The company cut its annual net profit forecast by 29 percent to ¥25 billion, or $229 million, citing higher-than-expected taxes and ballooning losses at a heavy machinery joint venture.

It also deepened loss estimates from its ailing personal computer business to ¥21 billion from an earlier estimate of ¥8 billion.

It unveiled a series of measures in September intended to turn around the PC business and fend off heavy price competition from industry leaders Hewlett-Packard and Dell in North America.

Group net profit for the July-September quarter was ¥4.67 billion, against a year-ago loss of ¥7.61 billion. Revenue rose 3.3 percent to ¥1.49 trillion.

The one sector that comes to rescue for Toshiba is its semiconductor business. Surging sales of digital cameras and photo-snapping mobile phones drive up demand for NAND-type flash memories and put the company's report card in black.