Document:

<PAGE>

                                                                  EXHIBIT 10.46

CONFIDENTIAL PORTION MARKED [*************] HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT AND FILED SEPARATELY WITH THE SECURITIES
AND EXCHANGE COMMISSION.

                                 AMENDMENT NO. 3
                                       TO
                          TRANSPORT SERVICES AGREEMENT

         This THIRD AMENDMENT ("Amendment No. 3") to the Transport Services
Agreement, effective as of February 8, 1999, as amended by Amendment No. 1
thereto dated as of September 29, 2000 and Amendment No. 2 thereto (as so
amended, the "TSA"), is made and entered into as of September 23, 2002, by and
among Williams Communications, LLC, a Delaware limited liability company
previously formed as Williams Communications, Inc. ("Williams"), SBC Operations,
Inc. and Southwestern Bell Communications Services, Inc., Delaware corporations
(collectively "SBCS"). Williams and SBCS may be referred to individually as
"Party" or collectively as the "Parties."

         WHEREAS, the Parties desire to amend the TSA as set forth below;

         NOW, THEREFORE, in consideration of the premises and covenants set
forth herein, Williams and SBCS agree as follows:

         1.       Amendments. The TSA is hereby amended as follows:

         (a)      Preamble. The preamble to the TSA is amended to read in its
                  entirety as follows:

                  "This Transport Services Agreement (this "Agreement") is made
                  as of the Effective Date, by and between Williams
                  Communications, LLC, previously formed as Williams
                  Communications, Inc., a Delaware limited liability company
                  ("Williams"), with its principal place of business at One
                  Technology Center, Tulsa, Oklahoma 74103, and SBC Operations,
                  Inc. and Southwestern Bell Communications Services, Inc.,
                  Delaware corporations (collectively "SBCS" and together with
                  Williams, the "Parties"), with their principal places of
                  business at 175 East Houston, San Antonio, Texas 78205, for
                  the provision of telecommunications services, subject to this
                  Agreement and as set forth in this Agreement."

         (b)      Section 1.1. Section 1.1 of the TSA is amended to add at the
                  end thereof a reference to a new Schedule P as follows:

                  "Schedule P - Market Index Pricing Methodology"

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 1 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

         (c)      Section 1.3. Section 1.3 of the TSA is amended to add or
                  restate in their entirety, as applicable, the following
                  definitions:

                  "'On-Net' - means a circuit traversing the Williams Network
                  both end points of which originate or terminate in a city with
                  a Williams designated Williams POP, Williams MAP, or such
                  other location where Williams maintains terminal equipment.

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                  'Williams MAP' - means a metropolitan access point that
                  extends the reach of the Williams' Network beyond a Williams'
                  POP to various points within a metropolitan area."

         (d)      Section 2. The first paragraph of Section 2 of the TSA is
                  amended to add the following two new sentences immediately
                  after the first sentence in Section 2:

                  "In addition, Williams may from time to time propose to offer
                  additional products or services under this Agreement. Upon
                  receipt of written notice from Williams of such a proposal,
                  representatives of each Party shall meet within 30 days, or
                  such longer period as the Parties may reasonably agree, in
                  order to negotiate in good faith (i) whether the addition of
                  such product or service shall be consistent with the
                  objectives of the TSA and the other Alliance Agreements, and,
                  if so, (ii) the appropriate characteristics and technical
                  specifications of such product or service."

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 2 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

         (e)      Section 3.1.4. Section 3.1.4 of the TSA is amended to read in
                  its entirety as follows:

                  "Off-Net Services. Off-Net Services are provided
                  [*****************************]. Notwithstanding anything to
                  the contrary herein, no Price Cap applies to Off-Net
                  Services."

         (f)      Section 3.9. The following new Section 3.9 is hereby added
                  immediately following Section 3.8 of the TSA:

                  "MFN Pricing. Notwithstanding this Section 3 or Section 3.4.3
                  of the MAA, SBCS Rates as determined pursuant to Schedule P
                  shall satisfy the requirements of this Section 3 with respect
                  to MFN Pricing and adjustments."

         (g)      Section 8. Section 8 of the TSA is amended to read in its
                  entirety as follows:

                  "8.1. Disconnection of Services. SBCS may disconnect any 1+
                  Voice Service on one business days notice without any
                  liability to Williams other than any termination liability
                  imposed by a Local Access Provider, including an SBC LEC
                  Affiliate or any other Third Party provider including an
                  Off-Net InterLATA Service provider, which shall be charged
                  [**************************]. SBCS may disconnect any
                  non-voice On-Net Service provided hereunder before the
                  expiration of the Minimum Term (as defined in Section 8.2) or
                  any renewal term, if applicable, by providing written
                  notification to Williams thirty (30) days in advance of the
                  effective date of disconnect. [******************************
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                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 3 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

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                  ****************************************]; plus (v) any
                  termination liability associated with Local Access, Off-Net
                  InterLATA Service, or any other Third Party provided Service
                  including those of an SBCS LEC Affiliate. These Third Party
                  charges shall be charged [***** *******************]. The
                  Parties agree that the actual damages in the event of such
                  disconnection would be difficult or impossible to ascertain,
                  and that the disconnection charge in this Section 8.1 is
                  intended, therefore, to establish liquidated damages and is
                  not intended as a penalty.

                           8.1.1 Williams will use commercially reasonable
                  efforts to notify SBCS on a monthly basis of all circuits with
                  a Minimum Term or renewal term which will expire within ninety
                  (90) days. If SBCS does not notify Williams of its intent to
                  disconnect or renew such circuits within such ninety 90 day
                  period, Williams will continue to provide such Service on a
                  month to month basis at the then existing rate applicable to
                  such circuit for sixty (60) days. If SBCS does not notify
                  Williams of its intent to disconnect or renew the circuit with
                  such sixty (60) day period, the circuit will renew for a one
                  year Minimum Term at the applicable one year rate.

                           8.2. Minimum Terms. The minimum term associated with
                  each non-voice Service will be as set forth on the Service
                  Order (the "Minimum Term"). SBCS may order non-voice Services
                  that have a monthly, a one year, or a three year Minimum Term.
                  If no Minimum Term is specified on the Service Order, the
                  Minimum Term shall be one year."

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 4 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

         (h)      Section 27.8. The following new Section 27.8 is hereby added
                  immediately following Section 27.7 of the TSA:

                  "With respect to a particular product or Service offered under
                  this Agreement, the QoS Standard referenced in the MAA is:
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         (i)      Section 35. The addresses for notices set forth in Section 35
                  of the TSA are amended to read in their entirety as follows:

                  "If to SBCS:      Southwestern Bell Communications
                                    Services, Inc.
                                    5850 West Las Positas Boulevard
                                    Pleasanton, CA 94588
                                    Attn:   Steven Grimm, President
                                    Telephone Number:  925 468-5275
                                    Facsimile Number:  925 468-4700

                  and               SBC Operations, Inc.
                                    530 McCullough
                                    San Antonio, TX  78215
                                    Attn:  Yno Gonzalez, Vice President
                                    Fax:        210 886-4040
                                    Telephone:  210 554-7124

                  with a copy       SBC Operations Inc.
                  (which shall      175 East Houston Street,
                  not constitute    San Antonio, TX  78205
                  notice) to:       Attn: T. Michael Payne,
                                    Senior Vice President & General Counsel
                                    Fax:        210-351-3737
                                    Telephone:  210-370-1790

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 5 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

                  If to Williams:   Williams Communications, LLC.
                                    One Technology Center
                                    Tulsa, OK  74103
                                    Attn:  Contract Management
                                    Telephone Number: (918) 547-6000
                                    Facsimile Number: (918) 547-0460

                  with a copy       Williams Communications, LLC.
                  (which shall      One Technology Center
                  not constitute    Tulsa, OK  74103
                  notice) to:       Attn:   General Counsel
                                    Telephone Number: (918) 547-5057
                                    Facsimile Number: (918) 547-2360"

         (j)      Schedule P. A new Schedule P, in the form set forth as
                  Schedule P to this Amendment No. 3, is hereby added to the
                  TSA.

         2. Effect. Except as herein expressly amended, the TSA and any other
documents executed and delivered in connection therewith are each ratified and
confirmed in all respects and shall remain in full force and effect in
accordance with their respective terms. Upon the effectiveness of this Amendment
No. 3, each reference in the TSA to "this Agreement," "hereunder," "hereof,"
"herein," or words of like import shall mean and be a reference to the TSA as
amended hereby, and each reference to the TSA in any other document, instrument
or agreement executed and/or delivered in connection with the TSA shall mean and
be a reference to the TSA as amended hereby.

         3. Conditions to Effectiveness. This Amendment No. 3 shall be effective
immediately, subject only to the following conditions subsequent: (i) the filing
by all of the Plan Proponents (as such term is defined in the Second Amended
Joint Chapter 11 Plan of Reorganization of Williams Communications Group, Inc.
("WCG") and CG Austria, Inc. ("CG Austria") filed on August 12, 2002 with the
United States Bankruptcy Court for the Southern District of New York (the
"Bankruptcy Court"), in the Chapter 11 Case No. 02-11957 (the "Plan of
Reorganization")), with the written consent of The Williams Companies, Inc., of
modifications to the Plan of Reorganization and an amended Investment Agreement,
Stockholders Agreement and New WCG Charter (as such terms are defined in the
Plan of Reorganization), each substantially in the forms attached as Exhibit D
to that certain Stipulation and Agreement (the "Stipulation") dated as of
September 23, 2002 (the "Stipulation Date") among Williams, CG Austria, WCG, SBC
Communications Inc. ("SBC") and the other parties thereto, (ii) the Plan of
Reorganization shall have been confirmed by the Bankruptcy Court and the
Effective Date (as defined in the Plan of Reorganization) shall have occurred on
or before October 14, 2002; (iii) the Bankruptcy Court shall have entered an
order that shall have become a Final Order (as defined in the Plan of
Reorganization) on or before October 14, 2002,

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 6 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

approving and authorizing WCG's and CG Austria's entering into and performing
the Stipulation; and (iv) the Plan of Reorganization shall not have been
modified or amended in any manner that would affect SBC or that would alter the
Plan of Reorganization in any material respect without the express prior written
consent of SBC, which shall not be unreasonably withheld (except that the Plan
of Reorganization may be amended as set forth in Exhibit D to the Stipulation
without further consent from SBC). The Parties each acknowledge and agree that
the amendments and provisions set forth in Sections 1 and 2 above are not
effective until the conditions subsequent set forth in clauses (i) through (iv)
in this Section 3 have been satisfied or waived in writing by SBC. Subject to
the immediately following sentence, in the event that any of these conditions
subsequent shall fail to have been satisfied or waived by SBC in writing on or
before October 14, 2002 (subject to extension as set forth below), then this
Amendment No. 3 shall be null and void, ab initio, and the Parties shall be
restored to their respective rights and obligations as in existence immediately
prior to the Stipulation Date. In the event that Section 4.2 of the Plan of
Reorganization is amended to extend the date of October 14, 2002 to a later date
(but no later than November 14, 2002 except as provided in the immediately
following sentence), this Section 3 shall automatically (without any action of
the Parties or other signatories hereto) be amended so that references to
October 14, 2002 herein are replaced with reference to the date in Section 4.2
of the Plan of Reorganization, as so amended; provided, however, that no such
amendment will be effective if, at the time of such amendment to the Plan of
Reorganization, the Investment Agreement, the Restructuring Agreement or the TWC
Settlement Agreement (as such terms are defined in the Plan of Reorganization)
shall have been terminated. In the event that all of the conditions subsequent
set forth in this Section 3 shall have been satisfied on or before November 14,
2002, except that the Effective Date shall not have occurred and none of the
Investment Agreement, the Restructuring Agreement or the TWC Settlement
Agreement shall have been terminated, then this Amendment No. 3 shall not
terminate if the Effective Date occurs on or before January 13, 2003; provided
that this Amendment No. 3 shall be null and void, ab initio, and the Parties
shall be restored to their respective rights and obligations as in existence
immediately prior to the Stipulation Date (i) if the Effective Date shall not
have occurred by January 13, 2003 or (ii) upon termination of the Investment
Agreement, the Restructuring Agreement or the TWC Settlement Agreement.

         4. Representations and Warranties. Each Party to this Amendment No. 3
represents and warrants to the other as follows:

                  (a) The execution, delivery and performance by such party of
                  this Amendment No. 3 and the performance by such party of the
                  TSA as amended hereby (i) have been duly authorized by all
                  necessary corporate or other action and (ii) do not and will
                  not contravene its organizational documents or any applicable
                  law. Such Party has all requisite corporate or limited
                  liability company power and authority to enter into this
                  Amendment No. 3 and to perform its obligations hereunder and
                  under the TSA, as amended hereby.

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 7 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

                  (b) This Amendment No. 3 and the TSA, as amended hereby,
                  constitute the legal, valid and binding obligations of such
                  party, enforceable against such party in accordance with their
                  terms.

         5. Counterparts. This Amendment No. 3 may be executed in any number of
counterparts with the same effect as if all Parties hereto had signed the same
document. All counterparts shall be construed together and shall constitute one
instrument. Any such counterpart may be executed by facsimile transmission.

         6. Headings. Section and paragraph headings herein are included for
convenience of reference only and shall not constitute a part of this Amendment
No. 3 for any other purpose.

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 8 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

         IN WITNESS WHEREOF, the Parties hereto have executed this Amendment No.
3 to the TSA effective as of the date the last Party to this Amendment No. 3
signs below.

                               WILLIAMS COMMUNICATIONS, LLC

                               By :  /s/Frank Semple
                                   --------------------------------------------
                               Name:
                               Title:

                               ------------------------------------------------
                               (DATE)

                               SBC OPERATIONS INC.

                               By :  /s/ Ross K. Ireland
                                   --------------------------------------------
                               Name:  Ross K. Ireland
                               Title: President and Chief Executive

                                      9/24/02
                               ------------------------------------------------
                               (DATE)

                               SOUTHWESTERN BELL COMMUNICATIONS SERVICES, INC.

                               By :  /s/ Steven M. Grimm
                                   --------------------------------------------
                               Name:  Steven M. Grimm
                               Title:   President, SBC Long Distance

                                      9/23/02
                               ------------------------------------------------
                               (DATE)

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                  Page 9 of 9

<PAGE>

AMENDMENT NO. 3 TO TRANSPORT SERVICES AGREEMENT, AS AMENDED

                                   SCHEDULE P

   SIX-PAGE SCHEDULE HAS BEEN OMITTED PURSUANT TO A REQUEST FOR CONFIDENTIAL
  TREATMENT AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION.

                             PROPRIETARY INFORMATION

This information contained in this Amendment No. 3 is not for use or disclosure
outside SBC, Williams, their affiliated companies and their third party
representatives, except under written agreement by the contracting Parties.

                                        i<PAGE>
                                                                   EXHIBIT 10.47

EXECUTION COPY                                                      CONFIDENTIAL

CONFIDENTIAL PORTION MARKED [*************] HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT AND FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION.

                              FIBER LEASE AGREEMENT

                              dated April 26, 2002

                                     between

                     Metromedia Fiber Network Services, Inc.

                                       and

                          Williams Communications, LLC

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                                TABLE OF CONTENTS

<Table>
<S>                                                                                             <C>
ARTICLE 1.  DEFINITIONS..........................................................................1
ARTICLE 2.  TERMINATION OF FIBER LEASE...........................................................3
ARTICLE 3.  GRANT OF LEASE AND BUILDING ACCESS...................................................4
ARTICLE 4.  CONSIDERATION; FEES..................................................................6
ARTICLE 5.  DELIVERY AND ACCEPTANCE..............................................................8
ARTICLE 6.  COLLOCATION AND MAINTENANCE.........................................................11
ARTICLE 7.  AUTHORIZATIONS......................................................................11
ARTICLE 8.  Intentionally Omitted...............................................................11
ARTICLE 9.  INTERCONNECTION OF LESSEE'S SYSTEM..................................................11
ARTICLE 10. USE OF THE LESSEE FIBER.............................................................13
ARTICLE 11. PAYMENT TERMS.......................................................................14
ARTICLE 12. INDEMNIFICATION.....................................................................14
ARTICLE 13. INSURANCE...........................................................................15
ARTICLE 14. TAXES AND FRANCHISE, LICENSE AND PERMIT FEES........................................16
ARTICLE 15. NOTICE..............................................................................17
ARTICLE 16. CONFIDENTIALITY AND PUBLICITY.......................................................18
ARTICLE 17. DEFAULT.............................................................................19
ARTICLE 18. FORCE MAJEURE.......................................................................20
ARTICLE 19. ARBITRATION.........................................................................21
ARTICLE 20. ASSIGNMENT..........................................................................21
ARTICLE 21. RULES OF CONSTRUCTION...............................................................22
ARTICLE 22. REPRESENTATIONS AND WARRANTIES......................................................24
ARTICLE 23. LIMITATIONS OF LIABILITY............................................................25
ARTICLE 24. AUDIT RIGHTS........................................................................26
ARTICLE 25. IMPROPER PAYMENTS PROHIBITED........................................................26
ARTICLE 26. ENTIRE AGREEMENT; AMENDMENT; EXECUTION..............................................27
</Table>

EXHIBITS:

EXHIBIT A FIBER TESTING SPECIFICATIONS
EXHIBIT B LESSEE FIBER AND MAPS
EXHIBIT C BUILDINGS
EXHIBIT D FORM OF AS-BUILTS
EXHIBIT E MFN DATA CENTERS
EXHIBIT F CONSTRUCTION SPECIFICATIONS

                                        i

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                                 LEASE AGREEMENT

            THIS LEASE AGREEMENT (this "Agreement") is made as of the 26 day
of April, 2002, (the "Effective Date") by and between METROMEDIA FIBER NETWORK
SERVICES, INC., a Delaware corporation ("MFN") and WILLIAMS COMMUNICATIONS, LLC,
a Delaware limited liability company ("Lessee").

                                   BACKGROUND

A. MFN owns or controls metropolitan and intercity fiber optic communication
systems located in the continental United States and Europe (collectively, the
"MFN System");

B. MFN desires to grant to Lessee a lease ("Lease") in certain optical fibers in
the MFN System and Lessee desires to accept a Lease in such fibers, all upon the
terms and conditions set forth in this Agreement.

                               TERMS OF AGREEMENT

Accordingly, in consideration of the mutual promises set forth below and other
good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereby agree as follows:

ARTICLE 1. DEFINITIONS

The following terms shall have the stated definitions in this Agreement.

"ACCEPTANCE DATE" means the date when Lessee delivers (or is deemed to have
delivered) a notice of acceptance with respect to each delivery of Lessee Fiber
and/or Buildings as further described in Section 5.3.

"AFFILIATE" means, with respect to any entity, an entity controlling, controlled
by, or under common control with such entity by means of direct or indirect
equity ownership or otherwise. As used in this Agreement, "control" shall mean
possession, directly or indirectly, of the power to direct or cause the
direction of the management and policies of a person or entity, whether through
the ownership of voting securities, by contract or otherwise.

"BUILDING" means any commercial building, central office, MFN Data Center or
point-of-presence ("POP").

"BUILDING ACCESS" is defined as Lessee's use of a MFN-owned fiber optic lateral
connection and termination facilities for the purpose of interconnecting the
Lessee Fiber at a Building.

                                       1
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"BUILDING ACCESS PAYMENT" is the monthly recurring fee payable by Lessee for
Building Access as set forth in Section 4.2.

"CONFIDENTIAL INFORMATION" shall have the meaning set forth in Section 16.1.

"COSTS" means actual and directly related costs accumulated in accordance with
the established accounting procedure used by MFN or Lessee or their respective
contractors or subcontractors, as the case may be, which costs include the
following: (a) labor costs, including wages, salaries, benefits and overhead
allocable to such labor costs (Lessee's or MFN's overhead allocation percentage
shall not exceed the lesser of (i) the percentage such party allocates to its
internal projects or (ii) one hundred and thirty percent (130%), and (b) other
direct costs and out-of-pocket expenses on a pass-through basis (e.g.,
equipment, materials, supplies, contract services, etc.).

"DATA CENTER ACCESS" refers to the interconnection of Lessee Fiber with an MFN
Data Center.

"DELIVERY DATE" means each date MFN delivers or previously delivered Lessee
Fiber and/or Buildings to Lessee, including, with respect to the Lessee Fibers,
all test deliverables.

"DEMARCATION POINT" means the point where MFN's installation, maintenance and
operation obligations terminate as further described in Article 9.

"DIVERSITY" means the provision of physically separated optical facilities that,
when equipped with suitable optronics, are capable of providing an alternate
transmission path without human or mechanical intervention. The alternate
facilities shall, except at each Demarcation Point, have at least thirty (30)
feet of separation in any direction and shall not be on the same poles, towers,
river crossings, bridges, viaducts, elevated walkways, or similar structures.

"EQUIPMENT" means Lessee's electronic, optronic and power equipment necessary
for the operation of the Lessee Fiber.

"EXPIRATION DATE" shall have the meaning set forth in the definition of "Term"
below.

"FACILITY OWNERS/LENDERS" means any entity (other than MFN): (a) owning any
portion of the System or any property or security interest therein, (b) leasing
to MFN, or providing an Lease to MFN in, any portion of the System, or (c) that
is a lender (including any party holding legal title or a security interest in
the MFN System as a lessor or a creditor) with respect to MFN or any Affiliates
of MFN.

"FIBER ACCEPTANCE TESTING" shall have the meaning set forth in Section 5.3(a).

"FIBER TESTING SPECIFICATIONS" are set forth in Exhibit A.

                                       2
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"LESSEE FIBER" shall have the meaning set forth in Section 3.1.

"MFN DATA CENTER" refers to the Internet data centers (f/n/a AboveNet data
centers and not including any locations owned by PAIX.net) owned or controlled
by MFN and listed in Exhibit E.

"PRODUCT ORDER" is defined in Section 3.4.

"RELEASED PARTY" means each of the following:

         (a) any Affiliates of the other party and any Facility Owners/Lenders;

         (b) any employee, officer, director, stockholder, partner, member, or
         trustee of the other party or of its Affiliates or Facility
         Owners/Lenders; or

         (c) assignees of the entities included in the above subparagraphs (a)
         or (b) and any employee, officer, director, stockholder, partner,
         member, or trustee of such assignees.

"RIGHT-OF-WAY AUTHORIZATIONS" means any underlying agreements, easements,
permits, or licenses, by which MFN obtains rights to perform its obligations
hereunder with respect to the MFN System, Buildings and Lessee Fiber from:

         (a) underlying owners of real or personal property, or right-of-way
         holders,

         (b) grantors of IRU or other rights or licenses with respect to all or
         a portion of its System,

         (c) parties granting duct usage and pole attachment rights, and

         (d) any governmental authority (including franchising agencies,
         environmental regulation agencies, and public utility commissions).

"SPLICE POINT" is defined in Section 9.2.

"TERM" begins on the Effective Date and expires 20 years after the latest
Acceptance Date (the "Expiration Date") under this Agreement.

"UNRESTRICTED FIBER" is defined in Section 20.3(b).

ARTICLE 2. TERMINATION OF FIBER LEASE

This Agreement cancels and replaces the Fiber Lease Agreement dated September
16, 1999 between the parties covering the MFN System, including all amendments
thereto (the "Fiber

                                       3
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Lease"). Immediately upon the Effective Date, the Fiber Lease is terminated and
of no further force and effect.

ARTICLE 3. GRANT OF LEASE AND BUILDING ACCESS

3.1 LESSEE FIBER. Unless otherwise converted to an IRU pursuant to Section 3.6,
MFN grants to Lessee a Lease in 43,040 fiber miles in the MFN System (the
"Lessee Fiber") for a period of 20 years beginning on the Acceptance Date for
each segment. Such Lessee Fiber is identified by segment in Exhibit B. MFN shall
provide Lessee with maps sufficiently depicting the routes of the Lessee Fiber
within 60 days of the Effective Date. To the extent the Acceptance Date for any
Lessee Fiber has not occurred as of the Effective Date, MFN has the obligation
to design, engineer, install, and construct or acquire such Lessee Fiber. Unless
otherwise accepted by Lessee, all Lessee Fiber shall provide Diversity. Lessee
agrees to pay the fees set forth in Section 4.1 for the Lessee Fibers.

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3.2 LEASE LIMITATIONS. The Lease granted to Lessee hereunder and any rights
granted by Lessee to third party users, are subject to all Right-of-Way
Authorizations applicable to the MFN System and the Buildings. Lessee will
adhere to the requirements of all such Right-of-Way Authorizations. The Lease of
the Lessee Fiber hereunder does not convey any legal title to any real or
personal property, including the fibers, cable, or the MFN System. This Lease
does not include any Equipment used to transmit capacity over, or to "light,"
the Lessee Fiber.

3.3 BUILDING ACCESS. MFN will provide Building Access to the Buildings listed in
Exhibit C. To the extent the Lessee Fiber does not terminate at the Buildings
listed in Exhibit C as of the Effective Date, MFN has the obligation to design,
engineer, install, and construct or acquire fiber and terminate such fiber at
such Buildings. All such terminations established by MFN shall comply with the
relevant Fiber Testing Specifications (including the splice loss and optical
fiber specifications) set forth in Exhibit A and with relevant
telecommunications industry practices. MFN shall use commercially reasonable
efforts to provide all Building terminations with Diversity. In the event that a
termination in a Building does not have Diversity, then MFN shall give notice to
Lessee and the reduction in the Building Access Payment set forth in Section
4.2(c)

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shall apply to such termination. Lessee agrees to pay the Building Access
Payment set forth in Section 4.2 for Building Access.

3.4 ADDITIONAL BUILDINGS. Except as provided in Section 3.5, below, MFN is only
obligated to provide Building Access at those locations listed in Exhibit C.
However, at any time during the Term, Lessee may request that MFN connect the
Lessee Fibers to additional Buildings under the terms and conditions of this
Agreement. Within 15 days of Lessee's request, if accepted, MFN will provide
Lessee with its then-current order form specifying the Building Access Payment,
any non-recurring charges (as set forth in Section 4.3), and the anticipated
Delivery Date of the requested Building (each such order form a "Product
Order"). Lessee must sign the Product Order and return to MFN within 15 days.
All future Product Orders signed by both parties are governed by and
incorporated by reference into this Agreement.

Alternatively, if MFN rejects the Building request or Lessee rejects the Product
Order, Lessee has the option of either:

(a) requesting that MFN participate with Lessee in a joint construction effort
to make such interconnection pursuant to a separate agreement negotiated between
the parties that shall not require a Building Access Payment; or

(b) requesting that MFN construct the lateral connection as Lessee's contractor
pursuant to a separate agreement negotiated between the parties. If MFN accepts,
Lessee will own the lateral connection and related facilities and Lessee will
pay the one time charge for the connection at Cost; or

(c) constructing and owning the lateral connection to the Building and
interconnecting to the MFN backbone at a Splice Point in accordance with Section
9.2, below. Lessee, in its good faith discretion, may permit MFN to utilize
Williams' interconnection facilities to connect to a Building. There is no
Building Access Payment associated with Splice Point interconnection.

3.5 MANHATTAN BUILDING. Upon Lessee's request, MFN agrees to conduct a
feasibility study, at Williams Communications sole cost and expense, to
determine if MFN can provide connectivity from a manhole at the southeast corner
of 11th Avenue and 27th Street (near 111 E. 8th St.) to Lessee's POP located at
601 W. 26th Street on the sixth floor and continuing from the POP to Lessee POP
in 60 Hudson in New York, New York. If feasible, MFN will perform all necessary
construction at Williams Communications' sole cost and expense.

3.6 CONVERSION TO IRU. At any time during the Term, upon the request of Lessee
and Lessee's payment to MFN of the net present value of the Lease Payments and
Building Access Payments calculated based upon a mutually agreed upon discount
rate, MFN shall grant to Lessee an Indefeasible Right of Use to the Lessee
Fibers and Building terminations equal to the remaining term of this Agreement.

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ARTICLE 4. CONSIDERATION; FEES

4.1 LEASE PAYMENTS. MFN represents that the fiber miles set forth in Exhibit B,
are either the actual fiber miles (calculated as the route miles traversed by
the Lessee Fiber multiplied by the number of Lessee Fibers on the route) or a
bona fide estimate thereof, such estimate calculated utilizing OTDR distances
less ten percent (10%). Lessee shall make monthly payments to MFN in advance
during the Term, in an amount calculated as [*****] PER FIBER MILE PER MONTH
("Lease Payments") based on the fiber miles set forth in Exhibit B, beginning
upon the Effective Date or on the Acceptance Date of the Lessee Fiber set forth
in Exhibit B if later than the Effective Date.

4.2 BUILDING ACCESS PAYMENTS. Except as provided in Section 3.4, in exchange for
Building Access at each Building, Lessee shall make Building Access Payments to
MFN in advance.

         (a) The Building Access Payment is calculated as follows:

<Table>
<Caption>
                     Total                                      Price per
                Number of fibers                                fiber per
                   terminated                                interconnection
                ----------------                             ---------------
<S>                                                          <C>
                        [*                                         ****]
                        [*                                          ***]
                        [*                                          ***]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
                        [**                                      ******]
</Table>

         (b) The Building Access Payment for each termination in a Building is
reduced by [***] for the period beginning on the Acceptance Date of the Building
and ending on the first anniversary of such acceptance.

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            (c) If MFN does not offer Diversity in the termination to a
Building, the Building Access Payment for that Building shall be reduced by
[***] (for a total of [***] for the first year) until such time as Diversity is
provided, if ever.

            (d) Lessee may cancel a Building after 24 months of Building Access
Payments for such Building by providing at least 30 days prior written notice to
MFN, provided that Williams maintains a minimum of 40 Buildings during the Term.

            (e) The parties agree that MFN may splice up to a full ribbon of
cable at each Building even if Lessee requests interconnection of less than 12
fibers. Lessee is not obligated to pay the Building Access Payment for any extra
fibers spliced over and above the number of fibers ordered, and Lessee may still
port such fibers under Section 3.1.

4.3. NON-RECURRING CHARGES. Upon Product Order execution, MFN will invoice and
Lessee agrees to pay non-recurring charges agreed upon in the Product Order.
Non-recurring charge will include:

            (a) MFN's Costs associated with splicing, testing and/or
constructing laterals at new Buildings provided pursuant to Section 3.4:

            (b) Intra-building riser cabling and construction pursuant to
Section 5.6; and

            (c) MFN's Costs associated with Splice Point interconnection
pursuant to Section 9.2.

4.4 ADDITIONAL CHARGES. MFN will invoice and Lessee agrees to pay for all other
additional fees and charges contemplated by this Agreement or set forth in a
signed Product Order for services.

4.5 PAYMENT TERMS. Building Access Payments and Lease Payments commence on the
first day of the month beginning with the month after the Acceptance Date of the
relevant Lessee Fiber and/or Building, except that the first payment shall
include payment from the Acceptance Date to the last day of the month during
which the Acceptance Date occurs, as well as payment for the first full month
after the Acceptance Date. Lessee shall continue making such payments through
the first day of the month in which the Expiration Date occurs, unless the
Agreement is terminated prior to the Expiration Date as herein provided. All
payments are payable in accordance with Article 11.

4.6 NO BUILDING ACCESS PAYMENTS AT POPS. MFN will not charge a Building Access
Payment for termination within MFN POPs where Lessee is collocating with MFN, or
at Lessee's POPs. In addition, provided that Lessee is making Building Access
Payments in connection with any Building, Lessee shall have the right to route
other interconnections through

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the Demarcation Point for such Building without paying any additional Building
Access Payment. To be sure, however, MFN is not obligated to provide Williams
with any intra-building riser fiber to facilitate Lessee's other
interconnections.

ARTICLE 5. DELIVERY AND ACCEPTANCE

5.1 DELIVERY. To the extent not already delivered by MFN and accepted by Lessee,
MFN will use commercially reasonable efforts to deliver the Lessee Fiber and
Buildings by the scheduled Delivery Date for each stated in Exhibit B and
Exhibit C, respectively. In the event MFN anticipates a failure to deliver any
of the Lessee Fiber or Buildings by the scheduled Delivery Date, the parties
will designate representatives to meet and review the status of the delivery. If
the scheduled Delivery Date for any segment of Lessee Fiber or a Building is in
fact delayed, such delay will be considered a triggering event for the accrual
of liquidated damages to the Lessee as follows:

         (a) Subject to subsections (b), (c) and (d) below, and provided the
delay is not caused in whole or in part by Lessee, Lessee is entitled to a
credit against monthly charges in an amount equal to $18 per fiber mile of the
segment of Lessee Fiber for which the Delivery Date is delayed per month until
such time as such segment is delivered, and a credit against monthly charges in
an amount equal to $1,600 per delayed Building per month until delivered
("Liquidated Damages");

         (b) Liquidated Damages for each segment of Lessee Fibers is limited to
50% of the present value of the total monthly charges payable based on [******]
per fiber mile (using a discount factor of 10%) associated with the fiber miles
for the delayed segment. As an example, if a segment consisting of [***] fiber
miles is delayed under the Agreement, the present value of monthly charges for
that segment is [***********], and the total maximum Liquidated Damages payable
to Lessee for the delayed segment, regardless of duration of delay is
[***********]. Partial months of delay will be credited on a daily pro-rated
basis;

         (c) Liquidated Damages for Lessee Fiber for all delays are limited to
25% of the then-current monthly invoicing of [******] per fiber mile to Lessee.
As an example, if MFN is currently billing Lessee [********] per month, Lessee
is entitled to a maximum of [********] per month in Liquidated Damages,
regardless of the number of delayed segments;

         (d) Lessee may terminate the Agreement with respect a delayed segment
of Lessee Fibers or a delayed Building upon 15 days prior written notice to MFN,
unless and until delivery actually occurs. Upon termination, Liquidated Damages
will cease to accrue for the terminated segments and/or Buildings, and MFN has
no further payment obligations with respect to such segment.

         The parties agree that the Liquidated Damages represent a reasonable
estimate of anticipated damages incurred by Lessee in the event of a delay of a
segment of Lessee Fiber or a

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Building. The Liquidated Damages and termination of a segment with a reduction
of payment obligations are the sole and exclusive remedies of the Lessee and the
sole and exclusive liabilities of MFN with respect to a delivery delay, and
provided each party has complied with the terms of this Section 5.1, under no
circumstances will a delay in the Delivery Date for a segment of Lessee Fiber or
a Building be considered a default.

5.2 OBLIGATION TO PROVIDE COMPLETION NOTICE. MFN shall promptly notify Lessee in
writing of the date upon which MFN has completed connecting a Building.

5.3 ACCEPTANCE AND TESTING OF FIBERS

         (a) MFN TESTING. MFN shall give notice to Lessee at least 21 days prior
to the date MFN intends to begin testing of Lessee Fiber ("Fiber Acceptance
Testing"). Lessee shall have the right, but not the obligation, to have a
representative present at such Fiber Acceptance Testing. MFN shall perform Fiber
Acceptance Testing of the Lessee Fiber and provide test deliverables to Lessee
in accordance with Exhibit A. The provisions of this Subsection 5.3 are intended
to apply to the delivery of Lessee Fiber and the delivery of Buildings and the
Acceptance Date for both are conditioned on the acceptance of such test results.

         (b) OBJECTIONS TO TEST RESULTS. Lessee shall have 21 calendar days
after receipt of test deliverables to provide MFN written notice of any bona
fide determination by Lessee that the Lessee Fiber does not meet the Fiber
Testing Specifications. Such notice shall identify the specific data that
indicate a failure or other specific reasons that such Lessee Fiber fail to meet
the Fiber Testing Specifications.

         (c) RESPONSE TO OBJECTIONS. Upon receiving written notice from Lessee
pursuant to Section 5.3(b), MFN shall either: (i) expeditiously take such action
as shall be reasonably necessary to cause such portion of the Lessee Fiber to
meet the Fiber Testing Specifications and then re-test the Lessee Fiber in
accordance with the provisions of this Article; or (ii) provide Lessee written
notice that MFN disputes Lessee's determination that the Lessee Fiber does not
meet the Fiber Testing Specifications. After taking corrective actions and
re-testing the Lessee Fiber, MFN shall provide to Lessee a copy of the new test
deliverables and Lessee shall again have all rights provided in this Article
with respect to such new test deliverables. The cycle described above of
testing, taking corrective action and re-testing shall take place until the
Lessee Fiber is accepted.

         (d) INDEPENDENT TESTING. If MFN provides notice to Lessee pursuant to
Subsection 5.3(c)(ii), Lessee shall within five calendar days of such notice
designate by written notice to MFN the names and addresses of three reputable
and independent fiber optic testing companies. MFN shall designate one of such
companies to conduct an independent re-test of the Lessee Fiber for the relevant
Lessee Fiber. If, after such re-testing, the testing company determines that the
Lessee Fiber so tested: (i) meet the Fiber Testing Specifications, then Lessee
shall pay the testing company's charges for performing the testing and the
Acceptance Date for

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the relevant Lessee Fiber shall be 21 calendar days after the date that MFN
originally provided its test deliverables; or (ii) do not meet the Fiber Testing
Specifications, then MFN shall pay the testing company's charges for performing
the testing and shall perform the corrective action and re-testing set forth in
Subsection 5.3(c)(i).

5.4 ACCEPTANCE. Unless Lessee provides a timely written objection pursuant to
Section 5.3, the Acceptance Date for each delivery occurs on the twenty-first
calendar day after the Delivery Date, or, if earlier, the date Lessee (a)
provides written acceptance of the Lessee Fiber or Building or (b) commences use
of the Lessee Fiber or Building. Any failure by Lessee to accept or reject the
Lessee Fiber within the 21-day period, or any use of the Lessee Fiber by Lessee
Fiber for any purpose other than testing, constitutes acceptance for purposes of
this Agreement and Lessee is deemed to have accepted upon such use or on the
22nd day after the Delivery Date.

5.5 AS-BUILT DRAWINGS. MFN will provide to Lessee, within 180 days of the
Acceptance Date, as-built drawings of Lessee Fiber in the format described in
Exhibit D to this Agreement.

