PRESS RELEASE March 4, 1999 Contact: Linda Grunberg Director of Public Relations Phone: 402-255-3748 Fax: 402-390-7188 Email: lindag@dtn.com Contact: Brian Larson Vice President and CFO Phone: 402-255-3757 Fax: 402-255-8227 DTN Amends Shareholder Rights Plan OMAHA, NEB - Data Transmission Network Corporation (DTN) (NASDAQ: DTLN) announced today that its Board of Directors has amended the Companys Shareholder Rights Plan to allow for the purchase of up to 15 percent of the Companys common stock before the rights under the plan become exercisable. Prior to this amendment, the rights generally became exercisable if a person or group acquired 11 percent or more of DTNs common stock or announced a tender offer for 11 percent or more of DTNs common stock. As amended, the Plan allows a person or group to acquire greater than 15% (but not more than 20%) of DTNs common stock with a voting trust agreement with the Board of Directors. This action by DTNs Board of Directors came about as a result of conversations with an investor interested in acquiring greater than 11 percent of the Company. The Shareholder Rights Plan was implemented in August of 1997 and is designed to assure that all stockholders receive fair and equal treatment in the event of any proposed takeover of the Company. It also guards against partial tender offers, open market accumulations and other abusive tactics to gain control of the Company which might provide inadequate value to stockholders. -more- - 11 - Data Transmission Network Corporation (NASDAQ: DTLN) in Omaha, Nebraska, is an innovative information and communication provider for a variety of industries including agriculture, financial, energy and weather-related industries. Additional industries served include automotive, electrical equipment and freight transportation. DTN is committed to providing comprehensive, time sensitive and affordably priced information including weather, news, quotes, market analysis and commentary to more than 159,000 subscribers in the U.S. and Canada via all relevant distribution technologies. Visit the DTN Web site for company and investor information at www.dtn.com. #### 2 - 12 -