FIRST AMENDMENT
                                       TO
                                RIGHTS AGREEMENT


         This FIRST AMENDMENT TO RIGHTS  AGREEMENT  ("Amendment") is dated as of
March 4, 1999,  and is entered  into by and between  Data  Transmission  Network
Corporation,  a Delaware  corporation  ("DTN"), and First National Bank of Omaha
("Rights Agent").

                                    RECITALS:

         A. DTN and Rights Agent are all of the present  parties to that certain
Rights  Agreement  dated as of August 29,  1997 (the  "Agreement").  Capitalized
terms not  defined  in this  Amendment  shall  have the  meanings  given to such
defined terms in the Agreement.

         B. In accordance  with the  provisions of Section 27 of the  Agreement,
the members of the Board of  Directors of DTN (which also  presently  constitute
the Continuing  Directors) have  unanimously  approved this  Amendment,  and the
Secretary of DTN has delivered to the Rights Agent a certificate  to such effect
and has directed  the Rights Agent to execute this  Amendment as provided in the
Agreement.

         NOW, THEREFORE, in consideration of the mutual covenants and agreements
set forth therein and herein, the parties hereto agree as follows:

         1. Amendments to Agreement. (a) Effective immediately,  Section 1(a) of
the  Agreement  is amended by  deleting it in its  entirety  and  inserting  the
following in its place:

               "(a)  "Acquiring  Person"  shall mean any Person (as such term is
         hereinafter  defined)  who or which shall be the  Beneficial  Owner (as
         such  term is  hereinafter  defined)  of 15% or more of the  shares  of
         Common Stock then  outstanding,  but shall not include an Exempt Person
         (as such term is hereinafter defined);  provided,  however, that (i) if
         the Board of Directors of the Company  determines  in good faith that a
         Person  who  would  otherwise  be an  "Acquiring  Person"  became  such
         inadvertently (including,  without limitation,  because (A) such Person
         was unaware that it  beneficially  owned a  percentage  of Common Stock
         that would otherwise  cause such Person to be an "Acquiring  Person" or
         (B) such Person was aware of the extent of its Beneficial  Ownership of
         Common Stock but had no actual  knowledge of the  consequences  of such
         Beneficial Ownership under this Agreement) and without any intention of
         changing or influencing  control of the Company,  and if such Person as
         promptly  as  practicable  divested  or  divests  itself of  Beneficial
         Ownership of a sufficient number of shares of Common Stock so that such
         Person would no longer be an "Acquiring Person," then such Person shall
         not be deemed to be or to have  become an  "Acquiring  Person"  for any
         purposes  of  this  Agreement;  and  (ii) no  Person  shall  become  an
         "Acquiring  Person" as the result of an acquisition of shares of Common
         Stock  by  the  Company  which,   by  reducing  the  number  of  shares
         outstanding,  increases  the  proportionate  number of shares of Common
         Stock beneficially owned by such Person to 15% or more of the shares of

                                       
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         Common  Stock then  outstanding,  provided,  however,  that if a Person
         shall  become  the  Beneficial  Owner of 15% or more of the  shares  of
         Common Stock then  outstanding by reason of such share  acquisitions by
         the Company and shall  thereafter  become the  Beneficial  Owner of any
         additional shares of Common Stock (other than pursuant to a dividend or
         distribution  paid or made by the  Company  on the  outstanding  Common
         Stock in shares of Common  Stock or pursuant to a split or  subdivision
         of the outstanding  Common Stock),  then such Person shall be deemed to
         be an "Acquiring  Person" unless upon becoming the Beneficial  Owner of
         such   additional   shares  of  Common   Stock  such  Person  does  not
         beneficially  own  15% or more  of the  shares  of  Common  Stock  then
         outstanding. For all purposes of this Agreement, any calculation of the
         number of shares of Common Stock  outstanding at any  particular  time,
         including for purposes of determining the particular percentage of such
         outstanding  shares  of  Common  Stock  of  which  any  Person  is  the
         Beneficial Owner, shall be made in accordance with the last sentence of
         Rule  13d-3(d)(1)(i)  of the General  Rules and  Regulations  under the
         Securities Exchange Act of 1934, as amended (the "Exchange Act"), as in
         effect on the date hereof."

               (b)  Effective  immediately,  Section  1(q) of the  Agreement  is
         amended  by  substituting  the  figure  15% in place of the  figure 11%
         contained therein.

               (c)  Effective  immediately,  Section  3(a) of the  Agreement  is
         amended  by  substituting  the  figure  15% in place of the  figure 11%
         contained therein.

         2. Binding  Effect.  This Amendment  shall be binding upon and inure to
the  benefit  of DTN and  Rights  Agent  and  their  respective  successors  and
permitted assigns.

         3. Superseding.  From and after the date hereof,  all references to the
Agreement shall mean the Agreement, as amended by this Amendment.

         4.  Confirmation.  Except  as  otherwise  expressly  set  forth in this
Amendment,  the  Agreement is hereby  ratified and confirmed and remains in full
force and effect.

         5.  Counterparts.  This  Amendment  may be  executed  in any  number of
counterparts,  all of which taken  together  shall  constitute  one and the same
instrument  and any of the parties  hereto may execute this Amendment by signing
any such counterpart.

         IN WITNESS WHEREOF,  the parties have executed this Amendment as of the
date and year first above written.

                                   DATA  TRANSMISSION  NETWORK
                                   CORPORATION


                                   By:/s/ Greg T. Sloma
                                      -------------------------------
                                      Greg T. Sloma, President


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                                   FIRST NATIONAL BANK OF OMAHA,
                                   as Rights Agent


                                   By: /s/ John E. Lenihan
                                       ------------------------------
                                   Title: Trust Officer




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