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                                                        Exhibit 10.27.2


                       LEASE MODIFICATION AGREEMENT # 1

     This Lease Modification Agreement # 1  ("Agreement") dated this 30th day of
September, 1998, is by and between 290 Woodcliff Drive Company, a general
partnership organized and existing pursuant to the laws of the State of New York
with a principal office at c/o The Widewaters Group, Inc., P.O. Box 3, 5786
Widewaters Parkway, Dewitt, New York 13214-0003 ("Landlord"), and PaeTec
Communications, Inc., a corporation with a principal office at 290 Woodcliff
Drive, Fairport, New York 14450 ("Tenant").

                                WITNESSETH THAT:

     WHEREAS, Landlord and Tenant entered into a Standard Office Space Lease
dated as of July 10, 1998 ("Lease") relating to office space in the Woodcliff
III Office Building, located at  290 Woodcliff Drive, Fairport, New York;

     WHEREAS, the Lease shall expire on December 31, 1999;

     WHEREAS, pursuant to the provisions of Section 22.27 of the Lease, Tenant
has agreed to expand the Premises by accepting an additional 8,055 leasable
square feet from Landlord, as shown on Exhibit A-1, attached hereto and made a
part hereof;

     WHEREAS, as of the date of this Agreement, Landlord has not delivered the
8,055 leasable square feet of premises to Tenant;

  WHEREAS, Tenant desires to further expand the Premises to include an
additional 2,678 leasable square feet shown on Exhibit A-1 attached hereto and
made a part hereof;

  WHEREAS, Landlord has agreed to deliver, and Tenant has agreed to accept the
additional 2,678 leasable square feet upon the terms and conditions of this
Agreement;

     WHEREAS, as part of such expansion of the Premises, Landlord and Tenant
agree to modify and amend the Lease in order to reflect the same and to reflect
certain other modifications as set forth herein.

  NOW THEREFORE, in consideration of the foregoing and other good and valuable
consideration, the receipt and legal sufficiency of which is hereby
acknowledged, Landlord and Tenant hereby agree as follows:

1.   Capitalized terms not defined in this Agreement shall have the meaning
ascribed to them in the Lease.

2.   The Lease is hereby modified as follows:

a.   Section 1.01 is hereby modified by deleting the sentence beginning with
     "For purposes of this Section 1.01..." and ending with "...from and after
     the Delivery Date."  and inserting the following in its place and stead:

          "For purposes of this Section 1.01, the sum of the square feet in the
          Premises and Tenant's share of Building Common Areas (as defined in
          Section 1.02 hereof) shall be 8,397 leasable square feet as of the
          Term Commencement Date.  Upon the Delivery Date of the Expansion
          Premises (as both terms are defined in Section 22.27 below) the number
          of leasable square feet contained in the Premises shall automatically
          be increased by 8,055 leasable square feet.  And upon the Turn Over
          Date of the Additional Premises (as both terms are defined in Section
          22.28 below) the number of leasable square feet contained in the
          Premises shall automatically be increased by 2,678 leasable square
          feet. Upon the later of (i) the Delivery Date, or (ii) the Turn Over
          Date, Tenant's Premises shall consist of a total of 19,130 leasable
          square feet."

b.   Section 3.01 is hereby modified by replacing the first paragraph of the
     Section with the following:

          "Tenant agrees to pay to Landlord at the offices of Landlord, or at
          such other place designated by Landlord, without any prior demand
          therefor and without any deduction or set-off whatsoever, and as fixed
          monthly rent, the sum of Twelve Thousand Seven Hundred Eighty-eight
          and 96/100 Dollars ($12.788.96) (sometimes referred to herein as
          "Fixed Monthly Rent"), payable in advance upon the first day of each
          calendar month during the term hereof. The monthly installment shall
          be deemed to have been paid upon such first day only if actually
          received by such first day. Anything contained in the foregoing to the
          contrary notwithstanding, the amount of Fixed Monthly Rent payable to
          Landlord is subject to automatic increases in accordance with Sections
          22.27 and 22.28 of this Lease."

c.   Section 22.27 of the Lease is hereby modified by the addition of the
     following to the end of the first paragraph of said Section:

          "Upon the Delivery Date, Tenant's Fixed Monthly Rent then in effect
          shall automatically increase by Thirteen Thousand Eighty-nine and
          38/100 Dollars ($13,089.38) and shall be due in accordance with and be
          subject to the provisions of Section 3.01."

