Ms. Kessel are directors of Metromedia Fiber and
Messrs. Kluge and Subotnick are general partners of, and Mr. Wadler and Ms.
Kessel are executive officers of, Metromedia Company. Immediately thereafter,
Mr. Wadler and Ms. Kessel converted an aggregate of 39,327 shares of Class B
Common Stock into an equivalent number of shares of Class A Common Stock. These
exchanges were exempt from registration under the Securities Act, by virtue of
Section 3(a)(9) of such Act.
    
 
   
    MANAGEMENT AGREEMENT. We are a party to the management agreement under which
Metromedia Company provides us with consultation and advisory services relating
to legal matters, insurance, personnel and other corporate policies, cash
management, internal audit and finance, taxes, benefit plans and other services
as we may reasonably request. The management agreement terminated on December
31, 1998, and is automatically renewed for successive one year terms unless
either party terminates upon 60 days prior written notice. The management fee
under the management agreement is $500,000 per year, payable monthly at a rate
of $41,667 per month. We are also obligated to reimburse Metromedia Company all
its out-of-pocket costs and expenses incurred and advances paid by Metromedia
Company in connection with the management agreement. In this agreement, we have
agreed to indemnify Metromedia Company and hold it harmless from and against any
and all damages, liabilities, losses, claims, actions, suits, proceedings, fees,
costs or expenses (including reasonable attorneys' fees and other costs and
expenses incident to any suit, proceeding or investigation of any kind) imposed
on, incurred by or asserted against Metromedia Company in connection with the
management agreement. In 1997, Metromedia Company received no money for its
out-of-pocket costs and expenses or for interest on advances extended by it to
us under the management agreement. For the year ended December 31, 1998, we
incurred $500,000 to Metromedia Company under this agreement.
    
 
   
    STOCK SPLITS. On July 23, 1998, the executive committee of the board of
directors approved a two-for-one stock split of the shares of Class A Common
Stock and Class B Common Stock in the form of a 100% stock dividend. The stock
dividend was issued to stockholders of record as of the close of business on
August 7, 1998. As of September 30, 1998, adjusted for the effect of such stock
split, we had 38,730,226 shares of Class A Common Stock outstanding and
8,442,318 shares of Class B Common Stock outstanding. On December 3, 1998, the
executive committee of the board of directors approved a two-for-one stock split
of the shares of Class A Common Stock and Class B Common Stock in the form of a
100% stock dividend. The stock dividend was issued to stockholders of record as
of the close of business on December 8, 1998. As of January 8, 1999, adjusted
for the effect of the Stock Splits, we had 77,605,110 shares of Class A Common
Stock outstanding and 16,884,636 shares of Class B Common Stock outstanding.
    
 
                                       65
<PAGE>
                               SECURITY OWNERSHIP
 
SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
 
   
    The following table provides you with certain information, as of January 1,
1999, regarding the beneficial ownership of our voting stock after giving effect
to the stock splits by (i) each of our directors and director nominees, (ii)
each person whom we believe beneficially owns more than 5% of our outstanding
voting stock, (iii) each named executive officer and (iv) all our executive
officers and directors as a group. In accordance with the rules promulgated by
the Securities and Exchange Commission, such ownership includes shares currently
owned as well as shares which the named person has the right to acquire
beneficial ownership of within 60 days, including through the exercise of
options, warrants or other rights, or through the conversion of a security.
Accordingly, more than one person may be deemed to be a beneficial owner of the
same securities. Except as otherwise indicated, each stockholder listed below
has sole voting and investment power of the shares beneficially owned by such
person.
    
 
   
<TABLE>
<CAPTION>
                                        CLASS A                  CLASS B
                                     COMMON STOCK            COMMON STOCK(1)
                                 ---------------------    ----------------------
<S>                              <C>             <C>      <C>             <C>      <C>
                                                 PERCENT                  PERCENT
                                   NUMBER         OF        NUMBER          OF         PERCENT OF
                                  OF SHARES      CLASS     OF SHARES      CLASS    TOTAL VOTING POWER
                                 -----------     -----    -----------     ------   ------------------
Stephen A. Garofalo...........    22,747,756(2)  25.7%        --           --               8.9%
Metromedia Company............       --           *        15,731,024      93.2%           61.3%(3)
Putnam Investments, Inc.......    11,309,872(4)  12.8%        --           --               4.4%
Howard M. Finkelstein.........     6,099,000(5)   6.9%        --           --               2.4%
Vincent A. Galluccio..........       715,920(6)   *           --           --                 *
Gerard Benedetto..............       102,000(7)   *           --           --                 *
Nicholas M. Tanzi.............       138,440(8)   *           --           --                 *
Silvia Kessel.................       255,236(9)   *           --           --                 *
John W. Kluge.................     1,014,000(10)  1.1%     15,731,024(11)  93.2%           61.7%
David Rockefeller.............     1,414,552(12)  1.6%        --           --                 *
Stuart Subotnick..............     1,014,000(10)  1.1%     16,884,636(11) 100.0%           66.2%
Arnold L. Wadler..............       307,672(9)   *           --           --                 *
Leonard White.................        23,000(13)  *           --           --                 *
All Directors and Executive
  Officers as a Group.........    33,831,576(14) 38.2%     16,884,636     100.0%           78.6%
</TABLE>
    
 
- ------------------------
 
*   less than 1.0%
 
(1) The shares of Class B Common Stock are convertible into shares of Class A
    Common Stock at the rate of one share of Class A Common Stock for each share
    of Class B Common Stock and the holders of shares of Class B Common Stock
    are entitled to 10 votes per share.
 
(2) Includes presently exercisable options to purchase 1,521,000 shares of Class
    A Common Stock at an exercise price of $.49 per share. Mr. Garofalo's
    address is One North Lexington Avenue, White Plains, New York 10601.
 
   
(3) Metromedia Company's address is One Meadowlands Plaza, East Rutherford, NJ
    07073.
    
 
   
(4) Based solely upon the Schedule 13-G, dated September 18, 1998, filed by
    Putnam Investments, Inc. The Putnam Investments, Inc. address is One Post
    Office Square, Boston, Massachusetts, 02109.
    
 
   
(5) Includes presently exercisable options to purchase 6,084,000 shares of Class
    A Common Stock at an exercise price of $.49 per share and 15,000 shares of
    Class A Common Stock owned by
    
 
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<PAGE>
   
    members of Mr. Finkelstein's family. Mr. Finkelstein's address is One North
    Lexington Avenue, White Plains, New York 10601.
    
 
   
(6) Represents presently exercisable options to purchase 640,920 and 75,000
    shares of Class A Common Stock at an exercise price of $.49 and $4.00 per
    share, respectively.
    
 
   
(7) Includes presently exercisable options to purchase 100,000 shares of Class A
    Common Stock at an exercise price of $3.88 per share.
    
 
   
(8) Includes presently exercisable options to purchase 60,840 and 75,000 shares
    of Class A Common Stock at an exercise price of $1.91 and $4.00 per share,
    respectively. Also, includes 2,600 shares of Class A Common Stock owned by
    members of Mr. Tanzi's family to which Mr. Tanzi has been granted a proxy to
    vote. Mr. Tanzi's address is One North Lexington Avenue, White Plains, New
    York 10601.
    
 
   
(9) Includes 202,800 presently exercisable options to acquire shares of Class A
    Common Stock at an exercise price of $.49 per share held by each of Ms.
    Kessel and Mr. Wadler. Does not include shares owned by Metromedia Company.
    Ms. Kessel and Mr. Wadler are employed by Metromedia Company and disclaim
    beneficial ownership of the shares owned by Metromedia Company.
    
 
   
(10) Consists of 1,014,000 presently exercisable options to acquire shares of
    Class A Common Stock at an exercise price of $.49 per share held by each of
    Mr. Kluge and Mr. Subotnick. Mr. Kluge's address is 215 East 67th Street,
    New York, NY 10021 and Mr. Subotnick's address is 215 East 67th Street, New
    York, NY 10021.
    
 
   
(11) Includes 15,731,024 shares owned by Metromedia Company. Messrs. Kluge and
    Subotnick, Directors of Metromedia Fiber Network, are general partners of
    Metromedia Company.
    
 
   
(12) Represents 1,394,552 shares owned by DR & Descendants Partnership, of which
    Mr. Rockefeller is a partner and for which he exercises voting and
    investment power and presently exercisable options to purchase 20,000 shares
    of Class A Common Stock at an exercise price of $4.00 per share. Mr.
    Rockefeller disclaims actual beneficial ownership of shares owned by DR &
    Descendants Partnership except as to shares attributable to his
    proportionate interest in the partnership.
    
 
   
(13) Includes 20,000 presently exercisable options to acquire shares of Class A
    Common Stock at an exercise price of $4.00 per share.
    
 
   
(14) Includes presently exercisable options to acquire 10,679,520, 60,840,
    100,000 and 190,000 shares of Class A Common Stock at an exercise price of
    $.49, $1.91, $3.88 and $4.00 per share, respectively.
    
 
                                       67
<PAGE>
                               THE EXCHANGE OFFER
 
PURPOSE OF THE EXCHANGE OFFER
 
   
    Our registration rights agreement, requires us to file not later than
February 23, 1999 (90 days following the date of original issuance of the
initial notes) the registration statement of which this Prospectus is a part for
a registered exchange offer with respect to an issue of new notes in exchange
for our initial notes. The exchange notes will be substantially identical in all
material respects to the initial notes except that the exchange notes will be
registered under the Securities Act, will not bear legends restricting their
transfer and will not be entitled to registration rights under our registration
rights agreement. This summary of certain provisions of the registration rights
agreement does not contain all the information that you should consider and we
refer you to the provisions of the registration rights agreement, which has been
filed as an exhibit to the registration statement of which this Prospectus is a
part and a copy of which is available as indicated under the heading "Available
Information."
    
 
   
    We are required to:
    
 
   
    - use our reasonable best efforts to cause the registration statement to be
      declared effective no later than May 24, 1999 (180 days after the date of
      issuance of the initial notes),
    
 
   
    - keep the exchange offer effective for not less than 20 business days (or
      longer if required by applicable law) after the date that notice of the
      exchange offer is mailed to holders of the initial notes, and
    
 
   
    - use our reasonable best efforts to consummate the exchange offer no later
      than June 23, 1999 (210 days after the date of issuance of the initial
      notes).
    
 
   
    The exchange offer being made here, if commenced and consummated within the
time periods described in this paragraph, will satisfy those requirements under
the registration rights agreement.
    
 
   
    This Prospectus, together with the letter of transmittal, is being sent to
all record holders of initial notes as of       , 1999.
    
 
   
    Based on interpretations by the staff of the Securities and Exchange
Commission, as provided in no-action letters issued to third parties, we believe
that the exchange notes issued pursuant to the exchange offer may be offered for
resale, resold or otherwise transferred by each holder of exchange notes (other
than a broker-dealer who acquires the initial notes directly from Metromedia
Fiber Network for resale pursuant to Rule 144A under the Securities Act or any
other available exemption under the Securities Act, and other than any holder
that directly or indirectly through one or more intermediaries, controls or is
controlled by, or is under common control with, Metromedia Fiber Network)
without compliance with the registration and prospectus delivery provisions of
the Securities Act, provided that such holder:
    
 
   
    - is acquiring the exchange notes in the ordinary course of its business,
    
 
   
    - is not participating in, and does not intend to participate in, a
      distribution of such exchange notes within the meaning of the Securities
      Act and has no arrangement or understanding with any person to participate
      in a distribution of the exchange notes within the meaning of the
      Securities Act, and
    
 
   
    - is not a person that directly, or indirectly through one or more
      intermediaries, controls or is controlled by, or is under common control
      with, Metromedia Fiber Network.
    
 
   
    By tendering the initial notes in exchange for exchange notes, each holder,
other than a broker-dealer, will be required to make representations to that
effect. If a holder of initial notes is participating in or intends to
participate in, a distribution of the exchange notes, or has any
    
 
                                       68
<PAGE>
   
arrangement or understanding with any person to participate in a distribution of
the exchange notes to be acquired pursuant to the exchange offer, such holder
may be deemed to have received restricted securities and may not rely on the
applicable interpretations of the staff of the Securities and Exchange
Commission. Any such holder will have to comply with the registration and
prospectus delivery requirements of the Securities Act in connection with any
secondary resale transaction.
    
 
   
    Each broker-dealer that receives exchange notes for its own account in
exchange for initial notes may be deemed to be an "underwriter" within the
meaning of the Securities Act and must acknowledge that it will deliver a
prospectus meeting the requirements of the Securities Act in connection with any
resale of such exchange notes. The letter of transmittal states that by so
acknowledging and by delivering a prospectus, a broker-dealer will not be deemed
to admit that it is an "underwriter" within the meaning of the Securities Act.
This Prospectus, as it may be amended or supplemented from time to time, may be
used by a broker-dealer in connection with offers to resell, resales and other
transfers of exchange notes received in exchange for initial notes which were
acquired by such broker-dealer as a result of market making or other trading
activities. We have agreed that we will make this Prospectus available to any
broker-dealer for a period of time not to exceed 180 days after the consummation
of the exchange offer for use in connection with any such offer to resell,
resale or other transfer. Please refer to the section in this Prospectus
entitled "Plan of Distribution."
    
 
SHELF REGISTRATION STATEMENT
 
    In the event that:
 
   
    (i) because of any change in law or applicable interpretations thereof by
the staff of the Securities and Exchange Commission, we are not permitted to
effect the exchange offer, or
    
 
   
    (ii) for any other reason, the exchange offer is not consummated within 180
days from the date of issuance of the initial notes, or
    
 
   
    (iii) any holder of initial notes notifies us within 20 days following the
consummation of the exchange offer that (x) such holder was prohibited by law of
policy of the Securities and Exchange Commission from participating in the
exchange offer, or (y) such holder may not resell the exchange notes acquired by
it in the exchange offer to the public without delivering a prospectus and this
Prospectus is not appropriate or available for such resale, or (z) such holder
is a broker-dealer and holds notes acquired directly from us or any of our
affiliates (within the meaning of the Securities Act), then in the case of
clauses (i) through (iii) of this sentence, we will be obligated, at our sole
expense, to:
    
 
   
    - use our reasonable best efforts, as promptly as practicable and in no
      event more than 30 days following such request, to file with the
      Securities and Exchange Commission a shelf registration statement covering
      resales of the initial notes,
    
 
   
    - use our reasonable best efforts to cause the shelf registration statement
      to be declared effective under the Securities Act within 120 days after
      the date we are required to file a shelf registration statement, and
    
 
   
    - use our reasonable best efforts to keep the shelf registration statement
      continuously effective, supplemented and amended as required by the
      Securities Act, in order to permit the prospectus which is a part of such
      shelf registration statement to be usable by holders for a period of two
      years after the shelf registration statement is declared effective or such
      shorter period of time that will terminate when all of the applicable
      initial notes have been sold thereunder.
    
 
   
    We will, in the event that a shelf registration statement is filed, provide
to each holder of the initial notes being registered copies of the prospectus
that is a part of the shelf registration statement, notify each such holder when
the shelf registration statement has become effective and take certain
    
 
                                       69
<PAGE>
   
other actions as are required to permit unrestricted resales of the initial
notes being registered. A holder that sells initial notes pursuant to the shelf
registration statement will be required to be named as a selling security holder
in the related prospectus and to deliver a prospectus to purchasers, will be
subject to certain of the civil liability provisions under the Securities Act in
connection with such sales and will be bound by the provisions of the
registration rights agreement that are applicable to such a holder (including
certain indemnification rights and obligations).
    
 
LIQUIDATED DAMAGES
 
    In the event that:
 
   
    (i) we do not file the registration statement or the shelf registration
statement, as the case may be, with the Securities and Exchange Commission on or
before the dates specified above for such filings,
    
 
   
    (ii) the registration statement or the shelf registration statement, as the
case may be, is not declared effective on or before the dates specified above
for such effectiveness,
    
 
   
    (iii) the exchange offer is not consummated on or before June 23, 1999 (210
days after the date of issuance of the initial notes), or
    
 
   
    (iv) the shelf registration statement is filed and declared effective but
thereafter ceases to be effective or usable in connection with its intended
purpose (each such event referred to in clauses (i) through (iv), a
"registration default"),
    
 
   
then we will be obligated to pay to each holder of "transfer restricted
securities" (as defined in our registration rights agreement) liquidated
damages. Liquidated damages will accrue and be payable semi-annually on the
initial notes and the exchange notes (in addition to the stated interest on the
initial notes and the exchange notes) in an amount equal to 0.50% per year
during the first 90-day period, which will increase by 0.25% per year for each
subsequent 90-day period. In no event will such rate exceed 1.50% per year in
the aggregate, regardless of the number of registration defaults. Liquidated
damages will accrue from the date a registration default occurs until the date
on which:
    
 
   
    - the registration statement is filed,
    
 
   
    - the registration statement or shelf registration statement is declared
      effective and the exchange offer is consummated,
    
 
   
    - the shelf registration statement is declared effective, or
    
 
   
    - the shelf registration statement again becomes effective or made usable,
      as the case may be.
    
 
   
    Following the cure of all registration defaults, the accrual of liquidated
damages will cease.
    
 
   
    Upon consummation of the exchange offer, subject to certain exceptions,
holders of initial notes who do not exchange their initial notes for exchange
notes in the exchange offer will no longer be entitled to registration rights
and will not be able to offer or sell their initial notes, unless such initial
notes are subsequently registered under the Securities Act (which, subject to
certain limited exceptions, we will have no obligation to do), or pursuant to an
exemption from, or in a transaction not subject to, the Securities Act and
applicable state securities laws. Please refer to the section in this Prospectus
entitled "Risk Factors--Your Failure to Participate in The Exchange Offer Will
Have Adverse Consequences."
    
 
TERMS OF THE EXCHANGE OFFER
 
    EXPIRATION DATE; EXTENSIONS; AMENDMENTS; TERMINATION
 
   
    The exchange offer will expire at 5:00 p.m., New York City time, on
           , 1999, unless we extend it in our reasonable discretion (such date
as it may be extended is referred to in this Prospectus
    
 
                                       70
<PAGE>
   
as the "expiration date"). The expiration date will be at least 20 business days
after the commencement of the exchange offer in accordance with Rule 14e-1(a)
under the Securities Exchange Act of 1934 and the registration rights agreement.
    
 
   
    To extend the expiration date, we will need to notify the exchange agent of
any extension by oral (promptly confirmed in writing) or written notice and to
notify the holders of the initial notes by mailing an announcement or by means
of a press release or other public announcement communicated, unless otherwise
required by applicable law or regulation, before 9:00 A.M., New York City time,
on the next business day after the previously scheduled expiration date.
    
 
    We expressly reserve the right:
 
   
    - to delay acceptance of any initial notes, to extend the exchange offer or
      to terminate the exchange offer and not permit acceptance of initial notes
      not previously accepted if any of the conditions set forth below under
      "--Conditions" have occurred and have not been waived by us (if permitted
      to be waived), by giving oral or written notice of such delay, extension
      or termination to the exchange agent, or
    
 
   
    - to amend the terms of the exchange offer in any manner.
    
 
   
    If we amend the exchange offer in a manner determined by us to constitute a
material change, we will promptly disclose such amendment in a manner reasonably
calculated to inform the holders of the initial notes of such amendment
including providing public announcement, or giving oral or written notice to the
holders of the initial notes. A material change in the terms of the exchange
offer could include, among other things, a change in the timing of the exchange
offer, a change in the exchange agent, and other similar changes in the terms of
the exchange offer. If any material change is made to terms of the exchange
offer, we will disclose such change by means of a post-effective amendment to
the registration statement of which this Prospectus is a part and will
distribute an amended or supplemented Prospectus to each registered holder of
initial notes. In addition, we will also extend the exchange offer for an
additional five to ten business days as required by the Securities Exchange Act
of 1934, depending on the significance of the amendment, if the exchange offer
would otherwise expire during such period. Any such delay in acceptance,
extension, termination or amendment will be followed as promptly as practicable
by oral (promptly confirmed in writing) or written notice thereof to the
exchange agent.
    
 
    PROCEDURES FOR TENDERING
 
   
    To tender your initial notes in the exchange offer, you must complete, sign
and date the letter of transmittal, or a facsimile thereof, have the signatures
thereon guaranteed if required by the letter of transmittal, and mail or
otherwise deliver the letter of transmittal or the facsimile, or an agent's
message (as defined below), together with the certificates representing the
initial notes being tendered and any other required documents, to the exchange
agent on or before 5:00 p.m., New York City time, on the expiration date.
Alternatively, you may either:
    
 
   
    - send a timely confirmation of a book-entry transfer (a "book-entry
      confirmation") of such initial notes, if such procedure is available, into
      the exchange agent's account at The Depository Trust Company or DTC
      pursuant to the procedure for book-entry transfer described below, on or
      before 5:00 p.m. on the expiration date, or
    
 
    - comply with the guaranteed delivery procedures described below.
 
   
    The term "agent's message" means a message, transmitted by DTC to, and
received by, the exchange agent and forming a part of a book-entry confirmation,
which states that DTC has received an express acknowledgment from the
participant in DTC tendering initial notes which are the subject
    
 
                                       71
<PAGE>
   
of such book-entry confirmation that such participant has received and agrees to
be bound by the terms of the letter of transmittal, and that we may enforce such
agreement against such participant.
    
 
   
    THE METHOD OF DELIVERY OF THE INITIAL NOTES, THE LETTER OF TRANSMITTAL AND
ALL OTHER REQUIRED DOCUMENTS IS AT YOUR ELECTION AND RISK. INSTEAD OF DELIVERY
BY MAIL, WE RECOMMEND THAT YOU USE AN OVERNIGHT OR HAND-DELIVERY SERVICE. IF YOU
CHOOSE THE MAIL, WE RECOMMEND THAT YOU USE REGISTERED MAIL, PROPERLY INSURED,
WITH RETURN RECEIPT REQUESTED. IN ALL CASES, YOU SHOULD ALLOW SUFFICIENT TIME TO
ASSURE TIMELY DELIVERY. YOU SHOULD NOT SEND ANY LETTERS OF TRANSMITTAL OR
INITIAL NOTES TO US. You must deliver all documents to the exchange agent at its
address provided below. You may also request your respective brokers, dealers,
commercial banks, trust companies or nominees to tender your initial notes on
your behalf.
    
 
   
    Your tender of initial notes will constitute an agreement between you and us
in accordance with the terms and subject to the conditions provided in this
Prospectus and in the letter of transmittal.
    
 
   
    Only a holder of initial notes may tender such initial notes in the exchange
offer. The term "holder" with respect to the exchange offer means any person in
whose name initial notes are registered on our books or any other person who has
obtained a properly completed bond power from the registered holder.
    
 
   
    If you are the beneficial owner of initial notes that are registered in the
name of a broker, dealer, commercial bank, trust company or other nominee and
you wish to tender your initial notes, you should contact such registered holder
promptly and instruct such registered holder to tender on your behalf. If you
wish to tender on your own behalf, you must, before completing and executing the
letter of transmittal and delivering your initial notes, either make appropriate
arrangements to register ownership of the initial notes in your name or obtain a
properly completed bond power from the registered holder. The transfer of
registered ownership may take considerable time.
    
 
   
    Signatures on a letter of transmittal or a notice of withdrawal, as the case
may be, must be guaranteed by a member firm of a registered national securities
exchange or of the National Association of Securities Dealers, Inc., a
commercial bank or trust company having an office or correspondent in the United
States or an "eligible guarantor" institution within the meaning of Rule 17Ad-15
under the Securities Exchange Act of 1934 (each, an "eligible institution"),
unless the initial notes are tendered:
    
 
   
    - by a registered holder (or by a participant in DTC whose name appears on a
      security position listing as the owner) who has not completed the box
      entitled "Special Issuance Instructions" or "Special Delivery
      Instructions" on the letter of transmittal if the exchange notes are being
      issued directly to such registered holder (or deposited into the
      participant's account at DTC), or
    
 
   
    - for the account of an eligible institution.
    
 
   
    If the letter of transmittal is signed by the recordholder(s) of the initial
notes tendered, the signature must correspond with the name(s) written on the
face of the initial notes without alteration, enlargement or any change
whatsoever. If the letter of transmittal is signed by a participant in DTC, the
signature must correspond with the name as it appears on the security position
listing as the holder of the initial notes.
    
 
   
    If the letter of transmittal is signed by a person other than the registered
holder of any initial notes listed, such initial notes must be endorsed or
accompanied by bond powers and a proxy that authorize such person to tender the
initial notes on behalf of the registered holder in satisfactory form to us as
determined in our sole discretion, in each case as the name of the registered
holder or holders appears on the initial notes.
    
 
   
    If the letter of transmittal or any initial notes or bond powers are signed
by trustees, executors, administrators, guardians, attorneys-in-fact, officers
of corporations or others acting in a fiduciary or
    
 
                                       72
<PAGE>
representative capacity, such persons should so indicate when signing. Unless
waived by us, evidence satisfactory to us of their authority to so act must also
be submitted with the Letter of Transmittal.
 
   
    A tender will be deemed to have been received as of the date when the
tendering holder's duly signed letter of transmittal accompanied by the initial
notes tendered (or a timely confirmation received of a book-entry transfer of
initial notes into the exchange agent's account at DTC with an agent's message)
or a notice of guaranteed delivery from an eligible institution is received by
the exchange agent. Issuances of exchange notes in exchange for initial notes
tendered pursuant to a notice of guaranteed delivery by an eligible institution
will be made only against delivery of the letter of transmittal (and any other
required documents) and the tendered initial notes (or a timely confirmation
received of a book-entry transfer of initial notes into the exchange agent's
account at DTC with an agent's message) with the exchange agent.
    
 
   
    All questions as to the validity, form, eligibility (including time of
receipt), acceptance and withdrawal of the tendered initial notes will be
determined by us in our sole discretion. Our determination will be final and
binding. We reserve the absolute right to reject any and all initial notes not
properly tendered or any initial notes which, if accepted, would, in our opinion
or our counsel's opinion, be unlawful. We also reserve the absolute right to
waive any conditions of the exchange offer or irregularities or defects in
tender as to particular initial notes. Our interpretation of the terms and
conditions of the exchange offer (including the instructions in the letter of
transmittal) will be final and binding on all parties. Unless waived, any
defects or irregularities in connection with tenders of initial notes must be
cured within such time as we shall determine. We, the exchange agent or any
other person will be under no duty to give notification of defects or
irregularities with respect to tenders of initial notes. None of us or the
exchange agent will incur any liability for failure to give such notification.
Tenders of initial notes will not be deemed to have been made until such
irregularities have been cured or waived. Any initial notes received by the
exchange agent that are not properly tendered and as to which the defects or
irregularities have not been cured or waived will be returned without cost by
the exchange agent to the tendering holders of such initial notes, unless
otherwise provided in the letter of transmittal, as promptly as practicable
following the expiration date.
    
 
   
    In addition, we reserve the right in our sole discretion, subject to the
provisions of the indenture for the notes, to:
    
 
   
    - purchase or make offers for any initial notes that remain outstanding
      subsequent to the expiration date, or, as set forth under "--Expiration
      Date; Extensions; Amendments; Termination", to terminate the exchange
      offer in accordance with the terms of our registration rights agreement,
      and
    
 
   
    - to the extent permitted by applicable law, purchase initial notes in the
      open market, in privately negotiated transactions or otherwise. The terms
      of any such purchases or offers could differ from the terms of the
      exchange offer.
    
 
    ACCEPTANCE OF INITIAL NOTES FOR EXCHANGE; DELIVERY OF EXCHANGE NOTES
 
   
    Upon satisfaction or waiver of all of the conditions to the exchange offer,
we will accept all initial notes properly tendered, promptly after the
expiration date, and will issue the exchange notes promptly after the expiration
date and acceptance of the initial notes. Please refer to the section of this
Prospectus entitled "--Conditions" below. For purposes of the exchange offer,
initial notes will be deemed to have been accepted as validly tendered for
exchange when, as and if we had given oral or written notice to the exchange
agent.
    
 
   
    In all cases, issuance of exchange notes for initial notes that are accepted
for exchange pursuant to the exchange offer will be made only after timely
receipt by the exchange agent of certificates for such initial notes or a timely
book-entry confirmation of such initial notes into the exchange agent's account
    
 
                                       73
<PAGE>
   
at the book-entry transfer facility, a properly completed and duly executed
letter of transmittal or an agent's message and all other required documents, in
each case, in form satisfactory to us and the exchange agent. If any tendered
initial notes are not accepted for any reason set forth in the terms and
conditions of the exchange offer or if initial notes are submitted for a greater
principal amount than the holder desires to exchange, such unaccepted or
non-exchanged initial notes will be returned without expense to the tendering
holder thereof (or, in the case of initial notes tendered by book-entry transfer
procedures described below, such non-exchanged initial notes will be credited to
an account maintained with such Book-Entry Transfer Facility) as promptly as
practicable after withdrawal, rejection of tender, the expiration date or
earlier termination of the exchange offer.
    
 
    BOOK-ENTRY TRANSFER
 
   
    The exchange agent will make a request to establish an account with respect
to the initial notes at DTC for purposes of the exchange offer within two
business days after the date of this Prospectus. Any financial institution that
is a participant in DTC's systems may make book-entry delivery of initial notes
by causing DTC to transfer such initial notes into the exchange agent's account
at DTC in accordance with DTC's procedures for transfer.
    
 
   
    However, although delivery of initial notes may be effected through
book-entry transfer into the exchange agent's account at DTC, an agent's message
or the letter of transmittal or facsimile thereof with any required signature
guarantees and any other required documents must, in any case, be transmitted to
and received by the exchange agent at the address set forth below under
"--Exchange Agent" on or prior to the expiration date or the guaranteed delivery
procedures described below must be complied with. DELIVERY OF DOCUMENTS TO DTC
DOES NOT CONSTITUTE DELIVERY TO THE EXCHANGE AGENT. All references in the
Prospectus to deposit of initial notes will be deemed to include DTC's
book-entry delivery method.
    
 
    GUARANTEED DELIVERY PROCEDURE
 
   
    If you are a registered holder of initial notes and desire to tender such
initial notes, and the initial notes are not immediately available, or time will
not permit your initial notes or other required documents to reach the exchange
agent before the expiration date, or the procedures for book-entry transfer
cannot be completed on a timely basis and an agent's message delivered, you may
still tender in the exchange offer if:
    
 
   
    - you tender through an eligible institution,
    
 
   
    - prior to the expiration date, the exchange agent receives from such
      eligible institution a properly completed and duly executed letter of
      transmittal (or facsimile thereof) and notice of guaranteed delivery,
      substantially in the form provided by us (by facsimile transmission, mail
      or hand delivery), setting forth your name and address as holder of the
      initial notes and the amount of initial notes tendered, stating that the
      tender is being made thereby and guaranteeing that within five business
      days after the expiration date the certificates for all tendered initial
      notes, in proper form for transfer, or a book-entry confirmation with an
      agent's message, as the case may be, and any other documents required by
      the letter of transmittal will be deposited by the eligible institution
      with the exchange agent, and
    
 
   
    - the certificates for all tendered initial notes, in proper form for
      transfer, or a book-entry confirmation as the case may be, and all other
      documents required by the letter of transmittal are received by the
      exchange agent within five business days after the expiration date.
    
 
                                       74
<PAGE>
    WITHDRAWAL OF TENDERS
 
   
    Except as otherwise provided in this Prospectus, you may withdraw tenders of
initial notes at any time before 5:00 p.m., New York City time, on the
expiration date.
    
 
   
    For a withdrawal to be effective, you must send a written or facsimile
transmission notice of withdrawal to the exchange agent before 5:00 p.m., New
York City time, on the expiration date at the address provided below under
"--Exchange Agent" and before acceptance for exchange thereof by us. Any notice
of withdrawal must:
    
 
   
    - specify the name of the person having tendered the initial notes to be
      withdrawn,
    
 
   
    - identify the initial notes to be withdrawn (including, if applicable, the
      registration number or numbers and total principal amount of such initial
      notes),
    
 
   
    - be signed by the person having tendered the initial notes to be withdrawn
      in the same manner as the original signature on the letter of transmittal
      by which such initial notes were tendered (including any required
      signature guarantees) or be accompanied by documents of transfer
      sufficient to permit the Trustee with respect to the initial notes to
      register the transfer of such initial notes into the name of the person
      having made the original tender and withdrawing the tender,
    
 
   
    - specify the name in which any such initial notes are to be registered, if
      different from that of the person having tendered the initial notes to be
      withdrawn, and
    
 
   
    - if applicable because the initial notes have been tendered pursuant to the
      book-entry procedures, specify the name and number of the participant's
      account at DTC to be credited, if different than that of the person having
      tendered the initial notes to be withdrawn.
    
 
   
    We will determine all questions as to the validity, form and eligibility
(including time of receipt) of such notices and our determination will be final
and binding on all parties. Any initial notes so withdrawn will be deemed not to
have been validly tendered for exchange for purposes of the exchange offer. Any
initial notes which have been tendered for exchange which are not exchanged for
any reason will be returned to the holder thereof without cost to such holder
(or, in the case of initial notes tendered by book-entry transfer into the
exchange agent's account at DTC pursuant to the book-entry transfer procedures
described above, such initial notes will be credited to an account maintained
with DTC for the initial notes) as promptly as practicable after withdrawal,
rejection of tender, expiration date or earlier termination of the exchange
offer. Properly withdrawn initial notes may be retendered by following one of
the procedures described under "--Procedures for Tendering" and "--Book-Entry
Transfer" above at any time on or before the expiration date.
    
 
    CONDITIONS
 
   
    Notwithstanding any other term of the exchange offer, we will not be
required to accept initial notes for exchange, or issue exchange notes in
exchange for any initial notes, and we may terminate or amend the exchange offer
as provided in this Prospectus before the acceptance of such initial notes, if:
    
 
   
    - an action or proceeding has been instituted or threatened in any court or
      before any governmental agency or body that in our judgment would
      reasonably be expected to prohibit, prevent or otherwise impair our
      ability to proceed with the exchange offer;
    
 
   
    - a change in the current interpretation of the staff of the Securities and
      Exchange Commission has occurred which current interpretation permits the
      exchange notes issued pursuant to the exchange offer in exchange for the
      initial notes to be offered for resale, resold or otherwise transferred by
      holders thereof (other than in certain circumstances);
    
 
                                       75
<PAGE>
   
    - a law, statute, rule or regulation has been adopted or enacted which, in
      our judgment, would reasonably be expected to impair our ability to
      proceed with the exchange offer;
    
 
   
    - a stop order has been issued by the Securities and Exchange Commission or
      any state securities authority suspending the effectiveness of the
      registration statement of which this Prospectus is a part or the
      qualification of the indenture for the notes under the Trust Indenture Act
      of 1939 or proceedings shall have been initiated or, to our knowledge,
      threatened for that purpose;
    
 
   
    - a governmental approval has not been obtained, which approval we deem in
      our sole discretion, necessary for the consummation of the exchange offer;
      or
    
 
   
    - a change, or a development involving a prospective change, in our business
      or financial affairs has occurred which, in our sole judgment, might
      materially impair our ability to proceed with the exchange offer.
    
 
    These conditions are for our sole benefit and may be asserted by us
regardless of the circumstances giving rise to any such condition or may be
waived by us, in whole or in part, at any time and from time to time, if we
determine in our reasonable discretion that any of the foregoing events or
conditions has occurred or exists or has not been satisfied, subject to
applicable law. Our failure at any time to exercise any of the foregoing rights
will not be deemed a waiver of any such right and each such right will be deemed
an ongoing right which we may assert at any time and from time to time.
 
   
    If we determine that we may terminate the exchange offer, as provided above,
we may:
    
 
   
    - refuse to accept any initial notes and return any initial notes that have
      been tendered to the holders thereof,
    
 
   
    - extend the exchange offer and retain all initial notes tendered prior to
      the expiration date, subject to the rights of such holders of tendered
      initial notes to withdraw their tendered initial notes, or
    
 
   
    - waive such termination event with respect to the exchange offer and accept
      all properly tendered initial notes that have not been withdrawn or
      otherwise amend the terms of the exchange offer in any respect as provided
      under the section in this Prospectus entitled "--Expiration Date;
      Extensions; Amendments; Termination."
    
 
   
    The exchange offer is not conditioned upon any minimum principal amount of
initial notes being tendered for exchange.
    
 
   
    We have no obligation to, and will not knowingly, permit acceptance of
tenders of initial notes from our affiliates (within the meaning of Rule 405
under the Securities Act) or from any other holder or holders who are not
eligible to participate in the Exchange Offer under applicable law or
interpretations thereof by the Securities and Exchange Commission, or if the
exchange notes to be received by such holder or holders of initial notes in the
exchange offer, upon receipt, will not be tradable by such holder without
restriction under the Securities Act and the Securities Exchange Act of 1934 and
without material restrictions under the "blue sky" or securities laws of
substantially all of the states of the United States.
    
 
    ACCOUNTING TREATMENT
 
   
    We will record the exchange notes at the same carrying value as the initial
notes, as reflected in our accounting records on the date of the exchange.
Accordingly, we will not recognize any gain or loss for accounting purposes. We
will amortize the costs of the exchange offer and the unamortized expenses
related to the issuance of the exchange notes over the term of the exchange
notes.
    
 
                                       76
<PAGE>
    EXCHANGE AGENT
 
   
    We have appointed IBJ Whitehall Bank & Trust Company as exchange agent for
the exchane offer. You should direct all questions and requests for assistance
or additional copies of this Prospectus or the letter of transmittal to the
exchange agent as follows:
    
 
                       By Mail:
                       IBJ Whitehall Bank & Trust Company
                       P.O. Box 84
                       Bowling Green Station
                       New York, NY 10274-0084
                       ATTN: Reorganization Operations Department
 
                       By Hand/Overnight Delivery:
                       IBJ Whitehall Bank & Trust Company
                       One State Street
                       New York, NY 10004
                       ATTN: Securities Processing Window, Subcellar One, (SC-1)
 
                       Facsimile Transmission: (212) 858-2611
                       Confirm by Telephone: (212) 858-2103
                       Via Telex No.: 177754
 
    FEES AND EXPENSES
 
   
    We will bear the expenses of soliciting tenders pursuant to the exchange
offer. The principal solicitation for tenders pursuant to the exchange offer is
being made by mail; however, our offices and regular employees may make
additional solicitations by telegraph, telephone, telecopy or in person.
    
 
   
    We will not make any payments to brokers, dealers or other persons
soliciting acceptances of the exchange offer. However, we will pay the exchange
agent reasonable and customary fees for its services and will reimburse the
exchange agent for its reasonable out-of-pocket expenses in connection with the
exchange offer. We may also pay brokerage houses and other custodians, nominees
and fiduciaries the reasonable out-of-pocket expenses incurred by them in
forwarding copies of the Prospectus, letters of transmittal and related
documents to the beneficial owners of the initial notes, and in handling or
forwarding tenders for exchange.
    
 
   
    We will pay the expenses incurred in connection with the exchange offer,
including fees and expenses of the exchange agent and Trustee and accounting,
legal, printing and related fees and expenses.
    
 
   
    We will pay all transfer taxes, if any, applicable to the exchange of
initial notes pursuant to the exchange offer. However, tendering holders will
pay the amount of any such transfer taxes (whether imposed on the registered
holder or any other persons) if:
    
 
   
    - certificates representing exchange notes or initial notes for principal
      amounts not tendered or accepted for exchange are to be delivered to, or
      are to be registered or issued in the name of, any person other than the
      registered holder of the initial notes tendered, or
    
 
   
    - tendered initial notes are registered in the name of any person other than
      the person signing the letter of transmittal, or
    
 
   
    - a transfer tax is imposed for any reason other than the exchange of
      initial notes pursuant to the exchange offer.
    
 
                                       77
<PAGE>
   
    If satisfactory evidence of payment of such taxes or exemption therefrom is
not submitted with the letter of transmittal, the amount of such transfer taxes
will be billed directly to such tendering holder.
    
 
   
YOUR FAILURE TO PARTICIPATE IN THE EXCHANGE OFFER WILL HAVE ADVERSE CONSEQUENCES
    
 
   
    If you do not exchange your initial notes for exchange notes pursuant to the
exchange offer, you will not be able to resell, offer to resell or otherwise
transfer the initial notes unless they are registered under the Securities Act
or unless you resell them, offer to resell or otherwise transfer them under an
exemption from the registration requirements of, or in a transaction not subject
to, the Securities Act. In addition, you will no longer be able to obligate us
to register the initial notes under the Securities Act except in the limited
circumstances provided under our registration rights agreement. The restrictions
on transfer of your initial notes arise because we issued the initial notes
pursuant to exemptions from, or in transactions not subject to, the registration
requirements of the Securities Act and applicable state securities laws. In
addition, if you want to exchange your initial notes in the exchange offer for
the purpose of participating in a distribution of the exchange notes, you may be
deemed to have received restricted securities, and, if so, will be required to
comply with the registration and prospectus delivery requirements of the
Securities Act in connection with any resale transaction. To the extent the
initial notes are tendered and accepted in the exchange offer, the trading
market, if any, for the initial notes would be adversely affected. Please refer
to the section in this Prospectus entitled "Risk Factors."
    
 
                                       78
<PAGE>
                       DESCRIPTION OF THE EXCHANGE NOTES
 
GENERAL
 
   
    The form and terms of the exchange notes are the same as the form and terms
of the initial notes, except that the exchange notes have been registered under
the Securities Act, will not bear legends restricting the transfer thereof and
will not be entitled to registration rights under our registration rights
agreement. We issued the initial notes and will issue the exchange notes under
the indenture, dated as of November 25, 1998, between us and IBJ Whitehall Bank
& Trust Company, as trustee. The terms of the exchange notes will include those
stated in the indenture and the security agreement, dated as of November 25,
1998, among us, the trustee and IBJ Whitehall Bank & Trust Company as security
intermediary and those made part of the indenture by reference to the Trust
Indenture Act. The exchange notes will be subject to all such terms, and we
refer you to the indenture, the security agreement and the Trust Indenture Act
for a statement of such terms. Except as otherwise indicated, the following
description relates both to the initial notes and the exchange notes and is a
summary of the material provisions of the indenture and the security agreement.
It does not restate those agreements in their entirety. We urge you to read the
indenture and the security agreement because they, and not this description,
define your rights as holder of the exchange notes. We have filed copies of the
indenture and the security agreement as exhibits to the registration statement
which includes this Prospectus. The definitions of certain terms used in the
following summary are indicated below under "--Certain Definitions." For
purposes of this summary, the term "Metromedia Fiber Network" refers only to
Metromedia Fiber Network, Inc. and not to any of its Subsidiaries. Also, in this
description "initial notes" and "exchange notes" are collectively referred to as
the "notes."
    
 
   
    As of the Issue Date, all of our Subsidiaries will be Restricted
Subsidiaries. Under certain circumstances, we will be able to designate existing
or future Subsidiaries as Unrestricted Subsidiaries. Unrestricted Subsidiaries
will not be subject to many of the restrictive covenants contained in the
indenture. Our investment in ION and our investment in the joint venture
constructing the German network will not be considered Subsidiaries for purposes
of the indenture.
    
 
TERMS OF NOTES
 
   
    The notes:
    
 
   
    - are general obligations of Metromedia Fiber Network,
    
 
   
    - rank without preference in right of payment with all existing and future
      unsecured senior Indebtedness of Metromedia Fiber Network,
    
 
   
    - rank senior in right of payment to all subordinated Indebtedness of
      Metromedia Fiber Network that may be issued in the future, if any, and
    
 
   
    - are not secured by any assets, and, therefore, will be effectively
      subordinated to any existing and future secured Indebtedness of Metromedia
      Fiber Network and its Subsidiaries, including the Credit Agreement, to the
      extent of the value of the assets securing such Indebtedness.
    
 
   
    We conduct substantially all of our operations through our Subsidiaries and,
therefore, we are dependent on the cash flow of our Subsidiaries to meet our
obligations, including our obligations with respect to the notes. The notes will
be effectively subordinated to all Indebtedness and other liabilities and
commitments (including trade payables and lease obligations) of our
Subsidiaries, including any Guarantees of such Subsidiaries with respect to the
Credit Agreement. Any right of Metromedia Fiber Network to receive assets of any
of its Subsidiaries upon the liquidation or reorganization of such Subsidiary
(and the consequent right of the holders of the notes to participate in those
assets) will be effectively subordinated to the claims of that Subsidiary's
creditors, except to the extent that Metromedia Fiber Network is itself
recognized as a creditor of such Subsidiary. In such case the claims
    
 
                                       79
<PAGE>
   
of Metromedia Fiber Network would still be subordinate to any security in the
assets of such Subsidiary and any indebtedness of such Subsidiary that is senior
to that held by Metromedia Fiber Network. Please refer to the sections in this
Prospectus entitled "Risk Factors--Payment of Principal and Interest on the
Notes is Effectively Subordinated to the Claims of our Subsidiaries' Creditors."
    
 
PRINCIPAL, MATURITY AND INTEREST
 
   
    Metromedia Fiber Network will issue notes with a maximum aggregate principal
amount of $650.0 million. Metromedia Fiber Network will issue notes in
denominations of $1,000.00 and integral multiples of $1,000.00. For each initial
note accepted for exchange, the holder of such initial note will receive an
exchange note having a principal amount equal to that of the surrendered initial
note. The notes will mature on November 15, 2008.
    
 
   
    Interest on the exchange notes will accrue at the rate of 10% per year and
will be payable semi-annually in arrears on May 15 and November 15, commencing
on May 15, 1999. Metromedia Fiber Network will make each interest payment to the
holders of record of these notes on the immediately preceding May 1 and November
1.
    
 
   
    Interest on the exchange notes will accrue from the most recent date to
which interest has been paid on the initial notes or, if no interest has been
paid on the initial notes, from November 25, 1998. Accordingly, if the relevant
record date for interest payment occurs after the consummation of the exchange
offer, registered holders of exchange notes on such record date will receive
interest accruing from the most recent date to which interest has been paid on
the initial notes or, if no interest has been paid, from November 25, 1998.
Holders of initial notes whose initial notes are accepted for exchange will not
receive any payment in respect of interest on such initial notes otherwise
payable on any interest payment date the record date for which occurs on or
after the consummation of the exchange offer. If, however, the relevant record
date for interest payment occurs before the consummation of the exchange offer,
registered holders of initial notes on such record date will receive interest
accruing from the most recent date to which interest has been paid or, if no
interest has been paid, from November 25, 1998. Interest will cease to accrue on
initial notes accepted for exchange from and after the date of consummation of
the exchange offer, except as described in the immediately preceding sentence.
Interest is computed on the basis of a 360-day year comprised of twelve 30-day
months.
    
 
   
    If a holder has given wire transfer instructions to Metromedia Fiber
Network, Metromedia Fiber Network will make all payments of principal, premium,
if any, and interest on the notes to such holder by wire transfer of immediately
available funds in accordance with those instructions. All other payments of
principal, premium, if any, and interest on the notes are payable at the office
or agency of Metromedia Fiber Network maintained for such purpose within the
City and State of New York unless Metromedia Fiber Network has elected to pay
interest on the notes by check mailed to the holders of the notes at their
respective addresses set indicated in the register of holders of notes by the
holders. Until otherwise designated by Metromedia Fiber Network, Metromedia
Fiber Network's office or agency in New York will be the office of the trustee
maintained for such purpose.
    
 
PAYING AGENT AND REGISTRAR FOR THE NOTES
 
   
    The trustee initially will be the paying agent and registrar under the
indenture, and Metromedia Fiber Network may act as paying agent or registrar
under the indenture.
    
 
THE SECURITY AGREEMENT
 
   
    Metromedia Fiber Network's obligation to pay interest on the notes on May
15, 1999, November 15, 1999, and May 15, 2000 is secured by funds held by IBJ
Whitehall Bank & Trust Company, as security agent under an agreement between
Metromedia Fiber Network and the security
    
 
                                       80
<PAGE>
   
agent. Concurrently with the closing of the offering of the initial notes,
Metromedia Fiber Network deposited with the security agent in the security
account approximately $91.5 million in U.S. Government Securities, that,
together with the proceeds from the investment thereof, will be sufficient to
pay when due the first three interest payments on the notes. Following the third
interest payment on the notes, any amounts remaining in the security account
will be released to Metromedia Fiber Network and will thereafter remain subject
to the applicable provisions of the indenture.
    
 
OPTIONAL REDEMPTION
 
   
    Except as set forth below, the notes will not be redeemable at Metromedia
Fiber Network's option prior to November 15, 2003.
    
 
   
    After November 15, 2003, Metromedia Fiber Network may redeem the notes, in
whole or in part, upon not less than 30 nor more than 60 days' notice, at the
redemption prices (expressed as percentages of principal amount) provided below,
plus accrued and unpaid interest (and liquidated damages, if any) thereon to the
applicable redemption date (subject to the right of holders of record on the
relevant record date to receive interest due on the relevant interest payment
date), if redeemed during the twelve-month period beginning on November 15 of
the years indicated below:
    
 
<TABLE>
<CAPTION>
YEAR                                                                     PERCENTAGE
- -----------------------------------------------------------------------  -----------
<S>                                                                      <C>
2003...................................................................     105.000%
2004...................................................................     103.333%
2005...................................................................     101.667%
2006 and thereafter....................................................     100.000%
</TABLE>
 
   
    Notwithstanding the foregoing, at any time prior to November 15, 2001,
Metromedia Fiber Network may, on any one or more occasions, redeem up to 35% of
the aggregate principal amount of notes originally issued pursuant to the
indenture at a redemption price of 110% of the principal amount thereof, plus
accrued and unpaid interest (and liquidated damages, if any) thereon to the
redemption date (subject to the right of holders of record on the relevant
record date to receive interest due on the relevant interest payment date), if:
    
 
   
    - Metromedia Fiber Network uses the Net Cash Proceeds received from any
      Public Equity Offering made by Metromedia Fiber Network resulting in gross
      proceeds to Metromedia Fiber Network of at least $100 million, and
    
 
   
    - at least 65% of the aggregate principal amount of the notes originally
      issued pursuant to the Indenture remain outstanding immediately after the
      occurrence of any such redemption.
    
 
   
    Metromedia Fiber Network may make any such redemption upon not less than 30
nor more than 60 days' notice (but in no event more than 90 days after the
closing of the related Public Equity Offering).
    
 
SELECTION AND NOTICE
 
   
    If less than all of the notes are to be redeemed at any time, the trustee
will select notes for redemption as follows:
    
 
   
    - in compliance with the requirements of the principal national securities
      exchange, if any, on which the notes are then listed, or
    
 
   
    - if the notes are not so then listed, on a pro rata basis, by lot or by
      such method as Metromedia Fiber Network deems fair and appropriate.
    
 
                                       81
<PAGE>
   
    No notes of $1,000 or less shall be redeemed in part. Notices of redemption
shall be mailed by first class mail at least 30 but not more than 60 days before
the redemption date to each holder of notes to be redeemed at its registered
address. Notices of redemption may not be conditional.
    
 
   
    If any note is to be redeemed in part only, the notice of redemption that
relates to such note shall state the portion of the principal amount of such
note to be redeemed. A new note in principal amount equal to the unredeemed
portion of such note will be issued in the name of the Holder of such original
note upon cancellation of the original note. Notes called for redemption will
become due on the date fixed for redemption. On and after the redemption date,
interest will cease to accrue on notes or portions thereof called for redemption
unless Metromedia Fiber Network defaults in the payment of such interest.
    
 
MANDATORY REDEMPTION
 
   
    Metromedia Fiber Network is not be required to make mandatory redemption or
sinking fund payments with respect to the notes.
    
 
REPURCHASE AT THE OPTION OF HOLDERS
 
    CHANGE OF CONTROL
 
   
    If a Change of Control occurs, each holder of notes will have the right to
require Metromedia Fiber Network to purchase all or any part (equal to $1,000 or
an integral multiple thereof) of that Holder's notes pursuant to the offer
described below (the "Change of Control Offer") at a purchase price in cash
equal to 101% of the aggregate principal amount thereof (the "Change of Control
Payment"), plus accrued and unpaid interest (and liquidated damages, if any)
thereon to the date of purchase (subject to the right of Holders of record on
the relevant record date to receive interest due on the relevant interest
payment date). However, Metromedia Fiber Network shall not be obligated to
repurchase notes pursuant to a Change of Control Offer if it has exercised its
rights to redeem all of the notes pursuant to the indenture. Within 30 days
following any Change of Control, Metromedia Fiber Network will mail a notice to
each holder describing the transaction or transactions that constitute the
Change of Control and offering to purchase notes on the date specified in such
notice, which date shall be no earlier than 30 and no later than 60 days from
the date such notice is mailed (the "Change of Control payment date"), in
accordance with the procedures required by the Indenture and described in such
notice.
    
 
   
    Metromedia Fiber Network will comply with the requirements of Rule 14e-1
under the Securities Exchange Act of 1934 and any other securities laws and
regulations to the extent such laws and regulations are applicable in connection
with the purchase of notes as a result of a Change of Control. To the extent
that the provisions of any securities laws or regulations conflict with any of
the provisions of this covenant, Metromedia Fiber Network will comply with the
applicable securities laws and regulations and will be deemed not to have
breached its obligations under this covenant by virtue thereof.
    
 
   
    On the Change of Control payment date, Metromedia Fiber Network will, to the
extent lawful:
    
 
   
    - accept for payment all notes or portions thereof properly tendered
      pursuant to the Change of Control Offer,
    
 
   
    - deposit with the paying agent an amount equal to the Change of Control
      Payment plus accrued and unpaid interest thereon and liquidated damages,
      if any, in respect of all notes or portions thereof so tendered, and
    
 
                                       82
<PAGE>
   
    - deliver or cause to be delivered to the trustee notes so accepted together
      with an Officer's Certificate stating the aggregate principal amount of
      notes or portions thereof being purchased by Metromedia Fiber Network.
    
 
   
    The paying agent will promptly mail or deliver to each holder of notes so
tendered the Change of Control payment plus accrued and unpaid interest thereon
and liquidated damages, if any, for such notes, and the trustee will promptly
authenticate and mail or deliver (or cause to be transferred by book entry) to
each holder a new note in principal amount equal to any unpurchased portion of
notes surrendered, if any; PROVIDED that each such new note will be in a
principal amount of $1,000 or an integral multiple thereof. Metromedia Fiber
Network will publicly announce the results of the Change of Control Offer on or
as soon as practicable after the Change of Control payment date.
    
 
   
    The Change of Control provisions described above will be applicable whether
or not any other provisions of the indenture are applicable. Except as described
above with respect to a Change of Control, the indenture does not contain
provisions that permit the Holders of the notes to require that Metromedia Fiber
Network purchase or redeem the notes in the event of a takeover,
recapitalization or similar transaction.
    
 
   
    Metromedia Fiber Network's ability to purchase notes upon a Change of
Control may be limited by Metromedia Fiber Network's then existing financial
resources. We cannot assure you that sufficient funds will be available when
necessary to make any such required purchases. Metromedia Fiber Network will not
be required to make a Change of Control Offer if a third party makes the Change
of Control Offer in the manner, at the times and otherwise in compliance with
the requirements of the indenture and purchases all notes validly tendered and
not withdrawn.
    
 
    ASSET SALES
 
   
    Metromedia Fiber Network will not, and will not permit any of its Restricted
Subsidiaries to, directly or indirectly, consummate any Asset Sale, unless:
    
 
   
    (i) Metromedia Fiber Network (or such Restricted Subsidiary, as the case may
        be) receives consideration at the time of such Asset Sale at least equal
        to the fair market value of the assets or Equity Interests issued or
        sold or otherwise disposed of. For purposes of this covenant, fair
        market value will be as determined in good faith by the Board of
        Directors (including as to the value of all non cash consideration) and
        set forth in an Officer's Certificate delivered to the trustee,
    
 
    (ii) at least 75% of the consideration therefor is in the form of cash
         and/or Cash Equivalents or Telecommunications Assets, and
 
   
   (iii) Metromedia Fiber Network (or such Restricted Subsidiary, as the case
         may be) applies the Net Proceeds received from such Asset Sale within
         360 days following the receipt of such Net Cash Proceeds, to the extent
         Metromedia Fiber Network elects:
    
 
   
        (a) to the permanent redemption or repurchase of outstanding
            Indebtedness (other than Subordinated Indebtedness) that is secured
            Indebtedness (including that in the case of a revolver or similar
            arrangement that makes credit available, such commitment is so
            permanently reduced by such amount), or Indebtedness of Metromedia
            Fiber Network or such Restricted Subsidiary that ranks equally with
            the notes but has a maturity date that is prior to the maturity date
            of the notes, and/or
    
 
        (b) to reinvest such Net Cash Proceeds (or any portion thereof) in
            Telecommunications Assets.
 
    Notwithstanding anything herein to the contrary, with respect to the
reinvestment of Net Cash Proceeds, only proceeds from an Asset Sale of assets,
or Equity Interests, of a Foreign Subsidiary may
 
                                       83
<PAGE>
be used to retire Indebtedness of a Foreign Subsidiary or reinvest in assets or
Equity Interests of a Foreign Subsidiary.
 
    The balance of the Net Cash Proceeds that are not applied or invested as
described in the immediately preceding clauses (a) and (b), shall constitute
"Excess Proceeds."
 
   
    When the aggregate amount of excess proceeds equals or exceeds $15.0 million
(taking into account income earned on such excess proceeds), Metromedia Fiber
Network will be required to make a pro rata offer to all holders of notes and
PARI PASSU Indebtedness with comparable provisions requiring such Indebtedness
to be purchased with the proceeds of such Asset Sale (an "Asset Sale Offer") to
purchase the maximum principal amount or accreted value in the case of
Indebtedness issued with an original issue discount of notes and PARI PASSU
Indebtedness that may be purchased out of the excess proceeds, at a purchase
price in cash in an amount equal to 100% of the principal amount thereof or the
accreted value thereof, as applicable, plus accrued and unpaid interest thereon
to the date of purchase (subject to the right of holders of record on the
relevant record date to receive interest due on the relevant interest payment
date), in accordance with the procedures set forth in the indenture and the
agreements governing such PARI PASSU Indebtedness. To the extent that any excess
proceeds remain after consummation of an Asset Sale Offer, Metromedia Fiber
Network may use such excess proceeds for any purpose not otherwise prohibited by
the indenture. If the aggregate principal amount of notes and PARI PASSU
Indebtedness tendered into such Asset Sale offer surrendered by holders thereof
exceeds the amount of Excess Proceeds, the Trustee shall select the notes and
PARI PASSU Indebtedness to be purchased on a pro rata basis in proportion to the
respective principal amounts (or accreted values in the case of Indebtedness
issued with an original issue discount) of the notes and such other
Indebtedness. Upon completion of such Asset Sale offer, the amount of excess
proceeds shall be reset at zero for purposes of the first sentence of this
paragraph.
    