5.6 INTRABUILDING EXTENSIONS. Lessee may elect to obtain either fiber optic or
metallic (e.g., coaxial cable or copper twisted pair) extensions between a MFN
Demarcation Point at a Building and another point within the same Building. Upon
written request for either such extension setting forth the design and
terminating location of such extension, MFN shall, at its sole discretion and in
accordance with its then-standard order intervals, either (a) construct a
Lessee-owned riser for a nonrecurring charge equal to its Cost; (b) designate at
least one, but up to three, reputable MFN-approved contractors authorized to
perform such work, in which case MFN shall have no responsibility for such
extension and Lessee shall deal directly with any such contractor for
Lessee-owned risers; or (c) provide MFN-owned riser at MFN's then-current
charge. MFN shall reasonably cooperate with any such approved contractors
selected by Lessee to allow them to perform such work.

5.7 USE OF PARTIALLY COMPLETED SEGMENT. If MFN has not delivered a segment or
ring of Lessee Fiber by the scheduled Delivery Date, but some portions of the
segment are available for use, MFN shall, upon request of Lessee, permit Lessee
to use such available portions and Lessee shall pay a pro rata share of the
lease payment with respect to the Lessee Fibers in such segment. In addition, in
the event that Lessee elects to accept a portion of a segment of Lessee Fiber
prior to the time that a complete segment or ring is available for use, the late
fee payment set forth in Section 5.1 shall be reduced in proportion to the
Lessee Fibers in the segment or ring being utilized.

5.8 EARLY DELIVERY. In the event that MFN has any Lessee Fibers available prior
to the scheduled Delivery Date, MFN may give notice to Lessee, offering to
deliver such Lessee Fibers prior to the scheduled Delivery Date therefore.
Lessee shall advise MFN whether or not Lessee desires to begin using such Lessee
Fibers prior to the scheduled Delivery Date. If Lessee elects to begin such use
prior to the scheduled Delivery Date, the Term of such Lessee Fibers and payment
obligations shall commence upon the actual Acceptance Date thereof.

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ARTICLE 6. COLLOCATION AND MAINTENANCE

Collocation, operation and maintenance of the Lessee Fiber is governed by the
Collocation and Maintenance Agreement, dated contemporaneously with this
Agreement.

ARTICLE 7. AUTHORIZATIONS

7.1 MAINTAINING AUTHORIZATIONS. MFN shall use commercially reasonable efforts to
maintain, renew, or replace the Right-of-Way Authorizations during the Term. If
MFN determines it is not commercially reasonable to maintain, renew or replace
any of its existing Right-of-Way Authorizations during the Term, then MFN shall
give notice to Lessee and shall cooperate with Lessee, at Lessee's written
request, to attempt to maintain, renew or replace such Right-of-Way
Authorizations, at Lessee's sole Cost. During the last three years of the Term,
upon written notice from Lessee requesting such information, MFN shall promptly
provide written notice of the status (including any potential or pending
terminations or expirations) of Right-of-Way Authorizations relating to the
Lessee Fiber, including but not limited to whether or not MFN intends to extend
or renew any Right-of-Way Authorizations. In the event that during the Term any
Right-of-Way Authorization expires or is terminated and is not replaced, Lessee
shall have the right upon 30 days prior written notice to MFN, to terminate the
Lease with respect to the Lessee Fiber affected by such expired or terminated
Right-of-Way Authorization. Upon such termination, Lessee's obligation to make
any Lease payments with respect to which the Lease has been terminated shall
expire.

7.2 EXTENSION OF LEASE TERM. To the extent MFN has elected to maintain or extend
or replace Right-of-Way Authorizations with respect to this Lease beyond the
Term, Lessee may request an extension of the Term of such Lease, and MFN agrees
to negotiate with Lessee with respect to such extension, but MFN shall have no
obligation to grant any such extension.

ARTICLE 8. INTENTIONALLY OMITTED

ARTICLE 9. INTERCONNECTION OF LESSEE'S SYSTEM

9.1 GENERAL. After the Effective Date, Lessee has the right but not the
obligation to request additional Buildings to be interconnected with the Lessee
Fiber.

9.2 SPLICE POINTS. Except as limited by Section 9.3, MFN will provide Lessee
with access to the MFN System backbone at mutually agreed upon
manholes/handholes ("Splice Point(s)") for the purpose of interconnecting a
Lessee-owned lateral connection to the Lessee Fiber. Upon acceptance of Lessee's
request for a Splice Point, MFN, in its reasonable discretion, will select the
closest serving manhole or handhole. Lessee must provide and install
Lessee-owned manholes/handholes and/or conduit to the selected MFN
manhole/handhole for Splice Point interconnection. MFN or an MFN-approved
contractor will perform all interconnection work,

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including penetration of the MFN manholes/handholes, installation of the
conduit, and pulling and maintaining the fiber optic cable between Lessee's
facilities and the selected MFN manhole/handhole. All work in MFN
manholes/handholes and splice enclosures, including splicing and
manhole/handhole penetration, will be managed and supervised by MFN. MFN will
then provide a ribbon tie cable between Lessee's facilities and MFN's selected
manhole/handhole, and each party will perform splicing in its own
manhole/handhole. MFN will invoice and Lessee agrees to pay all Costs associated
with MFN's provision of Splice Points, including the cost of the ribbon tie
cable. MFN shall allow Lessee to connect at agreed upon Splice Points at any
time during the Term at no cost to Lessee other than those provided hereinabove.

9.3 DATA CENTER ACCESS. MFN Data Center Access is restricted to Lessee's
provision of dedicated private line transport services to Lessee's customers.
Under no circumstances is Lessee permitted to sell IP transit services or
dedicated dark fiber transactions that originate or terminate in an MFN Data
Center, unless permitted pursuant to a separate agreement with MFN. MFN reserves
the right to inspect Lessee's use of a MFN Data Center at any time, 24 hours per
day, after reasonable notice to Lessee. Any violation of this section is deemed
a material breach of the Agreement. Nothing herein shall restrict Lessee from
providing any and all services to Lessee customers in separate space located
outside or within the same building as the MFN Data Center.

Collocation within a MFN Data Center facility is pursuant to separate
collocation license agreement executed between the Parties.

9.4 DEMARCATION POINT.

         (a) BUILDINGS. The Demarcation Point for a Building shall be at:

                  (i) MFN's fiber patch panel, the DSX-N panel (as designated by
         MFN), a splice enclosure in the basement or MFN closest serving manhole
         serving the Building; provided, however, that MFN agrees to provide
         conduit connectivity to Lessee at all non-ILEC Buildings; or

                  (ii) the demarcation point mandated by the agreement between
         Lessor and the ILEC; and, to the extent Lessor is later allowed to
         install or access a fiber patch panel or DSX-N panel inside of the
         Building, such point shall become the Demarcation Point if mutually
         agreeable and Lessor agrees to deliver Lessee's Fiber to such point.

(b) SPLICE POINTS. The Demarcation Point for each Splice Point is at the
Lessee-provided manhole/handhole unless otherwise agreed upon by the parties.

9.5 ADDITIONAL LIMITATIONS ON INTERCONNECTION RIGHTS. Lessee's exercise of the
interconnection right set forth in Section 9.2 shall be subject to any
prohibitions or restrictions in

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MFN's Right-of-Way Authorizations. Lessee may not establish an interconnection
that MFN, in its reasonable discretion (applied without unreasonable
discrimination with respect to interconnections made by MFN or third parties),
determines is likely to materially and adversely affect the MFN System.

9.6 FACILITIES OWNERSHIP AND CONTROL. Lessee shall retain ownership of any
portion of facilities on its side of the Demarcation Point during the Term of
this Agreement and MFN shall have no obligation to maintain, repair, relocate,
or monitor such Lessee facilities (including any fiber drop facilities
established pursuant to Section 9.3). Lessee shall not access a splice, splice
box, splice vault, or similar facility interconnecting with MFN's System. MFN
shall perform any work required with respect to such splice facilities and may
invoice Lessee for the Cost of performing such work at the request of Lessee
(except to the extent the work relates to the termination in a Building).

9.7 LESSEE RESPONSIBILITY. Subject to the provisions herein, Lessee shall be
responsible for obtaining the rights required and for all costs of:

         (a) obtaining rights of way within or beyond MFN's Right-of-Way
         Authorizations;

         (b) obtaining building access, entry rights, ducts, or riser cables to
         interconnect in buildings or any access beyond MFN's Demarcation Point
         with respect to a Building;

         (c) providing all Equipment and MFN-approved materials to construct and
         install each interconnection, including cables and conduit and any
         labor charges associated therewith; and

         (d) bringing facilities to and connecting them with MFN's System.

9.8 THIRD PARTY RELATIONS. If necessary, and where applicable, MFN shall assist
Lessee, at Lessee's Cost, in obtaining from any land or building owner, MFN, or
private or governmental right-of-way owner, any rights required to access and
exit interconnection points. Lessee shall use reasonable efforts to avoid
damaging the relationships between MFN and such third parties.

ARTICLE 10.  USE OF THE LESSEE FIBER

10.1 OBLIGATION TO COMPLY WITH LAWS; EXCLUSIVE USE. Lessee shall comply in all
material respects with all applicable government codes, ordinances, laws, rules,
regulations, Right-of-Way Authorizations and/or restrictions in its use of MFN's
System. Subject to Article 20, Lessee may use the Lessee Fiber for any lawful
telecommunications purpose. MFN shall have no right to use Lessee Fiber during
the Term of this Agreement.

10.2 SYSTEM DAMAGE. MFN and Lessee shall promptly notify each other of any
matters pertaining to any damage or impending damage to or loss of the MFN
System that are known to

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such party. Lessee shall take all commercially reasonable precautions against,
and shall assume liability, subject to the terms herein, for, any damage caused
by it to the MFN System. Lessee shall not use the Lessee Fiber in a way that
interferes in any material way with or materially adversely affects the use of
any fibers of MFN or the MFN System.

10.3 REGULATORY COOPERATION. Each party shall cooperate with and support the
other in complying with any requirements applicable to the MFN System imposed by
any governmental or regulatory agency or authority.

10.4 LIENS. Lessee shall not cause or permit any part of the MFN System to
become subject to any mechanics lien, materialmans lien, vendors lien, or any
similar lien whether by operation of law or otherwise. If Lessee breaches its
obligations under this Section, it shall immediately notify MFN in writing,
shall promptly cause such lien to be discharged and released of record without
cost to MFN, and shall indemnify MFN against all costs and expenses (including
reasonable attorney's fees and court costs at trial and on appeal) incurred in
discharging and releasing such lien.

ARTICLE 11. PAYMENT TERMS

11.1 TIME AND METHOD OF PAYMENT. Monthly payments for Lease Fiber and Buildings
shall be made by wire transfer, to the account designated on the invoice of MFN,
within thirty (30) days of the delivery of such invoice. Except as otherwise set
forth in this Agreement, all other amounts due hereunder shall be paid within 30
calendar days of the invoice delivery date. Except as otherwise provided,
payments may be made by check or draft of immediately available funds delivered
to the address designated in writing by the other party (e.g., in a statement or
invoice) or, failing such designation, to the address for notice provided
pursuant to Section 15.1. Except as set forth herein, a party may issue an
invoice after incurring any costs subject to reimbursement by the other party or
after the time period during which a charge accrues.

11.2 LATE PAYMENT CHARGES. If Lessee fails to make any payment under this
Agreement when due, such unpaid amounts shall accrue interest, from the date
such payment is due until paid, including accrued interest, at the lower of
eighteen percent (18%) annual interest or the highest percentage allowed by law.

11.3 MONTHLY NETTING AGREEMENT. Notwithstanding anything to the contrary
contained herein, that certain Monthly Netting Agreement between the parties
dated October 30, 2001 shall govern payments made under this Agreement for the
term of such Monthly Netting Agreement.

ARTICLE 12. INDEMNIFICATION

12.1 INDEMNITY OBLIGATION. Each party shall indemnify, defend, protect and hold
harmless the other party, its employees, officers, directors, agents,
shareholders, affiliates, Facility

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Owners/Lenders, and other parties to Right-of-Way Authorizations that are
entitled to indemnity by such indemnifying party, from and against, and assumes
liability for:

(a) Any injury, loss or damage to any person, tangible property or facilities of
any person or entity (including reasonable attorney's fees and costs), to the
extent arising out of or resulting from the acts or omissions, negligent or
otherwise, of the indemnifying party, its officers, employees, servants,
affiliates, agents or contractors in connection with its performance under this
Agreement; and

(b) Any claims, liabilities or damages arising out of any violation by the
indemnifying party of regulations, rules, statutes or court orders of any local,
state or federal governmental agency, court or body in connection with its
performance under this Agreement.

12.2 NO LIMITATION ON CLAIMS AGAINST OTHER PARTIES. Except as set forth herein,
and subject to the terms of any underlying agreements between MFN and any third
person, nothing contained herein shall operate as a limitation on the right of
either party hereto to bring an action for damages against any third person,
including indirect, special or consequential damages, based on any acts or
omissions of such third person as such acts or omissions may affect the
construction, operation or use of the Lessee Fiber; provided, however, that each
party hereto shall assign such rights of claims, execute such documents and do
whatever else may be reasonably necessary to enable the other party to pursue
any such action against such third person.

ARTICLE 13. INSURANCE

13.1 OBLIGATION TO OBTAIN. During the Term of this Agreement, the parties shall
each obtain and maintain not less than the following insurance:

(a) Commercial General Liability Insurance, including coverage for sudden and
accidental pollution legal liability, with a combined single limit of
$10,000,000 for bodily injury and property damage per occurrence and in the
aggregate; provided that such coverage may be obtained through a combination of
specific and umbrella or excess liability policies.

(b) Worker's Compensation Insurance in amounts required by applicable law and
Employers Liability Insurance with limits not less than $1,000,000 each
accident. If a party is to perform work in Nevada, North Dakota, Ohio,
Washington, Wyoming, or West Virginia, the party shall participate in the
appropriate state fund(s) to cover all eligible employees and provide a stop gap
endorsement.

(c) Automobile Liability Insurance with a combined single limit of $2,000,000
for bodily injury and property damage per occurrence, to include coverage for
all owned, non-owned, and hired vehicles; provided that such coverage may be
obtained through a combination of specific and umbrella or excess liability
policies.

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The limits set forth above are minimum limits and shall not be construed to
limit the liability of either party.

13.2 POLICY REQUIREMENTS. Each party shall obtain and maintain the insurance
policies required above with companies rated A- or better by Best's Key Rating
Guide or with a similar rating by another generally recognized rating agency.
The other party, its Affiliates, officers, directors, and employees, and any
other party entitled to indemnification hereunder shall be named as additional
insureds to the extent of such indemnification. Each party shall provide the
other party with an insurance certificate confirming compliance with the
insurance requirements of this Article. The insurance certificate shall indicate
that the other party shall be notified not less than 30 calendar days prior to
any cancellation or material change in coverage. If either party provides any of
the foregoing coverages through a claims made policy basis, that party shall
cause such policy or policies to be maintained for at least three years beyond
the expiration of this Agreement.

13.3 WAIVER OF SUBROGATION. The parties shall each obtain from the insurance
companies providing the coverages required by this Agreement a waiver of all
rights of subrogation or recovery in favor of the other party and, as
applicable, its members, managers, shareholders, Affiliates, assignees,
officers, directors, and employees or any other party entitled to indemnity
under this Agreement to the extent of such indemnity.

13.4 BLANKET POLICIES; SELF-INSURANCE. Nothing in this Agreement shall be
construed to prevent either party from satisfying its insurance obligations
pursuant to this Agreement (a) under a blanket policy or policies of insurance
that meet or exceed the requirements of this Article or (b) with respect to the
insurance required in Sections 13.1(b) and (c), with the consent of the other
party, which consent shall not be unreasonably withheld, self-insurance.

ARTICLE 14. TAXES AND FRANCHISE, LICENSE AND PERMIT FEES

14.1 OBLIGATIONS TO PAY RIGHT-OF-WAY CHARGES AND TAXES. The parties acknowledge
that a material premise of this Agreement is that during the Term, MFN shall
obtain, and use commercially reasonable efforts to maintain, its Right-of-Way
Authorizations at its own cost. MFN shall timely pay any and all (a) taxes,
franchise, license and permit fees based on the physical location of the MFN
System, and/or the construction thereof in or on public roads, highways or
rights-of-way; and (b) Right-of-Way Authorization payments applicable to the
System. Notwithstanding the foregoing, Lessee shall pay any taxes, franchise,
license and permit fees based upon its Lease or use of Lessee Fiber. Failure to
pay such taxes or payments by the party responsible therefor, which continues
after seven (7) calendar days written notice thereof by the other party, shall
authorize, but not obligate, the other party to make such payments and
responsible party shall reimburse the other party for such payments promptly
upon demand together with interest at the rate set forth in Section 14.2 from
the date that the other party made such payment until reimbursed by the
responsible party.

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14.2 OBLIGATION TO TIMELY PAY TAXES BASED ON REVENUES. Except as set forth in
Section 14.1, Lessee shall pay any and all sales, use, income, gross receipts or
other taxes assessed based upon revenues Lessee receives due to its use of the
Lessee Fiber.

14.3 RIGHT TO CONTEST TAXES. Notwithstanding any provision herein to the
contrary, a party shall have the right by appropriate proceedings brought in
good faith to protest the imposition and/or amount of any taxes or franchise,
license or permit fees imposed on or assessed against it. In such event, the
protesting party shall indemnify and hold the other party harmless from any
expense, legal action or cost, including reasonable attorney's fees, resulting
from the protesting party's exercise of its rights hereunder.

14.4 PROHIBITION ON AGREEMENTS AFFECTING OTHER PARTY. Without the prior consent
of Lessee, MFN shall not enter into any agreement that would have the effect of
obligating Lessee to pay additional taxes or franchise, license or permit fees
unless such agreement is required by a government or agency thereof in
connection with the grant of a franchise, license, permit or similar
governmental requirement or required pursuant to a Right-of-Way Authorization.

ARTICLE 15. NOTICE

15.1 ADDRESSES. Unless otherwise provided herein, all notices and communications
concerning this Agreement shall be addressed to the other party as follows:

If to Lessee:                       Williams Communications, LLC
                                    Attn: Contract Management
                                    One Technology  Center, MD-6H
                                    Tulsa, Oklahoma 74103
                                    Facsimile:  (918) 547-0460

with a copy to:                     Williams Communications, LLC
                                    Attn:   Lease Administration
                                    One Technology Center, 8A
                                    Tulsa, OK 74103
                                    Facsimile:  (918) 547-2914

and                                 Williams Communications, LLC
                                    Attn: General Counsel
                                    One Technology Center, TC-15A
                                    Tulsa, Oklahoma 7415
                                    Facsimile:  (918) 547-2630

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If to MFN:                          Metromedia Fiber Network Services, Inc.
                                    360 Hamilton Avenue
                                    White Plains, New York 10601
                                    Attn:  President
                                    Facsimile:  (914) 421-7550

With a copy to:                     Metromedia Fiber Network Services, Inc.
                                    360 Hamilton Avenue
                                    White Plains, New York 10601
                                    Attn:  General Counsel
                                    Facsimile:  (914) 421-6793

or at such other address as may be designated in writing to the other party (a
party may designate a separate address for delivery of invoices).

15.2 METHOD FOR DELIVERING NOTICES AND INVOICES. Unless otherwise provided
herein, notices and invoices shall be in writing and sent by registered or
certified U.S. Mail, postage prepaid, or by commercial overnight delivery
service, or by facsimile, and shall be deemed served or delivered to the
addressee or its office on the date of receipt acknowledgment, or if by
facsimile, upon confirmation of transmission or if postal claim notices are
given, on the date of its return marked "unclaimed," provided, however, that
upon receipt of a returned notice marked "unclaimed," the sending party shall
make reasonable effort to contact and notify the other party by telephone.

ARTICLE 16. CONFIDENTIALITY AND PUBLICITY

16.1 CONFIDENTIAL INFORMATION. The terms and conditions of this Agreement and
all documents referenced herein, communications between the parties regarding
this Agreement, information provided in connection with or pursuant to this
Agreement or the service to be provided hereunder, as well as any financial or
business information of either party are confidential ("Confidential
Information"). Such Confidential Information shall be held in confidence, and
the receiving party shall afford such Confidential Information the same care and
protection as it affords generally to its own Confidential Information (which in
any case shall be not less than reasonable care) to avoid disclosure to or
unauthorized use by any third party. All Confidential Information shall remain
the property of the disclosing party, shall be used by the receiving party only
for its intended purpose, and such Confidential Information, including all
copies thereof, shall be returned to the disclosing party or destroyed after the
receiving party's need for it has expired or upon the request of the disclosing
party. Confidential Information shall not be reproduced except to the extent
necessary to accomplish the purposes and intent of this Agreement, or as
otherwise may be permitted in writing by the disclosing party. Notwithstanding
anything contained herein to the contrary, neither party shall be required to
keep confidential any information that (a) becomes publicly available other than
through the actions or omissions of the

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receiving party; (b) is required to be disclosed pursuant to a governmental or
judicial rule, order or regulation; (c) the recipient of the Confidential
Information independently develops; (d) becomes available to the receiving party
without restriction from a third party; (e) is required by its lender and is
given to such lender on a confidential basis; or (f) is subject to "due
diligence" review by a potential acquirer of a significant equity interest in it
or its ultimate or intermediate parent company (a significant equity interest
shall be an interest of at least 5% of the voting equity of a party or of
securities having a market value of at least $100 million) and is given to such
potential acquirer on a confidential basis.

16.2 PUBLICITY. Following the Effective Date, the parties shall coordinate and
cooperate with each other when making public announcements or disclosures to any
governmental entities related to the terms of this Agreement and each party
shall have the right to promptly review, comment upon and approve (such approval
not to be unreasonably withheld or delayed) any publicity materials, press
releases or other public statements or disclosures to governmental entities by
the other party that refer to, or that describe any aspect of this Agreement;
provided, however, that no party shall have an approval right with respect to
any public announcements or disclosures to any governmental entities which are,
in the reasonable judgment of the party making such public announcement or
disclosure, required by law.

ARTICLE 17. DEFAULT

17.1 PARTIAL TERMINATION UPON DEFAULT. Either party, upon written notice to the
other party after the other party's default and the other party's failure to
cure any default in the performance of any material obligation hereunder prior
to the end of the applicable cure period, may terminate this Agreement as herein
provided, provided that at the time of termination such default remains uncured:

         (a) MFN may terminate this Agreement, to the extent that Lessee is the
defaulting party; and/or

         (b) Lessee may terminate this Agreement, to the extent that the default
relates to the MFN System (or, at Lessee's election, with respect to any Lessee
Fiber for which the Acceptance Date has not occurred as provided in Article 5),
if MFN is the defaulting party.

17.2 SPECIFIC DEFAULT EVENTS. Events of default shall include but not be limited
to: (a) the making of a general assignment for the benefit of the defaulting
party's creditors; (b) the filing of a voluntary petition in bankruptcy or the
filing of a petition in bankruptcy or other insolvency protection against the
defaulting party which is not dismissed within 90 calendar days thereafter; (c)
the filing by the defaulting party of any petition or answer seeking, consenting
to, or acquiescing in reorganization, arrangement, adjustment, composition,
liquidation, dissolution, or similar relief; (d) any violation by Lessee of the
restrictions set forth in Section 20.3.

17.3 CURE PERIOD. The cure period applicable to Section 17.1 shall be:

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         (a) with respect to a default in payment, the period ending ten (10)
business days after a written notice of such default is given;

         (b) with respect to any other default, the period ending 30 calendar
days after a written notice of such default is given, provided, however, that if
such default cannot with reasonable diligence be cured within such 30-day
period, and such other party has commenced to effect a cure immediately upon
receipt of such notice, and diligently pursues such cure, then such cure period
will be extended for a period reasonably required to cure such default but in no
event more than an additional 30 calendar days.

17.4 FAILURE TO CURE. Upon the failure by the defaulting party to timely cure
any such default after notice thereof from the other party, the other party may,
subject to the provisions of Section 19, take such action as it determines, in
its sole discretion, to be necessary to correct the default, and pursue any
legal remedies it may have under this Agreement, applicable law, or principles
of equity relating to such breach.

17.5 WAIVER OF SPECIFIC DEFAULTS. Any event of default by the defaulting party
may be waived under the terms of this Agreement at the other party's option. Any
such waiver shall be in writing.

17.6 DISPUTED AMOUNTS. Notwithstanding the other provisions of this Article,
failure to pay an amount subject to a bona fide dispute shall not be an event of
default (until such dispute is resolved pursuant to Article 19 or otherwise) to
the extent the disputed amount is (a) less than $100,000 or (b) paid into an
escrow account of a nationally chartered domestic bank with offices in New York
pending resolution of the dispute. The interest rate set forth in Section 11.2
shall apply to amounts so withheld or paid into escrow by one party and later
awarded to the other party, but the party paying such amounts into escrow shall,
upon closing of an escrow account, be entitled to any interest received from,
and responsible for paying any fees charged by, the bank holding the escrow
funds.

ARTICLE 18. FORCE MAJEURE

Neither party shall be in default under this Agreement with respect to any delay
in such party's performance (other than the payment of monetary amounts due
under this Agreement) caused by any of the following conditions: act of God,
fire, flood, material shortage or unavailability not resulting from the
responsible party's failure to timely place orders therefor, lack of
transportation, government codes, ordinances, laws, rules, regulations or
restrictions, war or civil disorder, or any other cause beyond the reasonable
control of such party, provided that the party claiming relief under this
Section shall promptly notify the other in writing of the existence of the event
relied on and the cessation or termination of said event. The party claiming
relief under this Section shall exercise commercially reasonable efforts to
minimize the time for any such delay.

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ARTICLE 19. ARBITRATION

19.1 OBLIGATION TO ARBITRATE. Any dispute or disagreement relating to this
Agreement or any matter arising between Lessee and MFN in connection with this
Agreement which is not settled to the mutual satisfaction of Lessee and MFN
within 30 calendar days from the date that either party informs the other in
writing that such dispute or disagreement exists, shall be settled by
arbitration by a single arbitrator in Chicago, Illinois, in accordance with the
Commercial Arbitration Rules of the American Arbitration Association in effect
on the date that such notice is given. If the parties are unable to agree on a
single arbitrator within fifteen calendar days, the American Arbitration
Association shall select an arbitrator. The decision of the arbitrator shall be
final and binding upon the parties and shall include written findings of law and
fact, and judgment may be obtained thereon by either party in a court of
competent jurisdiction. Each party shall bear the cost of preparing and
presenting its own case. The cost of the arbitration, including the fees and
expenses of the arbitrator, shall be shared equally by the parties unless the
award otherwise provides.

19.2 EXCEPTIONS TO ARBITRATION OBLIGATION. The obligation herein to arbitrate
shall not be binding upon any party with respect to requests for preliminary
injunctions, temporary restraining orders or other procedures in a court of
competent jurisdiction to obtain interim relief when deemed necessary by such
court to preserve the status quo or prevent irreparable injury pending
resolution by arbitration of the actual dispute.

ARTICLE 20. ASSIGNMENT

20.1 RESTRICTIONS ON ASSIGNMENT. Except as provided in the second sentence of
this Section, neither party shall assign or otherwise transfer this Agreement or
its rights or obligations hereunder to any other party without the prior written
consent of the other party, which consent shall not be unreasonably withheld or
delayed. Either party shall have the right, without the other party's consent,
to assign or otherwise transfer this Agreement in whole or in part as collateral
to any lender or to any of its Affiliates or to any corporation into which it
may be merged or consolidated or which purchases all or substantially all of its
assets.

20.2 AGREEMENT BINDS SUCCESSORS. This Agreement and each of the party's
respective rights and obligations under this Agreement, shall be binding upon
and shall inure to the benefit of the parties hereto and each of their
respective successors and permitted assigns. Any assignment or transfer shall be
subject to the other party's rights under this Agreement and any assignee or
transferee shall continue to perform the assigning party's obligations under
this Agreement.

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20.3 RESTRICTION ON TRANSFER OF DARK FIBER RIGHTS.

         (a) MFN is providing the Lessee Fiber for Lessee's exclusive use.
Lessee may not sublease, swap, assign, license, sublicense, sell or share the
Lessee Fiber as "dark fiber", as such term is commonly understood in the
telecommunications industry.

         (b)[******************************************************************
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20.4 FINANCING ARRANGEMENTS. Either party shall have the right, directly or
through an Affiliate, to enter into financing arrangements (including secured
loans, leases, sales with lease-back, or leases with lease-back arrangements,
purchase-money or vendor financing, conditional sales transactions, or other
arrangements) with one or more financial institutions, vendors, suppliers or
other financing sources that, with respect to MFN, relate to the MFN System and,
with respect to Lessee, relate to Lessee's Lease rights (and not to any property
right in the MFN System or the Lessee Fiber).

ARTICLE 21. RULES OF CONSTRUCTION

21.1 GOVERNING LAW. This Agreement shall be deemed a New York agreement and
shall be governed by and construed in accordance with the domestic laws of the
State of New York applicable to New York agreements, without reference to its
choice of law principles.

21.2 INTERPRETATION. The captions or headings in this Agreement are strictly for
convenience and shall not be considered in interpreting this Agreement or as
amplifying or limiting any of its content. Words in this Agreement that import
the singular connotation shall be interpreted as plural, and words that import
the plural connotation shall be interpreted as singular, as the identity of the
parties or objects referred to may require. References to "person" or "entity"
each include natural persons and legal entities, including corporations, limited
liability companies, partnerships, sole proprietorships, business divisions,
unincorporated associations, governmental entities, and any entities entitled to
bring an action in, or that are subject to suit in an action before, any state
or federal court of the United States. Whenever the words "include," "includes"
or "including" are used in this Agreement, they shall be deemed to be followed
by the words "without limitation." "Days" refers to calendar days, except that
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Saturdays, Sundays and holidays during which nationally chartered banks in New
York, New York are authorized or required to close. Unless expressly defined
herein, words having well-known technical or trade meanings shall be so
construed.

21.3 CUMULATIVE REMEDIES. Except as set forth to the contrary herein, any right
or remedy of either party shall be cumulative and without prejudice to any other
right or remedy, whether contained herein or not.

21.4 NO THIRD-PARTY RIGHTS. Nothing in this Agreement is intended to provide any
legal rights to anyone not an executing party of this Agreement except under the
indemnification and insurance provisions and except (a) as set forth in Sections
22.4 and 23.2 and (b) that the Facility Owners/Lenders shall be entitled to rely
on and have the benefit of Article 23.

21.5 AGREEMENT FULLY NEGOTIATED. This Agreement has been fully negotiated
between and jointly drafted by the parties.

21.6 DOCUMENT PRECEDENCE. In the event of a conflict between the provisions of
this Agreement and those of any Exhibit, the provisions of this Agreement shall
prevail and such Exhibits shall be corrected accordingly. In the event of a
conflict between the provisions of this Agreement and Product Order, the
provisions of the Product Order prevail.

21.7 INDUSTRY STANDARDS. Except as otherwise set forth herein, for the purpose
of this Agreement the normal standards of performance within the
telecommunications industry in the relevant market shall be the measure of
whether a party's performance is reasonable and timely.

21.8 CROSS REFERENCES. Except as the context otherwise indicates, all references
to Exhibits, Parts, Schedules, Articles, Sections, Subsections, Clauses, and
Paragraphs refer to provisions of this Agreement.

21.9 LIMITED EFFECT OF WAIVER. The failure of either MFN or Lessee to enforce
any of the provisions of this Agreement, or the waiver thereof in any instance,
shall not be construed as a general waiver or relinquishment on its part of any
such provision, but the same shall nevertheless be and remain in full force and
effect.

21.10 SEVERABILITY. If any term, covenant or condition in this Agreement shall,
to any extent, be invalid or unenforceable in any respect under the laws
governing this Agreement, the remainder of this Agreement shall not be affected
thereby, and each term, covenant or condition of this Agreement shall be valid
and enforceable to the fullest extent permitted by law.

21.11 NO PARTNERSHIP CREATED. The relationship between MFN and Lessee shall not
be that of partners, agents, or joint venturers for one another, and nothing
contained in this Agreement shall be deemed to constitute a partnership or
agency agreement between them for any purposes, including federal income tax
purposes. The parties, in performing any of their obligations

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hereunder, shall be independent contractors or independent parties and shall
discharge their contractual obligations at their own risk.

21.12 NO REIMBURSEMENT. Unless provided otherwise herein, each party shall
perform its obligations without right of reimbursement or contribution from the
other party.

21.13 RIGHT TO SUBCONTRACT. MFN or the underlying facility owner may subcontract
for any of its obligations hereunder, including splicing, testing, maintenance,
repair, relocation, and restoration services. MFN may fulfill its obligations to
provide Lessee Fiber in its System by constructing, acquiring title to,
acquiring rights in, leasing, entering into financing leases, or otherwise
obtaining a right to use its System or various portions thereof. The use of any
such subcontractor, underlying Lease provider, financing arrangement, or other
arrangement shall not relieve MFN of its obligations hereunder.

21.14 SURVIVAL. No termination or expiration of this Agreement, either in part
or in whole, shall affect the rights or obligations of any party hereto: (i)
with respect to any payment hereunder for services rendered prior to the date of
termination; (ii) pursuant to Articles 12, 13, 14, 16, 19, 21, 23, and 24
entitled Indemnification; Insurance; Taxes and Franchise, License, and Permit
Fees; Confidentiality and Publicity; Arbitration; Rules of Construction;
Limitation of Liability; and Audit Rights; respectively; or (iii) pursuant to
other provisions of this Agreement that, by their sense and context, are
intended to survive termination of this Agreement.

ARTICLE 22. REPRESENTATIONS AND WARRANTIES

22.1 AGREEMENT VALIDITY. Each party represents and warrants that:

(a) It has the full right and authority to enter into, execute, deliver and
perform its obligations under this Agreement;

(b) It has taken all requisite corporate action to approve the execution,
delivery and performance of this Agreement;

(c) This Agreement constitutes a legal, valid and binding obligation enforceable
against such party in accordance with its terms;

(d) Its execution of and performance under this Agreement shall not violate any
applicable existing regulations, rules, statutes or court orders of any local,
state or federal government agency, court or body; and

(e) It has the right pursuant to such party's Right-of-Way Authorizations to
grant the rights to the other party as set forth in this Agreement.

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22.2 ACCEPTANCE DATE REPRESENTATIONS. As of the Acceptance Date for any Lessee
Fiber, MFN represents that:

(a) MFN or the underlying facility owner for any portion of the Lessee Fiber
shall have obtained all Right-of-Way Authorizations necessary for the
installation and use of the Lessee Fiber hereunder;

(b) MFN shall have obtained by Lease agreement, lease, or otherwise the right to
use portions of the Lessee Fiber it does not own;

(c) MFN shall have obtained all Right-of-Way Authorizations for the Lessee
Fiber;

(d) no Right-of-Way Authorizations for such Lessee Fiber impose unreasonable
limitations or requirements on Lessee's exercise of its rights under this
Agreement; and

(e) the Lessee Fiber has been designed, engineered, installed, and constructed
in accordance with the specifications set forth in Exhibit F and in compliance
with all applicable building, construction and safety codes for such
construction and installation, as well as any and all other applicable
governmental laws, codes, ordinances, statutes and regulations.

22.3 DISCLAIMER OF WARRANTY. EXCEPT AS SPECIFICALLY SET FORTH IN THIS AGREEMENT,
MFN MAKES NO WARRANTY TO LESSEE OR ANY OTHER PERSON OR ENTITY, WHETHER EXPRESS,
IMPLIED, OR STATUTORY, AS TO THE DESCRIPTION, QUALITY, MERCHANTABILITY,
COMPLETENESS OR FITNESS FOR ANY PURPOSE OF ANY FIBERS OR ANY SERVICE PROVIDED
HEREUNDER OR DESCRIBED HEREIN, OR AS TO ANY OTHER MATTER, ALL OF WHICH
WARRANTIES ARE HEREBY EXCLUDED AND DISCLAIMED.

22.4 NO THIRD-PARTY WARRANTIES. NO FACILITY OWNERS/LENDERS HAVE MADE ANY
REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, TO LESSEE CONCERNING
MFN, LESSEE FIBERS, THE CABLE, OR THE SYSTEM OR AS TO ANY OF THE MATTERS SET
FORTH IN SECTIONS 22.1 OR 22.2. NO LESSEE LENDERS HAVE MADE ANY REPRESENTATION
OR WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, TO MFN CONCERNING LESSEE, LESSEE
FIBERS, THE CABLE, ANY LEASES OR THE MFN SYSTEM OR AS TO ANY OF THE MATTERS SET
FORTH IN SECTIONS 22.1 OR 22.2 OR AS TO ANY OTHER MATTER.

ARTICLE 23. LIMITATIONS OF LIABILITY

23.1 RESTRICTION ON TYPES OF LIABILITY. Notwithstanding any provision of this
Agreement to the contrary, in no event shall either party be liable to the other
party for any special, incidental, indirect, punitive, reliance or consequential
damages, whether foreseeable or not, arising out of, or in connection with this
Agreement, in tort, breach of contract, breach of warranty, strict

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liability or any other cause of action, including damage or loss of property or
equipment, loss of profits or revenue, cost of capital, cost of replacement
services, or claims of customers, whether occasioned by any repair or
maintenance performed by, or failed to be performed by, the first party or any
other cause whatsoever.

23.2 NO RECOURSE AGAINST RELEASED PARTIES. Neither party shall have any recourse
of any kind against any Released Party or any assets of a Released Party under
this Agreement, it being expressly agreed and understood that no liability
whatever shall attach to or be incurred by any Released Party under or by reason
of this Agreement or any other instrument, arrangement or understanding related
to Lessee Fiber. Each party waives all such recourse to the extent set forth in
this Section on behalf of its successors, assigns, and any entity claiming by,
through, or under such party.

