Sony expects its annual loss to swell to more than $2 billion after writing down the value of its troubled mobile business as phone sales sagged amid brutal competition.

The Japanese electronics and entertainment conglomerate said Wednesday, Sept 17, it anticipates a net loss of 230 billion yen ($2.15 billion) for the fiscal year that ends March 31, 2015. Its previous forecast was for a 50 billion yen ($466 million) net loss.

Sony has been trying to reshape its business after years of losses. It said the bigger loss stems from a lower accounting valuation of its mobile phone business due to weaker than expected sales. The company is recording a "goodwill impairment charge" of 180 billion yen ($1.7 billion) in the July-September quarter. Sony left its full-year sales forecast unchanged at 7.8 trillion yen ($72.8 billion).

Sony reported a 128.4 billion yen loss in the fiscal year that ended March 31.

The profit warning follows a surprise eightfold jump in Sony's quarterly profit in July thanks to gains from selling buildings and its stake in a video-game maker.