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d.   Section 22.28 is hereby added to the Lease and shall state as follows:

     "22.28 Additional Premises

                Landlord agrees to deliver approximately 2,678 leasable square
          feet of additional premises located on the first floor of the Building
          ("Additional Premises") to Tenant and Tenant agrees to accept
          possession of the Additional Premises in its "as is" condition. The
          date that Landlord notifies Tenant that possession of the Additional
          Premises is available to Tenant is hereinafter referred to as the
          "Turn Over Date". As of the Turn Over Date, the term "Premises", as
          defined in Section 1.01 above, and as use throughout this Lease, shall
          automatically be deemed to mean and include the Additional Premises
          and Tenant's Fixed Monthly Rent then in effect shall automatically
          increase by Four Thousand Three Hundred Fifty-one and 75/100 Dollars
          ($4,351.75) and shall be due in accordance with and be subject to the
          provisions of Section 3.01."

e.   Exhibit "A" to the Lease is hereby replaced by Exhibit "A-1", attached
     hereto and made a part hereof, and all references to Exhibit "A" in the
     Lease shall be deemed to refer to Exhibit "A-1.

3.   Tenant agrees to pay to Landlord additional security in the amount of
Four Thousand Three Hundred Fifty-one and 75/100 Dollars ($4,351.75) upon its
execution and delivery of this Agreement.  Such amount shall be held by Landlord
in accordance with and shall be subject to the provisions of Section 3.05 of the
Lease.

4.   This Agreement may be executed in one or more counterparts, any one or
all of which constitute one document.

5.   Tenant hereby certifies to Landlord that as of the date hereof: (i) the
Lease is in full force and effect; (ii) there currently exist no default by
Landlord under the Lease, nor any condition which with the giving of notice or
the passage of time, or both, would constitute a default under the Lease on the
part of Landlord; (iii) Tenant has no existing set-offs, counterclaims or
defenses against Landlord under the Lease; and (iv) the Lease as modified hereby
contains the entire agreement between the parties hereto with respect to the
Premises, the Lease and the Building.

6.   Tenant represents and warrants that it has taken all necessary
corporate, partnership or other action necessary to execute and deliver this
Agreement, and that this Agreement constitutes the legally binding obligation of
Tenant enforceable in accordance with its terms.  Tenant further represents and
warrants that it has full and complete authority to enter into and execute this
Agreement and acknowledges that Landlord is relying upon Tenant's representation
of its authority to execute this Agreement and Tenant shall save and hold
Landlord harmless from any claims, or damages including reasonable attorneys'
fees arising from Tenant's misrepresentation of its authority to enter into and
execute this Agreement.

7.   The effective date of this Agreement for all purposes shall be upon its
full execution and it shall not be binding unless and until executed on behalf
of both parties hereof.

8.   As of the effective date, this Agreement shall be attached to and
automatically be deemed a part of the Lease.  Except as herein modified and
amended, all other terms and conditions of the Lease are hereby ratified and
shall continue in full force and effect.

IN WITNESS WHEREOF, Landlord and Tenant have executed this Lease Modification
Agreement # 1.

                                       LANDLORD:
                                       290 Woodcliff Drive Company


                                       By: /s/ Joseph R. Scuderi
                                           ----------------------------------
                                       Joseph R. Scuderi
                                       Member of the Executive Committee


                                       TENANT:
                                       PaeTec Communications, Inc.


                                       By: /s/ Arunas A. Chesonis
                                           ----------------------------------
                                       Arunas A. Chesonis, President and CEO


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STATE OF NEW YORK     )
                      SS.:
COUNTY OF ONONDAGA    )

On this 30th day of September, 1998, before me personally came Joseph R.
Scuderi, to me personally known, who, being by me duly sworn, did depose and say
that he resides in Manluis, N.Y.; that he is a Member of the Executive Committee
of 290 Woodcliff Drive Company; that he is known to me to be one of the Members
of the Executive Committee of the partnership that executed the within
instrument; and he acknowledged to me that he executed the same on behalf of and
in the name of such partnership.

                                                /s/ Margo M. McCaffery
                                                -------------------------------
                                                NOTARY PUBLIC
                                                MARGO M. McCAFFERY
                                                Notary Public, State of New York
                                                        No. 01MC5056553
                                                Qualified in Madison County
                                                Commission Expires March 4, 2000


STATE OF NEW YORK     )
                      SS.:
COUNTY OF MONROE      )

On this 28th day of September, 1998, before me personally came Arunas A.
Chesonis, to me personally known, who, being by me duly sworn, did depose and
say that he resides in Rochester, NY, that he is the President and CEO of
PaeTec Communications, Inc. the corporation described in and which executed the
within instrument; and that he signed his name thereto by order of the Board of
Directors of said corporation.

                                          /s/ Marcia A. Benwitz
                                          -------------------------------
                                          NOTARY PUBLIC
                                          MARCIA A. BENWITZ
                                          Notary Public, State of New York
                                                  Monroe County
                                          My Commissioin Expires Sept. 30, 1998


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