 
    For purposes of this provision, the following amounts will be deemed to be
cash and/or Cash Equivalents:
 
   
    (i) any liabilities (as shown on Metromedia Fiber Network's (or such
        Restricted Subsidiary's, as the case may be), most recent balance
        sheet), other than Subordinated Indebtedness, of Metromedia Fiber
        Network or any Restricted Subsidiary, that are assumed by the transferee
        of any such assets pursuant to an agreement that immediately releases
        Metromedia Fiber Network and all of its Restricted Subsidiaries from all
        liability in respect thereof,
    
 
   
    (ii) Indebtedness of any Restricted Subsidiary that is no longer a
         Restricted Subsidiary as a result of such Asset Sale, if Metromedia
         Fiber Network and all of its Restricted Subsidiaries immediately are
         released from all Guarantees of payment of such Indebtedness and such
         Indebtedness is no longer the liability of Metromedia Fiber Network or
         any of its Restricted Subsidiaries, and
    
 
   
   (iii) any securities, notes or other obligations received by Metromedia Fiber
         Network (or such Restricted Subsidiary, as the case may be) from such
         transferee that are contemporaneously (subject to ordinary settlement
         periods) converted by Metromedia Fiber Network (or such Restricted
         Subsidiary, as the case may be) into cash and/or Cash Equivalents (to
         the extent of the cash and/or Cash Equivalents received).
    
 
                                       84
<PAGE>
CERTAIN COVENANTS
 
   
    The indenture imposes certain covenants on Metromedia Fiber Network,
including the following covenants:
    
 
    RESTRICTED PAYMENTS
 
   
    Metromedia Fiber Network will not, and will not permit any of its Restricted
Subsidiaries to, directly or indirectly:
    
 
   
    (i) declare or pay any dividend or make any other payment or distribution on
account of Metromedia Fiber Network's or any of its Restricted Subsidiaries'
Equity Interests or to the direct or indirect holders of Metromedia Fiber
Network's or any of its Restricted Subsidiaries' Equity Interests in their
capacity as stockholders (other than dividends or distributions payable in
Equity Interests (other than Disqualified Stock) of Metromedia Fiber Network or
to Metromedia Fiber Network or a Restricted Subsidiary of Metromedia Fiber
Network),
    
 
   
    (ii) purchase, redeem or otherwise acquire or retire for value any Equity
Interests of Metromedia Fiber Network or any of its Restricted Subsidiaries or
any direct or indirect parent of Metromedia Fiber Network (other than any such
Equity Interests owned by Metromedia Fiber Network or any Consolidated
Subsidiary of Metromedia Fiber Network),
    
 
    (iii) make any payment on or with respect to, or purchase, redeem, defease
or otherwise acquire or retire for value any Subordinated Indebtedness, except a
payment of interest or principal at Stated Maturity, or
 
   
    (iv) make any Restricted Investment (all such payments and other actions set
forth in clauses (i) through (iv) above being collectively referred to as
"restricted payments"), unless:
    
 
   
    (a) at the time of and after giving effect to such restricted payment, no
        Default or Event of Default shall have occurred and be continuing or
        would occur as a consequence thereof,
    
 
   
    (b) Metromedia Fiber Network would, at the time of such Restricted Payment
        and after giving pro forma effect thereto as if such Restricted Payment
        had been made at the beginning of the applicable period, have been
        permitted to incur at least $1.00 of additional Indebtedness pursuant to
        either clause (i) or (ii) of the first paragraph of the covenant
        described below under the caption "--Incurrence of Indebtedness and
        Issuance of Preferred Stock", and
    
 
   
    (c) such Restricted Payment, together with the aggregate amount of all other
        Restricted Payments made by Metromedia Fiber Network and its Restricted
        Subsidiaries on and after the Issue Date (excluding Restricted Payments
        permitted by, and made pursuant to, clauses (ii), (iii) and (viii) of
        the next succeeding paragraph), is less than the sum, without
        duplication and except as credited in the next succeeding paragraph, of:
    
 
   
        (i) 50% of the Consolidated Net Income of Metromedia Fiber Network for
            the period (taken as one accounting period) beginning on the last
            day of the fiscal quarter immediately preceding the Issue Date and
            ending on the last day of the fiscal quarter immediately preceding
            the date of such Restricted Payment (or, if such Consolidated Net
            Income for such period is a deficit, less 100% of such deficit),
            plus
    
 
   
        (ii) 100% of the aggregate Net Cash Proceeds received by Metromedia
             Fiber Network on and after the Issue Date as a Capital Contribution
             or from the issue or sale of Equity Interests of Metromedia Fiber
             Network (other than Disqualified Stock) or from the issue or sale
             of Disqualified Stock or debt securities of Metromedia Fiber
             Network that have been converted or exchanged into such Equity
             Interests (other than Equity Interests (or Disqualified Stock or
             converted debt securities) sold to a Subsidiary of Metromedia Fiber
    
 
                                       85
<PAGE>
   
             Network), plus the amount of Net Cash Proceeds received by
             Metromedia Fiber Network upon such conversion or exchange, plus
    
 
   
       (iii) the aggregate amount equal to the net reduction in Investments in
             Unrestricted Subsidiaries on and after the Issue Date resulting
             from (x) dividends, distributions, interest payments, return of
             capital, repayments of Investments or other transfers of assets to
             Metromedia Fiber Network or any Restricted Subsidiary from any
             Unrestricted Subsidiary, (y) proceeds realized by Metromedia Fiber
             Network or any Restricted Subsidiary upon the sale of such
             Investment to a Person other than Metromedia Fiber Network or any
             Subsidiary of Metromedia Fiber Network, or (z) the redesignation of
             any Unrestricted Subsidiary as a Restricted Subsidiary, not to
             exceed in the case of any of the immediately preceding clauses (x),
             (y) or (z) the aggregate amount of Restricted Investments made by
             Metromedia Fiber Network or any Restricted Subsidiary in such
             Unrestricted Subsidiary on and after the Issue Date, plus
    
 
   
        (iv) to the extent that any Restricted Investment that was made on and
             after the Issue Date is sold for cash or otherwise liquidated or
             repaid for cash, the lesser of, to the extent paid to Metromedia
             Fiber Network or a Restricted Subsidiary, (A) the cash return of
             capital with respect to such Restricted Investment (less the cost
             of disposition, if any) and (B) the initial amount of such
             Restricted Investment.
    
 
    The foregoing provisions will not prohibit:
 
    (i) the payment of any dividend within 60 days after the date of declaration
thereof, if at said date of declaration such payment would have complied with
the foregoing provisions;
 
   
    (ii) the redemption, repurchase, retirement, defeasance or other acquisition
of any Subordinated Indebtedness or Equity Interests of Metromedia Fiber Network
in exchange for, or out of the Net Cash Proceeds of the substantially concurrent
sale (other than to a Subsidiary of Metromedia Fiber Network) of, Equity
Interests of Metromedia Fiber Network (other than any Disqualified Stock);
PROVIDED that the amount of any such Net Cash Proceeds that are utilized for,
and the Equity Interests issued or exchanged for, any such redemption,
repurchase, retirement, defeasance or other acquisition shall be excluded from
clause (c) of the preceding paragraph and each other clause of this paragraph;
    
 
    (iii) the defeasance, redemption, retirement, repurchase or other
acquisition of Subordinated Indebtedness with the Net Cash Proceeds from, or
issued in exchange for, a substantially concurrent incurrence of Permitted
Refinancing Indebtedness; PROVIDED that the amount of any such Net Cash Proceeds
that are utilized for any such redemption, repurchase, retirement, defeasance or
other acquisition shall be excluded from clause (c) of the preceding paragraph
and each other clause of this paragraph;
 
   
    (iv) the payment of any dividend or other distribution by a Restricted
Subsidiary of Metromedia Fiber Network to the holders of its Equity Interests on
a pro rata basis;
    
 
   
    (v) the repurchase, redemption or other acquisition or retirement for value
of any Equity Interests of Metromedia Fiber Network or any of its Restricted
Subsidiaries held by any member of Metromedia Fiber Network's or such Restricted
Subsidiary's management; PROVIDED that the aggregate price paid for all such
repurchased, redeemed, acquired or retired Equity Interests shall not exceed
$1.0 million in any fiscal year;
    
 
   
    (vi) retiring any Equity Interests of Metromedia Fiber Network to the extent
necessary (as determined in good faith by a majority of the disinterested
members of the Board of Directors, whose determination shall be evidenced by a
resolution thereof) to prevent the loss, or to secure the renewal or
reinstatement, of any license or franchise held by Metromedia Fiber Network or
any Restricted Subsidiary from any governmental agency;
    
 
                                       86
<PAGE>
   
    (vii) Investments in Telecommunications Assets, PROVIDED that the aggregate
fair market value (measured on the date each such Investment was made or
returned, as applicable), when taken together with all other Investments made
pursuant to this clause (vii) that are at the time outstanding, does not exceed
the sum of (y) $15.0 million, plus (z) the aggregate amount equal to the net
reduction in Investments made pursuant to this clause (vii) on and after the
Issue Date resulting from dividends, distributions, interest payments, return of
capital, repayments of such Investments or Net Cash Proceeds realized by
Metromedia Fiber Network or any Restricted Subsidiary upon the sale of such
Investment to a Person other than Metromedia Fiber Network or any Subsidiary of
Metromedia Fiber Network, except to the extent any such net reduction amount is
included in the amount calculated pursuant to clause (c) of the preceding
paragraph or any other clause of this paragraph;
    
 
   
    (viii) Investments in Telecommunications Assets made with the Net Cash
Proceeds, the fair market value of Telecommunications Assets or Equity Interests
of a Person that becomes a Restricted Subsidiary (PROVIDED the assets of such
Person consist entirely or substantially entirely of Telecommunications Assets)
received from the sale (other than to a Subsidiary of Metromedia Fiber Network)
of Equity Interests of Metromedia Fiber Network (other than any Disqualified
Stock) and, PROVIDED, FURTHER, that the amount of any such Net Cash Proceeds
that are utilized for any such Investment shall be excluded from clause (c) of
the preceding paragraph and each other clause of this paragraph;
    
 
   
    (ix) Investments in ION, PROVIDED that the aggregate fair market value
thereof (measured on the date each such Investment was made or returned, as
applicable), when taken together with all other Investments made pursuant to
this clause (ix) does not exceed the sum of (I) $15.0 million, plus, (II) for
each fiscal year, an amount equal to the amount of cash received by Metromedia
Fiber Network or any of its Restricted Subsidiaries from ION or any of its
Subsidiaries during such fiscal year except to the extent any such amount is
included in the amount calculated pursuant to clause (c) of the preceding
paragraph or any other clause of this paragraph during such fiscal year plus,
(III) to the extent necessary to pay reasonable and necessary operating expenses
of ION, an amount not to exceed $1.0 million in each fiscal year; and
    
 
   
    (x) Investments in the German Joint Venture, PROVIDED that the aggregate
fair market value (measured on the date each such Investment was made or
returned, as applicable), when taken together with all other Investments made
pursuant to this clause (x) that are at the time outstanding, does not exceed
the sum of (I) $100.0 million, plus (II) the aggregate amount equal to the net
reduction in Investments made pursuant to this clause (x) on and after the Issue
Date resulting from dividends, distributions, interest payments, return of
capital, repayments of such Investments or Net Cash Proceeds realized by
Metromedia Fiber Network or any Restricted Subsidiary upon the sale of such
Investment to a Person other than Metromedia Fiber Network or any Subsidiary of
Metromedia Fiber Network, except to the extent such amount is included in the
amount calculated pursuant to clause (c) of the preceding paragraph or any other
clause of this paragraph.
    
 
   
    The Board of Directors may not designate any Subsidiary of Metromedia Fiber
Network (other than a newly created Subsidiary in which no Investment has
previously been made (other than any de minimus amount required to capitalize
such Subsidiary in connection with its organization)) as an Unrestricted
Subsidiary (a "designation") unless:
    
 
   
    (i) no Default or Event of Default shall have occurred and be continuing at
the time of or after giving effect to such designation;
    
 
   
    (ii) Metromedia Fiber Network would, immediately after giving effect to such
designation, have been permitted to incur at least $1.00 of additional
Indebtedness pursuant to either clause (i) or (ii) of the first paragraph of the
covenant described below under the caption "--Incurrence of Indebtedness and
Issuance of Preferred Stock"; and
    
 
                                       87
<PAGE>
   
    (iii) Metromedia Fiber Network would not be prohibited under the indenture
from making an Investment at the time of such designation (assuming the
effectiveness of such designation for purposes of this covenant) in an amount
equal to the fair market value of the net Investment of Metromedia Fiber Network
and all Restricted Subsidiaries in such Subsidiary on such date.
    
 
   
    In the event of any such designation, all outstanding Investments owned by
Metromedia Fiber Network and its Restricted Subsidiaries in the Subsidiary so
designated will be deemed to be an Investment made as of the time of such
designation and will reduce the amount available for Restricted Payments under
the first or second paragraph of this covenant or Investments, as applicable.
All such outstanding Investments will be deemed to constitute Restricted
Payments in an amount equal to the fair market value of such Investments at the
time of such designation.
    
 
   
    The indenture will further provide that a designation may be revoked and an
Unrestricted Subsidiary may thus be redesignated as a Restricted Subsidiary (a
"revocation") by a resolution of the Board of Directors delivered to the
Trustee; PROVIDED that Metromedia Fiber Network will not make any Revocation
unless:
    
 
   
    (i) no Default or Event of Default shall have occurred and be continuing at
the time of or after giving effect to such designation; and
    
 
   
    (ii) all Liens and Indebtedness of such Unrestricted Subsidiary outstanding
immediately following such revocation would, if incurred at such time, have been
permitted to be incurred at such time for all purposes under the indenture.
    
 
   
    The amount of all Restricted Payments (other than cash) shall be the fair
market value on the date of the Restricted Payment of the asset(s) or securities
proposed to be transferred or issued by Metromedia Fiber Network (or such
Restricted Subsidiary, as the case may be) pursuant to the Restricted Payment.
The fair market value of any asset(s) or securities that are required to be
valued by this covenant shall be determined in good faith by the Board of
Directors (such determination to be based upon an opinion or appraisal issued by
an accounting, appraisal or investment banking firm of national standing if such
fair market value exceeds $15.0 million).
    
 
    INCURRENCE OF INDEBTEDNESS AND ISSUANCE OF PREFERRED STOCK
 
   
    Metromedia Fiber Network will not, and will not permit any of its Restricted
Subsidiaries to, directly or indirectly, create, incur, issue, assume, guarantee
or otherwise become directly or indirectly liable, contingently or otherwise
(including by way of merger, consolidation or acquisition), with respect to
(collectively, "incur") any Indebtedness and Metromedia Fiber Network will not
issue or incur any Disqualified Stock and will not permit any of its Restricted
Subsidiaries to issue or incur any shares of Preferred Stock. However,
Metromedia Fiber Network may incur Indebtedness or issue or incur shares of
Disqualified Stock and its Restricted Subsidiaries may incur Acquired Debt or
Acquired Preferred Stock if either:
    
 
   
    (i) the Consolidated Leverage Ratio at the end of Metromedia Fiber Network's
most recently ended fiscal quarter (the "reference period") for which a
consolidated balance sheet of Metromedia Fiber Network is available immediately
preceding the date on which such additional Indebtedness is incurred or such
Preferred Stock is issued or incurred would have been less than 5.5 to 1.0 (if
the reference period ends on or prior to December 31, 2001), or 5.0 to 1.0 (if
the reference period ends subsequent to December 31, 2001), determined on a pro
forma basis (including a pro forma application of the net proceeds therefrom),
as if the additional Indebtedness had been incurred, or the Preferred Stock had
been issued, as the case may be, at the beginning of the reference period; or
    
 
   
    (ii) the Consolidated Capital Ratio at the end of the reference period would
have been less than 2.0 to 1.0, determined after giving effect to the incurrence
or issuance of such Indebtedness or
    
 
                                       88
<PAGE>
Preferred Stock and, to the extent set forth in the definitions used herein, on
a pro forma basis (including a pro forma application of the net proceeds
therefrom).
 
   
    Notwithstanding the foregoing, the provisions of the paragraph set forth
immediately above will not prohibit the incurrence of any of the following items
of Indebtedness (collectively, "permitted indebtedness"):
    
 
   
    (a) the incurrence by Metromedia Fiber Network of Indebtedness represented
       by the notes;
    
 
   
    (b) the incurrence by Metromedia Fiber Network or any of its Restricted
       Subsidiaries of Existing Indebtedness;
    
 
   
    (c) the incurrence of Indebtedness by Metromedia Fiber Network to any
       Consolidated Subsidiary or Indebtedness of any Restricted Subsidiary to
       Metromedia Fiber Network or any Consolidated Subsidiary (but such
       Indebtedness shall be deemed to be incurred upon such Indebtedness being
       held by any person other than Metromedia Fiber Network or such
       Consolidated Subsidiary including upon Designation and upon such
       Restricted Subsidiary otherwise no longer being a Consolidated
       Subsidiary); PROVIDED that in the case of Indebtedness of Metromedia
       Fiber Network, such obligations shall be unsecured and subordinated in
       all respects to Metromedia Fiber Network's obligations pursuant to the
       notes;
    
 
   
    (d) the incurrence by Metromedia Fiber Network of Indebtedness in an
       aggregate amount incurred and outstanding at any time pursuant to this
       clause (d) (plus any Permitted Refinancing Indebtedness and any other
       Indebtedness incurred to retire, defease, refinance, replace or refund
       such Indebtedness) of up to $25.0 million;
    
 
   
    (e) the incurrence by Metromedia Fiber Network, or any Guarantee thereof by
       any Restricted Subsidiary (other than any Foreign Subsidiary), of
       Indebtedness pursuant to the Credit Agreement in an aggregate amount
       incurred and outstanding at any time pursuant to this clause (e) (plus
       any Permitted Refinancing Indebtedness and any other Indebtedness
       incurred to retire, defease, refinance, replace or refund such
       Indebtedness) of up to $150.0 million, minus the amount of any such
       Indebtedness (i) retired with the Net Cash Proceeds from any Asset Sale
       applied to permanently reduce the outstanding amounts or the commitments
       with respect to such Indebtedness pursuant to the covenant "Asset Sales"
       or (ii) assumed by a transferee in an Asset Sale;
    
 
   
    (f) the incurrence by Metromedia Fiber Network or any Foreign Subsidiaries
       of Purchase Money Indebtedness; PROVIDED that in each case, such
       Indebtedness shall not constitute more than 100% of the cost (determined
       in accordance with GAAP in good faith by the Board of Directors of
       Metromedia Fiber Network) to Metromedia Fiber Network or such Foreign
       Subsidiary, as applicable, of the property so purchased, developed,
       acquired, constructed, improved or leased;
    
 
   
    (g) the incurrence by Metromedia Fiber Network or any of its Restricted
       Subsidiaries of Hedging Obligations that are incurred for the purpose of
       fixing or hedging interest or foreign currency exchange rate risk with
       respect to any floating rate Indebtedness or foreign currency based
       Indebtedness, respectively, that is permitted by the terms of the
       indenture to be outstanding; PROVIDEDthat the notional amount of any such
       Hedging Obligation does not exceed the amount of Indebtedness or other
       liability to which such Hedging Obligation relates;
    
 
    (h) the incurrence by a Foreign Subsidiary of Indebtedness pursuant to a
       Foreign Subsidiary Credit Agreement (or any Guarantee thereof by any
       other Foreign Subsidiary) in an aggregate principal amount incurred and
       outstanding at any time pursuant to this clause (h) (plus any Permitted
       Refinancing Indebtedness and any other Indebtedness incurred to retire,
       defease, refinance, replace or refund such Indebtedness) of up to $50.0
       million (or the equivalent
 
                                       89
<PAGE>
       thereof at the time of incurrence in the applicable foreign currencies),
       minus the amount of any such Indebtedness (i) retired with the Net Cash
       Proceeds from any Asset Sale applied to permanently reduce the
       outstanding amounts or the commitments with respect to such Indebtedness
       pursuant to the covenant "Asset Sales" or (ii) assumed by a transferee of
       an Asset Sale;
 
   
    (i) Metromedia Fiber Network and its Restricted Subsidiaries may incur
       Indebtedness solely in respect of bankers acceptances, letters of credit
       and performance bonds, all in the ordinary course of business in
       accordance with customary industry practices, in amounts and for the
       purposes customary in Metromedia Fiber Network's industry (other than to
       the extent not supporting Indebtedness); and
    
 
   
    (j) the incurrence by Metromedia Fiber Network or any of its Restricted
       Subsidiaries, as applicable, of Permitted Refinancing Indebtedness in
       exchange for, or the net proceeds of which are used to, refund, refinance
       or replace Indebtedness that was incurred pursuant to the first paragraph
       hereof or clauses (a), (b), (d), (e), (f), (h) or this clause (j) of this
       paragraph.
    
 
   
    Indebtedness or Preferred Stock of any Person which is outstanding at the
time such Person becomes a Restricted Subsidiary of Metromedia Fiber Network
(including upon designation of any Subsidiary or other Person as a Restricted
Subsidiary or upon a revocation such that such Subsidiary becomes a Restricted
Subsidiary) or is merged with or into or consolidated with Metromedia Fiber
Network or a Restricted Subsidiary of Metromedia Fiber Network shall be deemed
to have been incurred at the time such Person becomes such a Restricted
Subsidiary of Metromedia Fiber Network or is merged with or into or consolidated
with Metromedia Fiber Network or a Restricted Subsidiary of Metromedia Fiber
Network, as applicable.
    
 
   
    Upon each incurrence, Metromedia Fiber Network may designate pursuant to
which provision of this covenant such Indebtedness is being incurred and such
Indebtedness shall not be deemed to have been incurred by Metromedia Fiber
Network under any other provision of this covenant, except as stated otherwise
in the foregoing provisions.
    
 
   
    Metromedia Fiber Network will not, and will not permit any of its Restricted
Subsidiaries to, incur any Indebtedness (including Permitted Indebtedness) that
is contractually subordinated in right of payment to any other Indebtedness of
Metromedia Fiber Network unless such Indebtedness is also contractually
subordinated in right of payment to the notes on substantially identical terms;
PROVIDED, HOWEVER, that no Indebtedness of Metromedia Fiber Network shall be
deemed to be contractually subordinated in right of payment to any other
Indebtedness of Metromedia Fiber Network solely by virtue of being unsecured.
    
 
    LIENS
 
   
    Metromedia Fiber Network will not, and will not permit any of its Restricted
Subsidiaries to, directly or indirectly, create, incur, assume or otherwise
cause or suffer to exist or become effective any Lien of any kind (other than
Permitted Liens) upon any of their property or assets, now owned or hereafter
acquired, or upon any income or profits therefrom unless all payments due under
the indenture and the notes are secured (except as provided in the next clause)
on an equal and ratable basis with the obligations so secured and no Lien shall
be granted or be allowed to exist which secures Subordinated Indebtedness except
with respect to Acquired Debt, in which case, however, such Liens must be made
junior and subordinate to the Liens granted to the holders of the notes.
    
 
                                       90
<PAGE>
    DIVIDEND AND OTHER PAYMENT RESTRICTIONS AFFECTING RESTRICTED SUBSIDIARIES
 
   
    Metromedia Fiber Network will not, and will not permit any of its Restricted
Subsidiaries to, directly or indirectly, create or otherwise cause or suffer to
exist or become effective any encumbrance or restriction on the ability of any
Restricted Subsidiary to:
    
 
   
    (i) (a) pay dividends or make any other distributions to Metromedia Fiber
Network or any of its Restricted Subsidiaries (y) on its Capital Stock or (z)
with respect to any other interest or participation in, or measured by, its
profits, or
    
 
   
       (b) pay any indebtedness owed to Metromedia Fiber Network or any of its
           Restricted Subsidiaries,
    
 
   
    (ii) make loans or advances to Metromedia Fiber Network or any of its
Restricted Subsidiaries or
    
 
   
    (iii) transfer any of its properties or assets to Metromedia Fiber Network
or any of its Restricted Subsidiaries.
    
 
    However, the foregoing restrictions will not apply to encumbrances or
restrictions existing under or by reason of:
 
    (a) Existing Indebtedness as in effect on the Issue Date,
 
   
    (b) the indenture, the notes and Indebtedness ranking PARI PASSU with the
       notes provided such provisions are no more restrictive than the notes,
    
 
   
    (c) the Credit Agreement, any Foreign Subsidiary Credit Agreement, PROVIDED
       that the restrictions contained in the Credit Agreement are no more
       restrictive, taken as a whole, than those contained in a credit agreement
       with terms that are commercially reasonable for a borrower that has
       substantially comparable Indebtedness, and PROVIDED, FURTHER, that no
       such provision shall prohibit or restrict the ability of any Restricted
       Subsidiary to pay dividends or make other upstream distributions or other
       payments to Metromedia Fiber Network or any of its Restricted
       Subsidiaries,
    
 
    (d) applicable law,
 
   
    (e) any instrument governing Indebtedness or Capital Stock of a Person or
       assets acquired by Metromedia Fiber Network or any of its Restricted
       Subsidiaries as in effect at the time of such acquisition (except to the
       extent such Indebtedness was incurred in connection with or in
       contemplation of such acquisition), which encumbrance or restriction is
       not applicable to any Person, or the properties or assets of any Person,
       other than the Person, or the property or assets of the Person, so
       acquired; PROVIDED, that in the case of Indebtedness, such Indebtedness
       was permitted by the terms of the indenture to be incurred,
    
 
    (f) customary non-assignment provisions in leases entered into in the
       ordinary course of business and consistent with past practices,
 
    (g) purchase money obligations (including pursuant to Purchase Money
       Indebtedness obligations) for property acquired in the ordinary course of
       business that impose restrictions of the nature described in clause (iii)
       above on the property so acquired, constructed, leased or improved,
 
    (h) any agreement for the sale or other disposition of a Restricted
       Subsidiary that restricts distributions by that Restricted Subsidiary
       pending its sale or other disposition, provided that the consummation of
       such transaction would not result in an Event of Default or an event
       that, with the passing of time or giving of notice or both, would
       constitute an Event of Default, that such restriction terminates if such
       transaction is not consummated and that the consummation or abandonment
       of such transaction occurs within one year of the date such agreement was
       entered into,
 
                                       91
<PAGE>
    (i) Permitted Refinancing Indebtedness, PROVIDED that the restrictions
       contained in the agreements governing such Permitted Refinancing
       Indebtedness are no more restrictive, taken as a whole, than those
       contained in the agreements governing the Indebtedness being extended,
       refinanced, renewed, replaced, defeased or refunded,
 
   
    (j) Liens securing Indebtedness otherwise permitted to be incurred pursuant
       to the provisions of the covenant described above under the caption
       "--Liens" that limit the right of Metromedia Fiber Network or any of its
       Restricted Subsidiaries to dispose of the assets subject to such Lien,
    
 
    (k) provisions with respect to the disposition or distribution of assets or
       property in joint venture agreements and other similar agreements entered
       into in the ordinary course of business, and
 
    (l) restrictions on cash or other deposits or net worth imposed by customers
       under contracts entered into in the ordinary course of business.
 
    MERGER, CONSOLIDATION, OR SALE OF ASSETS
 
   
    Metromedia Fiber Network may not, directly or indirectly, consolidate or
merge with or into (whether or not Metromedia Fiber Network is the surviving
corporation), or sell, assign, transfer, convey or otherwise dispose of all or
substantially all of its properties or assets, in one or more related
transactions, to another Person unless:
    
 
   
    (i) Metromedia Fiber Network is the surviving corporation or the Person
formed by or surviving any such consolidation or merger (if other than the
Company) or to which such sale, assignment, transfer, conveyance or other
disposition shall have been made is a corporation organized or existing under
the laws of the United States, any state thereof or the District of Columbia;
    
 
   
    (ii) the Person formed by or surviving any such consolidation or merger (if
other than Metromedia Fiber Network) or the Person to which such sale,
assignment, transfer, conveyance or other disposition shall have been made
assumes all the obligations of Metromedia Fiber Network under our registration
rights agreement, the notes and the indenture pursuant to a supplemental
indenture in a form reasonably satisfactory to the Trustee;
    
 
    (iii) no Default or Event of Default (or an event that, with the passing of
time or giving of notice or both, would constitute an Event of Default) shall
exist or shall occur immediately after giving effect on a pro forma basis to
such transaction;
 
   
    (iv) except in the case of a merger of Metromedia Fiber Network with or into
a Wholly Owned Restricted Subsidiary of Metromedia Fiber Network, Metromedia
Fiber Network or the Person formed by or surviving any such consolidation or
merger (if other than Metromedia Fiber Network), or to which such sale,
assignment, transfer, conveyance or other disposition shall have been made will
immediately after such transaction and after giving pro forma effect thereto and
any related financing transactions as if the same had occurred at the beginning
of the applicable period, be permitted to incur at least $1.00 of additional
Indebtedness pursuant to either clause (i) or (ii) of the first paragraph of the
covenant described above under the caption "--Incurrence of Indebtedness and
Issuance of Preferred Stock";
    
 
   
    (v) if, as a result of any such transaction, property or assets of
Metromedia Fiber Network would become subject to a Lien subject to the
provisions of the indenture described under "--Liens" above, Metromedia Fiber
Network or the successor entity to Metromedia Fiber Network shall have secured
the notes as required by said covenant; and
    
 
   
    (vi) Metromedia Fiber Network shall have delivered to the Trustee an
Officers' Certificate and an opinion of counsel, each stating that such
consolidation, merger or transfer and such supplemental indenture (if any)
comply with the indenture.
    
 
                                       92
<PAGE>
   
    The indenture will also provide that Metromedia Fiber Network may not,
directly or indirectly, lease all or substantially all of its properties or
assets, in one or more related transactions, to any other Person. The provisions
of this covenant will not be applicable to a sale, assignment, transfer,
conveyance or other disposition of assets solely between or among Metromedia
Fiber Network and its Wholly Owned Restricted Subsidiaries.
    
 
   
    Upon any consolidation or merger or any transfer of all or substantially all
of the assets of Metromedia Fiber Network in accordance with the foregoing, the
successor corporation formed by such consolidation or into which Metromedia
Fiber Network is merged or to which such transfer is made shall succeed to and
(except in the case of a lease) be substituted for, and may exercise every right
and power of, Metromedia Fiber Network under the indenture with the same effect
as if such successor corporation had been named therein as Metromedia Fiber
Network, and (except in the case of a lease) Metromedia Fiber Network shall be
released from the obligations under the notes and the indenture except with
respect to any obligations that arise from, or are related to, such transaction.
    
 
   
    For purposes of the foregoing, the transfer (by assignment, sale or
otherwise) of all or substantially all of the properties and assets of one or
more Subsidiaries, Metromedia Fiber Network's interest in which constitutes all
or substantially all of the properties and assets of Metromedia Fiber Network,
shall be deemed to be the transfer of all or substantially all of the properties
and assets of Metromedia Fiber Network.
    
 
    TRANSACTIONS WITH AFFILIATES
 
   
    Metromedia Fiber Network will not, and will not permit any of its Restricted
Subsidiaries to, make any payment to, or sell, lease, transfer or otherwise
dispose of any of its properties or assets to, or purchase any property or
assets from, or enter into or make or amend any transaction, contract,
agreement, understanding, loan, advance or guarantee with, or for the benefit
of, any Affiliate (each of the foregoing, an "Affiliate Transaction"), unless:
    
 
   
    (i) such Affiliate Transaction is on terms that are not materially less
favorable to Metromedia Fiber Network or the relevant Restricted Subsidiary than
those that would have been obtained in a comparable transaction by Metromedia
Fiber Network or such Restricted Subsidiary with an unrelated Person, and
    
 
   
    (ii) with respect to any Affiliate transaction or series of related
Affiliate transactions (A) involving aggregate consideration in excess of $5.0
million, Metromedia Fiber Network delivers to the trustee a resolution of the
Board of Directors set forth in an Officers' Certificate that such Affiliate
transaction is approved by a majority of the disinterested members of the Board
of Directors and that, except with respect to matters governed by the Management
Agreement, certifying that such Affiliate transaction complies with clause (i)
above and is in the best interests of Metromedia Fiber Network or such
Restricted Subsidiary and (B) if involving aggregate consideration in excess of
$15.0 million, a favorable written opinion as to the fairness to Metromedia
Fiber Network of such Affiliate transaction from a financial point of view is
also obtained by Metromedia Fiber Network from an accounting, appraisal or
investment banking firm of national standing.
    
 
   
    Notwithstanding the foregoing, the following items shall not be deemed to be
Affiliate transactions:
    
 
    (i) (a) the entering into, maintaining or performance of any employment
contract, collective bargaining agreement, benefit plan, program or arrangement,
related trust agreement or any other similar arrangement for or with any
employee, officer or director heretofore or hereafter entered into in the
ordinary course of business, including vacation, health, insurance, deferred
compensation, retirement, savings or other similar plans,
 
                                       93
<PAGE>
    (b) the payment of compensation, performance of indemnification or
       contribution obligations, or an issuance, grant or award of stock,
       options, or other equity-related interests or other securities, to
       employees, officers or directors in the ordinary course of business,
 
    (c) any transaction with an officer or director in the ordinary course of
       business not involving more than $100,000 in any one case, or
 
    (d) Management Advances and payments in respect thereof,
 
   
    (ii) transactions between or among Metromedia Fiber Network and/or its
Restricted Subsidiaries,
    
 
    (iii) payment of reasonable directors fees,
 
   
    (iv) any sale or other issuance of Equity Interests (other than Disqualified
Stock) of Metromedia Fiber Network,
    
 
   
    (v) Affiliate transactions in effect or approved by the Board of Directors
on the Issue Date, including any amendments thereto (PROVIDED that the terms of
such amendments are not materially less favorable to Metromedia Fiber Network
than the terms of such agreement prior to such amendment),
    
 
   
    (vi) transactions with respect to capacity between Metromedia Fiber Network
or any Restricted Subsidiary and any Unrestricted Subsidiary or another
Affiliate and joint sales and marketing pursuant to an agreement or agreements
between Metromedia Fiber Network or any Restricted Subsidiary and any
Unrestricted Subsidiary or another Affiliate (PROVIDED that in the case of this
clause (vi), such agreements are on terms that are no less favorable to
Metromedia Fiber Network or the relevant Restricted Subsidiary than those that
could have been obtained at the time of such transaction in an arm's-length
transaction with an unrelated third party or, in the case of a transaction with
an Unrestricted Subsidiary, ION or another Affiliate, are either (x) entered
into in connection with a transaction involving the selection by a customer of
cable system capacity entered into in the ordinary course of business or (y)
involve the provision by Metromedia Fiber Network or a Restricted Subsidiary to
an Unrestricted Subsidiary, ION or another Affiliate of sales and marketing
services, operations, administration and maintenance services or development
services for which Metromedia Fiber Network or such Restricted Subsidiary
receives a fair rate of return (as determined by the Board of Directors and set
forth in an Officers' Certificate delivered to the trustee) above its expenses
of providing such services), and
    
 
    (vii) Restricted Payments that are permitted by the covenant described above
under the caption "--Restricted Payments."
 
BUSINESS ACTIVITIES
 
   
    Metromedia Fiber Network will not, and will not permit any of its Restricted
Subsidiaries to, engage, to more than a de minimus extent, in any business other
than a Telecommunications Business.
    
 
PAYMENTS FOR CONSENT
 
   
    Metromedia Fiber Network and each of its Restricted Subsidiaries will not
directly or indirectly, pay or cause to be paid any consideration, whether by
way of interest, fee or otherwise, to any Holder of any notes for or as an
inducement to any consent, waiver or amendment of any of the terms or provisions
of the indenture or the notes unless such consideration is offered to be paid or
is paid to all Holders of the notes that consent, waive or agree to amend such
terms or provisions of the indenture or the notes in the time frame set forth in
the solicitation documents relating to such consent, waiver or agreement.
    
 
                                       94
<PAGE>
    REPORTS
 
   
    Whether or not required by the rules and regulations of the Securities and
Exchange Commission, so long as any notes are outstanding, Metromedia Fiber
Network will furnish to the Trustee and the Holders of the notes:
    
 
   
    (i) all quarterly and annual financial information that would be required to
be contained in a filing with the Securities and Exchange Commission on Forms
10-Q and 10-K if Metromedia Fiber Network were required to file such Forms,
including a "Management's Discussion and Analysis of Financial Condition and
Results of Operations" that describes the financial condition and results of
operations of Metromedia Fiber Network and its consolidated Subsidiaries and,
with respect to the annual information only, a report thereon by Metromedia
Fiber Network's certified independent accountants, and
    
 
   
    (ii) all current reports that would be required to be filed with the
Securities and Exchange Commission on Form 8-K if Metromedia Fiber Network were
required to file such reports, in each case within the time periods specified in
the Securities and Exchange Commission's rules and regulations.
    
 
   
    In addition, following the consummation of the exchange offer, whether or
not required by the rules and regulations of the Securities and Exchange
Commission, Metromedia Fiber Network will file a copy of all such information
and reports with the Securities and Exchange Commission for public availability
within the time periods specified in the Commission's rules and regulations
(unless the Securities and Exchange Commission will not accept such a filing)
and make such information available to securities analysts and prospective
investors upon request.
    
 
EVENTS OF DEFAULT AND REMEDIES
 
   
    The indenture will provide that each of the following will constitute an
Event of Default:
    
 
   
    (i) default for 30 days in the payment when due of interest on the notes;
    
 
   
    (ii) default in the payment when due of the principal of, or premium, if
any, on, the notes;
    
 
   
    (iii) failure by Metromedia Fiber Network or any of its Restricted
Subsidiaries to comply with the provisions described above under the captions
"--Change of Control," or "--Asset Sales";
    
 
   
    (iv) failure by Metromedia Fiber Network or any of its Restricted
Subsidiaries for 60 days after notice to comply with any of its other agreements
in the indenture or the notes;
    
 
   
    (v) default under any mortgage, indenture or instrument under which there
may be issued or by which there may be secured or evidenced any Indebtedness for
money borrowed by Metromedia Fiber Network or any of its Restricted Subsidiaries
(or the payment of which is guaranteed by Metromedia Fiber Network or any of its
Restricted Subsidiaries) whether such Indebtedness or Guarantee now exists, or
is created after the Issue Date, which default results in the acceleration of
such Indebtedness prior to its express maturity and, in each case, the amount of
any such Indebtedness, together with the amount of any other such Indebtedness
or the maturity of which has been so accelerated, aggregates $15 million or
more;
    
 
   
    (vi) failure by Metromedia Fiber Network or any of its Restricted
Subsidiaries to pay final judgments not subject to appeal aggregating in excess
of $15 million (net of applicable insurance coverage which is acknowledged in
writing by the insurer), which judgments are not paid, vacated, discharged or
stayed for a period of 60 days; and
    
 
    (vii) certain events of bankruptcy or insolvency with respect to the Company
or any of its Restricted Subsidiaries.
 
                                       95
<PAGE>
   
    If any Event of Default occurs and is continuing, the trustee or the holders
of at least 25% in principal amount of the then outstanding notes may declare
all the notes to be due and payable immediately. Notwithstanding the foregoing,
in the case of an Event of Default arising from certain events of bankruptcy or
insolvency, with respect to Metromedia Fiber Network, any Restricted Subsidiary
that is a Significant Subsidiary or any group of Restricted Subsidiaries that,
taken together, would constitute a Significant Subsidiary, all outstanding notes
will become due and payable without further action or notice. Holders of the
notes may not enforce the indenture or the notes except as provided in the
indenture. Subject to certain limitations, holders of a majority in principal
amount of the then outstanding notes may direct the trustee in its exercise of
any trust or power. The trustee may withhold from holders of the notes notice of
any continuing Default or Event of Default (except a Default or Event of Default
relating to the payment of principal of, premium, if any, or interest on, the
notes) if it determines that withholding notice is in their interest.
    
 
   
    The holders of a majority (or super majority of at least 66 2/3% in the case
of any covenant requiring 66 2/3% to amend) in aggregate principal amount of the
then outstanding notes by notice to the trustee may on behalf of the holders of
all of the notes waive any existing Default or Event of Default and its
consequences under the indenture, except a continuing Default or Event of
Default in the payment of principal of, premium, if any, or interest on the
notes.
    
 
   
    Metromedia Fiber Network will be required to deliver to the trustee annually
a statement regarding compliance with the indenture, and Metromedia Fiber
Network will be required upon becoming aware of any Default or Event of Default
to deliver to the Trustee a statement specifying such Default or Event of
Default.
    
 
NO PERSONAL LIABILITY OF DIRECTORS, OFFICERS, EMPLOYEES, INCORPORATORS OR
  SHAREHOLDERS
 
   
    No director, officer, employee, incorporator or shareholder of Metromedia
Fiber Network, as such, will have any liability for any obligations of
Metromedia Fiber Network with respect to the notes or the indenture, or for any
claim based on, or in respect or by reason of, such obligations or their
creation. Each holder of notes by accepting a note will waive and release any
and all such liability. Such waiver and release are part of the consideration
for issuance of the notes. Such waiver may not be effective to waive liabilities
under federal securities laws and it is the view of the Securities and Exchange
Commission that such a waiver is against public policy.
    
 
LEGAL DEFEASANCE AND COVENANT DEFEASANCE
 
   
    The indenture will be discharged and cancelled upon the delivery by
Metromedia Fiber Network to the trustee for cancellation of all the notes or
upon irrevocable deposit with the trustee, within not more than one year prior
to the final stated maturity of the notes, or when the notes are to be called
for redemption within one year under arrangements satisfactory to the trustee,
of funds sufficient for the payment or redemption of all the notes.
    
 
   
    In addition, the indenture will provide that Metromedia Fiber Network may,
at its option and at any time, elect to have all of its obligations discharged
with respect to the outstanding notes ("legal defeasance"), except for:
    
 
   
    (i) the rights of holders of outstanding notes to receive payments in
respect of the principal of, premium, if any, and interest on such notes when
such payments are due from the trust referred to below;
    
 
   
    (ii) Metromedia Fiber Network's obligations with respect to the notes
concerning issuing temporary notes, registration of notes, mutilated, destroyed,
lost or stolen notes and the maintenance of an office or agency for payment and
money for security payments held in trust;
    
 
                                       96
<PAGE>
   
    (iii) the rights, powers, trusts, duties and immunities of the trustee, and
Metromedia Fiber Network's obligations in connection therewith; and
    
 
   
    (iv) the legal defeasance provisions of the indenture.
    
 
   
    In addition, Metromedia Fiber Network may, at its option and at any time,
elect to have its obligations released with respect to certain covenants that
are contained in the indenture ("covenant defeasance") and, thereafter, any
omission to comply with such obligations will not constitute a Default or Event
of Default. In the event covenant defeasance occurs, certain events (but not
including non-payment, bankruptcy, receivership, rehabilitation or insolvency
events) described under "--Events of Default and Remedies" will no longer
constitute an Event of Default.
    
 
   
    In order to exercise either legal defeasance or covenant defeasance:
    
 
   
    (i) Metromedia Fiber Network must irrevocably deposit, or cause to be
deposited, with the trustee, in trust, for the benefit of the holders of the
notes, cash in U.S. dollars, non-callable Government Securities, or a
combination thereof, in such amounts as will be sufficient, in the opinion of a
nationally recognized firm of independent public accountants, to pay the
principal of, premium, if any, and interest on the outstanding notes on the
stated maturity thereof or on the applicable redemption date, as the case may
be, and Metromedia Fiber Network must specify whether the notes are being
defeased to maturity or to a particular redemption date;
    
 
   
    (ii) in the case of legal defeasance, Metromedia Fiber Network must deliver
to the trustee an opinion of counsel in the United States reasonably acceptable
to the Trustee confirming that, since the Issue Date, Metromedia Fiber Network
has received from, or there has been published by, the Internal Revenue Service
a ruling, or there has been a change in the applicable United States federal
income tax law, in either case to the effect that, and based thereon such
opinion of counsel shall confirm that, the holders of the outstanding notes will
not recognize income, gain or loss for United States federal income tax purposes
as a result of such legal defeasance, and will be subject to United States
federal income tax on the same amounts, in the same manner and at the same times
as would have been the case if such legal defeasance had not occurred;
    
 
   
    (iii) in the case of covenant defeasance, Metromedia Fiber Network must
deliver to the trustee an opinion of counsel in the United States reasonably
acceptable to the trustee confirming that the Holders of the outstanding notes
will not recognize income, gain or loss for United States federal income tax
purposes as a result of such covenant defeasance, and such holders will be
subject to United States federal income tax on the same amounts, in the same
manner and at the same times as would have been the case if such covenant
defeasance had not occurred;
    
 
    (iv) no Default or Event of Default shall have occurred and be continuing on
the date of such deposit (other than a Default or Event of Default resulting
from the borrowing of funds to be applied to such deposit) or insofar as Events
of Default from bankruptcy or insolvency events are concerned, at any time in
the period ending on the 91st day after the date of deposit;
 
   
    (v) such legal defeasance or covenant defeasance will not result in a breach
or violation of, or constitute a default under, any material agreement or
instrument (other than the indenture) to which Metromedia Fiber Network or any
of its Restricted Subsidiaries is a party or by which Metromedia Fiber Network
or any of its Restricted Subsidiaries is bound;
    
 
   
    (vi) Metromedia Fiber Network must deliver to the trustee an Officers'
Certificate stating that the deposit was not made by Metromedia Fiber Network
with the intent of preferring the holders of the notes over other creditors of
Metromedia Fiber Network, or with the intent of defeating, hindering, delaying
or defrauding creditors of Metromedia Fiber Network or others; and
    
 
   
    (vii) Metromedia Fiber Network must deliver to the trustee an Officers'
Certificate and an opinion of counsel in the United States reasonably acceptable
to the trustee, each stating that the conditions
    
 
                                       97
<PAGE>
   
precedent provided for or relating to legal defeasance or covenant defeasance,
as applicable, in the case of the Officers' Certificate, in clauses (i) through
(vi) and, in the case of the opinion of counsel, in clauses (i) (with respect to
the validity and perfection of the security interest) and clauses (ii) and (iii)
of this paragraph, have been complied with.
    
 
TRANSFER AND EXCHANGE
 
   
    A holder may transfer or exchange notes in accordance with the procedures
set forth in the indenture. The registrar and the trustee may require a holder,
among other things, to furnish appropriate endorsements and transfer documents,
and Metromedia Fiber Network may require a holder to pay any taxes and fees
required by law or permitted by the indenture.
    
 
   
    Metromedia Fiber Network will not be required to transfer or exchange any
note selected for redemption. Also, Metromedia Fiber Network will not be
required to transfer or exchange any note for a period of 15 days before:
    
 
   
    (i) a selection of notes to be redeemed,
    
 
    (ii) an interest payment date, or
 
    (iii) the mailing of notice of a Change of Control Offer or Asset Sale
Offer.
 
   
    The registered holder of a note will be treated as the owner of it for all
purposes under the indenture.
    
 
AMENDMENT, SUPPLEMENT AND WAIVER
 
   
    The indenture contains provisions permitting Metromedia Fiber Network and
the trustee to enter into a supplemental indenture for certain limited purposes
without the consent of the holders. With the consent of the holders of not less
than a majority in aggregate principal amount of the notes at the time
outstanding, Metromedia Fiber Network and the trustee are permitted to amend or
supplement the indenture or any supplemental indenture or modify the rights of
the holders; PROVIDED that no such modification may, without the consent of
holders of at least 66 2/3% in aggregate principal amount of notes at the time
outstanding, modify the provisions (including the defined terms used therein) of
the covenant "Repurchase at the Option of the Holders--Change of Control" in a
manner adverse to the holders or, except with respect to the Lien on the
security account, release or modify a Lien granted to the holders of the notes;
and PROVIDED that no such modification may, without the consent of each holder
affected thereby:
    
 
   
    (i) change the Stated Maturity on any note, or reduce the principal amount
thereof or the rate (or extend the time for payment) of interest thereon or any
premium payable upon the redemption at the option of Metromedia Fiber Network
thereof, or change the place of payment where, or the coin or currency in which,
any note or any premium or the interest thereon is payable, or impair the right
to institute suit for the enforcement of any such payment on or after the Stated
Maturity thereof (or, in the case of redemption at the option of Metromedia
Fiber Network, on or after the Redemption Date) or reduce the Change of Control
Payment or the Asset Sale Offer Price after the corresponding Asset Sale or
Change of Control has occurred, or
    
 
   
    (ii) alter the provisions (including the defined terms used therein)
regarding the right of Metromedia Fiber Network to redeem the notes as a right,
or at the option, of Metromedia Fiber Network in a manner adverse to the
holders, or
    
 
   
    (iii) reduce the percentage in principal amount of the outstanding notes,
the consent of whose holders is required for any such amendment, supplemental
indenture or waiver provided for in the indenture, or
    
 
                                       98
<PAGE>
   
    (iv) modify any of the waiver provisions, except to increase any required
percentage or to provide that certain other provisions of the indenture cannot
be modified or waived without the consent of the holder of each outstanding note
affected thereby, or
    
 
   
    (v) cause the notes to become subordinate in right of payment to any other
Indebtedness, or
    
 
   
    (vi) release any funds from the security account in any manner inconsistent
with the provisions of the security agreement as in effect on the Issue Date or
modify any provision of the security agreement in a manner adverse to the
holders of the notes.
    
 
   
    Notwithstanding the foregoing, without the consent of any holder of notes,
Metromedia Fiber Network and the trustee may amend or supplement the indenture
or the notes:
    
 
    (i) to cure any ambiguity, defect or inconsistency,
 
   
    (ii) to provide for uncertificated notes in addition to or in place of
certificated notes,
    
 
   
    (iii) to provide for the assumption of Metromedia Fiber Network's
obligations to holders of notes in the case of a merger or consolidation or sale
of all or substantially all of Metromedia Fiber Network's assets in accordance
with the terms of the indenture,
    
 
   
    (iv) to make any change that would provide any additional rights or benefits
to the holders of notes or that does not adversely affect the legal rights under
the indenture of any such holder, or
    
 
   
    (v) to comply with the requirements of the Securities and Exchange
Commission in order to effect or maintain the qualification of the indenture
under the Trust Indenture Act.
    
 
CONCERNING THE TRUSTEE
 
   
    The indenture contains certain limitations on the rights of the trustee,
should it become a creditor of Metromedia Fiber Network, to obtain payment of
claims in certain cases, or to realize on certain property received in respect
of any such claim as security or otherwise. The trustee will be permitted to
engage in other transactions; however, if it acquires any conflicting interest,
it must eliminate such conflict within 90 days, apply to the Securities and
Exchange Commission for permission to continue, or resign.
    
 
   
    The holders of a majority in principal amount of the then outstanding notes
will have the right to direct the time, method and place of conducting any
proceeding for exercising any remedy available to the trustee, subject to
certain exceptions. In case an Event of Default shall occur (which shall not be
cured) the trustee will be required, in the exercise of its power, to use the
degree of care of a prudent person in the conduct of their own affairs. Subject
to such provisions, the trustee will be under no obligation to exercise any of
its rights or powers under the indenture at the request of any holder of notes,
unless such holder shall have offered to the trustee security and indemnity
satisfactory to it against any loss, liability or expense.
    
 
GOVERNING LAW
 
   
    The indenture and the notes are governed by and construed in accordance with
the laws of the State of New York.
    
 
   
    Metromedia Fiber Network will submit to the jurisdiction of the U.S. federal
and New York state courts located in the Borough of Manhattan, City and State of
New York for purposes of all legal actions and proceedings instituted in
connection with the notes and the indenture.
    
 
CERTAIN DEFINITIONS
 
   
    We have provided below certain defined terms used in the indenture. We urge
you to read the Indenture for a full disclosure of all such terms, as well as
any other capitalized terms used in this Prospectus for which we have provided
no definition.
    
 
                                       99
<PAGE>
    "ACQUIRED DEBT" or "ACQUIRED PREFERRED STOCK" means, with respect to any
specified Person, Indebtedness or Preferred Stock of any other Person existing
at the time such other Person is merged with or into or became a Subsidiary of
such specified Person (including by Designation or Revocation) provided such
Indebtedness or Preferred Stock is not incurred in connection with, or in
contemplation of, such other Person merging with or into or becoming a
Subsidiary of such specified Person.
 
    "AFFILIATE" of any specified Person means any other Person directly or
indirectly controlling, controlled by or under direct or indirect common control
with such specified Person. For purposes of this definition, "control"
(including, with correlative meanings, the terms "controlling," "controlled by"
and "under common control with") as used with respect to any Person, shall mean
the possession, directly or indirectly, of the power to direct or cause the
direction of the management or policies of such Person, whether through the
ownership of voting securities, by agreement or otherwise; PROVIDED that
beneficial ownership of 10% or more of the Voting Stock of a Person shall be
deemed to be control.
 
    "ASSET SALE" means:
 
   
    (i) the sale, lease, transfer, conveyance or other disposition of any assets
        or rights (including, without limitation, by way of a sale and
        leaseback) other than sales of inventory in the ordinary course of
        business and other than any sale, lease, transfer, conveyance or other
        disposition in the ordinary course of business of capacity on any fiber
        optic or cable system owned, controlled or operated by Metromedia Fiber
        Network or any Restricted Subsidiary or of telecommunications capacity,
        transmission rights, conduit or rights-of-way acquired by Metromedia
        Fiber Network or any Restricted Subsidiary for use in a
        Telecommunications Business of Metromedia Fiber Network or any
        Restricted Subsidiary (PROVIDED that the sale, lease, transfer,
        conveyance or other disposition of all or substantially all of the
        assets of Metromedia Fiber Network and its Restricted Subsidiaries taken
        as a whole will be governed by the provisions of the indenture described
        above under the caption "--Repurchase at the Option of Holders--Change
        of Control" and/or the provisions described above under the caption
        "--Certain Covenants--Merger, Consolidation or Sale of Assets" and not
        by the provisions of the Asset Sale covenant), and
    
 
   
    (ii) the issue or sale by Metromedia Fiber Network or any of its Restricted
         Subsidiaries of Equity Interests of any Subsidiary.
    
 
   
    Notwithstanding the foregoing, the following items shall not be deemed to be
Asset Sales: (i) a transfer of assets by Metromedia Fiber Network to a
Consolidated Subsidiary or by a Subsidiary to Metromedia Fiber Network or to a
Consolidated Subsidiary, (ii) an issuance of Equity Interests by a Subsidiary to
Metromedia Fiber Network or to a Consolidated Subsidiary, (iii) a Restricted
Payment that is permitted by the covenant described above under the caption
"--Certain Covenants--Restricted Payments," (iv) Permitted Investments made in
accordance with clause (a) or (c) of the definition thereof, (v) a disposition
of obsolete or worn out equipment or equipment that is no longer useful in the
conduct of a Telecommunications Business of Metromedia Fiber Network and its
Restricted Subsidiaries and that is disposed of in the ordinary course of
business, (vi) the surrender or waiver by Metromedia Fiber Network or any of its
Restricted Subsidiaries of contract rights or the settlement, release or
surrender of contract, tort or other claims of any kind by Metromedia Fiber
Network or any of its Restricted Subsidiaries or the grant by Metromedia Fiber
Network or any of its Restricted Subsidiaries of a Lien not prohibited by the
indenture, (vii) the sale of Cash Equivalents in the ordinary course of
business; and (viii) sales, transfers, assignments and other dispositions of
assets (or related assets in related transactions) in the ordinary course of
business with an aggregate fair market value of less than $1.0 million.
    
 
   
    "BOARD OF DIRECTORS" means the board of directors or other governing body of
Metromedia Fiber Network or, if Metromedia Fiber Network is owned or managed by
a single entity, the board of
    
 
                                      100
<PAGE>
directors or other governing body of such entity, or, in either case, any
committee thereof duly authorized to act on behalf of such board or governing
body.
 
    "BOARD RESOLUTION" means a duly authorized resolution of the Board of
Directors.
 
   
    "CAPITAL CONTRIBUTION" means any contribution to the equity of Metromedia
Fiber Network from a direct or indirect parent of Metromedia Fiber Network for
which no consideration other than the issuance of common stock with no
redemption rights and no special preferences, privileges or voting rights is
given.
    
 
    "CAPITAL LEASE OBLIGATION" means, at the time any determination thereof is
to be made, the amount of the liability in respect of a capital lease that would
at such time be required to be capitalized on a balance sheet in accordance with
GAAP.
 
    "CAPITAL STOCK" means (i) in the case of a corporation, corporate stock,
(ii) in the case of an association or business entity, any and all shares,
interests, participations, rights or other equivalents (however designated) of
corporate stock, (iii) in the case of a partnership or limited liability
company, partnership or membership interests (whether general or limited) and
(iv) any other interest or participation that confers on a Person the right to
receive a share of the profits and losses of, or distributions of assets of, the
issuing Person.
 
    "CASH EQUIVALENTS" means (i) United States dollars, (ii) securities issued
or directly and fully guaranteed or insured by the United States government or
any agency or instrumentality thereof (provided that the full faith and credit
of the United States is pledged in support thereof) having maturities of not
more than six months from the date of acquisition, (iii) certificates of deposit
and eurodollar time deposits with maturities of six months or less from the date
of acquisition, bankers' acceptances with maturities not exceeding six months
and overnight bank deposits, in each case with any domestic commercial bank
having capital and surplus in excess of $500 million and a Thompson Bank Watch
Rating of "B" or better, (iv) repurchase obligations with a term of not more
than seven days for underlying securities of the types described in clause (ii)
above entered into with any financial institution meeting the qualifications
specified in clause (iii) above, (v) commercial paper having the highest rating
obtainable from Moody's Investors Service, Inc. or Standard & Poor's Ratings
Group and in each case maturing within six months after the date of acquisition
and (vi) money market funds at least 95% of the assets of which constitute Cash
Equivalents of the kinds described in clauses (i)-(v) of this definition,
PROVIDED that with respect to any Foreign Subsidiary, Cash Equivalents shall
also mean those investments that are comparable to clauses (iii) through (vi)
above in such Foreign Subsidiary's country of organization or country where it
conducts business operations.
 
