NATION : MCI Wins $150-Million Contract

MCI Communications Corp. has won its biggest contract ever, a five-year, $150-million deal to provide Merrill Lynch & Co. Inc. with a worldwide network for voice and data communications, the companies said today.

The deal is the latest in a series of such links, as big phone customers turn over the construction of state-of-the-art international networks to big phone companies.

General Electric Co. said last week it had selected American Telephone & Telegraph Co., British Telecom and France Telecom to build the first phase of its international network.