China's rare-earth exports plunged 77 percent in October from a month earlier after the government slashed shipment quotas for the second half of this year to conserve resources.

As the world's biggest supplier, China exported 830 tons in October, a hefty drop from 3,660 tons in September, according to the country's General Administration of Customs.

The government in July cut this year's export quota by about 40 percent from 2009.

The quota for the second half is 72 percent less than the same period a year earlier.

By value, exports surged 170 percent to US$509.5 million in the first 10 months year on year, underscoring surging prices for the minerals which are vital in the manufacture of a wide range of products, from mobile phones, hybrid cars to wind turbines, and even missiles.

Vice Commerce Minister Chen Jian said on November 1 that China won't "dramatically" reduce export quotas next year.

Rare-earth extraction in developed countries has dwindled in the past decade following environmental concerns and price competition.

Since 2007, China has curbed exports as years of exploitation have led to wasted resources and pollution.