    "CHANGE OF CONTROL" means the occurrence of any of the following:
 
   
    (i) any "person" or "group" (as such terms are used in Section 13(d)(3) of
        the Securities Exchange Act of 1934), other than a Permitted Holder, is
        or becomes the beneficial owner, directly or indirectly, of 35% or more
        of the Voting Stock (measured by voting power rather than number of
        shares) of Metromedia Fiber Network and the Permitted Holders own, in
        the aggregate, a lesser percentage of the total Voting Stock (measured
        by voting power rather than by number of shares) of Metromedia Fiber
        Network than such person and do not have the right or ability by voting
        power, contract or otherwise to elect or designate for election a
        majority of the board of directors of Metromedia Fiber Network (for the
        purposes of this clause, such other person shall be deemed to
        "beneficially own" any Voting Stock of a specified corporation held by a
        parent corporation if such other person beneficially owns, directly or
        indirectly, more than 35% of the Voting Stock (measured by voting power
        rather than by number of shares) of such parent corporation and the
        Permitted Holders beneficially own, directly or indirectly, in the
        aggregate a lesser percentage of Voting Stock (measured by voting power
        rather than by number of shares) of such parent corporation and do not
        have
    
 
                                      101
<PAGE>
        the right or ability by voting power, contract or otherwise to elect or
        designate for election a majority of the board of directors of such
        parent corporation),
 
   
    (ii) during any period of two consecutive years, Continuing Directors cease
         for any reason to constitute a majority of the Board of Directors of
         Metromedia Fiber Network,
    
 
   
   (iii) Metromedia Fiber Network consolidates or merges with or into any other
         Person, other than a consolidation or merger (a) of Metromedia Fiber
         Network into a Wholly Owned Restricted Subsidiary of Metromedia Fiber
         Network or (b) pursuant to a transaction in which the outstanding
         Voting Stock of Metromedia Fiber Network is changed into or exchanged
         for cash, securities or other property with the effect that the
         beneficial owners of the outstanding Voting Stock of Metromedia Fiber
         Network immediately prior to such transaction, beneficially own,
         directly or indirectly, at least a majority of the Voting Stock
         (measured by voting power rather than number of shares) of the
         surviving corporation immediately following such transaction, or
    
 
   
    (iv) the sale, transfer, conveyance or other disposition (other than by way
         of merger or consolidation) in one or a series of related transactions,
         of all or substantially all of the assets of Metromedia Fiber Network
         and its Restricted Subsidiaries taken as a whole to any person other
         than a Wholly Owned Restricted Subsidiary of Metromedia Fiber Network
         or a Permitted Holder or a person more than 50% of the Voting Stock
         (measured by voting power rather than by number of shares) of which is
         owned, directly or indirectly, following such transaction or
         transactions by the Permitted Holders; PROVIDED, HOWEVER, that sales,
         transfers, conveyances or other dispositions in the ordinary course of
         business of capacity on cable systems owned, controlled or operated by
         Metromedia Fiber Network or any Restricted Subsidiary or fiber optic or
         of telecommunications capacity or transmission rights, rights-of-way or
         conduit acquired by Metromedia Fiber Network or any Restricted
         Subsidiary for use in the Telecommunications Business of Metromedia
         Fiber Network or a Restricted Subsidiary, including, without
         limitation, for sale, lease, transfer, conveyance or other disposition
         to any customer of Metromedia Fiber Network or any Restricted
         Subsidiary shall not be deemed a disposition of assets for purposes of
         this clause (iv).
    
 
   
    The definition of a Change of Control includes a phrase relating to the
sale, lease, transfer, conveyance or other disposition of "all or substantially
all" of the assets of Metromedia Fiber Network and its Restricted Subsidiaries
taken as a whole. The indenture is governed by New York law, and there is no
clearly established meaning under New York law of the phrase "substantially all"
of the assets of a corporation. Accordingly, the ability of a Holder of notes to
require Metromedia Fiber Network to purchase such notes as a result of a sale,
lease, transfer, conveyance or other disposition of less than all of the assets
of Metromedia Fiber Network and its Restricted Subsidiaries taken as a whole to
another Person or group may be uncertain.
    
 
   
    "CONSOLIDATED CAPITAL RATIO" means, with respect to Metromedia Fiber Network
as of any date, the ratio of (i) the aggregate consolidated amount of
Indebtedness of Metromedia Fiber Network and its Restricted Subsidiaries then
outstanding to (ii) the Consolidated Net Worth of Metromedia Fiber Network and
its Consolidated Subsidiaries as of such date.
    
 
   
    "CONSOLIDATED CASH FLOW" means, with respect to Metromedia Fiber Network for
any period, the Consolidated Net Income of Metromedia Fiber Network and its
Consolidated Subsidiaries for such period
    
 
   
    plus (A) to the extent that any of the following items were deducted in
computing such Consolidated Net Income, but without duplication, (i) provision
for taxes based on income or profits of Metromedia Fiber Network and its
Consolidated Subsidiaries for such period, plus (ii) consolidated interest
expense of Metromedia Fiber Network and its Consolidated Subsidiaries for such
period,
    
 
                                      102
<PAGE>
   
whether paid or accrued and whether or not capitalized (including, without
limitation, amortization of debt issuance costs and original issue discount,
non-cash interest payments, the interest component of any deferred payment
obligations, the interest component of all payments associated with Capital
Lease Obligations, commissions, discounts and other fees and charges incurred in
respect of letter of credit or bankers' acceptance financings, and net payments
(if any) pursuant to Hedging Obligations) plus (iii) depreciation, amortization
(including amortization of goodwill and other intangibles and the amount of
capacity available for sale (other than for backhaul capacity) charged to cost
of sales) but excluding amortization of prepaid cash expenses that were paid in
a prior period) and other non-cash expenses (excluding any such non-cash expense
to the extent that it represents an accrual of or reserve for cash expenses in
any future period or amortization of a prepaid cash expense that was paid in a
prior period) of Metromedia Fiber Network and its Consolidated Subsidiaries for
such period,
    
 
    minus (B) non-cash items increasing such Consolidated Net Income for such
period (other than items that were accrued in the ordinary course of business)
in each case, on a consolidated basis and determined in accordance with GAAP.
 
   
    Notwithstanding the foregoing, the provision for taxes on the income or
profits of, and the depreciation and amortization and other non-cash expenses
of, a Restricted Subsidiary of Metromedia Fiber Network shall be added to
Consolidated Net Income to compute Consolidated Cash Flow of Metromedia Fiber
Network only to the extent that a corresponding amount would be permitted at the
date of determination to be dividended to Metromedia Fiber Network by such
Restricted Subsidiary without prior governmental approval (that has not been
obtained) and without direct or indirect restriction pursuant to the terms of
its charter and all agreements, instruments, judgments, decrees, orders,
statutes, rules and governmental regulations applicable to that Restricted
Subsidiary or its shareholders.
    
 
   
    "CONSOLIDATED LEVERAGE RATIO" means, with respect to Metromedia Fiber
Network, as of any date, the ratio of (i) the aggregate consolidated amount of
Indebtedness of Metromedia Fiber Network and its Restricted Subsidiaries then
outstanding to (ii) the annualized Consolidated Cash Flow of Metromedia Fiber
Network and its Consolidated Subsidiaries for the most recently ended fiscal
quarter.
    
 
   
    "CONSOLIDATED NET INCOME" means, with respect to Metromedia Fiber Network
for any period, the aggregate of the Net Income of Metromedia Fiber Network and
its Consolidated Subsidiaries for such period, on a consolidated basis,
determined in accordance with GAAP; PROVIDED that:
    
 
   
    (i) the Net Income (but not loss) of any Person that is accounted for by the
equity method of accounting shall be included only to the extent of the amount
of dividends or distributions paid in cash to Metromedia Fiber Network or a
Consolidated Subsidiary thereof by such Person but not in excess of the
Company's Equity Interests in such Person,
    
 
   
    (ii) the Net Income of any Restricted Subsidiary shall be excluded to the
extent that the declaration or payment of dividends or similar distributions by
that Restricted Subsidiary of that Net Income is not at the date of
determination permitted without any prior governmental approval (that has not
been obtained) or, directly or indirectly, by operation of the terms of its
charter or any agreement, instrument, judgment, decree, order, statute, rule or
governmental regulation applicable to that Restricted Subsidiary or its
shareholders, except that Metromedia Fiber Network equity in the net income of
any such Restricted Subsidiary for such period may be included in such
Consolidated Net Income up to the aggregate amount of cash that could have been
distributed by such Restricted Subsidiary during such period to Metromedia Fiber
Network as a dividend,
    
 
    (iii) the Net Income of any Person acquired in a pooling of interests
transaction for any period prior to the date of such acquisition shall be
excluded,
 
                                      103
<PAGE>
   
    (iv) the equity of Metromedia Fiber Network or any Restricted Subsidiary in
the net income (if positive) of any Unrestricted Subsidiary shall be included in
such Consolidated Net Income up to the aggregate amount of cash actually
distributed by such Unrestricted Subsidiary during such period to Metromedia
Fiber Network or a Consolidated Subsidiary as a dividend or other distribution
(but not in excess of the amount of the Net Income of such Unrestricted
Subsidiary for such period) and
    
 
    (v) the cumulative effect of a change in accounting principles shall be
excluded.
 
   
    "CONSOLIDATED NET WORTH" means, with respect to Metromedia Fiber Network as
of any date, the sum of (i) the consolidated equity of the common shareholders
of the Company and its Consolidated Subsidiaries that are Consolidated
Subsidiaries as of such date plus (ii) the respective amounts reported on
Metromedia Fiber Network balance sheet as of such date with respect to any
series of Preferred Stock (other than Disqualified Stock) that by its terms is
not entitled to the payment of dividends unless such dividends may be declared
and paid only out of net earnings in respect of the year of such declaration and
payment, but only to the extent of any cash received by Metromedia Fiber Network
upon issuance of such Preferred Stock, less (x) all write-ups (other than
write-ups resulting from foreign currency translations and write-ups of tangible
assets of a going concern business made within 12 months after the acquisition
of such business) subsequent to the Closing Date in the book value of any asset
owned by Metromedia Fiber Network or a Restricted Subsidiary that is a
Consolidated Subsidiary of Metromedia Fiber Network, (y) all outstanding net
Investments as of such date in unconsolidated Restricted Subsidiaries and in
Persons that are not Restricted Subsidiaries (except, in each such case,
Permitted Investments) and (z) all unamortized debt discount and expense and
unamortized deferred charges as of such date, all of the foregoing determined in
accordance with GAAP.
    
 
    "CONSOLIDATED SUBSIDIARY" means, for any Person, each Restricted Subsidiary
of such Person (whether now existing or hereafter created or acquired) the
financial statements of which are consolidated for financial statement reporting
purposes with the financial statements of such Person in accordance with GAAP.
 
   
    "CONTINUING DIRECTORS" means individuals who at the beginning of the period
of determination constituted the Board of Directors of Metromedia Fiber Network,
together with any new directors whose election by such Board of Directors or
whose nomination for election by the shareholders of Metromedia Fiber Network
was approved by a vote of a majority of the directors of Metromedia Fiber
Network then still in office who were either directors at the beginning of such
period or whose election or nomination for election was previously so approved
or is the designee of any one of the Permitted Holders or any combination
thereof or was nominated or elected by any such Permitted Holder(s) or any of
their designees.
    
 
   
    "CREDIT AGREEMENT" means one or more credit agreements, loan agreements or
similar facilities, secured or unsecured, entered into from time to time by
Metromedia Fiber Network and its Restricted Subsidiaries, and including any
related notes, Guarantees, collateral documents, instruments and agreements
executed in connection therewith, as the same may be amended, supplemented,
modified, restated or replaced from time to time.
    
 
    "CURRENCY AGREEMENT" means, with respect to any Person, any foreign exchange
contract, currency swap agreement or other similar agreement as to which such
Person is a party or beneficiary.
 
    "DEFAULT" means any event that is, or with the passage of time or the giving
of notice or both would be, an Event of Default.
 
    "DISQUALIFIED STOCK" means any Capital Stock that, by its terms (or by the
terms of any security into which it is convertible, or for which it is
exchangeable, in each case at the option of the holder thereof) or upon the
happening of any event, matures or is mandatorily redeemable, pursuant to a
sinking fund obligation or otherwise, or redeemable at the option of the Holder
thereof, in whole or in
 
                                      104
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part, on or prior to the date that is 91 days after the date on which the Notes
mature; PROVIDED, HOWEVER, that any Capital Stock that would constitute
Disqualified Stock solely because the holders thereof have the right to require
Metromedia Fiber Network to repurchase such Capital Stock upon the occurrence of
a Change of Control or an Asset Sale shall not constitute Disqualified Stock if
the terms of such Capital Stock provide that Metromedia Fiber Network may not
repurchase or redeem any such Capital Stock pursuant to such provisions unless
such repurchase or redemption complies with the covenant described above under
the caption "--Certain Covenants Restricted Payments."
    
 
    "EQUITY INTERESTS" means Capital Stock and all warrants, options or other
rights to acquire Capital Stock (but excluding any debt security that is
convertible into, or exchangeable for, Capital Stock).
 
   
    "EXISTING ASSETS" means property, plant and equipment and other tangible
business assets existing as of the Closing Date used in a Telecommunications
Business of Metromedia Fiber Network, but does not include cash or Cash
Equivalents existing on the Closing Date, and the proceeds from the sale,
disposition or other transfer of any Existing Assets outside the ordinary course
of business.
    
 
   
    "EXISTING INDEBTEDNESS" means Indebtedness of Metromedia Fiber Network and
its Restricted Subsidiaries in existence on the Closing Date, until such amounts
are repaid.
    
 
   
    "FOREIGN SUBSIDIARY" means any Restricted Subsidiary of Metromedia Fiber
Network which (i) is not organized under the laws of the United States, any
state thereof or the District of Columbia, and (ii) conducts substantially all
of its business operations outside the United States of America.
    
 
   
    "FOREIGN SUBSIDIARY CREDIT AGREEMENT" means one or more credit agreements,
loan agreements or similar facilities, secured or unsecured, entered into from
time to time by one or more of Metromedia Fiber Network's Foreign Subsidiaries,
and including any related notes, Guarantees, collateral documents, instruments
and agreements executed in connection therewith, as the same may be amended,
supplemented, modified, restated or replaced from time to time.
    
 
    "GAAP" means generally accepted accounting principles set forth in the
opinions and pronouncements of the Accounting Principles Board of the American
Institute of Certified Public Accountants and statements and pronouncements of
the Financial Accounting Standards Board or in such other statements by such
other entity as have been approved by a significant segment of the accounting
profession, which are in effect on the Closing Date.
 
   
    "GERMAN JOINT VENTURE" means the Person(s) formed or organized to engineer,
develop and construct the German network.
    
 
    "GOVERNMENT SECURITIES" means securities that are (a) direct obligations (or
certificates representing an ownership interest in such obligations) of the
United States of America (including any agency or instrumentally thereof) of the
payment of which the full faith and credit of the United States of America is
pledged, (b) obligations of a Person controlled or supervised by and acting as
an agency or instrumentality of the United States of America the payment of
which is unconditionally guaranteed as a full faith and credit obligation by the
United States of America or (c) obligations of a Person the payment of which is
unconditionally guaranteed as a full faith and credit obligation by the United
States of America.
 
    "GUARANTEE" means any obligation, contingent or otherwise, of any Person
directly or indirectly guaranteeing any Indebtedness of any other Person (i) to
purchase or pay (or advance or supply funds for the purchase or payment of) such
Indebtedness of such other Person (whether arising by virtue of partnership
arrangements, or by agreement to keep-well, to purchase assets, goods,
securities or services, to take-or-pay, or to maintain financial statement
conditions or otherwise) or (ii) entered into for purposes of assuring in any
other manner the obligee of such Indebtedness of the payment thereof or to
protect such obligee against loss in respect thereof (in whole or in part)
PROVIDED, HOWEVER, that
 
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the term "Guarantee" shall not include endorsements for collection or deposit in
the ordinary course of business. The term "Guarantee" used as a verb has a
corresponding meaning.
 
    "HEDGING OBLIGATIONS" means, with respect to any Person, the obligations of
such Person under any Interest Rate Agreement or Currency Agreement.
 
    "INDEBTEDNESS" means, with respect to any Person, any indebtedness of such
Person, whether or not contingent, in respect of borrowed money or evidenced by
bonds, notes, debentures or similar instruments or letters of credit (or
reimbursement agreements in respect thereof) or banker's acceptances or
representing Capital Lease Obligations or the balance of the deferred and unpaid
purchase price of any property or representing any Hedging Obligations, except
any such balance that constitutes an accrued expense or trade payable, if and to
the extent any of the foregoing (other than letters of credit (or reimbursement
agreements in respect thereof), banker's acceptances and Hedging Obligations)
would appear as a liability upon a balance sheet of such Person prepared in
accordance with GAAP, as well as all Indebtedness of others secured by a Lien on
any asset of such Person (whether or not such Indebtedness is assumed by such
Person), Disqualified Stock of such Person and Preferred Stock of such Person's
Restricted Subsidiaries and, to the extent not otherwise included, the Guarantee
by such Person of any Indebtedness of any other Person. The amount of any
Indebtedness outstanding as of any date shall be (i) the accreted value thereof,
in the case of any Indebtedness issued with original issue discount, but the
accretion of original issue discount in accordance with the original terms of
Indebtedness issued with an original issue discount will not be deemed to be an
incurrence, and (ii) the principal amount thereof, together with any interest
thereon that is more than 30 days past due, in the case of any other
Indebtedness.
 
    "INTEREST RATE AGREEMENT" means, with respect to any Person, any interest
rate protection agreement, interest rate future agreement, interest rate option
agreement, interest rate swap agreement, interest rate cap agreement, interest
rate collar agreement, interest rate hedge agreement or other similar agreement
or arrangement to which such Person is a party or beneficiary.
 
   
    "INVESTMENTS" means, with respect to any Person, all investments by such
Person in other Persons (including Affiliates) in the forms of direct or
indirect loans (including Guarantees of Indebtedness or other obligations),
advances or capital contributions (excluding commission, travel and similar
advances to directors, officers and employees made in the ordinary course of
business), purchases or other acquisitions for consideration of Indebtedness,
Equity Interests or other securities, together with all items that are or would
be classified as investments on a balance sheet prepared in accordance with
GAAP. If Metromedia Fiber Network or any of its Restricted Subsidiaries sells or
otherwise disposes of any Equity Interests of any direct or indirect Subsidiary
such that, after giving effect to any such sale or disposition, such Person is
no longer a Subsidiary of Metromedia Fiber Network or such Restricted
Subsidiary, Metromedia Fiber Network shall be deemed to have made an Investment
on the date of any such sale or disposition equal to the fair market value of
the Equity Interests of such Subsidiary not sold or disposed of in an amount
determined as provided in the final paragraph of the covenant described above
under the caption "--Certain Covenants and Restricted Payments."
    
 
    "ION" means International Optical Network, L.L.C., a Delaware limited
liability company.
 
   
    "ISSUE DATE" means the date of first issuance of the initial notes under the
indenture.
    
 
    "LIEN" means, with respect to any asset, any mortgage, lien, pledge, charge,
security interest or encumbrance of any kind in respect of such asset, whether
or not filed, recorded or otherwise perfected under applicable law (including
any conditional sale or other title retention agreement, any lease in the nature
thereof, any option or other agreement to sell or give a security interest in,
and any filing of or agreement to give any financing statement under the Uniform
Commercial Code (or equivalent statutes) of any jurisdiction).
 
                                      106
<PAGE>
    "MANAGEMENT ADVANCES" means loans or advances made to directors, officers or
employees of the Company or any Restricted Subsidiary (i) in respect of travel,
entertainment or moving-related expenses incurred in the ordinary course of
business, (ii) in respect of moving-related expenses incurred in connection with
any closing or consolidation of any facility, or (iii) otherwise in the ordinary
course of business not exceeding $3.0 million in the aggregate at any time
outstanding.
 
    "MANAGEMENT AGREEMENT" means the Metromedia Management Agreement as the same
may be amended, supplemented, modified, restated or replaced from time to time
with the approval of a majority of the disinterested members of the Board of
Directors.
 
   
    "NET CASH PROCEEDS" means the aggregate amount of cash or Cash Equivalents
received by the Company in the case of a sale, or Capital Contribution in
respect, of Capital Stock and by Metromedia Fiber Network and its Restricted
Subsidiaries in respect of an Asset Sale plus, in the case of an issuance of
Capital Stock upon any exercise, exchange or conversion of securities (including
options, warrants, rights and convertible or exchangeable debt) of Metromedia
Fiber Network that were issued for cash on or after the Closing Date, the amount
of cash originally received by Metromedia Fiber Network upon the issuance of
such securities (including options, warrants, rights and convertible or
exchangeable debt) less, in each case, the sum of all payments, fees,
commissions and reasonable and customary expenses (including, without
limitation, the fees and expenses of legal counsel and investment banking fees
and expenses) incurred in connection with such Asset Sale or sale of Capital
Stock, and, in the case of an Asset Sale only, less the amount (estimated
reasonably and in good faith by Metromedia Fiber Network) of income, franchise,
sales and other applicable federal, state, provincial, foreign and local taxes
required to be paid or accrued as a liability by Metromedia Fiber Network or any
of its respective Restricted Subsidiaries in connection with such Asset Sale in
the taxable year that such sale is consummated or in the immediately succeeding
taxable year, the computation of which shall take into account the reduction in
tax liability resulting from any available operating losses and net operating
loss carryovers, tax credits and tax credit carryforwards, and similar tax
attributes.
    
 
    "NET INCOME" means, with respect to any Person, the net income (loss) of
such Person, determined in accordance with GAAP and before any reduction in
respect of preferred stock dividends, excluding, however, (i) any gain (but not
loss), together with any related provision for taxes on such gain (but not
loss), realized in connection with (a) any Asset Sale or (b) the disposition of
any securities by such Person or any of its Restricted Subsidiaries or the
extinguishment of any Indebtedness of such Person or any of its Restricted
Subsidiaries and (ii) any extraordinary gain or loss, together with any related
provision for taxes on such extraordinary gain or loss.
 
   
    "NON-RECOURSE DEBT" means Indebtedness (i) as to which neither Metromedia
Fiber Network nor any Restricted Subsidiary (a) provides any Guarantee or credit
support of any kind (including any undertaking, guarantee, indemnity, agreement
or instrument that would constitute Indebtedness) or (b) is directly or
indirectly liable (as a guarantor or otherwise) and (ii) no default with respect
to which (including any rights that the holders thereof may have to take
enforcement action against an Unrestricted Subsidiary) would permit (upon
notice, lapse of time or both) any holder of any other Indebtedness of
Metromedia Fiber Network or any Restricted Subsidiary to declare a default under
such other Indebtedness or cause the payment thereof to be accelerated or
payable prior to its Stated Maturity.
    
 
   
    "OFFICER" means the President, the Chief Executive Officer, any Executive
Vice President, and the Chief Financial Officer of Metromedia Fiber Network.
    
 
    "OFFICERS' CERTIFICATE" means a certificate signed by two Officers.
 
   
    "PARI PASSU INDEBTEDNESS" means Indebtedness of Metromedia Fiber Network
ranking PARI PASSU in right of payment with the notes.
    
 
                                      107
<PAGE>
   
    "PERMITTED HOLDER" means Metromedia Company, its general partners and their
respective Related Persons and Persons that would constitute a Class B Permitted
Holder as defined in Metromedia Fiber Network's Amended and Restated Certificate
of Incorporation.
    
 
   
    "PERMITTED INVESTMENTS" means (a) any Investment in Metromedia Fiber Network
or in a Consolidated Subsidiary of Metromedia Fiber Network that is engaged
entirely or substantially entirely in a Telecommunications Business; (b) any
Investment in Cash Equivalents; and (c) any Investment by Metromedia Fiber
Network or any of its Restricted Subsidiaries in a Person, if as a result of
such Investment (i) such Person becomes a Consolidated Subsidiary of Metromedia
Fiber Network that is engaged entirely or substantially entirely in a
Telecommunications Business or (ii) such Person is merged, consolidated or
amalgamated with or into, or transfers or conveys substantially all of its
assets to, or is liquidated into, Metromedia Fiber Network or a Consolidated
Subsidiary of Metromedia Fiber Network that is engaged entirely or substantially
entirely in a Telecommunications Business.
    
 
   
    "PERMITTED LIENS" means (i) Liens to secure Indebtedness permitted by
clauses (e) (f), (g) and (h) of the second paragraph of the covenant described
above under the caption "--Incurrence of Indebtedness and Issuance of Preferred
Stock", PROVIDED that with respect to Liens to secure Indebtedness permitted by
clause (f) thereof or any Permitted Refinancing Indebtedness of such
Indebtedness, such Lien must cover only the assets acquired with such
Indebtedness; (ii) Liens in favor of Metromedia Fiber Network or any Restricted
Subsidiary; (iii) Liens on property of a Person existing at the time such Person
is merged with or into or consolidated with Metromedia Fiber Network or any of
its Restricted Subsidiaries, PROVIDED that such Liens were in existence prior to
the contemplation of such merger or consolidation and do not extend to any
assets other than those of the Person merged into or consolidated with
Metromedia Fiber Network or such Restricted Subsidiary; (iv) Liens on property
existing at the time of acquisition thereof by Metromedia Fiber Network or any
of its Restricted Subsidiaries, PROVIDED that such Liens were in existence prior
to the contemplation of such acquisition; (v) Liens to secure the performance of
statutory obligations, surety or appeal bonds, performance bonds or other
obligations of a like nature incurred in the ordinary course of business; (vi)
Liens existing on the Closing Date; (vii) Liens for taxes, assessments or
governmental charges or claims that are not yet delinquent or that are being
contested in good faith by appropriate proceedings promptly instituted and
diligently concluded, PROVIDED that any reserve or other appropriate provision
as shall be required in conformity with GAAP shall have been made therefor;
(viii) zoning restrictions, rights-of-way, easements and similar charges or
encumbrances incurred in the ordinary course which in the aggregate do not
detract from the value of the property thereof, and (ix) Liens incurred in the
ordinary course of business of Metromedia Fiber Network or any of its Restricted
Subsidiaries with respect to obligations that do not exceed $5.0 million at any
one time outstanding and that (a) are not incurred in connection with the
borrowing of money or the obtaining of advances or credit (other than trade
credit in the ordinary course of business) and (b) do not in the aggregate
materially detract from the value of the property or materially impair the use
thereof in the operation of business by Metromedia Fiber Network or such
Restricted Subsidiary.
    
 
   
    "PERMITTED REFINANCING INDEBTEDNESS" means any Indebtedness of Metromedia
Fiber Network or any of its Restricted Subsidiaries issued in exchange for, or
the net proceeds of which are used to extend, refinance, renew, replace, defease
or refund other Indebtedness of Metromedia Fiber Network or any of its
Restricted Subsidiaries (other than intercompany Indebtedness); PROVIDED that:
(i) the principal amount (or accreted value, if applicable) of such Permitted
Refinancing Indebtedness does not exceed the principal amount of (or accreted
value, if applicable), plus accrued interest on, the Indebtedness so extended,
refinanced, renewed, replaced, defeased or refunded (plus the amount of any
premium required to be paid in connection with such refinancing pursuant to the
terms of such Indebtedness or otherwise reasonably determined by Metromedia
Fiber Network to be necessary and reasonable expenses incurred in connection
therewith); (ii) such Permitted Refinancing Indebtedness has a final maturity
date later than the final maturity date of, and has a Weighted Average Life to
Maturity equal
    
 
                                      108
<PAGE>
   
to or greater than the Weighted Average Life to Maturity of, the Indebtedness
being extended, refinanced, renewed, replaced, defeased or refunded; (iii) if
the Indebtedness being extended, refinanced, renewed, replaced, defeased or
refunded is subordinated in right of payment to the Notes, such Permitted
Refinancing Indebtedness has a final maturity date later than the final maturity
date of, and is expressly subordinated in right of payment to, the notes on
terms at least as favorable to the Holders of the notes as those contained in
the documentation governing the Indebtedness being extended, refinanced,
renewed, replaced, defeased or refunded; (iv) such Indebtedness is incurred
solely by Metromedia Fiber Network or the Restricted Subsidiary who is the
obligor on the Indebtedness being extended, refinanced, renewed, replaced,
defeased or refunded; and (v) such Indebtedness is secured only by the assets,
if any, that secured the Indebtedness being extended, refinanced, renewed,
replaced, defeased or refunded.
    
 
    "PERSON" means any individual, corporation, partnership, joint venture,
limited liability company, incorporated or unincorporated association,
joint-stock company, trust, unincorporated organization or government or other
agency or political subdivision thereof or other entity of any kind.
 
    "PREFERRED STOCK" means any Equity Interest of any class or classes of a
Person (however designated) which is preferred as to payments of dividends, or
as to distributions upon any liquidation or dissolution, over Equity Interests
of any other class of such Person.
 
   
    "PUBLIC EQUITY OFFERING" means an underwritten offering of common stock of
Metromedia Fiber Network for cash pursuant to an effective registration
statement under the Securities Act.
    
 
   
    "PURCHASE MONEY INDEBTEDNESS" means Indebtedness (including Acquired Debt,
in the case of leases, Capital Lease Obligations, mortgage financings and
purchase money obligations) incurred for the purpose of financing all or any
part of the cost of the engineering, construction, installation, acquisition,
lease (other than pursuant to a sale and leaseback of Existing Assets),
development or improvement of any Telecommunications Assets used by Metromedia
Fiber Network or any Restricted Subsidiary, in the case of Indebtedness incurred
by Metromedia Fiber Network, or any Foreign Subsidiary, in the case of
Indebtedness incurred by any Foreign Subsidiary, including any related notes,
Guarantees, collateral documents, instruments and agreements executed in
connection therewith, as the same may be amended, supplemented, modified or
restated from time to time.
    
 
    "RELATED PERSON" means any Person who controls, is controlled by or is under
common control with a Permitted Holder; PROVIDED, that for purposes of this
definition "control" means the beneficial ownership of more than 50% of the
total voting power of a Person normally entitled to vote in the election of
directors, managers or trustees, as applicable, of a Person.
 
    "RESTRICTED INVESTMENT" means any Investment other than a Permitted
Investment.
 
   
    "RESTRICTED SUBSIDIARY" of a Person means any Subsidiary of the referent
Person that is not an Unrestricted Subsidiary. Unless the context specifically
requires otherwise, Restricted Subsidiary means a direct or indirect Restricted
Subsidiary of Metromedia Fiber Network.
    
 
    "SIGNIFICANT SUBSIDIARY" means any Restricted Subsidiary that would be a
"significant subsidiary" as defined in Article 1, Rule 1-02 of Regulation S-X,
promulgated pursuant to the Securities Act, as such Regulation is in effect on
the date hereof.
 
    "STATED MATURITY" means, with respect to any installment of interest or
principal on any series of Indebtedness, the date on which such payment of
interest or principal was scheduled to be paid in the original documentation
governing such Indebtedness, and shall not include any contingent obligations to
repay, redeem or repurchase any such interest or principal prior to the date
originally scheduled for the payment thereof.
 
                                      109
<PAGE>
   
    "SUBORDINATED INDEBTEDNESS" means Indebtedness of Metromedia Fiber Network
that is subordinated in right of payment by its terms or the terms of any
document or instrument or instrument relating thereto to the notes, in any
respect.
    
 
    "SUBSIDIARY" means, with respect to any Person, (i) any corporation,
association or other business entity of which more than 50% of the total voting
power of shares of Capital Stock entitled (without regard to the occurrence of
any contingency) to vote in the election of directors, managers or trustees
thereof is at the time owned or controlled, directly or indirectly, by such
Person or one or more of the other Subsidiaries of that Person (or a combination
thereof) and (ii) any partnership (a) the sole general partner or the managing
general partner of which is such Person or a Subsidiary of such Person or (b)
the only general partners of which are such Person or of one or more
Subsidiaries of such Person (or any combination thereof).
 
    "TELECOMMUNICATIONS ASSETS" means all assets, rights (contractual or
otherwise) and properties, whether tangible or intangible, used or intended for
use in connection with a Telecommunications Business and the Equity Interests of
a Person engaged entirely or substantially entirely in a Telecommunications
Business.
 
   
    "TELECOMMUNICATIONS BUSINESS" means the business of (i) transmitting, or
providing services relating to the transmission of, voice, video or data through
owned or leased transmission facilities, (ii) constructing, creating, developing
or marketing communications related network equipment, software and other
devices for use in a telecommunications business or (iii) evaluating,
participating or pursuing any other activity or opportunity that is primarily
related to those identified in (i) or (ii) above; PROVIDED, THAT, the
determination of what constitutes a Telecommunications Business shall be made in
good faith by the Board of Directors of Metromedia Fiber Network.
    
 
   
    "UNRESTRICTED SUBSIDIARY" means (i) any Subsidiary of Metromedia Fiber
Network that is designated by the Board of Directors as an Unrestricted
Subsidiary pursuant to a Board Resolution; but only to the extent that such
Subsidiary at the time of such designation: (a) has no Indebtedness other than
Non-Recourse Debt; (b) is a Person with respect to which neither Metromedia
Fiber Network nor any of its Restricted Subsidiaries has any direct or indirect
obligation to maintain or preserve such Person's financial condition or to cause
such Person to achieve any specified levels of operating results; and (c) has
not Guaranteed or otherwise directly or indirectly provided credit support for
any Indebtedness of Metromedia Fiber Network or any of its Restricted
Subsidiaries. Any such designation by the Board of Directors shall be evidenced
by filing with the Trustee a certified copy of the Board Resolution giving
effect to such designation and an Officers' Certificate certifying that such
designation complied with the foregoing conditions and was permitted by the
covenant described above under the caption "--Certain Covenants and Restricted
Payments." The Board of Directors of Metromedia Fiber Network may at any time
designate any Unrestricted Subsidiary to be a Restricted Subsidiary; provided
that such designation shall be deemed to be an incurrence of Indebtedness by a
Restricted Subsidiary of Metromedia Fiber Network of any outstanding
Indebtedness of such Unrestricted Subsidiary and such designation shall only be
permitted if (i) such Indebtedness is permitted under the covenant described
under the caption "--Certain Covenants--Incurrence of Indebtedness and Issuance
of Preferred Stock," calculated on a pro forma basis as if such designation had
occurred at the beginning of the applicable reference period, and (ii) no
Default or Event of Default would be in existence following such designation.
    
 
    "VOTING STOCK" of any Person as of any date means the Capital Stock of such
Person that is at the time entitled to vote in the election of the Board of
Directors of such Person.
 
    "WEIGHTED AVERAGE LIFE TO MATURITY" means, when applied to any Indebtedness
at any date, the number of years obtained by dividing (i) the sum of the
products obtained by multiplying (a) the amount of each then remaining
installment, sinking fund, serial maturity or other required payments of
principal, including payment at final maturity, in respect thereof, by (b) the
number of years (calculated
 
                                      110
<PAGE>
to the nearest one-twelfth) that will elapse between such date and the making of
such payment, by (ii) the then outstanding principal amount of such
Indebtedness.
 
    "WHOLLY OWNED RESTRICTED SUBSIDIARY" of any Person means a Restricted
Subsidiary of such Person all of the outstanding Capital Stock or other
ownership interests of which (other than directors' qualifying shares) shall at
the time be owned by such Person or by one or more Wholly Owned Restricted
Subsidiaries of such Person and one or more Wholly Owned Restricted Subsidiaries
of such Person.
 
BOOK-ENTRY, DELIVERY AND FORM
 
   
    Except as described below, we will initially issue the exchange notes in the
form of one or more registered exchange notes in global form without coupons. We
will deposit each global note on the date of the closing of the Exchange Offer
with, or on behalf of, DTC in New York, New York, and register the exchange
notes in the name of DTC or its nominee, or will leave such notes in the custody
of the Trustee.
    
 
    DEPOSITORY PROCEDURES
 
    We are providing you with the following description of the operations and
procedures of DTC, Euroclear and Cedel solely as a matter of convenience. These
operations and procedures are solely within the control of the respective
settlement systems and are subject to change by them from time to time. We take
no responsibility for these operations and procedures and urge you to contact
the system or their participants directly to discuss these matters.
 
   
    DTC has advised us that it is a limited-purpose trust company created to
hold securities for its participating organizations (collectively, the "direct
participants") and to facilitate the clearance and settlement of transactions in
those securities between direct participants through electronic book-entry
changes in accounts of participants. The direct participants include securities
brokers and dealers (including the initial purchasers), banks, trust companies,
clearing corporations and certain other organizations, including Euroclear and
Cedel. Access to DTC's system is also available to other entities that clear
through or maintain a direct or indirect, custodial relationship with a direct
participant (collectively, the "indirect participants"). DTC may hold securities
beneficially owned by other persons only through the direct participants or
indirect participants and such other persons' ownership interest and transfer of
ownership interest will be recorded only on the records of the direct
participant and/or indirect participant, and not on the records maintained by
DTC.
    
 
   
    DTC has also advised us that, pursuant to DTC's procedures, (i) upon deposit
of the global notes, DTC will credit the accounts of the direct participants
with an interest in the global notes, and (ii) DTC will maintain records of the
ownership interests of such direct participants in the global notes and the
transfer of ownership interests by and between direct participants. DTC will not
maintain records of the ownership interests of, or the transfer of ownership
interests by and between, indirect participants or other owners of beneficial
interests in the global notes. direct participants and indirect participants
must maintain their own records of ownership interests of, and the transfer of
ownership interests by and between, indirect participants and other owners of
beneficial interests in the global notes.
    
 
   
    Investors in the global notes may hold their interests in such notes
directly through DTC if they are direct participants in DTC or indirectly
through organizations (including Euroclear and Cedel) that are direct
participants in DTC. Euroclear and Cedel will hold interests in the global notes
on behalf of their participants through customers' securities accounts in their
respective names on the books of their respective depositories, which are Morgan
Guaranty Trust Company of New York, Brussels office, as operator of Euroclear,
and Citibank, N.A., as operator of Cedel. All interests in a global note,
including those held through Euroclear or Cedel, may be subject to the
procedures and requirements
    
 
                                      111
<PAGE>
of DTC. Those interests held through Euroclear or Cedel may also be subject to
the procedures and requirements of such systems.
 
   
    The laws of some states require that certain persons may take physical
delivery in definitive, certificated form, of securities that they own. This may
limit or curtail the ability to transfer beneficial interests in a global note
to such persons. Because DTC can act only on behalf of direct participants,
which in turn act on behalf of indirect participants and others, the ability of
a person having a beneficial interest in a global note to pledge such interest
to persons or entities that are not direct participants in DTC, or to otherwise
take actions in respect of such interests, may be affected by the lack of
physical certificates evidencing such interests.
    
 
   
    EXCEPT AS DESCRIBED BELOW, OWNERS OF INTERESTS IN THE GLOBAL NOTES WILL NOT
HAVE NOTES REGISTERED IN THEIR NAMES, WILL NOT RECEIVE PHYSICAL DELIVERY OF
NOTES IN CERTIFICATED FORM AND WILL NOT BE CONSIDERED THE REGISTERED OWNERS OR
"HOLDERS" THEREOF UNDER THE INDENTURE FOR ANY PURPOSE.
    
 
   
    Payments with respect to the principal of, premium, if any, and interest on,
any exchange notes represented by a global note registered in the name of DTC or
its nominee on the applicable record date will be payable by the trustee to or
at the direction of DTC or its nominee in its capacity as the registered holder
of the global note representing such exchange notes under the indenture. Under
the terms of the indenture, we and the trustee will treat the persons in whose
names the notes are registered (including notes represented by global notes) as
the owners thereof for the purpose of receiving payments and for any and all
other purposes whatsoever. Payments in respect of the principal, premium,
liquidated damages, if any, and interest on global notes registered in the name
of DTC or its nominee will be payable by the trustee to DTC or its nominee as
the registered holder under the indenture. Consequently, none of us, the trustee
or any of our agents, or the trustee's agents has or will have any
responsibility or liability for (i) any aspect of DTC's records or any direct
participant's or indirect participant's records relating to or payments made on
account of beneficial ownership interests in the global notes or for
maintaining, supervising or reviewing any of DTC's records or any direct
participant's or indirect participant's records relating to the beneficial
ownership interests in any global note or (ii) any other matter relating to the
actions and practices of DTC or any of its direct participants or indirect
participants.
    
 
   
    DTC has advised us that its current practice, upon receipt of any payment in
respect of securities such as the notes (including principal and interest), is
to credit the accounts of the relevant participants with the payment on the
payment date, in amounts proportionate to their respective holdings in the
principal amount of beneficial interest in the relevant security as shown on the
records of DTC, unless DTC has reason to believe it will not receive payment on
such payment date. Payments by the direct participants and the indirect
participants to the beneficial owners of interests in the Global Note will be
governed by standing instructions and customary practice and will be the
responsibility of the direct participants or the indirect participants, as the
case may be, and will not be the responsibility of DTC, the Trustee or us.
    
 
   
    None of us or the trustee will be liable for any delay by DTC or any direct
participant or indirect participant in identifying the beneficial owners of the
related exchange notes and we and the trustee may conclusively rely on, and will
be protected in relying on, instructions from DTC for all purposes (including
with respect to the registration and delivery, and the respective principal
amounts, of the exchange notes).
    
 
   
    Except for trades involving only Euroclear and Cedel participants, interests
in the global notes are expected to be eligible to trade in DTC's Same-Day Funds
Settlement System and secondary market trading activity in such interests will,
therefore, settle in immediately available funds, subject in all cases to the
rules and procedures of DTC and its participants. Please refer to the section in
this Prospectus entitled "--Same Day Settlement and Payment."
    
 
                                      112
<PAGE>
   
    Transfers between participants in DTC will be effected in accordance with
DTC's procedures, and will be settled in same day funds, and transfers between
participants in Euroclear and Cedel will be effected in the ordinary way in
accordance with their respective rules and operating procedures.
    
 
   
    Cross-market transfers between the participants in DTC, on the one hand, and
Euroclear or Cedel participants, on the other hand, will be effected through DTC
in accordance with DTC's rules on behalf of Euroclear or Cedel, as the case may
be, by its respective depositary. However, such cross market transactions will
require delivery of instructions to Euroclear or Cedel, as the case may be, by
the counterparty in such system in accordance with the rules and procedures and
within the established deadlines (Brussels time) of such system. Euroclear or
Cedel, as the case may be, will, if the transaction meets its settlement
requirements, deliver instructions to its respective depositary to take action
to effect final settlement on its behalf by delivering or receiving interests in
the relevant global note in DTC and making or receiving payment in accordance
with normal procedures for same-day funds settlement applicable to DTC.
Euroclear participants and Cedel participants may not deliver instructions
directly to the depositories for Euroclear or Cedel.
    
 
   
    DTC has advised us that it will take any action permitted to be taken by a
holder of notes only at the direction of one or more participants to whose
account DTC has credited the interests in the global notes and only in respect
of such portion of the aggregate principal amount of the notes as to which such
participant or participants has or have given such direction. However, if there
is an Event of Default with respect to the notes, DTC reserves the right to
exchange the global notes for legended notes in certificated form, and to
distribute such notes to its participants.
    
 
   
    Although DTC, Euroclear and Cedel have agreed to the foregoing procedures to
facilitate transfers of interests in the Regulation S global notes and in the
global notes among participants in DTC, Euroclear and Cedel, they are under no
obligation to perform or to continue to perform such procedures, and such
procedures may be discontinued at any time. None of us, the trustee or any of
our or the trustee's respective agents will have any responsibility for the
performance by DTC, Euroclear or Cedel or their respective participants or
indirect participants of their respective obligations under the rules and
procedures governing their operations.
    
 
    EXCHANGE OF BOOK-ENTRY NOTES FOR CERTIFICATED NOTES
 
   
    A global note is exchangeable for definitive notes in registered
certificated form if:
    
 
   
    - DTC notifies us that it is unwilling or unable to continue as depository
      for the global notes and we fail to appoint a successor depository within
      90 days, or
    
 
    - DTC ceases to be a clearing agency registered under the Securities
      Exchange Act of 1934, or
 
   
    - we elect to cause the issuance of the certificated notes upon a notice to
      the trustee, or
    
 
   
    - a Default or Event of Default under the notes has occurred and is
      continuing, or
    
 
   
    - such a request is made but only upon prior written notice given to the
      trustee by or on behalf of DTC in accordance with the indenture.
    
 
   
    In all cases, certificated notes delivered in exchange for any global note
or beneficial interests in a global note will be registered in the names, and
issued in any approved denominations, requested by or on behalf of the
depositary (in accordance with its customary procedures).
    
 
    EXCHANGE OF CERTIFICATED NOTES FOR BOOK-ENTRY NOTES
 
   
    Notes issued in certificated form may not be exchanged for beneficial
interests in any global note unless the transferor first delivers to the trustee
a written certificate (in the form provided in the
    
 
                                      113
<PAGE>
   
indenture) to the effect that such transfer will comply with the appropriate
transfer restrictions applicable to such notes.
    
 
    SAME DAY SETTLEMENT AND PAYMENT
 
   
    The indenture requires that payments in respect of the notes represented by
the global notes (including principal, premium, if any, and interest) be made by
wire transfer of immediately available funds to the accounts specified by the
holder of the global notes. With respect to notes in certificated form, we will
make all payments of principal, premium, if any, and interest on the notes at
our office or agency maintained for such purpose within the City and State of
New York (initially the office of the paying agent maintained for such purpose)
or, at our option, by check mailed to the holders thereof at their respective
addresses set forth in the register of holders of notes. However, we are
required to make all payments of principal, premium, if any, and interest on
notes in certificated form the holders of which have given us wire transfer
instructions, by wire transfer of immediately available funds to the accounts
specified by the holders thereof. The notes represented by the global notes are
expected to be eligible to trade in DTC's Same-Day Funds Settlement System, and
any permitted secondary market trading activity in such notes will, therefore,
be required by DTC to be settled in immediately available funds. We expect that
secondary trading in any certificated notes will also be settled in immediately
available funds.
    
 
   
    Because of time zone differences, the securities account of a Euroclear or
Cedel participant purchasing an interest in a global note from a direct
participant or indirect participant in DTC will be credited, and any such
crediting will be reported to the relevant Euroclear or Cedel participant,
during the securities settlement processing day (which must be a business day
for Euroclear and Cedel) immediately following the settlement date of DTC. DTC
has advised us that cash received in Euroclear or Cedel as a result of sales of
interests in a global note by or through a Euroclear or Cedel participant to a
participant in DTC will be received with value on the settlement date of DTC but
will be available in the relevant Euroclear or Cedel cash account only as of the
business day for Euroclear or Cedel following DTC's settlement date.
    
 
                                      114
<PAGE>
   
                CERTAIN UNITED STATES FEDERAL TAX CONSIDERATIONS
    
 
   
    The following discussion is a summary of United States federal income and
estate tax considerations that may be relevant to the exchange of initial notes
for exchange notes pursuant to the exchange offer and to the purchase, ownership
and disposition of the exchange notes. This summary does not purport to be a
complete analysis of all of the potential United States federal income and
estate tax considerations relating to the purchase, ownership and disposition of
the exchange notes and generally does not address any other taxes that might be
applicable to a holder of the exchange notes. In the opinion of Paul, Weiss,
Rifkind, Wharton & Garrison, special United States tax counsel to Metromedia
Fiber Network, the discussion accurately reflects the material United States
federal income tax consequences to U.S. and non-U.S. Holders (as defined) of the
consummation of the exchange offer and the ownership and disposition of the
exchange notes. We cannot assure you that the United States Internal Revenue
Service will take a similar view of such consequences. Further, the discussion
does not address all aspects of taxation that may be relevant to particular
holders of initial notes or exchange notes in light of their individual
circumstances (including the effect of any foreign, state or local laws) or to
certain types of purchasers subject to special treatment under United States
federal income tax laws (including dealers in securities, insurance companies,
financial institutions, persons that hold the initial notes or exchange notes
that are a hedge or that are hedged against currency risks or that are part of a
straddle or conversion transaction or a constructive sale, persons whose
functional currency is not the U.S. dollar and tax-exempt entities). The
discussion below assumes that the initial notes or exchange notes are held as
capital assets within the meaning of section 1221 of the Internal Revenue Code
of 1986.
    
 
   
    The discussion of the United States federal income and estate tax
considerations below is based on currently existing provisions of the Code, the
applicable Treasury regulations promulgated and proposed thereunder, judicial
decisions, and administrative interpretations, all of which are subject to
change, possibly on a retroactive basis. Because individual circumstances may
differ, you are strongly urged to consult your tax advisor with respect to your
particular tax situation and the particular tax effects of any state, local,
non-United States or other tax laws and possible changes in the tax laws.
    
 
   
    As used in this section, the term "U.S. holder" means a beneficial owner of
an exchange note who or which is for United States federal income tax purposes
(i) a citizen or resident of the United States, (ii) a corporation, partnership
or other entity created or organized in or under the laws of the United States
or of any political subdivision thereof, (iii) an estate the income of which is
subject to United States federal income taxation regardless of its source or
(iv) a trust if a court within the United States is able to exercise primary
supervision over the administration of the trust and one or more United States
persons have the authority to control all substantial decisions of the trust.
The term also includes certain former citizens of the United States whose income
and gain on the exchange notes will be subject to United States taxation. As
used herein, the term "non-U.S. holder" means a beneficial owner of an exchange
note that is not a U.S. holder.
    
 
   
FEDERAL INCOME TAX CONSEQUENCES OF THE EXCHANGE OFFER
    
 
   
    The exchange of initial notes for exchange notes pursuant to the exchange
offer will not be treated as an "exchange" or otherwise as a taxable event to
holders. Consequently, (i) no gain or loss will be realized by a holder upon
receipt of an exchange note, (ii) the holding period of the exchange note will
include the holding period of the initial note exchanged therefor and (iii) the
adjusted tax basis of the exchange note will be the same as the adjusted tax
basis of the initial note exchanged therefor immediately before the exchange.
    
 
                                      115
<PAGE>
   
TAX CONSIDERATIONS FOR U.S. HOLDERS
    
 
    PAYMENTS OF INTEREST
 
   
    Interest on an exchange note generally will be taxable to a U.S. holder as
ordinary interest income at the time it accrues or is received in accordance
with the U.S. holder's method of accounting for United States federal income tax
purposes.
    
 
    MARKET DISCOUNT AND BOND PREMIUM
 
   
    If a U.S. holder purchases an exchange note for an amount that is less than
its principal amount, the difference generally will be treated as "market
discount". In such case, any partial principal payment on and gain realized on
the sale, exchange or retirement of the exchange note and unrealized
appreciation on certain nontaxable dispositions of the note will be treated as
ordinary income to the extent of the market discount that has not previously
been included in income and that is treated as having accrued on the exchange
note prior to such payment or disposition and the U.S. holder might be required
to defer all or a portion of the interest expense on any indebtedness incurred
or continued to purchase or carry such exchange note (in each case, unless the
U.S. holder has made an election to include such market discount in income as it
accrues). Unless the U.S. holder elects to treat market discount as accruing on
a constant yield method, market discount will be treated as accruing on a
straight-line basis over the remaining term of the exchange note. An election
made to include market discount in income as it accrues will apply to all debt
instruments acquired by the U.S. holder on or after the first day of the taxable
year to which such election applies and may be revoked only with the consent of
the Internal Revenue Service.
    
 
   
    If a U.S. holder purchases an exchange note for an amount in excess of all
amounts payable on the exchange note after the purchase date, other than
payments of stated interest, such excess will be treated as "bond premium". In
general, a U.S. holder may elect to amortize bond premium over the remaining
term of the exchange note on a constant yield method. The amount of bond premium
allocable to any accrual period is offset against the stated interest allocable
to such accrual period (and any excess may be deducted, subject to certain
limitations). An election to amortize bond premium applies to all taxable debt
instruments held at the beginning of the first taxable year to which such
election applies and thereafter acquired by the U.S. holder and may be revoked
only with the consent of the Internal Revenue Service.
    
 
   
    SALE, EXCHANGE OR RETIREMENT OF NOTES
    
 
   
    Upon the sale, exchange or retirement of a an exchange note, a U.S. holder
will recognize taxable gain or loss equal to the difference between the amount
of cash plus the fair market value of any property received (not including any
amount attributable to accrued but unpaid interest) and such holder's adjusted
tax basis in the exchange note. A U.S. holder's adjusted tax basis in an
exchange note will be its cost, increased by any accrued market discount
included in income and reduced by any amortized bond premium and any principal
payment on the exchange note received by such holder.
    
 
   
    Subject to the discussion of market discount above, gain or loss realized on
the sale, exchange or retirement of an exchange note by a U.S. holder generally
will be capital gain or loss if the exchange note is held as a capital asset by
the U.S. holder. Net capital gains of individuals are subject to tax at lower
rates than items of ordinary income. The deductibility of capital losses is
subject to limitations.
    
 
   
TAX CONSIDERATIONS FOR NON-U.S. HOLDERS
    
 
   
    Generally, payments of principal or interest on the exchange notes by
Metromedia Fiber Network or any paying agent to a beneficial owner of an
exchange note that is a non-U.S. holder will not be subject to U.S. federal
income or income withholding tax, provided that, in the case of interest, (i)
such
    
 
                                      116
<PAGE>
   
non-U.S. holder does not own, actually or constructively, 10% or more of the
combined voting power of all classes of stock of Metromedia Fiber Network
entitled to vote, (ii) such non-U.S. holder is not, for U.S. federal income tax
purposes, a controlled foreign corporation related to Metromedia Fiber Network
actually or constructively through stock ownership, (iii) such non-U.S. holder
is not a bank receiving interest described in section 881(c)(3)(A) of the Code
and (iv) either (a) the non-U.S. holder provides Metromedia Fiber Network or its
agent with an Internal Revenue Service Form W-8 (or a suitable substitute form)
signed under penalties of perjury that includes its name and address and
certifies as to its non-United States status in compliance with applicable law
and Treasury regulations or (b) a securities clearing organization, bank or
other financial institution that holds customers' securities in the ordinary
course of its trade or business holds the exchange note and provides a statement
to Metromedia Fiber Network or its agent signed under penalties of perjury in
which such organization, bank or financial institution certifies that such a
Form W-8 (or suitable substitute) has been received by it from the non-U.S.
holder or from another financial institution acting on behalf of the non-U.S.
holder and furnishes Metromedia Fiber Network or its agent with a copy thereof.
If these requirements cannot be met, a non-U.S. holder generally will be subject
to United States federal income withholding tax at a rate of 30% (or such lower
rate provided by an applicable treaty) with respect to payments of interest on
the exchange notes. The non-U.S. holder must inform Metromedia Fiber Network or
its agent or the financial institution to which the non-U.S. holder provided the
Form W-8 (or suitable substitute) within 30 days of any change in the
information provided in such form.
    
 
   
    Treasury regulations generally effective for payments made after December
31, 1999 (the "new regulations") provide alternative methods for satisfying the
certification requirements described in clause (iv) above. The new regulations
also will require, in the case of exchange notes held by a foreign partnership,
that (i) the certification be provided by the partners rather than by the
foreign partnership and (ii) the partnership provide certain information,
including a U.S. taxpayer identification number.
    
 
   
    A non-U.S. holder of an exchange note generally will not be subject to
United States federal income or income withholding tax on gain realized on the
sale, exchange, redemption, retirement or other disposition of such exchange
note, unless (i) such non-U.S. holder is an individual who is present in the
United States for 183 days or more in the taxable year of the disposition, and
certain other conditions are met or (ii) such gain is effectively connected with
the conduct by such non-U.S. holder of a trade or business in the United States.
    
 
   
    Notwithstanding the above, if a non-U.S. holder of an exchange note is
engaged in a trade or business in the United States and if interest on the
exchange note, or gain realized on the disposition of the exchange note, is
effectively connected with the conduct of such trade or business, the non-U.S.
holder generally will be subject to regular United States federal income tax on
such interest or gain in the same manner as if it were a U.S. holder, unless an
applicable treaty provides otherwise. In addition, if such non-U.S. holder is a
foreign corporation, it may be subject to a branch profits tax equal to 30% (or
such lower rate provided by an applicable treaty) of its effectively connected
earnings and profits for the taxable year, subject to certain adjustments. Even
though such effectively connected income is subject to income tax, and may be
subject to the branch profits tax, it generally is not subject to income
withholding if the non-U.S. holder delivers a properly executed Internal Revenue
Service Form 4224 (or other form applicable under the new regulations) to the
payor.
    
 
   
    An exchange note held by an individual non-U.S. holder who at the time of
death is not a United States citizen or resident of the United States (as
defined for United States federal estate tax purposes) will not be subject to
United States federal estate taxation as a result of such individual's death
unless (i) the individual owns, actually or constructively, 10% or more of the
combined voting power of all classes of stock of Metromedia Fiber Network
entitled to vote or (ii) the interest on the exchange note is effectively
connected with the conduct by such individual of a trade or business in the
United States.
    
 
                                      117
<PAGE>
TAX CONSIDERATIONS APPLICABLE TO BOTH U.S. HOLDERS AND NON-U.S. HOLDERS
 
    BACKUP WITHHOLDING AND INFORMATION REPORTING
 
   
    Under current United States federal income tax law, a 31% backup withholding
tax might apply to certain payments on, and the proceeds from a sale, exchange
or redemption of, the exchange notes, unless the holder of the exchange note (i)
is a corporation or comes within certain other exempt categories and, when
required, demonstrates that fact or (ii) provides a correct taxpayer
identification number, certifies as to its exemption from backup withholding and
otherwise complies with applicable requirements of the backup withholding rules.
    
 
   
    Backup withholding and information reporting generally will not apply to
payments made by Metromedia Fiber Network or a paying agent on an exchange note
to a non-U.S. holder if the certification described under "Tax Considerations
for Non-U.S. Holders" is duly provided or the non-U.S. holder otherwise
establishes an exemption and the payor does not have actual knowledge that the
holder is a U.S. holder or that the conditions of any other exemption are not,
in fact, satisfied. The payments of proceeds from the disposition of an exchange
note to or through a non-United States office of a "broker" (as defined in
applicable Treasury regulations) that is (i) a United States person, (ii) a
controlled foreign corporation for United States federal income tax purposes,
(iii) a foreign person, 50% or more of whose gross income from all sources for
certain periods is from activities effectively connected with the conduct of a
United States trade or business or (iv) after December 31, 1999, a foreign
partnership if either (a) more than 50% of the income or capital interest is
owned by U.S. holders or (b) such partnership has certain connections to the
United States, will be subject to information reporting requirements unless such
broker has documentary evidence in its files of the holder's non-U.S. holder
status and has no actual knowledge to the contrary or otherwise establishes an
exemption. Before January 1, 2000, backup withholding will not apply to any
payment of the proceeds from the sale of an exchange note made to or through a
foreign office of a broker. However, after December 31, 1999, backup withholding
might apply if the broker has actual knowledge that the payee is a U.S. holder.
Payments of the proceeds from the sale of an exchange note to or through the
United States office of a broker are subject to information reporting and
possible backup withholding unless the holder certifies, under penalties of
perjury, that it is not a U.S. holder and that certain other conditions are met
or otherwise establishes an exemption, provided that the broker does not have
actual knowledge that the holder is a U.S. holder or that the conditions of any
other exemption are not, in fact, satisfied.
    
 
   
    Holders of exchange notes should consult their tax advisors regarding the
application of backup withholding in their particular situations, the
availability of an exemption therefrom, and the procedure for obtaining such an
exemption, if available. Any amounts withheld from payment under the backup
withholding rules will be allowed as a credit against the holder's United States
federal income tax liability and may entitle the holder to a refund if the
required information is furnished to the Internal Revenue Service.
    
 
   
    THE FOREGOING DISCUSSION IS FOR GENERAL INFORMATION ONLY AND IS NOT TAX
ADVICE. ACCORDINGLY, YOU SHOULD CONSULT YOUR TAX ADVISOR AS TO THE PARTICULAR
TAX CONSEQUENCES TO YOU OF THE EXCHANGE OFFER AND OF PURCHASING, HOLDING AND
DISPOSING OF THE INITIAL NOTES OR THE EXCHANGE NOTES, INCLUDING THE
APPLICABILITY AND EFFECT OF ANY STATE, LOCAL OR NON-UNITED STATES TAX LAWS AND
ANY RECENT OR PROSPECTIVE CHANGES IN APPLICABLE TAX LAWS AND THE EFFECT OF THE
NEW REGULATIONS WITH RESPECT TO PAYMENTS MADE AFTER DECEMBER 31, 1999.
    
