Beijing (AP): Archaeologists will salvage a porcelain-laden ship that is believed to have sunk off the coast of southern China some 400 years ago, state media said on Wednesday, hoping to find out more about foreign trade during a period when the country tried to close itself off to the world.

The ship is thought to be a merchant vessel and could contain some 10,000 pieces of porcelain, most made during the reign of Emperor Wanli (1572-1620) in the latter part of the Ming Dynasty, the official Xinhua News Agency said.

About 200 pieces have already been recovered and some date back to the Song Dynasty (960-1279), Xinhua said.

"It is a very interesting finding because, under the rule of Emperor Wanli, China imposed a ban on sea trade,'' Cui Yong, an archaeologist with the Guangdong Provincial Institute of Archaeology and Relics, was quoted as saying. ``The excavation of the ship will help us learn more about China's foreign trade at that time.''

Southern China's Guangdong province will organize an excavation team later this year for the 33 foot- (10 meter-) long ship that lies about 5.6 nautical miles offshore from Shantou city, Xinhua said.

Despite historically sending ships throughout Southeast Asia and as far as Africa, China ordered an end to maritime exploration in the beginning of the sixteenth century, just as European powers sought to expand trade throughout the world, buoyed by economic development and industrialization.

The ship is probably from Guangdong, Cui was cited as saying, because the porcelain found so far was produced by workshops there. The province was also a major center of sea trade in ancient China.

The ship was found by local fishermen in 2007, Xinhua said. The area surrounding the ship has been cordoned off and monitored by radar to prevent the cargo being stolen, the agency reported, citing police who said they have stopped about 50 suspicious boats.