Gary Weis, who has been serving as acting chief executive of

Concert

, a joint venture between

AT&T

(T) - Get Report

and

British Telecom

(BTY)

, has been named the permanent CEO.

Weis, 53, took the interim post when David Dorman, the former CEO, left on Dec. 1 to become the president of AT&T. Weis has served as senior vice president of AT&T's business services-global operations, with responsibility for data and IP networks.

He assumed his position at AT&T in April 1999, when AT&T acquired

IBM's

(IBM) - Get Report

IBM Global Network

.

Shares of AT&T rose 19 cents, or 0.9%, to $20.50 in recent

New York Stock Exchange

trading. British Telecom gained $3, or 3.3%, to $93.