Sony, which posted a record net loss in the year to March 31, said it will complete the investment by September 2013 at its CMOS image sensor plant in Nagasaki in southern Japan, with half the money to be spent during the current business term as part of outlays already announced.

Output at the plant will be 60,000 wafers a month once it has established new production lines, the company said. These will be sold to makers of smart phones and tablets and will also be used for Sony's own products.

With its television unit hammered by weak demand and intense competition from foreign rivals such as Samsung Electronics the company is looking for ways to boost revenue and profits in other divisions.

Sony expects sales at its TV unit, which has lost more than $12 billion in 9 years, to fall 11 percent to 17.5 million this business year.

The company's new president, Kazuo Hirai, in April said that Sony's future lay in mobile devices such as the Xperia smartphone, gaming and digital imaging. He set a target for group sales of 8.5 trillion yen in two years, with an operating margin of more than 5 percent.

(Reporting by Tim Kelly and Miki Kayaoka; Editing by Ramya Venugopal)

• A Permanent Economic Emergency