 
                                      118
<PAGE>
                              PLAN OF DISTRIBUTION
 
   
    Each broker-dealer that receives exchange notes for its own account pursuant
to the exchange offer in exchange for initial notes acquired by such
broker-dealer as a result of market making or other trading activities may be
deemed to be an "underwriter" within the meaning of the Securities Act and,
therefore, must deliver a prospectus meeting the requirements of the Securities
Act in connection with any resales, offers to resell or other transfers of the
exchange notes received by it in connection with the exchange offer.
Accordingly, each such broker-dealer must acknowledge that it will deliver a
prospectus meeting the requirements of the Securities Act in connection with any
resale of such exchange notes. The letter of transmittal states that by
acknowledging that it will deliver and by delivering a prospectus, a
broker-dealer will not be deemed to admit that it is an "underwriter" within the
meaning of the Securities Act. This Prospectus, as it may be amended or
supplemented from time to time, may be used by a broker-dealer in connection
with resales of exchange notes received in exchange for initial notes where such
initial notes were acquired as a result of market-making activities or other
trading activities. We have agreed that, starting on the consummation of the
exchange offer, and ending on the close of business 180 days after the
consummation of the exchange offer, we will make this Prospectus, as amended or
supplemented, available to any broker-dealer for use in connection with any such
resale.
    
 
   
    We will not receive any proceeds from any sale of exchange notes by
broker-dealers. Exchange notes received by broker-dealers for their own account
pursuant to the exchange offer may be sold from time to time in one or more
transactions in the over-the-counter market, in negotiated transactions, through
the writing of options on the exchange notes or a combination of such methods of
resale, at market prices prevailing at the time of resale, at prices related to
such prevailing market prices or negotiated prices. Any such resale may be made
directly to purchasers or to or through brokers or dealers who may receive
compensation in the form of commissions or concessions from any such
broker-dealer and/or the purchasers of any such exchange notes. Any
broker-dealer that resells exchange notes that were received by it for its own
account pursuant to the exchange offer and any broker or dealer that
participates in a distribution of such exchange notes may be deemed to be an
"underwriter" within the meaning of the Securities Act and any profit of any
such resale of exchange notes and any commissions or concessions received by any
such persons may be deemed to be underwriting compensation under the Securities
Act. The letter of transmittal states that by acknowledging that it will deliver
and by delivering a prospectus, a broker-dealer will not be deemed to admit that
it is an "underwriter" within the meaning of the Securities Act.
    
 
   
    For a period of 180 days after the consummation of the exchange offer, we
will promptly send additional copies of this Prospectus and any amendment or
supplement to this Prospectus to any broker-dealer that requests such documents
in the letter of transmittal. We have agreed to pay all expenses incident to the
exchange offer (including the expenses of one counsel for the holders of the
notes) other than commissions or concessions of any brokers or dealers and will
indemnify the holders of the notes (including any broker-dealers) against
certain liabilities, including liabilities under the Securities Act.
    
 
                                 LEGAL MATTERS
 
   
    Paul, Weiss, Rifkind, Wharton & Garrison, New York, New York, will pass upon
certain legal matters, including certain tax matters on our behalf, with respect
to the exchange notes.
    
 
                                      119
<PAGE>
                                    EXPERTS
 
    The consolidated financial statements of Metromedia Fiber Network, Inc. at
December 31, 1996 and December 31, 1997 and for the years then ended, appearing
in this Prospectus have been audited by Ernst & Young LLP, independent auditors,
as set forth in their report thereon appearing elsewhere in this Prospectus. Our
consolidated statements of operations, stockholders' deficiency and cash flows
for the twelve months ended December 31, 1995 have been audited by M.R. Weiser &
Co. LLP, Certified Public Accountants, as stated on their report. Their report
contains an explanatory paragraph regarding an uncertainty as to our ability to
continue as a going concern. Such financial statements are included in reliance
upon such reports given upon the authority of such firms as experts in
accounting and auditing.
 
                             AVAILABLE INFORMATION
 
   
    We have filed a registration statement on Form S-4 with the Securities and
Exchange Commission covering the exchange notes, and this Prospectus is part of
our registration statement. For further information on the Company and the
exchange notes, you should refer to our registration statement and its exhibits.
This Prospectus summarizes material provisions of contracts and other documents
that we refer you to. Since the Prospectus may not contain all the information
that you may find important, you should review the full text of these documents.
We have included copies of these documents as exhibits to our registration
statement.
    
 
   
    We are currently subject to the periodic reporting and other informational
requirements of the Securities Exchange Act of 1934. In addition, the indenture
requires that we file reports under the Securities Exchange Act of 1934 with the
Securities and Exchange Commission and provide those reports to the Trustee and
holders of the notes. You can inspect and copy at prescribed rates the reports
and other information that we file with the Securities and Exchange Commission
at the public reference facilities maintained by the Securities and Exchange
Commission at Room 1024, Judiciary Plaza, 450 Fifth Street, N.W., Washington,
D.C. 20549, and also at the regional offices of the Securities and Exchange
Commission located at 7 World Trade Center, Suite 1300, New York, New York 10048
and the Citicorp Center at 500 West Madison Street, Suite 1400, Chicago,
Illinois 60661-2511. You may obtain information on the operation of the public
reference facilities by calling the Securities and Exchange Commission at
1-800-SEC-0330. The Securities and Exchange Commission also maintains an
internet web site at http://www.sec.gov that contains reports, proxy and
information statements and other information. You can also obtain copies of such
materials from us upon request.
    
 
   
    We have agreed that, whether or not we are required to do so by the rules
and regulations of the Securities and Exchange Commission, for so long as any of
the exchange notes remain outstanding, we will furnish you as a holder of the
exchange notes and will, if permitted, file with the Securities and Exchange
Commission (i) all quarterly and annual financial information that would be
required to be contained in a filing with the Securities and Exchange Commission
on Forms 10-Q and 10-K if we were required to file such forms, including a
"Management's Discussion and Analysis of Financial Condition and Results of
Operations" and, with respect to the annual information only, a report thereon
by our certified independent accountants, and (ii) all reports that would be
required to be filed with the Securities and Exchange Commission on Form 8-K if
we were required to file such reports. In addition, for so long as any of the
exchange notes remain outstanding, we have agreed to make available to any
prospective purchaser of the exchange notes or beneficial owner of the notes in
connection with any sale thereof the information required by Rule 144 under the
Securities Act.
    
 
                                      120
<PAGE>
                      DOCUMENTS INCORPORATED BY REFERENCE
 
    The following documents and other materials, which we have filed with the
Securities and Exchange Commission, are incorporated herein and specifically
made a part of this Prospectus by this reference:
 
(1) Annual Report on Form 10-K for the fiscal year ended December 31, 1997;
 
(2) Quarterly Reports on Form 10-Q for the quarters ended September 30, 1997,
    March 31, 1998, June 30, 1998 and September 30, 1998;
 
(3) Proxy Statement for the Annual Meeting of Stockholders filed on May 18,
    1998; and
 
(4) Current Reports on Form 8-K filed on February 24, 1998, June 15, 1998, July
    16, 1998 and December 4, 1998.
 
   
    In addition, all documents that we file with the Securities and Exchange
Commission pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities
Exchange Act of 1934 after the date of this Prospectus will be deemed to be
incorporated by reference into this Prospectus and to be a part of this
Prospectus from the date of filing of such documents with the Securities and
Exchange Commission. Any statement contained in this Prospectus or in a document
incorporated or deemed to be incorporated by reference in this Prospectus will
be deemed to be modified or superseded for purposes of this Prospectus if a
statement contained in this Prospectus or in any other subsequently filed
document which also is or is deemed to be incorporated by reference herein
modifies or supersedes such statement. Any such statement so modified or
superseded will not be deemed, except as so modified or superseded, to
constitute a part of this Prospectus.
    
 
   
    Statements contained in this Prospectus or in any document incorporated by
reference in this Prospectus as to the contents of any contract or other
document referred to herein or therein are not necessarily complete. In each
instance, where applicable, we refer you to the copy of such contract or other
document filed as an exhibit to the documents incorporated by reference, each
such statement being qualified in all respects by such reference.
    
 
    This Prospectus incorporates documents by reference that are not presented
herein or delivered herewith. Copies of such documents, other than exhibits to
such documents that are not specifically incorporated by reference herein, are
available without charge to any person to whom this Prospectus is delivered,
upon written or oral request to: Metromedia Fiber Network, Inc., c/o Metromedia
Company, One Meadowlands Plaza, East Rutherford, NJ 07073; Attention: General
Counsel; tel: (201) 531-8000.
 
                                      121
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
                   INDEX TO CONSOLIDATED FINANCIAL STATEMENTS
 
<TABLE>
<S>                                                                                    <C>
Consolidated Statements of Operations for the Nine-Month Periods Ended September 30,
  1998 and 1997 (unaudited)..........................................................        F-2
Consolidated Balance Sheet as of September 30, 1998 (unaudited)......................        F-3
Consolidated Statements of Cash Flows for the Nine-Month Periods Ended September 30,
  1998 and 1997 (unaudited)..........................................................        F-4
Notes to Consolidated Financial Statements (unaudited)...............................        F-5
Reports of Independent Auditors......................................................       F-11
Consolidated Balance Sheets as of December 31, 1997 and 1996.........................       F-13
Consolidated Statements of Operations for the years ended December 31, 1997, 1996 and
  1995...............................................................................       F-14
Consolidated Statements of Cash Flows for the years ended December 31, 1997, 1996 and
  1995...............................................................................       F-15
Consolidated Statements of Changes in Stockholders' Equity (Deficiency) for the years
  ended December 31, 1997, 1996 and 1995.............................................       F-16
Notes to Consolidated Financial Statements...........................................       F-18
</TABLE>
 
                                      F-1
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
               CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED)
 
                      (IN 000'S, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                                                                              NINE MONTHS ENDED
                                                                                                SEPTEMBER 30,
                                                                                            ----------------------
<S>                                                                                         <C>         <C>
                                                                                               1998        1997
                                                                                            ----------  ----------
Revenue...................................................................................  $   20,840  $    1,745
Expenses:
  Cost of sales...........................................................................       9,499       2,647
  Selling, general and administrative.....................................................       9,811       3,722
  Consulting and employment incentives....................................................         248      19,124
  Settlement agreement....................................................................       3,400      --
  Depreciation and amortization...........................................................         738         567
                                                                                            ----------  ----------
 
Income (loss) from operations.............................................................      (2,856)    (24,315)
Interest income...........................................................................       5,028         491
Interest expense..........................................................................         (16)       (732)
Income (loss) from joint venture..........................................................        (264)     --
                                                                                            ----------  ----------
 
Income (loss) before income taxes.........................................................       1,892     (24,556)
Income taxes..............................................................................         825      --
                                                                                            ----------  ----------
Net income (loss).........................................................................  $    1,067  $  (24,556)
                                                                                            ----------  ----------
                                                                                            ----------  ----------
Net income (loss) per share, basic........................................................  $      .01  $     (.64)
                                                                                            ----------  ----------
                                                                                            ----------  ----------
Net income (loss) per share, diluted......................................................  $      .01         N/A
                                                                                            ----------  ----------
                                                                                            ----------  ----------
Weighted average number of shares outstanding, basic......................................      93,196      38,652
                                                                                            ----------  ----------
                                                                                            ----------  ----------
Weighted average number of shares outstanding, diluted....................................     108,604         N/A
                                                                                            ----------  ----------
                                                                                            ----------  ----------
</TABLE>
 
                             See accompanying notes
 
                                      F-2
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
                     CONSOLIDATED BALANCE SHEET (UNAUDITED)
 
                        (IN 000'S, EXCEPT SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                                                                                     SEPTEMBER 30,
                                                                                                         1998
                                                                                                     -------------
<S>                                                                                                  <C>
                                                                                                      (UNAUDITED)
                                                      ASSETS
Current assets:
  Cash and cash equivalents........................................................................   $    76,335
  Accounts receivable..............................................................................        17,902
  Prepaid expenses and other current assets........................................................         1,042
                                                                                                     -------------
    Total current assets...........................................................................        95,279
  Fiber optic transmission network and related equipment, net......................................       148,579
  Property and equipment, net......................................................................         1,732
  Investment in/advances to joint venture..........................................................         2,537
  Other assets.....................................................................................         7,300
                                                                                                     -------------
    Total assets...................................................................................   $   255,427
                                                                                                     -------------
                                                                                                     -------------
 
                                       LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Accounts payable.................................................................................   $     3,409
  Accrued expenses.................................................................................        39,119
  Current portion of deferred revenue..............................................................         6,409
  Current portion of capital lease obligations.....................................................            55
                                                                                                     -------------
    Total current liabilities......................................................................        48,992
Capital lease obligations..........................................................................        19,687
Deferred revenue...................................................................................        32,006
Commitments and contingencies (see notes)
Stockholders' equity:
  Class A common stock, $.01 par value; 180,000,000 shares authorized; 77,460,452 shares issued and
    outstanding....................................................................................           774
  Class B common stock, $.01 par value; 20,000,000 shares authorized; 16,884,636 shares issued and
    outstanding....................................................................................           169
  Additional paid-in capital.......................................................................       195,955
  Accumulated deficit..............................................................................       (42,156)
                                                                                                     -------------
    Total stockholders' equity.....................................................................       154,742
                                                                                                     -------------
    Total liabilities and stockholders' equity.....................................................   $   255,427
                                                                                                     -------------
                                                                                                     -------------
</TABLE>
 
                             See accompanying notes
 
                                      F-3
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
               CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)
 
                                   (IN 000'S)
 
<TABLE>
<CAPTION>
                                                                                              NINE MONTHS ENDED
                                                                                                SEPTEMBER 30,
                                                                                            ----------------------
                                                                                               1998        1997
                                                                                            ----------  ----------
<S>                                                                                         <C>         <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss).........................................................................  $    1,067  $  (24,556)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating
  activities:
    Depreciation and amortization.........................................................         738         567
    Options issued for settlement agreement...............................................       3,000          --
    Stocks, options and warrants issued for services......................................         248      19,344
    Reserve for accounts receivable.......................................................         156          --
    Loss from joint venture...............................................................         264          --
CHANGE IN OPERATING ASSETS AND LIABILITIES:
    Accounts receivable...................................................................     (17,221)       (162)
    Accounts payable and accrued expenses.................................................       3,442      (3,877)
    Deferred revenue......................................................................      26,920       8,225
    Other.................................................................................      (1,749)     (3,411)
                                                                                            ----------  ----------
  Net cash provided by (used in) operating activities.....................................      16,865      (3,870)
                                                                                            ----------  ----------
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures on fiber optic transmission network and related equipment............     (71,739)     (1,522)
Deposit...................................................................................      (4,675)         --
Investment in/advances to joint venture...................................................      (2,745)         --
Capital expenditures on property and equipment............................................      (1,109)       (225)
                                                                                            ----------  ----------
  Net cash used in investing activities...................................................     (80,268)     (1,747)
                                                                                            ----------  ----------
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock....................................................         892          10
Proceeds from issuance of preferred stock and warrants....................................          --      32,500
Dividends paid on preferred stock.........................................................          --         (77)
Repayments of notes payable and private placement.........................................          --      (1,408)
Repayments of notes payable...............................................................          --      (5,950)
Purchase of common stock..................................................................          --      (1,140)
Purchase of preferred stock...............................................................          --      (2,038)
                                                                                            ----------  ----------
  Net cash provided by financing activities...............................................         892      21,897
                                                                                            ----------  ----------
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS......................................     (62,511)     16,280
CASH AND CASH EQUIVALENTS-BEGINNING OF PERIOD.............................................     138,846         464
                                                                                            ----------  ----------
CASH AND CASH EQUIVALENTS-END OF PERIOD...................................................  $   76,335  $   16,744
                                                                                            ----------  ----------
                                                                                            ----------  ----------
Supplemental information:
  Interest paid...........................................................................  $       16  $    1,145
                                                                                            ----------  ----------
                                                                                            ----------  ----------
  Income taxes paid.......................................................................  $    3,080  $       --
                                                                                            ----------  ----------
                                                                                            ----------  ----------
Supplemental disclosure of significant non-cash investing activities:
  Capital lease obligations...............................................................  $   19,742  $       --
                                                                                            ----------  ----------
                                                                                            ----------  ----------
  Accrued capital expenditures............................................................  $   32,743  $       --
                                                                                            ----------  ----------
                                                                                            ----------  ----------
</TABLE>
 
                             See accompanying notes
 
                                      F-4
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
BUSINESS OPERATIONS AND LINE OF BUSINESS
 
    We are a facilities-based provider of technologically advanced,
high-bandwidth, fiber optic communications infrastructure to communications
carriers and corporate/government customers in the United States. We focus our
operations on domestic intra-city fiber optic networks in clusters of Tier I
cities throughout the United States. We currently operate high-bandwidth fiber
optic communications networks in New York and within the next two quarters
expect to operate similar networks in Philadelphia and Washington, D.C. We have
also begun constructing and engineering networks in Chicago, San Francisco and
Boston and within the next two years we also plan to complete an expansion into
four additional markets including Los Angeles, Seattle, Dallas and Houston. We
expect that our domestic intra-city networks will ultimately encompass
approximately 756,000 fiber miles covering approximately 1,771 route miles.
 
    We have also built inter-city fiber optic capacity to link certain of our
intra-city networks. We expect to have operational a 241 route mile network from
New York to Washington, D.C. during the first quarter of 1999, and when finally
complete, as currently planned, this network will cover approximately 180,000
fiber miles. We have also obtained rights for fiber optic capacity with other
facilities-providers and obtained fiber optic capacity linking certain of the
metropolitan areas (New York and Chicago, New York and Boston, Chicago and
Seattle and Portland) in which we plan to construct intra-city networks, except
in Portland.
 
    In addition, we have entered into a joint venture with a U.K.
telecommunications company to connect our New York network to London and we have
announced that we intend to form a joint venture to construct a high-bandwidth
fiber optic network connecting 13 cities in Germany and obtain certain
additional fiber optic capacity in Western Europe. Please refer to the sections
in this Offering Memorandum entitled "Business" and "Risk Factors and Risks
Associated with Growth Strategy; Management of Expansion."
 
BASIS OF PRESENTATION
 
    The interim unaudited consolidated financial statements in this Report have
been prepared in accordance with the United States Securities and Exchange
Commission's Regulation S-X and consequently do not include all disclosures
required under generally accepted accounting principles. The interim unaudited
consolidated financial statements should be read in conjunction with the audited
Consolidated Financial Statements of the Company and accompanying Notes for the
year ended December 31, 1997 contained in the Company's Annual Report on Form
10-K for the year then ended. The Form 10-K includes information with respect to
the Company's significant accounting and financial reporting policies and other
pertinent information. The Company believes that all adjustments of a normal
recurring nature that are necessary for a fair presentation of the results of
the interim periods presented in this report have been made. Certain balances
have been reclassified to conform to the current period presentation.
 
STOCK SPLITS
 
    On December 22, 1998, the Company completed a two-for-one stock split of the
Company's Class A and Class B Common Stock in the form of a 100% stock dividend
to all shareholders of record as of the close of business on December 8, 1998.
On August 28, 1998, the Company completed a
 
                                      F-5
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
       NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) (CONTINUED)
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
two-for-one stock split of the Company's Class A and Class B Common Stock in the
form of a 100 percent stock dividend to all shareholders of record as of the
close of business on August 7, 1998. All share and per share amounts presented
herein give retroactive effect to the stock splits. (See note 8.)
 
RECOGNITION OF REVENUE
 
    The Company recognizes revenue on telecommunications services ratably over
the term of the applicable lease agreements with customers. Amounts billed in
advance of the service provided are recorded as deferred revenue. The Company
also provides installation services for its customers, and as these services
typically are completed within a year, the Company records the revenues and
related costs for these services under the completed contract method. In
addition, the Company occasionally grants Indefeasible Rights of Use ("IRU's")
to portions of its network. For those grants occurring prior to completion of
the portion of the network granted, the Company recognizes revenue on these
telecommunication services using the percentage of completion method. Under the
percentage of completion method, progress is generally measured on performance
milestones relating to the contract where such milestones fairly reflect the
progress toward contract completion. Network construction costs include all
direct material and labor costs and those indirect costs related to contract
performance. General and administrative costs are charged to expense as
incurred. If necessary, the estimated loss on an uncompleted contract is
expensed in the period in which it is identified. Contract costs are estimated
using allocations of the total cost of constructing the specific phase of the
network. Revisions to estimated profits on contracts are recognized in the
period that they become known.
 
2. CONSULTING AND EMPLOYMENT INCENTIVES
 
    The amounts represent the value of common stock, warrants and options issued
to consultants, officers, employees and directors of the Company as incentive to
provide services to the Company.
 
    The 1997 amounts represent the value of options to purchase 12,380,940
shares of the Company's common stock issued in 1997 to officers, employees and
directors of the Company. The options have been valued in accordance with APB
Opinion No. 25 at the difference between the exercise price of the options and
the fair market value of the Company's common stock.
 
                                      F-6
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
       NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) (CONTINUED)
 
3. FIBER OPTIC TRANSMISSION NETWORK AND RELATED EQUIPMENT
 
    Fiber optic transmission network and related equipment consist of the
following (in 000's):
 
<TABLE>
<CAPTION>
                                                                                                     SEPTEMBER 30,
                                                                                                         1998
                                                                                                     -------------
<S>                                                                                                  <C>
Material-fiber optic cable.........................................................................   $     4,900
Engineering and layout costs.......................................................................         4,123
Fiber optic cable installation costs...............................................................         2,668
Other..............................................................................................         2,750
Construction in progress...........................................................................       135,960
                                                                                                     -------------
                                                                                                          150,401
Less: accumulated depreciation.....................................................................        (1,822)
                                                                                                     -------------
                                                                                                      $   148,579
                                                                                                     -------------
                                                                                                     -------------
</TABLE>
 
    Construction in progress includes amounts incurred in the Company's
expansion of its network. These amounts include fiber optic cable and other
materials, engineering and other layout costs, fiber optic cable installation
costs and other network assets held under capital leases. Construction in
progress also includes payments for rights of way for the underlying sections of
the network build.
 
4. INVESTMENT IN/ADVANCES TO JOINT VENTURE
 
    The Company has a joint venture agreement with Racal Telecommunications,
Inc. ("Racal"), that provides broad-based transatlantic communication services
between New York and London. As of December 31, 1997, neither party had yet made
a capital contribution. The balance of the investment at December 31, 1997
represents advances made to the joint venture by the Company. The Company
accounts for its investment using the equity method. During the first nine
months of 1998, each party made capital contributions of $2.8 million. The
Company and Racal may each be required to contribute additional capital as
needed for their respective 50% interests. As of September 30, 1998, the Company
recorded a $264,000 loss from the joint venture based on its 50% interest in the
joint venture. Included in the Company's accounts receivable is $168,000 for
administrative services provided to the joint venture through September 30,
1998.
 
5. GERMAN NETWORK BUILD
 
    The Company signed a letter of intent with Viatel, Inc. and Carrier 1
Holdings, Ltd. to jointly build a national fiber optic telecommunications
network in Germany. Upon completion of construction, the Company will own its
own separate German broadband network. The Company expects construction to be
completed in stages, with the first segment expected to be available by the
third quarter of 1999. In connection with this agreement, the Company made a
deposit payment of $4.7 million. Upon signing a definitive agreement the Company
would expect to be required to provide an irrevocable standby letter of credit
as security for the construction costs of the network.
 
6. RELATED PARTY TRANSACTIONS
 
    The Company is party to the Management Agreement with Metromedia Company
pursuant to which Metromedia Company provides the Company with consultation and
advisory services. These services encompass legal, insurance, personnel,
benefits and other corporate matters, cash management,
 
                                      F-7
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
       NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) (CONTINUED)
 
6. RELATED PARTY TRANSACTIONS (CONTINUED)
internal audit, finance, taxes and other services as may be reasonably requested
by the Company. The Management Agreement terminates on December 31, 1998 and is
automatically renewed for successive one-year terms unless either party
terminates upon 60 days notice. The management fee under the Management
Agreement is $500,000 per year. In addition, the Company is obligated to
reimburse Metromedia Company all of its out-of-pocket costs and expenses
incurred in connection with the agreement.
 
    In fiscal 1997, Metromedia Company received no payments for its
out-of-pocket costs and expenses or for any other services rendered under the
Management Agreement. With respect to 1998, in accordance with the Management
Agreement, amounts expensed as of September 30, 1998 were $375,000.
 
    In 1997, the Company paid in full the outstanding balance of a loan made to
the Company in prior years by the Company's majority shareholder at the time
such loan was advanced.
 
7. SETTLEMENT AGREEMENTS
 
    The Company was a defendant in KATZ, ET AL. V. NATIONAL FIBER NETWORK, INC.,
ET AL., No. 97 Civ. 2764 (JGK) (the "Katz Litigation"). The subject matter of
the Katz Litigation is set forth in detail in the Company's Annual Report on
Form 10-K for the year ended December 31, 1997, which description is
incorporated by reference herein and made a part hereof. In March 1998, the
Company entered into a settlement agreement with Howard Katz, Realprop Capital
Corporation and Evelyn Katz, among others, which settled and resulted in the
dismissal of the Katz Litigation.
 
8. EQUITY TRANSACTIONS
 
STOCK SPLITS
 
    As discussed in Note 1, on December 22, 1998, the Company completed a
two-for-one stock split of the Company's Class A and Class B Common Stock in the
form of a 100% stock dividend to all shareholders of record as of the close of
business on December 8, 1998 and on August 28, 1998, the Company completed a
two-for-one stock split of the Company's Class A and Class B Common Stock in the
form of a 100 percent stock dividend to all shareholders of record as of the
close of business on August 7, 1998. All share and per share amounts presented
herein give retroactive effect to the stock splits. As of September 30, 1998,
adjusted for the effect of the stock dividend, the Company had 77,460,452 Class
A common shares outstanding and 16,884,636 Class B common shares outstanding.
 
STOCK OPTIONS
 
    In 1997, the Company granted to key employees, officers and directors
options to purchase up to 12,380,940 shares of the common stock of the Company.
The options have exercise prices ranging from $0.49 to $1.91 per share, vesting
schedules ranging from immediate to twelve months from date of grant and expire
ten years after date of grant. The Company recorded non-cash charges of $53,000
and $248,000 for the three- and nine-month periods ending September 30, 1998,
respectively, to reflect the pro-rata value applicable to the vesting period of
such grants.
 
                                      F-8
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
       NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) (CONTINUED)
 
8. EQUITY TRANSACTIONS (CONTINUED)
STOCK WARRANTS
 
    On December 31, 1996, the Company issued and sold to Penny Lane Partners, LP
("Penny Lane") for aggregate cash consideration of $2,025,000 (i) 300,000 shares
of 10% cumulative convertible preferred stock (the "Series A Preferred Stock")
bearing dividends at a rate of $.34 per share per annum, and (ii) warrants to
purchase 456,300 shares of Common Stock at an exercise price of $1.24 per share
of Common Stock (such number to be adjusted based on certain future events) at
an exercise price of $0.01 per share (the "Contingent Warrants"). In March 1997,
Penny Lane agreed to permit the Series A Preferred Stock and the Contingent
Warrants to be redeemed at an aggregate redemption price of $2,115,000 (which
includes accrued but unpaid dividends on the Series A Preferred Stock) and in
connection therewith the number of Penny Lane Warrants was increased from
456,300 to 912,600.
 
    In January 1998, Penny Lane exercised all its warrants under the terms of
the agreement. Penny Lane elected to make a cashless exercise of its warrants
and the number of shares issuable upon exercise was reduced by the number of
shares at the closing price on the day of exercise having a value equal to the
aggregate exercise price. As such, Penny Lane was issued 691,024 shares in
connection with the exercise of all of its warrants.
 
9. CONTINGENCIES
 
    (a) On or about October 20, 1997, Vento & Company of New York, LLC ("VCNY")
commenced an action against the Company, Stephen A. Garofalo, Peter Silverman,
the law firm of Silverman, Collura, Chernis & Balzano, P.C., Peter Sahagen,
Sahagen Consulting Group of Florida (collectively, the "Sahagen Defendants") and
Robert Kramer, Birdie Capital Corp., Lawrence Black, Sterling Capital LLC,
Penrush Limited, Needham Capital Group, Arthur Asch, Michael Asch and Ronald
Kuzon (the "Kramer Defendants") in the United States District Court for the
Southern District of New York (No. 97 CIV 7751) (the "VCNY Litigation"). On or
about May 29, 1998, plaintiff filed an amended complaint. The complaint, as
amended, alleges four causes of action including (i) violation of Section 10(b)
of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder;
(ii) fraud and fraudulent concealment; (iii) breach of fiduciary duty; and (iv)
negligent misrepresentation and omission made in connection with the sale by
VCNY of 900,000 shares (not adjusted for subsequent stock splits) of Class A
common stock to Peter Sahagen and the Kramer Defendants on January 13, 1997 (the
"VCNY Sale"). Plaintiff seeks, among other things, (i) on the first and second
causes of action, rescission of the VCNY Sale, or alternatively, damages in an
amount not presently ascertainable, but believed to be in excess of $36 million,
together with interest thereon; (ii) on the third and fourth causes of action,
damages in an amount not presently ascertainable, but believed to be in excess
of $36 million, together with interest thereon; (iii) punitive damages in the
amount of $50 million, and (iv) plaintiff's reasonable legal fees and the cost
of this action. All the defendants, including the Company and Stephen A.
Garofalo, have moved to dismiss the amended complaint. The Company intends to
vigorously defend itself against these allegations based on its belief that it
acted appropriately in connection with the matters at issue in this litigation.
However, no assurance can be made that the Company will not determine that the
advantages of entering into a settlement outweigh the risk and expense of
protracted litigation or that ultimately the Company will be successful in its
defense of the allegations. If the Company is unsuccessful in its defense of the
allegations, an award of the magnitude being sought by the plaintiff in the VCNY
Litigation would have a material adverse effect on the Company's financial
condition or results of operations.
 
                                      F-9
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
       NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) (CONTINUED)
 
9. CONTINGENCIES (CONTINUED)
    (b) On or about June 12, 1998, Claudio E. Contardi commenced an action
against Peter Sahagen, Sahagen Consulting Group of Florida and the Company in
the United States District Court for the Southern District of New York (No. 98
CIV 4140). The plaintiff alleges a cause of action for, among other things,
breach of a finder's fee agreement entered into between Peter Sahagen and
plaintiff on or about November 14, 1996 and breach of an implied covenant of
good faith and fair dealing contained in the finder's fee agreement. Plaintiff
seeks, among other things, a number of shares of the Company not presently
ascertainable, but believed to be approximately 225,000 shares (calculated as of
the date on which the complaint was filed) or damages in an amount not presently
ascertainable, but believed to be approximately $4.9 million (calculated as of
the date on which the complaint was filed) and all costs and expenses incurred
by the plaintiff in this action. The Company has answered the complaint and
asserted affirmative defenses thereto, and the Company intends to vigorously
defend itself against these allegations based on its belief that it acted
appropriately in connection with the matters at issue in this litigation.
However, no assurances can be made that the Company will not determine that the
advantages of entering into a settlement outweigh the risk and expense of
protracted litigation or that ultimately the Company will be successful in its
defense of the allegations. The Company has filed an answer to the complaint and
has raised affirmative defenses.
 
                                      F-10
<PAGE>
                         REPORT OF INDEPENDENT AUDITORS
 
To the Board of Directors and Shareholders of
 
  Metromedia Fiber Network, Inc.
 
    We have audited the accompanying consolidated balance sheets of Metromedia
Fiber Network, Inc. and Subsidiaries (the "Company") as of December 31, 1997 and
1996, and the related consolidated statements of operations, stockholders'
deficiency and cash flows for each of the years then ended. These consolidated
financial statements are the responsibility of the Company's management. Our
responsibility is to express an opinion on these consolidated financial
statements based on our audits.
 
    We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audits to obtain
reasonable assurance about whether the consolidated financial statements are
free of material misstatement. An audit includes examining, on a test basis,
evidence supporting the amounts and disclosures in the consolidated financial
statements. An audit also includes assessing the accounting principles used and
significant estimates made by management, as well as evaluating the overall
consolidated financial statement presentation. We believe that our audits
provide a reasonable basis for our opinion.
 
    In our opinion, the consolidated financial statements referred to above
present fairly, in all material respects, the consolidated financial position of
Metromedia Fiber Network, Inc. and Subsidiaries as of December 31, 1997 and
1996, and the consolidated results of their operations and their cash flows for
the years then ended in conformity with generally accepted accounting
principles.
 
                                          Ernst & Young LLP
 
New York, New York
March 16, 1998
 
                                      F-11
<PAGE>
                         REPORT OF INDEPENDENT AUDITORS
 
To the Board of Directors and Shareholders of
  Metromedia Fiber Network, Inc.
 
    We have audited the accompanying consolidated statements of operations,
stockholders' deficiency and cash flows for the year ended December 31, 1995 of
Metromedia Fiber Network, Inc. and Subsidiary (the "Company"). These
consolidated financial statements are the responsibility of the Company's
management. Our responsibility is to express an opinion on these consolidated
financial statements based on our audit.
 
    We conducted our audit in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audits to obtain
reasonable assurance about whether the consolidated financial statements are
free of material misstatement. An audit includes examining, on a test basis,
evidence supporting the amounts and disclosures in the consolidated financial
statements. An audit also includes assessing the accounting principles used and
significant estimates made by management, as well as evaluating the overall
consolidated financial statement presentation. We believe that our audit
provides a reasonable basis for our opinion.
 
    In our opinion, the consolidated financial statements referred to above
present fairly, in all material respects, the consolidated results of operations
and cash flows for the year ended December 31, 1995 of Metromedia Fiber Network,
Inc. and Subsidiary in conformity with generally accepted accounting principles.
 
    The accompanying consolidated financial statements have been prepared
assuming that the Company will continue as a going concern. As discussed in Note
1 to the consolidated financial statements, the Company's significant recurring
losses, operating history and significant working capital deficiency, including
significant amounts of past due payables, raise substantial doubt about the
Company's ability to continue as a going concern. Management's plans in regard
to these matters are also discussed in Note 1. The consolidated financial
statements do not include any adjustments relating to the recoverability and
classification of recorded asset amounts or the amounts and classification of
liabilities that might result from the outcome of this uncertainty.
 
                                          M.R. Weiser & Co. LLP
 
New York, New York
June 26, 1996
 
                                      F-12
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
                          CONSOLIDATED BALANCE SHEETS
 
<TABLE>
<CAPTION>
                                                                                            DECEMBER 31,
                                                                                   ------------------------------
<S>                                                                                <C>             <C>
                                                                                        1997            1996
                                                                                   --------------  --------------
                                                     ASSETS
Current assets:
  Cash and cash equivalents......................................................  $  138,846,458  $      464,324
  Accounts receivable............................................................         836,628         180,790
  Other current assets...........................................................         874,010        --
                                                                                   --------------  --------------
    Total current assets.........................................................     140,557,096         645,114
Fiber optic transmission network and related equipment, net......................      24,933,510       6,368,653
Property and equipment, net......................................................         759,014         525,268
Investment in/advance to Joint Venture...........................................          56,015        --
Other assets.....................................................................       1,072,055         438,471
                                                                                   --------------  --------------
    Total assets.................................................................  $  167,377,690  $    7,977,506
                                                                                   --------------  --------------
                                                                                   --------------  --------------
 
                                LIABILITIES AND STOCKHOLDERS' EQUITY (DEFICIENCY)
Current liabilities:
  Accounts payable...............................................................  $    3,072,091  $    5,256,929
  Accrued expenses...............................................................       3,180,010         917,526
  Current portion of deferred revenue............................................       1,183,633        --
  Notes payable..................................................................        --             7,358,000
                                                                                   --------------  --------------
    Total current liabilities....................................................       7,435,734      13,532,455
Deferred revenue.................................................................      10,311,023       1,107,724
Other............................................................................          90,000         195,243
Commitments and Contingencies
Stockholders' equity (deficiency):
Preferred stock, $.10 par value, authorized 2,000,000 shares, none and 600,000
  shares issued and outstanding, respectively....................................        --                60,000
Common stock, $.01 par value; authorized 60,000,000 shares; none and 40,005,240
  shares issued and outstanding, respectively....................................        --               400,051
Class A common stock, $.01 par value; authorized 180,000,000 shares; 74,896,568
  shares and none issued and outstanding, respectively...........................         748,966        --
Class B common stock, $.01 par value; authorized 20,000,000 shares; 16,884,636
  shares and none issued outstanding, respectively...............................         168,846        --
Additional paid-in capital.......................................................     191,845,909       8,421,468
Accumulated deficit..............................................................     (43,222,788)    (15,739,435)
                                                                                   --------------  --------------
    Total stockholders' equity (deficiency)......................................     149,540,933      (6,857,916)
                                                                                   --------------  --------------
      Total liabilities and stockholders' equity (deficiency)....................  $  167,377,690  $    7,977,506
                                                                                   --------------  --------------
                                                                                   --------------  --------------
</TABLE>
 
                            See accompanying notes.
 
                                      F-13
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
                     CONSOLIDATED STATEMENTS OF OPERATIONS
 
<TABLE>
<CAPTION>
                                                                           FOR THE YEAR ENDED DECEMBER 31,
                                                                    ---------------------------------------------
<S>                                                                 <C>             <C>             <C>
                                                                         1997            1996           1995
                                                                    --------------  --------------  -------------
Revenues..........................................................  $    2,524,311  $      236,082  $      56,149
Expenses:
  Cost of sales...................................................       3,572,005         698,793       --
  Selling, general and administrative.............................       6,303,041       2,070,345      3,886,568
  Consulting and employment incentives............................      19,218,591       3,652,101
  Depreciation and amortization...................................         757,133         612,530        161,576
                                                                    --------------  --------------  -------------
Loss from operations..............................................     (27,326,459)     (6,797,687)    (3,991,995)
Interest income...................................................       1,808,007        --             --
Interest expense (including financing costs)......................        (740,786)     (3,561,010)      (327,106)
                                                                    --------------  --------------  -------------
Net loss..........................................................     (26,259,238)    (10,358,697)    (4,319,101)
                                                                    --------------  --------------  -------------
                                                                    --------------  --------------  -------------
Net loss per share-basic and diluted..............................  $         (.56) $        (0.29) $       (0.17)
                                                                    --------------  --------------  -------------
                                                                    --------------  --------------  -------------
</TABLE>
 
                            See accompanying notes.
 
                                      F-14
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
 
<TABLE>
<CAPTION>
                                                                               YEAR ENDED DECEMBER 31,
                                                                    ---------------------------------------------
                                                                         1997            1996           1995
                                                                    --------------  --------------  -------------
<S>                                                                 <C>             <C>             <C>
Cash flows from operating activities:
Net loss..........................................................  $  (26,259,238) $  (10,358,697) $  (4,319,101)
Adjustments to reconcile net loss to net cash (used in) provided
  by operating activities:
  Depreciation and amortization...................................         757,133         612,530        161,576
  Stock, options and warrants issued for services.................      19,438,627       5,395,132       --
Changes in operating assets and liabilities:
  Accounts receivable.............................................        (655,838)          1,928       (182,718)
  Accounts payable and accrued expenses...........................         (12,354)        757,897      2,916,058
  Advance payments received from customers........................      10,386,932         832,690        275,034
  Other...........................................................      (1,467,609)         12,930       (141,666)
                                                                    --------------  --------------  -------------
    Net cash provided (used) in operating activities..............       2,187,653      (2,745,590)    (1,290,817)
                                                                    --------------  --------------  -------------
Cash flows from investing activities:
Capital expenditures on fiber optic transmission network and
  related equipment...............................................     (19,205,912)       (974,107)    (3,709,928)
Deposit on fiber optic cable order................................         (86,771)       --             --
Investment in/advance to joint venture............................         (56,015)       --             --
Capital expenditures on property and equipment....................        (318,281)        (95,356)      (476,378)
                                                                    --------------  --------------  -------------
    Net cash used in investing activities.........................     (19,666,979)     (1,069,463)    (4,186,306)
                                                                    --------------  --------------  -------------
Cash flows from financing activities:
  Proceeds from issuance of common stock..........................     133,974,844         123,500       --
  Proceeds from issuance of preferred stock and warrants..........      32,500,000       2,025,000       --
  Dividends paid on preferred stock...............................         (76,562)       --             --
  (Repayments) proceeds from notes payable-private placement......      (1,408,000)         25,000      1,383,000
  (Repayments) of notes payable...................................      (5,950,000)     (3,350,036)      --
  Proceeds from notes payable.....................................        --             5,450,000      3,850,036
  Purchase of common stock........................................      (1,140,384)       --             --
  Purchase of preferred stock.....................................      (2,038,438)       --             --
                                                                    --------------  --------------  -------------
    Net cash provided by financing activities.....................     155,861,460       4,273,464      5,233,036
                                                                    --------------  --------------  -------------
Net increase in cash and cash equivalents.........................     138,382,134         458,411       (244,087)
Cash and cash equivalents and beginning of period.................         464,324           5,913        250,000
                                                                    --------------  --------------  -------------
Cash and cash equivalents and end of period.......................  $  138,846,458  $      464,324  $       5,913
                                                                    --------------  --------------  -------------
                                                                    --------------  --------------  -------------
Supplemental information: Interest paid...........................  $    1,145,416  $      996,060  $      67,149
                                                                    --------------  --------------  -------------
                                                                    --------------  --------------  -------------
Income taxes paid.................................................  $     --        $     --        $    --
                                                                    --------------  --------------  -------------
                                                                    --------------  --------------  -------------
</TABLE>
 
                            See accompanying notes.
 
                                      F-15
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
    CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' (DEFICIENCY) EQUITY
<TABLE>
<CAPTION>
                                                                                                                    CLASS A
                                               SERIES A                SERIES B                                     COMMON
                                           PREFERRED STOCK         PREFERRED STOCK            COMMON STOCK           STOCK
                                         --------------------  ------------------------  -----------------------  -----------
                                          SHARES     AMOUNT      SHARES       AMOUNT       SHARES       AMOUNT      SHARES
                                         ---------  ---------  -----------  -----------  -----------  ----------  -----------
<S>                                      <C>        <C>        <C>          <C>          <C>          <C>         <C>
Balance at December 31, 1994...........     --      $  --          --        $  --        24,336,000  $  243,360      --
Issuance of common stock as an
  inducement for entering into a loan
  agreement............................     --         --          --           --           623,976       6,240      --
Net loss for the year..................     --         --          --           --           --           --          --
                                         ---------  ---------  -----------  -----------  -----------  ----------  -----------
Balance at December 31, 1995...........     --         --          --           --        24,959,976     249,600      --
Issuance of common stock in 1996 for
  legal services rendered..............     --         --          --           --         1,964,420      19,644      --
Issuance of common stock and warrants
  in conjunction with sale of Senior
  Subordinated Notes in 1996...........     --         --          --           --         1,524,348      15,244      --
Issuance of shares to holder of Senior
  Subordinated Notes in exchange for
  warrants.............................     --         --          --           --           912,600       9,126      --
Issuance of common stock in April 1996
  to extend maturity of private
  placement Subordinated Notes.........     --         --          --           --           237,436       2,374      --
Issuance of common stock in exchange
  for management services..............     --         --          --           --         6,084,000      60,840      --
Issuance of additional common stock to
  the holder of the Senior Subordinated
  Notes in connection with antidilution
  provisions...........................     --         --          --           --           152,100       1,521      --
Issuance of common stock in April 1996
  and July 1996 in connection with the
  exercise of warrants.................     --         --          --           --           762,172       7,622      --
Issuance of common stock to related
  electrical contractor in May 1996 as
  payment for services.................     --         --          --           --         1,825,200      18,252      --
Issuance of common stock to majority
  shareholder in May 1996 in exchange
  for debt.............................     --         --          --           --           608,400       6,084      --
Sale of common stock and warrants in
  June 1996............................     --         --          --           --           152,100       1,521      --
Issuance of common stock in July 1996
  in exchange for services rendered....     --         --          --           --            48,672         486      --
Issuance of common stock for services
  rendered.............................     --         --          --           --           730,080       7,300      --
Sale of common stock in September
  1996.................................     --         --          --           --            43,736         437      --
 
<CAPTION>
 
                                                          CLASS B
                                                        COMMON STOCK       ADDITIONAL
                                                    --------------------     PAID-IN     ACCUMULATED
                                          AMOUNT     SHARES     AMOUNT       CAPITAL       DEFICIT         TOTAL
                                         ---------  ---------  ---------  -------------  ------------  -------------
<S>                                      <C>        <C>        <C>        <C>            <C>           <C>
Balance at December 31, 1994...........  $  --         --      $  --      $    (203,360) $ (1,061,637) $  (1,021,637)
Issuance of common stock as an
  inducement for entering into a loan
  agreement............................     --         --         --             (1,240)      --               5,000
Net loss for the year..................     --         --         --           --          (4,319,101)    (4,319,101)
                                         ---------  ---------  ---------  -------------  ------------  -------------
Balance at December 31, 1995...........     --         --         --           (204,600)   (5,380,738)    (5,335,738)
Issuance of common stock in 1996 for
  legal services rendered..............     --         --         --            887,657       --             907,301
Issuance of common stock and warrants
  in conjunction with sale of Senior
  Subordinated Notes in 1996...........     --         --         --            673,769       --             689,013
Issuance of shares to holder of Senior
  Subordinated Notes in exchange for
  warrants.............................     --         --         --             (9,126)      --            --
Issuance of common stock in April 1996
  to extend maturity of private
  placement Subordinated Notes.........     --         --         --            104,948       --             107,322
Issuance of common stock in exchange
  for management services..............     --         --         --          2,699,160       --           2,760,000
Issuance of additional common stock to
  the holder of the Senior Subordinated
  Notes in connection with antidilution
  provisions...........................     --         --         --             (1,521)      --            --
Issuance of common stock in April 1996
  and July 1996 in connection with the
  exercise of warrants.................     --         --         --             (7,622)      --            --
Issuance of common stock to related
  electrical contractor in May 1996 as
  payment for services.................     --         --         --            674,635       --             692,887
Issuance of common stock to majority
  shareholder in May 1996 in exchange
  for debt.............................     --         --         --            593,916       --             600,000
Sale of common stock and warrants in
  June 1996............................     --         --         --             98,479       --             100,000
Issuance of common stock in July 1996
  in exchange for services rendered....     --         --         --             20,714       --              21,200
Issuance of common stock for services
  rendered.............................     --         --         --            327,500       --             334,800
Sale of common stock in September
  1996.................................     --         --         --             23,063       --              23,500
</TABLE>
 
                                      F-16
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
    CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' (DEFICIENCY) EQUITY
                                  (CONTINUED)
<TABLE>
<CAPTION>
                                            SERIES A               SERIES B                                          CLASS A
                                        PREFERRED STOCK        PREFERRED STOCK            COMMON STOCK             COMMON STOCK
                                      --------------------  ----------------------  ------------------------  ----------------------
                                       SHARES     AMOUNT     SHARES      AMOUNT        SHARES       AMOUNT      SHARES      AMOUNT
                                      ---------  ---------  ---------  -----------  ------------  ----------  -----------  ---------
<S>                                   <C>        <C>        <C>        <C>          <C>           <C>         <C>          <C>
Issuance of warrants for legal
  services rendered (to purchase
  608,400 shares at $0.015 per
  share)............................     --         --         --          --            --           --          --          --
Issuance of warrants in connection
  with debt issuance (to purchase
  377,208 shares at $1.48 per
  share)............................     --         --         --          --            --           --          --          --
Issuance of warrants in connection
  with debt issuance (to purchase
  762,172 shares at $.002 per
  share)............................     --         --         --          --            --           --          --          --
Issuance of warrants in connection
  with debt issuance (to purchase
  428,312 shares at $2.00 per
  share)............................     --         --         --          --            --           --          --          --
Sale of preferred stock with
  warrants in December 1996.........    600,000     60,000     --          --            --           --          --          --
Net loss for the year...............     --         --         --          --            --           --          --          --
                                      ---------  ---------  ---------       -----   ------------  ----------  -----------  ---------
Balance at December 31, 1996........    600,000     60,000     --          --         40,005,240     400,051      --          --
Issuance of common stock in
  connection with the exercise of
  warrants..........................     --         --         --          --            608,400       6,084      --          --
Issuance of options to employees,
  officers and directors (to
  purchase 12,380,940 shares).......     --         --         --          --            --           --          --          --
Issuance of warrants in connection
  with debt extension (to purchase
  230,728 shares at $2.00 per
  share)............................     --         --         --          --            --           --          --          --
Dividends on preferred stock........     --         --         --          --            --           --          --          --
Repurchase and retirement of Series
  A preferred stock and warrants....   (600,000)   (60,000)    --          --            --           --          --          --
Repurchase and retirement of common
  stock and warrants................     --         --         --          --         (2,353,880)    (23,539)         (68)    --
Sales of Series B preferred stock...     --         --          8,403          84        --           --          --          --
Initial Public Offering.............     --         --         --          --            --           --       36,432,000    364,320
Conversion of Common Stock to Series
  A Common Stock....................     --         --         --          --        (38,259,760)   (382,596)  38,259,760    382,596
Conversion of Series B Preferred
  Stock to Series A and B Common
  Stock.............................     --         --         (8,403)        (84)       --           --          157,308      1,574
Issuance of common stock in
  connection with the exercise of
  warrants..........................     --         --         --          --            --           --           47,568        476
Net loss for the year...............     --         --         --          --            --           --          --          --
                                      ---------  ---------  ---------       -----   ------------  ----------  -----------  ---------
Balance at December 31, 1997........     --      $  --         --       $  --            --       $   --       74,896,568  $ 748,966
 
<CAPTION>
                                             CLASS B
                                           COMMON STOCK        ADDITIONAL
                                      ----------------------     PAID-IN      ACCUMULATED
                                        SHARES      AMOUNT       CAPITAL        DEFICIT         TOTAL
                                      -----------  ---------  -------------  -------------  -------------
<S>                                   <C>          <C>        <C>            <C>            <C>
Issuance of warrants for legal
  services rendered (to purchase
  608,400 shares at $0.015 per
  share)............................      --          --            200,000       --              200,000
Issuance of warrants in connection
  with debt issuance (to purchase
  377,208 shares at $1.48 per
  share)............................      --          --             13,640       --               13,640
Issuance of warrants in connection
  with debt issuance (to purchase
  762,172 shares at $.002 per
  share)............................      --          --            250,550       --              250,550
Issuance of warrants in connection
  with debt issuance (to purchase
  428,312 shares at $2.00 per
  share)............................      --          --            111,306       --              111,306
Sale of preferred stock with
  warrants in December 1996.........      --          --          1,965,000       --            2,025,000
Net loss for the year...............      --          --           --          (10,358,697)   (10,358,697)
                                      -----------  ---------  -------------  -------------  -------------
Balance at December 31, 1996........      --          --          8,421,468    (15,739,435)    (6,857,916)
Issuance of common stock in
  connection with the exercise of
  warrants..........................      --          --              3,916       --               10,000
Issuance of options to employees,
  officers and directors (to
  purchase 12,380,940 shares).......      --          --         19,218,591       --           19,218,591
Issuance of warrants in connection
  with debt extension (to purchase
  230,728 shares at $2.00 per
  share)............................      --          --            220,036       --              220,036
Dividends on preferred stock........      --          --                           (76,562)       (76,562)
Repurchase and retirement of Series
  A preferred stock and warrants....      --          --         (1,965,000)       (13,438)    (2,038,438)
Repurchase and retirement of common
  stock and warrants................      --          --             17,270     (1,134,115)    (1,140,384)
Sales of Series B preferred stock...      --          --         32,499,916       --           32,500,000
Initial Public Offering.............      --          --        133,514,303       --          133,878,623
Conversion of Common Stock to Series
  A Common Stock....................      --          --           --             --             --
Conversion of Series B Preferred
  Stock to Series A and B Common
  Stock.............................   16,884,636    168,846       (170,336)      --             --
Issuance of common stock in
  connection with the exercise of
  warrants..........................      --          --             85,745       --               86,221
Net loss for the year...............      --          --           --          (26,259,238)   (26,259,238)
                                      -----------  ---------  -------------  -------------  -------------
Balance at December 31, 1997........   16,884,636  $ 168,846  $ 191,845,909  $ (43,222,788) $ 149,540,933
</TABLE>
 
                            See accompanying notes.
 
                                      F-17
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
BUSINESS OPERATIONS AND LINE OF BUSINESS
 
    Metromedia Fiber Network, Inc. (formerly National Fiber Network, Inc.) and
its subsidiaries (the "Company") was granted a nonexclusive right from the City
of New York, effective December 20, 1993, to provide telecommunication services
and construct a fiber optic network for the purpose of providing these services.
In October 1995, the basic backbone of the Fiber Optic Cable Network in the City
of New York was completed and the Company began servicing its customers.
 
    The Company entered into a joint venture agreement with Racal
Telecommunications, Inc. ("Racal") on November 26, 1997. The joint venture will
enable the Company and Racal to provide broadband transatlantic communication
services, between New York and London, to their respective customers. Racal is
part of the Racal Electronics Group which is headquartered in the United
Kingdom.
 
    The accompanying consolidated financial statements have been prepared on a
going concern basis which contemplates the realization of assets and the
satisfaction of liabilities in the normal course of business. On April 30, 1997
the Company sold 8,403 shares of Series B preferred shares in exchange for
$32,500,000 in cash. Prior thereto, the Company had working capital deficiencies
and stockholders' deficiencies. Further, substantially all of its trade payables
and certain current liabilities were past due. These factors, prior to the April
1997 sale of preferred stock, raised substantial doubt about the Company's
ability to continue as a going concern.
 
BASIS OF PRESENTATION
 
    The consolidated financial statements include the accounts of the Company
and it subsidiaries. All intercompany balances and transactions have been
eliminated in consolidation. The investment in the Racal joint venture in which
the Company owns 50% is accounted for by the equity method. Certain balances
have been restated to conform to the current period presentation.
 
ESTIMATES
 
    The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affect the reported amounts of assets and liabilities at the
date of the financial statements and the reported amounts of revenues and
expenses during the reporting period. Actual results could differ from those
estimates.
 
CASH AND CASH EQUIVALENTS
 
    For purposes of the consolidated financial statements the Company considers
all highly liquid investments with an original maturity of three months or less
when purchased to be cash equivalents.
 
FIBER OPTIC TRANSMISSION NETWORK AND RELATED EQUIPMENT
 
    The fiber optic transmission network and related equipment are stated at
cost. Costs in connection with the installation and expansion of the network are
capitalized. Depreciation is computed using the straight-line method through the
life of either the franchise agreement or right of way for the related network.
 
                                      F-18
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
PROPERTY AND EQUIPMENT
 
    Property and equipment are stated at cost. Depreciation is computed using
the straight-line method over the estimated useful lives of the assets.
 
FRANCHISE COSTS
 
    Amortization of franchise costs on the New York City Network began upon
commencement of service to customers and is computed on the straight-line method
through December 20, 2008 (159 months), the expiration date of the franchise
agreement.
 
ORGANIZATION COSTS
 
    Costs incurred in connection with the organization of the company were
capitalized and are being amortized over five years on a straight-line basis.
 
LONG-LIVED ASSETS
 
    The Company reviews for the impairment of long-lived assets and certain
identifiable intangibles whenever events or changes in circumstances indicate
that the carrying amount of an asset may not be recoverable. No such impairment
indicators have been identified by the Company.
 
INCOME TAXES
 
    The Company recognizes deferred tax liabilities and assets, if any, for the
expected future tax consequences of events that have been included in the
financial statements or tax returns. Under this method, deferred tax liabilities
and assets are determined based on the difference between the financial
statement and tax bases of assets and liabilities using enacted tax rates in
effect for the year in which the differences are expected to reverse. Valuation
allowances are provided when the expected realization of tax assets does not
meet a more likely than not criterion.
 
RECAPITALIZATIONS
 
    On February 17, 1995, the Company effected a 4,000-for-one stock split of
its outstanding shares of common stock. In April 1997, the Company increased its
authorized common stock of $.01 par value to 60,000,000 shares; in addition,
authorized preferred stock with a par value of $.01 was increased to 2,000,000
shares. On April 29, 1997, the Company effected a 3-for-one stock split of its
outstanding shares of common stock. In September 1997, the Company effected a
 .507-for-1 reverse stock split of its common stock. On October 28, 1997, the
total authorized number of shares of common stock of the Company was increased
to 200 million shares, par value $0.01 per share, of which 180 million shares
were designated Class A common stock and 20 million shares were designated Class
B common stock.
 
    On August 28, 1998, the Company completed a two-for-one stock split of the
Company's Class A and Class B common stock in the form of a 100 percent stock
dividend. On December 22, 1998, the Company completed a two-for-one stock split
of the Company's Class A and Class B common stock in the form of a 100% stock
dividend. The accompanying financial statements give retroactive effect to the
above recapitalizations.
 
                                      F-19
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
RECOGNITION OF REVENUE
 
    The Company recognizes revenue on telecommunications services ratably over
the term of the applicable agreements with customers. The Company also provides
installation services for its customers, and as these services typically are
completed within a year, the Company records the revenues and related costs for
these services under the completed contract method.
 
STOCK-BASED COMPENSATION
 
    The Company has adopted the disclosure-only provisions of SFAS No. 123,
"Accounting for Stock-Based Compensation." The Company applies APB Opinion No.
25, "Accounting for Stock Issued to Employees," and related interpretations in
accounting for its stock options.
 
CONSULTING AND EMPLOYMENT INCENTIVES
 
    The amounts represent the value of common stock, warrants and options issued
to consultants, officers, employees and directors of the Company as incentive to
provide services to the Company. The 1997 amounts represent the value of options
to purchase 12,380,940 shares of the Company's common stock issued in 1997 to
officers, employees and directors of the Company. The options have been valued
in accordance with APB Opinion No. 25 at the difference between the exercise
price of the options and the fair market value of the Company's common stock.
 
EARNINGS PER SHARE
 
    The Company, as required, adopted SFAS No. 128, "Earnings Per Share," for
the year end 1997. All prior period earnings per share data have been restated.
Net loss per share computations are based upon the net loss attributable to
common shareholders divided by the weighted average number of shares of common
stock outstanding during the respective periods. The effect of stock options and
warrants, using the treasury stock method in computing diluted earnings per
share, is anti-dilutive.
 
RESTRICTED CASH
 
    In 1997, the Company entered into agreements regarding the issuance of
long-term standby letters of credit with a financial institution whereby the
financial institution required the Company to maintain collateral in the form of
an interest-bearing cash balance with the financial institution in the full
amount of the standby letters of credit issued. The restricted cash is invested
in short-term time deposits of the issuing financial institution and the
interest earned on the time deposits is free of restriction and released to the
Company periodically.
 
