The Chinese mainland has become Taiwan's largest market, said authorities with the Office of Taiwan Affairs under the State Council on Tuesday.

By 2005, total trade value between the mainland and Taiwan had reached US$ 537 billion, in which Taiwan's exports to the mainland exceeded US$ 414 billion.

Taiwan has launched 68,095 investment projects on the mainland during the past 20 years, with a contract value of US$ 94 billion. Most of the projects are in east China and the coastal areas in south China like the Pearl River delta. The fields of investment are expanding from information manufacturing to service sectors like financing and shipping.

At a forum on industrial development between both sides of the Taiwan Straits, which opened in Nanning, capital of the Guangxi Zhuang Autonomous Region, on Tuesday, over 200 participants from both Taiwan and the mainland called for more cooperation between the two sides.

"Trade between both sides has reached such a large scale that high-level cooperation is needed," said Zhou Huaizhi, vice director of the Taiwan Research Office under the Chinese Academy of Social Sciences.