China, the world's top coal importer, will levy import tariffs on the commodity for the first time in nearly a decade.

News of the tariffs – three per cent on anthracite coal and coking coal and six per cent on non-coking coal – hit mining stocks around the world.

Vancouver-based Teck Resources, one of Canada’s largest coal suppliers to China, saw its stock slide by 6.4 per cent to $18.07 in late trading.

Coal represented 44 per cent of Teck’s revenue in 2012 and it sells $2.5 billion in commodities to China every year, including coal, copper and zinc.

China changed its rules after intense lobbying by the domestic coal industry, which wants preferred access to the market, especially China’s steel-making industry.

It had eliminated all tariffs on coal in 2007. Australia and Russia are also big suppliers of coal to China, but Indonesia, another big supplier, is exempt from the tariffs because it has a free-trade agreement with China.

Global coal prices have slumped a miners brought on new supply in the past few years, assuming rapid growth of China's coal imports. Prices are now at 111 a tonne, down from $156 a tonne a year earlier.

Teck reported a sharp drop in earnings in the second quarter because of “significantly” lower coal prices.

In the U.S., Morgan Stanley analysts downgraded the entire coal sector. Peabody Energy dropped 72 cents, or 7 per cent, to $10.54. Arch Coal dropped 8 cents, or 5 per cent, to $1.58 and Walter Energy fell 14 cents, or 8 per cent, to $1.74.