DALLAS, TX, March 12, 1998 -- Allegiance Telecom, Inc. announced today that Daniel Yost, John J. Callahan and John B. Ehrenkranz were appointed to the Company's board of directors.

Yost is Allegiance's new president and chief operating officer and Callahan is the company's senior vice president of sales and marketing. Ehrenkranz is a principal at Morgan Stanley & Co., Inc. Ehrenkranz replaced Frank Sica of Morgan Stanley as a result of Sica's decision to resign from Morgan Stanley to pursue other interests.

Allegiance Telecom is a competitive local exchange carrier headquartered in Dallas, Texas. The Company offers businesses a complete 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.