Toshiba is currently in talks to acquire Shaw Group's 20% interest in nuclear power plant company Westinghouse Electric Co.
In 2006, engineering services company Shaw partnered with Toshiba and Japanese engineering firm IHI to buy Westinghouse from British Nuclear Fuels for $5.4bn.
Toshiba acquired a 77% stake in the company while Shaw purchased 20% and IHI took 3% respectively.
Under the earlier agreement, Shaw has the option to sell all or part of its stake to Toshiba before the 6.5-year maturity of the bonds.
US-based Westinghouse Electric provides fuel, technology and equipment to utilities for commercial nuclear power use, reports the Wall Street Journal.