BEIJING, July 24 (Xinhua) -- About 40 percent of the total foreign investment of the Republic of Korea (ROK) went into China last year, according to an ROK economist.

    ROK investment in China has increased rapidly along with bilateral trade, said Joon Kyung Kim, deputy director of the ROK's Development and Study Institute.

    He said 85 percent of investment focused on electronics manufacturing, mostly in east China's Shandong Province, followed by Jiangsu Province and Tianjin Municipality.

    The main investment form was assembly cooperation and trade, involving the export manufactured parts to China for assembly into completed products to be sold in China or exported.

    "This will also be the main form of future investment in China's west," Joon told an economic forum in Nanning, capital of south China's Guangxi Zhuang Autonomous Region.

    The United States was the ROK's top market for parts exports in the 1990s, and in 1995 exports of manufactured parts to China was only two percent of the total.

    But China became the largest market, accounting for 29 percent of parts exports last year.

    China and the ROK established diplomatic ties in 1992, and China has become the ROK's largest trade partner and investment target country.

    Last year, bilateral trade surpassed 100 billion U.S. dollars. In the first quarter of this year, it exceeded 26 billion dollars in value.