In a move to secure a foothold in the Japanese market, cellphone operator Vodafone Group PLC of Britain said Wednesday that it has signed a contract to acquire 15 percent of Japan Telecom Co.'s outstanding stocks from two Japan Railway group firms.

The 249.2 billion yen deal will make Vodafone the second-largest shareholder of Japan Telecom along with British Telecommunications PLC and AT&T Corp. of the United States, each owning 15 percent.

East Japan Railway Co. remains the top stakeholder with 15.1 percent.