<PAGE>   1

                                                                 EXHIBIT 10.18.2

IXC                          AMENDMENT NO. 2 TO IXC
COMMUNICATIONS, INC.        MASTER SERVICE AGREEMENT

This Amendment No. 2 to the Master Service Agreement is made and entered into by
and between IXC COMMUNICATIONS SERVICES, INC., f/k/a IXC Carrier, Inc./IXC Long
Distance, Inc./IXC Broadband Services, Inc. (generically "IXC"), a Delaware
corporation with its principal place of business at 1122 Capital of Texas Hwy.
South, Austin, Texas 78746 ("Supplier"), and UNIVERSAL ACCESS, INC., an Illinois
corporation with its principal place of business at 100 North Riverside Plaza,
Suite 2200, Chicago, Illinois 60606-1502 ("Customer").

For purposes of this Amendment, the rates, terms and conditions set forth herein
shall become effective on the first day of the next IXC billing cycle following
the last date of execution below (the "Amendment Effective Date").

This Amendment is made with reference to the following facts:

        A.      Customer and Supplier are parties to that certain Master Service
Agreement dated as of November 6, 1997 and subsequent Amendment No. 1 dated
March 23, 1999 (as amended, the "Agreement").

        B.      The parties desire to amend the Agreement pursuant to the terms
set forth below.

                               TERMS OF AMENDMENT

Accordingly, in consideration of the mutual promises set forth below, the
parties agree as follows:

        1.      Section 8, Notices, of the Master Service Agreement Terms &
Conditions shall be modified as follows:

        8.      NOTICES. All notices and other communications hereunder shall be
                in writing and shall be deemed to have been duly given as of the
                date of delivery, facsimile transmission or mailing, and if
                mailed, first class postage prepaid, certified or registered
                mail, return receipt requested to the following persons, unless
                contrary instructions are given by the parties in writing:

                If to Supplier: IXC Communications Services, Inc.
                                1122 Capital of Texas Hwy. South
                                Austin, Texas 78746-6426
                                Attention: Contract Administration

               If to Customer:  Universal Access, Inc.
                                100 North Riverside Plaza, Suite 2200
                                Chicago, Illinois 60606-1502
                                Attention: Robert J. Pommer, COO

        2.      Exhibit D, Private Line Pricing, shall be replaced in its
entirety by Exhibit D, Private Line Pricing, attached hereto.

        3.      All other terms and conditions, provisions, supplements and
exhibits of the Agreement shall remain in full force and effect.



                         [SIGNATURE LINES ON NEXT PAGE]

<PAGE>   2

IN WITNESS WHEREOF, the parties have executed this Amendment as of the date last
written below.

IXC COMMUNICATIONS SERVICES, INC.       UNIVERSAL ACCESS, INC.


BY: /s/ LEO WEISH                       BY: /s/ ROBERT J. POMMER
   ---------------------------------       -------------------------------------

NAME: LEO WEISH                         NAME: Robert J. Pommer
     -------------------------------         -----------------------------------

TITLE: PRES-WHOLESALE                   TITLE: Chief Operating Officer
      ------------------------------          ----------------------------------

DATE: 7/19/99                           DATE: 7/1/99
     -------------------------------         -----------------------------------

<TABLE>
<S>                                                       <C>
FULL BUSINESS ADDRESS:                                    FULL BUSINESS ADDRESS:
1122 CAPITAL OF TEXAS HWY. SOUTH                          100 NORTH RIVERSIDE PLAZA, SUITE 2200
AUSTIN, TEXAS 78746-6426         Approved as to form      CHICAGO, ILLINOIS 60606-1502
TELEPHONE: (512) 427-3700            Legal dept.          TELEPHONE: (312) 660-5000
FACSIMILE: (512) 328-7902                                 FACSIMILE: (312) 660-5050
                                                          BILLING CONTACT: ACCOUNTS PAYABLE
                                                          TELEPHONE: (312) 660-5000
</TABLE>



                             AMENDMENT NO. 2 TO MSA

<PAGE>   3




EXHIBIT D - PRIVATE LINE PRICING
--------------------------------

<TABLE>
<CAPTION>
                                           RATE PER   V&H DS-0  MILE/CIRCUIT  LEASE TERM
SERVICE TYPE      MONTHLY VOLUME            1 YEAR    2 YEARS      3 YEARS      4 YEARS    5 YEARS
------------      --------------           --------   --------  ------------  ----------   -------
<S>               <C>                      <C>        <C>       <C>           <C>          <C>
DS-0              N/A                       [***]     [***]     [***]         [***]        [***]

DS-1              [***]                     [***]     [***]     [***]         [***]        [***]
                  [***]

DS-3              [***]                     [***]     [***]     [***]         [***]        [***]
                  [***]

OC-3              [***]                     [***]     [***]     [***]         [***]        [***]
                  [***]

OC-12             [***]                     [***]     [***]     [***]         [***]        [***]
                  [***]

OC-48             [***]                     [***]     [***]     [***]         [***]        [***]


MINIMUM CIRCUIT CHARGES:

                             DS-0                  [***]
                             DS-1                  [***]
                             DS-3                  [***]
                             OC-3                  [***]
                             OC-12                 [***]
                             OC-48                 [***]

MINIMUM CIRCUIT TERM:        1 Year
</TABLE>

NOTES:

1.      ALL PRIVATE LINE SERVICE TO CITIES NOT LISTED ON EXHIBIT C WILL BE
        PRICED ON AN INDIVIDUAL CASE BASIS AND WILL BE SUBJECT TO THE TERMS OF
        THE UNDERLYING CARRIER.

2.      EXISTING CIRCUITS MAY BE RE-RATED AT THE [***] MONTHLY VOLUME RATES
        PROVIDED (A) CUSTOMER REACHES AND MAINTAINS [***] IN INVOICED MONTHLY
        VOLUME AND (B) CUSTOMER SUBMITS A NEW MARKET SERVICE ORDER FOR EACH
        CIRCUIT TO BE RE-RATED WITH A NEW CIRCUIT LEASE TERM.



          AMENDMENT NO. 2 TO MSA PRIVATE LINE SERVICES EXHIBIT - PAGE 7


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