China's coal imports leapt to a monthly record of 16.38 million tonnes in December, up 29.5 percent from November, sources said on Monday.

"December imports were 16.38 million tonnes," said one industry source who had seen figures from China's customs office, which are not due to be published until Thursday.

The previous monthly high was 16.073 million tonnes imported in June. Shipments to China, the world's top producer of coal, surged last year after output in Shanxi, its top coal mining province, slowed and demand in other parts of the world fell.

The imports surge was also partly caused by demand for coking coal from China's steelmakers, who ramped up production to unprecedented levels in 2009.

It was not clear how much of December's record imports were coking coal, but China has suffered unexpectedly cold weather in the last two months that has strained power supplies and pushed power generators' coal stocks dangerously low.

"The high imports were a result of insufficient supply in the domestic market. January is likely another month of high imports," said Lu PIng, an analyst at China Merchants Securities.

"High imports will probably stay at lofty levels until March."In the first 13 days of January, Shenhua Group, China's top coal producer, produced 7.08 million tonnes of coal for electricity generation, 2.97 million tonnes more than in the whole of December, Xinhua news agency reported on Monday.

On Jan 1-13 Shenhua's Huanghua port, one of the firm's two dedicated coal receiving hubs in north China, unloaded 68 ships carrying 2.196 million tonnes of coal for power generation.

In the first 15 days of January, total coal production was up 8 percent from a year before, while sales increased by 28 percent and the company transported 12 percent more coal by railway than in the same period of 2009.

Shenhua Group is the parent company of China Shenhua Energy Co Ltd.