Mr. Armstrong, a former senior executive at I.B.M., has since 1992 changed Hughes from a lumbering commercial electronics operation into a fast-growing unit that has made digital satellite television systems its flagship product line.

As expected, AT&T announced plans to issue a tracking stock for its fast-growing wireless unit that would trade separately from AT&T's common stock, which is among the most widely held in the nation.

Mr. Roscitt, chief executive of AT&T's fast-growing unit that runs networks for the company's largest corporate customers, will be named head of the unit that oversees all the needs of business customers.

Chagrined that investors were not giving AT&T full financial credit for the value of the company's fast-growing wireless unit, AT&T said last year that it would issue a separately traded "tracking stock" meant to represent its wireless operation.

Last year, the fast-growing unit posted revenue of $1.9 billion.

WorldCom would have moved closer to that vision had it succeeded in acquiring Sprint, which is coveted for its fast-growing wireless unit and its capability of handling large amounts of data over its Internet network.

Yet unlike its competitors, British Telecommunications has been slow to spin off fast-growing units to foot the bill.

And in some ways that task is expected to become even tougher through the end of 2001 because AT&T will lose the ability to use its fast-growing wireless unit to buoy its overall financial results.

General Motors acquired Hughes Aircraft in 1985 and has sought ways to unlock the value of the fast-growing unit, whose coveted satellite TV operation known as DirecTV has 9.5 million subscribers.

Top executives at AT&T are planning to create a separately traded tracking stock for the company's fast-growing cellular unit and to invest billions to deliver high-speed Internet access and local phone service to millions of American homes using wireless technology.