23.3 NO PERSONAL LIABILITY. Each action or claim against any party arising under
or relating to this Agreement shall be made only against such party as a
corporation, and any liability relating thereto shall be enforceable only
against the corporate assets of such party. No party shall seek to pierce the
corporate veil or otherwise seek to impose any liability relating to, or arising
from, this Agreement against any shareholder, employee, officer, director or
agent of the other party. Each of such persons is an intended beneficiary of the
mutual promises set forth in this Section and shall be entitled to enforce the
obligations or provisions of this Section.

ARTICLE 24. AUDIT RIGHTS

            (a) Each party shall keep such books and records (which shall be
maintained on a consistent basis and substantially in accordance with generally
accepted accounting principles) as shall readily disclose the basis for any
charges (except charges fixed in advance by this Agreement or by separate
agreement of the parties) or credits, ordinary or extraordinary, billed or due
to the other party under this Agreement and shall make them available for
examination, audit, and reproduction by the other party and its agents for a
period of one year after such charge or credit is billed or due. To the extent a
party seeks reimbursement of out-of-pocket costs or services provided on a
per-hour basis, it shall provide reasonable supporting documentation to the
other party.

         (b) If requested by MFN, Lessee will provide MFN with copies of
documents supporting the disclosures made by Lessee under Section 20.3(b)
related to Unrestricted Fiber transactions.

ARTICLE 25. IMPROPER PAYMENTS PROHIBITED

Neither party shall use any funds received under this agreement for illegal or
otherwise "improper" purposes. Neither party shall pay any commission, fees or
rebates to any employee of the other party. If either party has reasonable cause
to believe that one of the provisions in this

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article has been violated, it, or its representative, may audit the books and
records of the other party for the sole purpose of establishing compliance with
such provisions.

ARTICLE 26. ENTIRE AGREEMENT; AMENDMENT; EXECUTION

26.1 INTEGRATION; INCORPORATION; MODIFICATION. This Agreement constitutes the
entire agreement and understanding between the parties with respect to the
subject matter hereof and supersedes all prior agreements whether written or
oral relating to the subject matter hereof, which are of no further force or
effect. The Exhibits and Schedules referred to herein are integral parts hereof
and are hereby made a part of this Agreement. This Agreement may be modified or
supplemented only by an instrument in writing executed by a duly authorized
representative of each party.

26.2 COUNTERPARTS; EXECUTION. This Agreement may be executed in one or more
counterparts, all of which taken together shall constitute one and the same
instrument. A party may duly execute and deliver this Agreement by execution and
facsimile delivery of the signature page of a counterpart to the other party,
provided that, if delivery is made by facsimile, the executing party shall
promptly deliver a complete counterpart that it has executed to the other party.

In confirmation of their consent to the terms and conditions contained in this
Agreement and intending to be legally bound hereby, the parties have executed
this Lease Agreement as of the date first above written.

METROMEDIA FIBER NETWORK SERVICES, INC., a Delaware corporation

Signature: /s/ WILLIAM G. LA PERCH
          -------------------------------------------

(Print) Name:  William G. La Perch
              ---------------------------------------

(Print) Title:  President
              ---------------------------------------

WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability company

Signature: /s/ HOWARD E. JANZEN
          -------------------------------------------

(Print) Name:  Howard E. Janzen
              ---------------------------------------

(Print) Title: President & CEO
              ---------------------------------------

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                                    EXHIBIT A

                          FIBER TESTING SPECIFICATIONS

MFN will perform fiber testing, as described below, on each Leased Fiber and
will provide documentation of these test results to the Customer via e-mail.
Each "span" will be defined in documentation included in the Customer's package.
Acceptance of a span by Customer will be an acknowledgement by the Customer that
all Leased Fiber complies with all performance criteria contained herein and
performs within the parameters of the fiber manufacturer's specifications.

1)       POWER TESTING: This end-to-end loss measurement will be conducted for
         each Leased Fiber in the span and from both directions using an
         industry-accepted laser source and power meter. The bi-directional
         average will be used to determine the end-to-end loss of the span at
         each appropriate wavelength. This test will be conducted at both 1310
         nm and 1550 nm for Standard Single Mode Fiber; Dispersion Shifted Fiber
         (True WaveTM, LEAFTM, etc.) will be tested at 1550 nm only. In the
         event that a span consists of both Standard Single Mode and Dispersion
         Shifted fiber types, only 1550 nm testing will be conducted. This power
         testing will ensure fiber continuity and the absence of crossed fibers
         in the span. Power testing will only be conducted where the Leased
         Fiber is terminated by MFN in fiber distribution panels at both ends of
         the span.

2)       OTDR TESTING: This testing will be conducted at both 1310 nm and 1550
         nm wavelengths when the Leased Fiber consists of Standard Single Mode
         Fiber, but will be done at 1550 nm only if the Leased Fiber consists of
         either Dispersion Shifted Fiber (True-WaveTM, LEAFTM, etc.) or a
         combination of Single Mode and Dispersion Shifted fiber types.

         OTDR testing will be conducted on a bi-directional basis for each
         Leased Fiber in each span at the appropriate wavelengths for the Leased
         Fiber described above. However, if due to length or attenuation reasons
         that the Leased Fiber span exceeds the dynamic range of an OTDR, a
         portion or the entire span may be tested on a unidirectional basis
         only. Alternatively, the Leased Fiber span may be divided into shorter
         testing spans, to the extent reasonably possible, in order to obtain
         bi-directional analysis. Also, in instances where a Customer intends to
         accept Leased Fiber that is not terminated at one end by MFN in a fiber
         distribution panel (such as in a manhole or handhole) only
         unidirectional testing will be performed.

         The turnover documentation package delivered to Customer will contain
         the actual traces that detail the testing parameters (including pulse
         width, averaging and range). The average bi-directional splice loss for
         all splices within each span will be of 0.15 dB or less while each
         connector pair (such as at a FDP) will have an average bi-directional
         loss of 0.5 dB or less. (Note that the front and end connector of the
         span can only be measured uni-directionally and will also have a loss
         equal to or less than 0.5 dB). In the event that OTDR acceptance
         testing must be done on a unidirectional basis (for reasons described
         above), an average per span splice loss will be 0.30 dB.

         If the average bi-directional splice loss of each span exceeds 0.15 dB
         (or 0.30 dB uni-directionally), MFN will provide upon the Customer's
         request documentation of at a least three attempts to reduce this value
         to below 0.15 dB (0.30 dB uni-directionally). The only exception to
         this will be in the instance of a splice between two different fiber
         types (Standard Single-mode to Dispersion Shifted, Depressed-Clad to
         Matched Clad, fibers with different mode-field diameters).

Customer should also note that the loss and/or reflectance of the front-end
connector (as measured using a launch cord) is only an indicator of a problem
such as a defective port, bulkhead, or the like. Since a different patch cord
will be used by Customer (that connects to their equipment, for example) to mate
to this connector, a different loss and/or reflectance may occur.

Exhibit A - Page 1
<PAGE>
EXECUTION COPY                                                     CONFIDENTIAL

                                   EXHIBIT B

                                  LESSEE FIBER

<Table>
<Caption>
                                                                                               LENGTH OF        NUMBER      FIBER
         CITY                                    FACILITY               ACCEPTANCE DATE       RING/SEGMENT    OF FIBERS     MILES
---------------------------      -------------------------------------  ---------------       ------------    ---------   --------
<S>                              <C>                                    <C>                   <C>             <C>         <C>
Atlanta                          56 Marietta (Atlanta 2A)                      2/12/2001             2.450            4      9.80
Atlanta                          DT Ring 1                                     7/17/2001             7.700           36    277.20
Atlanta                          56 Marietta - 874 DeKalb                     11/12/2001             2.450           32     78.40

Boston                           DT Ring 1                                     2/24/2000             7.993           36    287.73
Boston                           DT Ring 2                                     7/28/2000             8.361           18    150.50
Boston                           DT Ring 3                                     5/16/2000             5.820           36    209.52
Boston                           Sub-Ring 2 (Boston to Spring Street)          7/11/2001            16.000            4     64.00
Boston                           Sub-Ring 2                                    1/21/2002            35.250           32   1128.00

Central New Jersey               Ring 1                                        7/11/2000            81.000            6    486.00
Central New Jersey               Ring 2                                        3/13/2000            17.350            0      0.00

Chicago                          DT Ring 1                                      2/8/2000             3.420           24     82.08
Chicago                          DT Ring 2                                     3/10/2000             1.699           24     40.77
Chicago                          DT Ring 3                                     3/10/2000             2.363           24     56.70
Chicago                          DT Ring 4                                      2/8/2000             3.825           24     91.80
Chicago                          DT Ring 5                                     3/10/2000             3.394           24     81.45
Chicago                          DT Ring 6                                      2/8/2000            14.775           24    354.60
Chicago                          Ring 5 (Sub-Ring 5)                           2/28/2000            14.382            6     86.29
Chicago                          Ring 7 (DT Ring 7)                            7/11/2001             5.500           12     66.00
Chicago                          Sub-Ring 2                                    9/15/2000            86.499           16   1383.98
Chicago                          Sub-Ring 3                                     4/4/2001            74.000           10    740.00
Chicago                          Sub-Ring 4                                    7/14/2000            41.877           10    418.77
Chicago                          Sub-Ring 5 (Additional)                       12/6/2001            14.380           18    258.84

Dallas                           Ring 1                                         2/7/2000            30.573           36   1100.61
Dallas                           Ring 2                                        2/14/2000            66.769           36   2403.67
Dallas                           Ring 3                                        2/28/2000            41.365           18    744.57
Dallas                           Ring 4                                        5/16/2000            71.899           10    718.99

Denver                           CBD                                           6/21/2001             6.210           48    298.08

Houston                          Ring 1 (DT 1)                                 7/14/2000             7.380           24    177.12
Houston                          Ring 2 (DT 2)                                 7/14/2000             4.005           18     72.09
Houston                          Ring 3                                        7/14/2000            60.525           24   1452.60
Houston                          Ring 4                                        7/14/2000            55.970           18   1007.46
Houston                          Ring 5                                        7/14/2000            48.060           12    576.72
Houston                          Ring 5A                                       8/15/2000            12.503           12    150.03
Houston                          Ring 6                                        7/14/2000            11.149           16    178.38
Houston                          Ring 7                                        10/1/2001            63.150            8    505.20

Long Island                      Ring South (Ring 1)                           8/17/2000            62.406           20   1248.12

Los Angeles                      DT Ring 1                                     5/14/2001             1.340           24     32.16
Los Angeles                      DT Ring 2                                     5/17/2001             2.660           24     63.84
Los Angeles                      DT Ring 3                                     5/24/2001             3.700           24     88.80
Los Angeles                      DT Ring 4                                    10/17/2001             5.720           24    137.28
Los Angeles                      DT Ring 5                                      8/7/2001             1.035           60     62.10
Los Angeles                      Sub-Ring 1 (Lemon point-to-point)             1/28/2002             8.510            2     17.02
</Table>

Exhibit B - Page 1
<PAGE>
EXECUTION COPY                                                     CONFIDENTIAL

                                   EXHIBIT B

<Table>
<Caption>
                                                        INCOMPLETE SEGMENTS
-----------------------------------------------------------------------------------------------------------------------------------
                 SELECTED SEGMENT (BRANCH A)
-------------------------------------------------------                             LENGTH OF       NUMBER     ESTIMATED      TOTAL
        CITY                          FACILITY             DELIVERY DATE          RING/SEGMENT    OF FIBERS     MILES       CHARGES
------------------      -------------------------------    --------------         ------------    ---------   ---------     -------
<S>                     <C>                                <C>                    <C>             <C>         <C>           <C>
Manhattan               Ring 3                                   2/4/2000                5.864           60      351.81      $ [***]
Manhattan               Ring 4                                  3/13/2000                3.995           60      239.67      $ [***]
Manhattan               Ring 5                                  1/28/2000                3.389           60      203.31      $ [***]
Manhattan               Ring 6-1                                 2/1/2000               12.761           48      612.54      $ [***]
Manhattan               Ring 6-2                                9/16/2000               11.745           12      140.94      $ [***]
Manhattan               Ring 7                                   2/4/2000                8.025            6       48.15      $ [***]

New Jersey              Ring 1                                  6/13/2000               113.400          15     1701.00      $ [***]

New York City           Ring 2 (Manhattan 2) consol.                                    complex          57      272.85      $ [***]

Newark - 60 Hudson      Revised & Consolidated Billing          1/28/2000               complex     complex     1026.14      $ [***]

NY - Boston*            Span                                    2/23/2000               278.880           2      557.76      $ [***]

Philadelphia            DT Ring 1                               2/23/2000                 4.125          24       99.00      $ [***]
Philadelphia            DT Ring 2                               3/27/2000                 5.438          24      130.50      $ [***]
Philadelphia            DT Ring 3                               3/27/2000                 5.753          24      138.06      $ [***]
Philadelphia            Ring 4                                  6/11/2001                 4.170          12       50.04      $ [***]
Philadelphia            KP Loop                                 3/27/2000                 9.960           6       59.76      $ [***]
Philadelphia            Main Ring                               3/27/2000                56.466          10      564.66      $ [***]

Phoenix                 CBD                                     7/17/2001                 9.000          36     324.000      $ [***]

San Francisco           DT Ring 1                               6/15/2000                 7.200          36      259.20      $ [***]
San Francisco           DT Ring 2                               6/15/2000                 5.900          36      212.40      $ [***]
San Francisco           DT Ring 3                               6/13/2000                 3.560          36      128.16      $ [***]
San Francisco           DT Ring 4                               6/18/2000                 2.800          36      100.80      $ [***]
San Francisco           Oakland Ring (Ring 4)                   2/11/2002                 2.382          36       85.75      $ [***]
San Francisco           Sub Ring 1                              1/30/2001                 5.763           8       46.10      $ [***]

Santa Clara             50 West Fernando                        5/11/2001                 0.340           4        1.36      $ [***]

Seattle                 DT Ring 1                               8/15/2001                 4.415          36      158.94      $ [***]
Seattle                 DT Ring 2                                9/6/2001                 9.250          36      333.00      $ [***]
Seattle                 DT Ring 3                               8/15/2001                 4.490          32      143.68      $ [***]
Seattle                 DT Ring 3/4                            11/15/2001                 7.600           2       15.20      $ [***]
Seattle                 DT Ring 4 (1505 5th - 2001 6th)          3/5/2001                 4.260           3       12.78      $ [***]
Seattle                 Lake Washington Ring                     1/4/2002                79.080           2      158.16      $ [***]
Seattle                 Lake Washington Ring                    3/14/2002    16x76.01 + 18x0.54       16/18     1225.93      $ [***]
Seattle                 Ring 5                                  6/20/2001                 4.280          36      154.08      $ [***]

Washington              DT Ring 1                               12/6/1999                 1.040          36       37.44      $ [***]
Washington              DT Ring 2                               3/27/2000                 3.983          36      143.37      $ [***]
Washington              DT Ring 3                               9/24/2001                 8.170          36      294.12      $ [***]
Washington              Ring 2                                   3/1/2000                42.515          36     1530.54      $ [***]
Washington              Ring 3                                  12/6/1999                30.525          36     1098.90      $ [***]
Washington              Ring 4                                 12/16/1999                34.525          36     1242.90      $ [***]
Washington              Ring 5                                  2/14/2000                21.094          24      506.25      $ [***]
Washington              Elden Ring                              8/20/2001                 4.680          36      168.48      $ [***]

White Plains            Ring 1                                   3/1/2000                61.373          12      736.47      $ [***]
White Plains            Sub Loop (Church - Main)                4/17/2001                 1.325           4        5.30      $ [***]

Yonkers                 Ring 1**                               11/27/2000                16.560           6      132.48      $ [***]
                                                                                                               32839.25
</Table>

Exhibit B - Page 2
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

                                   EXHIBIT B

<Table>
<Caption>
                                                    INCOMPLETE SEGMENTS
--------------------------------------------------------------------------------------------------------------------------
              SELECTED SEGMENT (BRANCH A)
----------------------------------------------------                          LENGTH OF     NUMBER    ESTIMATED     TOTAL
        CITY                        FACILITY            DELIVERY DATE       RING/SEGMENT   OF FIBERS    MILES      CHARGES
-------------      ---------------------------------    -------------       ------------   ---------  ---------   --------
<S>                <C>                                  <C>                 <C>            <C>         <C>        <C>
Chicago            DT Ring 4                              8/15/2002             3.825           24      91.80      $ [***]

Houston            HST-16 (MFN POP to WCG POP)            8/15/2002             5.400           24     129.60      $ [***]

Los Angeles        LA-11 (12 true wave)                   8/15/2002             0.660           12       7.92      $ [***]
Los Angeles        LA-2 (12 true wave)                    8/15/2002             1.282           12      15.38      $ [***]
Los Angeles        LA-3 (12 true wave)                    8/15/2002             3.177           12      38.12      $ [***]
Los Angeles        LA-4 (12 true wave)                    8/15/2002             2.540           12      30.48      $ [***]
Los Angeles        LA-6 (12 true wave)                    8/15/2002             0.460           12       5.52      $ [***]
Los Angeles        CA-12 (12 single mode)                 8/15/2002             5.700           12      68.40      $ [***]
Los Angeles        CA-13 (12 single mode)                 8/15/2002            16.500           12     198.00      $ [***]
Los Angeles        CA-15 (12 single mode)                 8/15/2002            14.000           12     168.00      $ [***]
Los Angeles        LA-1 (12 true wave)                    8/15/2002             2.300           12      27.60      $ [***]
Los Angeles        LA-7 (12 true wave)                    8/15/2002             1.700           12      20.40      $ [***]
Los Angeles        LA-8 (12 true wave)                    8/15/2002             0.650           12       7.80      $ [***]

Manhattan          48 point-to-point**                    8/15/2002            18.500           48     888.00      $ [***]

San Francisco      Great Oaks portion                     8/15/2002            15.000            4      60.00      $ [***]
San Francisco      529 Bryan portion                      8/15/2002            25.000            2      50.00      $ [***]
San Francisco      Sub Ring 1                             8/15/2002           111.070           24    2665.68      $ [***]
San Francisco      CA-25 (12 single mode)                 8/15/2002            30.300           12     363.60      $ [***]
San Francisco      CA-4 (24 true wave & 36 single mode)   8/15/2002            16.500           60     990.00      $ [***]
San Francisco      CA-43 (46 single mode)                 8/15/2002             6.900           48     331.20      $ [***]
San Francisco      CA-41 (48 single mode)                 8/15/2002            12.300           48     590.40      $ [***]
San Francisco      CA-28 (48 single mode & 48 true wave)  8/15/2002            12.500           96    1200.00      $ [***]
San Francisco      CA-40 (48 single mode & 48 true wave)  8/15/2002             6.400           96     614.40      $ [***]
San Francisco      CA-3 (24 true wave & 36 single mode)   8/15/2002             7.700           60     462.00      $ [***]
San Francisco      CA-7 (12 single mode)                  8/15/2002            18.100           12     217.20      $ [***]
San Francisco      DMB-1 (36 single mode)                 8/15/2002            19.400           36     698.40      $ [***]
San Francisco      DMB-2 (36 single mode)                 8/15/2002             2.300           36      82.80      $ [***]

Seattle            DT Ring 3                              8/15/2002             0.554            4      2.216      $ [***]
Seattle            DT Ring 4 (Vartech)                    8/15/2002             8.520            2     17.040      $ [***]
Seattle            DT Ring A-2                            8/15/2002             4.260           27    115.020      $ [***]

White Plains       WP-4 (12 single mode)                  8/15/2002             0.705           12      8.460      $ [***]
White Plains       WP-5 (12 single mode)                  8/15/2002             0.622           12      7.464      $ [***]
White Plains       WP-3 (4 leal)                          8/15/2002            30.020            4    120.080      $ [***]
                                                                                                     10201.19

GRAND TOTALS FOR ALL SEGMENTS                                                                        43040.44
</Table>

*    Notwithstanding any provision in the Fiber Lease, WCG may take less than 6
     fibers on this route.

**   Additional New York Segments - Unrestricted Fiber

Exhibit B - Page 3
<PAGE>
EXECUTION COPY                                                    CONFIDENTIAL

                                    EXHIBIT C
                                 BUILDING ACCESS

<Table>
<Caption>
                                                                                                   Acceptance Date or
                                                                                                   ESTIMATED DELIVERY DATE,
         CITY                       LOCATION                         DEMARCATION POINT             AS APPLICABLE.
------------------    --------------------------------------       ---------------------------     ------------------------
<S>                   <C>                                          <C>                             <C>
Anaheim               217 North Lemon Street                                                                      1/28/2002

Atlanta               55 Marietta (2-fiber collapsed ring)                                                        1/11/2002

Boston                8 Harrison Avenue                                                                           3/12/2001
Boston                41 Belvidere Street                                                                         3/13/2001
Boston                10 Ware Street, Cambridge                                                                   4/11/2001
Boston                210 Bent Street, Cambridge                                                                  4/11/2001
Boston                6 Bowdoin Square                                                                            4/11/2001
Boston                36 Spring Street (primary)                                                                  7/11/2001
Boston                36 Spring Street (diverse)                   Alternate splicing area1                        7/1/2002
Boston                185 Franklin                                 Alternate splicing area2                       11/1/2002

Chicago               800 Jorie Boulevard                                                                         2/26/2001
Chicago               350 Cermak                                                                                  7/11/2001
Chicago               520 South Federal (primary)                                                                 8/24/2001
Chicago               501 63rd (Downers Grove, IL)                                                                 5/1/2001
Chicago               520 South Federal (diverse)                  MFN zero manhole3                               7/1/2002

Dallas                2323 Bryan Street                                                                            3/9/2001
Dallas                4101 Bryan Street                                                                           5/25/2001
Dallas                2400 Ross Avenue                                                                            5/25/2001
Dallas                308 South Akard                                                                             5/25/2001
Dallas                4316 Bryan Street                                                                           1/25/2002

Houston               1121 Capitol Street                                                                          5/4/2001
Houston               1200 Clay Street                                                                             5/4/2001
Houston               12025 Interstate 45 North                                                                   1/26/2001
Houston               1291 North Post Oak Road                                                                    2/26/2002
</Table>

----------

1    MFN will terminate Lessee Fiber at MFN's termination point and splice and
     test to Williams-owned riser.

2.   MFN will terminate Lessee Fiber at MFN's termination point and splice and
     test to Williams-owned riser.

3.   MFN, at its cost, will interconnect Lessee Fiber between the Demarcation
     Point and an assigned Ameritech manhole #221. Williams is responsible for
     connection from within the central office to the Ameritech manhole.
     Williams acknowledges that this route is not physically diverse as both
     MFN-serving manholes are located on same side of building.

Exhibit C - Page 1

<PAGE>
EXECUTION COPY                                                    CONFIDENTIAL

<Table>
<Caption>
                                                                                                   Acceptance Date or
                                                                                                   ESTIMATED DELIVERY DATE,
         CITY                       LOCATION                         DEMARCATION POINT             AS APPLICABLE.
------------------    --------------------------------------       ---------------------------     ------------------------
<S>                   <C>                                          <C>                             <C>
Los Angeles           1200 West 7th Street                                                                        7/25/2001
Los Angeles           433 South Olive                                                                             9/21/2001
Los Angeles           600 West 7th (Equinix)                       MFN racks within  Equinix4                      7/1/2002

New York              210 West 18th Street                                                                        2/28/2001
New York              230 West 36th Street                                                                        2/28/2001
New York              227 East 30th Street                                                                        2/28/2001
New York              435 West 50th Street                                                                        1/16/2001
New York              228 East 56th Street                                                                        1/16/2001
New York              1095 Avenue of the Americas                                                                 1/16/2001
New York              104 Broad Street                                                                            3/14/2001
New York              111 Main Street, White Plains                                                               2/13/2001
New York              221 East 37th Street                                                                         3/5/2001
New York              204 Second Avenue                                                                            3/5/2001
New York              140 West Street                                                                              3/5/2001
New York              25 Broadway                                                                                 3/15/2001
New York              111 Main Street, White Plains                                                               4/17/2001
New York              230 West 36th Street                                                                        9/10/2001
New York              227 East 30th Street                                                                        9/10/2001
New York              65 Broadway (SDFC)5                              MFN rack at SDFC                           8/30/2002
New York              32 Avenue of the Americas (TBD)               24th Floor meet-me-room                       8/30/2002
New York              395 Hudson (Colo.com)                          MFN rack at Colo.com                         8/30/2002

New Jersey            275 Hartz Way, Secaucus (Equinix)                       tbd6                               Indefinite

Philadelphia          1631 Arch Street                                                                            8/22/2001

San Francisco         555 Pine                                                                                    5/18/2001
San Francisco         611 Folsom                                                                                  5/18/2001
San Francisco         529 Bryant Street, Palo Alto (PAIX)7             MFN rack in PAIX                           7/30/2002

Santa Clara           50 West San Fernando                                                                        5/11/2001

Seattle               1122 Third Avenue                                                                          11/15/2001
Seattle               1708 East Pike Street                                                                      11/15/2001
Seattle               14808 SE 16th Street                                                                         1/4/2002
Seattle               2308 Sixth Avenue                                                                           9/28/2002
</Table>

----------

4    Delivery Date conditioned upon MFN's successful execution of agreement with
     Equinix to utilize Equinix duct.

5    Williams must procure additional fiber miles to connect this location to 25
     broadway.

6    MFN cannot at this time provide an estimated Delivery Date for Secaucus,
     but shall provide Lessee with periodic updates on the progress of this
     Building Access.

7    Two-fiber point-to-point to MFN POP at 95 S. Market Street.

Exhibit C - Page 2
<PAGE>
EXECUTION COPY                                                    CONFIDENTIAL

<Table>
<Caption>
                                                                                                   Acceptance Date or
                                                                                                   ESTIMATED DELIVERY DATE,
         CITY                       LOCATION                         DEMARCATION POINT             AS APPLICABLE.
------------------    --------------------------------------       ---------------------------     ------------------------
<S>                   <C>                                          <C>                             <C>
Washington, D.C.      1200 H Street NW                                                                             4/4/2001
Washington, D.C.      2055 L Street NW                                                                             4/4/2001
Washington, D.C.      730 12th Street NW                                                                           4/4/2001
Washington, D.C.      7990 Science Applications Boulevard                                                         7/16/2001
Washington, D.C.      21715 Filigree Court, Ashburn, VA (primary)                                                 7/25/2001
Washington, D.C.      21715 Filigree Court, Ashburn, VA (diverse)      MFN rack inside Equinix                    7/30/2002
Washington, D.C.      8502-A Tyco Road (SDFC)                           MFN rack inside SDFC                      7/30/2002
</Table>

Exhibit C - Page 3
<PAGE>

EXECUTION COPY                                                    CONFIDENTIAL

                                    EXHIBIT D

                                FORM OF AS-BUILTS

1.        Alignment Sheets

A.        As-Built Alignment Sheets shall include the following information:

     o    Cable Information: cable type, fiber type, reel number, cable
          composition

     o    Right-of-Way: landowner/facility owner, border locations (per
          muncipality)

     o    Route Information: manhole/handhole location and number,
          manhole/handhole size and ownership, splice locations, cable length
          markers at splice points and slack coils, splice enclosure type,
          attachment height (when applicable), pole number (when applicable),
          bore location (when applicable), bridge/tunnel attachment (when
          applicable), offset and depty (when applicable), location of utility
          crossings, location of reference points/permanent structures,
          transitional points, street names, conduit and innerduct position
          information/butterflies

B.        As-Built Alignment Sheets shall be updated with actual construction
field data.

C.        The scale of As-Built Alignment Sheets shall not exceed 1" = 200' in
metropolitan areas (areas where there is either extensive development and
improvement or rapid growth (new building construction)) or 1" = 500' in
non-metropolitan areas.

2.        Format

Drawings shall be "blue lines", as such term is understood in the industry or in
CAD format revision 14 or a later revision. MFN may, after the Acceptance Date,
adopt any replacement method of creating or providing drawings that is generally
accepted in the industry and that provides equivalent information.

3.        Transmission Site Floor Plans

Floor plans for Transmission Sites shall show rack placement and assignment for
Lessee's floor space.

Exhibit D - Page 1
<PAGE>

EXECUTION COPY                                                    CONFIDENTIAL

                                    EXHIBIT E

                                MFN DATA CENTERS

LA1                                               VA2
2260 East El Segundo Boulevard                    1807 Michael Faraday Court
El Segundo, CA  90245                             Reston, VA  20190

NY1                                               VA4
111 8th Avenue #209                               2051 Chain Bridge Road
New York, NY  10011                               Vienna, VA 22182

NY2
111 8th Avenue 6th Floor
New York, NY  10011

SEA2
3433 South 120th Place
Tukwila, WA  98168

SF1
365 Main Street
San Francisco, CA  94105

SJ1
50 W. San Fernando Street, 18th Floor
San Jose, CA  95113

SJ2
150 South First Street, #289
San Jose, CA  95113

SJ3
1735 Lundy Avenue
San Jose, CA   95131

VA1
8100 Boone Boulevard, Suite 110
Vienna, VA  22182

Exhibit E - Page 1

<PAGE>
EXECUTION COPY                                                    CONFIDENTIAL

                                    EXHIBIT F

                           CONSTRUCTION SPECIFICATIONS

1.0  GENERAL

The intent of this document is to outline the specifications for construction of
a fiber optic cable system. In all cases, the standards and specifications
contained in this document or the applicable standards and specifications of
federal, state, local or private agencies having jurisdiction, whichever is
stricter, shall be followed.

2.0  MATERIAL

o    Steel or PVC conduit used in any aspect of this construction effort shall
     have at least (minimum) Schedule 40 wall thickness.

o    Any exposed steel conduit, brackets or other hardware (such as bridge
     attachments) shall be hot dipped galvanized following fabrication to resist
     corrosion.

o    All split steel shall be flanged.

o    All handholds (fiber optic cable splice points) shall have a minimum
     loading rating of H20 with 24 inches of cover ( for railroads or non-street
     applications). For street applications, handholds /covers will be buried
     flush with the road surface.

o    All manholes shall have a minimum loading rating of H20.

o    All innerducts shall be one and one quarter inches (1.25") in diameter or
     the smallest diameter size possible to allow the pulling of the fiber optic
     cable as specified elsewhere in this document.

o    Buried cable warning tape ( stretch type ) shall be three (3) inches wide
     and display the following information: "Warning: Buried Fiber Optic Cable",
     Company Name and Logo, local and emergency One Call "800" telephone
     numbers. This information shall be repeated along the warning tape at
     intervals of no more than 24 inches.

o    Warning signs or stakes will display the universal " Do Not Dig" symbol. In
     addition, the warning signs or stakes shall also display the following
     information: "Warning: Buried Fiber Optic Cable", Company Name and Logo,
     local and emergency One Call "800" telephone numbers.

Exhibit F - Page 1
<PAGE>

EXECUTION COPY                                                      CONFIDENTIAL

3.0  MINIMUM DEPTHS OF CABLE AND CONDUITS.

The minimum cover required in the placement of fiber optic cable, conduit or
inner duct shall be 42 inches except in the following instances:

o    The minimum cover in borrow ditches adjacent to roads, highways, railroads
     and interstate highways shall be 48 inches below the cleanout line or
     existing grade, whichever is greater.

o    The minimum cover across streams, river washes and other waterways shall be
     60 inches below the cleanout line or existing grade, whichever is greater.

o    At locations where the fiber optic cable, conduit or inner duct crosses
     other sub-surface utilities or other structures, the fiber optic cable,
     conduit or inner duct shall be installed in such a way as to provide a
     minimum of 12 inches of vertical clearance between it and other sub-surface
     utilities or other structures as well as maintain the applicable minimum
     depth requirement. To maintain the minimum applicable depth requirement,
     the fiber optic cable, conduit or inner duct shall be installed under the
     existing utility or other structure. If the 12 inch vertical separation
     between the fiber optic cable and other utility or structure cannot be
     obtained, then the fiber optic cable shall be encased in steel pipe.

o    In rock, the fiber optic cable, conduit or inner duct shall be placed to
     provide a minimum of 18 inches below the surface of the solid rock, or
     provide a minimum of 42 inches of total cover, whichever requires the least
     amount of rock excavation. For cover depths of 18 inches to 24 inches,
     steel pipe is required. Cover depths of 24 inches or greater do not require
     steel pipe.

o    In the case where existing steel pipelines, ducts or conduits are to be
     utilized, the existing depth shall be considered as adequate.

4.0  BURIED CABLE WARNING TAPE.

o    All fiber optic cable, conduit and inner duct shall be installed with
     buried cable (stretch Type) warning tape except where existing steel
     pipelines, conduits or other salvaged conduit systems are used. The warning
     tape as specified earlier in this document shall be placed as follows. One
     layer of warning tape shall be placed directly on top of the fiber optic
     cable, conduit or inner duct. A second layer of warning tape shall be
     placed at a depth of 12 inches below grade.

5.0  CONDUIT/INNER DUCT CONSTRUCTION.

o    All conduits or inner ducts may be placed and installed by means of
     trenching, plowing, jack and bore, mini-directional bore or directional
     bore. All conduits or inner ducts will generally be placed on level grade,
     parallel to the surface and with only gradual changes in grade elevation.

Exhibit F - Page 2
<PAGE>

EXECUTION COPY                                                      CONFIDENTIAL

o    Steel conduit will be joined with threaded collars, Zap-Lok or through
     welding. (Welding is the preferred joining method)

o    All paved city, state, federal and interstate highway and railroad
     crossings will be encased in HDPE or steel conduit. If the crossings are at
     grade, steel conduit is not required if the cable or inner duct is placed
     with a minimum of 10 feet of cover.

o    All longitudinal cable runs under paved streets shall be placed in steel,
     HDPE or PVC conduit.

o    Metro areas shall be defined for the purpose of this document as follows:

        a)  There are more than three (3) paved public road crossings per mile.

        b)  There are more than six (6) utility crossings per mile.

        c)  Developed and/or improved areas.

        d)  High growth areas.

        Note: Railroad right-of-ways are not considered metro areas.

o    All fiber optic cable crossings of major streams, rivers, bays and
     navigable waterways shall be placed in HDPE, PVC or steel conduit.

o    At all other utility or other underground obstacle crossings, the fiber
     optic cable shall be placed in split or solid steel conduit and the conduit
     will extend at least ten (10) feet beyond the edges of the obstacle in both
     directions.

o    All jack and bores will utilize steel conduit.

o    All directional and mini-directional bores will utilize HDPE or steel
     conduit.

o    Fiber optic cable placed in rock will be installed in HDPE, PVC or steel
     conduit.

o    Fiber optic cable placed in swampy or wetland areas will be installed in
     HDPE, PVC or steel conduit.

o    Fiber optic cable placed on bridges shall be installed in steel conduit and
     the conduit shall have expansion joints placed at each structural (bridge)
     expansion joint or at the minimum every 150 feet, whichever is the shorter
     distance.

o    Whenever steel, HDPE or PVC conduit is installed, it must have inner ducts
     placed inside of it. No fiber optic cable shall be run directly in a solid
     conduit. The fiber optic cable must be installed inside one of the inner
     ducts within the solid conduit.

Exhibit F - Page 3
<PAGE>
EXECUTION COPY                                                      CONFIDENTIAL

6.0  FIBER OPTIC CABLE INSTALLATION.

o    The fiber optic cable shall be installed by using a powered pulling winch
     and hydraulic powered assist wheels. The maximum pulling force applied to
     the fiber optic cable shall not exceed six hundred (600) pounds or as
     specified by the cable manufacturer. Sufficient pulling assists must be
     available and used to ensure that the maximum pulling force is never
     exceeded at any point along the pull. In addition, the following shall also
     be applied:

        a)  The cable shall be lubricated during all pulls.

        b)  A pulling swivel break away rated at 600 pounds of force (or as
            specified by cable manufacturer shall be used at all times.

        c)  All fiber optic splices shall be made in handholds or manholes.

        d)  A minimum of 20 meters of fiber optic cable slack shall be left at
            all intermediate handholds or manholes where no cable splicing takes
            place.

        e)  A minimum of 30 meters of fiber optic cable slack is to be left at
            all handhold and manhole cable splice locations.

        f)  A minimum of 50 meters of fiber optic cable slack is to be left in
            all facility locations such as POP sites, regenerator locations,
            amplifier locations or terminal locations.

        g)  All contractors that handle the cable will be required to attend
            manufacturer sponsored training classes.

7.0  MANHOLES AND HANDHOLDS.

o    Manholes shall be placed in traveled surface streets and shall have locking
     lids.

o    Handholds shall be placed in all other areas and they shall be installed
     with 24 inches of soil covering the handhold lid. All handholds locations
     shall be identified with cable markers on either side of the handhold with
     exact and specific information as to the location of the handhold.

o    All handhold and manhole locations shall be clearly marked on all
     installation as-build drawings.

o    Carrots ( location toning devices ) will be installed on all buried
     Manholes or Handholds. Carrots will be supplied by the Owner.

8.0  CABLE MARKERS (WARNING SIGNS).

o     Cable markers shall be installed at all locations where changes in cable
      running line direction occur, at all fiber optic cable manhole/handhold
      splice points, pullboxes and assist points as well as at both sides of
      street, road, highway or railroad crossing. Under no circumstances,

Exhibit F - Page 4
<PAGE>
EXECUTION COPY                                                      CONFIDENTIAL

     shall any markers be spaced more than 500 feet apart in metro areas and
     more than 1000 feet apart in non-metro areas. Markers shall always be
     positioned in such a way so that they can be seen from the route of the
     cable and they should be installed, generally, in the direction
     perpendicular to the cable route line.

o    All handholds, manholes, splice points, assists shall be indicated on the
     marker posts. The fiber optic cable metallic member shall be grounded at
     all fiber optic cable splice point locations. A tone system will be
     utilized for cable locates, with locate terminals placed at each fiber
     optic splice point location. The locate dial up units will be placed at
     every equipment shelter along the fiber optic cable route. The locating
     tone will be carried by the metallic sheath which is part of the fiber
     optic cable assembly.

