Lucent Technologies' Enterprise Network Group has hired FCB Worldwide, San Francisco, to handle its planned $50 million advertising campaign. The move comes in advance of a planned spin-off of the Enterprise Network Group, Murray Hill, N.J., later this year. The Enterprise Network Group specializes in the development of software and services for corporate voice and data messaging, customer relationship management systems and call centers. It has about $8 billion in annual revenues. FCB New York will support the San Francisco office of FCB Worldwide, while FCB's international operations will manage advertising in selected international markets.