AGREEMENT FOR PURCHASE AND SALE OF CORPORATION ASSETS

         This is an  agreement  dated this          day of                     ,
199    for the purchase and sale of the assets hereafter listed of Northern Data
Communications, Inc. (hereafter "NDC"), and Market Quoters, Inc.
(hereafter "MQI") by Data Transmission Network, Inc. (hereafter "DTN").

                                     PURPOSE

         The purpose of this agreement is to set forth in written form the terms
and conditions pursuant to which DTN shall purchase the assets of NDC and MQI.

                                    RECITALS

         1.    The parties  hereto wish to accomplish  the sale and the purchase
of certain  assets  while,  at the same time,  minimizing  any  interruption  or
inconvenience  to the present  customers of NDC and MQI and to  accomplish  such
transaction  in a  manner  which is  nearly  transparent  to all  such  existing
customers.

         2.    To this end, NDC and MQI will be servicing customer  accounts for
a minimum period of three months or longer,  following  closing at the option of
DTN,  and DTN will be  reimbursing  NDC and MQI for  employee  costs  and  other
operational  costs  incurred by NDC and MQI during this  transitional  period of
conversion.  Continued  customer servicing after sale, during this transitionary
period is aimed at minimizing inconvenience or interruption to any customer.

         THEREFORE;  AND IN CONSIDERATION OF THE MUTUAL COVENANTS AND CONDITIONS
HEREAFTER SET FORTH, THE PARTIES AGREE AS FOLLOWS:

         1.     DTN shall purchase the assets of NDC and MQI which are set forth
in the next paragraph for a total purchase price of $750,000.00 of which 56%, or
$420,000.00,  shall be paid to MQI, and of which 44%, or  $330,000.00,  shall be
paid to NDC. The purchase price shall be paid as hereafter set forth at closing.

         2.     The assets to be  purchased  include,  but are not  limited  to,
all customer lists,  service  records,  customer  service  contracts,  equipment
lists,  software,  and magnetic data (hard disks) pertaining to the customers of
NDC and MQI, and all  equipment  utilized by said NDC and MQI in servicing  said
customer locations.

                  a.     Any customer equipment which is purchased hereunder
that is  compatible  with the DTN system shall be  considered  assets  purchased
under this agreement while any such customer  equipment which is  non-compatible
with the DTN system shall remain the property of the sellers, NDC and MQI. It is
the purpose of this  paragraph to make certain that each  customer is left whole
throughout this transaction.

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                  b.       Also  purchased  hereunder is any existing  equipment
that any  customer  would  require to continue to receive  market data via third
party software.

                  c.       Also included in the assets  purchased  hereunder are
one  service  van,  together  with  tools,  necessary  to  provide  service  and
switch-out.  Here,  it is  understood  that  MQI will  transfer  title of a 1993
Plymouth service van and said tools.

         3.     After closing, NDC and MQI shall  continue to service  customers
in the normal manner during a conversion  period,  the completion of which shall
be final once all customers have been switched to the necessary DTN hardware and
are  receiving  data via DTN. This  conversion  period is expected to last three
months,  and during this period, DTN agrees that DTN shall reimburse NDC and MQI
for employee costs and  operational  costs incurred during the transition by NDC
and MQI employees.  Attached  hereto,  marked Exhibit "A", and by this reference
made a part  hereof,  is a list  setting  forth the  names of said  transitional
employees and costs anticipated to be incurred.

         4.     DTN agrees that DTN shall employ Leonard Kotta and John Salewske
for a period  of two  years  commencing  with  closing  at an  annual  salary of
$48,000.00  each  if said  Leonard  Kotta  and  John  Salewske  so  choose  such
employment.

         5.     DTN agrees that DTN shall  interview  all MQI and NDC  employees
for the purpose of determining  whether employment offers will be extended after
closing.  DTN is not  responsible  for  any  severance  package  for  MQI or NDC
employees.

         6.     DTN shall  complete due diligence by December 31 with respect to
all items outlined in a certain  November 29, 1996 letter to Paul Hedberg.  This
agreement  shall  become  binding  upon  the  satisfactory   completion  of  due
diligence,  such satisfaction  shall be in the sole discretion of DTN. DTN shall
be satisfied if the information reviewed is materially accurate when compared to
information received from NDC and MQI prior to December 17, 1996.

         7.     Closing shall be on January 2, 1997, and the purchase price
shall be accomplished by a transfer of funds by wire. Wire  instructions are set
forth on Exhibit "B" hereto attached and by this reference made a part hereof.

         8.     As of the date of closing,  January 2, 1997,  all  receivables
less unearned credit shall be the property of DTN. DTN shall pay to NDC and MQI,
in  addition  to the  purchase  price,  the total of said  receivables  less any
unearned credit.  Said receivables,  together with said unearned credit, are set
forth on Exhibit "C" hereto attached and by this reference made a part hereof.

         9.     NDC and MQI shall  defend,  indemnify and hold DTN harmless and
free from any  actions,  claims,  proceedings  or  liabilities  arising from the
conduct of NDC or MQI prior to the date of closing (January 2, 1997).

         10.    This agreement shall enure to and be binding upon the successors
and assigns of the respective parties hereto.

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         11.    This agreement  represents the entire agreement of the parties.
Any prior agreements  between the parties hereto,  whether oral or written,  are
superseded hereby, and there are no oral or written collateral  representations,
agreements, or understandings.

         12.    For a period of two years Leonard Kotta and John Salewske,  and
for a period of three years Paul  Hedberg and Larry  Risedt,  following  date of
closing  shall not  directly or  indirectly  engage in a trader  business in the
United  States which  business  would  provide a service  similar to the service
currently  provided  by NDC and MQI.  Indirectly  shall  mean any type of entity
(Partnership,  corporation,  joint venture,  trust,  etc.) which is owned 20% or
more by one of the parties or their immediate ancestors and descendants.

         13.    This agreement may be executed in multiple counterparts, each
of which shall be deemed to be an original for all purposes.

                                  MARKET  QUOTERS,   INC.,  a Minnesota Corp.



                                  By:
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                                  Title:
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                                  NORTHERN DATA COMMUNICATIONS, INC.



                                  By:
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                                  Title:
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                                  DATA TRANSMISSION NETWORK
                                  CORPORATION, a Delaware Corporation




                                  By:
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                                  Title:
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