The Shaw Group Inc. announced Thursday that it was refused permission to redeem the bonds used to finance its Westinghouse Group acquisition, which means the debt will not come off Shaw’s books until March 2013.

In September, Shaw said it planned to sell its 20 percent piece of Westinghouse to majority owner Toshiba Corp. The move would allow Shaw to lop off close to $1.7 billion of debt, while allowing the construction giant to continue working with Westinghouse.

In 2006, Shaw issued $1.1 billion in yen-backed bonds to buy its piece of Westinghouse. But the yen’s increasing strength against the dollar turned the original $1.1 billion debt into close to $1.7 billion in September.

The Westinghouse deal included an option allowing Shaw to sell its stake to Toshiba between March 2010 and March 2013. With the early sale request rejected, the option will now be exercised automatically on Oct. 6, 2012.

The proceeds from the bond sale will be used to repay the bonds in full on March 15, 2013.