9.0  SAFETY AND ENVIRONMENTAL CONSIDERATIONS.

o    All work described in this document shall be performed in strict accordance
     with all applicable federal, state, local and private rules, laws and
     regulations relating to safety and environmental issues, including those
     set forth by OSHA and the EPA.

10.0 CABLE SPLICING AND TESTING IN THE FIELD. ( SEE DETAILED SPLICING AND
     TESTING REQUIREMENTS -EXHIBIT A )

o    The fiber optic cables entering a splice case within a splice manhole or
     handhold shall be on the same side of the case. No so called "in-line"
     splices shall be allowed.

o    Only splices from one buffer tube shall be housed in any splice tray. Under
     no circumstances will a fiber optic cable buffer tube be split between two
     or more splice trays.

o    Under no circumstances will jumpers be allowed from tray to tray.

o    All fiber splices shall be matched up color-to-color in both the buffer
     tubes and individual fiber strand cladding. Under no circumstances will
     "frogging" of fiber strands be permitted.

o    All splices shall be made with a profile alignment fusion splicing machine.
     All splices shall protected by heat shrink tubing.

o    Fiber Optic Cable Splicing, Testing and Acceptance Procedures are outlined
     in a separate attachment to this document. (Exhibit A)

Exhibit F - Page 5
<PAGE>
EXECUTION COPY                                                      CONFIDENTIAL

11.0 TERMINATION OF FIBER OPTIC CABLE.

o    All fiber optic strands within the MFNS fiber optic cable will be
     terminated on MFNS provided and designated bulkheads or fiber distribution
     panels located at all MFNS regenerator, amplifier, terminal, junction and
     POP locations along the MFNS fiber route.

NOTES:

This document outlines MFN construction specifications. These specifications are
not applicable to the entire MFN network. However, all segments have been
constructed to generally acceptable industry best practices.

Exhibit F - Page 6
<PAGE>
EXECUTION COPY

CONFIDENTIAL PORTION MARKED [*************] HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT AND FILED SEPARATELY WITH THE SECURITIES
AND EXCHANGE COMMISSION.

                       FIRST AMENDMENT TO LEASE AGREEMENT

         THIS FIRST AMENDMENT (this "Amendment") is made by and between
METROMEDIA FIBER NETWORK SERVICES, INC., a Delaware corporation ("MFN") and
WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability company ("Lessee").

                                   Background

Lessee and MFN are parties to the Lease Agreement dated April 26, 2002 (the
"Agreement").

On May 20, 2002, MFN and most of its direct and indirect domestic subsidiaries
each filed voluntary petitions for reorganization pursuant to Chapter 11 of
title 11 of the United States Code (the "Bankruptcy Code") with the United
States Bankruptcy Court for the Southern District of New York (the "Bankruptcy
Court") and MFN is currently operating its business and managing its property as
a debtor-in-possession (the "Pending Bankruptcy Case").

The parties now wish to amend the Agreement in accordance with the terms set
forth in this Amendment.

NOW THEREFORE, for mutual consideration, the value of which the parties
acknowledge, the terms of the Agreement are amended as follows:

1. Capitalized terms not otherwise defined in this Amendment have the meaning
ascribed in the Agreement.

2. The definition of "Term" is deleted and replaced with the following:

"'TERM' begins on the date of full execution of the First Amendment to this
Agreement and includes the initial term and any subsequent renewal terms."

3. Section 3.1 is deleted and replaced with the following:

"During the Term, unless otherwise converted to an IRU pursuant to Section 3.6,
MFN grants to Lessee a Lease in 30,740 fiber miles in the MFN System (the
'Lessee Fiber'). The Lessee Fiber is identified by segment in Exhibit B-1.
Lessee agrees to pay the fees set forth in Section 4.1 for the Lessee Fibers.
[************************************************************
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*************************************************************************
****************************************************************************
***********************************************************************
****************************************************************************
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CONFIDENTIAL
PAGE 1 OF 4

<PAGE>

EXECUTION COPY

4. The following Section 3.6 is added to the Agreement:

"TERM. The initial term of the agreement expires [*********] years after the
effective date of the First Amendment to this Agreement, with [***************]
renewal periods. Unless Lessee provides a minimum of 60 days notice of
termination prior to the expiration of the then-current term, the Agreement
automatically renews under the same terms and conditions."

5. EXHIBITS B AND C are wholly replaced with EXHIBIT B-1 AND C-1, attached to
this Amendment.

6. The following Section 17.7 is added to the Agreement:

"CROSS DEFAULT. MFN and Lessee are parties to a second Lease Agreement dated
April 26, 2002 pursuant to which MFN is the lessee (the "Longhaul Agreement").
The parties agree that a default under the Longhaul Agreement is deemed a
default under this Agreement, giving the non-defaulting party the right to
terminate if the Longhaul Agreement is likewise terminated. The right to
terminate under this Section 17.7 automatically expires if the non-defaulting
party does not provide notice, within 60 days of termination of the Longhaul
Agreement, of its intent to exercise its right to terminate this Agreement. Such
termination shall be effective 120 days after such notice, if given.

7. Section 20.3(b) is deleted and replaced with the following:

[****************************************************************************
*****************************************************************************
**************************************************************************
**************************************************************************
************************************************************************
*******************************************************************************]

8. ADDITIONAL CONSIDERATION; PRE-PETITION CURE. The parties agree to effect a
pre-petition netting in Bankruptcy Court for all pre-petition amounts owed
between Metromedia Fiber Network Services, Inc., Metromedia Fiber National
Network, Inc.(together "Debtor"), and Williams Communications, LLC. The parties
acknowledge and agree, that after netting, Debtor owes Williams Communications,
LLC [*************] in pre-petition obligations (the "Prepetition Debt"). As
full satisfaction of the Prepetition Debt, Debtor agrees to provide to Williams
a credit against monthly invoices issued under the Agreement over the initial
3-year term as follows:

      o     months 1-12 [*******] per month

      o     months 13-24 [*******] per month

      o     months 24-36 [*******] per month

9. EFFECTIVE DATE. This Amendment is effective upon the date of the last
signature hereto ("Effective Date"). The parties agree that the new billing rate
as specified in paragraph 3 of this Amendment is effective October 1, 2002. To
be sure, any invoices rendered during September

CONFIDENTIAL
PAGE 2 OF 4

<PAGE>

EXECUTION COPY

2002 for October services, will be adjusted accordingly. Notwithstanding the
foregoing, the parties acknowledge that the Amendment must be approved by the
Bankruptcy Court pursuant to an order, in form and substance acceptable to
Lessee and MFN, which provides for, among other things, the following: (i)
assumption of the Agreement, as amended, pursuant to section 365 of the
Bankruptcy Code, and (ii) a finding that the parties negotiated the Amendment at
arm's length and in good faith. If such approval is not obtained on or before
October 17, 2002 or such later date as the parties may agree to, this Amendment
will be null and void and of no force or effect and Lessee agrees to pay the
difference between the amended amounts invoiced for October and the actual
amounts owed under the Agreement.

10. ASSUMPTION AND WAIVER OF SPECIFIC CLAIMS. If following the assumption of the
Agreement:

         (a) one or more metro fiber rings currently operated by MFN on which
Lessee has Lessee Fiber, is effectively abandoned because MFN elects no longer
to operate those markets and the markets are sold to a third party, then any
damage claim of Lessee arising from the effective abandonment of any such market
is a general unsecured claim in the Pending Bankruptcy Case; and/or

         (b) one or more, but less than all, MFN's metropolitan networks are
sold to a third party who intends to operate such networks, then, subject to
Lessee's rights under section 365 of the Bankruptcy Code as described below,
Lessee and MFN will execute a new agreement in all respects identical to the
existing Agreement but which includes only the Lessee Fiber in markets sold to a
third party. The new agreement may be assigned by MFN to the third party
pursuant to section 365 of the Bankruptcy Code, and the existing Agreement will
be deemed amended to eliminate the assigned Lessee Fiber from its scope. The
occurrence of events contemplated by this subparagraph is not a breach by MFN of
the Agreement and will not give rise to a claim. Lessee may object to any
assignment pursuant to section 365 of the Bankruptcy Code on the grounds that
Lessee is not receiving adequate assurance of future performance or that an
assignment to the third party assignee in question is otherwise not permitted
under the Bankruptcy Code; provided, however, that in the event Lessee's
objection to such assignment is sustained but the relevant network is
nevertheless sold to the third party, the parties agree that damages, if any,
arising from the breach resulting from MFN's inability to provide service to
Lessee under the Agreement with respect to the networks sold to the third party,
will be a general unsecured claim in the Pending Bankruptcy Case; or

         (c) the Agreement is terminated due to MFN's failure to perform or its
rejection thereof, nothing herein constitutes a waiver of Lessee's right to a
general unsecured claim for all outstanding Pre-Petition Debt and an
administrative claim for post-petition damages caused by any breach of the
Agreement, or of the right of MFN or any party in interest to object to any such
claim. Any and all administrative expense claims will require Williams
Communications to satisfy the requirements of the Bankruptcy Code to establish
the claim and is without prejudice to any other party's right to contest such
claim.

CONFIDENTIAL
PAGE 3 OF 4
<PAGE>

EXECUTION COPY

         MFN further hereby agrees to waive its right to assert any bankruptcy
preference claim, fraudulent transfer claim or any other potential avoidance
claims available to MFN against Customer arising out of the Agreement.

11. Except as amended, all of the original terms and conditions of the Agreement
continue in full force and effect, neither party is in currently in default, and
the Agreement, as amended is hereby ratified and confirmed.

12. This Amendment may be executed in counterparts, each of which taken together
constitute one and the same instrument.

The parties have executed this Amendment on the dates set forth below.

METROMEDIA FIBER NETWORK SERVICES, INC., a Delaware corporation

Signature:        /s/ William G. La Perch
          -------------------------------------

(Print) Name:     William G. La Perch
              ---------------------------------

(Print) Title:    Sr. Vice President
              ---------------------------------

(Print) Date:     10/10/02
             ----------------------------------

WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability company

Signature:        /s/ Frank M. Semple
          -------------------------------------

(Print) Name:     Frank M. Semple
              ---------------------------------

(Print) Title:    Chief Operating Officer
              ---------------------------------

(Print) Date:     10/2/02
             ----------------------------------

CONFIDENTIAL
PAGE 4 OF 4

<PAGE>
EXECUTION COPY

                                  EXHIBIT B-1

<Table>
<Caption>
                       SELECTED SEGMENT (BRANCH A)                     LENGTH OF     NUMBER       FIBER
CITY            FACILITY                        ACCEPTANCE DATE       RING/SEGMENT   OF FIBERS    MILES                MRC
----            --------                        ---------------       ------------   ---------    ------               ---
<S>             <C>                             <C>                     <C>          <C>         <C>            <C>
Atlanta         56 Marietta (Atlanta 2A)             2/12/2001           2.45            4           9.80        [*************]

Atlanta         DT Ring 1                            7/17/2001           7.70           12           92.40       [*************]

Atlanta         56 Marietta - 874 DeKalb            11/12/2001           2.45           32           78.40       [*************]

Boston          DT Ring 1                            2/24/2000           7.99           28          223.79       [*************]

Boston          DT Ring 2                            7/28/2000           8.36           16          133.78       [*************]

Boston          DT Ring 3                            5/16/2000           5.82           28          162.96       [*************]

Boston          Sub-Ring 2
                (Boston to Spring Street)            7/11/2001          16.00            4           64.00       [*************]

Boston          Sub-Ring 2                           1/21/2002          35.25           28          987.00       [*************]

Central
New Jersey      Ring 1                               7/11/2000          81.00            6          486.00       [*************]

Chicago         DT Ring 1                             2/8/2000           3.42           16           54.72       [*************]

Chicago         DT Ring 2                            3/10/2000           1.70           16           27.18       [*************]

Chicago         DT Ring 3                            3/10/2000           2.36           16           37.80       [*************]

Chicago         DT Ring 4                             2/8/2000           3.83           24           91.80       [*************]

Chicago         DT Ring 5                            3/10/2000           3.39           16           54.30       [*************]

Chicago         DT Ring 6                             2/8/2000          14.78           12          177.30       [*************]

Chicago         Ring 5 (Sub-Ring 5)                  2/28/2000          14.38            6           86.29       [*************]

Chicago         Ring 7 (DT Ring 7)                   7/11/2001           5.50           12           66.00       [*************]

Chicago         Sub-Ring 2                           9/15/2000          86.50           12         1037.99       [*************]

Chicago         Sub-Ring 3                            4/4/2001          74.00            8          592.00       [*************]

Chicago         Sub-Ring 4                           7/14/2000          41.88            8          335.02       [*************]

Chicago         Sub-Ring 5 (Additional)              12/6/2001          14.38           18          258.84       [*************]

Dallas          Ring 1                                2/7/2000          30.57           24          733.74       [*************]

Dallas          Ring 2                               2/14/2000          66.77           24         1602.45       [*************]

Dallas          Ring 3                               2/28/2000          41.37           12          496.38       [*************]

Dallas          Ring 4                               5/16/2000          71.90            8          575.19       [*************]
</Table>

CONFIDENTIAL

                                   EXHIBIT B-1

<PAGE>
<Table>
<Caption>
                       SELECTED SEGMENT (BRANCH A)                     LENGTH OF     NUMBER       FIBER
CITY            FACILITY                        ACCEPTANCE DATE       RING/SEGMENT   OF FIBERS    MILES                MRC
----            --------                        ---------------       ------------   ---------    ------               ---
<S>             <C>                             <C>                     <C>          <C>         <C>            <C>
Denver          CBD                                    6/21/2001              6.21         12      74.52           [*************]

Houston         Ring 1 (DT 1)                          7/14/2000              7.38         24     177.12           [*************]

Houston         Ring 2 (DT 2)                          7/14/2000              4.01         12      48.06           [*************]

Houston         Ring 3                                 7/14/2000             60.53         16     968.40           [*************]

Houston         Ring 4                                 7/14/2000             55.97         18    1007.46           [*************]

Houston         Ring 5                                 7/14/2000             48.06          8     384.48           [*************]

Houston         Ring 5A                                8/15/2000             12.50          4      50.01           [*************]

Houston         Ring 6                                 7/14/2000             11.15         12     133.79           [*************]

Houston         Ring 7                                 10/1/2001             63.15          4     252.60           [*************]

Long Island     Ring South (Ring 1)                    8/17/2000             62.41         12     748.87           [*************]

Los Angeles     DT Ring 1                              5/14/2001              1.34         20      26.80           [*************]

Los Angeles     DT Ring 2                              5/17/2001              2.66         20      53.20           [*************]

Los Angeles     DT Ring 3                              5/24/2001              3.70         20      74.00           [*************]

Los Angeles     DT Ring 4                             10/17/2001              5.72         20     114.40           [*************]

Los Angeles     DT Ring 5                               8/7/2001              1.04         48      49.68           [*************]

Los Angeles     Sub-Ring 1
                (Lemon point-to-point)                 1/28/2002              8.51          2      17.02           [*************]

Manhattan       Ring 3                                  2/4/2000              5.86         60     351.81           [*************]

Manhattan       Ring 4                                 3/13/2000              3.99         60     239.67           [*************]

Manhattan       Ring 5                                 1/28/2000              3.39         60     203.31           [*************]

Manhattan       Ring 6-1                                2/1/2000             12.76         48     612.54           [*************]

Manhattan       Ring 6-2                               9/16/2000             11.75         12     140.94           [*************]

Manhattan       Ring 7                                  2/4/2000              8.03          6      48.15           [*************]

New Jersey      Ring 1                                 6/13/2000            113.40         12    1360.80           [*************]

New York City   Ring 2 (Manhattan 2) consol.                                  4.79         57     272.86           [*************]

New York City   POP 1 to POP 2
                Interconnection (1-24)                 4/16/2002              3.70         24     444.00           [*************]

New York City   POP 1 TO POP 2
                Interconnection (25-48)                    TBD                3.70         24     444.00           [**************]
</Table>

CONFIDENTIAL

                                   EXHIBIT B-1

<PAGE>

<Table>
<Caption>
                       SELECTED SEGMENT (BRANCH A)                     LENGTH OF     NUMBER       FIBER
CITY            FACILITY                        ACCEPTANCE DATE       RING/SEGMENT   OF FIBERS    MILES                MRC
----            --------                        ---------------       ------------   ---------    ------               ---
<S>             <C>                             <C>                     <C>          <C>         <C>            <C>
Newark -
 60 Hudson      Revised & Consolidated Billing        1/28/2000        42.76           24       1026.24         [*************]

NY - Boston     95 Church Street - 230 Congress          TBD          203.88            2        407.76         [*************]

NY - Boston     60 Hudson - 230 Congress              2/23/2000       278.88            2        557.76         [*************]

Philadelphia    DT Ring 1                             2/23/2000         4.13           20         82.50         [*************]

Philadelphia    DT Ring 2                             3/27/2000         5.44           20       108.75          [*************]

Philadelphia    DT Ring 3                             3/27/2000         5.75           20       115.05          [*************]

Philadelphia    Ring 4                                6/11/2001         4.17            8        33.36          [*************]

Philadelphia    KP Loop                               3/27/2000         9.96            4        39.84          [*************]

Philadelphia    Main Ring                             3/27/2000        56.47            4       225.86          [*************]

Phoenix         CBD                                   7/17/2001         9.00           12       108.00          [*************]

San Francisco   DT Ring 1                             6/15/2000         7.20           20       144.00          [*************]

San Francisco   DT Ring 2                             6/15/2000         5.90           20       118.00          [*************]

San Francisco   DT Ring 3                             6/13/2000         3.56           20        71.20          [*************]

San Francisco   DT Ring 4                             6/18/2000         2.80           20        56.00          [*************]

San Francisco   Dunbarton (DMB-1 & DMB-2)             5/13/2002        22.63           20       452.60          [*************]

San Francisco   Oakland Ring (Ring 4)                 2/11/2002         2.38           12        28.58          [*************]

San Francisco   8-fiber point-to-point
                for Pine/Folsum                       1/30/2001         5.76            8        46.10          [*************]

San Francisco   Sub Ring 1                             5/9/2002       111.07           24      2665.68          [*************]

San Francisco   CA-7                                   5/9/2002        16.10           12       193.20          [*************]

San Francisco   CA-3 & CA-4                            5/9/2002        26.90           12       322.80          [*************]

San Francisco   11 Great Oaks CA25 cable              10/1/2002        14.00            4        56.00          [*************]

San Francisco   529 Bryan (portions of
                CA-3 & CA-4)                          8/23/2002        25.00            2        50.00          [*************]

Santa Clara     50 West Fernando                      5/11/2001         0.34            4         1.36          [*************]

Seattle         DT Ring 1                             8/15/2001         4.42           24       105.96          [*************]

Seattle         DT Ring 2                              9/6/2001         9.25           24       222.00          [*************]

Seattle         DT Ring 3                             8/15/2001         4.49           24       107.76          [*************]
</Table>

CONFIDENTIAL

                                   EXHIBIT B-1

<PAGE>
<Table>
<Caption>
                       SELECTED SEGMENT (BRANCH A)                     LENGTH OF     NUMBER       FIBER
CITY            FACILITY                        ACCEPTANCE DATE       RING/SEGMENT   OF FIBERS    MILES                MRC
----            --------                        ---------------       ------------   ---------    ------               ---
<S>             <C>                             <C>                     <C>          <C>         <C>            <C>

Seattle         DT Ring 3/4 (between
                Skinner & Weston)                      8/15/2001          0.55            4         2.22          [*************]

Seattle         DT Ring 3/4 (fiber ring
                to STTLWA03 & 06)                     11/15/2001          7.60            2        15.20          [*************]

Seattle         DT Ring 4 (1505 5th - 2001 6th)         3/5/2001          4.26            3        12.78          [*************]

Seattle         DT Ring 4 (1505 5th - 2308 6th)        3/29/2002          4.26            2         8.52          [*************]

Seattle         Lake Washington Ring
                (fibers to Bellevue)                    1/4/2002         79.08            2       158.16          [*************]

Seattle         Lake Washington Ring
                (between Skinner & Weston)             3/14/2002          0.54            4         2.16          [*************]

Seattle         Lake Washington Ring                   3/14/2002         76.55           12       918.60          [*************]

Seattle         DT Ring 5                              6/20/2001          4.28           24       102.72          [*************]

Washington      DT Ring 1                              12/6/1999          1.04           36        37.44          [*************]

Washington      DT Ring 2                              3/27/2000          3.98           36       143.37          [*************]

Washington      DT Ring 3                              9/24/2001          8.17           36       294.12          [*************]

Washington      Ring 2                                  3/1/2000         42.52           36      1530.54          [*************]

Washington      Ring 3                                 12/6/1999         30.53           36      1098.90          [*************]

Washington      Ring 4                                12/16/1999         34.53           20       690.50          [*************]

Washington      Ring 5                                 2/14/2000         21.09           20       421.88          [*************]

Washington      Elden Ring                             8/20/2001          4.68           36       168.48          [*************]

White Plains    Ring 1                                  3/1/2000         61.37           12       736.47          [*************]

White Plains    Sub Loop (Church - Main)               4/17/2001          1.33            4         5.30          [*************]

White Plains    WP-2                                   4/26/2002         37.50            4       150.00          [*************]

Yonkers         Ring 1                                11/27/2000         16.56            8       132.48          [*************]
                                                                                               ---------
                                                                                               30,739.80          [*************]
</Table>

CONFIDENTIAL

                                   EXHIBIT B-1

<PAGE>

EXECUTION COPY

                                   EXHIBIT C-1
                                 BUILDING ACCESS

<Table>
<Caption>
                                                                                ACCEPTANCE DATE OR
                                                                              ESTIMATED DELIVERY DATE,
      CITY                   LOCATION                  DEMARCATION POINT          AS APPLICABLE.
      ----                   --------                  -----------------      ------------------------
<S>                  <C>                               <C>                    <C>
Anaheim              217 North Lemon Street                                          1/28/2002

Atlanta              55 Marietta (2-fiber collapsed
                     ring)                                                           1/11/2002

Boston               8 Harrison Avenue                                               3/12/2001
Boston               41 Belvidere Street                                             3/13/2001
Boston               10 Ware Street, Cambridge                                       4/11/2001
Boston               210 Bent Street, Cambridge                                      4/11/2001
Boston               6 Bowdoin Square                                                4/11/2001
Boston               36 Spring Street (primary)                                      7/11/2001

Chicago              800 Jorie Boulevard                                             2/26/2001
Chicago              350 Cermak                                                      7/11/2001
Chicago              520 South Federal (primary)                                     8/24/2001
Chicago              501 63rd (Downers Grove, IL)*                                    5/1/2001

Dallas               2323 Bryan Street                                                3/9/2001
Dallas               4101 Bryan Street                                               5/25/2001
Dallas               2400 Ross Avenue                                                5/25/2001
Dallas               308 South Akard                                                 5/25/2001
Dallas               4316 Bryan Street *                                             1/25/2002

Houston              1121 Capitol Street                                              5/4/2001
Houston              1200 Clay Street                                                 5/4/2001
Houston              12025 Interstate 45 North                                       1/26/2001
Houston              1291 North Post Oak Road                                        2/26/2002

Los Angeles          1200 West 7th Street                                            7/25/2001
Los Angeles          433 South Olive                                                 9/21/2001

New York             210 West 18th Street                                            2/28/2001
New York             230 West 36th Street                                            2/28/2001
New York             227 East 30th Street                                            2/28/2001
New York             435 West 50th Street                                            1/16/2001
New York             228 East 56th Street                                            1/16/2001
New York             1095 Avenue of the Americas                                     1/16/2001
New York             104 Broad Street                                                3/14/2001
New York             111 Main Street, White Plains                                   2/13/2001
New York             221 East 37th Street                                             3/5/2001
New York             204 Second Avenue                                                3/5/2001
New York             140 West Street                                                  3/5/2001
</Table>

CONFIDENTIAL
                                        EXHIBIT C-1

<PAGE>
<Table>
<Caption>
                                                                                ACCEPTANCE DATE OR
                                                                              ESTIMATED DELIVERY DATE,
      CITY                   LOCATION                  DEMARCATION POINT          AS APPLICABLE.
      ----                   --------                  -----------------      ------------------------
<S>                  <C>                               <C>                    <C>

New York             25 Broadway                                                     3/15/2001
New York             111 Main Street, White Plains                                   4/17/2001
New York             230 West 36th Street                                            9/10/2001
New York             227 East 30th Street                                            9/10/2001

Philadelphia         1631 Arch Street                                                8/22/2001

San Francisco        555 Pine                                                        5/18/2001
San Francisco        611 Folsom                                                      5/18/2001
San Francisco        11 Great Oaks Blvd                                              10/1/2002
San Francisco        529 Bryant Street, Palo Alto            MFN rack in PAIX
                     (PAIX)(1)                                                         8/28/2002

Santa Clara          50 West San Fernando                                            5/11/2001

Seattle              1122 Third Avenue                                              11/15/2001
Seattle              1708 East Pike Street                                          11/15/2001
Seattle              14808 SE 16th Street                                             1/4/2002
Seattle              2308 Sixth Avenue *                                             9/28/2001

Washington, D.C.     1200 H Street NW                                                 4/4/2001
Washington, D.C.     2055 L Street NW                                                 4/4/2001
Washington, D.C.     730 12th Street NW                                               4/4/2001
Washington, D.C.     7990 Science Applications Boulevard                             7/16/2001
Washington, D.C.     21715 Filigree Court, Ashburn, VA                               7/25/2001
                     (primary)
</Table>

--------

(1) Two-fiber point-to-point to MFN POP at 95 S. Market Street.

 *  indicates Street Meet Me

CONFIDENTIAL
                                        EXHIBIT C-1

<PAGE>
EXECUTION COPY                                                     CONFIDENTIAL

CONFIDENTIAL PORTION MARKED [*************] HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT AND FILED SEPARATELY WITH THE SECURITIES
AND EXCHANGE COMMISSION.

                      COLLOCATION AND MAINTENANCE AGREEMENT

                                     BETWEEN

              METROMEDIA FIBER NETWORK SERVICES, INC. ("PROVIDER")

                                       AND

                    WILLIAMS COMMUNICATIONS, LLC ("CUSTOMER")

                              DATED APRIL 26, 2002

<PAGE>
EXECUTION COPY                                                     CONFIDENTIAL

                                TABLE OF CONTENTS

<Table>
<Caption>
ARTICLE                                                                                                PAGE
-------                                                                                                ----
<S>                   <C>                                                                              <C>
ARTICLE I             DEFINITIONS                                                                        1

ARTICLE II.           CONSIDERATION                                                                      3

ARTICLE III.          GRANT OF LICENSE AND COLLOCATION                                                   6

ARTICLE IV            INTENTIONALLY OMITTED                                                             10

ARTICLE V             TERM                                                                              10

ARTICLE VI            MAINTENANCE                                                                       11

ARTICLE VII.          AUDIT RIGHTS                                                                      11

ARTICLE VIII.         WARRANTIES                                                                        12

ARTICLE IX.           DEFAULT                                                                           12

ARTICLE X.            INDEMNIFICATION                                                                   13

ARTICLE XI.           LIMITATION OF LIABILITY                                                           14

ARTICLE XII.          INSURANCE                                                                         15

ARTICLE XIII.         TAXES                                                                             16

ARTICLE XIV.          NOTICE                                                                            16

ARTICLE XV.           CONFIDENTIALITY                                                                   17

ARTICLE XVI.          PROHIBITION ON IMPROPER PAYMENTS                                                  18

ARTICLE XVII.         FORCE MAJEURE; EMINENT DOMAIN                                                     19

ARTICLE XVIII.        SETTLEMENT OF DISPUTES                                                            19

ARTICLE XIX.          RULES OF CONSTRUCTION                                                             20

ARTICLE XX.           ASSIGNMENT                                                                        21

ARTICLE XXI.          ENTIRE AGREEMENT; AMENDMENT; EXECUTION                                            22
</Table>

                                       i

<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

                                    EXHIBITS

Exhibit A         Collocation Sites
Exhibit B         Operations Specifications

                                       ii
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

                      COLLOCATION AND MAINTENANCE AGREEMENT
                                 (METRO FIBERS)

         This COLLOCATION AND MAINTENANCE AGREEMENT (this "Agreement") is made,
as of the 26 day of April, 2002 (the "Effective Date") by and between METROMEDIA
FIBER NETWORK SERVICES, INC. ("Provider"), a Delaware corporation having its
principal office at 360 Hamilton Avenue, White Plains, New York 10601 and
WILLIAMS COMMUNICATIONS, LLC ("Customer"), a Delaware limited liability company,
having its principal office at One Technology Center, Tulsa, Oklahoma 74103.

                                   BACKGROUND

A. On this same date, the parties are entering a Fiber Lease Agreement and a
Fiber Lease Agreement No. 2 (together, "Fiber Agreements") pursuant to which
Customer agrees to lease from Provider certain fiber optic strands (the
"Customer Fibers"); and

B. Customer desires to have Provider operate and maintain the Customer Fibers
and Provider desires to provide such services to Customer on the terms and
conditions set forth herein; and

C. In addition to maintenance services, Customer desires to acquire from
Provider, and Provider desires to provide to Customer, certain collocation
rights and services for the Customer Fibers upon the terms and conditions set
forth in this Agreement; and

NOW, THEREFORE, in consideration of the mutual promises set forth below, and
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the Parties hereby agree as follows:

                             ARTICLE I. DEFINITIONS

Capitalized terms and phrases used in this Agreement shall have the following
meanings:

"ADDITIONAL SERVICES" shall have the definition set forth in Section 3.4.

"AFFILIATE" means, with respect to any entity, an entity controlling, controlled
by, or under common control with such entity by means of direct or indirect
majority equity ownership or otherwise. As used in this Agreement, "control"
shall mean possession, directly or indirectly, of the power to direct or cause
the direction of the management and policies of a person or entity, whether
through the ownership of voting securities, by contract or otherwise.

"BASIC SERVICES" shall have the definition set forth in Section 3.3.

"CLAIM" means any claim, action, dispute, or proceeding of any kind between
Customer (or any of its Affiliates, successors or assigns) and Provider (or any
of its Affiliates, successors, or assigns) and any other claim, transaction,
occurrence, loss, liability, expense or other matter arising out of, in
connection with, or in any way related to, the Collocation Sites and this
Agreement, including the Exhibits hereto.

                                       1
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

"COLLOCATION NOTICE" is defined in Section 3.5(a).

"COLLOCATION SITE" shall mean each location in which Customer is granted
collocation rights hereunder including POPs, regeneration and transmission
sites, central offices and commercial buildings. The initial Collocation Sites
are listed in Exhibit A (includes the specified number of racks listed for each
such location) and any provided in the future pursuant to Section 3.5(a).

"COSTS" means actual and directly related costs accumulated in accordance with
the established accounting procedure used by Provider or Customer or their
respective contractors or subcontractors, as the case may be, which costs
include the following: (a) labor costs, including wages, salaries, benefits and
overhead allocable to such labor costs (Customer's or Provider's overhead
allocation percentage shall not exceed the lesser of (i) the percentage such
party allocates to its internal projects or (ii) one hundred and thirty percent
(130%), and (b) other direct costs and out-of-pocket expenses on a pass-through
basis (e.g., equipment, materials, supplies, contract services, etc.).

"CUSTOMER EQUIPMENT" means optronic (opto-electrical), electronic, or optical
equipment, or materials, interconnection facilities, or other equipment owned,
possessed, or utilized by Customer.

"FACILITY OWNERS/LENDERS" means any entity (other than Provider): (a) owning any
portion of the Collocation Site or Customer Fibers or any property or security
interest therein, (b) leasing to Provider, or providing an IRU to Provider in,
any portion of the Customer Fibers, or (c) that is a lender (including any party
holding legal title or a security interest in Provider's network as a lessor or
a creditor) with respect to Provider or any Affiliates of Provider.

"FORCE MAJEURE EVENT" shall mean any event due to causes beyond the reasonable
control of a Party, including, but not limited to: act of God; fire; flood;
material shortage or unavailability not resulting from the responsible Party's
failure to timely place orders or take other necessary actions therefor,
government codes, ordinances, laws, rules, regulations, or restrictions; war or
civil disorder; provided that (i) a loss by a Party of employees (other than by
reason of one or more Force Majeure Events), (ii) strikes and other labor
actions involving a Party's own work force, (iii) the failure (other than by
reason of force majeure) of any subcontractor, supplier or transporter to
perform its obligations to a Party (except on account of insolvency) unless such
supplies or transportation or other services are generally unavailable in the
marketplace, and (iv) any increase a Party's costs, shall not in and of itself
constitute a Force Majeure Event; and provided that an act or omission shall not
be deemed to be "beyond its control" if committed, omitted or caused by such
Party, or its employees, officers, agents or affiliates, or by any corporation
or other business entity that holds a controlling interest in said Party,
whether held directly or indirectly.

"INSTALLATION DATE" is the first date the Collocation Site is ready and
available for installation of Customer Equipment.

"LEASE CLAIMS" shall have the meaning set forth in Section 11.4.

"PARTY" or "PARTIES" shall mean either Customer, Provider or both.

                                       2
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

"PERSON" shall mean an individual; association, partnership, corporation,
limited liability company or other legally recognized entity.

"POP" means a telecommunications point of presence and, unless the context
indicates otherwise, refers to a Provider-designated point of presence located
along the route of the Customer Fibers.

"RACK CREDIT" shall have the meaning set forth in Section 2.6 of this Agreement.

"RELEASED PARTY" means each of the following:

         (a) any Affiliates of the other party and any Facility Owners/Lenders;

         (b) any employee, officer, director, stockholder, partner, member, or
         trustee of the other party or of its Affiliates or Facility
         Owners/Lenders; or

         (c) assignees of the entities included in the above subparagraphs (a)
         or (b) and any employee, officer, director, stockholder, partner,
         member, or trustee of such assignees.

"TAKING" shall have the definition set forth in Section 17.2.

"TERM" means the term of this Agreement as defined in Section 5.1.

"UNDERLYING LANDLORD" means any entity (other than Provider) leasing to Provider
any Collocation Site.

                ARTICLE II. CONSIDERATION, FEES AND PAYMENT TERMS

2.1 CHARGES FOR MAINTENANCE. For each month during the Term, Customer shall pay
Provider a maintenance fee of [*****] per fiber mile, per month for the
maintenance services set forth in Article 6 of this Agreement. Invoices for such
maintenance services shall be issued monthly.

2.2 CHARGES FOR COLLOCATION.

    (a) BASIC SERVICES. Customer shall pay for the use of the rack space and
associated Basic Services (including power up to 30 amps per rack):

        (i) at Collocation Sites that service the Customer Fibers leased
        pursuant to the Fiber Lease Agreement at the rate of [****] per rack per
        month; and

        (ii) at Collocation Sites that service the Customer Fibers ordered
        pursuant to the Fiber Lease Agreement #2 at Provider's then current
        standard rates.

    (b) ADDITIONAL SERVICES. If Customer chooses to receive Additional Services,
it shall pay any and all (initial and continuing) costs reasonably incurred by
Provider in providing such Additional Services. Upon at least thirty (30) days'
notice to Customer, Provider may adjust recurring charges for the Additional
Services once each calendar year to equal its then-current standard charges.

                                       3
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

         (i) The current charge for additional racks (including up to 20 amps of
       power per rack) is [*****] per rack per month.

         (ii) The current monthly service charges for additional power are [***]
       per AC/amp or DC/amp (in excess of 20 combined amps per rack)

         (iii) Customer shall pay a non-recurring charge for initial
       installation of Additional Service at a POP, which charges are forth in
       the table below.

<Table>
<Caption>
Description of Charge                                       Nonrecurring Charge
---------------------                                       -------------------
<S>                                                         <C>
Initial Installation Charge per rack                            [******]
Per 10 AC or DC/amps (over combined 20) up                      [****] per amp
to 60 amps per rack total.
Charge for more than 60 amps per rack total                     [***]
</Table>

         (iv) Provider agrees that Customer may cross-connect with third parties
       at each Collocation Site. Provider will charge and Customer will pay the
       following charges for interconnecting within Provider's POP:

        o       A non-recurring charge of [*****] per cross-/interconnect
                (covers testing, cords...etc.)

        o       A monthly recurring charge of [****] for a single riser and
                [*****] for dual risers per 4 fibers.

         (c) ESCORTED ACCESS. Customer shall pay Provider's charges for escorted
access to Collocation Sites, which may include minimum call-out times, and
night, weekend, and holiday differentials or multipliers as set forth below:

        o       Monday-Friday, 8:00 am to 5:00 pm local (2 hour min)     [****]

        o       Monday-Friday, 5:01 pm to 7:59 am local (4 hour min)     [****]

        o       Saturday & Sunday (4 hour min)                           [****]

        o       Holidays (4 hour min)                                    [****]

         (d) Early Termination. Except as set forth in Section 3.2, Customer is
liable for Collocation Charges (a) for one year after the Installation Date at
each POP, and (b) for five years after the Installation Date at each non-POP. If
Customer elects to terminate use of any racks it shall do so by giving Provider
30 days prior written notice and paying a termination fee equal to such charges.

         (e) Ancillary Charges. Current ancillary charges related to changes of
the Basic Services or the Additional Services are set forth in the table below:

                                       4
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

<Table>
<Caption>
Ancillary Charges                                                           Charge Per Occurrence
-----------------                                                           ---------------------
<S>                                                                         <C>
Each change of Transmission Service Order (prior to spec being written)           [****]
Each change of Transmission Service Order (after spec written but before          [****]
install)
Each change of Transmission Service Order (after install)                         [************]
Order Cancellation of Additional Services (>/= 30 days from Additional            [****]
Services Ready Date)
Order Cancellation of Additional Services (< 30 days from Additional              [******]
Services Ready Date)
</Table>

All charges set forth in Subsections 2.2 (b), (c), (d) and (e) are subject to
change upon at least thirty (30) days' notice from Provider to Customer after
the first anniversary of the Effective Date. Notwithstanding anything to the
contrary in this Section 2.2, the charges for the services set forth in
Subsections 2.2 for to collocation relating to Customer Fibers ordered pursuant
to Lease Agreement #2 shall be at Provider's standard rates at the time of such
order.

