DALLAS, TX, March 11, 1998 -- Daniel Yost has joined Allegiance Telecom, Inc. as president and chief operating officer of the Company.

Previously, Yost was president and chief operating officer of NETCOM On-Line Communication Services, Inc., a leading Internet service provider. At NETCOM, Yost was responsible for managing all aspects of domestic operations, including development and implementation of NETCOM's overall strategic direction. Prior to joining NETCOM, Yost was president of the Southwest region of AT&T Wireless Services, Inc. During his three-year tenure, the Southwest region reached record growth and plan performance. Yost also served as president of McCaw Cellular Communications/LIN Broadcasting in the Southwest region and was president, general manager and founder of MetroCel Cellular Telephone Company.

"Yost brings over 26 years of telecommunications and business experience to Allegiance," said Royce J. Holland, chairman and CEO of Allegiance Telecom. "He has a strong background in integrating voice and data communications services, which will be extremely valuable as we prepare to launch our first cities."

Allegiance Telecom, Inc. is a competitive local exchange carrier headquartered in Dallas, Texas. The Company offers businesses a full package of telecommunications services, including local, long distance, international calling, high-speed data transmission and Internet services. Allegiance is targeting 24 major metropolitan areas in the U.S. with its "one-stop shopping" approach. Markets scheduled for initial service in 1998 include Atlanta, Chicago, Dallas, Los Angeles and New York. The Company's web address is: www.allegiancetele.com.