Sony Corp. said Thursday its operating profit dropped 13 percent on a year-on-year basis to 138.2 billion yen in the October-December period, dragged down by weak sales of conventional televisions and portable audio products.

Katsumi Ihara, the firm's chief strategy officer, told a news conference that Sony will rejuvenate its core consumer electronics business by boosting its display operations, focusing on liquid crystal display TVs and rear-projection TVs.

During the third quarter of fiscal 2004, revenue was down 7.5 percent to 2.15 trillion yen. Net profit in the period jumped 55 percent to 143.8 billion yen, though this was mostly due to lower tax expenses in the United States.