Toshiba Corp said on Tuesday it would take a 712.5 billion yen ($6.28 billion) writedown on its U.S. nuclear business, wiping out its shareholder equity and dragging the company to a full-year loss. The company estimated a 390 billion yen ($3.44 billion) net loss for the year ending March 31, compared with a 460 billion yen loss a year earlier, following a 2015 accounting scandal. The results have yet to be approved by the company's auditor and have been released as guidance, Toshiba said.