LONDON (Bloomberg) - Griffin Mining Ltd., a Bermuda-based company mining zinc in China, slumped the most in more than six years after saying profit will miss analysts' estimates as it suspends sales of the metal this year.

The shares declined 17 percent yesterday after Griffin halted shipments of zinc concentrates because rising exports from Chinese producers have pushed market prices lower. The contract for three-month delivery on the London Metal Exchange has dropped 46 percent this year.

Griffin is "stockpiling zinc concentrate at Caijiaying in China in the short term rather than continuing sales at current prices," it said in a statement on the Regulatory News Service.

The shares fell 16.25 pence to 77 pence in London, valuing the Hamilton, Bermuda-based company at £201.4 million ($416.5 million). The stock has declined 28 percent this year.

Zinc prices will stay low until China ends a tax rebate for the country's exporters, Griffin said in the statement.

China's National Development and Reform Commission, the top economic planner, is studying a proposal to remove the five percent rebate on exports of high-grade zinc next year and impose taxes instead, Wang Gongmin, vice-chairman of the China Nonferrous Metals Industry Association, told a conference in Nanjing yesterday.