2.3 METHOD OF PAYMENT. All payments to be made pursuant to this Agreement may be
made by check or draft of immediately available funds delivered to the address
designated in writing by the other Party (e.g., in a statement or invoice) or,
failing such designation, to the address for notice to such other Party provided
pursuant to Article XIV. Each Party shall make all payments in United States
currency.

2.4 TIME OF PAYMENT.

         (a) Recurring charges for maintenance services and collocation services
are invoiced in advance. Payments shall be prorated, as necessary, for the first
and last months such charges apply. Notwithstanding anything to the contrary in
this Agreement and regardless of whether Customer is ready to utilize the
collocation space in each of the Collocation Sites, the Collocation charges
shall begin to apply upon the Installation Date at the relevant site.

         (b) Provider shall issue invoices for any Additional Services after the
calendar month during which it provided such Additional Services, provided that
it may issue invoices for nonrecurring charges (including any Cost
reimbursement) based upon estimates of such charges and Customer shall pay such
invoices prior to performance of the work by Provider. Within thirty (30) days
of completion of the work, Provider shall invoice Customer for any Costs of such
work exceeding the estimate, or if the estimate exceeds the actual Costs,
Provider shall refund the Customer the difference.

         (c) Except as otherwise set forth in this Agreement, all amounts are
payable within thirty (30) calendar days of the invoice delivery date, as
determined by Section 14.2. Notwithstanding anything to the contrary contained
herein, Customer shall pay the maintenance and collocation fees during the term
of that certain Monthly Netting Agreement executed by the Parties on October 20,
2002, in accordance with the provisions of such Monthly Netting Agreement.

2.5 NO OTHER FEES. Except as otherwise set forth in this Agreement, neither
party shall charge the other party any maintenance, right-of-way, conduit
occupancy, or other recurring charges.

                                       5
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

2.6 RACK CREDITS. Notwithstanding anything contained herein to the contrary, in
consideration for the lease payments paid by Customer under the Fiber Lease
Agreement, Customer shall receive [*****] RACK CREDITS ("Rack Credits").

         (a) Each Rack Credit entitles Customer to the right to the use of one
rack for one month together with associated Basic Services (including power up
to 30 amps per rack) in all Collocation Sites other than MFN Data Centers or
PAIX locations.

         (b) At MFN Data Centers, Rack Credits shall be applied up to [********]
Rack Credits per month per Collocation Site and will be debited at the rate of
[*******] rack credits per [*******] rack utilized by Customer (for a maximum of
[*] racks per MFN Data Center), and such Rack Credits shall not include any
services within such Collocation Sites for which Customer shall pay Provider's
then current rates.

         (c) Customer leases equipment rack space and power from PAIX.net, Inc.,
a subsidiary of Provider ("PAIX), pursuant to the PAIX Telecommunications
Carrier License Agreement dated May 15, 2000. Provider agrees to cause PAIX to
apply the Rack Credits a maximum of [********] racks per PAIX facility (Telco
and IP) used by Lessee. Such Rack Credits shall not include any services within
PAIX collocation facilities for which Customer shall pay pursuant to its
agreement with PAIX.

         (d) At such time as Customer utilizes all such Rack Credits, Customer
shall thereafter pay cash for the use of such racks together with associated
Basic Services at the rates set forth in Section 2.2(a) above.

                  ARTICLE III. GRANT OF LICENSE AND COLLOCATION

3.1 GRANT OF LICENSE.

         (a) Customer's rights under this Agreement are solely contractual,
granting Customer an exclusive license to locate, install, maintain and operate
Customer Equipment at each Collocation Site, but only as permitted by this
Agreement and only to the extent expressly set forth in this Agreement or an
accepted order for collocation services. No use of a Collocation Site required
or permitted under this Agreement shall create or vest in Customer any
easements, leasehold interests, or other ownership or property rights of any
nature in Provider's real or personal property. Customer shall provide,
maintain, and for all purposes be solely responsible for all Customer Equipment
at Collocation Sites.

         (b) Customer shall have the exclusive right to use the rack space
allocated to Customer in each Collocation Site for any lawful purpose. Provider
shall have no right to use such space during the Term except in the event of a
Customer default and subsequent termination of this Agreement.

         (c) Customer's right to use rack space set forth in Exhibit A is
considered by the parties to be a prepaid license for a period equal to the
number of months until all of the Rack Credits set forth in Section 2.6 have
been utilized by Customer.

         (d) In addition to the restrictions set forth in Article XX, Customer
shall not, directly or indirectly, convey any interest, sublicense or sublease
in the Collocation Site or any racks at such site

                                       6
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

(including Customer's right to occupy the Collocation Site) to any other person,
firm or entity, without the prior written consent of Lessor.

3.2 COLLOCATION SITES. Provider agrees to provide and Customer agrees to pay for
the Collocation Sites and corresponding number of racks identified in Exhibit A
in each of Provider's Collocation Sites. From time to time, Customer may order
additional Basic Services and Additional Services at Provider's Collocation
Sites in accordance with Section 3.5(a). If accepted by Provider, the parties
will execute a new order for collocation and all such orders are automatically
incorporated by reference.

3.3 BASIC SERVICES. At each Collocation Site, Provider will provide to Customer
the number of racks specified in Exhibit A, plus HVAC, and 30 amps of negative
48v DC power per rack (collectively, the "Basic Services"). A rack space shall
be adequate to contain a rack (measuring 26 inches (width) x 24 inches (depth) x
78 or 84 inches (height)). The total linear inches for Customer rack space
within each location shall not exceed the sum of the number of rack spaces for
such location multiplied by 26 inches. To the extent Provider has additional
available and uncommitted collocation space and power at the Collocation Sites,
Customer may order additional Basic Services. Customer shall use the standard
Provider procedures for ordering such additional Basic Services.

3.4 ADDITIONAL SERVICES. Customer may request in writing separate caged access,
installation services, AC power or additional DC power, additional back-up
power, technical assistance, additional space or racks, cross-connects, or
additional HVAC (collectively referred to as the "Additional Services") at any
Collocation Site. Within thirty (30) business days after receiving such written
request, Provider shall notify Customer whether the Additional Services are
available and, if they are, Provider's standard rates for the Additional
Services as set forth in Section 2.2(b). Customer shall provide written notice
to Provider confirming its request for such Additional Services at the quoted
rates prior to Provider providing such Additional Services. If upgrades or
expansions to a Collocation Site or its facilities are necessary to accommodate
Customer's request, Provider may charge the entire Costs of such upgrades or
expansions to Customer to be paid in advance.

3.5 DELIVERY AND INSTALLATION.

         (a) No later than sixty (60) days prior to Customer's desired
Installation Date at any Collocation Site, Customer shall provide to Provider
the "Collocation Notice." The Collocation Notice shall include notice of
Customer's desire to collocate in a particular Collocation Site, a copy of
Customer's construction design drawings and installation schedule. The
Collocation Notice shall also include: (a) Customer's requested installation
date(s); (b) any excess cable storage requirements; (c) identification of all
Customer Equipment to be installed; (d) a diagram of the desired location of the
Customer Equipment; (e) the space, power, environmental and other requirements
for the Customer Equipment; (f) all other information reasonably required by
Provider. Within thirty (30) business days of receiving the Collocation Notice,
Provider shall respond with its acceptance or rejection.

         (b) Customer shall, at its expense, cause Customer Equipment to be
delivered, installed, and maintained in a safe condition and meeting or
exceeding the standards of Provider. Provider shall allow Customer reasonable
access to each Collocation Site for purposes of installing Customer Equipment,
provided that, if a Collocation Site is not ready for installation of equipment
other than security, alarm, HVAC, power, back-up power or other common systems
on such date, Provider shall allow such access

                                       7
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

within five (5) days of the first date such Collocation Site is ready for such
installation. Provider shall provide Customer with at least thirty (30) days
notice prior to the date it estimates each Collocation Site will be ready for
installation of Customer Equipment.

3.6 ALARMS.

         (a) Provider shall continuously monitor Collocation Site security,
environmental, and power alarms at one or more manned monitoring centers. At
Customer's request, Provider shall establish procedures to allow Customer, at
Customer's expense, to share or (at Provider's option) receive indirectly
security and environmental alarm information where technically feasible.

         (b) Each Party shall promptly notify the other of any matters
pertaining to any damage or impending damage to or loss of the use of
Collocation Site or surrounding premises that are known to it and that could
reasonably be expected to adversely affect the Collocation Site.

3.7 COLLOCATION SITE MAINTENANCE. Customer shall provide all maintenance and
repair of Customer Equipment. Any improvement, modification, addition to,
relocation, or removal of Customer Equipment, shall be subject to Provider's
prior review and written approval. Customer shall pay the cost of such
improvement, modification, addition to, relocation, or removal of, the Customer
Equipment. Provider's approval will not be unreasonably withheld. Provider's
maintenance responsibility shall be limited to the demarcation point and the
associated cross connect at that point.

3.8 USE OF CUSTOMER EQUIPMENT.

         (a) POWER USE. Customer shall not install any electrical or other
equipment that overloads any electrical paneling, circuitry, or wiring.

         (b) STANDARDS. Customer shall ensure that Customer Equipment is
installed, operated, and maintained to meet or exceed any reasonable
requirements of Provider, any requirements of Provider's building management or
insurance underwriters, and any applicable local, state and federal codes and
public health and safety laws and regulations (including fire regulations and
the National Electric Code).

         (c) INTERVENTION. If any part of the Customer Fibers or Customer
Equipment is not placed and maintained in accordance with the terms and
conditions of this Agreement and Customer fails to correct the violation within
(i) ten (10) days if the violation creates a life safety hazard, or (ii) thirty
(30) days for any other violation, each from receipt of written notice thereof
from Provider, then Provider may, at its option, without further notice to
Customer, correct the deficiency at Customer's expense without liability (except
to the extent the Agreement permits recovery for Provider's gross negligence)
for damages to the fiber, Customer Equipment or for any interruption of
Customer's services. As soon as practicable thereafter, Provider shall advise
Customer in writing of the work performed or the action taken. Customer shall
reimburse Provider for all Costs reasonably incurred by Provider associated with
any work or action performed by Provider pursuant hereto.

         (d) THREAT TO PERSONS OR PROPERTY. If Provider determines that
Customer's actions or failure to fulfill an obligation of this Agreement, or its
Customer Equipment poses an immediate threat to the safety of Provider's
employees or the public, interferes with the performance of Provider's service

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obligations, or poses an immediate threat to the physical integrity of
Provider's facilities, Provider may perform such work and/or take such action
that it deems necessary without notice to Customer and without subjecting itself
to any liability (except to the extent the Agreement permits recovery for
Provider's gross negligence) for damage to the fiber, Customer Equipment or for
any interruption of Customer's services. As soon as practicable thereafter,
Provider shall advise Customer in writing of the work performed or the action
taken. Customer shall reimburse Provider for all expenses reasonably incurred by
Provider associated with any work or action performed by Provider pursuant
hereto. Customer shall remit payment to Provider within thirty (30) calendar
days from its receipt of Provider's invoice therefor.

3.9 ACCESS TO COLLOCATION SITE. Provider shall provide Customer with escorted
twenty-four hour access to Customer's assigned racks and, as reasonably
necessary, other portions of Provider's common space. Customer agrees to pay the
fees set forth in Section 2.2(d) for escorted access. To obtain such access,
Customer shall provide Provider with reasonable advance notice and Provider
shall provide escorted access. Provider shall use reasonable efforts to respond
to emergency requests for such access.

         (a) NOTICE. Customer shall notify Provider Network Operations Center
prior to entering a Collocation Site and shall comply with any reasonable
Provider notice procedures.

         (b) SECURITY. Customer shall abide by Provider's reasonable security
requirements. When deemed appropriate by Provider, Customer employees,
customers, or representatives shall be issued passes or visitor identification
cards which must be presented upon request before entry to Collocation Sites and
surrendered upon demand or upon termination of the Agreement. Such passes or
other identification shall be issued only to persons meeting any reasonable
security criteria applicable at the relevant Collocation Site for such purpose.
Nothing in this Subsection shall be construed as preventing Customer from having
twenty-four hour escorted access to Collocation Sites.

         (c) RIGHT TO TERMINATE INDIVIDUAL'S ACCESS. Notwithstanding any other
provision of this Agreement, Provider shall, without threat of liability, have
the right to immediately terminate the right of access of any Customer personnel
or representative should it determine in its sole discretion for any lawful
reason that termination of such access is in its best interest. Provider shall
promptly notify Customer of any such termination, and Customer shall have a
reasonable opportunity to demonstrate that the terminated rights of access
should be reinstated. Any termination of a specific individual's access shall
remain in effect pending Provider's final determination as to the advisability
of such reinstatement.

         (d) REMOVAL OF CUSTOMER EQUIPMENT. Within sixty (60) days after the end
of the Term or Customer's abandonment of any collocation arrangement at a
Collocation Site, Customer shall remove all Customer Equipment from the System
or any other Provider facilities at Customer's sole cost under Provider's
supervision. Customer shall provide Provider with at least sixty (60) days'
notice prior to such removal. If Customer fails to remove the same within said
sixty-day period, Provider shall either:

        (i) remove Customer's Equipment and issue an invoice to Customer for the
     cost of removal and storage; or

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        (ii) notify Customer that Provider elects to take ownership of such
    abandoned Customer Equipment, in which case Customer shall execute a bill of
    sale or other document evidencing Provider's title to such Customer
    Equipment.

3.10 NO RESTRICTIONS. Provider's right to maintain and operate its facilities in
such a manner as will best enable it to fulfill its own service requirements is
in no manner limited by this Agreement, except as specifically set forth in this
Agreement.

3.11 INSPECTIONS. Provider reserves the right to make periodic inspections of
any part of the Collocation Sites; provided that Customer shall have the right
to have one or more of its employees or representatives present during the time
of any such inspection. Provider shall give Customer advance notice of such
inspections, except in those instances where Provider determines that safety
considerations justify the need for such an inspection without the delay of
providing notice. The making of periodic inspections or the failure to do so
shall not operate to impose upon Provider any liability of any kind whatsoever
nor relieve Customer of any responsibility, obligation, or liability allocated
to it in this Agreement.

3.12 LIENS AND ENCUMBRANCES. Customer shall not have the power, authority or
right to create and shall not permit any lien or encumbrance, including, without
limitation, tax liens, mechanics' liens, or other liens or encumbrances with
respect to work performed, in connection with the installation, repair,
maintenance or operation of its Customer Equipment or other property installed
within the Collocation Site.

3.13 SUBORDINATION. Customer's rights under this Agreement shall be totally
subordinate to any bona fide mortgages, loans, deeds of trust, or any other
borrowing upon the real or personal property which may be incurred by Provider.
Customer shall sign any such reasonable documents as are necessary to satisfy
any lender, private or institutional, to reflect said subordination.

3.14 INDEPENDENT PARTIES. The presence of a Provider or Customer employee or
representative (as an inspector or otherwise) while an employee or
representative of the other party is at the Collocation Site or performing work
pursuant to this Agreement shall not make either party liable for the actions of
the other party and shall not be deemed to waive the responsibility of either
party to perform its obligations in a safe and workmanlike manner.

                        ARTICLE IV. INTENTIONALLY OMITTED

                                 ARTICLE V. TERM

5.1 TERM. The Term of this Agreement begins on the Effective Date and expires
co-terminously with the latest expiring Fiber Agreement.

5.2 EFFECT OF TERMINATION. No termination of this Agreement shall affect the
rights or obligations of any Party hereto:

         (a) with respect to any payment hereunder for services rendered prior
to the date of termination;

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         (b) pursuant to Articles VII (Audit Rights), X (Indemnification), XI
(Limitation of Liability), XII (Insurance), XIII (Taxes), XV (Confidentiality),
XVI (Prohibition on Improper Payments), XVIII (Settlement of Disputes), or XIX
(Rules of Construction) or Sections 8.2 (Disclaimer of Warranty) or 8.3 (No
Third-Party Warranties); or

         (c) pursuant to other provisions of this Agreement that, by their sense
and context, are intended to survive termination of this Agreement.

                     ARTICLE VI. CUSTOMER FIBER MAINTENANCE

6.1 MAINTENANCE SERVICES. During the Term of this Agreement, Provider shall
provide, or cause to be provided by contractors selected by Provider, emergency
and non-emergency maintenance and repair of the Customer Fibers all pursuant to
the operations specifications set forth in Exhibit B. Provider, at Customer's
sole expense and at Provider's or its subcontractor's then prevailing rates,
shall perform maintenance and repair necessitated by Customer's negligence or
willful misconduct or Customer's elective maintenance or repair requests.

6.2 MAINTENANCE OF CUSTOMER'S EQUIPMENT EXCLUDED. Provider shall have no
obligation under this Agreement to maintain, repair or replace Customer's
Equipment.

6.3 NO UNAUTHORIZED ACCESS TO SYSTEM. Customer shall not access the Customer
Fibers (other than pursuant to this Agreement).

6.4 RELOCATION. If Provider is required to relocate the Customer Fibers,
Provider shall give Customer not less than 180 calendar days' prior written
notice (unless Provider has received less than 180 days' notice, in which case
Provider shall give notice to Customer as promptly as reasonably practicable
after Provider receives such notice or determines that a relocation is
necessary) of such relocation. Provider shall use commercially reasonable
efforts to arrange for such relocation as promptly as practicable. Provider
shall provide Customer with updated as-built drawings with respect to any
relocated portion of the relocated System not later than 180 calendar days
following the completion of such relocation. Provider shall perform any
relocation such that: (a) the relocated facilities shall be constructed and
tested in accordance with the specifications and requirements set forth in the
Fiber Lease Agreement, including the applicable Exhibits; (b) the relocation
shall not result in a materially adverse change to the operations, performance,
or interconnections of Customer, or the end points or meet points of the
Customer Fibers; (c) the relocation maintains diversity of Customer Fibers, if
diversity existed prior to the relocation; and (d) the relocation shall not
unreasonably interrupt service on the Customer Fibers. Customer shall receive at
least twenty-one (21) calendar days advance notice of any interruption in
service of Customer Fibers which will be caused by a relocation, and such
relocation shall be coordinated such that any interruption shall only occur
between the hours of 12 midnight and 6 A.M. local time on Saturdays and Sundays.

                            ARTICLE VII. AUDIT RIGHTS

Each party shall keep such books and records (which shall be maintained on a
consistent basis and substantially in accordance with generally accepted
accounting principles) as shall readily disclose the

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basis for any charges (except charges fixed in advance by this Agreement or by
separate agreement of the parties) or credits, ordinary or extraordinary, billed
or due to the other party under this Agreement and shall make them available for
examination, audit, and reproduction by the other party and its agents for a
period of one year after such charge or credit is billed or due. To the extent a
party seeks reimbursement of out-of-pocket costs or services provided on a
per-hour basis, it shall provide reasonable supporting documentation to the
other party.

                            ARTICLE VIII. WARRANTIES

8.1 AGREEMENT VALIDITY. Each party represents and warrants that: (a) it has the
full right and authority to enter into, execute, deliver and perform its
obligations under this Agreement; (b) it has taken all requisite corporate
action to approve the execution, delivery and performance of this Agreement; (c)
this Agreement constitutes a legal, valid and binding obligation enforceable
against such party in accordance with its terms; (d) its execution of and
performance under this Agreement shall not violate any applicable existing
regulations, rules, statutes or court orders of any local, state or federal
government agency, court or body; and (e) it has the right pursuant to such
party's Right-of-Way Authorizations to grant the rights to the other party as
set forth in this Agreement.

8.2 DISCLAIMER OF WARRANTY. EXCEPT AS SPECIFICALLY SET FORTH IN THIS AGREEMENT,
PROVIDER MAKES NO WARRANTY TO CUSTOMER OR ANY OTHER PERSON OR ENTITY, WHETHER
EXPRESS, IMPLIED, OR STATUTORY, AS TO THE DESCRIPTION, QUALITY, MERCHANTABILITY,
COMPLETENESS OR FITNESS FOR ANY PURPOSE OF ANY FIBERS OR ANY SERVICE PROVIDED
HEREUNDER OR DESCRIBED HEREIN, OR AS TO ANY OTHER MATTER, ALL OF WHICH
WARRANTIES ARE HEREBY EXCLUDED AND DISCLAIMED.

8.3 NO THIRD-PARTY WARRANTIES. NO FACILITY OWNERS/LENDERS HAVE MADE ANY
REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, TO CUSTOMER
CONCERNING PROVIDER, CUSTOMER FIBERS OR AS TO ANY OF THE MATTERS SET FORTH IN
SECTIONS 8.1 OR 8.2. NO CUSTOMER LENDERS HAVE MADE ANY REPRESENTATION OR
WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, TO PROVIDER CONCERNING CUSTOMER,
CUSTOMER FIBERS OR AS TO ANY OF THE MATTERS SET FORTH IN THIS AGREEMENT.

                               ARTICLE IX. DEFAULT

9.1 TERMINATION UPON DEFAULT. Either party, upon written notice to the other
party after the other party's default and the other party's failure to cure any
default in the performance of any material obligation hereunder prior to the end
of the applicable cure period, may terminate this Agreement as herein provided,
provided that at the time of termination such default remains uncured.

9.2 SPECIFIC DEFAULT EVENTS. Events of default shall include but not be limited
to: (a) the making of a general assignment for the benefit of the defaulting
party's creditors; (b) the filing of a voluntary petition in bankruptcy or the
filing of a petition in bankruptcy or other insolvency protection against the
defaulting party which is not dismissed within 90 calendar days thereafter; (c)
the filing by the defaulting party of any petition or answer seeking, consenting
to, or acquiescing in reorganization, arrangement,

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adjustment, composition, liquidation, dissolution, or similar relief; (d) any
violation by Customer of the restrictions set forth in Article 20.

9.3 CURE PERIOD. The cure period applicable to Section 9.1 shall be:

         (a) with respect to a default in payment, the period ending ten (10)
business days after a written notice of such default is given;

         (b) with respect to any other default, the period ending 30 calendar
days after a written notice of such default is given, provided, however, that if
such default cannot with reasonable diligence be cured within such 30-day
period, and such other party has commenced to effect a cure immediately upon
receipt of such notice, and diligently pursues such cure, then such cure period
will be extended for a period reasonably required to cure such default but in no
event more than an additional 30 calendar days.

9.4 FAILURE TO CURE. Upon the failure by the defaulting party to timely cure any
such default after notice thereof from the other party, the other party may take
such action as it determines, in its sole discretion, to be necessary to correct
the default, and pursue any legal remedies it may have under this Agreement,
applicable law, or principles of equity relating to such breach.

9.5 WAIVER OF SPECIFIC DEFAULTS. Any event of default by the defaulting party
may be waived under the terms of this Agreement at the other party's option. Any
such waiver shall be in writing.

9.6 DISPUTED AMOUNTS. Notwithstanding the other provisions of this Article,
failure to pay an amount subject to a bona fide dispute shall not be an event of
default to the extent the disputed amount is (a) less than $100,000 or (b) paid
into an escrow account of a nationally chartered domestic bank to be established
by the parties within thirty (30) days of the Effective Date of this Agreement.

                           ARTICLE X. INDEMNIFICATION

10.1 INDEMNITY. Each party shall indemnify, defend, protect and hold harmless
the other party, its employees, officers, directors, agents, shareholders,
affiliates, Facility Owners/Lenders, and other parties to Right-of-Way
Authorizations that are entitled to indemnity by such indemnifying party (the
"Indemnitor"), from and against, and assumes liability for:

         (a) Any injury, loss or damage to any person, tangible property or
facilities of any person or entity (including reasonable attorneys' fees and
costs), to the extent arising out of or resulting from the acts or omissions,
negligent or otherwise, of the indemnifying party, its officers, employees,
servants, affiliates, agents or contractors in connection with its performance
under this Agreement; and

         (b) Any claims, liabilities or damages arising out of any violation by
the indemnifying party of regulations, rules, statutes or court orders of any
local, state or federal governmental agency, court or body in connection with
its performance under this Agreement.

10.2 NO LIMITATION ON CLAIMS AGAINST OTHER PARTIES. Except as set forth herein,
and subject to the terms of any underlying agreements between Provider and any
third person, nothing contained herein

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shall operate as a limitation on the right of either party hereto to bring an
action for damages against any third person, including indirect, special or
consequential damages, based on any acts or omissions of such third person as
such acts or omissions may affect the construction, operation or use of the
Customer Fibers; provided, however, that each party hereto shall assign such
rights of claims, execute such documents and do whatever else may be reasonably
necessary to enable the other party to pursue any such action against such third
person.

10.3 NOTICE. Provider and Customer agree to promptly provide each other with
notice of any claim which may result in an indemnification obligation hereunder.
The Indemnitor may defend such claim with counsel of its own choosing provided
that no settlement or compromise of any such claim shall occur without the
consent of the other Party, which consent shall not be unreasonably withheld or
delayed.

10.4 MATERIAL AND CONTINUING OBLIGATION. Each Party's obligation to indemnify,
defend, protect, and save the other Party harmless is a material obligation to
the continuing performance of the other Party's obligations hereunder.

                       ARTICLE XI. LIMITATION OF LIABILITY

11.1 RESTRICTION ON TYPES OF LIABILITY. NOTWITHSTANDING ANY PROVISION OF THIS
AGREEMENT TO THE CONTRARY, IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE OTHER
PARTY FOR ANY SPECIAL, INCIDENTAL, INDIRECT, PUNITIVE, RELIANCE OR CONSEQUENTIAL
DAMAGES, WHETHER FORESEEABLE OR NOT, ARISING OUT OF, OR IN CONNECTION WITH THIS
AGREEMENT, IN TORT, BREACH OF CONTRACT, BREACH OF WARRANTY, STRICT LIABILITY OR
ANY OTHER CAUSE OF ACTION, INCLUDING DAMAGE OR LOSS OF PROPERTY OR EQUIPMENT,
LOSS OF PROFITS OR REVENUE, COST OF CAPITAL, COST OF REPLACEMENT SERVICES, OR
CLAIMS OF CUSTOMERS, WHETHER OCCASIONED BY ANY REPAIR OR MAINTENANCE PERFORMED
BY, OR FAILED TO BE PERFORMED BY, THE FIRST PARTY OR ANY OTHER CAUSE WHATSOEVER.

11.2 NO RECOURSE AGAINST RELEASED PARTIES. Neither party shall have any recourse
of any kind against any Released Party or any assets of a Released Party under
this Agreement, it being expressly agreed and understood that no liability
whatever shall attach to or be incurred by any Released Party under or by reason
of this Agreement or any other instrument, arrangement or understanding related
to Customer Fibers or Collocation Sites. Each party waives all such recourse to
the extent set forth in this Section on behalf of its successors, assigns, and
any entity claiming by, through, or under such party.

11.3 NO PERSONAL LIABILITY. Each action or claim against any party arising under
or relating to this Agreement shall be made only against such party as a
corporation, and any liability relating thereto shall be enforceable only
against the corporate assets of such party. No party shall seek to pierce the
corporate veil or otherwise seek to impose any liability relating to, or arising
from, this Agreement against any shareholder, employee, officer, director or
agent of the other party. Each of such persons is an intended beneficiary of the
mutual promises set forth in this Section and shall be entitled to enforce the
obligations or provisions of this Section.

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11.4 PURSUIT OF ACTIONS AGAINST UNDERLYING LANDLORDS. Notwithstanding the
foregoing provisions of this Article, and only to the extent Provider is
required under the terms and provisions of any underlying lease or agreement to
indemnify an Underlying Landlord from and against any and all claims, suits,
judgments, liabilities, losses and expenses (hereinafter "Lease Claims") arising
out of service interruption, cessation, unreliability of or damage to the
Collocation Site, regardless of whether such Lease Claims arise from the sole or
partial negligence, willful misconduct or other action or inaction of such
Underlying Landlord, Customer hereby releases such Underlying Landlord, and
hereby waives, all Lease Claims arising out of service interruption, cessation,
unreliability of or damage to the Collocation Site regardless of whether such
claims, suits, judgments, liabilities, losses or expenses arise from the sole or
partial negligence, willful misconduct or other action or inaction, of such
Underlying Landlord. Customer shall notify Provider in writing before pursuing
any such Lease Claim against an Underlying Landlord and such notification shall
make specific reference to this provision of the Agreement, and Provider shall
respond in writing within sixty (60) days after receipt of such notification as
to whether or not the terms of such underlying lease require Customer to release
and waive such Lease Claim against the Underlying Landlord in question.

                             ARTICLE XII. INSURANCE

12.1 OBLIGATION TO OBTAIN. During the Term of this Agreement, the parties shall
each obtain and maintain not less than the following insurance:

         (a) Commercial General Liability Insurance, including coverage for
sudden and accidental pollution legal liability, with a combined single limit of
$10,000,000 for bodily injury and property damage per occurrence and in the
aggregate; provided that such coverage may be obtained through a combination of
specific and umbrella or excess liability policies.

         (b) Worker's Compensation Insurance in amounts required by applicable
law and Employers Liability Insurance with limits not less than $1,000,000 each
accident. If a party is to perform work in Nevada, North Dakota, Ohio,
Washington, Wyoming, or West Virginia, the party shall participate in the
appropriate state fund(s) to cover all eligible employees and provide a stop gap
endorsement.

         (c) Automobile Liability Insurance with a combined single limit of
$2,000,000 for bodily injury and property damage per occurrence, to include
coverage for all owned, non-owned, and hired vehicles; provided that such
coverage may be obtained through a combination of specific and umbrella or
excess liability policies.

If the Landlord imposes more stringent insurance requirements pursuant to the
relevant lease (as it may be modified from time to time), Customer shall
promptly comply with the Landlord's requirements, after receiving written notice
of such requirements. Provider shall, upon Customer's request, provide a copy of
the relevant provisions of the lease to Customer, to the extent such disclosure
is not prohibited by the terms of the lease.

The limits set forth in this Section are minimum limits and shall not be
construed to limit the liability of either party.

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12.2 POLICY REQUIREMENTS. Each party shall obtain and maintain the insurance
policies required above with companies rated A- or better by Best's Key Rating
Guide or with a similar rating by another generally recognized rating agency.
The other party, its Affiliates, officers, directors, and employees, and any
other party entitled to indemnification hereunder shall be named as additional
insureds to the extent of such indemnification. Each party shall provide the
other party with an insurance certificate confirming compliance with the
insurance requirements of this Article. The insurance certificate shall indicate
that the other party shall be notified not less than 30 calendar days prior to
any cancellation or material change in coverage. If either party provides any of
the foregoing coverages through a claims made policy basis, that party shall
cause such policy or policies to be maintained for at least three years beyond
the expiration of this Agreement.

12.3 WAIVER OF SUBROGATION. The parties shall each obtain from the insurance
companies providing the coverages required by this Agreement a waiver of all
rights of subrogation or recovery in favor of the other party and, as
applicable, its members, managers, shareholders, Affiliates, assignees,
officers, directors, and employees or any other party entitled to indemnity
under this Agreement to the extent of such indemnity.

12.4 BLANKET POLICIES; SELF-INSURANCE. Nothing in this Agreement shall be
construed to prevent either party from satisfying its insurance obligations
pursuant to this Agreement (a) under a blanket policy or policies of insurance
that meet or exceed the requirements of this Article or (b) with respect to the
insurance required in Sections 12.1(b) and (c), with the consent of the other
party, which consent shall not be unreasonably withheld, self-insurance.

                               ARTICLE XIII. TAXES

13.1 TAXES. Provider shall be responsible for all ad valorem property taxes
relating to portions of its network, excluding the Customer Fibers, as well as
any taxes required for the provision of the maintenance and collocation services
under this Agreement.

13.2 COOPERATION. Provider and Customer acknowledge and agree that it is their
mutual objective and intent to minimize to the extent feasible all taxes and
that they will cooperate with each other and coordinate their mutual efforts to
achieve such objectives in accordance with the provisions of this Article. The
Parties shall cooperate in any contest of any taxes or fees and in making tax
related reports and filings, so as to avoid, to the extent reasonably possible,
prejudicing the interests of the other Party.

                               ARTICLE XIV. NOTICE

14.1 NOTICE ADDRESSES. Unless otherwise provided in this Agreement, all notices
and communications concerning this Agreement shall be in writing and addressed
to the other Party as follows:

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If to Provider:            Metromedia Fiber National Network, Inc.
                           Attn: President
                           360 Hamilton Avenue
                           White Plains, New York 10601
                           Facsimile:  (914) 421-7550

with a copy to:                  Metromedia Fiber National Network, Inc.
                           Attn: General Counsel
                           One North Lexington Avenue
                           White Plains, New York 10601
                           Facsimile:  (914) 421-6793

If to Customer:            Williams Communications, LLC
                           Attn: Contract Management
                           One Technology  Center, TC-6H
                           Tulsa, Oklahoma 74103
                           Facsimile:  (918) 547-0460

with a copy to:            Williams Communications, LLC
                           Attn:   IRU Administration
                           One Technology Center, TC-8A
                           Tulsa, OK 74103
                           Facsimile:  (918) 547-2991

and                        Williams Communications, LLC
                           Attn: General Counsel
                           One Technology Center, TC-15A
                           Tulsa, Oklahoma 7415
                           Facsimile:  (918) 547-2630

or at such other address as may be designated in writing to the other Party.

14.2 NOTICE AND INVOICE DELIVERY. Unless otherwise provided herein, notices and
invoices shall be: (a) hand delivered, (b) sent by registered or certified U.S.
Mail, postage prepaid, (c) by commercial overnight delivery service, or (d)
transmitted by facsimile, and shall be deemed served or delivered to the
addressee or its office when received at the address for notice specified above
when hand delivered, three (3) United States Postal Service business days after
deposit in the mail when sent by U.S. mail on the day after being sent when sent
by overnight delivery service, and upon confirmation of sending when sent by
facsimile. .

                           ARTICLE XV. CONFIDENTIALITY

15.1 CONFIDENTIALITY OBLIGATION. If either Party provides confidential
information to the other or, if in the course of performing under this Agreement
or negotiating this Agreement a Party learns confidential information regarding
the facilities or plans of the other, the receiving Party shall (a) protect the
confidential information from disclosure to third parties with the same degree
of care accorded its

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own confidential and proprietary information, but in any case with at least
reasonable care and (b) refrain from using such confidential information except
in negotiating or performing under this Agreement. Notwithstanding the above, a
Party may provide such confidential information to its directors, officers,
members, managers, employees, agents, and contractors, consultants
("Representatives"), Affiliates, contractors, financial institutions, lenders,
Underlying Landlords, potential assignees (who are bound by a written agreement
restricting use and disclosure of confidential information), and Representatives
of Affiliates, in each case whose access is reasonably necessary. Each such
recipient of confidential information shall be informed by the Party disclosing
confidential information of its confidential nature, and shall be directed to
treat such information confidentially and shall agree to abide by these
provisions. In any event, each Party shall be liable (with respect to the other
Party) for any breach of this provision by any entity to whom that Party
discloses confidential information. The terms of this Agreement (but not its
execution or existence) shall be considered confidential information for
purposes of this Article, except as set forth in Section 15.3. The obligations
set forth in this Section shall survive expiration or termination of this
Agreement for a period of two (2) years, except that, with respect to any
confidential information designated by the disclosing Party as a trade secret,
and entitled to protection as such, the obligations set forth in this Section
shall survive such expiration or termination indefinitely.

15.2 PERMITTED DISCLOSURES. Notwithstanding any other provision herein, neither
Provider nor Customer shall be required to hold confidential any information
that:

         (a) becomes publicly available other than through the recipient;

         (b) is required to be disclosed by a governmental, regulatory
authority, or judicial order, rule, or regulation or proceedings with respect to
this Agreement or a Party's obligations as a publicly held company, provided
that a Party subject to such requirement shall promptly notify the other Party
of such requirement;

         (c) is independently developed by the disclosing Party;

         (d) becomes available to the disclosing Party without restriction from
a third party;

         (e) to the extent disclosure by the receiving Party as required by
applicable law or regulation.

15.3 GOODWILL AND PUBLICITY. Neither Party shall use the name, trade name,
service mark, or trademark of the other in any promotional or advertising
material without the prior written consent of the other. Provided each Party
consents, the Parties shall coordinate and cooperate with each other when making
public announcements related to the terms of this Agreement and each Party shall
have the right to promptly review, comment upon, and approve any publicity
materials, press releases, or other public statements by the other Party that
refer to, or that describe any aspect of, this Agreement.

                  ARTICLE XVI. PROHIBITION ON IMPROPER PAYMENTS

Neither Party shall use any funds received under this Agreement for illegal or
otherwise "improper" purposes. Neither Party shall pay any commission, fees or
rebates to any employee of the other Party. If either Party has reasonable cause
to believe that one of the provisions in this Article has been violated,

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it, or its representative, may audit the books and records of the other Party
for the sole purpose of establishing compliance with such provisions, to the
extent reasonably necessary.

                   ARTICLE XVII. FORCE MAJEURE; EMINENT DOMAIN

17.1 EXCUSED PERFORMANCE. Neither Provider nor Customer shall be in default
under this Agreement with respect to any delay in its performance (other than
the payment of monetary amounts due under this Agreement) caused by any Force
Majeure Event. The Party claiming relief under this Article shall promptly
notify the other in writing of the existence of the Force Majeure Event relied
on, the expected duration of the Force Majeure Event, and the cessation or
termination of the Force Majeure Event. The Party claiming relief under this
Article shall exercise commercially reasonable efforts to minimize the time for
any such delay.

