BEIJING - China exported 16,000 tonnes of rare earth to Japan in the first nine months of the year, equivalent to 49.8 percent of its total rare earth exports, the Ministry of Commerce (MOC) said Tuesday.

The figure was a 167-percent year-on-year rise, MOC spokesman Yao Jian said at a press conference.

Exports to the United States increased 5.5 percent year on year to 62 million tonnes during the same period, equivalent to 19 percent of China's total rare earth exports.

China exported 32,200 tonnes of rare earth in the first nine months of the year at an average price of $14,800 per tonne.

Yao said the Chinese government has tightened regulations concerning the development, production and export of rare earth out of concern for the environment.

China cut its 2010 rare earth export quota 39 percent year on year while rare earth development and production capacities were reduced by 25 percent and 23 percent, respectively, he said.

In addition, China has added a 15- to 25-percent export duty on rare earth exports while banning the export of 41 rare earth-related processed products.

China's restrictive policies have been criticized by Japan, the United States and European countries. They said China's restrictions on rare earth exports violate World Trade Organization rules. China refutes such claims.

"China's restrictive measures comply with WTO rules, as the steps were taken in the whole process of exploitation, production and export," Yao said.

China continued to export rare earth in recent years even as environmental pressures grew and resource-depletion approached, he added.

He said China hopes other rare earth-rich nations will develop their own resources while adding that China is ready to cooperate with other nations to mine and process rare earth in an environmentally-friendly way.

Rare earth is a key component in the manufacture of high-tech products ranging from computers to airplanes. But mining rare earth is a highly-polluting process.

With a 90 percent share of the world rare earth trade, China's export quotas are a sensitive issue. In early November, the MOC denied suggestions there would be a drastic reduction in 2011 rare earth export quotas.