It said the deals, signed at the Korea Business Plaza event on Monday and Tuesday, included a 40 million dollar pledge by Japan's Hoya Corp. to expand its Liquid Crystal Display (LCD) photomask facility in South Korea.

The names of three other investors could not be released due to the need to maintain corporate secrecy.

But the firms involved were a chemical company, a semiconductor parts maker and a shipping parts maker, said the government-run Korea Trade Investment Promotion Agency.

The agency also helped 20 small- and mid-sized firms and seven local governments to hold one-on-one talks with 93 Japanese companies that have expressed interest in investing in South Korea.

At the event, Commerce Minister Chung Sye-Kyun urged Japanese companies to increase their investment in his country, the commerce ministry said separately.

"Japanese (annual) investment in South Korea accounts for a mere two percent of its total investment abroad," Chung was quoted as saying.

"The proportion should be raised to a higher level so that it may be on par with Japan's trade volume with South Korea."