Earlier this month, Sony Chairman Howard Stringer apologized for last month's incursion by hackers.

Nine Sony electronics factories in northeastern Japan that had been disrupted by the natural disaster in March have resumed operations, the company said on April 28. Other plants had to curtail production because of material and component shortages.

In the latest announcement, Sony also said it had insurance policies that cover certain damages to fixed assets and inventories, as well as associated restoration costs. That would offset almost all the losses and expenses in the year just ended, "as the recoveries from insurance claims are deemed probable."