DEFERRED REVENUES
 
    Deferred revenue represents prepayments received from customers for future
use of the Company's fiber optic network as well as prepayment for installation
services which have not yet been provided. The Company derives revenues from
leasing dark fiber optic cable. Lease payments are structured as either
prepayments or monthly recurring charges. Prepayments are accounted for as
deferred revenues and recognized over the term of the respective customer lease
agreement. At December 31, 1997, the Company had received prepaid lease payments
totaling $11.5 million.
 
                                      F-20
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
2. FIBER OPTIC TRANSMISSION NETWORK AND RELATED EQUIPMENT
 
    Fiber optic transmission network and related equipment consist of the
following:
 
<TABLE>
<CAPTION>
                                                                                              DECEMBER 31,
                                                                                       ---------------------------
<S>                                                                                    <C>            <C>
                                                                                           1997           1996
                                                                                       -------------  ------------
Material-fiber optic cable...........................................................  $   1,133,916  $    719,067
Engineering and layout costs.........................................................      3,322,978     2,643,448
Fiber optic cable installation costs.................................................      1,869,119     1,205,041
Other................................................................................      2,016,852     1,279,397
Construction in progress.............................................................     17,835,000     1,125,000
                                                                                       -------------  ------------
                                                                                          26,177,865     6,971,953
Less: accumulated depreciation.......................................................     (1,244,355)     (603,300)
                                                                                       -------------  ------------
                                                                                       $  24,933,510  $  6,368,653
                                                                                       -------------  ------------
                                                                                       -------------  ------------
</TABLE>
 
3. PROPERTY AND EQUIPMENT
 
    Property and equipment consist of the following:
 
<TABLE>
<CAPTION>
                                                                                 DECEMBER 31,
                                                                            ----------------------
<S>                                                                         <C>         <C>         <C>
                                                                               1997        1996      USEFUL LIFE
                                                                            ----------  ----------  -------------
Leasehold improvements....................................................  $  537,962  $  528,958  174 months
Furniture, equipment and software.........................................     352,056      42,776  5 years
                                                                            ----------  ----------
                                                                               890,018     571,734
Less accumulated depreciation and amortization............................    (131,004)    (46,466)
                                                                            ----------  ----------
                                                                            $  759,014  $  525,268
                                                                            ----------  ----------
                                                                            ----------  ----------
</TABLE>
 
4. INVESTMENT IN/ADVANCES TO JOINT VENTURE
 
    On November 26, 1997, the Company entered into a joint venture agreement
with Racal, to provide broad-based transatlantic communication services between
New York and London. The Company and Racal will each be required to contribute
capital of $3,400,000 through October 1, 1998 for their respective 50%
interests. As of December 31, 1997, neither party had yet made a capital
contribution. The balance of the investment at December 31, 1997 represents
advances made to the joint venture by the Company.
 
5. RELATED PARTY TRANSACTIONS
 
    Prior to 1996, the Company engaged the services of an electrical contractor
controlled by the person who was then the Company's majority shareholder. During
1995, the Company incurred charges for labor and materials of $692,887. As of
December 31, 1995, $692,887 was owed to this related company. In May 1996, the
Company and the assignee of this related party entered into an agreement whereby
the full amount of this indebtedness was satisfied by the issuance of 1,825,200
shares of the Company's common stock. The value of the stock was based upon the
invoices rendered for services performed based upon negotiations between the
Company and the electrical contractor.
 
    The person who was then the Company's majority shareholder made loans to the
Company which at December 31, 1994 totaled $1,967,109. In April 1995, such
shareholder of the Company agreed to contribute to the Company's capital $1.7
million of amounts due to him. By agreement between the
 
                                      F-21
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
5. RELATED PARTY TRANSACTIONS (CONTINUED)
Company and such shareholder in May 1996 the transaction was rescinded. During
1995, the Company made repayments (net of additional advances) of $1,070,130. As
of December 31, 1995, the Company owed such shareholder $896,979. Pursuant to an
agreement dated May 21, 1996, the Company issued 608,400 shares of its common
stock to such shareholder in consideration for the cancellation of $600,000 of
the outstanding balance. In 1997, the remaining balance of the note was repaid
in full.
 
    In March and June 1997, the Company entered into two one-year leases for
office space with an affiliate. Subsequent to June 1997, the affiliate sold this
property. For the year ended December 31, 1997 office rent expenses for these
leases amounted to approximately $110,000.
 
6. NOTES PAYABLE
 
    Notes payable consisted of the following:
 
<TABLE>
<CAPTION>
                                                                                                        DECEMBER 31,
                                                                                                   -----------------------
<S>                                                                                     <C>        <C>        <C>
                                                                                                     1997         1996
                                                                                                   ---------  ------------
U.S. One Communications...............................................................         a)  $  --      $  4,900,000
Convertible Subordinated Notes........................................................         b)     --           858,000
Sterling Capital Bridge Loan..........................................................         c)     --           550,000
Subordinated Notes....................................................................         d)     --           550,000
AT&T Wireless.........................................................................         e)     --           500,000
Senior Subordinated Notes.............................................................         f)     --           --
                                                                                                   ---------  ------------
                                                                                                   $  --      $  7,358,000
                                                                                                   ---------  ------------
                                                                                                   ---------  ------------
</TABLE>
 
    A. On April 16, 1996, the Company entered into an agreement with U.S. One
Communications ("U.S. One") for the exclusive usage rights for fibers on the
Company's fiber optic transmission network. The initial term of the agreement
was for a period beginning April 1996 and expiring December 2008. The agreement
was renewable, at the option of U.S. One, for an extended term of 13 years
expiring December 2021. In connection with this agreement, the Company borrowed
$4,900,000 from U.S. One, of which $3,227,867 was immediately used to repay all
notes payable to Tomen America.
 
    On April 30, 1997 the Company amended this agreement which allows U.S. One
to have the exclusive right to use 888 fiber miles of the network. Additionally,
pursuant to the amended agreement, U.S. One received an option to acquire from
the Company up to 1,620 additional fiber miles upon payment of a predetermined
amount. In accordance with the amended agreement the following occurred: (i) all
interest accrued from the inception of the loan to the closing date of the
agreement was waived by U.S. One, and (ii) the $4,900,000 principal balance of
the loan was offset against the $3,530,000 scheduled payment due from U.S. One
to the Company under the amended lease agreement, and (iii) the Company paid to
U.S. One the difference of $1,370,000.
 
    In connection with the execution of the aforementioned lease and financing
agreements, the Company granted U.S. One a warrant to purchase common stock of
the Company. The warrant is exercisable for a number of shares of Class A common
stock to be determined at the Company's discretion subject to a minimum number
of 304,200 shares and maximum number of 1,825,200 shares. The per share exercise
price is to be determined pursuant to a formula, but in no event shall the
aggregate purchase price exceed $1,250,000.
 
                                      F-22
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
6. NOTES PAYABLE (CONTINUED)
    B.In October 1995, the Company initiated a private offering of $858,000 of
convertible subordinated notes. Through December 31, 1995, $783,000 of notes
were sold pursuant to this offering, and an additional $75,000 of notes were
sold during January and February of 1996. These notes were scheduled to mature
during the period October 1996 through February 1997 and bore interest at an
annual rate of 15%, payable at maturity. The notes were convertible, at the
Company's option, into shares of common stock. Concurrent with the issuance of
these notes, warrants were issued by the Company to the noteholders to purchase
522,008 shares of common stock at $2.00 per share through November 2000. In
1997, the Company repaid the outstanding balance of these notes plus all accrued
interest.
 
    In December 1996, the Company offered the noteholders warrants to purchase
428,312 shares of its common stock exercisable at $2.00 per share through
November 2000 in exchange for the extension of the due dates on the notes. All
of the noteholders accepted this offer and accordingly, the Company recorded a
non cash charge of $111,306. As of December 31, 1997, 15,212 of such warrants
have been exercised.
 
    In March 1997, in consideration for the extension of the due dates of the
notes, the Company issued warrants to the noteholders to purchase an aggregate
of 230,728 shares of common stock, exercisable at $2.00 per share through
November 2000. The Company recorded a non-cash charge of $220,036 for such
issuance. As of December 31, 1997, 7,606 of such warrants have been exercised.
 
    C. On September 24, 1996, the Company entered into a loan agreement with
Sterling Capital ("Sterling") for $550,000. The loan bore interest at 10% per
annum and matured on March 1, 1997. The loan was secured by all of the Company's
assets. As an incentive for the loan, the Company issued to Sterling warrants to
purchase 377,208 shares of common stock at an exercise price of $1.48. The
warrants are exercisable through September 1999. On May 1, 1997 the company
repaid the loan in full and all accrued interest. As of December 31, 1997,
17,144 of the warrants have been exercised.
 
    D. In August 1995, the Company initiated a $600,000 private offering of
subordinated notes. These notes were scheduled to mature in March 1996 and bore
interest at an annual rate of 15%, payable quarterly in arrears. Concurrent with
the issuance of these notes, warrants were issued by the Company to the
noteholders which were exercisable for common shares of the Company in an amount
equal to 0.7% of the outstanding shares of common stock immediately following an
initial public offering of the Company's common stock, at an exercise price
equal to 60% of the initial public offering price. These warrants are
exercisable over a three-year period beginning on the effective date of such
initial public offering. In April 1996, the Company offered the warrantholders
shares of common stock equal to 0.7% of the common stock then issued and
outstanding, in exchange for the surrender and cancellation of the outstanding
warrants, and in consideration for the extension of the maturity date of the
notes through June 30, 1996. All of the warrantholders accepted this offer and,
accordingly, the Company issued a total of 237,436 shares of the Company's
common stock. The Company recorded a noncash charge of $107,322 in connection
with such issuance. In 1996, the Company repaid $50,000 of this debt. In 1997,
the Company repaid the outstanding balance of these notes plus all accrued
interest.
 
    E. On April 18, 1995, the Company entered into a loan agreement, which was
subsequently amended, with AT&T Wireless for $500,000 bearing interest at 11%
per annum. In July 1997 the note was repaid in full. In 1995, the Company issued
to AT&T Wireless a warrant entitling the holder to purchase a total of 2,676,668
shares of the Company's common stock.
 
                                      F-23
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
6. NOTES PAYABLE (CONTINUED)
    This warrant, was canceled and replaced by a new warrant issued on February
13, 1997, to purchase 1,825,200 shares of the Company's common stock at $1.21
per share. The new warrant expires on February 13, 2000.
 
    F. On February 13, 1996, the Company entered into an investment agreement
with an individual (the "Investor") pursuant to which the company borrowed
$1,000,000 in consideration for the issuance of 12% senior subordinated
promissory notes maturing on November 1, 1996. The notes were guaranteed
personally by the Company's president. The notes were convertible at a price of
$.66 per unit for each $1,000 of principal outstanding. Each unit consisted of
the following: (i) one share of common stock, and (ii) one warrant to purchase
one share of common stock at $1.32 per share. As an inducement for entering into
the investment agreement, the Company issued to the Investor the following: (i)
1,524,348 shares of common stock, and (ii) a warrant to purchase 1,524,348
shares of common stock at $1.32 per share, exercisable through August 15, 2002.
The Company recorded noncash charges of $689,013 for such issuances.
 
    On March 19, 1996, a supplemental investment agreement was executed with the
Investor providing for an additional advance of $500,000 with the same maturity
date, interest rate, conversion rights, and guaranty features as the initial
$1,000,000 investment. This advance was subsequently repaid, along with interest
on April 16, 1996. In connection with this supplemental agreement, the Company
issued a warrant to purchase 762,172 shares of common stock at $1.32 per share,
exercisable through August 15, 2002. The Company also issued a warrant to
purchase an additional 762,172 shares of Class A common stock at $0.002 per
share exercisable through August 15, 2002. The Company recorded a noncash charge
of $250,550 for such issuance.
 
    On April 11, 1996, a memorandum of understanding was entered into between
the parties pursuant to which the warrants issued on February 13, 1996 to
purchase 1,524,348 shares at $1.32 per share and the warrants issued on March
19, 1996, to purchase 762,172 shares at $1.32 per share were surrendered by the
Investor to the Company in consideration for the issuance of 456,300 shares of
the Company's common stock.
 
    In April and July 1996, the Investor purchased 608,400 and 153,772 shares of
common stock, respectively, at $0.002 per share in connection with the exercise
of all warrants held by the Investor. Further, in accordance with the investment
agreement an additional 152,100 shares of common stock was issued to the
Investor in compliance with the anti-dilutive requirements in the agreement.
 
7. SETTLEMENT AGREEMENTS
 
    In February 1996, the Company entered into a settlement agreement with a
former officer regarding the termination of his employment. This agreement
provided for the Company to make payments to the officer totaling $1,003,000,
including interest. The former officer's services effectively terminated prior
to December 31, 1995. Accordingly, as of December 31, 1995, the Company recorded
$876,146 as a liability in accordance with the terms of the settlement
agreement.
 
    The settlement agreement also reaffirmed the option previously issued to
this former officer on May 1, 1995, which entitles the holder to purchase
831,532 shares of the Company's common stock at $0.002 per share through
February 1, 1999. In 1997 the Company repurchased and retired the warrant.
 
    On November 14, 1996, the Company amended the above referenced settlement
agreement with the former officer, whereby a consultant to the Company agreed to
purchase common stock of the
 
                                      F-24
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
7. SETTLEMENT AGREEMENTS (CONTINUED)
company from the former officer and certain of his affiliates in exchange for
$640,000 and the complete satisfaction of the aforementioned liability.
 
    On February 11, 1997, the Company entered into an agreement with a
consultant/director. Pursuant to the agreement the Company agreed to pay the
consultant/director a fee of $250,000 in full and complete payment for all
services provided to the Company by the consultant/director and for any fees or
compensation due to the consultant/director resulting from any prior agreements
with the Company, and the consultant/director agreed to release the Company from
any claims against the Company.
 
8. EQUITY TRANSACTIONS
 
STOCK ISSUED TO LEGAL COUNSEL
 
    On January 12, 1996, the Company entered into an agreement with its legal
counsel which calls for the issuance by the Company of common stock as
additional consideration for legal services provided. Pursuant to this
agreement, as amended, the Company issued a total of 1,964,420 shares of its
common stock. Management has estimated the value of the 1,964,420 shares issued
to be $907,301 and has recorded a noncash charge in connection with such
issuance.
 
PREFERRED STOCK
 
    On April 30, 1997, the Company sold an aggregate of 8,403.325 shares of
Series B convertible preferred stock, par value $0.01 per share (the "Series B
preferred stock"), to Metromedia Company and affiliates ("Metromedia") for an
aggregate purchase price of $32.5 million (the "Metromedia Investment"). Each
share of the Series B preferred stock was convertible into 1,014 shares of the
Company's common stock. On October 28, 1997, the Series B convertible preferred
shares were converted into 17,041,944 shares of Class B common stock. Further,
on October 28, 1997, a total of 157,308 shares of Class B common stock
outstanding were converted into an equivalent number of shares of Class A common
stock.
 
    A portion of the proceeds from the Metromedia Investment was used to repay
the Metromedia Loan, discussed below, and accrued interest thereon ($4,058,127),
repay other short-term indebtedness ($3,485,000), and redeem (for $2,115,000)
all of the outstanding shares of the Company's preferred stock (the "Series A
preferred stock") and related warrants.
 
    Through April 30, 1997, Metromedia loaned the Company an aggregate of
$4,000,000 (the "Metromedia Loan"). A portion of the proceeds from the
Metromedia Loan was used to purchase 2,353,880 shares of the Company's common
stock and warrants to purchase 831,532 shares of its common stock at December
31, 1997.
 
    No shares of the Company's Series A preferred stock or Series B preferred
stock remained outstanding at December 31, 1997. Both the Series A and Series B
preferred stock of the Company have been eliminated pursuant to actions by the
Board of Directors.
 
                                      F-25
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
8. EQUITY TRANSACTIONS (CONTINUED)
 
COMMON STOCK
 
    On November 3, 1997, the Company completed the initial public offering ("the
"IPO") of 36,432,000 shares of its Class A common stock, at an offering price of
$4 per share. The net proceeds to the Company from the IPO, after deducting
expenses of the IPO, were approximately $133.9 million.
 
    In addition, on October 28, 1997, a total of 38,259,760 shares of the common
stock of the Company owned by stockholders prior to the IPO were exchanged for
an equal number of shares of Class A common stock. The Company also reserved for
issuance 17,041,944 shares of Class A common stock for conversion of the Class B
common stock.
 
    On October 28, 1996, a shareholder granted to the Company's Chairman of the
Board an option to purchase 1,599,556 shares of common stock of the company for
an aggregate exercise price of $500,000. By letter dated December 3, 1996, the
option was amended to reduce the number of option shares to 1,295,356 shares.
The option was thereafter assigned by the Chairman to the Company. On February
11, 1997, the Company exercised the option by payment of $500,000.
 
    On April 15, 1996, the Company entered into a stock purchase agreement with
Vento & Company of New York, LLC ("VCNY"). Pursuant to this agreement, the
Company issued 6,084,000 shares of common stock to VCNY as consideration for
services provided by VCNY. The Company estimated the value of the stock issued
approximated $2,760,000.
 
    Concurrent with the execution of the aforementioned stock purchase
agreement, the parties entered into a consulting agreement. The term of the
agreement was from April 15, 1996 to April 15, 2001. Under the terms of the
agreement, VCNY was to provide guidance and advice with respect to the
management of the day-to-day operations of the Company's fiber optic
transmission network. In consideration for such services, the Company reimbursed
VCNY for all reasonable personnel and travel costs incurred by VCNY with respect
to the performance of these services. On October 9, 1996, the Company entered
into a settlement agreement with the Company's former chief executive officer
and VCNY regarding the termination of such officer's employment and services
provided by VCNY. The agreement provided for VCNY to deliver a total of
6,084,000 shares of common stock in exchange for payments made by the Company.
The payments were not made and the sale of the shares and the Company's
obligation to buy the shares was deemed null and void.
 
    In September 1996, the Company sold 43,736 shares of common stock to three
individuals for total proceeds of $23,500.
 
    In August 1996, the Company issued 730,080 shares of common stock for
consulting services. The Company has recorded a noncash charge of $334,800 for
such issuance.
 
    In July 1996, the Company issued 48,672 shares of common stock as
consideration for consulting services. The Company recorded a noncash charge of
$21,200 for such issuance. In addition, the Company issued 602,316 shares to
three employees for services rendered. The transaction was later rescinded and
the shares were returned to the Company.
 
    In June 1996, the Company sold a total of 152,100 shares of common stock to
two individuals for total proceeds of $100,000. Concurrent with the issuance of
these shares, warrants were issued by the Company to these shareholders
entitling the holders to purchase a total of 152,100 shares at $0.66 per share
for a three-year period.
 
                                      F-26
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
8. EQUITY TRANSACTIONS (CONTINUED)
STOCK WARRANTS
 
    In 1997, 1996 and 1995 in connection with the issuance of notes and the
extension of their due dates the Company issued warrants to the noteholders to
purchase 659,040 shares of common stock at $2.00 per share through November
2000; see Note 6.
 
    As of December 31, 1997, the Company has reserved approximately 4,704,792
shares of its common stock for exercise of warrants and contingent warrants.
 
    On December 31, 1996, the Company issued and sold to Penny Lane Partners,
L.P. ("Penny Lane") for aggregate cash consideration of $2,025,000 (i) 600,000
shares of 10% cumulative convertible preferred stock (the "Series A Preferred
Stock") bearing dividends at a rate of $0.34 per share per annum, (ii) warrants
to purchase 456,300 shares of Common Stock at an exercise price of $1.24 per
share of Common Stock (such number to be determined based on certain future
events) at an exercise price of $0.01 per share (the "Contingent Warrants"). In
March 1997, Penny Lane agreed to permit the Series A Preferred Stock and the
Contingent Warrants to be redeemed at an aggregate redemption price of
$2,115,000 (which includes accrued but unpaid dividends on the Series A
Preferred Stock) and in connection therewith the number of Penny Lane Warrants
was increased from 456,300 to 912,600.
 
    In September 1996, the Company granted 377,208 common stock purchase
warrants to Sterling at an exercise price of the lesser of $1.48 per share, the
price at which the Company shall issue its securities in the future less $1.48,
or one half the price at which the common stock of the Company is offered in an
initial public offering, exercisable on the later date of September 24, 1999 or
twelve months and 90 days after the date the warrant shares have been covered by
a registration statement. The Company has recorded a noncash charge of $13,640
for such issuance.
 
    In June 1996, the Company granted 608,400 common stock purchase warrants to
the Company's legal counsel exercisable at $0.02 per share for a period of four
years as additional consideration for legal services provided. The Company has
recorded a noncash charge of $200,000 for such issuance.
 
STOCK OPTIONS
 
    In 1997, the Company granted to certain officers, employees and directors
options to purchase up to 12,380,940 shares of its Common Stock. The options
have exercise prices between $0.49 and $1.91 per share and expire in 2007. The
Company has recorded a noncash charge of $19,218,591 for such issuance.
 
    On October 28, 1997, the Stockholders of the Company approved the Metromedia
Fiber Network, Inc. 1997 Incentive Stock Plan ("Option Plan"). The Option Plan
authorized the award of up to 4,000,000 options to acquire Class A Common Stock
of the Corporation to directors, officers and employees of the Company and
others who are deemed to provide substantial and important services to the
Company. Options to purchase 2,450,000 shares of the Company's common stock were
granted at an exercise price of $4.00 per share, the market price at the date of
grant.
 
    The Compensation Committee of the Board of Directors is responsible for
determining the type of award, when and to whom awards are granted, the number
of shares and terms of the awards and the exercise price. The options are
exercisable for a period not to exceed ten years from the date of the grant.
Vesting periods range from immediate vesting to four years.
 
                                      F-27
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
8. EQUITY TRANSACTIONS (CONTINUED)
    The following table summarizes the stock option transactions for the year
ended December 31, 1997:
 
<TABLE>
<CAPTION>
                                                                 NUMBER OF    WEIGHTED AVERAGE
                                                                  OPTIONS      EXERCISE PRICE
                                                                ------------  -----------------
<S>                                                             <C>           <C>
Granted.......................................................    14,830,940      $    1.09
Balance outstanding at December 31, 1997......................    14,830,940      $    1.09
Exercisable at December 31, 1997..............................    12,241,172
</TABLE>
 
    Pro forma information regarding net income and earnings per share is
required by Statement of Financial Standards No. 123, "Accounting for
Stock-Based Compensation" ("SAF 123"), and has been determined as if the Company
had accounted for its employees' stock options under the fair value method
provided by that Statement. The fair value of the options was estimated at the
date of grant using the Black-Scholes option pricing model with the following
assumptions for vested and non-vested options:
 
<TABLE>
<CAPTION>
                                                                             DECEMBER 31, 1997
                                                                             -----------------
<S>                                                                          <C>
Assumption
Risk-free interest yield...................................................       5.73-6.56%
Volatility factor..........................................................            .369
Dividend yield.............................................................         --
Average life...............................................................         5 years
</TABLE>
 
    The Black-Scholes options valuation model was developed for use in
estimating the fair value of traded options which have no vesting restrictions
and are fully transferable. In addition, option valuation models require the
input of highly subjective assumptions including the expected stock price
volatility. Because the Company's employee stock has characteristics
significantly different from those of traded options, and because changes in the
subjective input assumptions can materially affect the fair value estimate, in
management's option, the existing models do not necessarily provide a reliable
single measure of the fair value of its employee stock options.
 
    For purpose of pro forma disclosures, the estimated fair value of the
options is amortized to expense over the vesting period of the options. The
Company's pro forma information is as follows:
 
<TABLE>
<CAPTION>
                                                                                 DECEMBER 31,
                                                                                     1997
                                                                                --------------
<S>                                                                             <C>
Pro forma net loss applicable to common stock.................................  $  (28,043,370)
Pro forma loss per share applicable to common stock basic and diluted.........  $        (0.59)
</TABLE>
 
    The weighted average fair value of options granted during the year ended
December 31, 1997 is $1.97. The weighted average remaining contractual life of
options outstanding at December 31, 1997 is 9.4 years.
 
9. INCOME TAXES
 
    There was no provision for federal or state income taxes for the years ended
December 31, 1997, 1996 and 1995. At December 31, 1997, the Company expects to
have available approximately
 
                                      F-28
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
9. INCOME TAXES (CONTINUED)
$16,000,000 of net operating loss carryforwards, expiring in the years 2009
through 2012. The Company has recorded a full valuation allowance against the
deferred tax asset as its realization is uncertain.
 
10. RECONCILIATION OF EARNINGS PER SHARE:
 
<TABLE>
<CAPTION>
                                                                               YEAR ENDED DECEMBER 31,
                                                                    ---------------------------------------------
<S>                                                                 <C>             <C>             <C>
                                                                         1997            1996           1995
                                                                    --------------  --------------  -------------
BASIC AND DILUTED EPS
Net loss..........................................................  $  (26,259,238) $  (10,358,697) $  (4,319,101)
Deduct dividend on preferred shares...............................          76,562              --             --
                                                                    --------------  --------------  -------------
Net loss applicable to common stock...............................  $  (26,335,800) $  (10,358,697) $  (4,319,101)
                                                                    --------------  --------------  -------------
                                                                    --------------  --------------  -------------
SHARES
Weighted average number of common shares outstanding..............      47,446,912      35,858,252     24,828,940
                                                                    --------------  --------------  -------------
Net loss per common share basic and diluted.......................  $        (0.56) $        (0.29) $       (0.17)
                                                                    --------------  --------------  -------------
                                                                    --------------  --------------  -------------
</TABLE>
 
11. COMMITMENTS AND CONTINGENCIES
 
    A. The Company entered into a franchise agreement with the City of New York
on December 20, 1993, whereby the company was granted a nonexclusive franchise
to install, operate, repair, maintain and replace cable, wire, fiber or other
transmission medium and the related equipment and facilities on, over and under
the property of the City of New York. In exchange, the company is obligated to
pay franchise fees commencing on the completion date of the initial backbone of
the fiber optic cable network through December 20, 2008. In connection with the
agreement, among other requirements, the Company maintains a performance bond in
the amount of approximately $1,750,000 and has provided the City with a $500,000
letter of credit as a security fund.
 
    Franchise fees are based on a percentage of the Company's gross sales: 10%
for the first and second years, 6% for the third year and 5% for the fourth and
each year thereafter. However, during each year of the term, the franchise fee
shall be no less than $200,000.
 
    Franchise fees charged to operations in connection with this agreement
amounted to $200,000 for the years ended December 31, 1997, 1996, and 1995.
 
    B. The Company entered into a license agreement with Jersey City, New Jersey
on July 10, 1995, whereby the Company was granted a license to construct a
fiber-optic system within Jersey City. The term of this agreement continues
until written notice of termination is given by either party.
 
    C. The Company entered into a conduit occupancy agreement with Bell
Atlantic, formerly known as The New York Telephone Company, in 1993, whereby the
Company was granted a right to place and maintain cable facilities in the
conduit system of Bell Atlantic. The term of this agreement is for one year from
the date of the agreement and thereafter until three months after written notice
of termination is given by either party.
 
    The Company also has the right to place and maintain cable facilities in the
conduit system of Empire City Subway Company, Ltd., by virtue of the franchise
agreement with the City of New York.
 
                                      F-29
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
11. COMMITMENTS AND CONTINGENCIES (CONTINUED)
    Occupancy fees charged to operations in connection with this agreement were
approximately $120,000 and $152,000 for the years ending December 31, 1997 and
1996, respectively.
 
    D. The Company leases several office facilities under operating leases which
expire at various times through March 31, 2010.
 
    Rent expense charged to operations was approximately $268,000, $158,000 and
$148,000 for the years ended December 31, 1997, 1996 and 1995, respectively.
 
    E. On June 1, 1995, the Company entered into two lease agreements with the
Port Authority of New York and New Jersey, whereby the Company was granted a
nonexclusive right to lease two ducts in the North and South tubes of the
Holland Tunnel to install, maintain, operate and provide telecommunications
equipment for its customers. The term of these agreements is for ten years
through June 1, 2005.
 
    Lease expense charged to operations in connection with these leases was
approximately $112,000, $107,000 and $63,000 for the years ending December 31,
1997, 1996 and 1995, respectively.
 
    F. On August 11, 1995, the Company entered into a service agreement with an
unrelated party, for the maintenance of the Company's telecommunications
equipment located in Jersey City. The term of this agreement is for one year
with an option to renew this agreement annually for up to five consecutive one
year renewal terms. Service fees charge to operations in connections with this
agreement was approximately $24,000 in 1997.
 
    G. On November 17, 1997 the Company entered into an agreement with a
telecommunication company (the "Seller") to purchase conduit and associated
improvements (the "Conduit System") within a multiple conduit system being
constructed by the Seller, in the counties of Philadelphia and Montgomery,
Pennsylvania.
 
    The purchase price for the conduit system is $546,940 which is payable in
installments. Upon the acceptance of the multiple Conduit System by the Company
the Seller will grant, bargain, sell, assign, transfer, convey and set over all
right, title, and interest in the Conduit System.
 
    H. On December 1, 1997, the Company entered into an Agreement which provides
the Company with the right-of-way to construct, install, operate and maintain
two innerducts containing fiber optic cable in a tunnel which connects New York
City and Secaucus, New Jersey.
 
    The initial term of this agreement is for five years with an option to renew
and extend the agreement for five consecutive renewal terms of five years. The
annual rental fee is $151,199 for the first contract year. On each anniversary
of the effective date the annual rental fee shall be adjusted to reflect the
increases in the CPI of the previous year.
 
    I. On December 5, 1997 the Company entered into an agreement with a utility
company to purchase conduit (existing and future) for the installation of fiber
optic cable used exclusively to provide telecommunication services in the city
of Chicago. The purchase price for the existing conduit is $1.3 million, of
which $130,000 was paid in December 1997 with the remainder payable during the
first quarter of 1998.
 
                                      F-30
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
11. COMMITMENTS AND CONTINGENCIES (CONTINUED)
    J. Approximate minimum annual franchise, license, lease and service fees and
conduit payments under the aforementioned agreement are as follows:
 
<TABLE>
<S>                                                              <C>
For the year ended December 31:
1998...........................................................  $3,095,604
1999...........................................................   1,612,782
2000...........................................................   1,614,689
2001...........................................................   1,601,907
2002...........................................................   1,597,535
Thereafter.....................................................   5,374,572
                                                                 ----------
                                                                 $14,897,089
                                                                 ----------
                                                                 ----------
</TABLE>
 
    K. In February 1997, a former investment advisor to the Company asserted a
claim against the Company in the amount of $305,731 pursuant to an agreement
made on June 27, 1995, for the payment of certain fees and expenses. In
September 1997, the Company paid the former investment advisor $250,000 in full
settlement of such claim plus any and all related expenses.
 
    L. On or about April 18, 1997, Howard Katz, Realprop Capital Corporation and
Evelyn Katz commenced an action against, among others, the Company, Stephen A.
Garofalo, Peter Sahagen and Peter Silverman in the United States District Court
for the Southern District Court of New York captioned Katz, et al. v. National
Fiber Network, Inc., et al., No. 97 Civ. 2764 (JGK) (the "Katz Litigation"). On
May 28, 1997, the plaintiffs filed an amended complaint and on September 15,
1997, the plaintiffs filed a second amended complaint. The complaint as amended
alleges causes of action for, among other things, common law fraud, violations
of section 10(b) of the Securities Exchange Act of 1934 and Rule 10b-5
promulgated thereunder, breach of fiduciary duty and negligent misrepresentation
for alleged misrepresentations and omissions made in connection with the
repurchase of a right to purchase an aggregate of 1,058,524 shares of Class A
common stock of the Company, which class of shares was authorized in October
1997, and an option to purchase warrants for the purchase of 831,552 shares of
Class A common stock. The amended complaint also contains allegations of
corporate waste against the Company and Stephen A. Garofalo. Plaintiffs seek,
among other things, compensatory damages of not less than $12 million, punitive
damages in the amount of $100 million and, in the alternative, rescission of the
purchase of the common stock and warrants by the Company. On October 31, 1997,
all defendants moved to dismiss the amended complaint. The motions were fully
briefed as of December 12, 1997. The Company intends to vigorously defend itself
against these allegations based on its belief that the Company acted
appropriately in connection with the matters at issue in this litigation. No
assurance can be made, though, that the Company will not determine that the
advantages of entering into a settlement outweigh the risk and expense of
protracted litigation or that ultimately the Company will be successful in its
defense of the allegations. If the Company is unsuccessful in its defense of the
allegations, an award of the magnitude being sought by the plaintiffs in the
Katz Litigation would have a material adverse effect on the Company's financial
condition or results of operations.
 
    M. On or about October 20, 1997, Vento & Company of New York, LLC ("VCNY")
commenced an action against the Company, Stephen A. Garofalo, Peter Silverman,
the law firm of Silverman, Collura, Chernis & Balzano, P.C., Peter Sahagen,
Sahagen Consulting Group of Florida (collectively, the "Sahagen Defendants") and
Robert Kramer, Birdie Capital Corp, Lawrence Black, Sterling Capital
 
                                      F-31
<PAGE>
                 METROMEDIA FIBER NETWORK, INC. & SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
11. COMMITMENTS AND CONTINGENCIES (CONTINUED)
LLC, Penrush Limited, Needham Capital Group, Arthur Asch, Michael Asch and
Ronald Kuzon (the "Kramer Defendants") in the United States District Court for
the Southern District of New York (No. 97 CIV 7751) (the "VCNY Litigation"). The
complaint alleges causes of action for, among other things, violation of Section
10(b) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated
thereunder, fraud and fraudulent concealment, breach of fiduciary duty and
negligent misrepresentation and omission made in connection with the sale by
VCNY of 2,737,800 shares of Class A common stock to Peter Sahagen and the Kramer
Defendants on January 13, 1997 (the "VCNY Sale"). The complaint also alleges a
cause of action for declaratory judgment asserting that certain "piggyback"
registration rights are applicable to shares of the Company's Class A common
stock which VCNY owns (or which may be rescinded to VCNY pursuant to its
requested remedies). The complaint further requests a declaratory judgement that
a stockholders' agreement between the Company, Stephen A. Garofalo and VCNY be
declared operative, which agreement indirectly required VCNY, through designated
directors, to approve significant transactions, and, accordingly, the Metromedia
Loan and the Metromedia Investment should be rescinded and Mr. Vento should be
reappointed as Chief Executive Officer of the Company. The Company believes,
among other things, that the stockholder's agreement to which Mr. Vento was a
party had terminated and, as a result, Mr. Vento had no such rights to approve
the Metromedia Investment or the Metromedia Loan or to remain as Chief Executive
Officer of the Company. Plaintiff seeks, among other things, (i) rescission of
the VCNY Sale, or alternatively, damages in an amount not presently
ascertainable, but believed to be in the excess of $36 million, together with
interest thereon, (ii) punitive damages in the amount of $50 million, and (iii)
the declaratory judgements discussed above. The Company intends to vigorously
defend itself against these allegations based on its belief that it acted
appropriately in connection with the matters at issue in this litigation.
However, no assurance can be made that the Company will not determine that the
advantages of entering into a settlement outweigh the risk and expense of
protracted litigation or that ultimately the Company will be successful in its
defense of the allegations. If the Company is unsuccessful in its defense of the
allegations, an award of the magnitude being sought by the plaintiffs in the
VCNY Litigation would have a material adverse effect on the Company's financial
condition or results of operations.
 
                                      F-32
<PAGE>
                                                                      APPENDIX A
 
                                    GLOSSARY
 
<TABLE>
<S>                               <C>
Access Charge...................  The fees paid by long distance carriers to LECs for
                                  originating and terminating long distance calls on the
                                  LECs' local networks.
 
Analog Transmission.............  A way of sending voice, video and data signals
                                  electronically in which the transmitted signal is
                                  analogous to the original signal.
 
ATM (Asynchronous Transfer
  Mode).........................  An information transfer standard that is one of a general
                                  class of packet technologies that relay traffic by way of
                                  an address contained within the first five bytes of a
                                  standard fifty-three-byte-long packet or cell. The ATM
                                  format can be used by many different information systems,
                                  including local area networks to deliver traffic at
                                  varying rates, permitting a mix of voice, data and video
                                  (multimedia).
 
Backbone........................  The backbone is the part of the telecommunications network
                                  which carries the most traffic. It is the through-portion
                                  of a transmission network, as opposed to spurs which
                                  branch off the through-potions.
 
Bandwidth.......................  The range of analog frequencies or digital signals that
                                  can be passed through a transmission medium, such as fiber
                                  optic cable. The greater the bandwidth, the greater the
                                  information carrying capacity. Bandwidth is measured in
                                  Hertz (analog) or Bits Per Second (digital).
 
Bit.............................  A contraction of the term Binary Digit, it is the basic
                                  unit in data communications. Bits are typically
                                  represented by ones or zeros.
 
Capacity........................  The information carrying ability of a telecommunications
                                  facility.
 
Central Office..................  Telephone company facility where subscribers' lines are
                                  joined to switching equipment for connecting other
                                  subscribers to each other, locally and long distance.
 
Channel.........................  A path of communication either electrical or
                                  electromagnetic, between two or more points. Also called a
                                  circuit, facility, line, link, or path.
 
CLEC (Competitive Local Exchange
  Carrier)......................  A company that competes with local exchange carriers in
                                  the local services market.
 
Coaxial Cable...................  A cable composed of an insulated central conducting wire
                                  wrapped in another cylindrical conducting wire. It is
                                  typically used to carry high-speed data.
 
Collocation.....................  Collocation refers to the physical location of a
                                  telecommunication carrier's switch in the ILECs premises
                                  to facilitate the interconnection of their respective
                                  switching equipment.
</TABLE>
 
                                      A-1
<PAGE>
<TABLE>
<S>                               <C>
Common Carrier..................  A government defined group of private companies offering
                                  telecommunications services or facilities to the general
                                  public on a non-discriminatory basis.
 
Conduit.........................  A pipe, usually made of metal, ceramic or plastic, that
                                  protects buried cables.
 
Dark Fiber......................  Fiber optic cable without any of the electronic or
                                  optronic equipment necessary to use the fiber for
                                  transmission.
 
Digital.........................  Describes a method of storing, processing and transmitting
                                  information through the use of distinct electronic or
                                  optical pulses that represent the binary digits 0 and 1.
                                  Digital transmission/switching technologies employ a
                                  sequence of discrete, distinct pulses to represent
                                  information, as opposed to the continuously variable
                                  analog signal.
 
DS-3............................  DS is the standard telecommunications industry designation
                                  of a hierarchy of digital signal speeds used to classify
                                  capacities of lines and trunks. DS-3 service has a bit
                                  rate of approximately 45 megabits per second and can
                                  transmit roughly 672 simultaneous voice conversations.
 
FCC (Federal Communications
  Commission)...................  Regulatory body established pursuant to the Communications
                                  Act of 1934; it has the authority to regulate all
                                  interstate communications originating in the United
                                  States.
 
Fiber Miles.....................  The number of strands of fiber in a length of fiber optic
                                  cable multiplied by the length of the cable in miles.
 
Fiber Optics....................  A technology in which light is used to transport
                                  information from one point to another. Fiber optic cables
                                  are thin filaments of glass through which light beams are
                                  transmitted over long distances carrying enormous amounts
                                  of data. Modulating light on thin strands of glass
                                  produces major benefits in high-bandwidth, relatively low
                                  cost, low power consumption, small space needs, total
                                  insensitivity to electromagnetic interference and great
                                  insensitivity to being bugged.
 
Frame Relay.....................  A high-speed, data-packet switching service used to
                                  transmit data between computers. Frame Relay supports data
                                  units of variable lengths at access speeds ranging from 56
                                  kilobits per second to 1.5 megabits per second. This
                                  service is well-suited for connecting local area networks,
                                  but is not presently well-suited for voice and video
                                  applications due to the variable delays which can occur.
                                  Frame Relay was designed to operate at high speeds on
                                  modern fiber optic networks.
 
ILEC (Incumbent Local Exchange
  Carrier)......................  A company historically providing local telephone service.
                                  Often refers to one of the Regional Bell Operating
                                  Companies (RBOCs). Often referred to as "LEC" (Local
                                  Exchange Carrier).
 
ISP (Internet Service
  Provider).....................  A vendor who provides direct access to the Internet. The
                                  ISP also usually provides a core group of Internet
                                  utilities and services like E-mail and News Group Readers.
</TABLE>
 
                                      A-2
<PAGE>
<TABLE>
<S>                               <C>
IXC (Interexchange Carrier).....  Literally, a company providing services which cross local
                                  exchange boundaries. Refers to long distance providers.
 
LAN (Local Area Network)........  A short distance data communications network (typically
                                  within a building or campus) used to link together
                                  computers and peripheral devices (such as printers) under
                                  some form of standard control.
 
Lit Fiber.......................  Fiber activated or equipped with the requisite electronic
                                  and optronic equipment necessary to use the fiber for
                                  transmission.
 
Metered Telecommunications
  Service.......................  Service provided by phone companies where charges are
                                  levied based on use, as opposed to unmetered service,
                                  where charges are levied according to a flat, fixed rate.
 
OC-3, OC-12, OC-48 and OC-192...  OC, or Optical Carrier, is a measure of a SONET
                                  transmission optical carrier level. The number following
                                  the OC designation is equal to the corresponding number of
                                  DS-3s. (e.g. OC-192 is equal to 192 DS-3s).
 
POP (Point of Presence).........  The place where an IXC terminates an end user's long
                                  distance lines just before those lines are connected to
                                  the end-user's local phone company's lines or the
                                  end-user's own direct hookup.
 
Private Line....................  A direct channel specifically dedicated to a customer's
                                  use between specified points.
 
RBOCs (Regional Bell Operating
  Companies)....................  The seven local telephone companies (formerly part of
                                  AT&T) established as a result of the AT&T Divestiture
                                  Decree.
 
Regeneration/Amplifier..........  Devices which automatically re-transmit or boost signals
                                  on an out-bound circuit.
 
Route Miles.....................  The number of miles spanned by fiber optic cable
                                  calculated without including physically overlapping
                                  segments of cable.
 
SONET (Synchronous Optical
  Network)......................  An electronics and network architecture for variable
                                  bandwidth products which enables transmission of voice,
                                  data and video (multimedia) at very high speeds. SONET
                                  ring architecture provides for virtually instantaneous
                                  restoration of service in the event of a fiber cut by
                                  automatically rerouting traffic in the opposite direction
                                  around the ring.
 
Switch..........................  A device which opens or closes circuits, completes or
                                  breaks an electrical path, or selects paths or circuits.
                                  Switching is the process of interconnecting circuits to
                                  form a transmission path between users. It also captures
                                  information for billing purposes.
 
Tier I..........................  The top 15 cities in the United States based on
                                  population.
 
Unbundled.......................  Services, programs, software and training sold separately
                                  from the hardware.
 
Video Services..................  The provision of video over a channel. Akin to voice dial
                                  tone.
 
Wireless........................  A communications system that operates without wires.
                                  Cellular service is an example.
</TABLE>
 
                                      A-3
<PAGE>
                         METROMEDIA FIBER NETWORK, INC.
                     OFFER TO EXCHANGE $650,000,000 OF ITS
                      10% SERIES B SENIOR NOTES DUE 2008,
              WHICH HAVE BEEN REGISTERED UNDER THE SECURITIES ACT,
                      FOR $650,000,000 OF ITS OUTSTANDING
                       10% SERIES A SENIOR NOTES DUE 2008
 
                             ---------------------
 
                                   PROSPECTUS
 
                                          , 1999
 
                             ---------------------
 
No person has been authorized to give any information or to make any
representations other than those contained in this Prospectus, and, if given or
made, such information or representations must not be relied upon as having been
authorized. This Prospectus does not constitute an offer to sell or the
solicitation of an offer to buy any securities other than the securities to
which it relates or an offer to sell or the solicitation of an offer to buy such
securities in any circumstances in which such offer or solicitation is unlawful.
Neither the delivery of this Prospectus nor any sale made hereunder shall, under
any circumstances, create any implication that there has been no change in the
affairs of the Company since the date hereof or that the information contained
herein is correct as of any time subsequent to its date.
<PAGE>
                                    PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 20. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
    Section 145 of the Delaware General Corporation Law provides that a Delaware
corporation may indemnify any person who was or is a party or is threatened to
be made a party, to any threatened, pending or completed action, suit or
proceeding, whether civil, criminal, administrative or investigative (a
"proceeding") (other than an action by or in the right of the corporation) by
reason of the fact that such person is or was a director, officer, employee or
agent of the corporation, or is or was serving at the request of the corporation
as a director, officer, employee or agent of another corporation, partnership,
joint venture, trust or other enterprise, against expenses (including attorneys'
fees), judgments, fines and amounts paid in settlement actually and reasonably
incurred by such person in connection with such action, suit or proceeding if
such person acted in good faith and in a manner such person reasonably believed
to be in or not opposed to the best interests of the corporation, and, with
respect to any criminal action or proceeding, had no reasonable cause to believe
his or her conduct was unlawful. A Delaware corporation may indemnify any person
under such section in connection with a proceeding by or in the right of the
corporation to procure judgment in its favor, as provided in the preceding
sentence, against expenses (including attorneys' fees) actually and reasonably
incurred by him or her in connection with the defense or settlement of such
action, except that no indemnification shall be made in respect thereof unless,
and then only to the extent that, a court of competent jurisdiction shall
determine upon application that such person is fairly and reasonably entitled to
indemnity for such expenses as the court shall deem proper. A Delaware
corporation must indemnify any person who was successful on the merits or
otherwise in defense of any action, suit or proceeding or in defense of any
claim, issue or matter in any proceeding, by reason of the fact that such person
is or was a director, officer, employee r agent of the corporation or is or was
serving at the request of the corporation as a director, officer, employee or
agent of another corporation, partnership, joint venture, trust or other
enterprise, against expenses (including attorneys' fees) actually and reasonably
incurred by such person in connection therewith. A Delaware corporation may pay
for the expenses (including attorneys' fees) incurred by an officer or director
in defending a proceeding in advance of the final disposition upon receipt of an
undertaking by or on behalf of such director or officer to repay such amount if
it shall ultimately be determined that he or she is not entitled to be
indemnified by the corporation.
 
   
    Metromedia Fiber Network's Amended and Restated Certificate of Incorporation
provides that Metromedia Fiber Network will indemnify any person, including
persons who are not directors or officers of Metromedia Fiber Network, to the
extent permitted by Section 145 of the Delaware General Corporation Law.
    
 
   
    Section 102(b) (7) of the Delaware General Corporation Law provides that a
Delaware corporation may in its articles of incorporation eliminate or limit the
personal liability of a director to the corporation or its stockholders for
monetary damages for breach of fiduciary duty as a director except for
liability: for any breach of the director's duty of loyalty to the corporation
or its stockholder; for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law; under Section 174
(pertaining to certain prohibited acts including unlawful payment of dividends
or unlawful purchase or redemption of the corporation's capital stock); or for
any transaction from which the director derived an improper personal benefit.
Metromedia Fiber Network's Amended and Restated Certificate of Incorporation
eliminates the liability of directors for monetary damages for breach of
fiduciary duty as a director, except for liability (i) for any breach of the
director's duty of loyalty to Metromedia Fiber Network or its stockholders, (ii)
for acts or omissions not in good faith or which involve intentional misconduct
or a knowing violation of law, (iii) under Section 174 of the Delaware General
Corporation Law, or (iv) for any transaction from which the director derived an
improper personal benefit, and provides that if the Delaware General Corporation
Law is amended to
    
 
                                      II-1
<PAGE>
   
authorize corporate action further eliminating or limiting the personal
liability of directors, then the liability of a director of Metromedia Fiber
Network shall be eliminated or limited to the fullest extent permitted by the
Delaware General Corporation Law, as so amended.
    
 
   
    The Delaware General Corporation Law permits the purchase of insurance on
behalf of directors and officers against any liability asserted against
directors and officers and incurred by such persons in such capacity, or arising
out of their status as such, whether or not the corporation would have the power
to indemnify officers and directors against such liability. Metromedia Fiber
Network's Amended and Restated Certificate of Incorporation allows Metromedia
Fiber Network to maintain insurance, at its expense, to protect itself and any
director, officer, employee or agent of Metromedia Fiber Network or another
corporation, partnership, joint venture, trust or other enterprise against any
expense, liability or loss, whether or not Metromedia Fiber Network would have
the power to indemnify such person against such expense, liability or loss under
the Delaware General Corporation Law. Metromedia Fiber Network has obtained
liability coverage, which includes coverage to reimburse Metromedia Fiber
Network for amounts required or permitted by law to be paid to indemnify
directors and officers.
    
 
   
    Metromedia Fiber Network's Amended and Restated Certificate of Incorporation
limits the liability of directors thereof to the extent permitted by Section
102(b)(7) of the Delaware General Corporation Law.
    
 
   
    Metromedia Fiber Network's Indenture, dated November 25, 1998, provides that
no past, present or future director, officer, employee, incorporator, agent or
shareholder of Metromedia Fiber Network's, as such, shall have any liability for
any obligations of Metromedia Fiber Network under the notes, the indenture or
for any claim based on, in respect of, or by reason of, such obligations or
their creation.
    
 
   
    Metromedia Fiber Network's Purchase Agreement, dated November 20, 1998,
provides that each Initial Purchaser of the initial notes severally and not
jointly agrees to indemnify and hold harmless Metromedia Fiber Network, each of
its directors, officers, employees, agents and each person who controls
Metromedia Fiber Network within the meaning of the Securities Act or the
Securities Exchange Act of 1934, against any and all losses, claims, damages or
liabilities, joint or several, to which they or any of them may become subject
under the Securities Act, the Securities Exchange Act of 1934 or other federal
or state statutory law or regulation, at common law or otherwise, insofar as
such losses, claims, damages or liabilities (or actions in respect thereof)
arise out of or are based upon any untrue statement or alleged untrue statement
of a material fact contained in the preliminary memorandum, the final memorandum
for the initial notes (or in any supplement or amendment thereto) or any
information provided by Metromedia Fiber Network to any holder or prospective
purchaser of notes pursuant to Section 5(h), or in any amendment thereof or
supplement thereto, or arise out of or are based upon the omission or alleged
omission to state therein, in the light of the circumstances under which they
were made, not misleading, and agrees to reimburse each such indemnified party,
as incurred, for any legal or other expenses reasonably incurred by them in
connection with investigating or defending any such loss, claim, damage,
liability or action, but only with reference to written information relating to
such Initial Purchaser furnished to Metromedia Fiber Network by or on behalf of
such Initial Purchaser through the Representatives specifically for inclusion in
the preliminary memorandum or the final memorandum (or in any amendment or
supplement thereto). This indemnity will be in addition to any liability which
any Initial Purchaser may otherwise have. The indemnity agreement will be in
addition to any liability which any initial purchaser of the Initial Notes may
otherwise have.
    
 
   
    Metromedia Fiber Network's Registration Rights Agreement, dated November 25,
1998, provides that each holder of notes, covered by any registration statement
(including each Initial Purchaser and each exchanging dealer) severally agrees
to indemnify and hold harmless (i) Metromedia Fiber Network, (ii) each of its
directors, (iii) each of its officers, employees and agents and (iv) each Person
    
 
                                      II-2
<PAGE>
   
who controls Metromedia Fiber Network within the meaning of either the
Securities Act or the Securities Exchange Act of 1934 against any and all
losses, claims, damages or liabilities to which they may become subject under
the Securities Act, the Securities Exchange Act of 1934 or other federal or
state statutory law or regulation, at common law or otherwise, insofar as such
losses, claims, damages or liabilities arise out of or are based upon any untrue
statement or alleged untrue statement of a material fact contained in the
registration statement or any omission or alleged omission to state therein a
material fact required to be stated or necessary to make the statements therein
not misleading, but only with reference to written information relating to such
holder furnished to Metromedia Fiber Network by or on behalf of such holder
specifically for inclusion in the documents referred to in the foregoing
indemnity. This indemnity agreement will be in addition to any liability which
any such holder may otherwise have. The indemnity will be in addition to any
liability which any such holder may otherwise have.
    
 
   
    Metromedia Fiber Network's Underwriting Agreement, dated October 28, 1997,
provides that each U.S. Underwriter (as defined in the Underwriting Agreement)
severally agrees to indemnify and hold harmless Metromedia Fiber Network, each
of its directors, each of its officers who signs the Registration Statement, and
each person who controls Metromedia Fiber Network within the meaning of either
the Securities Act or the Securities Exchange Act of 1934, but only with
reference to written information relating to such U.S. Underwriter furnished to
Metromedia Fiber Network by or on behalf of such U.S. Underwriter through the
U.S. Representatives specifically for inclusion in the documents referred to in
the foregoing indemnity. The indemnity agreement will be in addition to any
liability which any U.S. Underwriter may otherwise have.
    
 
   
    Metromedia Fiber Network's Directors' and Officers' liability insurance
policy is designed to reimburse Metromedia Fiber Network for payments made by it
pursuant to the foregoing indemnification. Such policy has aggregate coverage of
$25 million.
    
 
                                      II-3
<PAGE>
ITEM 21. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.
 
(A) EXHIBITS
 
   
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                                   DESCRIPTION
- -----------  --------------------------------------------------------------------------------------------------------
<S>          <C>
 
       3.1   Form of Amended and Restated Certificate of Incorporation of Metromedia Fiber Network, Inc.
             (incorporated by reference to the Company's Registration Statement on Form S-1 (Registration No.
             333-33653)).
 
       3.2   Form of Amended and Restated Bylaws of Metromedia Fiber Network, Inc. (incorporated by reference to the
             Company's Registration Statement on Form S-1 (Registration No. 333-33653)).
 
       4.1   Specimen Class A Common Stock Certificate of Metromedia Fiber Network, Inc. (incorporated by reference
             to the Company's Registration Statement on Form S-1 (Registration No. 333-33653)).
 
       4.2   Indenture, dated as of November 25, 1998, between Metromedia Fiber Network, Inc. and IBJ Whitehall Bank
             & Trust Company (formerly IBJ Schroder Bank & Trust Company).
 
       4.3   Form of 10% Series A Senior Notes due 2008 of Metromedia Fiber Network, Inc.
 
      4.4*   Form of 10% Series B Senior Notes due 2008 of Metromedia Fiber Network, Inc.
 
       5.1   Opinion of Paul, Weiss, Rifkind, Wharton & Garrison regarding the legality of the Exchange Notes.
 
       8.1   Opinion of Paul, Weiss, Rifkind, Wharton & Garrison regarding certain United States federal income tax
             matters.
 
      10.1   Form of Metromedia Fiber Network, Inc. 1997 Incentive Stock Plan (incorporated by reference to the
             Company's Registration Statement on Form S-1 (Registration No. 333-33653)).
 
      10.2   Employment Agreement by and between National Fiber Network, Inc. and Stephen A. Garofalo, dated as of
             February 26, 1997 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
 
      10.3   Employment Agreement by and between National Fiber Network, Inc. and Howard Finkelstein, dated as of
             April 30, 1997 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
 
      10.4   Agreement dated as of April 30, 1997, as amended by a Modification Agreement dated as of October, 1997
             by and among Metromedia Company, Stuart Subotnick, Arnold Wadler, Silvia Kessel, Stephen A. Garofalo and
             National Fiber Network, Inc. (incorporated by reference to the Company's Registration Statement on Form
             S-1 (Registration No. 333-33653)).
 
      10.5   Franchise Agreement between The City of New York and National Fiber Network, Inc., dated as of December
             20, 1993 (incorporated by reference to the Company's Registration Statement on Form S-1 (Registration
             No. 333-33653)).
 
      10.6   Conduit Occupancy Agreement by and between New York Telephone Company and National Fiber Network, Inc.,
             dated as of May 1993 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
</TABLE>
    
 
                                      II-4
<PAGE>
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                                   DESCRIPTION
- -----------  --------------------------------------------------------------------------------------------------------
<S>          <C>
      10.7   Consulting Agreement between National Fiber Network and Realprop Capital Corporation, dated as of
             February 1, 1996 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
 
      10.8   Letter Agreement from National Fiber Network, Inc. to Peter Sahagen, dated February 11, 1997
             (incorporated by reference to the Company's Registration Statement on Form S-1 (Registration No.
             333-33653)).
 
      10.9   Office Lease by and between National Fiber Network, Inc. and 110 East 42nd Street Associates, dated as
             of March 19, 1997 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
 
     10.10   Office Lease by and between National Fiber Network, Inc. and 110 East 42nd Street, dated as of June 1997
             (incorporated by reference to the Company's Registration Statement on Form S-1 (Registration No.
             333-33653)).
 
     10.11   Trademark License Agreement by and between Metromedia Company and Metromedia Fiber Network, Inc., dated
             as of August 14, 1997 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
 
     10.12   Fiber Optic Use Agreement between National Fiber Network, Inc. and NextLink New York, L.L.C., dated as
             of June 3, 1997 (portions of this exhibit are subject to a request to the Securities and Exchange
             Commission for confidential treatment, and omitted material has been separately filed with the
             Securities and Exchange Commission) (incorporated by reference to the Company's Registration Statement
             on Form S-1 (Registration No. 333-33653)).
 
     10.13   Amended and Restated Agreement for the Provision of a Fiber Optic Transmission Network, dated as of the
             Effective Date by and between US ONE Communications of New York, Inc. and National Fiber Network, Inc.
             (portions of this exhibit are subject to a request to the Securities and Exchange Commission for
             confidential treatment, and omitted material has been separately filed with the Securities and Exchange
             Commission) (incorporated by reference to the Company's Registration Statement on Form S-1 (Registration
             No. 333-33653)).
 
     10.14   Fiber Lease and Innerduct Use Agreement by and between Metromedia Fiber Network, Inc. and NextLink
             Communications, Inc., dated as of February 23, 1998 (portions of this exhibit are subject to a request
             to the Securities and Exchange Commission for confidential treatment, and omitted material has been
             separately filed with the Securities and Exchange Commission) (incorporated by reference to the
             Company's Annual Report on Form 10-K (File No.000-2369)).
 
     10.15   Amendment No. 1 to Fiber Lease and Innerduct Use Agreement by and between Metromedia Fiber Network, Inc.
             and NextLink Communications, Inc., made and entered into as of March 4, 1998 (portions of this exhibit
             are subject to a request to the Securities and Exchange Commission for confidential treatment, and
             omitted material has been separately filed with the Securities and Exchange Commission) (incorporated by
             reference to the Company's Annual Report on Form 10-K (File No.000-2369)).
 
     10.16   Agreement of Lease by and between Connecticut General Life Insurance Company and Metromedia Fiber
             Network Services, Inc., dated as of March 9, 1998 (incorporated by reference to the Company's Annual
             Report on Form 10-K (File No. 000-2369)).
</TABLE>
 
                                      II-5
<PAGE>
   
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                                   DESCRIPTION
- -----------  --------------------------------------------------------------------------------------------------------
<S>          <C>
     10.17   Purchase Agreement, dated November 20, 1998 among Metromedia Fiber Network, Inc., Salomon Smith Barney,
             Inc., Chase Securities, Inc., Deutsche Bank Securities Inc. and Donaldson Lufkin & Jenrette Securities
             Corporation.
 
