AT&T Widens Internet Role

Deepening an alliance of titans of communications and technology, Microsoft Corp. said Thursday it will invest $5 billion in AT&T Corp. and AT&T said it will increase its use of Microsoft's software.

AT&T is the nation's No. 1 long-distance telephone company and is becoming the top cable TV business. Microsoft is the dominant maker of software for personal computers and is seeking to widen its role in the Internet.

Under the agreement announced Thursday morning, AT&T will expand its use of Microsoft software for advanced set-top devices, which provide access to telephone service and the Internet for cable TV users.

As speculation about such a deal has grown in recent days, worries have been voiced about the clout such an alliance could wield over basic communications services for consumers. But AT&T stressed that it is not ruling out similar agreements with other technology businesses, saying its arrangement with Microsoft is a "nonexclusive agreement."