Toshiba Corp. plans to book an impairment loss of around ¥300 billion for fiscal 2015 linked to its U.S. nuclear power subsidiary Westinghouse Electric Co., sources familiar with the matter said Friday. The loss would be larger than anticipated.

The struggling electronics maker, mired in a massive accounting scandal, had previously been thought to be booking a charge of around ¥200 billion for the year.

The issue relates to ¥350 billion in goodwill that Toshiba booked when acquiring Westinghouse in 2006. That figure could now be slashed to less than half if Toshiba books the impairment loss, the sources said.

Westinghouse booked impairment losses in fiscal 2012 and 2013 of around $1.32 billion over other aspects of its nuclear power plant construction and maintenance business after the 2011 Fukushima nuclear crisis.

Toshiba has been criticized, however, for not disclosing its accounting treatment for Westinghouse.