Toshiba confirmed it expects to book a 712.5 billion yen ($6.3 billion) writedown in its nuclear power business, citing cost overruns at its Westinghouse business. In addition, Shigenori Shiga will step down as chairman of the conglomerate.

The charge will result in a provisional 500 billion yen loss for the nine months through Dec. 31, the company said in a statement Tuesday.

Toshiba confuzed investors on Tuesday when the company missed its own deadline for announcing earnings.

Toshiba is also considering all options for its NAND flash memory unit as it tries to raise cash, including a complete sale, CEO Satoshi Tsunakawa said at a briefing. The company has previously planned to limit the sale to 20 percent to maintain control.

Toshiba's $5.4 billion acquisition of Westinghouse in 2006 was a bet on the future of nuclear power and a way to balance volatility of chip operations with steady long-term revenues. The vision has soured after the 2011 Fukushima meltdown damped demand and the company's next-generation AP1000 modular reactor technology proved difficult to implement.