Rare-earth metals are used in large quantities in permanent-magnet generators (PMG) for next-generation wind turbines. China controls an estimated 97% of the world's processed rare- earth metals and is the leading maker of rare-earth permanent magnets.
The move was reported in official newspaper China Daily. It cited an unnamed Ministry of Commerce representative.
The latest cut in export quotas comes just four days after the US Trade Representative said his office will probe China's allegedly illegal "protective" behavior over its clean-energy industries, including wind.
The complaint, filed by the United Steelworkers trade union, cites among other things China's reduced rare-earth export quotas.
China has been steadily cutting export quotas of rare-earth metals by 10% to 15% yearly for about five years.
More recently, China reduced 2010 production levels of rare-earth metals and slashed export quotas by a massive 72 percent for the second half of 2010, says China Daily, citing official data.
Many leading wind turbine manufacturers use rare-earth based PMGs. These include Siemens, Vestas and China's largest wind turbine manufacturer, Goldwind. A high-energy PMG for a 3.5MW turbine could use 2,000 kg (4,400 lbs) of rare-earth or neodymium-based alloy.