SHANGHAI, Apr. 7 -- China has extended the list of banned items to include more commodities which will not be allowed to be imported or exported if they are used for processing purposes.

The ban now covers an addition of 186 goods, including some crude products such as heavy diesel oil and fuel oil, which underscores the latest state effort to tighten trading of such nonrenewable resource-related commodities.

Other affected products include certain timber products, fertilizers as well as furs of certain endangered species.

This put the total number of products that are banned in the processing trade to 990, according to the updated list issued on Thursday by the Ministry of Commerce, the General Administration of Customs and the State Environmental Protection Administration.

The new list will become effective from April 26.

The processing trade refers to imports of raw materials or semi-finished goods for processing and then exporting the finished products.

Banning processing trade companies from importing and exporting such energy products could also help restrain China's rapid growth in crude imports, which some analysts have alleged is pushing up global oil prices.

The processing trade, which plays a key role in China's foreign trade, totaled US$831.9 billion in 2006, a 21 percent increase from a year before, and 47 percent of its total imports and exports, according to official data.

The government has been updating the list to improve the structure of foreign trade.