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                                                                  Exhibit 10.9
                                                                  EXECUTION COPY


                               AMENDMENT NO. 1 TO
                      EQUITY REGISTRATION RIGHTS AGREEMENT

                  This AMENDMENT NO. 1 TO THE EQUITY REGISTRATION RIGHTS
AGREEMENT, dated as of October 1, 2001 (this "AMENDMENT"), is made between
METROMEDIA FIBER NETWORK, INC., a Delaware corporation (the "COMPANY"), and
VERIZON INVESTMENTS INC., a Delaware corporation formerly known as Bell Atlantic
Investments, Inc. (the "PURCHASER"). Capitalized terms used herein that are not
defined herein shall have the meanings ascribed thereto in the Equity
Registration Rights Agreement (as defined below).

                                    RECITALS:

                  WHEREAS, as of October 7, 1999, the Company and the Purchaser
entered into that certain Securities Purchase Agreement (the "PURCHASE
AGREEMENT"), pursuant to which, among other things, the Company issued and sold
to the Purchaser shares of Class A common stock of the Company, par value $0.01
per share ("CLASS A COMMON STOCK");

                  WHEREAS, in connection with the issuance and sale of the Class
A Common Stock, the Company and the Purchaser entered into that certain Equity
Registration Rights Agreement, dated as of March 6, 2000 (the "EQUITY
REGISTRATION RIGHTS AGREEMENT"); and

                  WHEREAS, the Company and the Purchaser desire by this
Amendment to amend certain provisions of the Equity Registration Rights
Agreement.

                  NOW, THEREFORE, it is hereby agreed as follows:

                  SECTION 1.     Amendments to the Equity Registration Rights
                                 Agreement.

                  (a)      SECTION 1 of the Equity Registration Rights Agreement
is hereby amended by adding thereto the following new definitions in the
appropriate alphabetical location:

                           "PUBLIC RESALE" means a transfer of Registrable
                  Securities pursuant to (A) a bona fide secondary offering
                  registered under the Securities Act effectuated through the
                  exercise by the Purchaser or its permitted transferee of its
                  registration rights as contemplated by Section 2, 3 or 4 of
                  this Agreement or (B) a purchase agreement with a placement
                  agent or group of placement agents that contemplates the
                  immediate resale of securities by such placement agent
                  pursuant to the resale exemption provided by Rule 144A solely
                  to QIBs and other permitted purchasers under Rule 144A or in a
                  transfer permitted by Regulation S, or (C) bona fide "brokers
                  transactions" as permitted by or as otherwise permitted by the
                  exemption from registration of the resale of the shares of
                  Class A Common Stock provided by Rule 144.

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                           "QIB" means a "qualified institutional buyer" as
defined in Rule 144A.

                           "REGULATION S" means Regulation S promulgated under
the Securities Act.

                           "RULE 144A" means Rule 144A promulgated under the
Securities Act.

         (b) SECTION 1 of the Equity Registration Rights Agreement is hereby
amended by amending and restating the following definitions in their entirety to
read as follows:

                  "HOLDER" shall mean the Purchaser and any transferee of the
         Purchaser to whom Registrable Securities have been transferred, other
         than a transferee to whom such Registrable Securities have been
         transferred pursuant to a Public Resale and who continues to be
         entitled to the rights of a Holder hereunder.

                  "NOTES REGISTRATION RIGHTS AGREEMENT" shall mean that certain
         Notes Registration Rights Agreement, dated as of March 6, 2000, as
         amended by Amendment No. 1 to Registration Rights Agreement, dated as
         of October 1, 2001, by and among the Company and the Purchaser, as such
         agreement may be further amended, modified or supplemented from time to
         time.

                  "STOCKHOLDERS' AGREEMENT" shall mean the Amended and Restated
         Stockholders' Agreement, dated as of October 1, 2001, by and among the
         Company, the Purchaser and the stockholders of the Company listed on
         Schedule I thereto, as such agreement may be amended, modified or
         supplemented from time to time.

         (c) The second sentence of Section 2(a) of the Equity Registration
Rights Agreement shall be amended by inserting the following clause after "as
expeditiously as possible," and before "file with the SEC": "but in any event no
later than thirty (30) days (excluding any days which occur during a permitted
Blackout Period under Section 5 below) after receipt of a written request for a
Demand Registration,".

