Dallas, Tex. and Clinton, Miss. - January 3, 2002 - Allegiance Telecom, Inc. (Nasdaq: ALGX) today announced that it has acquired substantially all of the Intermedia Business Internet (IBI) assets from WorldCom, Inc. (Nasdaq: WCOM, MCIT). Terms of the deal were not disclosed but Allegiance and WorldCom confirmed that the transaction is not a financially material event for either company.

WorldCom was obligated to sell the IBI assets pursuant to a consent decree entered into by WorldCom and Intermedia in connection with their merger last year.

About Allegiance Telecom, Inc.
Allegiance Telecom (NASDAQ: ALGX) provides its business customers with a complete package of telecommunications services, including local, long distance, international calling, high-speed data transmission, Internet connectivity and Web hosting services.

About WorldCom, Inc.
WorldCom, Inc. (NASDAQ: WCOM, MCIT) is a preeminent global communications company for the digital generation, generation d, operating in more than 65 countries with 2000 revenues of approximately $35 billion. WorldCom provides the innovative technologies and services that are the foundation for business in the 21st century. For more information, go to www.worldcom.com.