17.2 EMINENT DOMAIN. Should any portion of a Collocation Site or the Customer
Fibers be acquired by eminent domain, nationalization, or expropriation (each of
which, a "Taking") by any authority or entity possessing such power, then each
Party shall be excused from performance of its obligations to the extent
provided in Section 17.1. Provider shall give Customer notice of any proposed
Taking within fifteen (15) days of Provider itself receiving notice of any
proceedings. In the proceeding for any such Taking or an involuntary
discontinuance of the use of a portion of the Collocation Site or the Customer
Fibers in anticipation of a Taking, the interests of Customer and Provider in
the affected portion shall be severed. Any awards resulting from the proceeding
or otherwise provided shall be allocated between Customer and Provider in
accordance with such interests. In addition, Customer and Provider shall each be
entitled to claim and receive the portion of the total award attributable to its
interest in the affected assets and may claim damages payable on account of
relocation or re-routing expenses relating to the Taking.

                      ARTICLE XVIII. SETTLEMENT OF DISPUTES

18.1 OBLIGATION TO ARBITRATE. Any dispute or disagreement relating to this
Agreement or any matter arising between Customer and Provider in connection with
this Agreement which is not settled to the mutual satisfaction of Customer and
Provider within 30 calendar days from the date that either party informs the
other in writing that such dispute or disagreement exists, shall be settled by
arbitration by a single arbitrator in Chicago, Illinois, in accordance with the
Commercial Arbitration Rules of the American Arbitration Association in effect
on the date that such notice is given. If the parties are unable to agree on a
single arbitrator within fifteen calendar days, the American Arbitration
Association shall select an arbitrator. The decision of the arbitrator shall be
final and binding upon the parties and shall include written findings of law and
fact, and judgment may be obtained thereon by either party in a court of
competent jurisdiction. Each party shall bear the cost of preparing and
presenting its own case. The cost of the arbitration, including the fees and
expenses of the arbitrator, shall be shared equally by the parties unless the
award otherwise provides.

18.2 EXCEPTIONS TO ARBITRATION OBLIGATION. The obligation herein to arbitrate
shall not be binding upon any party with respect to requests for preliminary
injunctions, temporary restraining orders or other procedures in a court of
competent jurisdiction to obtain interim relief when deemed necessary by such
court to preserve the status quo or prevent irreparable injury pending
resolution by arbitration of the actual dispute.

                                       19
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

                       ARTICLE XIX. RULES OF CONSTRUCTION

19.1 INTERPRETATION. The captions or headings in this Agreement are strictly for
convenience and shall not be considered in interpreting this Agreement or as
amplifying or limiting any of its content. Words in this Agreement that import
the singular connotation shall be interpreted as plural, and words that import
the plural connotation shall be interpreted as singular, as the identity of the
Parties or objects referred to may require. References to "person" or "entity"
each include natural persons and legal entities, including corporations, limited
liability companies, partnerships, sole proprietorships, business divisions,
unincorporated associations, governmental entities, and any entities entitled to
bring an action in, or that are subject to suit in an action before, any state
or federal court of the United States. The word "including" means "including,
but not limited to." "Days" refers to calendar days, except that references to
"banking days" exclude Saturdays, Sundays and holidays during which nationally
chartered banks in the United States are authorized or required to close. Unless
expressly defined herein, words having well-known technical or trade meanings
shall be so construed.

19.2 CUMULATIVE REMEDIES; INSURANCE. Except as set forth to the contrary herein,
any right or remedy of Provider or Customer shall be cumulative and without
prejudice to any other right or remedy, whether contained herein or not. The
provisions of Article XII (Insurance) shall not be construed as limiting the
Indemnitor's obligations pursuant to Article X (Indemnification) or other
provisions of this Agreement.

19.3 NO THIRD-PARTY RIGHTS. Nothing in this Agreement is intended to provide any
legal rights to anyone not an executing Party of this Agreement except under the
indemnification and insurance provisions and except that Underlying Landlord and
Facility Owners/Lenders shall be entitled to rely on and have the benefit of
Sections 8.3, 10.1, 11.2 and 11.3.

19.4 AGREEMENT FULLY NEGOTIATED. This Agreement has been fully negotiated
between and jointly drafted by Provider and Customer.

19.5 INDUSTRY STANDARDS. Except as otherwise set forth herein, for the purpose
of this Agreement the normal standards of performance within the
telecommunications industry in the relevant market shall be the measure of
whether a Party's performance is reasonable and timely.

19.7 CROSS REFERENCES. Except as the context otherwise indicates, all references
to Exhibits, Articles, Sections, Subsections, Clauses, and Paragraphs refer to
provisions of this Agreement.

19.8 LIMITED EFFECT OF WAIVER. The failure of either Provider or Customer to
enforce any of the provisions of this Agreement, or the waiver thereof in any
instance, shall not be construed as a general waiver or relinquishment on its
part of any such provision, but the same shall nevertheless be and remain in
full force and effect.

19.9 APPLICABLE LAW. The domestic laws of the State of New York, without
reference to its choice of law principles, shall govern this Agreement and it
shall be construed accordingly. The laws of such state shall govern all disputes
referred to arbitration and the statute of limitations and the remedies for any
wrongs that may be found.

                                       20
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

19.10 SEVERABILITY. If any term, covenant or condition in this Agreement shall,
to any extent, be invalid or unenforceable in any respect under the laws
governing this Agreement, the remainder of this Agreement shall not be affected
thereby, and each term, covenant or condition of this Agreement shall be valid
and enforceable to the fullest extent permitted by law.

19.11 NO PARTNERSHIP CREATED. The relationship between Provider and Customer
shall not be that of partners, agents, or joint venturers for one another, and
nothing contained in this Agreement shall be deemed to constitute a partnership
or agency agreement between them for any purposes, including federal income tax
purposes. Provider and Customer, in performing any of their obligations
hereunder, shall be independent contractors or independent parties and shall
discharge their contractual obligations at their own risk.

                             ARTICLE XX. ASSIGNMENT

20.1 RESTRICTIONS ON ASSIGNMENT. Except as provided in the second sentence of
this Section and Section 20.4, neither party shall assign or otherwise transfer
this Agreement or its rights or obligations hereunder to any other party without
the prior written consent of the other party, which consent shall not be
unreasonably withheld or delayed. Either party shall have the right, without the
other party's consent, to assign or otherwise transfer this Agreement in whole
or in part as collateral to any lender or to any of its Affiliate's or to any
corporation into which it may be merged or consolidated or which purchases all
or substantially all of its assets.

20.2 AGREEMENT BINDS SUCCESSORS. This Agreement and each of the parties'
respective rights and obligations under this Agreement, shall be binding upon
and shall inure to the benefit of the parties hereto and each of their
respective successors and permitted assigns. Any assignment or transfer shall be
subject to the other party's rights under this Agreement and any assignee or
transferee shall continue to perform the assigning party's obligations under
this Agreement.

20.3 CONDITIONS TO EFFECTIVE ASSIGNMENT. Except as otherwise stated herein, an
assignment (or other transfer) of this Agreement or a Party's rights or
obligations hereunder to any other party shall not be effective without (a)
either the prior written consent of the non-assigning party, or, if such consent
is not required, written notice to the non-assigning Party and (b) the written
agreement of the assignee to be bound by the indemnification provisions and
limitations on liability and recourse set forth in this Agreement.

20.4 TRANSFER OF COLLOCATION RIGHTS. In addition to the collocation rights of
Customer set forth in this Agreement, Customer shall, at any time during the
Term of this Agreement, have the right to obtain rack space and associated
collocation services from Provider at Provider's standard rates, terms and
conditions, subject to availability in Provider's good faith reasonable
discretion (the "Full Price Collocation Rights"). Further, Customer may convey
its interest, in whole or in part, in such "Full Price Collocation Rights. .Any
such conveyance by Customer shall not release Customer of its duties,
obligations and liabilities hereunder and any and all of the rights and
interests of the transferee of such collocation space and services shall be
subject to the terms and provisions of this Agreement.

                                       21
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

20.5 CHANGE IN CONTROL NOT AN ASSIGNMENT. Notwithstanding any presumptions under
applicable state law that a change in control of a Party constitutes an
assignment of an agreement, a change in control of a Party, not made for
purposes of circumventing restrictions on assignment or of depriving the other
Party of rights under this Agreement, shall not be deemed an assignment for
purposes of this Agreement.

20.6 RIGHT TO SUBCONTRACT. Provider may subcontract for testing, maintenance,
repair, restoration, relocation, or other operational and technical services it
is obligated to provide hereunder or may have the underlying facility owner or
its contractor perform such obligations.

               ARTICLE XXI. ENTIRE AGREEMENT; AMENDMENT; EXECUTION

21.1 INTEGRATION; EXHIBITS. This Agreement constitutes the entire and final
agreement and understanding between Provider and Customer with respect to the
subject matter hereof and supersedes all prior agreements relating to the
subject matter hereof, which are of no further force or effect. The Exhibits
referred to herein are integral parts hereof and are made a part of this
Agreement by reference.

21.2 NO PAROLE AMENDMENT. This Agreement may only be amended, modified, or
supplemented by an instrument in writing executed by duly authorized
representatives of Provider and Customer.

21.3 COUNTERPARTS. This Agreement may be executed in one or more counterparts,
all of which taken together shall constitute one and the same instrument.

21.4 FACSIMILE DELIVERY. This Agreement may be duly executed and delivered by a
Party by execution and facsimile delivery of the signature page of a counterpart
to the other Party, provided that, if delivery is made by facsimile, the
executing Party shall promptly deliver a complete counterpart that it has
executed to the other Party.

IN WITNESS WHEREOF and in confirmation of their consent to the terms and
conditions contained in this Agreement and intending to be legally bound hereby,
Provider and Customer have executed this Agreement as of the Effective Date.

<Table>
<Caption>
WILLIAMS COMMUNICATIONS, LLC                     METROMEDIA FIBER NETWORK
                                                 SERVICES, INC.
<S>                                              <C>
By:       /s/ Howard E. Janzen                   By:         /s/ William G. La Perch
   ----------------------------------------         ----------------------------------------

Print Name:       Howard E. Janzen               Print Name:       William G. La Perch
           --------------------------------                 --------------------------------

Title:            President & CEO                Title:            President
      -------------------------------------            -------------------------------------
</Table>

                                       22
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EXECUTION COPY                                                     CONFIDENTIAL

                                    EXHIBIT A
                                COLLOCATION SITES
<Table>
<Caption>
                          RACK LOCATION
                          -------------                                           NUMBER
 MARKET                             LOCATION                                     OF RACKS
 ------                             --------                                     --------
<S>                  <C>                                                         <C>
Atlanta              56 Marietta                                                    9
                     56 Marietta (PAIX)                                             2

Connecticut          3 Shaws Cove, New London                                       3

Dallas               1950 Stemmons Freeway                                          9
                     1950 Stemmons Freeway (PAIX)                                   2
                     5800 Granite Plaza                                             2

Delaware             222 Delaware Avenue, Wilmington                                5

Houston              1301 Fannin                                                    9

Illinois             810 Jorie Boulevard, Oak Brook                                 5
                     700 South Federal                                              9
                     5201 Rosemont                                                  2

Long Island          1101 Stewart Avenue, Garden City                               5

Massachusetts        1 Summer Street, Boston                                        9
                     701 Waverly Place, Framingham                                  5

New Jersey           744 Broad Street, Newark                                       5
                     Main Street, Woodbridge                                        2

New York             111 Eighth Avenue, New York                                    9
                     95 Church Street, White Plains                                 1
                     111 Eighth Avenue, New York (PAIX)                             2

Philadelphia         401 North Broad Street                                         5

Rhode Island         King's Factory Road, Green Hill                                5
                     1205 Westminster Street, Providence                            5

San Francisco        501 Second Avenue                                              3
                     529 Bryan, Palo Alto (PAIX)                                    8

Seattle              2001 Sixth Avenue                                              9
                     2001 Sixth Avenue (PAIX)                                       2

Washington, D.C.     8300 Greensboro, McLean, VA                                    2
                     7990 Science Applications Cout, Vienna, VA (PAIX)              5
                     2100 "M" Street                                                9
                                                                                  -----
                                                                                   148
</Table>

                               Exhibit A - Page 1

<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

                                Exhibit B, Page 4

                                    EXHIBIT B

                            OPERATIONS SPECIFICATIONS

1. MAINTENANCE

A. NCC Functions. Provider shall operate a manned Network Control Center ("NCC")
twenty-four (24) hours a day, seven (7) days a week that monitors the Customer
Fiber by means of remote surveillance equipment and dispatches maintenance and
repair personnel to handle and repair problems detected by the NCC or reported
by Customer or other parties. Provider shall provide Customer a toll-free
telephone number to report problems to the NCC.

B. Fiber Maintenance. Provider shall perform appropriate routine maintenance on
the Customer Fiber in accordance with Provider's then-current preventative
maintenance procedures. Provider's preventative maintenance procedures shall not
substantially deviate from industry practice.

C. Collocation Site Maintenance. Provider shall perform appropriate routine
maintenance on regenerator, optical amplifier, and junction buildings, including
the DC power plant, HVAC equipment, and basic building safety equipment
including alarms and emergency generators in accordance with Provider's then
current preventative maintenance procedures. Provider's maintenance procedures
shall not substantially deviate from industry practice.

D. Route Patrol. Provider shall patrol the route on a reasonable, routine basis
and shall perform all required cable locates. Provider shall belong to a state
or regional one-call (call-before you dig) center when available.

E. Spare Cable. Provider shall maintain an inventory of spare cable at strategic
locations to facilitate timely restoration.

2. PLANNED NETWORK MAINTENANCE PROCEDURE (PNMP)

A. Timing. Provider shall avoid performing maintenance between 0600-2200 Central
time, Monday through Friday, inclusive, that will have a disruptive impact on
the continuity or performance level of the Customer Fibers. However, the
preceding sentence does not apply to restoration of continuity to a severed or
partially severed fiber optic cable, restoration of dysfunctional power and
ancillary support equipment, or correction of any potential jeopardy conditions.

B. Notice. Provider shall provide Customer with telephone, facsimile, or written
notice of all non-emergency planned network maintenance (a) no later than three
business days prior to performing maintenance that, in its reasonable opinion,
has a substantial likelihood of affecting Customer's traffic for up to 50
milliseconds, and (b) no later than ten business days prior to performing
maintenance that, in its reasonable opinion, has a substantial likelihood of
affecting Customer's traffic for more than 50 milliseconds. If Provider's
planned activity is canceled or

                               Exhibit B, Page 1
<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

delayed, Provider shall promptly notify Customer and shall comply with the
provisions of the previous sentence to reschedule any delayed activity.

C. PNMP Updates. Provider may update it's PNMP and Technical Assistance
Procedure from time to time so long as the changes in procedures are reasonable
and no less favorable to the Customer. Provider shall promptly provide Customer
a copy of its then current PNMP and Technical Assistance Procedure documents
upon Customer's request. Customer hereby acknowledges receipt of Provider's PNMP
and Technical Assistance Procedure documents dated February 11, 2002.

3. FIBER AND CABLE

A. Emergency Repair. Provider shall correct or repair cable discontinuity or
damage. Provider shall use commercially reasonable efforts to repair cable
traffic discontinuity within the following timeframes:

         o        Dispatch of personnel to problem area - immediately upon
                  learning of discontinuity

         o        Arrival of first maintenance employee on site - within four
                  (4) hours of learning of discontinuity

         o        Restoration of cable continuity - continuity of at least one
                  fiber shall be established within six (6) hours of learning of
                  discontinuity; restoration shall continue until all in-service
                  fibers are restored

         o        Electronic failure response time is two (2) hours.

B. Permanent Repair. Within twenty-four (24) hours after completion of an
emergency repair, Provider shall commence its planning for permanent repair,
shall notify Customer of such plans, and shall implement such permanent repair
within an appropriate time thereafter.

C. Splicing Specifications. Provider shall comply with the cable splicing
specifications as provided in the Fiber Lease Agreement. Provider shall provide
to Customer any modifications to these specifications for Customer's approval,
which shall not be unreasonably withheld or delayed, so long as the
modifications do not substantially deviate from industry standards.

4. MISCELLANEOUS

A. Full-Time Dispatch Capability. Provider's maintenance employees shall be
available for dispatch twenty-four (24) hours a day, seven (7) days a week.
Provider shall use commercially reasonable efforts to have its first maintenance
employee at the site requiring an emergency maintenance activity within four (4)
hours from the time of alarm identification by Provider's NCC or notification by
Customer, whichever occurs first. Emergency maintenance is defined as any
service-affecting situations requiring an immediate response.

B. Standard of Care; Cooperation. In performing its services hereunder, Provider
shall take workmanlike care to prevent impairment to the signal continuity and
performance of the System. In addition, Provider shall reasonably cooperate with
Customer in sharing information and analyzing the disturbances regarding the
cable and/or fiber facilities.

                                Exhibit B, Page 2

<PAGE>

EXECUTION COPY                                                     CONFIDENTIAL

C. Customer Equipment. Nothing contained herein shall make Provider responsible
for Customer Equipment. If, however, Provider agrees to maintain Customer
Equipment, Customer shall provide equipment spares, vendor training and
documentation for each technician along the System route when Customer uses
equipment different from that used by Provider.

D. Escalation List. Provider shall, at Customer's request, provide Customer an
operations escalation list for use in reporting and seeking redress of
exceptions noted in Provider's performance of maintenance.

                               Exhibit B, Page 3

<PAGE>

EXECUTION COPY

CONFIDENTIAL PORTION MARKED [*************] HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT AND FILED SEPARATELY WITH THE SECURITIES
AND EXCHANGE COMMISSION.

            FIRST AMENDMENT TO COLLOCATION AND MAINTENANCE AGREEMENT

         THIS FIRST AMENDMENT (this "Amendment") is made by and between
METROMEDIA FIBER NETWORK SERVICES, INC., a Delaware corporation ("Provider") and
WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability company ("Customer").

                                   Background

Provider and Customer are parties to the Collocation and Maintenance Agreement
dated April 26, 2002 (the "Agreement").

On May 20, 2002, Provider and most of its direct and indirect domestic
subsidiaries each filed voluntary petitions for reorganization pursuant to
Chapter 11 of title 11 of the United States Code. (the "Bankruptcy Code") with
the United States Bankruptcy Court for the Southern District of New York (the
"Bankruptcy Court") and Provider is currently operating its business and
managing its property as a debtor-in-possession (the "Pending Bankruptcy Case").

The parties now wish to amend the Agreement in accordance with the terms set
forth in this Amendment.

NOW THEREFORE, for mutual consideration, the value of which the parties
acknowledge, the terms of the Agreement are amended as follows:

1. Capitalized terms not otherwise defined in this Amendment have the meaning
ascribed in the Agreement.

2. EXHIBIT A is replaced with EXHIBIT A-1, attached to this Amendment.

3. Section 2.1 is deleted and replaced with the following:

"CHARGES FOR MAINTENANCE. Customer shall pay Provider a maintenance fee of
[*****] per fiber mile, per month for the maintenance services set forth in
Article 6 of this Agreement, such amount totaling [*******] per month (30,740
fiber miles x [**]). Invoices for such maintenance services shall be issued
monthly."

4. Section 2.6 (a) is modified by removing the reference to "PAIX locations' and
2.6(c) is deleted in its entirety.

5. Section 3.1(c) is modified by adding the following sentence at the end:

"Notwithstanding the foregoing, Customer is not entitled to reimbursement or the
cash equivalent of the Rack Credits under any circumstances, including
termination of this Agreement prior to expiration of the Rack Credits."

CONFIDENTIAL
PAGE 1 OF 3
<PAGE>

EXECUTION COPY

6. Section 3.2 is deleted and replaced with the following:

         "As of the effective date of the First Amendment to this Agreement,
Provider agrees to provide and Customer agrees to pay for the Collocation Sites
and corresponding number of racks identified in EXHIBIT A-1 together with
associated collocation services ordered by Customer. From time to time, Customer
may order additional Basic Services and Additional Services at Provider's
Collocations Sites in accordance with Section 3.5(a).

7. EFFECTIVE DATE. This Amendment is effective upon the date of the last
signature hereto ("Effective Date"). The parties agree that the new monthly
billing rate as specified in paragraph 6 of this Amendment is effective October
1, 2002. To be sure, any invoices rendered during September 2002 for October
services, will be adjusted accordingly. Notwithstanding the foregoing, the
parties acknowledge that the Amendment must be approved by the Bankruptcy Court
pursuant to an order, in form and substance acceptable to Provider and Customer,
which provides for, among other things, the following: (i) assumption of the
Agreement, as amended, pursuant to section 365 of the Bankruptcy Code, and (ii)
a finding that the parties negotiated the Amendment at arm's length and in good
faith. If such approval is not obtained on or before October 17, 2002 or such
later date as the parties may agree to, this Amendment will be null and void and
of no force or effect and Customer agrees to pay the difference between the
amended amounts invoiced for October and the actual amounts owed under the
Agreement.

8. ASSUMPTION AND WAIVER OF SPECIFIC CLAIMS. If following the assumption of the
Agreement:

         (a) one or more metro fiber rings currently operated by Provider on
which Customer has collocation racks or fiber, is effectively abandoned because
Provider elects no longer to operate those markets and the markets are sold to a
third party, then any damage claim of Customer arising from the effective
abandonment of any such market is a general unsecured claim in the Pending
Bankruptcy Case; and/or

         (b) one or more, but less than all, Provider's metropolitan networks
are sold to a third party who intends to operate such networks, then, subject to
Customer's rights under section 365 of the Bankruptcy Code as described below,
Customer and Provider will execute a new agreement in all respects identical to
the existing Agreement but which includes only the markets sold to a third
party. The new agreement may be assigned by Provider to the third party pursuant
to section 365 of the Bankruptcy Code, and the existing Agreement will be deemed
amended to eliminate the assigned fiber and collocation racks from its scope.
The occurrence of events contemplated by this subparagraph is not a breach by
Provider of the Agreement and will not give rise to a claim. Customer may object
to any assignment pursuant to section 365 of the Bankruptcy Code on the grounds
that Customer is not receiving adequate assurance of future performance or that
an assignment to the third party assignee in question is otherwise not permitted
under the Bankruptcy Code; provided, however, that in the event Customer's
objection to such assignment is sustained but the relevant network is
nevertheless sold to the third party, the parties agree that damages, if any,
arising from the breach resulting from Provider's inability to provide service
to Customer under the Agreement with respect to the markets sold to the third
party, will be a general unsecured claim in the Pending Bankruptcy Case; or

CONFIDENTIAL
PAGE 2 OF 3

<PAGE>

EXECUTION COPY

(c) the Agreement is terminated due to Provider's failure to perform or its
rejection thereof, nothing herein constitutes a waiver of Customer's right to a
general unsecured claim for all outstanding Pre-Petition Debt and an
administrative claim for post-petition damages caused by any breach of the
Agreement, or of the right of Provider or any party in interest to object to any
such claim. Any and all administrative expense claims will require Williams
Communications to satisfy the requirements of the Bankruptcy Code to establish
the claim and is without prejudice to any other party's right to contest such
claim.

9. Except as amended, all of the original terms and conditions of the Agreement
continue in full force and effect, neither party is in currently in default, and
the Agreement, as amended, is hereby ratified and confirmed.

The parties have executed this Amendment on the dates set forth below.

METROMEDIA FIBER NETWORK SERVICES, INC., a Delaware corporation

Signature:        /s/ William G. La Perch
          -----------------------------------------------

(Print) Name:     William G. La Perch
              -------------------------------------------

(Print) Title:    Sr. Vice President
              -------------------------------------------

(Print) Date:     10/10/02
             --------------------------------------------

WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability company

Signature:        /s/ Frank M. Semple
          -----------------------------------------------

(Print) Name:     Frank M. Semple
              -------------------------------------------

(Print) Title:    Chief Operating Officer
              -------------------------------------------

(Print) Date:     10/2/02
             --------------------------------------------

CONFIDENTIAL
PAGE 3 OF 3

<PAGE>

EXECUTION COPY

                                    EXHIBIT A

<Table>
<Caption>
                     RACK LOCATION
------------------------------------------------------------          NUMBER
     MARKET                       LOCATION                           OF RACKS
-----------------    ---------------------------------------         --------
<S>                     <C>                                         <C>

Atlanta                 56 Marietta                                      9

Connecticut             3 Shaws Cove, New London                         3

Dallas                  1950 Stemmons Freeway                            9
                        5800 Granite Plaza                               2

Delaware                222 Delaware Avenue, Wilmington                  5

Houston                 1301 Fannin                                      9

Illinois                810 Jorie Boulevard, Oak Brook                   5
                        700 South Federal                                9
                        5201 Rosemont                                    2

Long Island             1101 Stewart Avenue, Garden City                 5

Massachusetts           1 Summer Street, Boston                          9
                        701 Waverly Place, Framingham                    5

New Jersey              744 Broad Street, Newark                         5
                        Main Street, Woodbridge                          2

New York                111 Eighth Avenue, New York                      9
                        95 Church Street, White Plains                   1

Philadelphia            401 North Broad Street                           5

Rhode Island            King's Factory Road, Green Hill                  5
                        1205 Westminster Street, Providence              5

San Francisco           501 Second Avenue                                3

Seattle                 2001 Sixth Avenue                                9

Washington, D.C.        8300 Greensboro, McLean, VA                      2
                        2100 "M" Street                                  9
                                                                      ----
                                                                       127
                                                                      ====
</Table>

CONFIDENTIAL
EXHIBIT A-1

<PAGE>

EXECUTION COPY                                                      CONFIDENTIAL

CONFIDENTIAL PORTION MARKED [*************] HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT AND FILED SEPARATELY WITH THE SECURITIES
AND EXCHANGE COMMISSION.

                               LEASE AGREEMENT #2

                              DATED APRIL 26, 2002

                                     BETWEEN

                     METROMEDIA FIBER NETWORK SERVICES, INC.

                                       AND

                          WILLIAMS COMMUNICATIONS, LLC

<PAGE>
EXECUTION COPY                                                      CONFIDENTIAL

                                TABLE OF CONTENTS

<Table>
<S>         <C>                                                            <C>
ARTICLE 1.  DEFINITIONS......................................................1
ARTICLE 2.  NEW CITIES OR ROUTES.............................................4
ARTICLE 3.  GRANT OF LEASE AND BUILDING ACCESS...............................4
ARTICLE 4.  CONSIDERATION; FEES..............................................5
ARTICLE 5.  DELIVERY AND ACCEPTANCE..........................................7
ARTICLE 6.  COLLOCATION AND MAINTENANCE.....................................10
ARTICLE 7.  AUTHORIZATIONS..................................................10
ARTICLE 8.  Intentionally Omitted...........................................11
ARTICLE 9.  INTERCONNECTION OF LESSEE'S SYSTEM..............................11
ARTICLE 10. USE OF THE LESSEE FIBER.........................................13
ARTICLE 11. PAYMENT TERMS...................................................14
ARTICLE 12. INDEMNIFICATION.................................................14
ARTICLE 13. INSURANCE.......................................................15
ARTICLE 14. Taxes and Franchise, License and Permit Fees....................16
ARTICLE 15. Notice..........................................................17
ARTICLE 16. Confidentiality and Publicity...................................18
ARTICLE 17. DEFAULT.........................................................18
ARTICLE 18. FORCE MAJEURE...................................................20
ARTICLE 19. ARBITRATION.....................................................20
ARTICLE 20. ASSIGNMENT......................................................21
ARTICLE 21. RULES OF CONSTRUCTION...........................................21
ARTICLE 22. Representations and Warranties..................................23
ARTICLE 23. LIMITATIONS OF LIABILITY........................................24
ARTICLE 24. Audit Rights....................................................25
ARTICLE 25. IMPROPER PAYMENTS PROHIBITED....................................25
ARTICLE 26. ENTIRE AGREEMENT; AMENDMENT; EXECUTION..........................26
</Table>

EXHIBITS
EXHIBIT A         FIBER TESTING SPECIFICATIONS
EXHIBIT B         MFN DATA CENTERS
EXHIBIT C         FORM OF AS-BUILTS
EXHIBIT D         CONSTRUCTION SPECIFICATIONS

                                       i
<PAGE>
EXECUTION COPY                                                      CONFIDENTIAL

                               LEASE AGREEMENT # 2

         THIS LEASE AGREEMENT # 2 (this "Agreement #2") is made as of the 26 day
of April, 2002, (the "Effective Date") by and between METROMEDIA FIBER NETWORK
SERVICES, INC., a Delaware corporation ("MFN") and WILLIAMS COMMUNICATIONS, LLC,
a Delaware limited liability company ("Lessee").

BACKGROUND

         A. MFN owns or controls metropolitan and intercity fiber optic
communication systems in the continental United States and Europe (collectively,
the "MFN System");

         B. Contemporaneously herewith, the parties will execute a separate
Fiber Lease Agreement for 43,040 identified fiber miles of dark fiber within the
MFN System. From time to time after the Effective Date, Lessee may desire to
lease additional fiber miles within the MFN System from MFN, and MFN desires to
lease such additional fiber miles to Lessee and the parties intend the terms and
conditions of this Agreement #2 to govern such additional orders from Lessee.

                              TERMS OF AGREEMENT #2

Accordingly, in consideration of the mutual promises set forth below, the
contemporaneous execution of those certain two Fiber Lease Agreements by the
parties, the termination of those certain two (2) Fiber Lease Agreements dated
September 16, 1999 and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereby agree as
follows:

                             ARTICLE 1. DEFINITIONS

The following terms shall have the stated definitions in this Agreement #2.

"ACCEPTANCE DATE" means the date when Lessee delivers (or is deemed to have
delivered) a notice of acceptance with respect to each delivery of Lessee Fiber
and/or Buildings as further described in Section 5.3.

"AFFILIATE" means, with respect to any entity, an entity controlling, controlled
by, or under common control with such entity by means of direct or indirect
equity ownership or otherwise. As used in this Agreement #2, "control" shall
mean possession, directly or indirectly, of the power to direct or cause the
direction of the management and policies of a person or entity, whether through
the ownership of voting securities, by contract or otherwise.

"BUILDING" means any commercial building, central office, MFN Data Center or
point-of-presence ("POP").

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"BUILDING ACCESS" is defined as Lessee's use of a MFN-owned fiber optic lateral
connection and termination facilities for the purpose of interconnecting the
Lessee Fiber at a Building.

"BUILDING ACCESS PAYMENT" is the monthly recurring fee payable by Lessee for
Building Access as set forth in Section 4.2.

"CONFIDENTIAL INFORMATION" shall have the meaning set forth in Section 16.1.

"COSTS" means actual and directly related costs accumulated in accordance with
the established accounting procedure used by MFN or Lessee or their respective
contractors or subcontractors, as the case may be, which costs include the
following: (a) labor costs, including wages, salaries, benefits and overhead
allocable to such labor costs (Lessee's or MFN's overhead allocation percentage
shall not exceed the lesser of (i) the percentage such party allocates to its
internal projects or (ii) one hundred and thirty percent (130%), and (b) other
direct costs and out-of-pocket expenses on a pass-through basis (e.g.,
equipment, materials, supplies, contract services, etc.).

"DATA CENTER ACCESS" refers to the interconnection of Lessee Fiber with an MFN
Data Center.

"DELIVERY DATE" means each date MFN delivers or previously delivered Lessee
Fiber and/or Buildings to Lessee, including, with respect to the Lessee Fiber,
all test deliverables.

"DEMARCATION POINT" means the point where MFN's installation, maintenance and
operation obligations terminate.

"DIVERSITY" means the provision of physically separated optical facilities that,
when equipped with suitable optronics, are capable of providing an alternate
transmission path without human or mechanical intervention. The alternate
facilities shall, except at each Demarcation Point, have at least thirty (30)
feet of separation in any direction and shall not be on the same poles, towers,
river crossings, bridges, viaducts, elevated walkways, or similar structures.

"EQUIPMENT" means Lessee's electronic, optronic and power equipment necessary
for the operation of the Cable.

"FACILITY OWNERS/LENDERS" means any entity (other than MFN): (a) owning any
portion of the System or any property or security interest therein, (b) leasing
to MFN, or providing an Lease to MFN in, any portion of the System, or (c) that
is a lender (including any party holding legal title or a security interest in
the MFN System as a MFN or a creditor) with respect to MFN or any Affiliates of
MFN.

"FIBER ACCEPTANCE TESTING" shall have the meaning set forth in Section 5.3(a).

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"FIBER TESTING SPECIFICATIONS" are set forth in Exhibit A.

"LESSEE FIBER" shall have the meaning set forth in Section 3.1.

"MFN DATA CENTER" refers to the Internet data centers (f/n/a AboveNet data
centers and not including any locations owned by PAIX.net) owned or controlled
by MFN and listed in Exhibit B.

"NEW CITY NOTICE" shall have the meaning ascribed to it in Article 2 of this
Agreement #2.

"PRODUCT ORDER" is defined in Section 3.1.

"RELEASED PARTY" means each of the following:

         (a) any Affiliates of the other party and any Facility Owners/Lenders;

         (b) any employee, officer, director, stockholder, partner, member, or
trustee of the other party or of its Affiliates or Facility Owners/Lenders; or

         (c) assignees of the entities included in the above subparagraphs (a)
or (b) and any employee, officer, director, stockholder, partner, member, or
trustee of such assignees.

"RIGHT-OF-WAY AUTHORIZATIONS" means any underlying agreements, easements,
permits, or licenses, by which MFN obtains rights to perform its obligations
hereunder with respect to the MFN System, Buildings and Lessee's Fibers from:

         (a) underlying owners of real or personal property, or right-of-way
holders,

         (b) grantors of Lease or other rights or licenses with respect to all
or a portion of its System,

         (c) parties granting duct usage and pole attachment rights, and

         (d) any governmental authority (including franchising agencies,
environmental regulation agencies, and public utility commissions).

"SPLICE POINT" is defined in Section 9.2.

"TERM" of this Agreement #2 begins on the Effective Date and expires 20 years
after the latest Acceptance Date (the "Expiration Date") under this Agreement.

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                         ARTICLE 2. NEW CITIES OR ROUTES

MFN will provide Lessee information and maps regarding newly constructed or
newly available portions of the MFN System within 30 days after the new portions
are made available to any MFN customers.

                  ARTICLE 3. GRANT OF LEASE AND BUILDING ACCESS

3.1 GENERAL. From time to time during the Term, Lessee may request to lease
fiber miles and building access from MFN. MFN will respond to all such requests
within 15 days. If the requested fiber miles and/or building access is available
as determined in MFN's good faith reasonable discretion, the parties will
execute "Product Orders". Each fully executed Product Order is automatically
incorporated by reference into the Agreement #2. Each Product Order will set
forth the number of fiber strands (the "Lessee Fiber"), identify Buildings,
state all recurring and non-recurring fees, estimate a Delivery Date and set
forth any other relevant terms agreed upon by the parties.

3.2 FIBER. Lessee is entitled to order a maximum of 42,024 FIBER MILES under
this Agreement #2. Unless otherwise converted to an IRU pursuant to Section 3.5,
MFN grants to Lessee a lease in the Lessee fiber for a period of 20 years
beginning on the Acceptance Date.

At any time during the Term, Lessee may substitute between 6 and 96 Lessee Fiber
for Lessee Fiber in any other segment(s) provided: (i) Lessee Fiber in such
other segment(s) are available as determined in MFN's good faith reasonable
discretion; (ii) such Lessee Fiber have not yet been spliced in order to
establish interconnections by Lessee; (iii) such substitution does not leave
less than 6 fibers in such segment; (iv) Lessee shall be responsible for the
Costs related to the splicing and re-testing arising from Lessee's specific
request for substitution of Lessee Fiber, if applicable (not to include Costs
for splicing or testing for the normal delivery of Lessee Fiber); and (v) though
the number of such substitutions are not limited, Lessee will use reasonable
business judgment to make substitutions based upon a good faith determination of
the need therefore.

3.3 LEASE LIMITATIONS. The Lease granted to Lessee hereunder and any rights
granted by Lessee to third party users, are subject to all Right-of-Way
Authorizations applicable to the MFN System and the Buildings. Lessee will
adhere to the requirements of all such Right-of-Way Authorizations. The Lease of
the Lessee Fiber hereunder does not convey any legal title to any real or
personal property, including the fibers, cable, or the MFN System. This Lease
does not include any Equipment used to transmit capacity over, or to "light,"
the Lessee Fiber.

3.4 BUILDING ACCESS.

         (a) From time to time during the Term, Lessee may request that MFN
connect Lessee Fibers to Buildings under the terms and conditions of this
Agreement. Within 15 days of Lessee's request, if accepted, MFN will provide
Lessee with its then-current order form specifying the

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Building Access Payment, any non-recurring charges (as set forth in Section 4.3)
and the anticipated Delivery Date of the requested Building (each such order
form a "Product Order"). Lessee must sign the Product Order and return to MFN
within 15 days. All Product Orders signed by both parties are governed by and
incorporated by reference into this Agreement.

         (b) MFN shall design, engineer, install, and construct or acquire fiber
and terminate such fiber necessary to provide Building Access. All such
terminations established by MFN within the MFN System shall comply with the
relevant Fiber Testing Specifications (including the splice loss and optical
fiber specifications) set forth in Exhibit A and with relevant
telecommunications industry practices. MFN shall use commercially reasonable
efforts to provide all Building terminations with Diversity.

         (c) If MFN rejects the Building request or Lessee rejects the Product
Order, Lessee has the option of either:

                  (i) requesting that MFN participate with Lessee in a joint
         construction effort to make such interconnection pursuant to a separate
         agreement negotiated between the parties that shall not require a
         Building Access Payment; or

                  (ii) requesting that MFN construct the lateral connection as
         Lessee's contractor pursuant to a separate agreement negotiated between
         the parties. If MFN accepts, Lessee will own the lateral connection and
         related facilities and Lessee will pay the one time charge for the
         connection at Cost; or

                  (iii) constructing and owning the lateral connection to the
         Building and interconnecting to the MFN backbone at a Splice Point in
         accordance with Section 9.2, below. Lessee, in its good faith
         discretion, may permit MFN to utilize Williams' interconnection
         facilities to connect to a Building. There is no Building Access
         Payment associated with Splice Point interconnection.

