Toshiba Corp. will buy Shaw Group Inc.'s 20 percent stake in nuclear-plant designer Westinghouse Electric for about $1.6 billion, increasing its share to 87 percent.
Shaw is exercising its option to sell the stake to Toshiba after a rise in the value of the yen helped to boost its Westinghouse debt by more than 50 percent during the past five years, according to a statement Tuesday.
The option to sell was part of the companies' 2006 purchase of Westinghouse.