     10.18   Registration Rights Agreement, dated as of November 25, 1998 among Metromedia Fiber Network, Inc.,
             Salomon Smith Barney, Inc., Chase Securities, Inc., Deutsche Bank Securities Inc. and Donaldson Lufkin &
             Jenrette Securities Corporation.
 
     10.19   Security Agreement, dated as of November 25, 1998, between Metromedia Fiber Network, Inc. and IBJ
             Schroder Bank & Trust Company.
 
    10.20*   Employment Agreement by and between Metromedia Fiber Network, Inc. and Vincent A. Galluccio, dated as of
             August 31, 1998.
 
    10.21*   Employment Agreement by and between Metromedia Fiber Network, Inc. and Gerard Benedetto, dated as of
             August 31, 1998.
 
    10.22*   Employment Agreement by and between Metromedia Fiber Network, Inc. and Nicholas M. Tanzi, dated as of
             August 31, 1998.
 
     12.1*   Statement Regarding Computation of Ratios.
 
      21.1   List of Subsidiaries of Metromedia Fiber Network, Inc.
 
     23.1*   Consent of Ernst & Young LLP.
 
     23.2*   Consent of M.R. Weiser & Co. LLP.
 
      23.3   Consent of Paul, Weiss, Rifkind, Wharton & Garrison (included in the opinion filed as Exhibit 5.1 to
             this Registration Statement).
 
      23.4   Consent of Paul, Weiss, Rifkind, Wharton & Garrison (included in the opinion filed as Exhibit 8.1 to
             this Registration Statement).
 
      24.1   Power of Attorney from officers and directors.
 
      25.1   Statement of Eligibility of IBJ Whitehall Bank & Trust Company as Trustee, on Form T-1.
 
     99.1*   Form of Exchange Agency Agreement.
 
     99.2*   Form of Letter of Transmittal.
 
     99.3*   Form of Notice of Guaranteed Delivery.
</TABLE>
    
 
- ------------------------
 
   
*   Filed herewith.
    
 
(B) FINANCIAL DATA SCHEDULES.
 
    None.
 
ITEM 22. UNDERTAKINGS.
 
    Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
registrant pursuant to the provisions described under Item 20, or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or
 
                                      II-6
<PAGE>
controlling person of the registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act and will be governed by the final adjudication of such issue.
 
    The undersigned registrant hereby undertakes:
 
    (1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this Registration Statement:
 
        (i) To include any prospectus required by Section 10(a)(3) of the
    Securities Act of 1933;
 
        (ii) To reflect in the prospectus any facts or events arising after the
    effective date of this Registration Statement (or the most recent
    post-effective amendment thereof) which, individually or in the aggregate,
    represent a fundamental change in the information set forth in this
    Registration Statement. Notwithstanding the foregoing, any increase or
    decrease in volume of securities offered (if the total dollar value of
    securities offered would not exceed that which was registered) and any
    deviation from the low or high end of the estimated maximum offering range
    may be reflected in the form of prospectus filed with the Securities and
    Exchange Commission pursuant to Rule 424(b) if, in the aggregate, the
    changes in volume and price represent no more than a 20% change in the
    maximum aggregate offering price set forth in the "Calculation of
    Registration Fee" table in the effective Registration Statement;
 
        (iii) To include any material information with respect to the plan of
    distribution not previously disclosed in this Registration Statement or any
    material change to such information in this Registration Statement;
 
    (2) That, for the purpose of determining any liability under the Securities
Act of 1933, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof; and
 
    (3) To remove from registration by means of a post-effective amendment any
of the securities being registered which remain unsold at the termination of the
offering.
 
    The undersigned Registrant hereby undertakes to deliver or cause to be
delivered with the prospectus, to each person to whom the prospectus is sent or
given, the latest annual report to security holders that is incorporated by
reference in the prospectus and furnished pursuant to and meeting the
requirements of Rule 14a-3 or Rule 14c-3 under the Securities Exchange Act of
1934; and, where interim financial information required to be presented by
Article 3 of Regulation S-X are not set forth in the prospectus, to deliver, or
cause to be delivered to each person to whom the prospectus is sent or given,
the latest quarterly report that is specifically incorporated by reference in
the prospectus to provide such interim financial information.
 
    The undersigned Registrant hereby undertakes that for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to section 13(a) or section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.
 
    The undersigned registrant hereby undertakes as follows:
 
                                      II-7
<PAGE>
    (a) That prior to any public reoffering of the securities registered
hereunder through use of a prospectus which is part of this registration
statement, by any person or party who is deemed to be an underwriter within the
meaning of Rule 145(c) the issuer undertakes that such reoffering prospectus
will contain the information called for by the applicable registration form with
respect to reofferings by persons who may be deemed underwriters, in addition to
the information called for by the other Items of the applicable form.
 
    (b) Every prospectus (i) that is filed pursuant to the paragraph immediately
preceding, or (ii) that purports to meet the requirements of section 10(a)(3) of
the Act and is used in connection with an offering of securities subject to Rule
415, will be filed as a part of an amendment to the registration statement and
will not be used until such amendment is effective, and that, for purposes of
determining any liability under the Securities act of 1933, each such
post-effective amendment shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.
 
    The undersigned Registrant hereby undertakes to respond to requests for
information that is incorporated by reference into the prospectus pursuant to
Item 4, 10(b), 11, or 13 of this Form, within one business day of receipt of
such request, and to send the incorporated documents by first class mail or
other equally prompt means. This includes information contained in documents
filed subsequent to the effective date of the Registration Statement through the
date of responding to the request.
 
    The undersigned Registrant hereby undertakes to supply by means of a
post-effective amendment all information concerning a transaction, and the
company being acquired involved therein, that was not the subject of and
included in the Registration Statement when it became effective.
 
                                      II-8
<PAGE>
                                   SIGNATURES
 
   
    Pursuant to the requirements of the Securities Act of 1933, as amended,
Metromedia Fiber Network, Inc. has duly caused this Amendment No. 1 to
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of New York, State of New York, on February 11,
1999.
    
 
<TABLE>
<S>                             <C>  <C>
                                METROMEDIA FIBER NETWORK, INC.
 
                                By:  *
                                     -----------------------------------------
                                     Name: Stephen A. Garofalo
                                     Title: Chief Executive Officer and
                                     Chairman of the Board of Directors
</TABLE>
 
   
    Pursuant to the requirements of the Securities Act of 1933, this Amendment
No. 1 to Registration Statement has been signed below by the following persons
in the capacities indicated below and on February 11, 1999.
    
 
<TABLE>
<CAPTION>
          SIGNATURE                       TITLE
- ------------------------------  --------------------------
 
<C>                             <S>                         <C>
              *                 Chief Executive Officer
- ------------------------------    and Chairman of the
     Stephen A. Garofalo          Board of Directors
 
     /s/ GERARD BENEDETTO
- ------------------------------  Vice President--Chief
       Gerard Benedetto           Financial Officer
 
              *
- ------------------------------  President, Chief Operating
    Howard M. Finkelstein         Officer and Director
 
- ------------------------------  Senior Vice President and
     Vincent A. Galluccio         Director
 
              *
- ------------------------------  Executive Vice President
        Silvia Kessel             and Director
 
              *
- ------------------------------  Director
        John W. Kluge
 
- ------------------------------  Director
      David Rockefeller
</TABLE>
 
                                      II-9
<PAGE>
<TABLE>
<CAPTION>
          SIGNATURE                       TITLE
- ------------------------------  --------------------------
 
<C>                             <S>                         <C>
              *
- ------------------------------  Director
       Stuart Subotnick
 
              *                 Executive Vice President,
- ------------------------------    General Counsel,
       Arnold L. Wadler           Secretary and Director
 
- ------------------------------  Director
        Leonard White
</TABLE>
 
   
<TABLE>
  <S>  <C>
       /s/ GERARD BENEDETTO
       ------------------------------------------
       Name: Gerard Benedetto
  *By: Title:ATTORNEY-IN-FACT
</TABLE>
    
 
                                     II-10
<PAGE>
                                 EXHIBIT INDEX
 
   
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                                DESCRIPTION                                                PAGE
- -----------  -------------------------------------------------------------------------------------------------     -----
<S>          <C>                                                                                                <C>
 
       3.1   Form of Amended and Restated Certificate of Incorporation of Metromedia Fiber Network, Inc.
             (incorporated by reference to the Company's Registration Statement on Form S-1 (Registration No.
             333-33653)).
 
       3.2   Form of Amended and Restated Bylaws of Metromedia Fiber Network, Inc. (incorporated by reference
             to the Company's Registration Statement on Form S-1 (Registration No. 333-33653)).
 
       4.1   Specimen Class A Common Stock Certificate of Metromedia Fiber Network, Inc. (incorporated by
             reference to the Company's Registration Statement on Form S-1 (Registration No. 333-33653)).
 
       4.2   Indenture, dated as of November 25, 1998, between Metromedia Fiber Network, Inc. and IBJ
             Whitehall Bank & Trust Company (formerly IBJ Schroder Bank & Trust Company).
 
       4.3   Form of 10% Series A Senior Notes due 2008 of Metromedia Fiber Network, Inc.
 
      4.4*   Form of 10% Series B Senior Notes due 2008 of Metromedia Fiber Network, Inc.
 
       5.1   Opinion of Paul, Weiss, Rifkind, Wharton & Garrison regarding the legality of the Exchange Notes.
 
       8.1   Opinion of Paul, Weiss, Rifkind, Wharton & Garrison regarding certain United States federal
             income tax matters.
 
      10.1   Form of Metromedia Fiber Network, Inc. 1997 Incentive Stock Plan (incorporated by reference to
             the Company's Registration Statement on Form S-1 (Registration No. 333-33653)).
 
      10.2   Employment Agreement by and between National Fiber Network, Inc. and Stephen A. Garofalo, dated
             as of February 26, 1997 (incorporated by reference to the Company's Registration Statement on
             Form S-1 (Registration No. 333-33653)).
 
      10.3   Employment Agreement by and between National Fiber Network, Inc. and Howard Finkelstein, dated as
             of April 30, 1997 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
 
      10.4   Agreement dated as of April 30, 1997, as amended by a Modification Agreement dated as of October,
             1997 by and among Metromedia Company, Stuart Subotnick, Arnold Wadler, Silvia Kessel, Stephen A.
             Garofalo and National Fiber Network, Inc. (incorporated by reference to the Company's
             Registration Statement on Form S-1 (Registration No. 333-33653)).
 
      10.5   Franchise Agreement between The City of New York and National Fiber Network, Inc., dated as of
             December 20, 1993 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
 
      10.6   Conduit Occupancy Agreement by and between New York Telephone Company and National Fiber Network,
             Inc., dated as of May 1993 (incorporated by reference to the Company's Registration Statement on
             Form S-1 (Registration No. 333-33653)).
 
      10.7   Consulting Agreement between National Fiber Network and Realprop Capital Corporation, dated as of
             February 1, 1996 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
</TABLE>
    
<PAGE>
   
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                                DESCRIPTION                                                PAGE
- -----------  -------------------------------------------------------------------------------------------------     -----
<S>          <C>                                                                                                <C>
      10.8   Letter Agreement from National Fiber Network, Inc. to Peter Sahagen, dated February 11, 1997
             (incorporated by reference to the Company's Registration Statement on Form S-1 (Registration No.
             333-33653)).
 
      10.9   Office Lease by and between National Fiber Network, Inc. and 110 East 42nd Street Associates,
             dated as of March 19, 1997 (incorporated by reference to the Company's Registration Statement on
             Form S-1 (Registration No. 333-33653)).
 
     10.10   Office Lease by and between National Fiber Network, Inc. and 110 East 42nd Street, dated as of
             June 1997 (incorporated by reference to the Company's Registration Statement on Form S-1
             (Registration No. 333-33653)).
 
     10.11   Trademark License Agreement by and between Metromedia Company and Metromedia Fiber Network, Inc.,
             dated as of August 14, 1997 (incorporated by reference to the Company's Registration Statement on
             Form S-1 (Registration No. 333-33653)).
 
     10.12   Fiber Optic Use Agreement between National Fiber Network, Inc. and NextLink New York, L.L.C.,
             dated as of June 3, 1997 (portions of this exhibit are subject to a request to the Securities and
             Exchange Commission for confidential treatment, and omitted material has been separately filed
             with the Securities and Exchange Commission) (incorporated by reference to the Company's
             Registration Statement on Form S-1 (Registration No. 333-33653)).
 
     10.13   Amended and Restated Agreement for the Provision of a Fiber Optic Transmission Network, dated as
             of the Effective Date by and between US ONE Communications of New York, Inc. and National Fiber
             Network, Inc. (portions of this exhibit are subject to a request to the Securities and Exchange
             Commission for confidential treatment, and omitted material has been separately filed with the
             Securities and Exchange Commission) (incorporated by reference to the Company's Registration
             Statement on Form S-1 (Registration No. 333-33653)).
 
     10.14   Fiber Lease and Innerduct Use Agreement by and between Metromedia Fiber Network, Inc. and
             NextLink Communications, Inc., dated as of February 23, 1998 (portions of this exhibit are
             subject to a request to the Securities and Exchange Commission for confidential treatment, and
             omitted material has been separately filed with the Securities and Exchange Commission)
             (incorporated by reference to the Company's Annual Report on Form 10-K (File No.000-2369)).
 
     10.15   Amendment No. 1 to Fiber Lease and Innerduct Use Agreement by and between Metromedia Fiber
             Network, Inc. and NextLink Communications, Inc., made and entered into as of March 4, 1998
             (portions of this exhibit are subject to a request to the Securities and Exchange Commission for
             confidential treatment, and omitted material has been separately filed with the Securities and
             Exchange Commission) (incorporated by reference to the Company's Annual Report on Form 10-K (File
             No.000-2369)).
 
     10.16   Agreement of Lease by and between Connecticut General Life Insurance Company and Metromedia Fiber
             Network Services, Inc., dated as of March 9, 1998 (incorporated by reference to the Company's
             Annual Report on Form 10-K (File No. 000-2369)).
 
     10.17   Purchase Agreement, dated November 20, 1998 among Metromedia Fiber Network, Inc., Salomon Smith
             Barney, Inc., Chase Securities, Inc., Deutsche Bank Securities Inc. and Donaldson Lufkin &
             Jenrette Securities Corporation.
 
     10.18   Registration Rights Agreement, dated as of November 25, 1998 among Metromedia Fiber Network,
             Inc., Salomon Smith Barney, Inc., Chase Securities, Inc., Deutsche Bank Securities Inc. and
             Donaldson Lufkin & Jenrette Securities Corporation.
</TABLE>
    
<PAGE>
   
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                                DESCRIPTION                                                PAGE
- -----------  -------------------------------------------------------------------------------------------------     -----
<S>          <C>                                                                                                <C>
     10.19   Security Agreement, dated as of November 25, 1998, between Metromedia Fiber Network, Inc. and IBJ
             Schroder Bank & Trust Company.
 
    10.20*   Employment Agreement by and between Metromedia Fiber Network, Inc. and Vincent A. Galluccio,
             dated as of August 31, 1998.
 
    10.21*   Employment Agreement by and between Metromedia Fiber Network, Inc. and Gerard Benedetto, dated as
             of August 31, 1998.
 
    10.22*   Employment Agreement by and between Metromedia Fiber Network, Inc. and Nicholas M. Tanzi, dated
             as of August 31, 1998.
 
     12.1*   Statement Regarding Computation of Ratios.
 
      21.1   List of Subsidiaries of Metromedia Fiber Network, Inc.
 
     23.1*   Consent of Ernst & Young LLP.
 
     23.2*   Consent of M.R. Weiser & Co. LLP.
 
      23.3   Consent of Paul, Weiss, Rifkind, Wharton & Garrison (included in the opinion filed as Exhibit 5.1
             to this Registration Statement).
 
      23.4   Consent of Paul, Weiss, Rifkind, Wharton & Garrison (included in the opinion filed as Exhibit 8.1
             to this Registration Statement).
 
      24.1   Power of Attorney from officers and directors.
 
      25.1   Statement of Eligibility of IBJ Whitehall Bank & Trust Company as Trustee, on Form T-1.
 
     99.1*   Form of Exchange Agency Agreement.
 
     99.2*   Form of Letter of Transmittal.
 
     99.3*   Form of Notice of Guaranteed Delivery.
</TABLE>
    
 
- ------------------------
 
   
*   Filed herewith.
    

   <PAGE>
                                                                     Exhibit 4.4


          UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN
DEFINITIVE FORM, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE
DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO
THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY
SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR
DEPOSITARY, UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
OF THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) ("DTC") TO
THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND
ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER
NAME AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT
IS MADE TO CEDE & CO. OR SUCH OTHER ENTITY AS MAY BE REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER
HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

          THIS GLOBAL NOTE IS HELD BY THE DEPOSITARY (AS DEFINED IN THE
INDENTURE GOVERNING THIS NOTE) OR ITS NOMINEE IN CUSTODY FOR THE BENEFIT OF THE
BENEFICIAL OWNERS HEREOF, AND IS NOT TRANSFERABLE TO ANY PERSON UNDER ANY
CIRCUMSTANCES EXCEPT THAT (I) THE TRUSTEE MAY MAKE SUCH NOTATIONS HEREON AS MAY
BE REQUIRED PURSUANT TO SECTION 2.06 OF THE INDENTURE, (II) THIS GLOBAL NOTE MAY
BE EXCHANGED IN WHOLE BUT NOT IN PART PURSUANT TO SECTION 2.06(a) OF THE
INDENTURE, (III) THIS GLOBAL NOTE MAY BE DELIVERED TO THE TRUSTEE FOR
CANCELLATION PURSUANT TO SECTION 2.11 OF THE INDENTURE AND (IV) THIS GLOBAL NOTE
MAY BE TRANSFERRED TO A SUCCESSOR DEPOSITARY WITH THE PRIOR WRITTEN CONSENT OF
THE COMPANY.


<PAGE>
                                                                                


                                                  CUSIP 
                                                                                
                          10% SERIES B SENIOR NOTES DUE 2008
No.                                                    $                        


                            METROMEDIA FIBER NETWORK, INC.


promises to pay to Cede & Co. or registered assigns, the principal sum of

Dollars on November 15, 2008.


                   Interest Payment Dates:  May 15 and November 15.
                         Record Dates:  May 1 and November 1.


                                        METROMEDIA FIBER NETWORK, INC.

                                        By:
                                             Name:
                                             Title:

                                        By:
                                             Name:
                                             Title:



This is one of the Notes referred to in the
within-mentioned Indenture:


IBJ WHITEHALL BANK & TRUST COMPANY,
as Trustee



By:                                Dated:
     Name:     
     Title:


<PAGE>
                                                                               2

                                   (BACK OF NOTE)

                          10% Series B Senior Notes due 2008

          Capitalized terms used herein shall have the meanings assigned to them
in the Indenture referred to below unless otherwise indicated.

          1.   INTEREST.  Metromedia Fiber Network, Inc., a Delaware corporation
(the "Company"), promises to pay interest on the principal amount of this Note
at 10% per annum from November 25, 1998 until maturity and shall pay the
Liquidated Damages payable in accordance with the provisions of the following
paragraph.  The Company shall pay interest and Liquidated Damages semi-annually
on May 15 and November 15 of each year, or if any such day is not a Business
Day, on the next succeeding Business Day (each an "INTEREST PAYMENT DATE"). 
Interest on the Notes shall accrue from the most recent date to which interest
has been paid or, if no interest has been paid, from the date of issuance;
PROVIDED that if there is no existing Default or Event of Default relating to
the payment of interest, and if this Note is authenticated between a Record Date
referred to on the face hereof and the next succeeding Interest Payment Date,
interest shall accrue from such next succeeding Interest Payment Date; PROVIDED,
FURTHER, that the first Interest Payment Date shall be May 15, 1999.  The
Company shall pay interest (including post-petition interest in any proceeding
under any Bankruptcy Law) on overdue principal and premium, if any, from time to
time on demand at a rate that is 1.0% per annum in excess of the rate then in
effect; it shall pay interest (including post-petition interest in any
proceeding under any Bankruptcy Law) on overdue installments of interest and
Liquidated Damages (without regard to any applicable grace periods) from time to
time on demand at the same rate to the extent lawful.  Interest shall be
computed on the basis of a 360-day year of twelve 30-day months.

          The Holder of this Note is entitled to the benefits of the
Registration Rights Agreement.  If (a) the Company fails to file any of the
Registration Statements required by the Registration Rights Agreement on or
before the date specified for such filing, (b) any of such Registration
Statements is not declared effective by the SEC on or prior to the date
specified for such effectiveness, or (c) the Company fails to consummate the
Registered Exchange Offer within 210 Business Days of the Closing Date with
respect to the Exchange Offer Registration Statement, or (d) any Registration
Statement required by the Registration Rights Agreement is declared effective
but thereafter ceases to be effective or usable in connection with its intended
purpose (each such event referred to in clauses (a) through (d) above a
"REGISTRATION DEFAULT"), then the Company shall pay to each holder of Transfer
Restricted Notes (as defined in the Registration Rights Agreement) affected
thereby liquidated damages ("LIQUIDATED DAMAGES") which shall accrue and be
payable semi-annually on the Notes and the Exchange Notes (in addition to the
stated interest on the Notes and the Exchange Notes) from and including the date
such Registration Default occurs to, but excluding the date on which the
applicable Registration Statement is filed or is declared effective, the
Registered Exchange Offer is consummated, or the applicable Registration
Statement is again declared effective or made usable.  During the time that
Liquidated Damages is accruing continuously, the rate of such Liquidated Damages
shall be 0.50% per annum during the first 90-day period and shall increase by
0.25% per annum for each subsequent 90-day period, but in no event shall such
rate exceed 1.50% per annum in the aggregate regardless of the number of
Registration Defaults.  If, after the cure of all Registration Defaults then in
effect, there is a subsequent Registration Default, the rate of Liquidated
Damages for such subsequent Registration Default shall initially be 0.50%,
regardless of the Liquidated Damages rate in effect with respect to any prior
Registration Default at the time of the cure of such Registration Default.

<PAGE>
                                                                               3


          2.   METHOD OF PAYMENT.  The Company shall pay interest on the Notes
(except defaulted interest) and Liquidated Damages to the Persons who are
registered Holders of Notes at the close of business on the May 1 or November 1
next preceding the Interest Payment Date, even if such Notes are canceled after
such Record Date and on or before such Interest Payment Date, except as provided
in Section 2.12 of the Indenture with respect to defaulted interest.  The Notes
shall be payable as to principal, premium and Liquidated Damages, if any, and
interest at the office or agency of the Company maintained for such purpose
within or outside of the City and State of New York, or, at the option of the
Company, payment of interest and Liquidated Damages may be made by check mailed
to the Holders at their addresses set forth in the register of Holders kept by
the Registrar, and PROVIDED that payment by wire transfer of immediately
available funds shall be required with respect to principal of and interest,
premium and Liquidated Damages on, all Global Notes and all other Notes the
Holders of which shall have provided wire transfer instructions to the Company
or the Paying Agent.  Such payment shall be in such coin or currency of the
United States of America as at the time of payment is legal tender for payment
of public and private debts.

          3.   PAYING AGENT AND REGISTRAR.  Initially, IBJ Whitehall Bank &
Trust Company, the Trustee under the Indenture, shall act as Paying Agent and
Registrar.  The Company may change any Paying Agent or Registrar without notice
to any Holder.  The Company or any of its Restricted Subsidiaries may act in any
such capacity.

          4.   INDENTURE.  The Company issued the Notes under an Indenture dated
as of November 25, 1998 ("INDENTURE") between the Company and the Trustee.  The
terms of the Notes include those stated in the Indenture and those made part of
the Indenture by reference to the Trust Indenture Act of 1939, as amended (15
U.S. Code Sections  77aaa-77bbbb) (the "TIA").  The Notes are subject to all
such terms, and Holders are referred to the Indenture and the TIA for a
statement of such terms.  To the extent any provision of this Note conflicts
with the express provisions of the Indenture, the provisions of the Indenture
shall govern and be controlling.  The Notes are obligations of the Company
limited to $650.0 million in aggregate principal amount.

          5.   OPTIONAL REDEMPTION.

               (a)  Except as set forth in subparagraphs (b) and (c) below, the
Notes shall not be redeemable at the Company's option prior to November 15,
2003. Thereafter, the Notes shall be subject to redemption at any time at the
option of the Company, in whole or in part, upon not less than 30 nor more than
60 days' notice, at the redemption prices (expressed as percentages of principal
amount) set forth below, plus accrued and unpaid interest (and Liquidated
Damages, if any) thereon to the applicable redemption date (subject to the right
of Holders of record on the relevant Record Date to receive interest due on the
relevant Interest Payment Date), if redeemed during the twelve-month period
beginning on November 15 of the years indicated below:

               YEAR                            PERCENTAGE OF
               ----                          PRINCIPAL AMOUNT
                                             ----------------

               2003                             105.000%
               2004                             103.333%
               2005                             101.667%
               2006 and thereafter              100.000%

               (b)  Notwithstanding the foregoing, at any time prior to November
15, 2001, the Company may, on any one or more occasions, redeem up to 35% of the
aggregate principal amount of Notes originally issued pursuant to the Indenture
at a redemption price of 110.000% of the principal amount thereof, plus accrued
and unpaid interest (and Liquidated

<PAGE>
                                                                               4


Damages, if any) thereon to the redemption date (subject to the right of Holders
of record on the relevant Record Date to receive interest due on the relevant
Interest Payment Date), with the Net Cash Proceeds received from any Public
Equity Offering made by the Company resulting in gross proceeds to the Company
of at least $100 million; PROVIDED that at least 65% of the aggregate principal
amount of Notes originally issued pursuant to the Indenture remain outstanding
immediately after the occurrence of any such redemption.  The Company may make
any such redemption upon not less than 30 nor more than 60 days' notice (but in
no event more than 90 days after the closing of the related Public Equity
Offering).

               (c)  Any redemption pursuant to this Section 5 shall be made
pursuant to the provisions of Section 3.01 through 3.06 of the Indenture.

          6.   MANDATORY REDEMPTION.

          The Company shall not be required to make mandatory redemption or
sinking fund payments with respect to the Notes.

          7.   REPURCHASE AT OPTION OF HOLDER.

               (a)  Upon the occurrence of a Change of Control, each Holder of
Notes will have the right to require the Company to purchase all or any part
(equal to $1,000 or an integral multiple thereof) of such Holder's Notes
pursuant to the offer described below (the "Change of Control Offer") at a
purchase price in cash equal to 101% of the aggregate principal amount thereof
(the "Change of Control Payment") plus accrued and unpaid interest (and
Liquidated Damages, if any) thereon to the date of purchase (subject to the
right of Holders of record on the relevant Record Date to receive interest due
on the relevant Interest Payment Date).  Within 30 days following any Change of
Control, the Company will mail a notice to each Holder setting forth the
procedures governing the Change of Control Offer as required by the Indenture.

               (b)  The Company shall not, and shall not permit any of its
Restricted Subsidiaries to, directly or indirectly, consummate any Asset Sale,
unless (i) the Company (or such Restricted Subsidiary, as the case may be)
receives consideration at the time of such Asset Sale at least equal to the fair
market value (as determined in good faith by the Board of Directors (including
as to the value of all noncash consideration) and set forth in an Officer's
Certificate delivered to the Trustee) of the assets or Equity Interests issued
or sold or otherwise disposed of and (ii) at least 75% of the consideration
therefor is in the form of cash and/or Cash Equivalents or Telecommunications
Assets, and (iii) the Net Cash Proceeds received by the Company (or such
Restricted Subsidiary, as the case may be) from such Asset Sale are applied
within 360 days following the receipt of such Net Cash Proceeds, to the extent
the Company (or such Restricted Subsidiary, as the case may be) elects, (a) to
the permanent redemption or repurchase of outstanding Indebtedness (other than
Subordinated Indebtedness) that is secured Indebtedness (including that in the
case of a revolver or similar arrangement that makes credit available, such
commitment is so permanently reduced by such amount) or Indebtedness of the
Company or such Restricted Subsidiary that ranks equally with the Notes but has
a maturity date that is prior to the maturity date of the Notes and/or (b) to
reinvest such Net Cash Proceeds (or any portion thereof) in Telecommunications
Assets.  Notwithstanding anything herein to the contrary, with respect to the
reinvestment of Net Cash Proceeds, only proceeds from an Asset Sale of assets,
or Equity Interests, of a Foreign Subsidiary may be used to retire Indebtedness
of a Foreign Subsidiary or reinvest in assets or Equity Interests of a Foreign
Subsidiary.  The balance of such Net Cash Proceeds, after the application of
such Net Cash Proceeds as described in the immediately preceding clauses (a) and
(b), shall constitute "Excess Proceeds."

               (c)  When the aggregate amount of Excess Proceeds equals or
exceeds $15.0 million (taking into account income earned on such Excess
Proceeds), the Company will be required to make a pro rata offer to all Holders
of Notes and  PARI PASSU Indebtedness with

<PAGE>
                                                                               5


comparable provisions requiring such Indebtedness to be purchased with the
proceeds of such Asset Sale (an "Asset Sale Offer") to purchase the maximum
principal amount or accreted value in the case of Indebtedness issued with an
original issue discount of Notes and PARI PASSU Indebtedness that may be
purchased out of the Excess Proceeds, at a purchase price in cash in an amount
equal to 100% of the principal amount thereof or the accreted value thereof, as
applicable, plus accrued and unpaid interest thereon to the date of purchase
(subject to the right of Holders of record on the relevant Record Date to
receive interest due on the relevant Interest Payment Date), in accordance with
the procedures set forth in Article 3 of the Indenture and the agreements
governing such PARI PASSU Indebtedness.  To the extent that any Excess Proceeds
remain after consummation of an Asset Sale Offer, the Company may use such
Excess Proceeds for any purpose not otherwise prohibited by the Indenture.  If
the aggregate principal amount of Notes and  PARI PASSU Indebtedness tendered
into such Asset Sale Offer surrendered by Holders thereof exceeds the amount of
Excess Proceeds, the Trustee shall select the Notes and PARI PASSU Indebtedness
to be purchased on a pro rata basis in proportion to the respective principal
amounts (or accreted values in the case of Indebtedness issued with an original
issue discount) of the Notes and such other Indebtedness.  Upon completion, of
such Asset Sale Offer, the amount of Excess Proceeds shall be reset at zero for
purposes of the first sentence of this paragraph.

          8.   NOTICE OF REDEMPTION.  Notice of redemption shall be mailed at
least 30 days but not more than 60 days before the redemption date to each
Holder whose Notes are to be redeemed at its registered address. Notes in
denominations larger than $1,000 may be redeemed in part but only in whole
multiples of $1,000, unless all of the Notes held by a Holder are to be
redeemed. On and after the redemption date interest shall cease to accrue on
Notes or portions thereof called for redemption.

          9.   DENOMINATIONS, TRANSFER, EXCHANGE.  The Notes are in registered
form without coupons in denominations of $1,000 and integral multiples of
$1,000. The transfer of Notes may be registered and Notes may be exchanged as
provided in the Indenture. The Registrar and the Trustee may require a Holder,
among other things, to furnish appropriate endorsements and transfer documents
and the Company may require a Holder to pay any taxes and fees required by law
or permitted by the Indenture. The Company need not exchange or register the
transfer of any Note or portion of a Note selected for redemption, except for
the unredeemed portion of any Note being redeemed in part. Also, the Company
need not exchange or register the transfer of any Notes for a period of 15
Business Days before a selection of Notes to be redeemed or during the period
between a Record Date and the corresponding Interest Payment Date.

          10.  PERSONS DEEMED OWNERS.  The registered Holder of a Note on the
Registrar's books may be treated as its owner for all purposes under the
Indenture.

          11.  AMENDMENT, SUPPLEMENT AND WAIVER.  Subject to certain exceptions,
the Indenture and the Notes may be amended or supplemented with the consent of
the Holders of at least a majority in aggregate principal amount of the then
outstanding Notes voting as a single class, and any existing default or
compliance with any provision of the Indenture or the Note may be waived with
the consent of the Holders of a majority in aggregate principal amount of the
then outstanding Notes voting as a single class. Without the consent of any
Holder of a Note, the Indenture or the Notes may be amended or supplemented
among other things,  to cure any ambiguity, omission, defect or inconsistency,
to provide for uncertificated Notes in addition to or in place of certificated
Notes, to provide for the assumption of the Company's obligations to Holders of
the Notes in case of a merger or consolidation or sale of all or substantially
all of the Company's assets in accordance with the terms of the Indenture, to
make any change that would provide any additional rights or benefits to the
Holders of the Notes or that does not adversely affect the legal rights under
the Indenture of any such Holder, to comply with the requirements of the SEC in
order to effect or maintain the qualification of the Indenture under the TIA, to
add to the covenants of the Company for the benefit of the Holders or to
surrender any right or power

<PAGE>
                                                                               6


conferred by the Indenture upon the Company, to provide for the issuance of the
Unrestricted Notes under the Exchange Offer contemplated by the Registration
Rights Agreement, or to effect any change to the transfer and exchange
restrictions and security delivery procedures contained in the Indenture in
order to conform with changes in any applicable law or Applicable Procedures.

          12.  DEFAULTS AND REMEDIES.

               (a)  Events of Default under the Indenture include: (i) the
failure to pay interest on, or Liquidated Damages, if any, with respect to the
Notes, when the same becomes due and payable if such default continues for a
period of 30 days, (ii) the failure to pay principal of any Notes when such
principal becomes due and payable, at maturity, upon redemption or otherwise;
(iii) failure by the Company or any Restricted Subsidiary to comply with
Sections 4.10 or 4.14 of the Indenture; (iv) failure by the Company or any
Restricted Subsidiary for 60 days after notice to comply with any of its other
agreements in the Indenture or this Note; (v) default under any mortgage,
indenture or instrument under which there may be issued or by which there may be
secured or evidenced any Indebtedness for money borrowed by the Company or any
of its Restricted Subsidiaries (or the payment of which is Guaranteed by the
Company or any of its Restricted Subsidiaries) whether such Indebtedness or
Guarantee now exists, or is created after the Issue Date, which default results
in the acceleration of such Indebtedness prior to its express maturity and, in
each case, the principal amount of any such Indebtedness, together with the
principal amount of any other such Indebtedness or the maturity of which has
been so accelerated, aggregates $15.0 million or more; (vi) failure by the
Company or any of its Restricted Subsidiaries to pay final judgments not subject
to appeal aggregating in excess of $15.0 million (net of applicable insurance
coverage which is acknowledged in writing by the insurer), which judgments are
not paid, vacated, discharged or stayed for a period of 60 days; and (vii)
certain events of bankruptcy or insolvency with respect to the Company or any of
the Company's Restricted Subsidiaries.

               (b)  If any Event of Default occurs and is continuing, the
Trustee or the Holders of at least 25% in aggregate principal amount of the then
outstanding Notes may declare all the Notes to be due and payable.
Notwithstanding the foregoing, in the case of an Event of Default arising from
certain events of bankruptcy or insolvency, all outstanding Notes shall become
due and payable without further action or notice. Holders may not enforce the
Indenture or the Notes except as provided in the Indenture. Subject to certain
limitations, Holders of a majority in principal amount of the then outstanding
Notes may direct the Trustee in its exercise of any trust or power. The Trustee
may withhold from Holders of the Notes notice of any continuing Default or Event
of Default (except a Default or Event of Default relating to the payment of
principal or interest) if it determines that withholding notice is in their
interest. Except as provided in the Indenture, the Holders of a majority in
principal amount of the then outstanding Notes by notice to the Trustee may on
behalf of the Holders of all of the Notes waive any existing Default or Event of
Default and its consequences under the Indenture, except a continuing Default or
Event of Default in the payment of interest on, or principal of, the Notes.  The
Company shall deliver to the Trustee annually a statement regarding compliance
with the Indenture, and the Company, upon becoming aware of any Default or Event
of Default, deliver to the Trustee a statement specifying such Default or Event
of Default.

          13.  TRUSTEE DEALINGS WITH COMPANY.  The Trustee, in its individual or
any other capacity, may make loans to, accept deposits from, and perform
services for the Company or its Affiliates, and may otherwise deal with the
Company or its Affiliates, as if it were not the Trustee.

          14.  NO RECOURSE AGAINST OTHERS.  A director, officer, employee,
incorporator or shareholder, of the Company, as such, shall not have any
liability for any obligations of the Company under the Notes or the Indenture or
for any claim based on, in respect of, or by reason of, such obligations or
their creation. Each Holder by accepting a Note waives

<PAGE>
                                                                               7


and releases all such liability. The waiver and release are part of the
consideration for the issuance of the Notes.

          15.  AUTHENTICATION.  This Note shall not be valid until authenticated
by the manual signature of the Trustee or an authenticating agent.

          16.  ABBREVIATIONS.  Customary abbreviations may be used in the name
of a Holder or an assignee, such as: TEN COM (= tenants in common), TEN ENT (=
tenants by the entirety), JT TEN (= joint tenants with right of survivorship and
not as tenants in common), CUST (= Custodian), and U/G/M/A (= Uniform Gifts to
Minors Act).

          17.  ADDITIONAL RIGHTS OF HOLDERS OF RESTRICTED GLOBAL NOTES AND
RESTRICTED DEFINITIVE NOTES.  In addition to the rights provided to Holders of
Notes under the Indenture, Holders of Notes shall have all the rights set forth
in the Registration Rights Agreement.

          18.  CUSIP NUMBERS.  Pursuant to a recommendation promulgated by the
Committee on Uniform Security Identification Procedures, the Company has caused
CUSIP numbers to be printed on the Notes and the Trustee may use CUSIP numbers
in notices of redemption as a convenience to Holders. No representation is made
as to the accuracy of such numbers either as printed on the Notes or as
contained in any notice of redemption and reliance may be placed only on the
other identification numbers placed thereon.

          The Company will furnish to any Holder upon written request and
without charge a copy of the Indenture and/or the Registration Rights Agreement.
Requests may be made to:

          Metromedia Fiber Network Services, Inc.
          c/o Metromedia Fiber Network, Inc.
          One North Lexington Avenue
          White Plains, NY 10601
          Attention:  Chief Financial Officer


<PAGE>
                                                                               8


                                  ASSIGNMENT FORM

To assign this Note, fill in the form below: (I) or (we) assign and transfer
this Note to

______________________________________________________________________________


                    (Insert assignee's soc. sec. or tax I.D. no.)


______________________________________________________________________________



______________________________________________________________________________



______________________________________________________________________________

                                                                                
                                                                                
(Print or type assignee's name, address and zip code)

and irrevocably appoint_______________________________________________________
to transfer this Note on the books of the Company. The agent may substitute
another to act for him.

______________________________________________________________________________

Date:                              Your Signature:____________________________
                                   (Sign exactly as your name appears on the
                                   face of this Note)

                                   Tax Identification No:_____________________
                                   SIGNATURE GUARANTEE:


                                   _______________________________________

                                   Signatures must be guaranteed by an "eligible
                                   guarantor institution" meeting the
                                   requirements of the Registrar, which
                                   requirements include membership or
                                   participation in the Security Transfer Agent
                                   Medallion Program ("STAMP") or such other
                                   "signature guarantee program" as may be
                                   determined by the Registrar in addition to,
                                   or in substitution for, STAMP, all in
                                   accordance with the Securities Exchange Act
                                   of 1934, as amended.


<PAGE>
                                                                               9


                          OPTION OF HOLDER TO ELECT PURCHASE

          If you want to elect to have this Note purchased by the Company
pursuant to Section 4.10 or 4.14 of the Indenture, check the box below:

          / / Section 4. 10   / / Section 4.14

          If you want to elect to have only part of the Note purchased by the
Company pursuant to Section 4. 10 or Section 4.14 of the Indenture, state the
amount you elect to have purchased: $_____________________


Date:___________________________   Your Signature:___________________________
                                   (Sign exactly as your name appears on the
                                   face of this Note)

                                   Tax Identification No:____________________

                                   SIGNATURE GUARANTEE:

                                   __________________________________________

                                   Signatures must be guaranteed by an "eligible
                                   guarantor institution" meeting the
                                   requirements of the Registrar, which
                                   requirements include membership or
                                   participation in the Security Transfer Agent
                                   Medallion Program ("STAMP") or such other
                                   "signature guarantee program" as may be
                                   determined by the Registrar in addition to,
                                   or in substitution for, STAMP, all in
                                   accordance with the Securities Exchange Act
                                   of 1934, as amended.

<PAGE>
                                                                              10


                SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL NOTE

          The following exchanges of a part of this Global Note for an interest
in another Global Note or for a Definitive Note, or exchanges of a part of
another Global Note or Definitive Note for an interest in this Global Note, have
been made:

<TABLE> 
<CAPTION>
                                                                   Principal Amount
                     Amount of decrease    Amount of increase    of this Global Note       Signature of
                        in Principal          in Principal          following such      authorized officer
                       Amount of this        Amount of this            decrease           of Trustee or
Date of Exchange        Global Note           Global Note            (or increase)        Note Custodian
- ----------------     ------------------    ------------------    -------------------    ------------------
<S>                  <C>                   <C>                   <C>                    <C>







</TABLE>

<PAGE>
                                                                   Exhibit 10.20


                                 EMPLOYMENT AGREEMENT

     AGREEMENT, dated as of August 31, 1998, by and between METROMEDIA FIBER
NETWORK, INC., a Delaware corporation having its principal offices at 1 North
Lexington Avenue, White Plains, New York  10601 (the "Company"), and Vincent A.
Galluccio, residing at 244 Shopping Avenue, Sarasota, Florida  34237 (the
"EXECUTIVE").


                                 W I T N E S S E T H:
                                 - - - - - - - - - - 

     WHEREAS, to insure the continuity of senior management of the Company,
notwithstanding a material change in the ownership or business activities of the
Company,  the Company  and Executive desire to enter into this Agreement on the
terms and conditions hereinafter set forth;  

     WHEREAS, the Company has granted non-qualified stock options to purchase
75,000 shares (the "NQSO's") of the Company's Class A common stock, par value
$.01 per share ("Class A Common Stock"), to Executive under the Company's 1998
Incentive Stock Option Plan (the "Plan") pursuant to the Stock Option Agreement
between the Company and Executive dated of even date herewith (the "Stock Option
Agreement"); and

     WHEREAS, the Executive, as additional consideration for entering into this
Agreement with the Company, has agreed to forego his right to accelerate the
vesting of the NQSO's upon a Change in Control (as such term is defined in the
Plan).

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

     1.   EMPLOYMENT; TERM.

          (a)   The Company hereby employs the Executive, and the Executive
hereby agrees to serve, as Senior Vice President of the Company. 

          (b)   The term (the "Initial Term") of the Executive's employment
hereunder shall commence on August 31, 1998 and shall terminate on September 1,
1999 (the "EXPIRATION DATE"), unless sooner terminated as provided in paragraph
7 below.  The Company shall have the right to extend this Agreement for an
additional period of one year ("Additional Term"), upon written notice to
Executive, given not less than three (3) months prior to the termination of the
Initial Term.  The Initial Term and Additional Term are hereinafter sometimes
collectively referred to as the "Term".


                                           
<PAGE>

     2.   DUTIES.

          (a) The Executive agrees to perform his duties and exercise his 
authority pursuant to the direction and control of the President and shall 
report to the President or the President's designee as and when requested.  
The Executive shall have such powers and duties as assigned or changed by the 
President from time to time. The Executive shall perform his duties 
diligently, faithfully and to the best of his ability and in accordance with 
sound business practices.

          (b)   The Executive shall devote to the exclusion of other business
activities other than Permitted Activities (as hereinafter defined) all his
business time and attention to his duties and responsibilities hereunder,
subject to paid vacations and holidays as hereinafter set forth in Section 6(b)
of this Agreement.

          (c)  For purposes of this Agreement "Permitted Activities" shall mean
(i) passive business or charitable activities that may, from time to time,
require insubstantial portions of his business time, but which would not,
singularly or in the aggregate, interfere with the devotion of substantially all
his business attention and energies to the affairs of the Company, or his
obligations under this Agreement, or otherwise be inconsistent with his duties
hereunder and (ii) the ownership by the Executive (as the result of open market
purchase) of one (1%) percent or less of any class of capital stock of a
corporation which is regularly traded on a national securities exchange or
over-the-counter on the NASDAQ system. 

     3.   COMPENSATION.

          (a)   During the Term, the Executive shall receive an annual base
salary of  One Hundred Eighty Three Thousand Four Hundred ($183,400) Dollars
(the "BASE SALARY") subject to required deductions and withholdings as required
by law or agreement payable in accordance with the standard payroll practices of
the Company. 

          (b)  In addition to the Base Salary set forth in Section 3(a) hereof,
the Executive shall be entitled to participate in the Company's bonus program
(the "Bonus Plan") which is recommended by the President and is subject to the
approval of the Compensation Committee of the Board of Directors.  The Bonus
Plan is predicated on the Company attaining certain financial and other
objectives.  The Executive shall have an initial target of a bonus of [20%] of
the Executive's Base Salary set forth in  Section 3(a) hereof based upon
achieving 100% of the Bonus Plan's objectives.  The Bonus Plan is a calendar
year plan, as such, the bonus Executive may receive will be adjusted on the
basis of the Term.  For example, since the Term is to commence on August 31,
1998, if all objectives of the Bonus Plan are achieved the targeted bonus of 20%
will be prorated to $12,360.66 (i.e. $183,400 (.20/365 days)(123 days) =
$12,360.66).

          (c) It is understood that nothing contained herein shall prevent the
Company, in its sole and absolute discretion, from at any time increasing the
compensation herein provided to be paid to the Executive, either permanently or
for a


                                          2
<PAGE>

limited period, in the event the Company, in its sole and absolute discretion,
shall deem it advisable to do so in order to recognize and fairly compensate the
Executive for the value of his services to the Company; PROVIDED, HOWEVER, that
nothing in this Section 3(c) shall in any manner obligate the Company to make
any such increase or provide any such additional compensation or benefits to the
Executive.

     4.   STOCK OPTIONS.  (a) In accordance with the terms and conditions set
forth in the Stock Option Agreement, the Compensation Committee of the Board of
Directors granted to Executive under the Plan, non-qualified stock options
("NQSOs") for a total of 75,000 shares of Class A Common Stock bearing an
exercise price of $21.00 per share.   In consideration for entering into this
Agreement, Executive hereby agrees that in the event that there is a Change in
Control (as such term is defined in the Plan) of the Company, the NQSOs granted
to Executive pursuant to the Stock Option Agreement shall continue to vest in
accordance with the vesting schedule set forth in the Stock Option Agreement
and, notwithstanding paragraph 4 of the Stock Option Agreement, shall not
accelerate and shall not be immediately exercisable upon a Change of Control.


          (b)  Except as specifically provided herein, nothing contained in this
Agreement shall be deemed to modify in any respect the terms, provisions, or
conditions of the Stock Option Agreement and such terms, provisions and
conditions of the Stock Option Agreement shall remain in full force and effect.

     5.   EXPENSES.  The Company shall reimburse the Executive for all
reasonable out-of-pocket business expenses paid or incurred by him in connection
with the performance of his duties and responsibilities hereunder, but payment
shall be made only against a signed, itemized list of such expenses, utilizing
general forms for that purpose established by the Company.  

     6.   ADDITIONAL BENEFITS; VACATIONS; FACILITIES.

          (a)    The Executive shall be entitled to participate in all group
health and insurance programs and all other fringe benefit or retirement plans
or other plans effective generally with respect to senior executives of the
Company.  Nothing herein shall be deemed to require the Company to establish or
maintain any employee benefit plan whatsoever, and the Company shall have the
right, in its sole and absolute discretion, to alter, amend, modify, discontinue
or terminate any and all employee benefit plans at any time.  

          (b)   During the Term, the Executive shall be entitled to the same
paid holidays as are provided to executives of the Company generally and shall
be entitled to take periodic vacations with pay aggregating three weeks per
twelve-month period during the Term consistent with his duties and
responsibilities hereunder and the Company's vacation policy.  

          (c)   The Company shall furnish the Executive with such working 


                                          3
<PAGE>

facilities and other services as are suitable to his position and are adequate
for the performance of his duties hereunder.

     7.   TERMINATION OF EMPLOYMENT.  This Agreement may be terminated prior to
the Expiration Date in accordance with the following provisions:

          (a)In the event of the Executive's death prior to the Expiration Date,
this  Agreement shall automatically terminate.

          (b)  If the Executive shall suffer a Disability (as hereinafter
defined) prior to the Expiration Date, this Agreement may be terminated at the
option of the Company by notice from the Company to the Executive given at any
time after the Executive shall have suffered a Disability.  The term
"DISABILITY" shall mean that the Executive shall be unable for a period of
ninety (90) days or more during the Term, because of a physical or mental
illness or condition, to perform his duties hereunder.  In such event, such
termination shall be effective as of the date on which the Company gives notice
to the Executive that it is terminating his employment hereunder pursuant to
this Section 7(b) without further obligation to Executive other than to pay the
compensation and reimbursement amounts provided for herein prorated to the date
of such termination.

          (c)    In the event that there is a Change in Control (as such term is
defined in the Plan) of the Company and the Executive is requested in connection
therewith to perform his duties hereunder on a regular, full-time basis at a
location further than 75 miles from Executive's current principal office
location, the Executive, in his sole and absolute discretion, may deem this
Agreement to be terminated by the Company without Cause (as hereinafter defined)
and the Executive shall be entitled to receive from the Company the "Termination
Payments" set forth in Section 8 of this Agreement. 

          (d)   This Agreement may be terminated prior to the Expiration Date at
the option of the Company for Cause, effective as of the date on which the
Company gives notice to the Executive that it is terminating his employment
pursuant to this Section 7(d).  The term for "Cause" shall mean and include any
of the following events:

               (i)   fraud, misappropriation or embezzlement of funds or
property by the Executive involving the Company or an Affiliated Company (as
hereinafter defined);

               (ii)   the conviction of the Executive in any jurisdiction for
any crime which constitutes a felony, or which constitutes a misdemeanor that
involves fraud, moral turpitude or material loss to the Company or an Affiliated
Company, or their respective businesses or reputations;

               (iii)  the Executive's misconduct in, or neglect of, the
performance of his duties and responsibilities hereunder, or the Executive's
repeated violation of any reasonable specific written directions of the
President of the Company or the


                                          4
<PAGE>

President's designee which directions are consistent with the provisions of this
Agreement;

               (iv)  the Executive's breach of the agreements and covenants set
forth in Sections 9, 10, 11 or 12  hereof; or

               (v)   the Executive's material breach of any other provision of
this Agreement which breach continues uncured for five (5) days after written
notice thereof is given to the Executive by the Company or the President of the
Company.

     In the event of the termination of the Executive's employment hereunder for
"Cause", such termination shall be effective as of the date of notice of such
termination and the Company shall have no further obligations whatsoever
hereunder to compensate the Executive pursuant to the terms of this Agreement.

     The term "AFFILIATED COMPANIES" shall mean all entities that directly or
indirectly control, or are controlled by, the Company, all entities that are
under direct or indirect common control with the Company, and all entities in
which the Company has a significant joint venture or other similar interest. 
"CONTROL" and "CONTROLLED" shall mean possession, directly or indirectly, of the
power to direct or cause the direction of the management and policies of a
corporation, partnership or other entity, whether through ownership of voting
securities, by contract or otherwise.

     8.   TERMINATION PAYMENTS.  Upon the termination by the Company of
Executive's employment for any reason other than for Cause, the Executive shall
be entitled to receive from the Company (i) the Executive's unpaid Base Salary
for the remaining Term of Employment under this Agreement, (ii) all previously
earned and accrued entitlements and benefits from the Company and its employee
benefit plans and (iii) an amount equal to the product of the Executive's Base
Salary multiplied by .25.

     9.   CONFIDENTIAL INFORMATION.  The Executive covenants and agrees that:

          (a)   During the Term and thereafter, he will keep secret and retain
in the strictest confidence all information about business and financial matters
(including, without limitation, information relating to costs, profits, budgets
and plans for future development, strategy, methods of operation and marketing
concepts) of the Company and the Affiliated Companies, their respective
employment policies and plans, and any other trade secrets and proprietary
information relating to the Company, the Affiliated Companies or their
respective operations, business and financial affairs, other than information
which is otherwise generally available to the public other than as a result of a
disclosure by the Executive (collectively, the "CONFIDENTIAL INFORMATION"), and,
for such time as the Company or any Affiliated Company is operating, not
disclose any Confidential Information to anyone outside of the Company or an
Affiliated Company, either during or after the term of his employment by the
Company or an Affiliated Company, except (i) in the course of performing his
duties hereunder, (ii) with the Company's express prior written consent or (iii)
as required by law; and


                                          5
<PAGE>

          (b)   The Executive will surrender to the Company within ten (10) days
after the termination of his employment hereunder, or at any time the Company
may so request, all memoranda, notes, records, reports, lists and other
documents containing, describing or relating to Confidential Information,
together with all copies thereof, obtained by him or entrusted to him during the
course of his employment by the Company or an Affiliated Company or otherwise in
his possession at the time of such termination or request.

     10.  RESTRICTIVE COVENANTS

          Executive covenants and agrees that:

          (a) during the Term for any reason whatsoever he will not compete,
directly or indirectly, with the Company or any Affiliated Company, by
participating in the direct or indirect ownership, management, operation or
control, whether as an officer, director, partner, employee, advisor,
stockholder, investor, consultant, agent, independent contractor, lender or
otherwise, of any corporation, partnership or other entity which owns, acquires
or seeks to acquire or obtain any franchise, lease or license, relating to, or
is otherwise engaged in, the acquisition of or planning, design, construction
and deployment of fiber optic telecommunications services (collectively
"TELECOMMUNICATIONS SERVICES"). 

          (b)  for two (2) years after the termination of this Agreement for any
reason whatsoever;

               (i)   Executive  will not solicit for the provision of
Telecommunication Services in or within a radius of 50 miles of any area where
the Company, or any Affiliated Company, has a franchise or leases or licenses
fiber optic Telecommunication Services, in competition with the Company or any
Affiliated Company, any person who is a customer of the Company or any
Affiliated Company; and

               (ii)  he will not employ or induce or attempt to persuade any
employee of the Company or any Affiliated Company to terminate their employment
relationship in order to enter into competitive employment, or in any way cause,
influence or participate in the employment of any such individual by anyone else
in any business that is competitive with any business then engaged in by the
Company or any Affiliated Company.

     11.  BRIBERY, EXTORTION AND KICKBACKS

          Executive shall not at any time make or promise to make or accept any
payments or transfers of value which has the purpose or effect of public or
commercial bribery, acceptance of or acquiescence in extortion, kickbacks or
other unlawful or


                                          6
<PAGE>

improper means of obtaining or conducting business for the Company.  Executive
shall not at any time agree that he will, in connection with his employment or
in connection with any other business transactions involving the Company, make
or promise to make any payment or transfer anything of value, directly or
indirectly, (i) to any governmental official or employee during (including
employees of government corporations) (ii) to any political party, official of a
political party or candidate (or to an intermediary for payment to any of the
foregoing), (iii) to any officer, director, employee, or representative of any
actual or potential customer of the Company or (iv) to any other person or
entity.  The foregoing will not prohibit normal and customary business
entertainment or the giving of business mementos of nominal value.  In addition,
Executive shall at all times be aware of the requirements and prohibitions of
and be in compliance with the United States Foreign Corrupt Practices Act of
1977.

     12.  OWNERSHIP OF INTELLECTUAL PROPERTY.

          All Inventions (as hereinafter defined), or patents, trademarks,
copyrights, trade secrets or any other rights relating to any of the foregoing,
which have or may have a material importance to the business of the Company and
which are conceived or made by Executive in connection with his employment with
the Company, either alone or with others, are the sole and exclusive property of
the Company whether or not they are conceived or made during work time for the
Company, except to the extent generally known by persons generally knowledgeable
in the fiber optics telecommunications field.

          Executive shall immediately disclose to the Company any and all
Inventions (whether or not patentable) made or conceived by the Executive during
the Term, either alone or in conjunction with others, whether or not made or
conceived at the request or upon the suggestion of the Company, whether or not
resulting from any work done in the course of employment, whether or not reduced
to practice during the term of employment, and whether or not made or conceived
during or outside of the usual hours of employment or upon or not upon any
premises of the Company.

          Executive assigns and will hereafter assign to the Company all present
or future right, title and interest in and to all Inventions referred to above. 
Executive shall not disclose any such Inventions to any third party without the
written consent of the Company.

          At any time and from time to time during and after the Term, on the
request of the Company, without further consideration Executive shall:  (i)
execute specific documents of assignment in favor of the Company, or its
nominee, of any of the Inventions covered hereunder, (ii) execute all papers and
perform all acts the Company considers necessary or advisable for the
preparation, application procurement, maintenance, enforcement and defense of
patent applications and patents of the United States or other jurisdictions of
such Inventions, if applicable, for the perfection or enforcement of any
trademarks, copyrights or trade secrets relating to such Invention, and for the
transfer of any interest the Executive may have in such Inventions; and (iii) 


                                          7
<PAGE>

execute any and all papers and comments which the Company considers to necessary
to vest sole right, title and interest in the Company or its nominee in and to
the above Inventions, patent applications, patents, or any trademakrs or
copyright or applications therefore relating thereto.  Notwithstanding the
foregoing, after termination of employment, Executive shall be entitled to
reasonable compensation for more than incidental time and effort required to be
expended by Executive to fulfill his responsibilities under clause (ii).
Executive shall execute all documents (including those referred to above) and do
all other acts which the Company considers to be necessary to assist in the
preservation of all the Company's interests in such Inventions.

          At the commencement of the Term, Executive will provide to the Company
a complete written list of all Inventions which have been made or conceived
before his employment commences or first reduced to practice by Executive alone
or in conjunction with others prior to employment with the Company. 

          For purposes of this Section 12, "Invention" shall mean (i) any and
all machines, apparatuses, compositions of matter, methods, know-how, processes,
computer programs, designs, configurations, uses thereof, or writings (in any
form or any media) of any kind, discovered, conceived, developed, made or
produced, or any improvement to the same, and will not be limited to the
definition of any invention contained in the United States Patent law; (ii) all
matters subject to copyright protection under United States law; (iii) all
matters subject to trademark protection under the laws of the United States or
those of any state of the United States or under common law of any jurisdiction
within the United States; and (iv) all matters subject to protection as trade
secrets under the laws or common law of any state of the United States or of the
United States.

          The term "Work Product" refers to all work product and
work-in-progress generated, created, or developed by Executive in the course of
employment, regardless of the form or medium in which such Work Product is
embodied, including without limitation electronic form and new media.  All Work
Product will be deemed  work made for hire as defined by the Copyright Act of
1976.  As such, all right, title and interest in and to all Work Product will
vest in and remain with the Company from its inception, and Executive shall
execute all documents and all acts which the Company considers necessary to
assist in the preservation of the Company's interest in such Work Product.

