UNITED USN, INC.

                                 $137,000,000

                      14% SENIOR DISCOUNT NOTES DUE 2003


                        -------------------------------
                         FIRST SUPPLEMENTAL INDENTURE

                          Dated as of March 17, 1997
                        -------------------------------


                        HARRIS TRUST AND SAVINGS BANK,

                                    Trustee




                    FIRST SUPPLEMENTAL INDENTURE, dated as of March
          17, 1997, between UNITED USN, INC., a Delaware
          Corporation (the "Company"), having its principal office
          at 10 South Riverside Plaza, Suite 401, Chicago, Illinois
          60606-3709, and HARRIS TRUST AND SAVINGS BANK, as trustee
          hereunder (the "Trustee"), having its Corporate Trust
          Office at 311 West Monroe, Chicago, Illinois 60606.

                                   RECITALS

                    The Company has heretofore executed and
          delivered to the Trustee an Indenture for its 14% Senior
          Discount Notes due 2003 (the "Senior Notes"), dated as of
          September 30, 1996 (the "Indenture"), providing for the
          issuance of the Senior Notes.

                    Section 9.01 of the Indenture provides that the
          Company and the Trustee may, at any time, without notice
          to or consent of any Holders of Senior Notes, enter into
          an indenture supplemental to the Indenture for the
          purpose of curing any ambiguity in the Indenture, or
          correcting any provision of the Indenture, provided that
          such action shall not adversely affect the interests of
          the Holders of Senior Notes in any material respect.

                    NOW, THEREFORE, THIS FIRST SUPPLEMENTAL
          INDENTURE WITNESSETH:

                    For and in consideration of the premises, it is
          mutually agreed, for the equal and proportionate benefit
          of all Holders of the Senior Notes, as follows:

                                  ARTICLE I

                      Relation to Indenture; Definitions

                    Section 1.1  This First Supplemental Indenture
          constitutes an integral part of the Indenture.

                    Section 1.2  Capitalized terms used herein
          without definition shall have the meanings specified in
          the Indenture.


                                  ARTICLE II

                               Outside Director

                    Section 2.1  The covenant set forth in Section
          4.22 of the Indenture shall be deleted and replaced with
          the following:

                    SECTION 4.22.  Outside Director.  The Company
          shall, within 120 days following the Closing Date,
          nominate and take all reasonable actions to cause to be
          elected a disinterested outside Director to the Board of
          Directors of the Company who is not a Director on the
          Issue Date and who has experience in the
          telecommunications industry (an "Additional Outside
          Director").  At all times during the period commencing
          120 days following the Closing Date and ending on
          Maturity, in the event that an Additional Outside
          Director (or any successor Additional Outside Director)
          is no longer serving as a Director, the Company shall, as
          promptly as practicable, nominate and take all reasonable
          actions to cause to be elected, a successor Additional
          Outside Director.


                    IN WITNESS WHEREOF, the parties hereto have
          caused this First Supplemental Indenture to be duly
          executed, and their respective corporate seals to be
          hereunto affixed and attested, on the date or dates
          indicated in the acknowledgements and as of the day and
          year first above written.

                                        UNITED USN, INC.

                                        By /s/ J. Thomas Elliott
                                           _________________________
                                        Name:   J. Thomas Elliott
                                        Title:  President and Chief
                                                Executive Officer

          [Corporate Seal]

          Attest:

          /s/ Thomas A. Monson
          ------------------------


                                        HARRIS TRUST AND SAVINGS
                                        BANK,
                                             as Trustee

                                        By /s/ J. Bartolini
                                           ________________________
                                        Name:   J. Bartolini
                                        Title:  Vice President

          [Corporate Seal]

          Attest:

          _______________________



          STATE OF ILLINOIS             )
                                        )    SS.:
          COUNTY OF COOK           )

               On the 17th day of March, 1997, before me personally
          came J. Thomas Elliott, to me known, who being by me duly
          sworn, did depose and say that he is President and Chief
          Executive Officer of United USN, Inc., one of the
          corporations described in and which executed the
          foregoing instrument; that he knows the seal of said
          corporation; that the seal affixed to said instrument is
          such corporate seal; that it was so affixed by authority
          of the Board of Directors of said corporation, and that
          he signed his name thereto by like authority.


                                   /s/ Lisa Ann Solava
                                   _______________________________
                                   Notary Public

                                   State of Illinois
                                   My commission expires

          [Corporate Seal]



          STATE OF ILLINOIS        )
                                   )    SS.:
          COUNTY OF COOK           )

               On the 18 day of March, 1997, before me personally
          came J. Bartolini, to me known, who being by me
          duly sworn, did depose and say that he is Vice President
          of Harris Trust and Savings Bank, the Trustee described
          in and which executed the foregoing instrument; that he
          knows the seal of said corporation; that the seal affixed
          to said instrument is such corporate seal; that it was so
          affixed by authority of the Board of Directors of said
          corporation, and that he signed his name thereto by like
          authority.

                                   /s/ Marianne Cody
                                   _______________________________
                                   Notary Public

                                   State of Illinois
                                   My commission expires

          [Corporate Seal]