Korea Aerospace Industries Ltd. (KAI), South Korea's sole aircraft manufacturer, on Monday reported its second-quarter net profit plunged 80.3 percent from a year earlier mainly due to investment in new businesses.

Net profit for the three months ended in June was 9.9 billion won (US$7.6 million), according to the company's regulatory filing.

The operating income for the April-June period fell 75.6 percent on-year to 8.4 billion won, while sales increased 9.7 percent to 733.5 billion won.

KAI said its major businesses, including developing the country's homegrown KF-21 fighter jet, are doing okay, and its aircraft body business is recovering.

KAI added that it won contracts worth 247.9 billion won in the second quarter, up 85.8 percent from a year ago.

But the company said its operating profit decreased due to investment in new businesses, such as microsatellite development, and the cost to expand the country's helicopter market. (Yonhap)