          If a court of competent jurisdiction determines that the Work Product
does not constitute work made for hire, Executive agrees that this Agreement
constitutes a written continuing assignment by the Executive to the Company of
all right, title and interest in and to the Work Product.

     13.  ENFORCEMENT.  It is agreed by the Executive that any breach or
threatened breach by the Executive of any provision of Sections 9, 10, 11 or 12
hereof cannot be remedied solely by damages.  In the event of a breach or
threatened breach by the Executive of any of the provisions of Sections 9, 10,
11 or 12 hereof, the Company or


                                          8
<PAGE>

any Affiliated Company shall be entitled to injunctive relief restraining the
Executive and any business, firm, partnership, individual, corporation or other
entity participating in such breach or attempted breach.  Nothing contained
herein shall be construed to prohibit the Company or any Affiliated Company from
pursuing any other remedies available at law or in equity for such breach or
threatened breach, including, without limitation, the recovery of damages.

     14.  REPRESENTATIONS AND WARRANTIES.  The Executive represents and warrants
to the Company that:

          (a)   The Executive has full power and authority to enter into this
Agreement, and this Agreement has been duly and validly executed and delivered
by the Executive and constitutes the legal, valid and binding obligation of the
Executive, enforceable against the Executive in accordance with its terms;

          (b)   The execution and delivery of this Agreement by the Executive
and his performance hereunder will not violate any provision of law and will not
conflict with or result in a breach of any judgment, decree, order, writ,
injunction, regulation, ordinance or other similar document or instrument of any
court or governmental authority, and will not (with or without the giving of
notice or lapse of time, or both) violate or breach any term or condition of, or
constitute a default under, any agreement, document or instrument to which the
Executive is a party or by which he is bound; and

          (c)   The execution and delivery of this Agreement by the Executive
and his performance hereunder do not require the consent or approval of any
other person or entity.

     15.  NOTICES.  All notices and other communications hereunder shall be in
writing and shall be deemed to have been duly given if delivered by hand,
registered or certified mail (first class postage and fees prepaid, return
receipt requested), telecopier or overnight courier guaranteeing next-day
delivery, as follows:

          (a)  If to the Company, one copy to:

               Metromedia Fiber Network, Inc.
               1 North Lexington Avenue
               White Plains, New York  10601
               Attention:  Chairman
               Telecopier No.:     (914) 421-6777

               with a copy (which shall not constitute notice) to:

               Metromedia Fiber Network, Inc.
               c/o Metromedia Company
               One Meadowlands Plaza, 6th Floor


                                          9
<PAGE>

               East Rutherford, New Jersey  07073
               Attention:  General Counsel
               Telecopier No.:     (201) 531-2803

          (b)  If to the Executive, one copy to:

               Vincent A. Galluccio
               244 Shopping Avenue
               Sarasota, Florida  34237
               Telecopier No.:     (___) _____-______

and/or to such other persons and addresses as any party shall have specified in
writing to the other by notice as aforesaid.

     16   ENTIRE AGREEMENT; AMENDMENT.  This Agreement constitutes the entire
agreement between the Company and the Executive with respect to the subject
matter hereof and supersedes all prior agreements between such parties with
respect to the subject matter hereof.  This Agreement may not be amended,
changed, modified or discharged except by an instrument in writing executed by
or on behalf of the party or parties against whom any amendment, change,
modification or discharge is sought to be enforced.

     17.   WAIVER.  No failure by any party to insist upon the strict
performance of any covenant, duty, agreement or condition of this Agreement or
to exercise any right or remedy consequent upon a breach thereof shall
constitute a waiver of any such breach or of any other covenant, duty, agreement
or condition of this Agreement, any such waiver being made only by a written
instrument executed and delivered by the waiving party.

     18.   ASSIGNABILITY.  This Agreement shall not be assignable by the
Executive and any purported assignment hereof by the Executive shall be null and
void.  This Agreement shall be binding upon, and inure to the benefit of, the
Executive and his heirs, executors, administrators and legal representatives,
and the Company and its successors and assigns.

     19.   SEVERABILITY.  If any of the covenants contained in this Agreement,
including, without limitation, those contained in Section 10 hereof, are
hereafter construed to be invalid or unenforceable in any jurisdiction, the same
shall not affect the remainder of the covenant or covenants or the
enforceability in any other jurisdiction, which shall be given full force and
effect, without regard to the invalid portions or the enforceability in such
other jurisdiction.  If any of the covenants contained in Section 10 hereof are
held to be unenforceable because of the scope thereof, the parties agree that
the court making such determination shall have the power to reduce the duration
and/or area of such provision and, in its reduced form, said provision shall be
enforceable; PROVIDED, HOWEVER, that such court's determination shall not affect
the enforceability of Section 10


                                          10
<PAGE>

hereof in any other jurisdiction.

     20.   GOVERNING LAW.  This Agreement shall be governed by, and construed
and interpreted in accordance with, the laws of the State of New York without
reference to conflict of laws principles.

     21.   CONSENT TO JURISDICTION AND SERVICE OF PROCESS. The parties hereto
irrevocably (a) submit to the exclusive jurisdiction of the courts of the State
of New York or the courts of the United States located in the State of New York,
for the purpose of any suit, action or other proceeding arising out of this
Agreement, and (b) waive to the extent not prohibited by law, and agree not to
assert, by way of motion, as a defense or otherwise, in any such suit, action or
proceeding, any claim that they are not subject to the personal jurisdiction of
the above-named courts, that their property is exempt or immune from attachment
or execution, that any such suit, action or proceeding brought in one of the
above-named courts is brought in an inconvenient forum, that the venue of any
such suit, action or proceeding is improper, or that this Agreement or the
subject matter hereof may not be enforced in or by such court, and (c) waive the
right to a trial by jury in any such suit, action or proceeding.

     The Executive hereby consents to service of process in any such suit,
action or proceeding in any manner permitted by civil practice laws and rules of
the State of New York, and agrees that service of process by registered or
certified mail, return receipt requested, at his address specified in or
pursuant to Section 15 hereof is reasonably calculated to give actual notice.

     22.  PRIOR AGREEMENTS.  The Executive and the Company hereby acknowledge
and agree that the terms and provisions of this Agreement replace and supersede
in all respects the terms and provisions of any prior employment or services
agreement which the Executive may have previously entered into with the Company,
or any of its predecessors in interest or affiliates, and that any such previous
agreement shall be deemed to have no further force or effect upon the execution
and delivery of this Agreement by the Executive and the Company.

                (The remainder of this page intentionally left blank)




                                          11
<PAGE>

     23.   HEADINGS.  The headings contained in this Agreement are for
convenience of reference only and in no way define, limit or describe the scope
or intent of this Agreement or in any way affect this Agreement.

     24.   COUNTERPARTS.  This Agreement may be executed in counterparts, each
of which shall be deemed an original, but all of which together shall constitute
one and the same instrument.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the date first above written.


                              METROMEDIA FIBER NETWORK, INC.


                              By:
                                 ---------------------------
                                 Name:  Howard Finkelstein
                                 Title: President



                              ------------------------------
                              Vincent A. Galluccio












                                          12

<PAGE>
                                                                   Exhibit 10.21


                                 EMPLOYMENT AGREEMENT

     AGREEMENT, dated as of August 31, 1998, by and between METROMEDIA FIBER
NETWORK, INC., a Delaware corporation having its principal offices at 1 North
Lexington Avenue, White Plains, New York  10601 (the "Company"), and Gerard
Benedetto, residing at 9 Pipers Hill Road, Wilton, Connecticut  06897(the
"EXECUTIVE").


                                 W I T N E S S E T H:
                                 - - - - - - - - - - 

     WHEREAS, to insure the continuity of senior management of the Company,
notwithstanding a material change in the ownership or business activities of the
Company,  the Company  and Executive desire to enter into this Agreement on the
terms and conditions hereinafter set forth;  

     WHEREAS, the Company has granted non-qualified stock options to purchase
75,000 shares (the "NQSO's") of the Company's Class A common stock, par value
$.01 per share ("Class A Common Stock"), to Executive under the Company's 1998
Incentive Stock Option Plan (the "Plan") pursuant to the Stock Option Agreement
between the Company and Executive dated of even date herewith (the "Stock Option
Agreement"); and

     WHEREAS, the Executive, as additional consideration for entering into this
Agreement with the Company, has agreed to forego his right to accelerate the
vesting of the NQSO's upon a Change in Control (as such term is defined in the
Plan).

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

     1.   EMPLOYMENT; TERM.

          (a)   The Company hereby employs the Executive, and the Executive
hereby agrees to serve, as Vice President of the Company. 

          (b)   The term (the "Term") of the Executive's employment hereunder
shall commence on August 31, 1998 and shall terminate on January 7, 2002  (the
"EXPIRATION DATE"), unless sooner terminated as provided in paragraph 7 below. 


     2.   DUTIES.

          (a) The Executive agrees to perform his duties and exercise his
authority pursuant to the direction and control of the President and shall
report to the President or the President's designee as and when requested.  The
Executive shall have such powers and duties as assigned or changed by the
President from time to



                                           
<PAGE>

time.  The Executive shall perform his duties diligently, faithfully and to the
best of his ability and in accordance with sound business practices.  

          (b)   The Executive shall devote to the exclusion of other business
activities other than Permitted Activities (as hereinafter defined) all his
business time and attention to his duties and responsibilities hereunder,
subject to paid vacations and holidays as hereinafter set forth in Section 6(b)
of this Agreement.

          (c)  For purposes of this Agreement "Permitted Activities" shall mean
(i) passive business or charitable activities that may, from time to time,
require insubstantial portions of his business time, but which would not,
singularly or in the aggregate, interfere with the devotion of substantially all
his business attention and energies to the affairs of the Company, or his
obligations under this Agreement, or otherwise be inconsistent with his duties
hereunder and (ii) the ownership by the Executive (as the result of open market
purchase) of one (1%) percent or less of any class of capital stock of a
corporation which is regularly traded on a national securities exchange or
over-the-counter on the NASDAQ system. 

     3.   COMPENSATION.

          (a)   During the Term, the Executive shall receive an annual base
salary of  Two Hundred Thousand ($200,000) Dollars (the "BASE SALARY") subject
to required deductions and withholdings as required by law or agreement payable
in accordance with the standard payroll practices of the Company. 

          (b)  In addition to the Base Salary set forth in Section 3(a) hereof,
the Executive shall be entitled to participate in the Company's bonus program
(the "Bonus Plan") which is recommended by the President and is subject to the
approval of the Compensation Committee of the Board of Directors.  The Bonus
Plan is predicated on the Company attaining certain financial and other
objectives.  The Executive shall have an initial target of a bonus of 20% of the
Executive's Base Salary set forth in  Section 3(a) hereof based upon achieving
100% of the Bonus Plan's objectives.  The Bonus Plan is a calendar year plan, as
such, the bonus Executive may receive will be adjusted on the basis of the Term.
For example, since the Term is to commence on August 31, 1998, if all objectives
of the Bonus Plan are achieved the targeted bonus of 20% will be prorated to
$13,479.45 (i.e. $200,000 (.20/365 days)(123 days) = $13,479.45).

          (c) It is understood that nothing contained herein shall prevent the
Company, in its sole and absolute discretion, from at any time increasing the
compensation herein provided to be paid to the Executive, either permanently or
for a limited period, in the event the Company, in its sole and absolute
discretion, shall deem it advisable to do so in order to recognize and fairly
compensate the Executive for the value of his services to the Company; PROVIDED,
HOWEVER, that nothing in this Section 3(c) shall in any manner obligate the
Company to make any such increase or provide any such additional compensation or
benefits to the Executive.


                                          2
<PAGE>

     4.   STOCK OPTIONS.  (a)   In accordance with the terms and conditions set
forth in the Stock Option Agreement, the Compensation Committee of the Board of
Directors granted to Executive under the Plan, non-qualified stock options
("NQSOs") for a total of 75,000 shares of Class A Common Stock bearing an
exercise price of $21.00 per share.   In consideration for entering into this
Agreement, Executive hereby agrees that in the event that there is a Change in
Control (as such term is defined in the Plan) of the Company, the NQSOs granted
to Executive pursuant to the Stock Option Agreement shall continue to vest in
accordance with the vesting schedule set forth in the Stock Option Agreement
and, notwithstanding paragraph 4 of the Stock Option Agreement, shall not
accelerate and shall not be immediately exercisable upon a Change in Control. 

          (b)  Except as specifically provided herein, nothing contained in this
Agreement shall be deemed to modify in any respect the terms, provisions, or
conditions of the Stock Option Agreement and such terms, provisions and
conditions of the Stock Option Agreement shall remain in full force and effect.

     5.   EXPENSES.  The Company shall reimburse the Executive for all
reasonable out-of-pocket business expenses paid or incurred by him in connection
with the performance of his duties and responsibilities hereunder, but payment
shall be made only against a signed, itemized list of such expenses, utilizing
general forms for that purpose established by the Company.  


     6.   ADDITIONAL BENEFITS; VACATIONS; FACILITIES.

          (a)    The Executive shall be entitled to participate in all group
health and insurance programs and all other fringe benefit or retirement plans
or other plans effective generally with respect to senior executives of the
Company.  Nothing herein shall be deemed to require the Company to establish or
maintain any employee benefit plan whatsoever, and the Company shall have the
right, in its sole and absolute discretion, to alter, amend, modify, discontinue
or terminate any and all employee benefit plans at any time.  

          (b)   During the Term, the Executive shall be entitled to the same
paid holidays as are provided to executives of the Company generally and shall
be entitled to take periodic vacations with pay aggregating three weeks per
twelve-month period during the Term consistent with his duties and
responsibilities hereunder and the Company's vacation policy.  

          (c)   The Company shall furnish the Executive with such working
facilities and other services as are suitable to his position and are adequate
for the performance of his duties hereunder.

     7.   TERMINATION OF EMPLOYMENT.  This Agreement may be terminated prior to
the Expiration Date in accordance with the following provisions:


                                          3
<PAGE>

          (a)  In the event of the Executive's death prior to the Expiration
Date, this  Agreement shall automatically terminate.

          (b)  If the Executive shall suffer a Disability (as hereinafter
defined) prior to the Expiration Date, this Agreement may be terminated at the
option of the Company by notice from the Company to the Executive given at any
time after the Executive shall have suffered a Disability.  The term
"DISABILITY" shall mean that the Executive shall be unable for a period of
ninety (90) days or more during the Term, because of a physical or mental
illness or condition, to perform his duties hereunder.  In such event, such
termination shall be effective as of the date on which the Company gives notice
to the Executive that it is terminating his employment hereunder pursuant to
this Section 7(b) without further obligation to Executive other than to pay the
compensation and reimbursement amounts provided for herein prorated to the date
of such termination.

          (c)    In the event that there is a Change in Control (as such term is
defined in the Plan) of the Company and the Executive is requested in connection
therewith to perform his duties hereunder on a regular, full-time basis at a
location further than 75 miles from Executive's current principal office
location, the Executive, in his sole and absolute discretion, may deem this
Agreement to be terminated by the Company without Cause (as hereinafter defined)
and the Executive shall be entitled to receive from the Company the "Termination
Payments" set forth in Section 8 of this Agreement.    

          (d)   This Agreement may be terminated prior to the Expiration Date at
the option of the Company for Cause, effective as of the date on which the
Company gives notice to the Executive that it is terminating his employment
pursuant to this Section 7(d).  The term for "CAUSE" shall mean and include any
of the following events:

               (i)     fraud, misappropriation or embezzlement of funds or
property by the Executive involving the Company or an Affiliated Company (as
hereinafter defined);

               (ii)    the conviction of the Executive in any jurisdiction for
any crime which constitutes a felony, or which constitutes a misdemeanor that
involves fraud, moral turpitude or material loss to the Company or an Affiliated
Company, or their respective businesses or reputations;

               (iii)   the Executive's misconduct in, or neglect of, the
performance of his duties and responsibilities hereunder, or the Executive's
repeated violation of any reasonable specific written directions of the
President of the Company or the President's designee which directions are
consistent with the provisions of this Agreement;

               (iv)    the Executive's breach of the agreements and covenants
set forth in Sections 9, 10, 11 or 12  hereof; or


                                          4
<PAGE>

               (v)     the Executive's material breach of any other provision of
this Agreement which breach continues uncured for five (5) days after written
notice thereof is given to the Executive by the Company or the President of the
Company.

     In the event of the termination of the Executive's employment hereunder for
"Cause", such termination shall be effective as of the date of notice of such
termination and the Company shall have no further obligations whatsoever
hereunder to compensate the Executive pursuant to the terms of this Agreement.

     The term "AFFILIATED COMPANIES" shall mean all entities that directly or
indirectly control, or are controlled by, the Company, all entities that are
under direct or indirect common control with the Company, and all entities in
which the Company has a significant joint venture or other similar interest. 
"CONTROL" and "CONTROLLED" shall mean possession, directly or indirectly, of the
power to direct or cause the direction of the management and policies of a
corporation, partnership or other entity, whether through ownership of voting
securities, by contract or otherwise.

     8.   TERMINATION PAYMENTS.  Upon the termination by the Company of
Executive's employment for any reason other than for Cause, the Executive shall
be entitled to receive from the Company (i) the Executive's unpaid Base Salary
for the remaining Term of Employment under this Agreement, (ii) all previously
earned and accrued entitlements and benefits from the Company and its employee
benefit plans and (iii) an amount equal to the product of the Executive's Base
Salary multiplied by .25.

     9.   CONFIDENTIAL INFORMATION.  The Executive covenants and agrees that:

          (a)   During the Term and thereafter, he will keep secret and retain
in the strictest confidence all information about business and financial matters
(including, without limitation, information relating to costs, profits, budgets
and plans for future development, strategy, methods of operation and marketing
concepts) of the Company and the Affiliated Companies, their respective
employment policies and plans, and any other trade secrets and proprietary
information relating to the Company, the Affiliated Companies or their
respective operations, business and financial affairs, other than information
which is otherwise generally available to the public other than as a result of a
disclosure by the Executive (collectively, the "CONFIDENTIAL INFORMATION"), and,
for such time as the Company or any Affiliated Company is operating, not
disclose any Confidential Information to anyone outside of the Company or an
Affiliated Company, either during or after the term of his employment by the
Company or an Affiliated Company, except (i) in the course of performing his
duties hereunder, (ii) with the Company's express prior written consent or (iii)
as required by law; and

          (b)   The Executive will surrender to the Company within ten (10) days
after the termination of his employment hereunder, or at any time the Company
may so request, all memoranda, notes, records, reports, lists and other
documents containing, describing or relating to Confidential Information,
together with all copies thereof, obtained by him or entrusted to him during the
course of his employment by the


                                          5
<PAGE>

Company or an Affiliated Company or otherwise in his possession at the time of
such termination or request.

     10.  RESTRICTIVE COVENANTS

          Executive covenants and agrees that:

          (a) during the Term for any reason whatsoever he will not compete,
directly or indirectly, with the Company or any Affiliated Company, by
participating in the direct or indirect ownership, management, operation or
control, whether as an officer, director, partner, employee, advisor,
stockholder, investor, consultant, agent, independent contractor, lender or
otherwise, of any corporation, partnership or other entity which owns, acquires
or seeks to acquire or obtain any franchise, lease or license, relating to, or
is otherwise engaged in, the acquisition of or planning, design, construction
and deployment of fiber optic telecommunications services (collectively
"TELECOMMUNICATIONS SERVICES"). 

          (b)  for two (2) years after the termination of this Agreement for any
reason whatsoever;

               (i)  Executive  will not solicit for the provision of
Telecommunication Services in or within a radius of 50 miles of any area where
the Company, or any Affiliated Company, has a franchise or leases or licenses
fiber optic Telecommunication Services, in competition with the Company or any
Affiliated Company, any person who is a customer of the Company or any
Affiliated Company; and

               (ii) he will not employ or induce or attempt to persuade any
employee of the Company or any Affiliated Company to terminate their employment
relationship in order to enter into competitive employment, or in any way cause,
influence or participate in the employment of any such individual by anyone else
in any business that is competitive with any business then engaged in by the
Company or any Affiliated Company.

     11.  BRIBERY, EXTORTION AND KICKBACKS

          Executive shall not at any time make or promise to make or accept any
payments or transfers of value which has the purpose or effect of public or
commercial bribery, acceptance of or acquiescence in extortion, kickbacks or
other unlawful or improper means of obtaining or conducting business for the
Company.  Executive shall not at any time agree that he will, in connection with
his employment or in connection with any other business transactions involving
the Company, make or promise to make any payment or transfer anything of value,
directly or indirectly, (i) to any governmental official or employee during
(including employees of government corporations) (ii) to any political party,
official of a political party or candidate (or to an intermediary for payment


                                          6
<PAGE>

to any of the foregoing), (iii) to any officer, director, employee, or
representative of any actual or potential customer of the Company or (iv) to any
other person or entity.  The foregoing will not prohibit normal and customary
business entertainment or the giving of business mementos of nominal value.  In
addition, Executive shall at all times be aware of the requirements and
prohibitions of and be in compliance with the United States Foreign Corrupt
Practices Act of 1977.

     12.  OWNERSHIP OF INTELLECTUAL PROPERTY.

          All Inventions (as hereinafter defined), or patents, trademarks,
copyrights, trade secrets or any other rights relating to any of the foregoing,
which have or may have a material importance to the business of the Company and
which are conceived or made by Executive in connection with his employment with
the Company, either alone or with others, are the sole and exclusive property of
the Company whether or not they are conceived or made during work time for the
Company, except to the extent generally known by persons generally knowledgeable
in the fiber optics telecommunications field.

          Executive shall immediately disclose to the Company any and all
Inventions (whether or not patentable) made or conceived by the Executive during
the Term, either alone or in conjunction with others, whether or not made or
conceived at the request or upon the suggestion of the Company, whether or not
resulting from any work done in the course of employment, whether or not reduced
to practice during the term of employment, and whether or not made or conceived
during or outside of the usual hours of employment or upon or not upon any
premises of the Company.

          Executive assigns and will hereafter assign to the Company all present
or future right, title and interest in and to all Inventions referred to above. 
Executive shall not disclose any such Inventions to any third party without the
written consent of the Company.

          At any time and from time to time during and after the Term, on the
request of the Company, without further consideration Executive shall:  (i)
execute specific documents of assignment in favor of the Company, or its
nominee, of any of the Inventions covered hereunder, (ii) execute all papers and
perform all acts the Company considers necessary or advisable for the
preparation, application procurement, maintenance, enforcement and defense of
patent applications and patents of the United States or other jurisdictions of
such Inventions, if applicable, for the perfection or enforcement of any
trademarks, copyrights or trade secrets relating to such Invention, and for the
transfer of any interest the Executive may have in such Inventions; and (iii)
execute any and all papers and comments which the Company considers to necessary
to vest sole right, title and interest in the Company or its nominee in and to
the above Inventions, patent applications, patents, or any trademakrs or
copyright or applications therefore relating thereto.  Notwithstanding the
foregoing, after termination of employment, Executive shall be entitled to
reasonable compensation for more than incidental time and effort required to be
expended by Executive to fulfill his


                                          7
<PAGE>

responsibilities under clause (ii). Executive shall execute all documents
(including those referred to above) and do all other acts which the Company
considers to be necessary to assist in the preservation of all the Company's
interests in such Inventions.

     At the commencement of the Term, Executive will provide to the Company a
complete written list of all Inventions which have been made or conceived before
his employment commences or first reduced to practice by Executive alone or in
conjunction with others prior to employment with the Company. 

     For purposes of this Section 12, "Invention" shall mean (i) any and all
machines, apparatuses, compositions of matter, methods, know-how, processes,
computer programs, designs, configurations, uses thereof, or writings (in any
form or any media) of any kind, discovered, conceived, developed, made or
produced, or any improvement to the same, and will not be limited to the
definition of any invention contained in the United States Patent law; (ii) all
matters subject to copyright protection under United States law; (iii) all
matters subject to trademark protection under the laws of the United States or
those of any state of the United States or under common law of any jurisdiction
within the United States; and (iv) all matters subject to protection as trade
secrets under the laws or common law of any state of the United States or of the
United States.

     The term "Work Product" refers to all work product and work-in-progress
generated, created, or developed by Executive in the course of employment,
regardless of the form or medium in which such Work Product is embodied,
including without limitation electronic form and new media.  All Work Product
will be deemed  work made for hire as defined by the Copyright Act of 1976.  As
such, all right, title and interest in and to all Work Product will vest in and
remain with the Company from its inception, and Executive shall execute all
documents and all acts which the Company considers necessary to assist in the
preservation of the Company's interest in such Work Product.

     If a court of competent jurisdiction determines that the Work Product does
not constitute work made for hire, Executive agrees that this Agreement
constitutes a written continuing assignment by the Executive to the Company of
all right, title and interest in and to the Work Product.

     13.  ENFORCEMENT.  It is agreed by the Executive that any breach or
threatened breach by the Executive of any provision of Sections 9, 10, 11 or 12
hereof cannot be remedied solely by damages.  In the event of a breach or
threatened breach by the Executive of any of the provisions of Sections 9, 10,
11 or 12 hereof, the Company or any Affiliated Company shall be entitled to
injunctive relief restraining the Executive and any business, firm, partnership,
individual, corporation or other entity participating in such breach or
attempted breach.  Nothing contained herein shall be construed to prohibit the
Company or any Affiliated Company from pursuing any other remedies available at
law or in equity for such breach or threatened breach, including, without
limitation, the recovery of damages.


                                          8
<PAGE>

     14.  REPRESENTATIONS AND WARRANTIES.  The Executive represents and warrants
to the Company that:

          (a)   The Executive has full power and authority to enter into this
Agreement, and this Agreement has been duly and validly executed and delivered
by the Executive and constitutes the legal, valid and binding obligation of the
Executive, enforceable against the Executive in accordance with its terms;

          (b)   The execution and delivery of this Agreement by the Executive
and his performance hereunder will not violate any provision of law and will not
conflict with or result in a breach of any judgment, decree, order, writ,
injunction, regulation, ordinance or other similar document or instrument of any
court or governmental authority, and will not (with or without the giving of
notice or lapse of time, or both) violate or breach any term or condition of, or
constitute a default under, any agreement, document or instrument to which the
Executive is a party or by which he is bound; and

          (c)   The execution and delivery of this Agreement by the Executive
and his performance hereunder do not require the consent or approval of any
other person or entity.

     15.  NOTICES.  All notices and other communications hereunder shall be in
writing and shall be deemed to have been duly given if delivered by hand,
registered or certified mail (first class postage and fees prepaid, return
receipt requested), telecopier or overnight courier guaranteeing next-day
delivery, as follows:

          (a)  If to the Company, one copy to:

               Metromedia Fiber Network, Inc.
               1 North Lexington Avenue
               White Plains, New York  10601
               Attention:  Chairman
               Telecopier No.:     (914) 421-6777

               with a copy (which shall not constitute notice) to:

               Metromedia Fiber Network, Inc.
               c/o Metromedia Company
               One Meadowlands Plaza, 6th Floor
               East Rutherford, New Jersey  07073
               Attention:  General Counsel
               Telecopier No.:     (201) 531-2803

          (b)  If to the Executive, one copy to:


                                          9
<PAGE>

               Gerard Benedetto
               9 Pipers Hill Road
               Wilton, Connecticut  06897
               Telecopier No.:     (___) _____-______

and/or to such other persons and addresses as any party shall have specified in
writing to the other by notice as aforesaid.

     16   ENTIRE AGREEMENT; AMENDMENT.  This Agreement constitutes the entire
agreement between the Company and the Executive with respect to the subject
matter hereof and supersedes all prior agreements between such parties with
respect to the subject matter hereof.  This Agreement may not be amended,
changed, modified or discharged except by an instrument in writing executed by
or on behalf of the party or parties against whom any amendment, change,
modification or discharge is sought to be enforced.

     17.   WAIVER.  No failure by any party to insist upon the strict
performance of any covenant, duty, agreement or condition of this Agreement or
to exercise any right or remedy consequent upon a breach thereof shall
constitute a waiver of any such breach or of any other covenant, duty, agreement
or condition of this Agreement, any such waiver being made only by a written
instrument executed and delivered by the waiving party.

     18.   ASSIGNABILITY.  This Agreement shall not be assignable by the
Executive and any purported assignment hereof by the Executive shall be null and
void.  This Agreement shall be binding upon, and inure to the benefit of, the
Executive and his heirs, executors, administrators and legal representatives,
and the Company and its successors and assigns.

     19.   SEVERABILITY.  If any of the covenants contained in this Agreement,
including, without limitation, those contained in Section 10 hereof, are
hereafter construed to be invalid or unenforceable in any jurisdiction, the same
shall not affect the remainder of the covenant or covenants or the
enforceability in any other jurisdiction, which shall be given full force and
effect, without regard to the invalid portions or the enforceability in such
other jurisdiction.  If any of the covenants contained in Section 10 hereof are
held to be unenforceable because of the scope thereof, the parties agree that
the court making such determination shall have the power to reduce the duration
and/or area of such provision and, in its reduced form, said provision shall be
enforceable; PROVIDED, HOWEVER, that such court's determination shall not affect
the enforceability of Section 10 hereof in any other jurisdiction.

     20.   GOVERNING LAW.  This Agreement shall be governed by, and construed
and interpreted in accordance with, the laws of the State of New York without
reference to conflict of laws principles.



                                          10
<PAGE>

     21.   CONSENT TO JURISDICTION AND SERVICE OF PROCESS. The parties hereto
irrevocably (a) submit to the exclusive jurisdiction of the courts of the State
of New York or the courts of the United States located in the State of New York,
for the purpose of any suit, action or other proceeding arising out of this
Agreement, and (b) waive to the extent not prohibited by law, and agree not to
assert, by way of motion, as a defense or otherwise, in any such suit, action or
proceeding, any claim that they are not subject to the personal jurisdiction of
the above-named courts, that their property is exempt or immune from attachment
or execution, that any such suit, action or proceeding brought in one of the
above-named courts is brought in an inconvenient forum, that the venue of any
such suit, action or proceeding is improper, or that this Agreement or the
subject matter hereof may not be enforced in or by such court, and (c) waive the
right to a trial by jury in any such suit, action or proceeding.

     The Executive hereby consents to service of process in any such suit,
action or proceeding in any manner permitted by civil practice laws and rules of
the State of New York, and agrees that service of process by registered or
certified mail, return receipt requested, at his address specified in or
pursuant to Section 15 hereof is reasonably calculated to give actual notice.

     22.  PRIOR AGREEMENTS.  The Executive and the Company hereby acknowledge
and agree that the terms and provisions of this Agreement replace and supersede
in all respects the terms and provisions of any prior employment or services
agreement which the Executive may have previously entered into with the Company,
or any of its predecessors in interest or affiliates, and that any such previous
agreement shall be deemed to have no further force or effect upon the execution
and delivery of this Agreement by the Executive and the Company.


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                                          11
<PAGE>

     23.   HEADINGS.  The headings contained in this Agreement are for
convenience of reference only and in no way define, limit or describe the scope
or intent of this Agreement or in any way affect this Agreement.

     24.   Counterparts.  This Agreement may be executed in counterparts, each
of which shall be deemed an original, but all of which together shall constitute
one and the same instrument.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the date first above written.


                                   METROMEDIA FIBER NETWORK, INC.


                                   By:
                                      ---------------------------
                                      Name:  Howard Finkelstein
                                      Title: President



                                   ------------------------------
                                   Gerard Benedetto




                                          12

<PAGE>
                                                                   Exhibit 10.22


                                 EMPLOYMENT AGREEMENT

AGREEMENT, dated as of August 31, 1998, by and between METROMEDIA FIBER NETWORK,
INC., a Delaware corporation having its principal offices at 1 North Lexington
Avenue, White Plains, New York  10601 (the "Company"), and Nicholas Tanzi,
residing at 12 Locust Lane, Ringwood, New Jersey  07456 (the "EXECUTIVE").

                                 W I T N E S S E T H:
                                 - - - - - - - - - - 

     WHEREAS, to insure the continuity of senior management of the Company,
notwithstanding a material change in the ownership or business activities of the
Company,  the Company  and Executive desire to enter into this Agreement on the
terms and conditions hereinafter set forth;  

     WHEREAS, the Company has granted non-qualified stock options to purchase
75,000 shares (the "NQSO's") of the Company's Class A common stock, par value
$.01 per share ("Class A Common Stock"), to Executive under the Company's 1998
Incentive Stock Option Plan (the "Plan") pursuant to the Stock Option Agreement
between the Company and Executive dated of even date herewith (the "Stock Option
Agreement"); and

     WHEREAS, the Executive, as additional consideration for entering into this
Agreement with the Company, has agreed to forego his right to accelerate the
vesting of the NQSO's upon a Change in Control (as such term is defined in the
Plan).

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

     1.   EMPLOYMENT; TERM.

          (a)   The Company hereby employs the Executive, and the Executive
hereby agrees to serve, as Vice President of the Company. 

          (b)   The term (the "Initial Term") of the Executive's employment
hereunder shall commence on August 31, 1998 and shall terminate on September 1,
2000 (the "EXPIRATION DATE"), unless sooner terminated as provided in paragraph
7 below.

     2.   DUTIES.

          (a) The Executive agrees to perform his duties and exercise his
authority pursuant to the direction and control of the President and shall
report to the President or the President's designee as and when requested.  The
Executive shall


                                           
<PAGE>

have such powers and duties as assigned or changed by the President from time to
time.  The Executive shall perform his duties diligently, faithfully and to the
best of his ability and in accordance with sound business practices.  

          (b)   The Executive shall devote to the exclusion of other business
activities other than Permitted Activities (as hereinafter defined) all his
business time and attention to his duties and responsibilities hereunder,
subject to paid vacations and holidays as hereinafter set forth in Section 6(b)
of this Agreement.

          (c)  For purposes of this Agreement "Permitted Activities" shall mean
(i) passive business or charitable activities that may, from time to time,
require insubstantial portions of his business time, but which would not,
singularly or in the aggregate, interfere with the devotion of substantially all
his business attention and energies to the affairs of the Company, or his
obligations under this Agreement, or otherwise be inconsistent with his duties
hereunder and (ii) the ownership by the Executive (as the result of open market
purchase) of one (1%) percent or less of any class of capital stock of a
corporation which is regularly traded on a national securities exchange or
over-the-counter on the NASDAQ system. 

     3.   COMPENSATION.

          (a)   During the Term, the Executive shall receive an annual base
salary of One Hundred Seventy Five Thousand ($175,000) Dollars (the "BASE
SALARY") subject to required deductions and withholdings as required by law or
agreement payable in accordance with the standard payroll practices of the
Company. 

          (b)  In addition to the Base Salary set forth in Section 3(a) hereof,
the Executive shall be entitled to participate in the Company's bonus program
(the "Bonus Plan") which is recommended by the President and is subject to the
approval of the Compensation Committee of the Board of Directors.  The Bonus
Plan is predicated on the Company attaining certain financial and other
objectives.  The Executive shall have an initial target of a bonus of 40% of the
Executive's Base Salary set forth in  Section 3(a) hereof based upon achieving
100% of the Bonus Plan's objectives. The Bonus Plan is a calendar year plan, as
such, the bonus Executive may receive will be adjusted on the basis of the Term.
For example, since the Term is to commence on August 31, 1998, if all objectives
of the Bonus Plan are achieved the targeted bonus of 40% will be prorated to
$23,589.04 (i.e. $175,000(.40/365 days)(123 days) = $23,589.04).

          (c) It is understood that nothing contained herein shall prevent the
Company, in its sole and absolute discretion, from at any time increasing the
compensation herein provided to be paid to the Executive, either permanently or
for a limited period, in the event the Company, in its sole and absolute
discretion, shall deem it advisable to do so in order to recognize and fairly
compensate the Executive for the value of his services to the Company; PROVIDED,
HOWEVER, that nothing in this Section 3(c) shall in any manner obligate the
Company to make any such increase or provide any such additional compensation or
benefits to the Executive.


                                          2
<PAGE>

     4.   STOCK OPTIONS.  (a)   In accordance with the terms and conditions set
forth in the Stock Option Agreement, the Compensation Committee of the Board of
Directors granted to Executive under the Plan, non-qualified stock options
("NQSOs") for a total of 75,000 shares of Class A Common Stock bearing an
exercise price of $21.00 per share.   In consideration for entering into this
Agreement, Executive hereby agrees that in the event that there is a Change in
Control (as such term is defined in the Plan) of the Company, the NQSOs granted
to Executive pursuant to the Stock Option Agreement shall continue to vest in
accordance with the vesting schedule set forth in the Stock Option Agreement
and, notwithstanding paragraph 4 of the Stock Option Agreement, shall not
accelerate and shall not be immediately exercisable upon a Change in Control. 

          (b)  Except as specifically provided herein, nothing contained in this
Agreement shall be deemed to modify in any respect the terms, provisions, or
conditions of the Stock Option Agreement and such terms, provisions and
conditions of the Stock Option Agreement shall remain in full force and effect. 

     5.   EXPENSES.  The Company shall reimburse the Executive for all
reasonable out-of-pocket business expenses paid or incurred by him in connection
with the performance of his duties and responsibilities hereunder, but payment
shall be made only against a signed, itemized list of such expenses, utilizing
general forms for that purpose established by the Company.  


     6.   ADDITIONAL BENEFITS; VACATIONS; FACILITIES.

          (a)    The Executive shall be entitled to participate in all group
health and insurance programs and all other fringe benefit or retirement plans
or other plans effective generally with respect to senior executives of the
Company.  Nothing herein shall be deemed to require the Company to establish or
maintain any employee benefit plan whatsoever, and the Company shall have the
right, in its sole and absolute discretion, to alter, amend, modify, discontinue
or terminate any and all employee benefit plans at any time.  

          (b)   During the Term, the Executive shall be entitled to the same
paid holidays as are provided to executives of the Company generally and shall
be entitled to take periodic vacations with pay aggregating three weeks per
twelve-month period during the Term consistent with his duties and
responsibilities hereunder and the Company's vacation policy.  

          (c)   The Company shall furnish the Executive with such working
facilities and other services as are suitable to his position and are adequate
for the performance of his duties hereunder.

     7.   TERMINATION OF EMPLOYMENT.  This Agreement may be terminated prior to
the Expiration Date in accordance with the following provisions:


                                          3
<PAGE>

          (a)  In the event of the Executive's death prior to the Expiration
Date, this Agreement shall automatically terminate.

          (b)  If the Executive shall suffer a Disability (as hereinafter
defined) prior to the Expiration Date, this Agreement may be terminated at the
option of the Company by notice from the Company to the Executive given at any
time after the Executive shall have suffered a Disability.  The term
"DISABILITY" shall mean that the Executive shall be unable for a period of
ninety (90) days or more during the Term, because of a physical or mental
illness or condition, to perform his duties hereunder.  In such event, such
termination shall be effective as of the date on which the Company gives notice
to the Executive that it is terminating his employment hereunder pursuant to
this Section 7(b) without further obligation to Executive other than to pay the
compensation and reimbursement amounts provided for herein prorated to the date
of such termination.

          (c)  In the event that there is a Change in Control (as such term is
defined in the Plan) of the Company and the Executive is requested in connection
therewith to perform his duties hereunder on a regular, full-time basis at a
location further than 75 miles from Executive's current principal office
location, the Executive, in his sole and absolute discretion, may deem this
Agreement to be terminated by the Company without Cause (as hereinafter defined)
and the Executive shall be entitled to receive from the Company the "Termination
Payments" set forth in Section 8 of this Agreement.    

          (d)  This Agreement may be terminated prior to the Expiration Date at
the option of the Company for Cause, effective as of the date on which the
Company gives notice to the Executive that it is terminating his employment
pursuant to this Section 7(d).  The term for "CAUSE" shall mean and include any
of the following events:

               (i)   fraud, misappropriation or embezzlement of funds or
property by the Executive involving the Company or an Affiliated Company (as
hereinafter defined);

               (ii)  the conviction of the Executive in any jurisdiction for any
crime which constitutes a felony, or which constitutes a misdemeanor that
involves fraud, moral turpitude or material loss to the Company or an Affiliated
Company, or their respective businesses or reputations;

               (iii) the Executive's misconduct in, or neglect of, the
performance of his duties and responsibilities hereunder, or the Executive's
repeated violation of any reasonable specific written directions of the
President of the Company or the President's designee which directions are
consistent with the provisions of this Agreement;

               (iv)  the Executive's breach of the agreements and covenants set
forth in Sections 9, 10, 11 or 12  hereof; or


                                          4
<PAGE>

               (v)   the Executive's material breach of any other provision of
this Agreement which breach continues uncured for five (5) days after written
notice thereof is given to the Executive by the Company or the President of the
Company.

     In the event of the termination of the Executive's employment hereunder for
"Cause", such termination shall be effective as of the date of notice of such
termination and the Company shall have no further obligations whatsoever
hereunder to compensate the Executive pursuant to the terms of this Agreement.

     The term "AFFILIATED COMPANIES" shall mean all entities that directly or
indirectly control, or are controlled by, the Company, all entities that are
under direct or indirect common control with the Company, and all entities in
which the Company has a significant joint venture or other similar interest. 
"CONTROL" and "CONTROLLED" shall mean possession, directly or indirectly, of the
power to direct or cause the direction of the management and policies of a
corporation, partnership or other entity, whether through ownership of voting
securities, by contract or otherwise.

     8.   TERMINATION PAYMENTS.  Upon the termination by the Company of
Executive's employment for any reason other than for Cause, the Executive shall
be entitled to receive from the Company (i) the Executive's unpaid Base Salary
for the remaining Term of Employment under this Agreement, (ii) all previously
earned and accrued entitlements and benefits from the Company and its employee
benefit plans and (iii) an amount equal to the product of the Executive's Base
Salary multiplied by .25.

     9.   CONFIDENTIAL INFORMATION.  The Executive covenants and agrees that:

          (a)   During the Term and thereafter, he will keep secret and retain
in the strictest confidence all information about business and financial matters
(including, without limitation, information relating to costs, profits, budgets
and plans for future development, strategy, methods of operation and marketing
concepts) of the Company and the Affiliated Companies, their respective
employment policies and plans, and any other trade secrets and proprietary
information relating to the Company, the Affiliated Companies or their
respective operations, business and financial affairs, other than information
which is otherwise generally available to the public other than as a result of a
disclosure by the Executive (collectively, the "CONFIDENTIAL INFORMATION"), and,
for such time as the Company or any Affiliated Company is operating, not
disclose any Confidential Information to anyone outside of the Company or an
Affiliated Company, either during or after the term of his employment by the
Company or an Affiliated Company, except (i) in the course of performing his
duties hereunder, (ii) with the Company's express prior written consent or (iii)
as required by law; and

          (b)   The Executive will surrender to the Company within ten (10) days
after the termination of his employment hereunder, or at any time the Company
may so request, all memoranda, notes, records, reports, lists and other
documents containing, describing or relating to Confidential Information,
together with all copies


                                          5
<PAGE>

thereof, obtained by him or entrusted to him during the course of his employment
by the Company or an Affiliated Company or otherwise in his possession at the
time of such termination or request.

     10.  RESTRICTIVE COVENANTS

          Executive covenants and agrees that:

          (a) during the Term for any reason whatsoever he will not compete,
directly or indirectly, with the Company or any Affiliated Company, by
participating in the direct or indirect ownership, management, operation or
control, whether as an officer, director, partner, employee, advisor,
stockholder, investor, consultant, agent, independent contractor, lender or
otherwise, of any corporation, partnership or other entity which owns, acquires
or seeks to acquire or obtain any franchise, lease or license, relating to, or
is otherwise engaged in, the acquisition of or planning, design, construction
and deployment of fiber optic telecommunications services (such acquisition,
planning, design, construction and deployment are collectively referred to
herein as "TELECOMMUNICATIONS SERVICES"). 

          (b) for two (2) years after the termination of this Agreement (the
"Post-Employment Non-Compete Period")  for any reason whatsoever;

               (i)    Executive  will not solicit for the provision of
     Telecommunication Services in or within a radius of 50 miles of any area
     where the Company, or any Affiliated Company, has a franchise or leases or
     licenses fiber optic Telecommunication Services, in competition with the
     Company or any Affiliated Company, any person who is a customer of the
     Company or any Affiliated Company;

               (ii)   Nothing in the foregoing clause (i) shall preclude
     Executive during the Post-Employment Non-Compete Period from soliciting to
     any person whether or not such person is a customer of the Company or any
     Affiliated Company for the provision of telephone services of whatever type
     (i.e., long distance, local and the like) PROVIDED, HOWEVER, that such
     services do not include Telecommunication Services as defined in Section
     10(a) above; and

               (iii)  Executive  will not employ or induce or attempt to
     persuade any employee of the Company or any Affiliated Company to terminate
     their employment relationship in order to enter into competitive
     employment, or in any way cause, influence or participate in the employment
     of any such individual by anyone else in any business that is competitive
     with any business then engaged in by the Company or any Affiliated Company.

     11.  BRIBERY, EXTORTION AND KICKBACKS

          Executive shall not at any time make or promise to make or accept any 


                                          6
<PAGE>

payments or transfers of value which has the purpose or effect of public or
commercial bribery, acceptance of or acquiescence in extortion, kickbacks or
other unlawful or improper means of obtaining or conducting business for the
Company.  Executive shall not at any time agree that he will, in connection with
his employment or in connection with any other business transactions involving
the Company, make or promise to make any payment or transfer anything of value,
directly or indirectly, (i) to any governmental official or employee during
(including employees of government corporations) (ii) to any political party,
official of a political party or candidate (or to an intermediary for payment to
any of the foregoing), (iii) to any officer, director, employee, or
representative of any actual or potential customer of the Company or (iv) to any
other person or entity.  The foregoing will not prohibit normal and customary
business entertainment or the giving of business mementos of nominal value.  In
addition, Executive shall at all times be aware of the requirements and
prohibitions of and be in compliance with the United States Foreign Corrupt
Practices Act of 1977.

     12.  OWNERSHIP OF INTELLECTUAL PROPERTY.

          All Inventions (as hereinafter defined), or patents, trademarks,
copyrights, trade secrets or any other rights relating to any of the foregoing,
which have or may have a material importance to the business of the Company and
which are conceived or made by Executive in connection with his employment with
the Company, either alone or with others, are the sole and exclusive property of
the Company whether or not they are conceived or made during work time for the
Company, except to the extent generally known by persons generally knowledgeable
in the fiber optics telecommunications field.

          Executive shall immediately disclose to the Company any and all
Inventions (whether or not patentable) made or conceived by the Executive during
the Term, either alone or in conjunction with others, whether or not made or
conceived at the request or upon the suggestion of the Company, whether or not
resulting from any work done in the course of employment, whether or not reduced
to practice during the term of employment, and whether or not made or conceived
during or outside of the usual hours of employment or upon or not upon any
premises of the Company.

          Executive assigns and will hereafter assign to the Company all present
or future right, title and interest in and to all Inventions referred to above. 
Executive shall not disclose any such Inventions to any third party without the
written consent of the Company.

          At any time and from time to time during and after the Term, on the
request of the Company, without further consideration Executive shall:  (i)
execute specific documents of assignment in favor of the Company, or its
nominee, of any of the Inventions covered hereunder, (ii) execute all papers and
perform all acts the Company considers necessary or advisable for the
preparation, application procurement, maintenance, enforcement and defense of
patent applications and patents of the United States or other jurisdictions of
such Inventions, if applicable, for the perfection or


                                          7
<PAGE>

enforcement of any trademarks, copyrights or trade secrets relating to such
Invention, and for the transfer of any interest the Executive may have in such
Inventions; and (iii) execute any and all papers and comments which the Company
considers to necessary to vest sole right, title and interest in the Company or
its nominee in and to the above Inventions, patent applications, patents, or any
trademakrs or copyright or applications therefore relating thereto. 
Notwithstanding the foregoing, after termination of employment, Executive shall
be entitled to reasonable compensation for more than incidental time and effort
required to be expended by Executive to fulfill his responsibilities under
clause (ii). Executive shall execute all documents (including those referred to
above) and do all other acts which the Company considers to be necessary to
assist in the preservation of all the Company's interests in such Inventions.

     At the commencement of the Term, Executive will provide to the Company a
complete written list of all Inventions which have been made or conceived before
his employment commences or first reduced to practice by Executive alone or in
conjunction with others prior to employment with the Company. 


     For purposes of this Section 12, "Invention" shall mean (i) any and all
machines, apparatuses, compositions of matter, methods, know-how, processes,
computer programs, designs, configurations, uses thereof, or writings (in any
form or any media) of any kind, discovered, conceived, developed, made or
produced, or any improvement to the same, and will not be limited to the
definition of any invention contained in the United States Patent law; (ii) all
matters subject to copyright protection under United States law; (iii) all
matters subject to trademark protection under the laws of the United States or
those of any state of the United States or under common law of any jurisdiction
within the United States; and (iv) all matters subject to protection as trade
secrets under the laws or common law of any state of the United States or of the
United States.

     The term "Work Product" refers to all work product and work-in-progress
generated, created, or developed by Executive in the course of employment,
regardless of the form or medium in which such Work Product is embodied,
including without limitation electronic form and new media.  All Work Product
will be deemed  work made for hire as defined by the Copyright Act of 1976.  As
such, all right, title and interest in and to all Work Product will vest in and
remain with the Company from its inception, and Executive shall execute all
documents and all acts which the Company considers necessary to assist in the
preservation of the Company's interest in such Work Product.

     If a court of competent jurisdiction determines that the Work Product does
not constitute work made for hire, Executive agrees that this Agreement
constitutes a written continuing assignment by the Executive to the Company of
all right, title and interest in and to the Work Product.

     13.  ENFORCEMENT.  It is agreed by the Executive that any breach or
threatened breach by the Executive of any provision of Sections 9, 10, 11 or 12
hereof cannot be


                                          8
<PAGE>

remedied solely by damages.  In the event of a breach or threatened breach by
the Executive of any of the provisions of Sections 9, 10, 11 or 12 hereof, the
Company or any Affiliated Company shall be entitled to injunctive relief
restraining the Executive and any business, firm, partnership, individual,
corporation or other entity participating in such breach or attempted breach. 
Nothing contained herein shall be construed to prohibit the Company or any
Affiliated Company from pursuing any other remedies available at law or in
equity for such breach or threatened breach, including, without limitation, the
recovery of damages.

     14.  REPRESENTATIONS AND WARRANTIES.  The Executive represents and warrants
to the Company that:

          (a)   The Executive has full power and authority to enter into this
Agreement, and this Agreement has been duly and validly executed and delivered
by the Executive and constitutes the legal, valid and binding obligation of the
Executive, enforceable against the Executive in accordance with its terms;

          (b)   The execution and delivery of this Agreement by the Executive
and his performance hereunder will not violate any provision of law and will not
conflict with or result in a breach of any judgment, decree, order, writ,
injunction, regulation, ordinance or other similar document or instrument of any
court or governmental authority, and will not (with or without the giving of
notice or lapse of time, or both) violate or breach any term or condition of, or
constitute a default under, any
agreement, document or instrument to which the Executive is a party or by which
he is bound; and

          (c)   The execution and delivery of this Agreement by the Executive
and his performance hereunder do not require the consent or approval of any
other person or entity.

     15.  NOTICES.  All notices and other communications hereunder shall be in
writing and shall be deemed to have been duly given if delivered by hand,
registered or certified mail (first class postage and fees prepaid, return
receipt requested), telecopier or overnight courier guaranteeing next-day
delivery, as follows:

          (a)  If to the Company, one copy to:

               Metromedia Fiber Network, Inc.
               1 North Lexington Avenue
               White Plains, New York  10601
               Attention:  Chairman
               Telecopier No.:     (914) 421-6777

               with a copy (which shall not constitute notice) to:


                                          9
<PAGE>

               Metromedia Fiber Network, Inc.
               c/o Metromedia Company
               One Meadowlands Plaza, 6th Floor
               East Rutherford, New Jersey  07073
               Attention:  General Counsel
               Telecopier No.:     (201) 531-2803

          (b)  If to the Executive, one copy to:

               Nicholas Tanzi
               12 Locust Lane
               Ringwood, New Jersey  07456
               Telecopier No.:     (___) ___-____

and/or to such other persons and addresses as any party shall have specified in
writing to the other by notice as aforesaid.

     16.  ENTIRE AGREEMENT; AMENDMENT.  This Agreement constitutes the entire
agreement between the Company and the Executive with respect to the subject
matter hereof and supersedes all prior agreements between such parties with
respect to the subject matter hereof.  This Agreement may not be amended,
changed, modified or discharged except by an instrument in writing executed by
or on behalf of the party or parties against whom any amendment, change,
modification or discharge is sought to be enforced.

     17.  WAIVER.  No failure by any party to insist upon the strict performance
of any covenant, duty, agreement or condition of this Agreement or to exercise
any right or remedy consequent upon a breach thereof shall constitute a waiver
of any such breach or of any other covenant, duty, agreement or condition of
this Agreement, any such waiver being made only by a written instrument executed
and delivered by the waiving party.

     18.  ASSIGNABILITY.  This Agreement shall not be assignable by the
Executive and any purported assignment hereof by the Executive shall be null and
void.  This Agreement shall be binding upon, and inure to the benefit of, the
Executive and his heirs, executors, administrators and legal representatives,
and the Company and its successors and assigns.

     19.  SEVERABILITY.  If any of the covenants contained in this Agreement,
including, without limitation, those contained in Section 10 hereof, are
hereafter construed to be invalid or unenforceable in any jurisdiction, the same
shall not affect the remainder of the covenant or covenants or the
enforceability in any other jurisdiction, which shall be given full force and
effect, without regard to the invalid portions or the enforceability in such
other jurisdiction.  If any of the covenants contained in Section 10 hereof are
held to be unenforceable because of the scope thereof, the parties agree that
the court


                                          10
<PAGE>

making such determination shall have the power to reduce the duration and/or
area of such provision and, in its reduced form, said provision shall be
enforceable; PROVIDED, HOWEVER, that such court's determination shall not affect
the enforceability of Section 10 hereof in any other jurisdiction.

     20.   GOVERNING LAW.  This Agreement shall be governed by, and construed
and interpreted in accordance with, the laws of the State of New York without
reference to conflict of laws principles.

     21.   CONSENT TO JURISDICTION AND SERVICE OF PROCESS. The parties hereto
irrevocably (a) submit to the exclusive jurisdiction of the courts of the State
of New York or the courts of the United States located in the State of New York,
for the purpose of any suit, action or other proceeding arising out of this
Agreement, and (b) waive to the extent not prohibited by law, and agree not to
assert, by way of motion, as a defense or otherwise, in any such suit, action or
proceeding, any claim that they are not subject to the personal jurisdiction of
the above-named courts, that their property is exempt or immune from attachment
or execution, that any such suit, action or proceeding brought in one of the
above-named courts is brought in an inconvenient forum, that the venue of any
such suit, action or proceeding is improper, or that this Agreement or the
subject matter hereof may not be enforced in or by such court, and (c) waive the
right to a trial by jury in any such suit, action or proceeding.

     The Executive hereby consents to service of process in any such suit,
action or proceeding in any manner permitted by civil practice laws and rules of
the State of New York, and agrees that service of process by registered or
certified mail, return receipt requested, at his address specified in or
pursuant to Section 15 hereof is reasonably calculated to give actual notice.

     22.  PRIOR AGREEMENTS.  The Executive and the Company hereby acknowledge
and agree that the terms and provisions of this Agreement replace and supersede
in all respects the terms and provisions of any prior employment or services
agreement which the Executive may have previously entered into with the Company,
or any of its predecessors in interest or affiliates, and that any such previous
agreement shall be deemed to have no further force or effect upon the execution
and delivery of this Agreement by the Executive and the Company.


                (The remainder of this page intentionally left blank)















                                          11
<PAGE>



     23.   HEADINGS.  The headings contained in this Agreement are for
convenience of reference only and in no way define, limit or describe the scope
or intent of this Agreement or in any way affect this Agreement.

     24.   COUNTERPARTS.  This Agreement may be executed in counterparts, each
of which shall be deemed an original, but all of which together shall constitute
one and the same instrument.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the date first above written.


                              METROMEDIA FIBER NETWORK, INC.


                              By:
                                 ---------------------------
                                 Name:  Howard Finkelstein
                                 Title: President




                              ------------------------------
                              Nicholas Tanzi 






                                          12

<PAGE>



                                                             EXHIBIT 12.1




                                      METROMEDIA FIBER NETWORK, INC

                                 STATEMENT REGARDING COMPUTATION OF RATIOS
                                                   (000's)

<TABLE>

<S>                                    <C>           <C>       <C>       <C>      <C>       <C>      <C>

                                Period from 4/8/93                                          Nine Months Ended
                                (date of inception)           Year Ended December 31,          September 30,
                                  to 12/31/1993               ----------------------        ------------------
                                                     1994     1995      1996       1997      1997     1998
                                 ------------------  ----     ----      ----       ----      ----     ----
Pre-tax loss from continuing
    operations                              (188)    (874)   (4,319)  (10,359)   (26,260)  (24,556)   1,892

Fixed charges:

Interest charges                               0        0       327     3,561        741       512       16
Rent expense                                   0        0        49        53         89        88      208

Total fixed charges                            0        0       376     3,614        830       600      224

Earnings before income taxes
    and fixed charges                       (188)    (874)   (3,943)  ( 6,745)   (25,430)  (23,956)   2,116

Ratio of earnings to fixed
    charges (n/a=negative)                   n/a      n/a      n/a       n/a        n/a       n/a      9.45

</TABLE>

<PAGE>
                                                                    EXHIBIT 23.1
 
                        CONSENT OF INDEPENDENT AUDITORS
 
   
We consent to the references to our firm under the captions "Summary
Consolidated Financial Data," "Selected Consolidated Financial Data" and
"Experts" and to the use of our report dated March 16, 1998 relating to the 1997
and 1996 financial statements of Metromedia Fiber Network, Inc. in Amendment No.
1 to the Registration Statement (Form S-4) and related Prospectus for the
registration of $650,000,000 of its 10% Series B Senior Notes due 2008.
    
 
                                          /s/ Ernst & Young LLP
                                          Ernst & Young LLP
 
   
New York, New York
February 10, 1999
    

<PAGE>
                                                                    EXHIBIT 23.2
 
                        CONSENT OF INDEPENDENT AUDITORS
 
   
    We consent to the reference to our firm under the captions "Selected
Consolidated Financial Data", "Summary Consolidated Financial Data" and
"Experts" and the use of our report dated June 26, 1996 relating to the 1995
consolidated financial statements of Metromedia Fiber Network, Inc. (formerly
National Fiber Network, Inc.) included in Amendment No. 1 to the Registration
Statement (Form S-4) and related Prospectus for the registration of its 10%
Series B Senior Notes due 2008. Our report contains an explanatory paragraph
regarding an uncertainty as to the Company's ability to continue as a going
concern.
    
