Japan's Toshiba said on Tuesday that it booked an impairment charge of 260 billion yen ($2.34 billion) for the past fiscal year on the nuclear business, a much-anticipated move to address lingering doubts over its book-keeping.

Toshiba, however, raised its earnings estimates for the year ended in March as it booked a pretax profit of 590 billion yen from the sale of a medical equipment division to Canon. It now forecasts a group net loss of 470 billion yen, smaller than a 710 billion yen loss estimated earlier.

Reuters