         (d) The proviso contained in the second sentence of Section 2(a) of the
Equity Registration Rights Agreement is hereby amended by replacing
"$100,000,000" with "$10,000,000."

         (e) Section 4 of the Equity Registration Rights Agreement shall be
renamed Section 4(a) and is hereby amended and restated in its entirety as
follows:

                           "4. (a) In the event that (i) the Purchaser desires
                  to resell any of the Registrable Securities held by it
                  (subject to the value threshold set forth in the proviso of
                  Section 2(a) above) or (ii) the Purchaser or one of its
                  Affiliates issues Securities (the "DERIVATIVE SECURITIES")
                  that by their terms are convertible into or exchangeable for
                  Registrable Securities and


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                  which will be issued in reliance on Regulation S and/or Rule
                  144A under the Securities Act, upon the written request of the
                  Purchaser, as promptly as practicable, but in any event no
                  later than 30 days after receipt of such request, Company
                  shall file with the SEC and thereafter use its reasonable best
                  efforts to cause to be declared effective as promptly as
                  practicable, but no later than 90 days after receipt of such
                  request, a registration statement (a "SHELF REGISTRATION
                  STATEMENT") on an appropriate form under the Securities Act
                  relating to such Registrable Securities or to the conversion
                  or exchange of the Derivative Securities, as the case may be,
                  from time to time in accordance with the methods and
                  distribution set forth in the Shelf Registration Statement and
                  Rule 415 under the Securities Act (hereafter, a "SHELF
                  REGISTRATION"). Company shall use its reasonable best efforts
                  to keep any Shelf Registration Statement continuously
                  effective in order to permit the prospectus included therein
                  to be lawfully delivered to holders of the Registrable
                  Securities or the Derivative Securities, as the case may be,
                  for a period of time until such time as all the Registrable
                  Securities have been resold or all the Derivative Securities
                  have been converted or exchanged, as the case may be, pursuant
                  thereto."

         (f) A new Section 4(b) of the Equity Registration Rights Agreement
shall be added to read as follows:

                           "(b) If (i) any Shelf Registration Statement has not
                  been declared effective by the SEC on or prior to the date on
                  which such Shelf Registration Statement is required to be
                  declared effective pursuant to Section 4(a), or (ii) the Shelf
                  Registration Statement is filed and declared effective but
                  shall thereafter cease to be effective at any time within the
                  time period required for effectiveness in Section 4(a) above
                  without being succeeded immediately by a post-effective
                  amendment to the Shelf Registration Statement that cures such
                  failure and that is itself immediately declared effective
                  (each such event referred to in clauses (i) and (ii), a
                  "REGISTRATION DEFAULT"), the Company shall pay liquidated
                  damages ("LIQUIDATED DAMAGES") to the Purchaser in an amount
                  equal to $0.01 per share of Registrable Securities or
                  Derivative Securities to be covered by such Shelf Registration
                  Statement, as the case may be, for each week or portion
                  thereof during which any Registration Default continues (other
                  than with respect to any period during which the Purchaser is
                  required to discontinue the disposition of Registrable
                  Securities pursuant to Section 5 hereof). The amount of such
                  Liquidated Damages shall increase on each 90-day anniversary
                  of the day the first Registration Default occurred by an
                  additional $0.01 per share of Registrable Securities or
                  Derivative Securities to be covered by such Shelf Registration
                  Statement, as the case may be, for each week or portion
                  thereof during which any Registration Default continues until
                  all Registration Defaults have been cured, up to a maximum
                  amount of Liquidated Damages of $0.05 per week or portion
                  thereof per share of Registrable Securities or Derivative
                  Securities to be covered by such Shelf Registration Statement,


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                  as the case may be. All accrued Liquidated Damages shall be
                  paid by wire transfer of immediately available funds or by
                  federal funds check on the last day of each four week period
                  to an account previously designated in writing to the Company
                  by the Purchaser. Following the cure of all Registration
                  Defaults relating to any particular Registrable Security or
                  Derivative Security, as the case may be, the accrual of
                  Liquidated Damages with respect to such Registrable Security
                  or Derivative Security, as the case may be, will cease.

                           All obligations of the Company set forth in the
                  preceding paragraph that are outstanding with respect to any
                  Registrable Security at the time such security ceases to be a
                  Registrable Security shall survive until such time as all such
                  obligations have been paid in full."

