SIXTH AMENDMENT TO 1993 RESTATED LOAN AGREEMENT


        THIS SIXTH  AMENDMENT  TO 1993  RESTATED  LOAN  AGREEMENT is intended to
amend the terms of the 1993 Restated Loan Agreement (the  "Agreement")  dated as
of  November  8, 1993,  as  amended  by the First  Amendment  to  Restated  Loan
Agreement (the "First  Amendment") dated as of April 11, 1994, as amended by the
Second  Amendment to and Extension of 1993 Restated Loan  Agreement (the "Second
Amendment") dated as of June 29, 1994, as amended by the Third Amendment to 1993
Restated Loan Agreement (the "Third  Amendment") dated as of August 30, 1994, as
amended by the Fourth  Amendment to 1993  Restated Loan  Agreement  (the "Fourth
Amendment") dated as of November 29, 1994, and as amended by the Fifth Amendment
to 1993 Restated Loan Agreement (the "Fifth Amendment") dated as of February 27,
1995, among DATA TRANSMISSION NETWORK CORPORATION, FIRST NATIONAL BANK OF OMAHA,
FIRSTIER BANK, NATIONAL  ASSOCIATION,  LINCOLN,  NEBRASKA,  FIRST NATIONAL BANK,
WAHOO, NEBRASKA,  NBD BANK, N.A., NORWEST BANK NEBRASKA,  N.A. and THE BOATMEN'S
NATIONAL BANK OF ST.  LOUIS.  All terms and  conditions  of the Agreement  shall
remain in full  force  and  effect  except  as  expressly  amended  herein.  All
capitalized  terms herein shall have the meanings  prescribed in the  Agreement.
The Agreement shall be amended as follows:

        (a)     The definition of "Consolidated Tangible Net Worth" in
        Article I of the Agreement shall be deleted.

        (b) The last sentence of Section 4.3 of the  Agreement  shall be deleted
        and all references in the Agreement to Section 4.3 shall, after the date
        hereof, exclude any reference to the omitted sentence.

        This  Amendment  may  be  executed  in  several  counterparts  and  such
counterparts together shall constitute one and the same instrument.

        IN WITNESS  WHEREOF,  the undersigned have executed this SIXTH AMENDMENT
TO 1993 RESTATED LOAN AGREEMENT dated as of April 28, 1995.

                                             DATA TRANSMISSION NETWORK
                                             CORPORATION


                                             By:    /s/  Greg T. Sloma
                                                    ----------------------------
                                             Title:  Executive Vice President
                                                     and Chief Operating Officer
                                                     ---------------------------

                                       33
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                                            FIRST NATIONAL BANK OF OMAHA

                                          By:     /S/ James P. Bonham 
                                               --------------------------
                                          Title:  Vice President
                                               --------------------------


                                            FIRSTIER BANK, NATIONAL
                                            ASSOCIATION, LINCOLN, NEBRASKA


                                          By:     /s/ John Arrigo
                                               ----------------------------
                                          Title:  Officer
                                               ----------------------------
 

                                            FIRST NATIONAL BANK, WAHOO,
                                            NEBRASKA

                                          By:     /s/  Elizabeth E. Rezac
                                               ----------------------------
                                          Title:  Loan Officer
                                               ----------------------------

                                            NBD BANK, N.A.

                                          By:   /s/ Thomas A. Levasseur
                                               ----------------------------
                                          Title:  Vice President
                                               ----------------------------


                                            NORWEST BANK NEBRASKA, N.A.

                                         By:    /s/  Leslie J. Volk
                                               ----------------------------
                                          Title:  Vice President
                                               ----------------------------


                                            THE BOATMEN'S NATIONAL BANK
                                            OF ST. LOUIS


                                         By:    /s/ Joseph L. Scooter, Jr.
                                               ----------------------------
                                          Title:   Vice President
                                               ----------------------------


4429E/70-76
                                       34
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