 
                                          /s/ M. R. Weiser & Co. LLP
                                          M.R. Weiser & Co. LLP
 
   
New York, New York
February 10, 1999
    

<PAGE>
                                                                    Exhibit 99.1


                              EXCHANGE AGENCY AGREEMENT


          This Agreement is entered into as of _____________, 1999 between IBJ
Whitehall Bank & Trust Company, a banking corporation organized under the laws
of the State of New York, as Exchange Agent (the "Agent") and Metromedia Fiber
Network, Inc. a corporation organized under the laws of the State of Delaware
(the "Company").

          The Company proposes to exchange (the "Exchange Offer") $650,000,000
aggregate principal amount of its 10% Series B Senior Notes due 2008 (the
"Exchange Notes"), in exchange for an equal aggregate principal amount of its
outstanding 10% Series A Senior Notes due 2008, (the "Initial Notes") pursuant
to the Registration Rights Agreement dated as of November 25, 1998.  The terms
and conditions of the Exchange Offer as currently contemplated are set forth in
a prospectus dated ______, 1999 (the "Prospectus"), proposed to be distributed
to all record holders of the Initial Notes.  The Initial Notes and the Exchange
Notes are collectively referred to herein as the "Securities."

          The Exchange Offer will terminate at 5:00 p.m. New York City Time on
_____________, 1999, unless extended by the Company in its sole discretion (the
"Expiration Date").  The Exchange Notes are to be issued by the Company pursuant
to the terms of an Indenture dated as of November 25, 1998 (the "Indenture")
between the Company and IBJ Whitehall Bank & Trust Company, as trustee (the
"Trustee"). 

          Subject to the provisions hereof, the Company hereby appoints and the
Agent hereby accepts the appointment as Agent for the purposes of receiving,
accepting for delivery and otherwise acting upon tenders of the Initial Notes
(the "Certificates") in accordance with the form of Letter of Transmittal
attached to the Prospectus (the "L/T") and with the terms and conditions set
forth herein and under the caption "The Exchange Offer" in the Prospectus.

          The Company expressly reserves the right to extend, amend or terminate
the Exchange Offer, and not to accept for exchange any Initial Notes not
theretofore accepted for exchange, upon the occurrence of any of the conditions
specified in the Prospectus under the caption "The Exchange Offer---Terms of the
Exchange Offer ---Conditions."  The Company will give oral (confirmed in
writing) or written notice of any extension, amendment, termination or
nonacceptance to the Agent as promptly as practicable.

          The Agent has received the following documents in connection with its
appointment (the "Exchange Offer Documents"):

               (1)  L/T
               (2)  a form of Notice of Guaranteed Delivery


<PAGE>
                                                                               2


               (3)  the Prospectus
               (4)  Tax Guidelines
               (5)  A cover letter to Clients
               (6)  A cover letter to DTC Participants

          The Agent is authorized and hereby agrees as follows:

               (a)  to establish an account with respect to the Initial Notes at
the Depository Trust Company ("DTC") for purposes of the Exchange Offer within
two business days after the date of the Prospectus, and any financial
institution that is a participant in DTC's systems shall be able to make
book-entry delivery of Initial Securities by causing DTC to transfer such
Initial Securities into the Agent's account in accordance with DTC's procedure
for such transfer;

               (b)  that tenders of Initial Notes may be made only as set forth
in the L/T and in the section of the Prospectus captioned "The Exchange
Offer--Terms of the Exchange Offer" and Initial Notes shall be considered
properly tendered to the Agent only when tendered in accordance with the
procedures set forth herein and therein;

               (c)  to address, and deliver by hand or next day courier, a
complete set of the Exchange Offer Documents to each person who, prior to the
Expiration Date, is or becomes a registered holder of Initial Notes promptly
after such person becomes a registered holder of Initial Notes;

               (d)  to receive all tenders of Initial Notes made pursuant to the
Exchange Offer and stamp the L/T with the day, month and approximate time of
receipt;

               (e)  to examine each L/T and Initial Notes received or agent's
message (as defined in the Prospectus) and book-entry transfer, as the case may
be to determine whether: (i) the L/T and any such other documents are duly
executed and properly completed in accordance with instructions set forth
therein and book-entry confirmations are in due and proper form and contain the
information required to be set forth therein and (ii) the Initial Notes have
otherwise been properly tendered.  In each case where the L/T or any other
document has been improperly completed or executed or book-entry confirmations
are not in due and proper form and do not contain adequate information or any of
the certificates for Initial Notes are not in proper form for transfer or some
other irregularity in connection with the acceptance of the Exchange Offer
exists, you will endeavor to inform the presenters of the need for fulfillment
of all requirements and to take any other action as may be necessary or
advisable to cause such irregularity to be corrected.  The Agent shall be
entitled to rely on the electronic messages sent by DTC regarding ATOP delivery
of the Notes to the Agent's account at DTC from the DTC participants listed 
on the DTC position listing provided to the Agent;


<PAGE>
                                                                               3


               (f)  to take such actions necessary and appropriate to correct
any irregularity or deficiency associated with any tender not in proper order;

               (g)  to follow instructions given by the Chief Executive Officer,
the President, the Senior Vice President, any Executive Vice President, or any
Vice President of the Company or any other party designated by such an officer
in writing (the "Designated Officers"), with respect to the waiver of any
irregularities or deficiencies associated with any tender;

               (h)  to hold all valid tenders subject to further instructions
from any Designated Officer;

               (i)  to render a report via facsimile, in the form of Exhibit 
A attached hereto, on each business day during the Exchange Offer to Howard 
Finkelstein, President and Chief Operating Officer at Metromedia Fiber 
Network, Gerard Benedetto, Chief Financial Officer at Metromedia Fiber 
Network, Arnold Wadler, Executive Vice President, General Counsel and 
Secretary at Metromedia Fiber Network and Metromedia Company, Mitchell Stier, 
Assistant General Counsel at Metromedia Fiber Network and Metromedia Company, 
Silvia Kessel, Executive Vice President at Metromedia Fiber Network and 
President at Kluge & Company, with copies to Douglas Cifu, Valerie Demont and 
Tanya Rolle at Paul, Weiss, Rifkind, Wharton & Garrison as listed on Exhibit 
C;

               (j)  to follow and act upon any written amendments, modifications
or supplements to these instructions, any of which may be given to the Agent by
any Designated Officer of the Company or such other person or persons as they
shall designate in writing;

               (k)  to return to the presentors, in accordance with the
provisions of the L/T, any Initial Notes that were not received in proper order
and as to which the irregularities or deficiencies were not cured or waived;

               (l)  in the event the Exchange Offer is consummated, to deliver
authenticated Exchange Notes to tendering Noteholders, in accordance with the
instructions of such Noteholders specified in the respective L/T's, as soon as
practicable after consummation thereof;

               (m)  to determine that all endorsements, guarantees, signatures,
authorities, stock transfer taxes (if any) and such other requirements are
fulfilled in connection with any request for issuance of the Exchange Notes in a
name other than that of the registered owner of the Initial Notes;

<PAGE>
                                                                               4


               (n)  to deliver to, or upon the order of, the Company all Initial
Notes received under the Exchange Offer, together with any related assignment
forms and other documents by first class mail, return receipt requested under a
blanket surety bond protecting the Agent and the Company from loss or liability
arising out of the non-receipt or non-delivery of such Initial Notes or
registered mail insured separately for the replacement value of each such
Initial Notes; and 

               (o)  subject to the other terms and conditions set forth in this
Agreement to take all other actions reasonable and necessary in the good faith
judgment of the Agent, to effect the foregoing matters.

          The Agent shall:

               (a)  have no duties or obligations other than those specifically
set forth herein or as may be subsequently agreed to in writing by you and the
Company;

               (b)  not be required to refer to any documents for the
performance of its obligations hereunder other than this Agreement, the
Prospectus, the L/T and the documents required to be submitted with the L/T;
other than such documents, the Agent will not be responsible or liable for any
terms, directions or information in the Prospectus or any other document or
agreement unless the Agent specifically agrees thereto in writing;

               (c)  not be required to act on the directions of any person,
including the persons named above, unless the Company provides a corporate
resolution to the Agent or other evidence satisfactory to the Agent of the
authority of such person;

               (d)  not be required to, and shall make no representations and
have no responsibilities as to, the validity, accuracy, value or genuineness of
(i) the Exchange Offer, (ii) any Certificates, L/Ts or documents prepared by the
Company in connection with the Exchange Offer or (iii) any signatures or
endorsements, other than its own;

               (e)  not be obligated to take any legal action hereunder that
might, in its judgment, involve any expense or liability, unless it has been
furnished with reasonable indemnity by the Company;

               (f)  be able to rely on and shall be protected in acting on the
written or oral instructions with respect to any matter relating to its actions
as Agent specifically covered by this Agreement, of any Designated Officer of
the Company;

               (g)  be able to rely on and shall be protected in acting upon any
certificate, instrument, opinion, notice, letter, telegram or any other document
or

<PAGE>
                                                                               5


security delivered to it and believed by it reasonably and in good faith to be
genuine and to have been signed by the proper party or parties;

               (h)  not be responsible for, or liable in any respect on account
of, the identity, authority or rights of any person executing or delivering or
purporting to execute or deliver any document or property under this Agreement
and shall have no responsibility with respect to the use or application of any
property delivered by it pursuant to the provisions hereof;

               (i)  be able to consult with counsel satisfactory to it
(including counsel for the Company or staff counsel of the Agent), and the
advice or opinion of such counsel shall be full and complete authorization and
protection in respect of any action taken, suffered or omitted by it hereunder
in good faith and in accordance with advice or opinion of such counsel;

               (j)  not be called on at any time to advise, and shall not
advise, any person delivering an L/T pursuant to the Exchange Offer as to the
value of the consideration to be received;

               (k)  not be liable for anything which it may do or refrain from
doing in connection with this Agreement except for its own gross negligence,
willful misconduct or bad faith;

               (l)  not be bound by any notice or demand, or any waiver or
modification of this Agreement or any of the terms hereof, unless evidenced by a
writing delivered to the Agent signed by the proper authority or authorities
and, if the Agent's duties or rights are affected, unless the Agent shall give
its prior written consent thereto;

               (m)  have no duty to enforce any obligation of any person to make
delivery, or to direct or cause any delivery to be made, or to enforce any
obligation of any person to perform any other act; 

               (n)  have the right to assume, in the absence of written notice
to the contrary from the proper person or persons, that a fact or an event by
reason of which an action would or might be taken by the Agent does not exist or
has not occurred without incurring liability for any action taken or omitted, or
any action suffered by the Agent to be taken or omitted, in good faith or in the
exercise of the Agent's best judgment, in reliance upon such assumption; and

               (o)  not be authorized to pay or offer to pay any concessions,
commissions or solicitation fees to any broker, dealer, bank or other persons or
to engage or utilize any person to solicit tenders.

<PAGE>
                                                                               6


          (p)  waive any lien, encumbrance or right of set-off whatsoever 
that the Agent may have with respect to funds deposited with the Agent for 
the payment of transfer taxes by reason of amounts, if any, borrowed by the 
Company, or any of its subsidiaries or affiliates pursuant to any loan or 
credit agreement with the Agent or for compensation owed to the Agent 
hereunder.

          (q)  arrange to comply with all requirements under the tax laws of 
the United States, including those relating to missing Tax Identification 
Numbers, and file any appropriate reports with the Internal Revenue Service.  
The Company understands that the Agent is required to deduct 31% on payments 
to holders who have not supplied their correct Taxpayer Identification Number 
or required certification.  Such funds will be turned over to the Internal 
Revenue Service in accordance with applicable regulations.

          The Agent shall be entitled to compensation as set forth in Exhibit B
attached hereto.

          The Company covenants and agrees to reimburse the Agent for, indemnify
it against, and hold it harmless from any and all reasonable costs and expenses
(including reasonable fees and expenses of one firm of counsel and allocated
cost of staff counsel) that may be paid or incurred or suffered by it or to
which it may become subject without gross negligence, willful misconduct or bad
faith on its part by reason of or as a result of its compliance with the
instructions set forth herein or with any additional or supplemental written or
oral instructions delivered to it pursuant hereto, or which may arise out of or
in connection with the administration and performance of its duties under this
Agreement.  The Company agrees to promptly notify the Agent of any extension of
the Expiration Date.

          This Agreement shall be construed and enforced in accordance with the
laws of the State of New York and shall inure to the benefit of, and the
obligations created hereby shall be binding upon, the successors and assigns of
the parties hereto.  The parties agree to submit to the exclusive jurisdiction 
of the federal or state courts located in the State of New York, New York 
County.

          Unless otherwise expressly provided herein, all notices, requests,
demands and other communications hereunder shall be in writing, shall be
delivered by hand, facsimile or by First Class Mail, postage prepaid, shall be
deemed given when received and shall be addressed to the Agent and the Company
at the respective addresses listed below or to such other addresses as they
shall designate from time to time in writing, forwarded in like manner.

               If to the Agent, to:

                    IBJ Whitehall Bank & Trust Company
                    One State Street

<PAGE>
                                                                               7


                    New York, NY 10004
                    Attention: Reorganization Operations Dept.
                    Telephone: (212) 858-2103
                    Facsimile:  (212) 858-2611

               with copies to:

                    IBJ Whitehall Bank & Trust Company 
                    One State Street
                    New York, New York 10004
                    Attn: Corporate Finance Trust Services
                    Telephone: (212) 858-2529
                    Facsimile:  (212) 858-2952

               If to the Company, to:

                    Metromedia Fiber Network, Inc.
                    c/o Metromedia Company
                    One Meadowlands Plaza
                    East Rutherford, NJ  07073-2173
                    Attention:  General Counsel
                    Telephone: (201) 531-8000
                    Facsimile:  (201) 531-2803

               with copies to:

                    Paul, Weiss, Rifkind, Wharton & Garrison
                    1285 Avenue of the Americas
                    New York, NY  10019-6064
                    Facsimile:  (212) 757-3990
                    Attention:  Douglas A. Cifu, Esq.
                               James M. Dubin, Esq.    

          Unless terminated earlier by the parties hereto, this Agreement 
shall terminate 90 days following the Expiration Date.  Notwithstanding the 
foregoing, the indemnification and compensation provisions of this Agreement 
shall survive the termination of this Agreement.  Upon any termination of 
this Agreement, the Agent shall promptly deliver to the Company any 
certificates for Securities, funds or property then held by you as Exchange 
Agent under this Agreement.

          This Agreement shall be binding and effective as of the date hereof.

<PAGE>
                                                                               8


          IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be executed on their behalf by their officers thereunto duly authorized, all as
of the day and year first above written.

                              IBJ Whitehall Bank & Trust Company


                              By:
                                 -------------------------------



                              Metromedia Fiber Network, Inc.


                              By:
                                 -------------------------------








<PAGE>

                                                                       EXHIBIT A
                                    SAMPLE REPORT

Date:______________________________
Report Number:_____________________
As of Date: _______________________

Ladies & Gentlemen:

          As Exchange Agent for the Exchange Offer dated ___________, 1999, we
hereby render the  following report:


Principal Amount previously received:
                                                                   -------------

Principal Amount received today:
                                                                   -------------

Principal Amount received against Guaranteed Deliveries:
                                                                   -------------

Principal Amount withdrawn today:
                                                                   -------------

TOTAL PRINCIPAL AMOUNT RECEIVED TO DATE:
                                                                   =============



                                        Very truly yours,



                                        Reorganization Operations Dept.

<PAGE>

                                                                       EXHIBIT B

                                     COMPENSATION


          The Agent for serving as the Exchange Agent pursuant to this
Agreement, shall receive a fee of $2,500, payable upon commencement of the
Exchange Offer, and the Agent's out-of-pocket expenses incurred in connection
with completing its duties pursuant to this Agreement.





<PAGE>
                                                                       EXHIBIT C


METROMEDIA FIBER NETWORK
One North Lexington Avenue
White Plains, NY 10601
Tel: (914) 421-6700

- ------------------------------------    --------------------------------------
             NAME                              BUSINESS TELEPHONE NUMBER
- ------------------------------------    --------------------------------------

Howard Finkelstein                      Tel: (914) 421-6702
PRESIDENT & CHIEF OPERATING OFFICER     Fax: (914) 421-6777

- ------------------------------------    --------------------------------------

Gerard Benedetto                        Tel: (914) 421-6705
CHIEF FINANCIAL OFFICER                 Fax: (914) 421-6777

- ------------------------------------    --------------------------------------


METROMEDIA COMPANY
One Meadowlands Plaza
East Rutherford, NJ 07073
Tel: (201) 531-8000

- ------------------------------------    --------------------------------------
             NAME                              BUSINESS TELEPHONE NUMBER
- ------------------------------------    --------------------------------------

Arnold L. Wadler                        Tel: (201) 531-8050
EVP, GENERAL COUNSEL & SECRETARY        Fax: (201) 531-2803

- ------------------------------------    --------------------------------------

Mitchell Stier                          Tel: (201) 531-8017
ASSISTANT GENERAL COUNSEL               Fax: (201) 531-2803

- ------------------------------------    --------------------------------------



<PAGE>


KLUGE & COMPANY
215 East 67th Street
New York, NY 10021
Tel: (212) 696-4387


- ------------------------------------    --------------------------------------
             NAME                              BUSINESS TELEPHONE NUMBER
- ------------------------------------    --------------------------------------

Silvia Kessel                           Tel: (212) 606-4387
PRESIDENT                               Fax: (212) 606-4337

- ------------------------------------    --------------------------------------



PAUL, WEISS, RIFKIND, WHARTON AND GARRISON
1285 Avenue of the Americas
24th Floor
New York, NY 10019
Tel: (212) 373-3000

- ------------------------------------    --------------------------------------
             NAME                              BUSINESS TELEPHONE NUMBER
- ------------------------------------    --------------------------------------

Douglas A. Cifu                         Tel: (212) 373-3436
PARTNER                                 Fax: (212) 373-2274

- ------------------------------------    --------------------------------------

Valerie M. Demont                       Tel: (212) 373-3076
ASSOCIATE                               Fax: (212) 373-2315

- ------------------------------------    --------------------------------------

Tanya L. Rolle                          Tel: (212) 373-3384
ASSOCIATE                               Fax: (212) 373-2004

- ------------------------------------    --------------------------------------




<PAGE>
                             LETTER OF TRANSMITTAL
 
                         METROMEDIA FIBER NETWORK, INC.
 
                     OFFER TO EXCHANGE $650,000,000 OF ITS
                       10% SERIES B SENIOR NOTES DUE 2008
                             (THE "EXCHANGE NOTES")
    WHICH HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
                      FOR $650,000,000 OF ITS OUTSTANDING
                       10% SERIES A SENIOR NOTES DUE 2008
                             (THE "INITIAL NOTES")
             PURSUANT TO THE PROSPECTUS, DATED              , 1999
- --------------------------------------------------------------------------------
    THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON
              , 1999 OR SUCH LATER DATE AND TIME TO WHICH THE EXCHANGE OFFER
   MAY BE EXTENDED (THE "EXPIRATION DATE").
- --------------------------------------------------------------------------------
 
                  THE EXCHANGE AGENT FOR THE EXCHANGE OFFER IS
                       IBJ WHITEHALL BANK & TRUST COMPANY
 
                        BY REGISTERED OR CERTIFIED MAIL:
                       IBJ Whitehall Bank & Trust Company
                                  P.O. Box 84
                             Bowling Green Station
                             New York, NY 10274-004
 
                         BY HAND OR OVERNIGHT DELIVERY:
                       IBJ Whitehall Bank & Trust Company
                                One State Street
                               New York, NY 10004
 
                    BY FACSIMILE FOR ELIGIBLE INSTITUTIONS:
                                 (212) 858-2952
                              Via Telex No: 177754
 
                   FOR CONFIRMATION AND/OR INFORMATION CALL:
                                 (212) 858-2176
 
DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET FORTH
ABOVE OR TRANSMISSION OF INSTRUCTIONS VIA FACSIMILE OTHER THAN AS SET FORTH
ABOVE DOES NOT CONSTITUTE A VALID DELIVERY.
 
                 PLEASE READ THIS ENTIRE LETTER OF TRANSMITTAL
                   CAREFULLY BEFORE COMPLETING ANY BOX BELOW
                           --------------------------
 
    List below the Initial Notes to which this Letter of Transmittal relates. If
the space provided below is inadequate, the certificate numbers and principal
amount of Initial Notes should be listed on a separate signed schedule affixed
hereto.
 
<TABLE>
<CAPTION>
- ---------------------------------------------------------------------------------------------------------------
          DESCRIPTION OF INITIAL NOTES                    (1)                  (2)                  (3)
- ---------------------------------------------------------------------------------------------------------------
                                                                                             PRINCIPAL AMOUNT
                                                                                             OF INITIAL NOTES
                                                                            PRINCIPAL            TENDERED
NAME(S) AND ADDRESS(ES) OF REGISTERED HOLDER(S)       CERTIFICATE           AMOUNT OF          (IF LESS THAN
           (PLEASE FILL IN, IF BLANK)                 NUMBER(S)*          INITIAL NOTES           ALL)**
<S>                                               <C>                  <C>                  <C>
- ---------------------------------------------------------------------------------------------------------------
                                                  -------------------------------------------------------------
                                                  -------------------------------------------------------------
                                                  -------------------------------------------------------------
- ---------------------------------------------------------------------------------------------------------------
</TABLE>
 
   *  Need not be completed by book-entry holders.
  **  Unless otherwise indicated, the holder will be deemed to have tendered the
      full aggregate principal amount represented by such Initial Notes.
- --------------------------------------------------------------------------------
<PAGE>
    The undersigned acknowledges that he or she has received and reviewed the
Prospectus, dated             , 1999 (the "Prospectus"), of Metromedia Fiber
Network, Inc., a Delaware corporation (the "Company"), and this Letter of
Transmittal (the "Letter"), which together constitute the Company's offer (the
"Exchange Offer") to exchange up to $650,000,000 aggregate principal amount of
its 10% Series B Senior Notes due 2008 (the "Exchange Notes") for a like
principal amount of the Company's issued and outstanding 10% Series A Senior
Notes due 2008 (collectively, the "Initial Notes").
 
    The undersigned has completed the appropriate boxes above and below and
signed this Letter to indicate the action the undersigned desires to take with
respect to the Exchange Offer.
 
    This Letter is to be used either if certificates of Initial Notes are to be
forwarded herewith or if delivery of Initial Notes is to be made by book-entry
transfer to an account maintained by the Exchange Agent at The Depository Trust
Company, pursuant to the procedures set forth in "The Exchange Offer--Terms of
the Exchange Offer--Procedures for Tendering" in the Prospectus. Delivery of
this Letter and any other required documents should be made to the Exchange
Agent. Delivery of documents to a book-entry transfer facility does not
constitute delivery to the Exchange Agent.
 
    Holders whose Initial Notes are not immediately available or who cannot
deliver their Initial Notes and all other documents required hereby to the
Exchange Agent on or prior to the Expiration Date must tender their Initial
Notes according to the guaranteed delivery procedure set forth in the Prospectus
under the caption "The Exchange Offer--Terms of the Exchange Offer--Procedures
for Tendering." See Instruction 1.
 
/ /  CHECK HERE IF INITIAL NOTES ARE BEING DELIVERED BY BOOK-ENTRY TRANSFER MADE
     TO AN ACCOUNT MAINTAINED BY THE EXCHANGE AGENT WITH THE BOOK-ENTRY TRANSFER
     FACILITY AND COMPLETE THE FOLLOWING:
 
Name of Tendering Institution
- --------------------------------------------------------------------------------
/ / The Depository Trust Company
 
Account Number
- --------------------------------------------------------------------------------
 
Transaction Code Number
- --------------------------------------------------------------------------------
 
/ /  CHECK HERE IF INITIAL NOTES ARE BEING DELIVERED PURSUANT TO A NOTICE OF
     GUARANTEED DELIVERY AND COMPLETE THE FOLLOWING:
 
Name of Registered Holder(s)
- --------------------------------------------------------------------------------
 
Name of Eligible Institution that Guaranteed Delivery
- --------------------------------------------------------------------------------
 
If delivered by book-entry transfer:
 
Account Number
- --------------------------------------------------------------------------------
 
Date of execution of Notice of Guaranteed Delivery
- --------------------------------------------------------------------------------
 
/ /  CHECK HERE IF YOU ARE A BROKER-DEALER AND WISH TO RECEIVE 10 ADDITIONAL
     COPIES OF THE PROSPECTUS AND 10 COPIES OF ANY AMENDMENTS OR SUPPLEMENTS
     THERETO.
 
                                       2
<PAGE>
Name:
- --------------------------------------------------------------------------------
 
Address:
- --------------------------------------------------------------------------------
 
    If the undersigned is not a broker-dealer, the undersigned represents that
it is acquiring the Exchange Notes in the ordinary course of business of the
undersigned, that it is not engaged in, and does not intend to engage in, or has
no arrangement or understanding with any person to participate in, a
distribution of Exchange Notes and that it is not an "affiliate" of the Company
within the meaning of Rule 405 under the Securities Act of 1933, as amended (the
"Securities Act"). If the undersigned is a broker-dealer that will receive
Exchange Notes for its own account in exchange for Initial Notes that were
acquired as a result of market-making activities or other trading activities, it
may be deemed to be an "underwriter" within the meaning of the Securities Act
and must acknowledge that it will deliver a prospectus meeting the requirements
of the Securities Act in connection with any resale of such Exchange Notes;
however, by so acknowledging and by delivering a prospectus, the undersigned
will not be deemed to admit that it is an "underwriter" within the meaning of
the Securities Act.
 
                                       3
<PAGE>
              PLEASE READ THE ACCOMPANYING INSTRUCTIONS CAREFULLY
 
Ladies and Gentlemen:
 
    Upon the terms and subject to the conditions of the Exchange Offer, the
undersigned hereby tenders to the Company the aggregate principal amount of
Initial Notes indicated above. Subject to, and effective upon, the acceptance
for exchange of the Initial Notes tendered hereby, the undersigned hereby sells,
assigns and transfers to, or upon the order of, the Company all right, title and
interest in and to such Initial Notes as are being tendered hereby.
 
    The undersigned hereby represents and warrants that the undersigned has full
power and authority to tender, sell, assign and transfer the Initial Notes
tendered hereby and that the Company will acquire good and unencumbered title
thereto, free and clear of all liens, restrictions, charges and encumbrances and
not subject to any adverse claim when the same are accepted by the Company. The
undersigned will, upon request, execute and deliver any additional documents
deemed by the Company or the Exchange Agent to be necessary or desirable to
complete the sale, assignment and transfer of the Initial Notes tendered hereby.
 
    The undersigned also acknowledges that this Exchange Offer is being made in
reliance on the Company's belief, based on interpretations by the staff of the
Securities and Exchange Commission (the "SEC") to third parties in unrelated
transactions, that the Exchange Notes issued in exchange for the Initial Notes
pursuant to the Exchange Offer may be offered for resale, resold and otherwise
transferred by holders thereof (other than (i) any such holder that is an
"affiliate" of the Company within the meaning of Rule 405 under the Securities
Act or (ii) any broker-dealer that purchases Notes from the Company to resell
pursuant to Rule 144A under the Securities Act ("Rule 144A") or any other
available exemption) without compliance with the registration and prospectus
delivery provisions of the Securities Act, provided that such Exchange Notes are
acquired in the ordinary course of such holders' business and such holders have
no arrangement or understanding with any person to participate in the
distribution of such Exchange Notes and are not participating in, and do not
intend to participate in, the distribution of such Exchange Notes. The
undersigned acknowledges that any holder of Initial Notes using the Exchange
Offer to participate in a distribution of the Exchange Notes (i) cannot rely on
the position of the staff of the SEC enunciated in its interpretive letter with
respect to Exxon Capital Holdings Corporation (available April 13, 1989) or
similar letters and (ii) must comply with the registration and prospectus
requirements of the Securities Act in connection with a secondary resale
transaction.
 
    The undersigned represents that (i) the Exchange Notes acquired pursuant to
the Exchange Offer are being obtained in the ordinary course of business of the
person receiving such Exchange Notes, whether or not such person is the holder,
(ii) such holder or such other person has no arrangement or understanding with
any person to participate in the distribution of such Exchange Notes within the
meaning of the Securities Act and is not participating in, and does not intend
to participate in, the distribution of such Exchange Notes within the meaning of
the Securities Act, and (iii) such holder or such other person is not an
"affiliate," as defined in Rule 405 under the Securities Act, of the Company or,
if such holder or such other person is an affiliate, such holder or such other
person will comply with the registration and prospectus delivery requirements of
the Securities Act to the extent applicable.
 
    If the undersigned is not a broker-dealer, the undersigned represents that
it is not engaged in, and does not intend to engage in, a distribution of
Exchange Notes. If the undersigned is a broker-dealer that will receive Exchange
Notes for its own account in exchange for Initial Notes that were acquired as a
result of market-making activities or other trading activities, it may be deemed
to be an "underwriter" within the meaning of the Securities Act and acknowledges
that it will deliver a prospectus meeting the requirements of the Securities Act
in connection with any resale, offer to resell or other transfer of such
Exchange Notes; however, by so acknowledging and by delivering a prospectus, the
undersigned will not be deemed to admit that it is an "underwriter" within the
meaning of the Securities Act.
 
                                       4
<PAGE>
    The undersigned, if a California resident, hereby further represents and
warrants that the undersigned (or the beneficial owner of the Initial Notes
tendered hereby, if not the undersigned) (i) is a bank, savings and loan
association, trust company, insurance company, investment company registered
under the Investment Company Act of 1940, pension or profit-sharing trust (other
than a pension or profit-sharing trust of the Company, a self-employed
individual retirement plan, or individual retirement account), or a corporation
which has a net worth on a consolidated basis according to its most recent
audited financial statement of not less than $14,000,000, and (ii) is acquiring
the Exchange Notes for its own account for investment purposes (or for the
account of the beneficial owner of such Exchange Notes for investment purposes).
 
    All authority conferred or agreed to be conferred in this Letter and every
obligation of the undersigned hereunder shall be binding upon the successors,
assigns, heirs, executors, administrators, trustees in bankruptcy and legal
representatives of the undersigned and shall not be affected by, and shall
survive, the death or incapacity of the undersigned. This tender may be
withdrawn only in accordance with the procedures set forth in the instructions
contained in this Letter.
 
    The undersigned understands that tenders of the Initial Notes pursuant to
any one of the procedures described under "The Exchange Offer--Terms of the
Exchange Offer--Procedures for Tendering" in the Prospectus and in the
instructions hereto will constitute a binding agreement between the undersigned
and the Company in accordance with the terms and subject to the conditions of
the Exchange Offer.
 
    The undersigned recognizes that, under certain circumstances set forth in
the Prospectus under "The Exchange Offer--Terms of the Exchange
Offer--Conditions," the Company may not be required to accept for exchange any
of the Initial Notes tendered. Initial Notes not accepted for exchange or
withdrawn will be returned to the undersigned at the address set forth below
unless otherwise indicated under "Special Delivery Instructions" below.
 
    Unless otherwise indicated herein in the box entitled "Special Issuance
Instructions" below, please issue the Exchange Notes (and, if applicable,
substitute certificates representing Initial Notes for any Initial Notes not
exchanged) in the name of the undersigned. Similarly, unless otherwise indicated
under the box entitled "Special Delivery Instructions" below, please deliver the
Exchange Notes (and, if applicable, substitute certificates representing Initial
Notes for any Initial Notes not exchanged) to the undersigned at the address
shown above in the box entitled "Description of Initial Notes."
 
    THE BOOK-ENTRY TRANSFER FACILITY, AS THE HOLDER OF RECORD OF CERTAIN INITIAL
NOTES, HAS GRANTED AUTHORITY TO BOOK-ENTRY TRANSFER FACILITY PARTICIPANTS WHOSE
NAMES APPEAR ON A SECURITY POSITION LISTING WITH RESPECT TO SUCH INITIAL NOTES
AS OF THE DATE OF TENDER OF SUCH INITIAL NOTES TO EXECUTE AND DELIVER THE LETTER
OF TRANSMITTAL AS IF THEY WERE THE HOLDERS OF RECORD. ACCORDINGLY, FOR PURPOSES
OF THIS LETTER OF TRANSMITTAL, THE TERM "HOLDER" SHALL BE DEEMED TO INCLUDE SUCH
BOOK-ENTRY TRANSFER FACILITY PARTICIPANTS.
 
    THE UNDERSIGNED, BY COMPLETING THE BOX ENTITLED "DESCRIPTION OF INITIAL
NOTES" ABOVE AND SIGNING THIS LETTER AND DELIVERING SUCH NOTES AND THIS LETTER
TO THE EXCHANGE AGENT, WILL BE DEEMED TO HAVE TENDERED THE INITIAL NOTES AS SET
FORTH IN SUCH BOX ABOVE.
 
                                       5
<PAGE>
- --------------------------------------------------------------------------------
 
                                PLEASE SIGN HERE
                   (TO BE COMPLETED BY ALL TENDERING HOLDERS)
                  (COMPLETE ACCOMPANYING SUBSTITUTE FORM W-9)
 
  Dated: .....................................................................
 
<TABLE>
<S>                                           <C>
  X ......................................    ............................................
 
  X ......................................    ............................................
   SIGNATURE(S) OF OWNER(S)/OR AUTHORIZED
   SIGNATORY                                  DATE
</TABLE>
 
  Area Code and Telephone Number .............................................
 
      If a holder is tendering any Initial Notes, this Letter must be signed
  by the registered holder(s) as the name(s) appear(s) on the certificate(s)
  for the Initial Notes or by any person(s) authorized to become registered
  holder(s) by endorsements and documents transmitted herewith. If signature
  is by a trustee, executor, administrator, guardian, officer or other person
  acting in a fiduciary or representative capacity, please set forth full
  title. See Instruction 3.
 
<TABLE>
<S>            <C>
  Names        ...............................................................................
 
               ...............................................................................
                                           (PLEASE TYPE OR PRINT)
 
  Capacity:    ...............................................................................
 
               ...............................................................................
 
  Address      ...............................................................................
 
               ...............................................................................
                                             (INCLUDE ZIP CODE)
</TABLE>
 
                              SIGNATURE GUARANTEE
                         (IF REQUIRED BY INSTRUCTION 3)
 
  Signature(s) Guaranteed by
  an Eligible Institution: ...................................................
                             (AUTHORIZED SIGNATURE)
 
  ...........................................................................
                                    (TITLE)
 
  ...........................................................................
                                 (NAME OF FIRM)
 
  Dated: .....................................................................
 
  ----------------------------------------------------------------------------
 
                                       6
<PAGE>
- -------------------------------------------
                         SPECIAL ISSUANCE INSTRUCTIONS
                           (SEE INSTRUCTIONS 3 AND 4)
 
      To be completed ONLY if certificates for Exchange Notes are to be issued
  in the name of and sent to someone other than the person or persons whose
  signature(s) appear on this Letter above.
 
  ISSUE: EXCHANGE NOTES TO:
 
  NAME(S): ...................................................................
                             (PLEASE TYPE OR PRINT)
 
   ..........................................................................
                             (PLEASE TYPE OR PRINT)
 
  ADDRESS: ...................................................................
 
   ...........................................................................
 
   ...........................................................................
                                                                   (ZIP CODE)
 
  SOCIAL SECURITY NUMBER: ....................................................
 
                         (COMPLETE SUBSTITUTE FORM W-9)
 
- ------------------------------------------------------
- ------------------------------------------------------
 
                         SPECIAL DELIVERY INSTRUCTIONS
                           (SEE INSTRUCTIONS 3 AND 4)
 
      To be completed ONLY if certificates for Exchange Notes are to be sent
  to someone other than the person or persons whose signature(s) appear(s) on
  this Letter above or to such person or persons at an address other than
  shown in the box entitled "Description of Initial Notes" on this Letter
  above.
 
  MAIL: EXCHANGE NOTES TO:
 
  NAME(S): ...................................................................
                             (PLEASE TYPE OR PRINT)
 
   ..........................................................................
                             (PLEASE TYPE OR PRINT)
 
  ADDRESS: ...................................................................
 
   ...........................................................................
 
   ...........................................................................
                                                                   (ZIP CODE)
- -----------------------------------------------------
 
    IMPORTANT: UNLESS GUARANTEED DELIVERY PROCEDURES ARE COMPLIED WITH, THIS
LETTER OR A FACSIMILE HEREOF OR AN AGENT'S MESSAGE (IN EACH CASE, TOGETHER WITH
THE CERTIFICATE(S) FOR INITIAL NOTES OR A CONFIRMATION OF BOOK-ENTRY TRANSFER OF
SUCH INITIAL NOTES AND ALL OTHER REQUIRED DOCUMENTS) MUST BE RECEIVED BY THE
EXCHANGE AGENT PRIOR TO THE EXPIRATION DATE.
 
                                       7
<PAGE>
                                  INSTRUCTIONS
 
         FORMING PART OF THE TERMS AND CONDITIONS OF THE EXCHANGE OFFER
 
1.  DELIVERY OF THIS LETTER AND INITIAL NOTES; GUARANTEED DELIVERY PROCEDURE.
 
    This Letter is to be used to forward, and must accompany, all certificates
representing Initial Notes tendered pursuant to the Exchange Offer unless such
certificates are accompanied by an Agent's Message (as defined in the
Prospectus) in which case you need not submit this Letter to the Exchange Agent.
Certificates representing the Initial Notes in proper form for transfer (or a
confirmation of book-entry transfer of such Initial Notes into the Exchange
Agent's account at the book-entry transfer facility) must be received by the
Exchange Agent at its address set forth herein on or before the Expiration Date.
A tender will not be deemed to have been timely received when the tendering
holder's properly completed and duly signed Letter or an Agent's Message
accompanied by the Initial Notes is mailed prior to the Expiration Date but is
received by the Exchange Agent after the Expiration Date.
 
    THE METHOD OF DELIVERY OF THIS LETTER, THE INITIAL NOTES AND ALL OTHER
REQUIRED DOCUMENTS IS AT THE ELECTION AND RISK OF THE TENDERING HOLDERS, BUT THE
DELIVERY WILL BE DEEMED MADE ONLY WHEN ACTUALLY RECEIVED OR CONFIRMED BY THE
EXCHANGE AGENT. IF SUCH DELIVERY IS BY MAIL, IT IS RECOMMENDED THAT REGISTERED
MAIL PROPERLY INSURED, WITH RETURN RECEIPT REQUESTED, BE USED. IN ALL CASES,
SUFFICIENT TIME SHOULD BE ALLOWED TO PERMIT TIMELY DELIVERY.
 
    If a holder desires to tender Initial Notes and such holder's Initial Notes
are not immediately available or time will not permit such holder's Letter of
Transmittal, Initial Notes (or a confirmation of book-entry transfer of Initial
Notes into the Exchange Agent's account at the book-entry transfer facility with
an Agent's Message) or other required documents to reach the Exchange Agent on
or before the Expiration Date, such holder may still tender in the Exchange
Offer if:
 
        (a) the tender is made through an Eligible Institution (as defined
    below);
 
        (b) prior to the Expiration Date, the Exchange Agent receives from such
    Eligible Institution a properly completed and duly executed Letter of
    Transmittal (or facsimile thereof) and Notice of Guaranteed Delivery,
    substantially in the form provided by us (by facsimile transmission, mail or
    hand delivery), setting forth your name and address as holder of the Initial
    Notes and the amount of Initial Notes tendered, stating that the tender is
    being made thereby and guaranteeing that within five business days after the
    Expiration Date the certificates for all physically tendered Initial Notes,
    in proper form for transfer, or a book-entry confirmation with an Agent's
    Message, as the case may be, and any other documents required by the Letter
    of Transmittal will be deposited by the Eligible Institution with the
    Exchange Agent; and
 
        (c) the certificates for all physically tendered Initial Notes, in
    proper form for transfer, or a book-entry confirmation as the case may be,
    and all other documents required by this Letter of Transmittal are received
    by the Exchange Agent within five business days after the Expiration Date.
 
    See "The Exchange Offer--Terms of the Exchange Offer--Procedures for
Tendering" in the Prospectus.
 
2.  WITHDRAWALS.
 
    Any holder who has tendered Initial Notes may withdraw the tender by
delivering written notice of withdrawal (which may be sent by telegram,
facsimile (receipt confirmed by telephone and an original delivered by
guaranteed overnight courier)) to the Exchange Agent prior to the close of
business on the Expiration Date and prior to acceptance for exchange thereof by
us. For a withdrawal to be effective, a written notice of withdrawal must (i)
specify the name of the person having tendered the Initial Notes to be withdrawn
(the "Depositor"), (ii) identify the Initial Notes to be withdrawn (including
the certificate number or numbers and principal amount of such Initial Notes),
(iii) signed by the holder in the same
 
                                       8
<PAGE>
manner as the original signature on the Letter by which such Initial Notes were
tendered or as otherwise set forth in Instruction 3 below (including any
required signature guarantees), or be accompanied by documents of transfer
sufficient to have the Trustee (as defined in the Prospectus) register the
transfer of such Initial Notes pursuant to the terms of the Indenture into the
name of the person withdrawing the tender and (iv) specify the name in which any
such Initial Notes are to be registered, if different from that of the
Depositor. If Initial Notes have been tendered pursuant to the procedure for
book-entry transfer, any notice of withdrawal must specify the name and number
of the participant's account at the book-entry transfer facility to be credited,
if different from that of the Depositor, with the withdrawn Initial Notes or
otherwise comply with the book-entry transfer facility's procedures. See "The
Exchange Offer--Terms of the Exchange Offer--Withdrawal of Tenders" in the
Prospectus.
 
3.  SIGNATURES ON THIS LETTER; BOND POWERS AND ENDORSEMENTS; GUARANTEE OF
    SIGNATURES.
 
    If this Letter is signed by the registered holder of the Initial Notes
tendered hereby, the signature must correspond with the name as written on the
face of the certificates without alteration, enlargement or any change
whatsoever.
 
    If this Letter is signed by a participant in DTC, the signature must
correspond with the name as it appears on the security position listing as the
holder of the Initial Notes.
 
    If this Letter or any Initial Notes or bond powers are signed by trustees,
executors, administrators, guardians, attorneys-in-fact, officers of
corporations or others acting in a fiduciary or representative capacity, such
persons should so indicate when signing. Unless waived by us, evidence
satisfactory to us of their authority to so act must also be submitted with the
Letter of Transmittal.
 
    If any tendered Initial Notes are owned of record by two or more joint
owners, all such owners must sign this Letter.
 
    The signatures on this Letter or a notice of withdrawal, as the case may be,
must be guaranteed by a member firm of a registered national securities exchange
or of the National Association of Securities Dealers, Inc., a commercial bank or
trust company having an office or correspondent in the United States or an
"eligible guarantor" institution within the meaning of Rule 17Ad-15 under the
Securities Exchange Act of 1934, as amended--(each, an "Eligible Institution"),
unless the Initial Notes are tendered: (i) by a registered holder (or by a
participant in DTC whose name appears on a security position listing as the
owner) who has not completed the box entitled "Special Issuance Instructions" or
"Special Delivery Instructions" on this Letter and the Exchange Notes are being
issued directly to such registered holder (or deposited into the participant's
account at DTC), or (ii) for the account of an Eligible Institution.
 
4.  SPECIAL ISSUANCE AND DELIVERY INSTRUCTIONS.
 
    Tendering holders of Initial Notes should indicate in the applicable box the
name and address to which Exchange Notes issued pursuant to the Exchange Offer
are to be issued or sent, if different from the name or address of the person
signing this Letter. In the case of issuance in a different name, the employer
identification or social security number of the person named must also be
indicated. If no such instructions are given, any Exchange Notes will be issued
in the name of, and delivered to, the name or address of the person signing this
Letter and any Initial Notes not accepted for exchange will be returned to the
name or address of the person signing this Letter.
 
5.  BACKUP FEDERAL INCOME TAX WITHHOLDING AND SUBSTITUTE FORM W-9.
 
    Under the federal income tax laws, payments that may be made by the Company
on account of Exchange Notes issued pursuant to the Exchange Offer may be
subject to backup withholding at the rate of 31%. In order to avoid such backup
withholding, each tendering holder should complete and sign the Substitute Form
W-9 included in this Letter and either (a) provide the correct taxpayer
identification
 
                                       9
<PAGE>
number ("TIN") and certify, under penalties of perjury, that the TIN provided is
correct and that (i) the holder has not been notified by the Internal Revenue
Service (the "IRS") that the holder is subject to backup withholding as a result
of failure to report all interest or dividends or (ii) the IRS has notified the
holder that the holder is no longer subject to backup withholding; or (b)
provide an adequate basis for exemption. If the tendering holder has not been
issued a TIN and has applied for one, or intends to apply for one in the near
future, such holder should write "Applied For" in the space provided for the TIN
in Part I of the Substitute Form W-9, sign and date the Substitute Form W-9, and
sign the Certificate of Payee Awaiting Taxpayer Identification Number. If
"Applied For" is written in Part I, the Company (or the Paying Agent under the
Indenture governing the Exchange Notes) shall retain 31% of payments made to the
tendering holder during the sixty (60) day period following the date of the
Substitute Form W-9. If the holder furnishes the Exchange Agent or the Company
with his or her TIN within sixty (60) days after the date of the Substitute Form
W-9, the Company (or the Paying Agent) shall remit such amounts retained during
the sixty (60) day period to the holder and no further amounts shall be retained
or withheld from payments made to the holder thereafter. If, however, the holder
has not provided the Exchange Agent or the Company with his or her TIN within
such sixty (60) day period, the Company (or the Paying Agent) shall remit such
previously retained amounts to the IRS as backup withholding. In general, if a
holder is an individual, the taxpayer identification number is the Social
Security number of such individual. If the Exchange Agent or the Company is not
provided with the correct taxpayer identification number, the holder may be
subject to a $50 penalty imposed by the IRS. Certain holders (including, among
others, all corporations and certain foreign individuals) are not subject to
these backup withholding and reporting requirements. In order for a foreign
individual to qualify as an exempt recipient, such holder must submit a
statement (generally, IRS Form W-8), signed under penalties of perjury,
attesting to that individual's exempt status. Such statements can be obtained
from the Exchange Agent. For further information concerning backup withholding
and instructions for completing the Substitute Form W-9 (including how to obtain
a taxpayer identification number if you do not have one and how to complete the
Substitute Form W-9 if Initial Notes are registered in more than one name),
consult the enclosed Guidelines for Certification of Taxpayer Identification
Number on Substitute Form W-9.
 
    Failure to complete the Substitute Form W-9 will not, by itself, cause
Initial Notes to be deemed invalidly tendered, but may require the Company (or
the Paying Agent) to withhold 31% of the amount of any payments made on account
of the Exchange Notes. Backup withholding is not an additional federal income
tax. Rather, the federal income tax liability of a person subject to backup
withholding will be reduced by the amount of tax withheld. If withholding
results in an overpayment of taxes, a refund may be obtained.
 
6.  TRANSFER TAXES.
 
    The Company will pay all transfer taxes, if any, applicable to the transfer
of Initial Notes to it or its order pursuant to the Exchange Offer. If, however,
Exchange Notes and/or substitute Initial Notes not exchanged or accepted for
exchange are to be delivered to, or are to be registered or issued in the name
of, any person other than the registered holder of the Initial Notes tendered
hereby, or if tendered Initial Notes are registered in the name of any person
other than the person signing this Letter, or if a transfer tax is imposed for
any reason other than the transfer of Initial Notes to the Company or its order
pursuant to the Exchange Offer, the amount of any such transfer taxes (whether
imposed on the registered holder or any other persons) will be payable by the
tendering holder. If satisfactory evidence of payment of such taxes or exemption
therefrom is not submitted herewith, the amount of such transfer taxes will be
billed directly to such tendering holder.
 
    Except as provided in this Instruction 6, it will not be necessary for
transfer tax stamps to be affixed to the Initial Notes specified in this Letter.
 
                                       10
<PAGE>
7.  WAIVER OF CONDITIONS.
 
    Conditions enumerated in the Prospectus may be waived by the Company, in
whole or in part, at any time from time to time in its reasonable discretion.
 
8.  NO CONDITIONAL TENDERS.
 
    No alternative, conditional, irregular or contingent tenders will be
accepted. All tendering holders of Initial Notes, by execution of this Letter,
shall waive any right to receive notice of the acceptance of their Initial Notes
for exchange.
 
    Neither the Company nor any other person is obligated to give notice of
defects or irregularities in any tender, nor shall any of them incur any
liability for failure to give any such notice.
 
9.  INADEQUATE SPACE.
 
    If the space provided herein is inadequate, the aggregate principal amount
of Initial Notes being tendered and the certificate number or numbers (if
available) should be listed on a separate schedule attached hereto and
separately signed by all parties required to sign this Letter.
 
10. MUTILATED, LOST, STOLEN OR DESTROYED INITIAL NOTES.
 
    If any certificate has been lost, mutilated, destroyed or stolen, the holder
should promptly notify IBJ Whitehall Bank & Trust Company at the telephone
number indicated above. The holder will then be instructed as to the steps that
must be taken to replace the certificate(s). This Letter of Transmittal and
related documents cannot be processed until the Initial Notes have been
replaced.
 
11. REQUESTS FOR ASSISTANCE OR ADDITIONAL COPIES.
 
    Questions relating to the procedure for tendering, as well as requests for
additional copies of the Prospectus and this Letter, may be directed to IBJ
Whitehall Bank & Trust Company at the address and telephone number indicated
above.
 
                                       11
<PAGE>
                    TO BE COMPLETED BY ALL TENDERING HOLDERS
                              (SEE INSTRUCTION 5)
                  PAYER'S NAME: METROMEDIA FIBER NETWORK, INC.
 
<TABLE>
<C>                               <S>                              <C>
- ---------------------------------------------------------------------------------------------------
           SUBSTITUTE             Part I--Taxpayer Identification
                                  Number
 
            FORM W-9              Enter your taxpayer                  ------------------------
   Department of the Treasury     identification number in the          Social Security Number
    Internal Revenue Service      appropriate box. For most                       OR
                                  individuals, this is your            ------------------------
                                  social security number. If you    Employer Identification Number
                                  do not have a number, see how
                                  to obtain a "TIN" in the
                                  enclosed Guidelines.
                                  NOTE: If the account is in more
                                  than one name, see the chart on
                                  page 2 of the enclosed
                                  Guidelines to determine what
                                  number to give.
 
                                  -----------------------------------------------------------------
 
                                  Part II--For Payees Exempt From Backup Withholding (see enclosed
                                  Guidelines)
 
                                  -----------------------------------------------------------------
      PAYER'S REQUEST FOR         CERTIFICATION--UNDER THE PENALTIES OF PERJURY, I CERTIFY THAT:
    TAXPAYER IDENTIFICATION
        NUMBER (TIN) AND
         CERTIFICATION
                                  (1) the number shown on this form is my correct Taxpayer
                                      Identification Number (or I am waiting for a number to be
                                      issued to me), and
                                  (2) I am not subject to backup withholding either because I have
                                      not been notified by the Internal Revenue Service (the "IRS")
                                      that I am subject to backup withholding as a result of a
                                      failure to report all interest or dividends or the IRS has
                                      notified me that I am no longer subject to backup
                                      withholding.
 
                                  -----------------------------------------------------------------
 
                                  Signature _________________________    Date _______________
- ---------------------------------------------------------------------------------------------------
 
 CERTIFICATION GUIDELINES--You must cross out item (2) of the above certification if you have been
 notified by the IRS that you are subject to backup withholding because of underreporting of
 interest or dividends on your tax return. However, if after being notified by the IRS that you
 were subject to backup withholding you received another notification from the IRS that you are no
 longer subject to backup withholding, do not cross out item (2).
- ---------------------------------------------------------------------------------------------------
</TABLE>
 
         CERTIFICATION OF PAYEE AWAITING TAXPAYER IDENTIFICATION NUMBER
 
    I CERTIFY, UNDER PENALTIES OF PERJURY, THAT A TAXPAYER IDENTIFICATION NUMBER
HAS NOT BEEN ISSUED TO ME, AND THAT I MAILED OR DELIVERED AN APPLICATION TO
RECEIVE A TAXPAYER IDENTIFICATION NUMBER TO THE APPROPRIATE INTERNAL REVENUE
SERVICE CENTER OR SOCIAL SECURITY ADMINISTRATION OFFICE (OR I INTEND TO MAIL OR
DELIVER AN APPLICATION IN THE NEAR FUTURE). I UNDERSTAND THAT IF I DO NOT
PROVIDE A TAXPAYER IDENTIFICATION NUMBER TO THE PAYER, 31 PERCENT OF ALL
PAYMENTS MADE TO ME ON ACCOUNT OF THE EXCHANGE NOTES SHALL BE RETAINED UNTIL I
PROVIDE A TAXPAYER IDENTIFICATION NUMBER TO THE PAYER AND THAT, IF I DO NOT
PROVIDE MY TAXPAYER IDENTIFICATION NUMBER WITHIN SIXTY (60) DAYS, SUCH RETAINED
AMOUNTS SHALL BE REMITTED TO THE INTERNAL REVENUE SERVICE AS BACKUP WITHHOLDING
AND 31 PERCENT OF ALL REPORTABLE PAYMENTS MADE TO ME THEREAFTER WILL BE WITHHELD
AND REMITTED TO THE INTERNAL REVENUE SERVICE UNTIL I PROVIDE A TAXPAYER
IDENTIFICATION NUMBER.
 
Signature _________________________                         Date _______________
 
NOTE: FAILURE TO COMPLETE AND RETURN THIS FORM MAY RESULT IN BACKUP WITHHOLDING
      OF 31% OF ANY PAYMENTS MADE TO YOU ON ACCOUNT OF THE EXCHANGE NOTES.
      PLEASE REVIEW THE ENCLOSED GUIDELINES FOR CERTIFICATION OF TAXPAYER
      IDENTIFICATION NUMBER ON SUBSTITUTE FORM W-9 FOR ADDITIONAL DETAILS.
 
                                       12

<PAGE>
                                                                    EXHIBIT 99.3
 
                         NOTICE OF GUARANTEED DELIVERY
                                      FOR
                             TENDER OF OUTSTANDING
                       10% SERIES A SENIOR NOTES DUE 2008
                                IN EXCHANGE FOR
                       10% SERIES B SENIOR NOTES DUE 2008
            REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
                                       OF
                         METROMEDIA FIBER NETWORK, INC.
 
    Registered holders of outstanding 10% Series A Senior Notes due 2008 (the
"Initial Notes") who wish to tender their Initial Notes in exchange for a like
principal amount of 10% Series B Senior Notes due 2008 (the "Exchange Notes")
and whose Initial Notes are not immediately available or who cannot deliver
their Initial Notes and Letter of Transmittal (and any other documents required
by the Letter of Transmittal) to IBJ Whitehall Bank & Trust Company (the
"Exchange Agent") prior to the Expiration Date, may use this Notice of
Guaranteed Delivery or one substantially equivalent hereto. This Notice of
Guaranteed Delivery may be delivered by hand or sent by facsimile transmission
(receipt confirmed by telephone and an original delivered by guaranteed
overnight courier) or letter to the Exchange Agent. See "The Exchange
Offer--Terms of the Exchange Offer--Procedures for Tendering" in the Prospectus.
 
                 The Exchange Agent for the Exchange Offer is:
                       IBJ WHITEHALL BANK & TRUST COMPANY
                        BY REGISTERED OR CERTIFIED MAIL:
                       IBJ Whitehall Bank & Trust Company
                                  P.O. Box 84
                             Bowling Green Station
                             New York, NY 10274-004
                   Attn: Reorganization Operations Department
                         BY HAND OR OVERNIGHT DELIVERY:
                       IBJ Whitehall Bank & Trust Company
                                One State Street
                               New York, NY 10004
           Attn: Securities Processing Window, Subcellar One, (SC-1)
                    BY FACSIMILE FOR ELIGIBLE INSTITUTIONS:
                                 (212) 858-2611
                              Via Telex No: 177754
                   FOR CONFIRMATION AND/OR INFORMATION CALL:
                                 (212) 858-2103
 
    Delivery of this Notice of Guaranteed Delivery to an address other than as
set forth above or transmission of instructions via a facsimile transmission to
a number other than as set forth above will not constitute a valid delivery.
 
    This Notice of Guaranteed Delivery is not to be used to guarantee
signatures. If a signature on a Letter of Transmittal is required to be
guaranteed by an Eligible Institution (as defined in the Prospectus), such
signature guarantee must appear in the applicable space provided on the Letter
of Transmittal for Guarantee of Signatures.
<PAGE>
Ladies and Gentlemen:
 
    The undersigned hereby tenders the principal amount of Initial Notes
indicated below, upon the terms and subject to the conditions contained in the
Prospectus dated            , 1999 of Metromedia Fiber Network, Inc. (the
"Prospectus"), receipt of which is hereby acknowledged.
 
                       DESCRIPTION OF SECURITIES TENDERED
 
<TABLE>
<CAPTION>
    NAME AND ADDRESS OF
  REGISTERED HOLDER AS IT
APPEARS ON THE 10% SERIES A
   SENIOR NOTES DUE 2008                                  AGGREGATE PRINCIPAL AMOUNT
     ("INITIAL NOTES")        CERTIFICATE NUMBER(S) OF          REPRESENTED BY         PRINCIPAL AMOUNT OF INITIAL
      (PLEASE PRINT)           INITIAL NOTES TENDERED            INITIAL NOTES               NOTES TENDERED
- ---------------------------  ---------------------------  ---------------------------  ---------------------------
<S>                          <C>                          <C>                          <C>
 
   ---------------------        ---------------------        ---------------------        ---------------------
 
   ---------------------        ---------------------        ---------------------        ---------------------
 
   ---------------------        ---------------------        ---------------------        ---------------------
 
   ---------------------        ---------------------        ---------------------        ---------------------
 
   ---------------------        ---------------------        ---------------------        ---------------------
</TABLE>
 
                   THE FOLLOWING GUARANTEE MUST BE COMPLETED
                             GUARANTEE OF DELIVERY
                    (NOT TO BE USED FOR SIGNATURE GUARANTEE)
 
    The undersigned, a firm that is a member of a registered national securities
exchange or a member of the National Association of Securities Dealers, Inc. or
a commercial bank or trust company having an office, branch, agency or
correspondent in the United States, hereby guarantees to deliver to the Exchange
Agent at one of its addresses set forth above, the certificates representing the
Initial Notes, together with a properly completed and duly executed Letter of
Transmittal (or facsimile thereof), with any required signature guarantees, and
any other documents required by the Letter of Transmittal within three New York
Stock Exchange, Inc. trading days after the date of execution of this Notice of
Guaranteed Delivery.
Name of Firm: __________________________________________________________________
 
                                       (Authorized Signature)
Address: ____________________________________  Title: __________________________
____________________________________________  Name: ____________________________
                                  (Zip Code)                           (Please
type or print)
Area Code and Telephone Number: ___________________  Date: _____________________
 
NOTE: DO NOT SEND INITIAL NOTES WITH THIS NOTICE OF GUARANTEED DELIVERY. INITIAL
             NOTES SHOULD BE SENT WITH YOUR LETTER OF TRANSMITTAL.


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