China's coal imports surged to a monthly record of 17.34 million tons in December, up 25 percent compared with the previous month.

That's according to data supplied by the China Customs Statistics (CCS) Information Center on Wednesday.

December's robust numbers mean the country's full-year coal imports were a record 166.16 million tons in 2010, a 32 percent jump from the 125.83 million tons posted in 2009, according to Reuters calculations.

Some analysts said the strong surge in imports - partly prompted by a demand surge during the harsh winter months in the first quarter and large price differentials in the second - would set the tone for 2011.

Net coal imports for 2010 are also expected to exceed analysts' expectations of 133.5 million tons, according to a median prediction of 10 analysts polled in late November.

It was not clear how much of December's record imports comprised coking coal, but cold weather in the last two months has strained power supplies and pushed coal stocks at power generators to dangerously low levels in some provinces.

The previous monthly high was 16.4 million tons in December 2009. Shipments to China, the world's top producer of coal, have surged since 2008 after output in Shanxi and Shaanxi, its top two coal mining provinces, slowed on the back of a consolidation drive.

Limited rail capacity, which is already facing severe capacity constraints, has also choked supplies from the coal-producing northern regions to key demand centers in southern provinces, in turn encouraging coastal cities to turn to imports.

China imported 460,000 tonnes of diesel in December, nearly five times the year-ago level, data showed, as the world's top energy consumer battled a shortage of the fuel.

Gasoline exports last month were about 360,000 tonnes, versus 485,622 tonnes a year ago, data from CCS showed.

On Tuesday, Premier Wen Jiabao called for more diesel supplies and efforts to ensure normal power and natural gas supplies in the first quarter.

China's diesel shortage, caused when power users switched to diesel generators to skirt a crackdown on coal-fired power, has eased after the government raised fuel prices last month and refiners produced a record amount of fuel and slashed exports.

Combined inventories of gasoline, diesel and kerosene held by China's top two oil firms gained about 6 percent in November versus October, reversing declines in the previous eight months, as refiners raised production to record rates, slashed exports and boosted imports in response to the diesel shortage.

CCS is the official supplier of Chinese customs data outside China.