China's monthly exports of rare earth metals more than doubled in November to 2,090 tons, bouncing back after falling by more than three-quarters in October, data supplied by China Customs Statistics Information Center showed.

While the monthly volume remained at the second-lowest level since January, the value of exports continued to skyrocket, topping $121 million for the month.

That equates to an average export value of $57,903 per ton on a free on board basis, up from $42,255 in October and a fourfold rise since July, according to Reuters calculations.

The 17 rare earth elements are used in high-tech electronics, magnets and batteries, with applications in hybrid cars, renewable energy, computer monitors and weapons.

China controls 97 percent of global supplies of the elements but restricts exports with a quota, causing alarm among buyers in Japan, the United States and the European Union.

China slashed the export quota by 40 percent this year and plans to trim it further next year. It has already announced increased export taxes on rare earths in 2011.

Japanese companies complained of restrictions on shipments from late September amid a spat over disputed islands in the East China Sea.

Japan's trade minister had said he hoped shipments would resume in the latter part of November, although analysts expected the volume of trade to remain stagnant.

The November data showed China's total export volume in the first 11 months of this year was 35,075 tons. Although that is more than the quota of 30,258 tons, it may include some shipments made early in the year and sold under the 2009 quota.

The value of exports in January-November has jumped from $232.5 million last year to $630.5 million in 2010, a rise of 171 percent.
Outside China, rare earths suppliers include Australia's Lynas Corp. and Arafura Resources, AS Silmet of Estonia and U.S.-based producer Molycorp Inc.