AT&T Corp. and British Telecommunications have made a basic agreement with Japan Telecom Co. to buy 15 percent stakes in the firm, sources said Thursday.

The stakes will be acquired from a new share allocation by Japan Telecom and provide the western firms with seats on Japan Telecom's board of directors, according to the sources.

Japan Telecom is the third-largest long-distance and international long-distance carrier in the nation. The three companies, the sources said, may combine their Japanese operations to provide data telecommunications services to multinational businesses.