3.5 CONVERSION TO IRU. At any time during the Term, upon the request of Lessee
and Lessee's payment to MFN of the net present value of the Lease Payments and
Building Access Payments calculated based upon a mutually agreed upon discount
rate, MFN shall grant to Lessee an Indefeasible Right of Use to the Lessee Fiber
and Building terminations equal to the remaining term of this Agreement #2.

                         ARTICLE 4. CONSIDERATION; FEES

4.1 LEASE PAYMENTS. Lessee shall make monthly payments to MFN in advance during
the Term, in an amount calculated as [*****} PER FIBER MILE PER MONTH based on
the fiber miles set forth in each Product Order ("Lease Payments"). MFN
represents that the fiber miles stated in each Product Order, are either the
actual fiber miles (calculated as the route miles traversed by the Lessee Fiber

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multiplied by the number of Lessee Fiber on the route) or a bona fide estimate
thereof, such estimate calculated utilizing OTDR distances less ten percent
(10%).

4.2. BUILDING ACCESS PAYMENT. Except as provided in Section 3.4, in exchange for
Building Access at each Building, Lessee shall make monthly payments to MFN in
advance ("Building Access Payment").

         (a) The Building Access Payment is calculated as follows:

<Table>
<Caption>
               Total                            Price per
          Number of fibers                       fiber per
             terminated                       interconnection
          ----------------                    ---------------
<S>                                          <C>

                  [*]                            [*******]
                  [*]                             [******]
                  [*]                             [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
                  [**]                            [******]
</Table>

         (b) The Building Access Payment for each termination in a Building is
reduced by [***] for the period beginning on the Acceptance Date of the Building
and ending on the first anniversary of such acceptance.

         (c) If MFN does not offer Diversity in the termination to a Building,
the Building Access Payment for that Building shall be reduced by [***] (for a
total of [***] for the first year) until such time as Diversity is provided, if
ever.

         (d) Williams may cancel a Building after 12 months of Building Access
Payments for such Building by providing at least 30 days prior written notice to
MFN.

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         (e) The parties agree that MFN may splice up to a full ribbon of cable
at each Building even if Lessee requests interconnection of less than 12 fibers.
Lessee is not obligated to pay the Building Access Payment for any extra fibers
spliced over and above the number of fibers ordered, and Lessee may still port
such fibers under Section 3.1.

4.3. NON-RECURRING CHARGES. Upon Product Order execution, MFN will invoice and
Lessee agrees to pay non-recurring charges agreed upon in the Product Order.
Non-recurring charge will include:

         (a) MFN's Costs associated with splicing, testing and/or constructing
laterals at Buildings provided pursuant to Section 3.4:

         (b) Intra-building riser cabling and construction pursuant to Section
5.6; and

         (c) MFN's Costs associated with Splice Point interconnection pursuant
to Section 9.2.

4.4 ADDITIONAL CHARGES. MFN will invoice and Lessee agrees to pay for all other
additional fees and charges contemplated by this Agreement or set forth in a
signed Product Order for services.

4.5. PAYMENT TERMS. Building Access Payments and Lease Payments commence on the
first day of the month beginning with the month after the Acceptance Date of the
relevant Lessee Fiber and/or Building, except that the first payment shall
include payment from the Acceptance Date to the last day of the month during
which the Acceptance Date occurs, as well as payment for the first full month
after the Acceptance Date. Lessee shall continue making such payments through
the first day of the month in which the Term expires, unless earlier terminated
as herein provided. All payments are payable in accordance with Article 11.

4.6 NO BUILDING ACCESS PAYMENTS AT POPS. MFN will not charge a Building Access
Payment for termination within MFN POPs where Lessee is collocating with MFN, or
at Lessee's POPs. Lessee will pay other recurring charges and nonrecurring
charges associated with services rendered by MFN at MFN POPs. In addition,
provided that Lessee is making Building Access Payments in connection with any
Building, Lessee shall have the right to route other interconnections through
the Demarcation Point for such Building without paying any additional Building
Access Payment. To be sure, however, MFN is not obligated to provide Williams
with any intra-building riser fiber to facilitate Lessee's other
interconnections.

                       ARTICLE 5. DELIVERY AND ACCEPTANCE

5.1 DELIVERY. MFN will use commercially reasonable efforts to deliver the Lessee
Fiber and Buildings by the date stated in a Product Order. In the event MFN
anticipates a failure to deliver all or a portion of the Lessee Fiber or
Buildings by the scheduled Delivery Dates, the parties will designate
representatives to meet and review the status of the delivery. If the scheduled
Delivery

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Date for any segment of Lessee Fiber or a Building is in fact delayed, such
delay will be considered a triggering event for the accrual of liquidated
damages to the Lessee as follows:

         (a) Subject to subsections (b), (c) and (d) below, and provided the
delay is not caused in whole or in part by Lessee, Lessee is entitled to a
credit against monthly charges in an amount equal to [***] per fiber mile of the
segment of Lessee Fiber for which the Delivery Date is delayed per month until
such time as such segment is delivered, and a credit against monthly charges in
an amount equal to [******] per delayed Building per month until delivered
("Liquidated Damages");

         (b) Liquidated Damages for each segment of Lessee Fiber is limited to
[***] of the present value of the total monthly charges payable based on
[******] per fiber mile (using a discount factor of [***]) associated with the
fiber miles for the delayed segment.
[*******************************************************************************
********************************************************************************
********************************************************************************
****************************************************]Partial months of delay
will be credited on a daily pro-rated basis;

         (c) Liquidated Damages for Lessee Fiber for all delays are limited to
[***] of the then-current monthly invoicing of [******] per fiber mile to
Lessee. As an example, if MFN is currently billing Lessee [*******] per month,
Lessee is entitled to a maximum of [*******] per month in Liquidated Damages,
regardless of the number of delayed segments;

         (d) Lessee may terminate the Agreement with respect a delayed segment
of Lessee Fiber or a delayed Building upon 15 days prior written notice to MFN,
unless and until delivery actually occurs. Upon termination, Liquidated Damages
will cease to accrue for the terminated segments and/or Buildings, and MFN has
no further payment obligations with respect to such segment.

The parties agree that the Liquidated Damages represent a reasonable estimate of
anticipated damages incurred by Lessee in the event of a delay of a segment of
Lessee Fiber or a Building. The Liquidated Damages and termination of a segment
with a reduction of payment obligations are the sole and exclusive remedies of
the Lessee and the sole and exclusive liabilities of MFN with respect to a
delivery delay, and provided each party has complied with the terms of this
Section 5.1, under no circumstances will a delay in the Delivery Date for a
segment of Lessee Fiber or a Building be considered a default.

5.2 OBLIGATION TO PROVIDE COMPLETION NOTICE. MFN shall promptly notify Lessee in
writing of the date upon which MFN has completed connecting a Building.

5.3 ACCEPTANCE AND TESTING OF FIBERS

         (a) MFN TESTING. MFN shall give notice to Lessee at least 21 days prior
to the date MFN intends to begin testing of Lessee Fiber ("Fiber Acceptance
Testing"). Lessee shall have the right, but not the obligation, to have a
representative present at such Fiber Acceptance Testing.

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MFN shall perform Fiber Acceptance Testing of the Lessee Fiber and provide test
deliverables to Lessee in accordance with Exhibit A. The provisions of this
Subsection 5.3 are intended to apply to the delivery of Lessee Fiber and the
delivery of Buildings and the Acceptance Date for both are conditioned on the
acceptance of such test results.

         (b) OBJECTIONS TO TEST RESULTS. Lessee shall have 21 calendar days
after receipt of test deliverables to provide MFN written notice of any bona
fide determination by Lessee that the Lessee Fiber does not meet the Fiber
Testing Specifications. Such notice shall identify the specific data that
indicate a failure or other specific reasons that such Lessee Fiber fail to meet
the Fiber Testing Specifications.

         (c) RESPONSE TO OBJECTIONS. Upon receiving written notice from Lessee
pursuant to Section 5.3(b), MFN shall either: (i) expeditiously take such action
as shall be reasonably necessary to cause such portion of the Lessee Fiber to
meet the Fiber Testing Specifications and then re-test the Lessee Fiber in
accordance with the provisions of this Article; or (ii) provide Lessee written
notice that MFN disputes Lessee's determination that the Lessee Fiber does not
meet the Fiber Testing Specifications. After taking corrective actions and
re-testing the Lessee Fiber, MFN shall provide to Lessee a copy of the new test
deliverables and Lessee shall again have all rights provided in this Article
with respect to such new test deliverables. The cycle described above of
testing, taking corrective action and re-testing shall take place until the
Lessee Fiber is accepted.

         (d) INDEPENDENT TESTING. If MFN provides notice to Lessee pursuant to
Subsection 5.3(c)(ii), Lessee shall within five calendar days of such notice
designate by written notice to MFN the names and addresses of three reputable
and independent fiber optic testing companies. MFN shall designate one of such
companies to conduct an independent re-test of the Lessee Fiber for the relevant
Lessee Fiber. If, after such re-testing, the testing company determines that the
Lessee Fiber so tested: (i) meet the Fiber Testing Specifications, then Lessee
shall pay the testing company's charges for performing the testing and the
Acceptance Date for the relevant Lessee Fiber shall be 21 calendar days after
the date that MFN originally provided its test deliverables; or (ii) do not meet
the Fiber Testing Specifications, then MFN shall pay the testing company's
charges for performing the testing and shall perform the corrective action and
re-testing set forth in Subsection 5.3(c)(i).

5.4 ACCEPTANCE. Unless Lessee provides a timely written objection pursuant to
Section 5.3, the Acceptance Date for each delivery occurs on the twenty-first
calendar day after Delivery Date, or, if earlier, the date Lessee (a) provides
written acceptance of the Lessee Fiber or Building or (b) commences use of the
Lessee Fiber or Building. Any failure by Lessee to accept or reject the Lessee
Fiber within the 21-day period, or any use of the Lessee Fiber by Lessee Fiber
for any purpose other than testing, constitutes acceptance for purposes of this
Agreement #2 and Lessee is deemed to have accepted upon such use or on the 22nd
day after the Delivery Date.

5.5 AS-BUILT DRAWINGS. MFN will provide, within 180 days of the Acceptance Date,
to Lessee as-built drawings of Lessee Fiber in the format described in Exhibit C
to this Agreement.

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5.6 INTRABUILDING EXTENSIONS. Lessee may elect to obtain either fiber optic or
metallic (e.g., coaxial cable or copper twisted pair) extensions between a MFN
Demarcation Point at a Building and another point within the same Building. Upon
written request for either such extension setting forth the design and
terminating location of such extension, MFN shall, at its sole discretion and in
accordance with its then-standard order intervals, either (a) construct a
Lessee-owed riser for a nonrecurring charge equal to its Cost; (b) designate at
least one, but up to three, reputable MFN-approved contractors authorized to
perform such work, in which case MFN shall have no responsibility for such
extension and Lessee shall deal directly with any such contractor for
Lessee-owned risers; or (c) provide MFN-owned riser at MFN's then-current
charge. MFN shall reasonably cooperate with any such approved contractors
selected by Lessee to allow them to perform such work.

5.7 USE OF PARTIALLY COMPLETED SEGMENT. If MFN has not delivered a segment or
ring of Lessee Fiber by the scheduled Delivery Date, but some portions of the
segment are available for use, MFN shall, upon request of Lessee, permit Lessee
to use such available portions and Lessee shall pay a pro rata share of the
lease payment with respect to the Lessee Fiber in such segment. In addition, in
the event that Lessee elects to accept a portion of a segment of Lessee Fiber
prior to the time that a complete segment or ring is available for use, the late
fee payment set forth in Section 5.1 shall be reduced in proportion to the
Lessee Fiber in the segment or ring being utilized.

5.8 EARLY DELIVERY. In the event that MFN has any Lessee Fiber available prior
to the scheduled Delivery Date, MFN may give notice to Lessee, offering to
deliver such Lessee Fiber prior to the scheduled Delivery Date therefore. Lessee
shall advise MFN whether or not Lessee desires to begin using such Lessee Fiber
prior to the scheduled Delivery Date. If Lessee elects to begin such use prior
to the scheduled Delivery Date, the Term of such Lessee Fiber and payment
obligations shall commence upon the actual Acceptance Date thereof.

                     ARTICLE 6. COLLOCATION AND MAINTENANCE

Collocation, operation and maintenance of the Lessee Fiber is governed by the
Collocation and Maintenance Agreement, dated contemporaneously with this
Agreement #2.

                            ARTICLE 7. AUTHORIZATIONS

7.1 MAINTAINING AUTHORIZATIONS. MFN shall use commercially reasonable efforts to
maintain, renew, or replace the Right-of-Way Authorizations during the Term. If
MFN determines it is not commercially reasonable to maintain, renew or replace
any of its existing Right-of-Way Authorizations during the Term, then MFN shall
give notice to Lessee and shall cooperate with Lessee, at Lessee's written
request, to attempt to maintain, renew or replace such Right-of-Way
Authorizations, at Lessee's sole Cost. During the last three years of the Term,
upon written notice from Lessee requesting such information, MFN shall promptly
provide written notice of the status (including any potential or pending
terminations or expirations) of Right-of-Way Authorizations

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relating to the Lessee Fiber, including but not limited to whether or not MFN
intends to extend or renew any Right-of-Way Authorizations. In the event that
during the Term any Right-of-Way Authorization expires or is terminated and is
not replaced, Lessee shall have the right upon 30 days prior written notice to
MFN, to terminate the Lease with respect to the Lessee Fiber affected by such
expired or terminated Right-of-Way Authorization. Upon such termination,
Lessee's obligation to make any Lease payments with respect to which the Lease
has been terminated shall expire.

7.2 EXTENSION OF LEASE TERM. To the extent MFN has elected to maintain or extend
or replace Right-of-Way Authorizations with respect to this Lease beyond the
Term, Lessee may request an extension of the Term of such Lease, and MFN agrees
to negotiate with Lessee with respect to such extension, but MFN shall have no
obligation to grant any such extension.

                        ARTICLE 8. INTENTIONALLY OMITTED

                  ARTICLE 9. INTERCONNECTION OF LESSEE'S SYSTEM

9.1 GENERAL. After the Effective Date, Lessee has the right but not the
obligation to request additional Buildings to be interconnected with the Lessee
Fiber.

9.2 SPLICE POINTS. Except as limited by Section 9.3, MFN will provide Lessee
with access to the MFN System backbone at mutually agreed upon
manholes/handholes ("Splice Point(s)") for the purpose of interconnecting a
Lessee-owned lateral connection to the Lessee Fiber. Upon acceptance of Lessee's
request for a Splice Point, MFN, in its reasonable discretion, will select the
closest serving manhole or handhole. Lessee must provide and install
Lessee-owned manholes/handholes and/or conduit to the selected MFN
manhole/handhole for Splice Point interconnection. MFN or an MFN-approved
contractor will perform all interconnection work, including penetration of the
MFN manholes/handholes, installation of the conduit, and pulling and maintaining
the fiber optic cable between Lessee's facilities and the selected MFN
manhole/handhole. All work in MFN manholes/handholes and splice enclosures,
including splicing and manhole/handhole penetration, will be managed and
supervised by MFN. MFN will then provide a ribbon tie cable between Lessee's
facilities and MFN's selected manhole/handhole, and each party will perform
splicing in its own manhole/handhole. MFN will invoice and Lessee agrees to pay
all Costs associated with MFN's provision of Splice Points including the cost of
the ribbon tie cable. MFN shall allow Lessee to connect at agreed upon Splice
Points at any time during the Term at no cost to Lessee other than those
provided hereinabove.

9.3 DATA CENTER ACCESS. MFN Data Center Access is restricted to Lessee's
provision of dedicated private line transport services to Lessee's customers.
Under no circumstances is Lessee permitted to sell IP transit services or
dedicated dark fiber transactions that originate or terminate in an MFN Data
Center, unless allowed by a separate agreement. MFN reserves the right to
inspect Lessee's use of a MFN Data Center at any time, 24 hours per day, after
reasonable notice to Lessee. Any violation of this section is deemed a material
breach of the Agreement. Nothing herein shall

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restrict Lessee from providing any and all services to Lessee customers in
separate space located outside or within the same building as the MFN Data
Center.

Collocation within a MFN Data Center is pursuant to separate collocation license
agreement executed between the Parties.

9.4 DEMARCATION POINT.

         (a) BUILDINGS. The Demarcation Point for a Building shall be at:

                  (i) MFN's fiber patch panel, the DSX-N panel (as designated by
         MFN), a splice enclosure in the basement or MFN closest serving manhole
         serving the Building; provided, however, that MFN agrees to provide
         conduit connectivity to Lessee at all non-ILEC Buildings; or

                  (ii) the demarcation point mandated by the agreement between
         Lessor and the ILEC; and, to the extent Lessor is later allowed to
         install or access a fiber patch panel or DSX-N panel inside of the
         Building, such point shall become the Demarcation Point if mutually
         agreeable and Lessor agrees to deliver Lessee's Fiber to such point.

         (b) SPLICE POINTS. The Demarcation Point for each Splice Point is at
the Lessee-provided manhole/handhole unless otherwise agreed upon by the
parties.

9.5 ADDITIONAL LIMITATIONS ON INTERCONNECTION RIGHTS. Lessee's exercise of the
interconnection right set forth in Section 9.1 shall be subject to any
prohibitions or restrictions in MFN's Right-of-Way Authorizations. Lessee may
not establish an interconnection that MFN, in its reasonable discretion (applied
without unreasonable discrimination with respect to interconnections made by MFN
or third parties), determines is likely to materially and adversely affect the
MFN System.

9.6 FACILITIES OWNERSHIP AND CONTROL. Lessee shall retain ownership of any
portion of facilities on its side of the Demarcation Point during the Term of
this Agreement #2 and MFN shall have no obligation to maintain, repair,
relocate, or monitor such Lessee facilities (including any fiber drop facilities
established pursuant to Section 9.3). Lessee shall not access a splice, splice
box, splice vault, or similar facility interconnecting with MFN's System. MFN
shall perform any work required with respect to such splice facilities and may
invoice Lessee for the Cost of performing such work at the request of Lessee
(except to the extent the work relates to the termination in a Building included
in an executed Product Order).

9.7 LESSEE RESPONSIBILITY. Subject to the provisions herein, Lessee shall be
responsible for obtaining the rights required and for all costs of:

         (a) obtaining rights of way within or beyond MFN's Right-of-Way
Authorizations;

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         (b) obtaining building access, entry rights, ducts, or riser cables to
interconnect in buildings or any access beyond MFN's Demarcation Point with
respect to a Building;

         (c) providing all Equipment and MFN-approved materials to construct and
install each interconnection, including cables and conduit and any labor charges
associated therewith; and

         (d) bringing facilities to and connecting them with MFN's System.

9.8 THIRD PARTY RELATIONS. If necessary, and where applicable, MFN shall assist
Lessee, at Lessee's Cost, in obtaining from any land or building owner, MFN, or
private or governmental right-of-way owner, any rights required to access and
exit interconnection points. Lessee shall use reasonable efforts to avoid
damaging the relationships between MFN and such third parties.

                       ARTICLE 10. USE OF THE LESSEE FIBER

10.1 OBLIGATION TO COMPLY WITH LAWS; EXCLUSIVE USE. Lessee shall comply in all
material respects with all applicable government codes, ordinances, laws, rules,
regulations, Right-of-Way Authorizations and/or restrictions in its use of MFN's
System. Subject to Article 20, Lessee may use the Lessee Fiber for any lawful
telecommunications purpose. MFN shall have no right to use Lessee Fiber during
the Term of this Agreement #2.

10.2 SYSTEM DAMAGE. MFN and Lessee shall promptly notify each other of any
matters pertaining to any damage or impending damage to or loss of the MFN
System that are known to such party. Lessee shall take all commercially
reasonable precautions against, and shall assume liability, subject to the terms
herein, for, any damage caused by it to the MFN System. Lessee shall not use the
Lessee Fiber in a way that interferes in any material way with or materially
adversely affects the use of any fibers of MFN or the MFN System.

10.3 REGULATORY COOPERATION. Each party shall cooperate with and support the
other in complying with any requirements applicable to the MFN System imposed by
any governmental or regulatory agency or authority.

10.4 LIENS. Lessee shall not cause or permit any part of the MFN System to
become subject to any mechanics lien, materialmans lien, vendors lien, or any
similar lien whether by operation of law or otherwise. If Lessee breaches its
obligations under this Section, it shall immediately notify MFN in writing,
shall promptly cause such lien to be discharged and released of record without
cost to MFN, and shall indemnify MFN against all costs and expenses (including
reasonable attorney's fees and court costs at trial and on appeal) incurred in
discharging and releasing such lien.

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                            ARTICLE 11. PAYMENT TERMS

11.1 TIME AND METHOD OF PAYMENT. Monthly payments for Lessee Fiber and Building
Access shall be made by wire transfer, to the account designated on the invoice
of MFN, within thirty (30) business days of the delivery of such invoice. Except
as otherwise set forth in this Agreement #2, all other amounts due hereunder
shall be paid within 30 calendar days of the invoice delivery date. Except as
otherwise provided, payments may be made by check or draft of immediately
available funds delivered to the address designated in writing by the other
party (e.g., in a statement or invoice) or, failing such designation, to the
address for notice provided pursuant to Section 15.1. Except as set forth
herein, a party may issue an invoice after incurring any costs subject to
reimbursement by the other party or after the time period during which a charge
accrues.

11.2 LATE PAYMENT CHARGES. If Lessee fails to make any payment under this
Agreement #2 when due, such unpaid amounts shall accrue interest, from the date
such payment is due until paid, including accrued interest, at the lower of
eighteen percent (18%) annual interest or the highest percentage allowed by law.

11.3 MONTHLY NETTING AGREEMENT. Notwithstanding anything to the contrary
contained herein, that certain Monthly Netting Agreement between the parties
dated October 30, 2001 shall govern payments made under this Agreement during
the term of such Monthly Netting Agreement.

                           ARTICLE 12. INDEMNIFICATION

12.1 INDEMNITY OBLIGATION. Each party shall indemnify, defend, protect and hold
harmless the other party, its employees, officers, directors, agents,
shareholders, affiliates, Facility Owners/Lenders, and other parties to
Right-of-Way Authorizations that are entitled to indemnity by such indemnifying
party, from and against, and assumes liability for:

         (a) Any injury, loss or damage to any person, tangible property or
facilities of any person or entity (including reasonable attorney's fees and
costs), to the extent arising out of or resulting from the acts or omissions,
negligent or otherwise, of the indemnifying party, its officers, employees,
servants, affiliates, agents or contractors in connection with its performance
under this Agreement #2; and

         (b) Any claims, liabilities or damages arising out of any violation by
the indemnifying party of regulations, rules, statutes or court orders of any
local, state or federal governmental agency, court or body in connection with
its performance under this Agreement #2.

12.2 NO LIMITATION ON CLAIMS AGAINST OTHER PARTIES. Except as set forth herein,
and subject to the terms of any underlying agreements between MFN and any third
person, nothing contained herein shall operate as a limitation on the right of
either party hereto to bring an action for damages against any third person,
including indirect, special or consequential damages, based on any acts or
omissions of such third person as such acts or omissions may affect the
construction, operation or

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use of the Lessee Fiber; provided, however, that each party hereto shall assign
such rights of claims, execute such documents and do whatever else may be
reasonably necessary to enable the other party to pursue any such action against
such third person.

                              ARTICLE 13. INSURANCE

13.1 OBLIGATION TO OBTAIN. During the Term of this Agreement #2, the parties
shall each obtain and maintain not less than the following insurance:

         (a) Commercial General Liability Insurance, including coverage for
sudden and accidental pollution legal liability, with a combined single limit of
$10,000,000 for bodily injury and property damage per occurrence and in the
aggregate; provided that such coverage may be obtained through a combination of
specific and umbrella or excess liability policies.

         (b) Worker's Compensation Insurance in amounts required by applicable
law and Employers Liability Insurance with limits not less than $1,000,000 each
accident. If a party is to perform work in Nevada, North Dakota, Ohio,
Washington, Wyoming, or West Virginia, the party shall participate in the
appropriate state fund(s) to cover all eligible employees and provide a stop gap
endorsement.

         (c) Automobile Liability Insurance with a combined single limit of
$2,000,000 for bodily injury and property damage per occurrence, to include
coverage for all owned, non-owned, and hired vehicles; provided that such
coverage may be obtained through a combination of specific and umbrella or
excess liability policies.

The limits set forth above are minimum limits and shall not be construed to
limit the liability of either party.

13.2 POLICY REQUIREMENTS. Each party shall obtain and maintain the insurance
policies required above with companies rated A- or better by Best's Key Rating
Guide or with a similar rating by another generally recognized rating agency.
The other party, its Affiliates, officers, directors, and employees, and any
other party entitled to indemnification hereunder shall be named as additional
insureds to the extent of such indemnification. Each party shall provide the
other party with an insurance certificate confirming compliance with the
insurance requirements of this Article. The insurance certificate shall indicate
that the other party shall be notified not less than 30 calendar days prior to
any cancellation or material change in coverage. If either party provides any of
the foregoing coverages through a claims made policy basis, that party shall
cause such policy or policies to be maintained for at least three years beyond
the expiration of this Agreement #2.

13.3 WAIVER OF SUBROGATION. The parties shall each obtain from the insurance
companies providing the coverages required by this Agreement #2 a waiver of all
rights of subrogation or recovery in favor of the other party and, as
applicable, its members, managers, shareholders,

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Affiliates, assignees, officers, directors, and employees or any other party
entitled to indemnity under this Agreement #2 to the extent of such indemnity.

13.4 BLANKET POLICIES; SELF-INSURANCE. Nothing in this Agreement #2 shall be
construed to prevent either party from satisfying its insurance obligations
pursuant to this Agreement #2 (a) under a blanket policy or policies of
insurance that meet or exceed the requirements of this Article or (b) with
respect to the insurance required in Sections 13.1(b) and (c), with the consent
of the other party, which consent shall not be unreasonably withheld,
self-insurance.

            ARTICLE 14. TAXES AND FRANCHISE, LICENSE AND PERMIT FEES

14.1 OBLIGATIONS TO PAY RIGHT-OF-WAY CHARGES AND TAXES. The parties acknowledge
that a material premise of this Agreement #2 is that during the Term, MFN shall
obtain, and use commercially reasonable efforts to maintain, its Right-of-Way
Authorizations at its own cost. MFN shall timely pay any and all (a) taxes,
franchise, license and permit fees based on the physical location of the MFN
System, and/or the construction thereof in or on public roads, highways or
rights-of-way; and (b) Right-of-Way Authorization payments applicable to the
System. Notwithstanding the foregoing, Lessee shall pay any taxes, franchise,
license and permit fees based upon its Lease or use of Lessee Fiber. Failure to
pay such taxes or payments by the party responsible therefore, which continues
after seven (7) calendar days written notice thereof by the other party, shall
authorize, but not obligate, the other party to make such payments and
responsible party shall reimburse the other party for such payments promptly
upon demand together with interest at the rate set forth in Section 14.2 from
the date that the other party made such payment until reimbursed by the
responsible party.

14.2 OBLIGATION TO TIMELY PAY TAXES BASED ON REVENUES. Except as set forth in
Section 14.1, Lessee shall pay any and all sales, use, income, gross receipts or
other taxes assessed based upon revenues Lessee receives due to its use of the
Lessee Fiber.

14.3 RIGHT TO CONTEST TAXES. Notwithstanding any provision herein to the
contrary, a party shall have the right by appropriate proceedings brought in
good faith to protest the imposition and/or amount of any taxes or franchise,
license or permit fees imposed on or assessed against it. In such event, the
protesting party shall indemnify and hold the other party harmless from any
expense, legal action or cost, including reasonable attorney's fees, resulting
from the protesting party's exercise of its rights hereunder.

14.4 PROHIBITION ON AGREEMENT AFFECTING OTHER PARTY. Without the prior consent
of Lessee, MFN shall not enter into any agreement that would have the effect of
obligating Lessee to pay additional taxes or franchise, license or permit fees
unless such agreement is required by a government or agency thereof in
connection with the grant of a franchise, license, permit or similar
governmental requirement or required pursuant to a Right-of-Way Authorization.

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                               ARTICLE 15. NOTICE

15.1 ADDRESSES. Unless otherwise provided herein, all notices and communications
concerning this Agreement #2 shall be addressed to the other party as follows:

If to Lessee:              Williams Communications, LLC
                           Attn: Contract Management
                           One Technology Center, TC-6H
                           Tulsa, Oklahoma 74103
                           Facsimile:  (918) 547-0460

with a copy to:            Williams Communications, LLC
                           Attn:   IRU Administration
                           One Technology Center, TC-8A
                           Tulsa, OK 74103
                           Facsimile:  (918) 547-2914

and                        Williams Communications, LLC
                           Attn: General Counsel
                           One Technology Center, TC-15A
                           Tulsa, Oklahoma 7415
                           Facsimile:  (918) 547-2630

If to MFN:                 Metromedia Fiber Network Services, Inc.
                           360 Hamilton Avenue
                           White Plains, New York 10601
                           Attn:  President
                           Facsimile:  (914) 421-7550

With a copy to:            Metromedia Fiber Network Services, Inc.
                           360 Hamilton Avenue
                           White Plains, New York 10601
                           Attn:  General Counsel
                           Facsimile:  (914) 421-6793

or at such other address as may be designated in writing to the other party (a
party may designate a separate address for delivery of invoices).

15.2 METHOD FOR DELIVERING NOTICES AND INVOICES. Unless otherwise provided
herein, notices and invoices shall be in writing and sent by registered or
certified U.S. Mail, postage prepaid, or by commercial overnight delivery
service, or by facsimile, and shall be deemed served or delivered to the
addressee or its office on the date of receipt acknowledgment, or if by
facsimile, upon confirmation of transmission or if postal claim notices are
given, on the date of its return marked

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"unclaimed," provided, however, that upon receipt of a returned notice marked
"unclaimed," the sending party shall make reasonable effort to contact and
notify the other party by telephone.

                    ARTICLE 16. CONFIDENTIALITY AND PUBLICITY

16.1 CONFIDENTIAL INFORMATION. The terms and conditions of this Agreement #2 and
all documents referenced herein, communications between the parties regarding
this Agreement #2, information provided in connection with or pursuant to this
Agreement #2 or the service to be provided hereunder, as well as any financial
or business information of either party are confidential ("Confidential
Information"). Such Confidential Information shall be held in confidence, and
the receiving party shall afford such Confidential Information the same care and
protection as it affords generally to its own Confidential Information (which in
any case shall be not less than reasonable care) to avoid disclosure to or
unauthorized use by any third party. All Confidential Information shall remain
the property of the disclosing party, shall be used by the receiving party only
for its intended purpose, and such Confidential Information, including all
copies thereof, shall be returned to the disclosing party or destroyed after the
receiving party's need for it has expired or upon the request of the disclosing
party. Confidential Information shall not be reproduced except to the extent
necessary to accomplish the purposes and intent of this Agreement #2, or as
otherwise may be permitted in writing by the disclosing party. Notwithstanding
anything contained herein to the contrary, neither party shall be required to
keep confidential any information that (a) becomes publicly available other than
through the actions or omissions of the receiving party; (b) is required to be
disclosed pursuant to a governmental or judicial rule, order or regulation; (c)
the recipient of the Confidential Information independently develops; (d)
becomes available to the receiving party without restriction from a third party;
(e) is required by its lender and is given to such lender on a confidential
basis; or (f) is subject to "due diligence" review by a potential acquirer of a
significant equity interest in it or its ultimate or intermediate parent company
(a significant equity interest shall be an interest of at least 5% of the voting
equity of a party or of securities having a market value of at least $100
million) and is given to such potential acquirer on a confidential basis.

16.2 PUBLICITY. Following the Effective Date, the parties shall coordinate and
cooperate with each other when making public announcements or disclosures to any
governmental entities related to the terms of this Agreement #2 and each party
shall have the right to promptly review, comment upon and approve (such approval
not to be unreasonably withheld or delayed) any publicity materials, press
releases or other public statements or disclosures to governmental entities by
the other party that refer to, or that describe any aspect of this Agreement #2;
provided, however, that no party shall have an approval right with respect to
any public announcements or disclosures to any governmental entities which are,
in the reasonable judgment of the party making such public announcement or
disclosure, required by law.

                               ARTICLE 17. DEFAULT

17.1 PARTIAL TERMINATION UPON DEFAULT. Either party, upon written notice to the
other party after the other party's default and the other party's failure to
cure any default in the performance of any

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material obligation hereunder prior to the end of the applicable cure period,
may terminate this Agreement #2 as herein provided, provided that at the time of
termination such default remains uncured:

         (a) MFN may terminate this Agreement #2, to the extent that Lessee is
the defaulting party; and/or

         (b) Lessee may terminate this Agreement #2, to the extent that the
default relates to the MFN System (or, at Lessee's election, with respect to any
Lessee Fiber for which the Acceptance Date has not occurred as provided in
Article 5), if MFN is the defaulting party.

17.2 SPECIFIC DEFAULT EVENTS. Events of default shall include but not be limited
to: (a) the making of a general assignment for the benefit of the defaulting
party's creditors; (b) the filing of a voluntary petition in bankruptcy or the
filing of a petition in bankruptcy or other insolvency protection against the
defaulting party which is not dismissed within 90 calendar days thereafter; (c)
the filing by the defaulting party of any petition or answer seeking, consenting
to, or acquiescing in reorganization, arrangement, adjustment, composition,
liquidation, dissolution, or similar relief; (d) any violation by Lessee of the
restrictions set forth in Section 20.3.

17.3 CURE PERIOD. The cure period applicable to Section 17.1 shall be:

         (a) with respect to a default in payment, the period ending ten (10)
business days after a written notice of such default is given;

         (b) with respect to any other default, the period ending 30 calendar
days after a written notice of such default is given, provided, however, that if
such default cannot with reasonable diligence be cured within such 30-day
period, and such other party has commenced to effect a cure immediately upon
receipt of such notice, and diligently pursues such cure, then such cure period
will be extended for a period reasonably required to cure such default but in no
event more than an additional 30 calendar days.

17.4 FAILURE TO CURE. Upon the failure by the defaulting party to timely cure
any such default after notice thereof from the other party, the other party may,
subject to the provisions of Section 19, take such action as it determines, in
its sole discretion, to be necessary to correct the default, and pursue any
legal remedies it may have under this Agreement #2, applicable law, or
principles of equity relating to such breach.

17.5 WAIVER OF SPECIFIC DEFAULTS. Any event of default by the defaulting party
may be waived under the terms of this Agreement #2 at the other party's option.
Any such waiver shall be in writing.

17.6 DISPUTED AMOUNTS. Notwithstanding the other provisions of this Article,
failure to pay an amount subject to a bona fide dispute shall not be an event of
default (until such dispute is resolved

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pursuant to Article 19 or otherwise) to the extent the disputed amount is (a)
less than $100,000 or (b) paid into an escrow account of a nationally chartered
domestic bank with offices in New York pending resolution of the dispute. The
interest rate set forth in Section 11.2 shall apply to amounts so withheld or
paid into escrow by one party and later awarded to the other party, but the
party paying such amounts into escrow shall, upon closing of an escrow account,
be entitled to any interest received from, and responsible for paying any fees
charged by, the bank holding the escrow funds.

                            ARTICLE 18. FORCE MAJEURE

         Neither party shall be in default under this Agreement #2 with respect
to any delay in such party's performance (other than the payment of monetary
amounts due under this Agreement #2) caused by any of the following conditions:
act of God, fire, flood, material shortage or unavailability not resulting from
the responsible party's failure to timely place orders therefore, lack of
transportation, government codes, ordinances, laws, rules, regulations or
restrictions, war or civil disorder, or any other cause beyond the reasonable
control of such party, provided that the party claiming relief under this
Section shall promptly notify the other in writing of the existence of the event
relied on and the cessation or termination of said event. The party claiming
relief under this Section shall exercise commercially reasonable efforts to
minimize the time for any such delay.

                             ARTICLE 19. ARBITRATION

19.1 OBLIGATION TO ARBITRATE. Any dispute or disagreement relating to this
Agreement #2 or any matter arising between Lessee and MFN in connection with
this Agreement #2 which is not settled to the mutual satisfaction of Lessee and
MFN within 30 calendar days from the date that either party informs the other in
writing that such dispute or disagreement exists, shall be settled by
arbitration by a single arbitrator in Chicago, Illinois, in accordance with the
Commercial Arbitration Rules of the American Arbitration Association in effect
on the date that such notice is given. If the parties are unable to agree on a
single arbitrator within fifteen calendar days, the American Arbitration
Association shall select an arbitrator. The decision of the arbitrator shall be
final and binding upon the parties and shall include written findings of law and
fact, and judgment may be obtained thereon by either party in a court of
competent jurisdiction. Each party shall bear the cost of preparing and
presenting its own case. The cost of the arbitration, including the fees and
expenses of the arbitrator, shall be shared equally by the parties unless the
award otherwise provides.

19.2 EXCEPTIONS TO ARBITRATION OBLIGATION. The obligation herein to arbitrate
shall not be binding upon any party with respect to requests for preliminary
injunctions, temporary restraining orders or other procedures in a court of
competent jurisdiction to obtain interim relief when deemed necessary by such
court to preserve the status quo or prevent irreparable injury pending
resolution by arbitration of the actual dispute.

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                             ARTICLE 20. ASSIGNMENT

20.1 RESTRICTIONS ON ASSIGNMENT. Except as provided in the second sentence of
this Section, neither party shall assign or otherwise transfer this Agreement #2
or its rights or obligations hereunder to any other party without the prior
written consent of the other party, which consent shall not be unreasonably
withheld or delayed. Either party shall have the right, without the other
party's consent, to assign or otherwise transfer this Agreement #2 in whole or
in part as collateral to any lender or to any of its Affiliates or to any
corporation into which it may be merged or consolidated or which purchases all
or substantially all of its assets.

