Bell Atlantic Network Services Inc., a division of Bell Atlantic Corp., has been awarded a 10-year, $600 million contract by the Defense Department to modernize its telecommunications system in the Washington metropolitan area.

The Telecommunications Modernization Project (TEMPO) contract calls for Bell Atlantic's Chesapeake & Potomac Telephone companies serving Maryland, Virginia and the District to upgrade the government network using Integrated Services Digital Network (ISDN) technology. ISDN technology allows more information -- voice, data and video -- to be sent over regular copper telephone wires.

Under the contract, Bell Atlantic will work with American Telephone & Telegraph Co. to replace and modernize the department's existing system with an all-digital one.

Bell Atlantic said that it will set up a management center at the Pentagon to oversee the new system.

The Defense Department estimates that the new system will serve about 136,000 lines at the end of the first three-year modernization phase. By the end of the 10-year life of the contract, more than 160,000 lines should be connected.