FIRST AMENDMENT TO 1997 REVOLVING CREDIT AGREEMENT


         THIS FIRST  AMENDMENT to 1997  REVOLVING  CREDIT  AGREEMENT (the "First
Amendment")  is  intended  to  amend  the  terms of the  1997  Revolving  Credit
Agreement  (the  "Agreement")   dated  as  of  February  26,  1997,  among  DATA
TRANSMISSION NETWORK  CORPORATION;  FIRST NATIONAL BANK OF OMAHA; FIRST NATIONAL
BANK, WAHOO, NEBRASKA; NBD BANK, N.A.; NORWEST BANK NEBRASKA, N.A.; THE SUMITOMO
BANK,  LIMITED;  MERCANTILE  BANK  OF ST.  LOUIS,  N.A.;  FIRST  BANK,  NATIONAL
ASSOCIATION; BANK OF MONTREAL; LASALLE NATIONAL BANK; 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:

         The parties hereby  acknowledge that,  effective as of the date hereof,
$38,000,000 of the outstanding balance of the Borrower's loan shall be converted
to a term loan in accordance with Section 2.4 of the Agreement.  Such loan shall
bear interest at the rate of 7.865% per annum.  In Section 2.1 of the Agreement,
the reference to the maximum amount of revolving credit available to be advanced
shall be reduced from  $59,500,000  to  $33,000,000,  and the references to each
Bank's maximum  advance limit shall be reduced  accordingly on a pro rata basis,
as shown on  Exhibit  A. No  further  increases  in the  Base  Revolving  Credit
Facility are available to be implemented under Section 2.1 of the Agreement.

         In   connection   with   this   First   Amendment   the   Borrower   is
contemporaneously executing and delivering to the Banks Converted Notes dated as
of the date  hereof  in the  respective  principal  amounts  shown on  Exhibit A
hereto.  This First Amendment shall not affect and there remain outstanding from
the Borrower to the Banks, the Existing Term Notes and the Related Bank Debt.

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

         Except as expressly  agreed  herein,  all terms of the Agreement  shall
remain in full force and effect.

         IN WITNESS WHEREOF,  the undersigned have executed this FIRST AMENDMENT
TO 1997 REVOLVING CREDIT AGREEMENT dated as of March 31, 1997.


                                       1

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<PAGE>

                                           DATA TRANSMISSION NETWORK
                                           CORPORATION



                                            By
                                              ----------------------------------
                                              Title:


                                    - 157 -
<PAGE>


                                            FIRST NATIONAL BANK OF OMAHA



                                           By
                                             -----------------------------------
                                             Title:


NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower


                                       2

                                    - 158 -
<PAGE>

                                           THE SUMITOMO BANK, LIMITED


                                           By
                                             -----------------------------------
                                             Title:



                                           By
                                             -----------------------------------
                                             Title:







NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:


                                           --------
                                           Borrower




                                       3

                                    - 159 -
<PAGE>






                                           FIRST NATIONAL BANK, WAHOO,
                                           NEBRASKA



                                           By
                                             -----------------------------------
                                             Title:




NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower


                                       4

                                   - 160 -
<PAGE>




                                           NBD BANK


                                           By
                                             -----------------------------------
                                             Title:


NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower


                                       5

                                    - 161 -
<PAGE>







                                           NORWEST BANK NEBRASKA, N.A.



                                           By
                                             -----------------------------------
                                             Title:


NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower

                                       6

                                    - 162 -
<PAGE>







                                           LASALLE NATIONAL BANK, a national
                                           banking association




                                           By
                                             -----------------------------------
                                             Title:


NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower



                                       7

                                    - 163 -
<PAGE>








                                           MERCANTILE BANK OF
                                           ST. LOUIS, N.A.


                                           By
                                             -----------------------------------
                                             Title:


NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower



                                       8

                                    - 164 -
<PAGE>







                                           FIRST BANK, NATIONAL
                                           ASSOCIATION


                                           By
                                             -----------------------------------
                                             Title:


NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower

                                       9

                                    - 165 -
<PAGE>






                                           THE BOATMEN'S NATIONAL BANK
                                           OF ST. LOUIS



                                           By
                                             -----------------------------------
                                             Title:


NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower



                                       10

                                    - 166 -
<PAGE>






                                           BANK OF MONTREAL, a Canadian bank



                                           By
                                             -----------------------------------
                                             Title:


NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                           INITIALED:

                                           --------
                                           Borrower

                                       11

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<PAGE>

<TABLE>
<CAPTION>

                                    Exhibit A
                                       to
                               FIRST AMENDMENT TO
                         1997 REVOLVING CREDIT AGREEMENT

                                                               Maximum Amount
                                               Converted       Available Under
Bank                Pro Rata %                 Note Amount   Revolving Facility*
----------          ----------                 -----------   -------------------

<S>                      <C>                   <C>                   <C>
FNB-O                    20.7%                 $ 7,866,000           $ 6,831,000
FNB-W                      .5%                     190,000               165,000
NBD                      11.9%                   4,522,000             3,927,000
Norwest                  4.8 %                   1,824,000             1,584,000
LaSalle                  19.9%                   7,562,000             6,567,000
Sumitomo                 10.0%                   3,800,000             3,300,000
Mercantile               10.3%                   3,914,000             3,399,000
Montreal                 11.6%                   4,408,000             3,828,000
First Bank               10.3%                   3,914,000             3,399,000
                     ---------                ------------

                                               $38,000,000           $33,000,000


<FN>

*Includes current amounts outstanding after Conversion

</FN>
</TABLE>
                                       12

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