20.2 AGREEMENT #2 BINDS SUCCESSORS. This Agreement #2 and each of the party's
respective rights and obligations under this Agreement #2, shall be binding upon
and shall inure to the benefit of the parties hereto and each of their
respective successors and permitted assigns. Any assignment or transfer shall be
subject to the other party's rights under this Agreement #2 and any assignee or
transferee shall continue to perform the assigning party's obligations under
this Agreement #2.

20.3     RESTRICTION ON TRANSFER OF DARK FIBER RIGHTS. [************************
********************************************************************************
********************************************************************************
*********************************************************]

20.4 FINANCING ARRANGEMENTS. Either party shall have the right, directly or
through an Affiliate, to enter into financing arrangements (including secured
loans, leases, sales with lease-back, or leases with lease-back arrangements,
purchase-money or vendor financing, conditional sales transactions, or other
arrangements) with one or more financial institutions, vendors, suppliers or
other financing sources that, with respect to MFN, relate to the MFN System and,
with respect to Lessee, relate to Lessee's Lease rights (and not to any property
right in the MFN System or the Lessee Fiber).

                        ARTICLE 21. RULES OF CONSTRUCTION

21.1 GOVERNING LAW. This Agreement #2 shall be deemed a New York agreement and
shall be governed by and construed in accordance with the domestic laws of the
State of New York applicable to New York agreements, without reference to its
choice of law principles.

21.2 INTERPRETATION. The captions or headings in this Agreement #2 are strictly
for convenience and shall not be considered in interpreting this Agreement #2 or
as amplifying or limiting any of its content. Words in this Agreement #2 that
import the singular connotation shall be interpreted as plural, and words that
import the plural connotation shall be interpreted as singular, as the identity
of the parties or objects referred to may require. References to "person" or
"entity" each include natural persons and legal entities, including
corporations, limited liability companies, partnerships, sole proprietorships,
business divisions, unincorporated associations, governmental entities, and any
entities entitled to bring an action in, or that are subject to suit in an
action before, any state or federal court of the United States. Whenever the
words "include," "includes" or "including" are

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used in this Agreement #2, they shall be deemed to be followed by the words
"without limitation." "Days" refers to calendar days, except that references to
"business days" exclude Saturdays, Sundays and holidays during which nationally
chartered banks in New York, New York are authorized or required to close.
Unless expressly defined herein, words having well-known technical or trade
meanings shall be so construed.

21.3 CUMULATIVE REMEDIES. Except as set forth to the contrary herein, any right
or remedy of either party shall be cumulative and without prejudice to any other
right or remedy, whether contained herein or not.

21.4 NO THIRD-PARTY RIGHTS. Nothing in this Agreement #2 is intended to provide
any legal rights to anyone not an executing party of this Agreement #2 except
under the indemnification and insurance provisions and except (a) as set forth
in Sections 22.4 and 23.2 and (b) that the Facility Owners/Lenders shall be
entitled to rely on and have the benefit of Article 23.

21.5 AGREEMENT FULLY NEGOTIATED. This Agreement #2 has been fully negotiated
between and jointly drafted by the parties.

21.6 DOCUMENT PRECEDENCE. In the event of a conflict between the provisions of
this Agreement #2 and those of any Exhibit, the provisions of this Agreement #2
shall prevail and such Exhibits shall be corrected accordingly. In the event of
a conflict between the provisions of this Agreement #2 and Product Order, the
provisions of the Product Order prevail.

21.7 INDUSTRY STANDARDS. Except as otherwise set forth herein, for the purpose
of this Agreement #2 the normal standards of performance within the
telecommunications industry in the relevant market shall be the measure of
whether a party's performance is reasonable and timely.

21.8 CROSS REFERENCES. Except as the context otherwise indicates, all references
to Exhibits, Parts, Schedules, Articles, Sections, Subsections, Clauses, and
Paragraphs refer to provisions of this Agreement #2.

21.9 LIMITED EFFECT OF WAIVER. The failure of either MFN or Lessee to enforce
any of the provisions of this Agreement #2, or the waiver thereof in any
instance, shall not be construed as a general waiver or relinquishment on its
part of any such provision, but the same shall nevertheless be and remain in
full force and effect.

21.10 SEVERABILITY. If any term, covenant or condition in this Agreement #2
shall, to any extent, be invalid or unenforceable in any respect under the laws
governing this Agreement #2, the remainder of this Agreement #2 shall not be
affected thereby, and each term, covenant or condition of this Agreement #2
shall be valid and enforceable to the fullest extent permitted by law.

21.11 NO PARTNERSHIP CREATED. The relationship between MFN and Lessee shall not
be that of partners, agents, or joint venturers for one another, and nothing
contained in this Agreement #2 shall

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be deemed to constitute a partnership or agency agreement between them for any
purposes, including federal income tax purposes. The parties, in performing any
of their obligations hereunder, shall be independent contractors or independent
parties and shall discharge their contractual obligations at their own risk.

21.12 NO REIMBURSEMENT. Unless provided otherwise herein, each party shall
perform its obligations without right of reimbursement or contribution from the
other party.

21.13 RIGHT TO SUBCONTRACT. MFN or the underlying facility owner may subcontract
for any of its obligations hereunder, including splicing, testing, maintenance,
repair, relocation, and restoration services. MFN may fulfill its obligations to
provide Lessee Fiber in its System by constructing, acquiring title to,
acquiring rights in, leasing, entering into financing leases, or otherwise
obtaining a right to use its System or various portions thereof. The use of any
such subcontractor, underlying Lease provider, financing arrangement, or other
arrangement shall not relieve MFN of its obligations hereunder.

21.14 SURVIVAL. No termination or expiration of this Agreement #2, either in
part or in whole, shall affect the rights or obligations of any party hereto:
(i) with respect to any payment hereunder for services rendered prior to the
date of termination; (ii) pursuant to Articles 12, 13, 14, 16, 19, 21, 23, and
24 entitled Indemnification; Insurance; Taxes and Franchise, License, and Permit
Fees; Confidentiality and Publicity; Arbitration; Rules of Construction;
Limitation of Liability; and Audit Rights; respectively; or (iii) pursuant to
other provisions of this Agreement #2 that, by their sense and context, are
intended to survive termination of this Agreement #2.

                   ARTICLE 22. REPRESENTATIONS AND WARRANTIES

22.1 AGREEMENT VALIDITY. Each party represents and warrants that:

         (a) It has the full right and authority to enter into, execute, deliver
and perform its obligations under this Agreement #2;

         (b) It has taken all requisite corporate action to approve the
execution, delivery and performance of this Agreement #2;

         (c) This Agreement #2 constitutes a legal, valid and binding obligation
enforceable against such party in accordance with its terms;

         (d) Its execution of and performance under this Agreement #2 shall not
violate any applicable existing regulations, rules, statutes or court orders of
any local, state or federal government agency, court or body; and

         (e) It has the right pursuant to such party's Right-of-Way
Authorizations to grant the rights to the other party as set forth in this
Agreement #2.

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22.2 ACCEPTANCE DATE REPRESENTATIONS. As of the Acceptance Date for any Lessee
Fiber, MFN represents that:

         (a) MFN or the underlying facility owner for any portion of the Lessee
Fiber shall have obtained all Right-of-Way Authorizations necessary for the
installation and use of the Lessee Fiber hereunder;

         (b) MFN shall have obtained by Lease agreement, lease, or otherwise the
right to use portions of the Lessee Fiber it does not own;

         (c) MFN shall have obtained all Right-of-Way Authorizations for the
Lessee Fiber;

         (d) no Right-of-Way Authorizations for such Lessee Fiber impose
unreasonable limitations or requirements on Lessee's exercise of its rights
under this Agreement #2; and

         (e) the Lessee Fiber has been designed, engineered, installed, and
constructed in accordance with the specifications set forth in Exhibit D and in
compliance with all applicable building, construction and safety codes for such
construction and installation, as well as any and all other applicable
governmental laws, codes, ordinances, statutes and regulations.

22.3 DISCLAIMER OF WARRANTY. EXCEPT AS SPECIFICALLY SET FORTH IN THIS AGREEMENT,
MFN MAKES NO WARRANTY TO LESSEE OR ANY OTHER PERSON OR ENTITY, WHETHER EXPRESS,
IMPLIED, OR STATUTORY, AS TO THE DESCRIPTION, QUALITY, MERCHANTABILITY,
COMPLETENESS OR FITNESS FOR ANY PURPOSE OF ANY FIBERS OR ANY SERVICE PROVIDED
HEREUNDER OR DESCRIBED HEREIN, OR AS TO ANY OTHER MATTER, ALL OF WHICH
WARRANTIES ARE HEREBY EXCLUDED AND DISCLAIMED.

22.4 NO THIRD-PARTY WARRANTIES. NO FACILITY OWNERS/LENDERS HAVE MADE ANY
REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, TO LESSEE CONCERNING
MFN, LESSEE FIBER, THE CABLE, OR THE SYSTEM OR AS TO ANY OF THE MATTERS SET
FORTH IN SECTIONS 22.1 OR 22.2. NO LESSEE LENDERS HAVE MADE ANY REPRESENTATION
OR WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, TO MFN CONCERNING LESSEE, LESSEE
FIBER, THE CABLE, THE MFN SYSTEM OR AS TO ANY OF THE MATTERS SET FORTH IN
SECTIONS 22.1 OR 22.2 OR AS TO ANY OTHER MATTER.

                      ARTICLE 23. LIMITATIONS OF LIABILITY

23.1 RESTRICTION ON TYPES OF LIABILITY. Notwithstanding any provision of this
Agreement #2 to the contrary, in no event shall either party be liable to the
other party for any special, incidental,

                                       24
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indirect, punitive, reliance or consequential damages, whether foreseeable or
not, arising out of, or in connection with this Agreement #2, in tort, breach of
contract, breach of warranty, strict liability or any other cause of action,
including damage or loss of property or equipment, loss of profits or revenue,
cost of capital, cost of replacement services, or claims of customers, whether
occasioned by any repair or maintenance performed by, or failed to be performed
by, the first party or any other cause whatsoever.

23.2 NO RECOURSE AGAINST RELEASED PARTIES. Neither party shall have any recourse
of any kind against any Released Party or any assets of a Released Party under
this Agreement #2, it being expressly agreed and understood that no liability
whatever shall attach to or be incurred by any Released Party under or by reason
of this Agreement #2 or any other instrument, arrangement or understanding
related to Leased Fiber. Each party waives all such recourse to the extent set
forth in this Section on behalf of its successors, assigns, and any entity
claiming by, through, or under such party.

23.3 NO PERSONAL LIABILITY. Each action or claim against any party arising under
or relating to this Agreement #2 shall be made only against such party as a
corporation, and any liability relating thereto shall be enforceable only
against the corporate assets of such party. No party shall seek to pierce the
corporate veil or otherwise seek to impose any liability relating to, or arising
from, this Agreement #2 against any shareholder, employee, officer, director or
agent of the other party. Each of such persons is an intended beneficiary of the
mutual promises set forth in this Section and shall be entitled to enforce the
obligations or provisions of this Section.

                            ARTICLE 24. AUDIT RIGHTS

Each party shall keep such books and records (which shall be maintained on a
consistent basis and substantially in accordance with generally accepted
accounting principles) as shall readily disclose the basis for any charges
(except charges fixed in advance by this Agreement #2 or by separate agreement
of the parties) or credits, ordinary or extraordinary, billed or due to the
other party under this Agreement #2 and shall make them available for
examination, audit, and reproduction by the other party and its agents for a
period of one year after such charge or credit is billed or due. To the extent a
party seeks reimbursement of out-of-pocket costs or services provided on a
per-hour basis, it shall provide reasonable supporting documentation to the
other party.

                    ARTICLE 25. IMPROPER PAYMENTS PROHIBITED

Neither party shall use any funds received under this agreement for illegal or
otherwise "improper" purposes. Neither party shall pay any commission, fees or
rebates to any employee of the other party. If either party has reasonable cause
to believe that one of the provisions in this article has been violated, it, or
its representative, may audit the books and records of the other party for the
sole purpose of establishing compliance with such provisions.

                                       25
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               ARTICLE 26. ENTIRE AGREEMENT; AMENDMENT; EXECUTION

26.1 INTEGRATION; INCORPORATION; MODIFICATION. This Agreement #2 constitutes the
entire agreement and understanding between the parties with respect to the
subject matter hereof and supersedes all prior agreements whether written or
oral relating to the subject matter hereof, which are of no further force or
effect. The Exhibits and Schedules referred to herein are integral parts hereof
and are hereby made a part of this Agreement #2. This Agreement #2 may be
modified or supplemented only by an instrument in writing executed by a duly
authorized representative of each party.

26.2 COUNTERPARTS; EXECUTION. This Agreement #2 may be executed in one or more
counterparts, all of which taken together shall constitute one and the same
instrument. A party may duly execute and deliver this Agreement #2 by execution
and facsimile delivery of the signature page of a counterpart to the other
party, provided that, if delivery is made by facsimile, the executing party
shall promptly deliver a complete counterpart that it has executed to the other
party.

In confirmation of their consent to the terms and conditions contained in this
Agreement #2 and intending to be legally bound hereby, the parties have executed
this Lease Agreement #2 as of the date first above written.

METROMEDIA FIBER NETWORK SERVICES, INC., a Delaware corporation

Signature:          /s/ William G. La Perch
          ----------------------------------------------------

(Print) Name:       William G. La Perch
              ------------------------------------------------

(Print) Title:      President
              ------------------------------------------------

WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability company

Signature:          /s/ Howard E. Janzen
          ----------------------------------------------------

(Print) Name:       Howard E. Janzen
              ------------------------------------------------

(Print) Title:      President & CEO
              ------------------------------------------------

                                       26
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                                    EXHIBIT A

                          FIBER TESTING SPECIFICATIONS

MFN will perform fiber testing, as described below, on each Leased Fiber and
will provide documentation of these test results to the Customer via e-mail.
Each "span" will be defined in documentation included in the Customer's package.
Acceptance of a span by Customer will be an acknowledgement by the Customer that
all Leased Fiber complies with all performance criteria contained herein and
performs within the parameters of the fiber manufacturer's specifications.

1)   POWER TESTING: This end-to-end loss measurement will be conducted for each
     Leased Fiber in the span and from both directions using an
     industry-accepted laser source and power meter. The bi-directional average
     will be used to determine the end-to-end loss of the span at each
     appropriate wavelength. This test will be conducted at both 1310 nm and
     1550 nm for Standard Single Mode Fiber; Dispersion Shifted Fiber (True
     WaveTM, LEAFTM, etc.) will be tested at 1550 nm only. In the event that a
     span consists of both Standard Single Mode and Dispersion Shifted fiber
     types, only 1550 nm testing will be conducted. This power testing will
     ensure fiber continuity and the absence of crossed fibers in the span.
     Power testing will only be conducted where the Leased Fiber is terminated
     by MFN in fiber distribution panels at both ends of the span.

2)   OTDR TESTING: This testing will be conducted at both 1310 nm and 1550 nm
     wavelengths when the Leased Fiber consists of Standard Single Mode Fiber,
     but will be done at 1550 nm only if the Leased Fiber consists of either
     Dispersion Shifted Fiber (True-WaveTM, LEAFTM, etc.) or a combination of
     Single Mode and Dispersion Shifted fiber types.

     OTDR testing will be conducted on a bi-directional basis for each Leased
     Fiber in each span at the appropriate wavelengths for the Leased Fiber
     described above. However, if due to length or attenuation reasons that the
     Leased Fiber span exceeds the dynamic range of an OTDR, a portion or the
     entire span may be tested on a unidirectional basis only. Alternatively,
     the Leased Fiber span may be divided into shorter testing spans, to the
     extent reasonably possible, in order to obtain bi-directional analysis.
     Also, in instances where a Customer intends to accept Leased Fiber that is
     not terminated at one end by MFN in a fiber distribution panel (such as in
     a manhole or handhole) only unidirectional testing will be performed.

     The turnover documentation package delivered to Customer will contain the
     actual traces that detail the testing parameters (including pulse width,
     averaging and range). The average bi-directional splice loss for all
     splices within each span will be of 0.15 dB or less while each connector
     pair (such as at a FDP) will have an average bi-directional loss of 0.5 dB
     or less. (Note that the front and end connector of the span can only be
     measured uni-directionally and will also have a loss equal to or less than
     0.5 dB). In the event that OTDR acceptance testing must be done on a
     unidirectional basis (for reasons described above), an average per span
     splice loss will be 0.30 dB.

     If the average bi-directional splice loss of each span exceeds 0.15 dB (or
     0.30 dB uni-directionally), MFN will provide upon the Customer's request
     documentation of at a least three attempts to reduce this value to below
     0.15 dB (0.30 dB uni-directionally). The only exception to this will be in
     the instance of a splice between two different fiber types (Standard
     Single-mode to Dispersion Shifted, Depressed-Clad to Matched Clad, fibers
     with different mode-field diameters).

Customer should also note that the loss and/or reflectance of the front-end
connector (as measured using a launch cord) is only an indicator of a problem
such as a defective port, bulkhead, or the like. Since a different patch cord
will be used by Customer (that connects to their equipment, for example) to mate
to this connector, a different loss and/or reflectance may occur.

Exhibit A - Page 1
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                                    EXHIBIT B

                                MFN DATA CENTERS

LA1
2260 East El Segundo Boulevard
El Segundo, CA  90245                            VA2
                                                 1807 Michael Faraday Court
NY1                                              Reston, VA  20190
111 8th Avenue, #209
New York, NY  10011                              VA 4
                                                 2051 Chain Bridge Road
NY2                                              Vienna, VA 22182
111 8th Avenue 6th Floor
New York, NY  10011

SEA2
3433 South 120th Place
Tukwila, WA  98168

SF1
365 Main Street
San Francisco, CA  94105

SJ1
50 W. San Fernando Street, 18th Floor
San Jose, CA  95113

SJ2
150 South First Street, #289
San Jose, CA  95113

SJ3
1735 Lundy Avenue
San Jose, CA   95131

VA1
8100 Boone Boulevard, Suite 110
Vienna, VA  22182

Exhibit B - Page 1

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                                    EXHIBIT C

                                FORM OF AS-BUILTS

1.        Alignment Sheets

A.        As-Built Alignment Sheets shall include the following information:

     o    Cable Information: cable type, fiber type, reel number, cable
          composition

     o    Right-of-Way: landowner/facility owner, border locations (per
          municipality)

     o    Route Information: manhole/handhole location and number,
          manhole/handhole size and ownership, splice locations, cable length
          markers at splice points and slack coils, splice enclosure type,
          attachment height (when applicable), pole number (when applicable),
          bore location (when applicable), bridge/tunnel attachment (when
          applicable), offset and depth (when applicable), location of utility
          crossings, location of reference points/permanent structures,
          transitional points, street names, conduit and innerduct position
          information/butterflies

B.        As-Built Alignment Sheets shall be updated with actual construction
          field data.

C.        The scale of As-Built Alignment Sheets shall not exceed 1" = 200' in
          metropolitan areas (areas where there is either extensive development
          and improvement or rapid growth (new building construction)) or 1" =
          500' in non-metropolitan areas.

2. Format

Drawings shall be "blue lines", as such term is understood in the industry or in
CAD format revision 14 or a later revision. MFN may, after the Acceptance Date,
adopt any replacement method of creating or providing drawings that is generally
accepted in the industry and that provides equivalent information.

3. Transmission Site Floor Plans

Floor plans for Transmission Sites shall show rack placement and assignment for
Lessee's floor space.

Exhibit C - Page 1

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                                    EXHIBIT D

                           CONSTRUCTION SPECIFICATIONS

1.0 GENERAL

The intent of this document is to outline the specifications for construction of
a fiber optic cable system. In all cases, the standards and specifications
contained in this document or the applicable standards and specifications of
federal, state, local or private agencies having jurisdiction, whichever is
stricter, shall be followed.

2.0 MATERIAL

o    Steel or PVC conduit used in any aspect of this construction effort shall
     have at least (minimum) Schedule 40 wall thickness.

o    Any exposed steel conduit, brackets or other hardware (such as bridge
     attachments) shall be hot dipped galvanized following fabrication to resist
     corrosion.

o    All split steel shall be flanged.

o    All handholds (fiber optic cable splice points) shall have a minimum
     loading rating of H20 with 24 inches of cover ( for railroads or non-street
     applications). For street applications, handholds /covers will be buried
     flush with the road surface.

o    All manholes shall have a minimum loading rating of H20.

o    All innerducts shall be one and one quarter inches (1.25") in diameter or
     the smallest diameter size possible to allow the pulling of the fiber optic
     cable as specified elsewhere in this document.

o    Buried cable warning tape ( stretch type ) shall be three (3) inches wide
     and display the following information: "Warning: Buried Fiber Optic Cable",
     Company Name and Logo, local and emergency One Call "800" telephone
     numbers. This information shall be repeated along the warning tape at
     intervals of no more than 24 inches.

o    Warning signs or stakes will display the universal " Do Not Dig" symbol. In
     addition, the warning signs or stakes shall also display the following
     information: "Warning: Buried Fiber Optic Cable", Company Name and Logo,
     local and emergency One Call "800" telephone numbers.

Exhibit D - Page 1

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3.0  MINIMUM DEPTHS OF CABLE AND CONDUITS.

The minimum cover required in the placement of fiber optic cable, conduit or
inner duct shall be 42 inches except in the following instances:

o    The minimum cover in borrow ditches adjacent to roads, highways, railroads
     and interstate highways shall be 48 inches below the cleanout line or
     existing grade, whichever is greater.

o    The minimum cover across streams, river washes and other waterways shall be
     60 inches below the cleanout line or existing grade, whichever is greater.

o    At locations where the fiber optic cable, conduit or inner duct crosses
     other sub-surface utilities or other structures, the fiber optic cable,
     conduit or inner duct shall be installed in such a way as to provide a
     minimum of 12 inches of vertical clearance between it and other sub-surface
     utilities or other structures as well as maintain the applicable minimum
     depth requirement. To maintain the minimum applicable depth requirement,
     the fiber optic cable, conduit or inner duct shall be installed under the
     existing utility or other structure. If the 12 inch vertical separation
     between the fiber optic cable and other utility or structure cannot be
     obtained, then the fiber optic cable shall be encased in steel pipe.

o    In rock, the fiber optic cable, conduit or inner duct shall be placed to
     provide a minimum of 18 inches below the surface of the solid rock, or
     provide a minimum of 42 inches of total cover, whichever requires the least
     amount of rock excavation. For cover depths of 18 inches to 24 inches,
     steel pipe is required. Cover depths of 24 inches or greater do not require
     steel pipe.

o    In the case where existing steel pipelines, ducts or conduits are to be
     utilized, the existing depth shall be considered as adequate.

4.0 BURIED CABLE WARNING TAPE.

o    All fiber optic cable, conduit and inner duct shall be installed with
     buried cable (stretch Type) warning tape except where existing steel
     pipelines, conduits or other salvaged conduit systems are used. The warning
     tape as specified earlier in this document shall be placed as follows. One
     layer of warning tape shall be placed directly on top of the fiber optic
     cable, conduit or inner duct. A second layer of warning tape shall be
     placed at a depth of 12 inches below grade.

5.0 CONDUIT/INNER DUCT CONSTRUCTION.

o    All conduits or inner ducts may be placed and installed by means of
     trenching, plowing, jack and bore, mini-directional bore or directional
     bore. All conduits or inner ducts will generally be placed on level grade,
     parallel to the surface and with only gradual changes in grade elevation.

Exhibit D - Page 2

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o    Steel conduit will be joined with threaded collars, Zap-Lok or through
     welding. (Welding is the preferred joining method)

o    All paved city, state, federal and interstate highway and railroad
     crossings will be encased in HDPE or steel conduit. If the crossings are at
     grade, steel conduit is not required if the cable or inner duct is placed
     with a minimum of 10 feet of cover.

o    All longitudinal cable runs under paved streets shall be placed in steel,
     HDPE or PVC conduit.

o    Metro areas shall be defined for the purpose of this document as follows:

          a)   There are more than three (3) paved public road crossings per
               mile.

          b)   There are more than six (6) utility crossings per mile.

          c)   Developed and/or improved areas.

          d)   High growth areas.

          Note: Railroad right-of-ways are not considered metro areas.

o    All fiber optic cable crossings of major streams, rivers, bays and
     navigable waterways shall be placed in HDPE, PVC or steel conduit.

o    At all other utility or other underground obstacle crossings, the fiber
     optic cable shall be placed in split or solid steel conduit and the conduit
     will extend at least ten (10) feet beyond the edges of the obstacle in both
     directions.

o    All jack and bores will utilize steel conduit.

o    All directional and mini-directional bores will utilize HDPE or steel
     conduit.

o    Fiber optic cable placed in rock will be installed in HDPE, PVC or steel
     conduit.

o    Fiber optic cable placed in swampy or wetland areas will be installed in
     HDPE, PVC or steel conduit.

o    Fiber optic cable placed on bridges shall be installed in steel conduit and
     the conduit shall have expansion joints placed at each structural (bridge)
     expansion joint or at the minimum every 150 feet, whichever is the shorter
     distance.

o    Whenever steel, HDPE or PVC conduit is installed, it must have inner ducts
     placed inside of it. No fiber optic cable shall be run directly in a solid
     conduit. The fiber optic cable must be installed inside one of the inner
     ducts within the solid conduit.

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6.0 FIBER OPTIC CABLE INSTALLATION.

o    The fiber optic cable shall be installed by using a powered pulling winch
     and hydraulic powered assist wheels. The maximum pulling force applied to
     the fiber optic cable shall not exceed six hundred (600) pounds or as
     specified by the cable manufacturer. Sufficient pulling assists must be
     available and used to ensure that the maximum pulling force is never
     exceeded at any point along the pull. In addition, the following shall also
     be applied:

          a)   The cable shall be lubricated during all pulls.

          b)   A pulling swivel break away rated at 600 pounds of force (or as
               specified by cable manufacturer shall be used at all times.

          c)   All fiber optic splices shall be made in handholds or manholes.

          d)   A minimum of 20 meters of fiber optic cable slack shall be left
               at all intermediate handholds or manholes where no cable splicing
               takes place.

          e)   A minimum of 30 meters of fiber optic cable slack is to be left
               at all handhold and manhole cable splice locations.

          f)   A minimum of 50 meters of fiber optic cable slack is to be left
               in all facility locations such as POP sites, regenerator
               locations, amplifier locations or terminal locations.

          g)   All contractors that handle the cable will be required to attend
               manufacturer sponsored training classes.

7.0 MANHOLES AND HANDHOLDS.

o    Manholes shall be placed in traveled surface streets and shall have locking
     lids.

o    Handholds shall be placed in all other areas and they shall be installed
     with 24 inches of soil covering the handhold lid. All handholds locations
     shall be identified with cable markers on either side of the handhold with
     exact and specific information as to the location of the handhold.

o    All handhold and manhole locations shall be clearly marked on all
     installation as-build drawings.

o    Carrots (location toning devices) will be installed on all buried
     Manholes or Handholds. Carrots will be supplied by the Owner.

8.0 CABLE MARKERS (WARNING SIGNS).

o    Cable markers shall be installed at all locations where changes in cable
     running line direction occur, at all fiber optic cable manhole/handhold
     splice points, pullboxes and assist points as well as at both sides of
     street, road, highway or railroad crossing. Under no circumstances, shall
     any markers be spaced more than 500 feet apart in metro areas and more than
     1000 feet apart in non-metro areas. Markers shall always be positioned in
     such a way so that they can be seen from the route of the cable and they
     should be installed, generally, in the direction perpendicular to the cable
     route line.

Exhibit D - Page 4

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o    All handholds, manholes, splice points, assists shall be indicated on the
     marker posts. The fiber optic cable metallic member shall be grounded at
     all fiber optic cable splice point locations. A tone system will be
     utilized for cable locates, with locate terminals placed at each fiber
     optic splice point location. The locate dial up units will be placed at
     every equipment shelter along the fiber optic cable route. The locating
     tone will be carried by the metallic sheath which is part of the fiber
     optic cable assembly.

9.0 SAFETY AND ENVIRONMENTAL CONSIDERATIONS.

o    All work described in this document shall be performed in strict accordance
     with all applicable federal, state, local and private rules, laws and
     regulations relating to safety and environmental issues, including those
     set forth by OSHA and the EPA.

10.0 CABLE SPLICING AND TESTING IN THE FIELD. ( SEE DETAILED SPLICING AND
     TESTING REQUIREMENTS -EXHIBIT A )

o    The fiber optic cables entering a splice case within a splice manhole or
     handhold shall be on the same side of the case. No so called "in-line"
     splices shall be allowed.

o    Only splices from one buffer tube shall be housed in any splice tray. Under
     no circumstances will a fiber optic cable buffer tube be split between two
     or more splice trays.

o    Under no circumstances will jumpers be allowed from tray to tray.

o    All fiber splices shall be matched up color-to-color in both the buffer
     tubes and individual fiber strand cladding. Under no circumstances will
     "frogging" of fiber strands be permitted.

o    All splices shall be made with a profile alignment fusion splicing machine.
     All splices shall protected by heat shrink tubing.

o    Fiber Optic Cable Splicing, Testing and Acceptance Procedures are outlined
     in a separate attachment to this document. (Exhibit A) - -

11.0 TERMINATION OF FIBER OPTIC CABLE.

o    All fiber optic strands within the MFNS fiber optic cable will be
     terminated on MFNS provided and designated bulkheads or fiber distribution
     panels located at all MFNS regenerator, amplifier, terminal, junction and
     POP locations along the MFNS fiber route.

Exhibit D - Page 5

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NOTES:

This document outlines MFN construction specifications. These specifications are
not applicable to the entire MFN network. However, all segments have been
constructed to generally acceptable industry best practices.

Exhibit D - Page 6

<PAGE>

EXECUTION COPY

CONFIDENTIAL PORTION MARKED [*************] HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT AND FILED SEPARATELY WITH THE SECURITIES
AND EXCHANGE COMMISSION.

                      FIRST AMENDMENT TO LEASE AGREEMENT #2

         THIS FIRST AMENDMENT (this "Amendment") is made by and between
METROMEDIA FIBER NETWORK SERVICES, INC., a Delaware corporation ("MFN") and
WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability company ("Lessee").

                                   Background

Lessee and MFN are parties to that certain Lease Agreement #2 dated April 26,
2002 (the "Agreement #2").

On May 20, 2002, MFN and most of its direct and indirect domestic subsidiaries
each filed voluntary petitions for reorganization pursuant to Chapter 11 of
title 11 of the United States Code (the "Bankruptcy Code") with the United
States Bankruptcy Court for the Southern District of New York (the "Bankruptcy
Court") and MFN is currently operating its business and managing its property as
a debtor-in-possession (the "Pending Bankruptcy Case").

The parties now wish to amend the Agreement #2 in accordance with the terms set
forth in this Amendment.

NOW THEREFORE, for mutual consideration, the value of which the parties
acknowledge, the terms of the Agreement #2 are amended as follows:

1. Capitalized terms not otherwise defined in this Amendment have the meaning
ascribed in the Agreement #2.

2. The definition of "Term" is deleted and replaced with the following:

"'TERM' begins on the date of full execution of the First Amendment to this
Agreement #2 and includes the initial term and any subsequent renewal terms."

3. Section 3.2 is hereby amended to substitute "54,324 fiber miles" for 42,024
fiber miles in the first sentence.

4. The following Section 3.6 is added to the Agreement #2:

"TERM. The initial term of the agreement expires [*********] years after the
Effective Date of the First Amendment to this Agreement #2, with
[***************] renewal periods. Unless Lessee provides a minimum of 60 days
notice of termination prior to the expiration of the then-current term, the
Agreement #2 automatically renews under the same terms and conditions."

5. Section 4.1 is deleted and replaced with the following:

"Lessee shall make monthly payments to MFN in advance during the Term. Pricing
for new orders, unless otherwise agreed, will be calculated as [******] per
fiber mile per month based on the fiber miles set forth in each Product Order,
provided, however, if Lessee Fiber is designated

CONFIDENTIAL
PAGE 1 OF 4

<PAGE>
EXECUTION COPY

in the Product Order as "Unrestricted Fiber" then the pricing for such
unrestricted fiber will be [****] per fiber mile per month ("Lease Payments").
For purposes of the Agreement #2, "Unrestricted Fiber" refers to Lessee Fiber
which may be subleased as dark fiber. Notwithstanding the forging, all Product
Orders are subject to minimum pricing of [******] per month for the first 4
fibers and [******] per month for each additional fiber pair thereafter and
Lessee may not lease more than [***] of its total Lessee Fibers as Unrestricted
Fiber. The right to lease unrestricted fiber automatically terminates upon a
change of control of Lessee; provided, however, that a change of control
resulting from the recapitalization of Lessee's parent company, Williams
Communications Group, Inc. as part of its current Chapter 11 proceedings will
not cause a termination of Lessee's sublease rights so long as Lessee is not
thereafter controlled by a third-party telecommunications provider. MFN
represents that the fiber miles stated in each Product Order, are either the
actual fiber miles (calculated as the route miles traversed by the Lessee Fiber
multiplied by the number of Lessee Fiber on the route) or a bona fide estimate
thereof, such estimate calculated utilizing OTDR distances less ten percent
(10%)."

6. Section 20.3 is deleted and replaced with the following:

"RESTRICTION OF TRANSFER OF DARK FIBER RIGHTS. MFN is providing the Lessee Fiber
for Lessee's exclusive use. Except to the extent Lessee pays for the right to
sublease the Lessee Fiber as contemplated in Section 4.1, Lessee may not
sublease, swap, assign, license, sublicense, sell or share the Lessee Fiber as
"dark fiber," as such term is commonly understood in the telecommunications
industry.

7. The following Section 17.7 is added to the Agreement #2:

"CROSS DEFAULT. MFN and Lessee are parties to a Lease Agreement dated April 26,
2002 pursuant to which MFN is the lessee (the "Longhaul Agreement"). The parties
agree that a default under the Longhaul Agreement is deemed a default under this
Agreement #2, giving the non-defaulting party the right to terminate if the
Longhaul Agreement is likewise terminated. The right to terminate under this
Section 17.7 automatically expires if the non-defaulting party does not provide
notice, within 60 days of termination of the Longhaul Agreement, of its intent
to exercise its right to terminate this Agreement #2. Such termination shall be
effective 120 days after such notice, if given.

7. EFFECTIVE DATE. This Amendment is effective upon the date of the last
signature hereto ("Effective Date"). Notwithstanding the foregoing, the parties
acknowledge that the Amendment must be approved by the Bankruptcy Court pursuant
to an order, in form and substance acceptable to Lessee and MFN, which provides
for, among other things, the following: (i) assumption of the Agreement #2, as
amended, pursuant to section 365 of the Bankruptcy Code, and (ii) a finding that
the parties negotiated the Amendment at arm's length and in good faith. If such
approval is not obtained on or before October 17, 2002 or such later date as the
parties may agree to, this Amendment will be null and void and of no force or
effect and Lessee agrees to pay the difference between the amended amounts
invoiced for October and the actual amounts owed under the Agreement #2.

8. ASSUMPTION AND WAIVER OF SPECIFIC CLAIMS. If following the assumption of the
Agreement #2:

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         (a) one or more metro fiber rings currently operated by MFN on which
Lessee has Lessee Fiber, is effectively abandoned because MFN elects no longer
to operate those markets and the markets are sold to a third party, then any
damage claim of Lessee arising from the effective abandonment of any such market
is a general unsecured claim in the Pending Bankruptcy Case; and/or

         (b) one or more, but less than all, MFN's metropolitan networks are
sold to a third party who intends to operate such networks, then, subject to
Lessee's rights under section 365 of the Bankruptcy Code as described below,
Lessee and MFN will execute a new agreement in all respects identical to the
existing Agreement #2 but which includes only the Lessee Fiber in markets sold
to a third party. The new agreement may be assigned by MFN to the third party
pursuant to section 365 of the Bankruptcy Code, and the existing Agreement #2
will be deemed amended to eliminate the assigned Lessee Fiber from its scope.
The occurrence of events contemplated by this subparagraph is not a breach by
MFN of the Agreement #2 and will not give rise to a claim. Lessee may object to
any assignment pursuant to section 365 of the Bankruptcy Code on the grounds
that Lessee is not receiving adequate assurance of future performance or that an
assignment to the third party assignee in question is otherwise not permitted
under the Bankruptcy Code; provided, however, that in the event Lessee's
objection to such assignment is sustained but the relevant network is
nevertheless sold to the third party, the parties agree that damages, if any,
arising from the breach resulting from MFN's inability to provide service to
Lessee under the Agreement #2 with respect to the Lessee sold to the third
party, will be a general unsecured claim in the Pending Bankruptcy Case; or

         (c) the Agreement #2 is terminated due to MFN's failure to perform or
its rejection thereof, nothing herein constitutes a waiver of Lessee's right to
a general unsecured claim for all outstanding Pre-Petition Debt and an
administrative claim for post petition damages caused by any breach of the
Agreement #2, or of the right of MFN or any party in interest to object to any
such claim. Any and all administrative expense claims will require Williams
Communications to satisfy the requirements of the Bankruptcy Code to establish
the claim and is without prejudice to any other party's right to contest such
claim; and/or

9. Except as amended, all of the original terms and conditions of the Agreement
#2 continue in full force and effect, neither party is in currently in default,
and the Agreement #2, as amended is hereby ratified and confirmed.

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10. This Amendment may be executed in counterparts, each of which taken together
constitute one and the same instrument.

The parties have executed this Amendment on the dates set forth below.

METROMEDIA FIBER NETWORK SERVICES, INC., a Delaware corporation

Signature:        /s/ William G. La Perch
          ----------------------------------------------------

(Print) Name:     William G. La Perch
              ------------------------------------------------

(Print) Title:    Sr. Vice President
              ------------------------------------------------

(Print) Date:     10/10/02
             -------------------------------------------------

WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability company

Signature:        /s/ Frank M. Semple
          ----------------------------------------------------

(Print) Name:      Frank M. Semple
              ------------------------------------------------

(Print) Title:    Chief Operating Officer
              ------------------------------------------------

(Print) Date:     10/2/02
             -------------------------------------------------

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