         (g) Section 6(n) of the Equity Registration Rights Agreement is hereby
amended by replacing "$100,000,000" with "$10,000,000."

         (h) Sections 6(a) through 6(n) of the Equity Registration Rights
Agreement are hereby amended by replacing "the Shelf Registration," in each
instance in which such clause appears, with "any Shelf Registration," and by
replacing "the Shelf Registration Statement," in each instance in which such
clause appears, with "any Shelf Registration Statement."

         (i) Section 9 of the Equity Registration Rights Agreement shall be
renamed Section 9(a), and a new Section 9(b) shall be added to read as follows:

                           "(b) The Company agrees (1) not to effect any public
                  or private offer, sale or distribution of any of its equity
                  securities or any class or series of its capital stock having
                  a preference in liquidation or with respect to dividends,
                  including a sale pursuant to Regulation D under the Securities
                  Act (other than any such sale or distribution of such
                  securities in connection with any merger or consolidation by
                  the Company or any subsidiary of the Company or the
                  acquisition by the Company or a subsidiary of the Company of
                  the capital stock or substantially all the assets of any other
                  Person or in connection with any employee stock option or
                  other benefit plan), during the 10-day period prior to, and
                  during the 90-day period beginning with, the effectiveness of
                  any Registration Statement to the extent timely notified in
                  writing by a Holder of Registrable Securities or the managing
                  underwriters in an underwritten offering (except as part of
                  such underwritten offering if permitted, or pursuant to
                  registrations on Forms S-4 or S-8 or any successor form to
                  such Registration Statement forms) and (2) during the
                  aforementioned period to use reasonable best efforts to cause
                  each Holder of each of its privately placed equity securities
                  or any class or series of its capital stock having a
                  preference in liquidation or with respect to dividends
                  purchased from the Company at any time on or after the date of
                  this Agreement to agree not to effect any public sale or
                  distribution of any such securities

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                  during such period, including a sale pursuant to Rule 144
                  under the Securities Act (except as part of such registration,
                  if permitted)."

         (j) The last sentence of the provision that is hereby renamed Section
9(a) of the Equity Registration Rights Agreement is hereby amended by inserting
"and if the Company and its directors, officers and other significant
stockholders enter into similar agreements" at the end of such sentence.

         (k) Section 13(d) of the Equity Registration Rights Agreement is hereby
amended and restated in its entirety to read as follows:

                  "(d) SUCCESSORS AND ASSIGNS. This Agreement shall inure to the
                  benefit of and be binding upon the successors and assigns of
                  each of the parties hereto including any person to whom
                  Registrable Securities are transferred, other than a
                  transferee to whom any such Registrable Securities have been
                  transferred pursuant to a Public Resale."

                  SECTION 2. Miscellaneous

         (a) This Amendment shall become effective upon its execution and
delivery by the Company and the Purchaser.

         (b) On and after the date hereof each reference in the Equity
Registration Rights Agreement to "this Agreement," "herein" or words of like
import shall mean and be a reference to the Equity Registration Rights Agreement
as amended hereby. No reference to this Amendment need be made in any instrument
or document at any time referring to the Equity Registration Rights Agreement. A
reference to the Equity Registration Rights Agreement in any such instrument or
document shall be deemed to be a reference to the Equity Registration Rights
Agreement as amended hereby. Except as expressly amended hereby, in all other
respects the Equity Registration Rights Agreement shall remain in full force and
effect.

         (c) This Amendment shall be governed by, construed and enforced in
accordance with the laws of the State of New York without giving effect to the
conflicts of laws provisions thereof. Each of the parties hereby submits to
personal jurisdiction and waives any objection as to venue in the County of New
York, State of New York. Service of process on the parties in any action arising
out of or relating to this Agreement shall be effective if mailed to the parties
in accordance with Section 13(c) of the Equity Registration Rights Agreement.
The parties hereto waive all right to trial by jury in any action or proceeding
to enforce or defend any rights hereunder.

         (d) This Amendment may be executed in any number of counterparts, each
of which shall be deemed to be an original, but all of which together shall
constitute but one and the same instrument.

                        [SIGNATURES APPEAR ON NEXT PAGE]

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

                                              METROMEDIA FIBER NETWORK, INC.


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



                                              VERIZON INVESTMENTS INC.


                                              By: /s/ Phil Seskin
                                                 -----------------------------
                                                 Name:  Phil Seskin
                                                 Title: Senior Vice-President