* December gas imports hit new high
* Record LNG imports, C. Asia imports higher
* 2017 crude imports up by 770,000 bpd, beat expectation -analyst
* Dec refined fuel exports at record high (Adds comment on crude oil, details on record fuel exports)
BEIJING, Jan 12 (Reuters) - China's natural gas imports soared to a record in December as the country battled a winter supply crunch, while crude oil imports eased sharply from near-record highs a month earlier, customs data showed on Friday.
December gas imports, including pipeline imports and tanker shipments of liquefied natural gas (LNG), came in at 7.89 million tonnes, 20 percent above November's previous record of 6.55 million tonnes, data from the General Administration of Customs showed.
Imports for the whole of 2017 jumped 27 percent from 2016 to a record of 68.57 million tonnes.
A massive government push to heat millions of homes and power thousands of factories with natural gas in northern China has led to demand for the fuel outpacing supply, while delivery infrastructure has found it hard to cope.
"LNG imports last month reached new highs according to our cargo monitoring and pipeline imports from Kazakhstan and Turkmenistan also ramped from previous month," said Diao Zhouwei, analyst of IHS Markit.
Record imports by state energy firms and higher Chinese production have pushed down domestic wholesale LNG prices in north China. Prices were around 5,500 yuan ($848.44) per tonne this week, off 45 percent from peaks seen in late December.
December's crude oil imports hit 33.7 million tonnes, or about 7.94 million barrels per day (bpd). That was down 12 percent from November's 9.01 million bpd, the second-highest level on record.
Buying eased in December as refiners and fuel distributors drew on inventories after hefty stockpiling in the previous month, said Seng-Yick Tee, analyst with SIA Energy.
Imports of crude oil for 2017 were up 10.1 percent over the previous year at a record 419.6 million tonnes, or 8.39 million bpd, up 770,000 bpd, according to Reuters calculations.
The import growth was fueled for the second year in a row by independent refineries as the government allowed more firms to import crude, although some of them were forced to scale back operations as authorities stepped up environmental checks.
SIA Energy's Tee said the 770,000 bpd increases in last year's imports exceeded his forecasts, suggesting China's domestic fuel demand may be stronger than official data showed.
"Given no big surge in fuel exports and mild stock builds in strategic (crude oil) reserves, the crude data points to under-estimates in domestic fuel productions," Tee said.
Refiners churned out a sizeable amount of blending components, such as mixed aromatics and diesel substitute "raw white oil," that are not captured in official output data, Tee said.
Declining oil output at home also contributed to the demand for overseas purchases.
Daqing oilfield, the country's largest, recorded a 7 percent fall in 2017 output versus the previous year, as operator PetroChina scaled back high-cost production at the aging field.
Meanwhile China in December exported a record high 6.17 million tonnes of refined fuel, beating the previous peak of 5.79 million tonnes set in November. Total annual oil product exports last year hit 52.2 million tonnes, up 8 percent over 2016.
The rush to export over the last two months of 2017 was spurred by additional quotas from the government.
Fuel imports last year rose 6.4 percent to 29.64 million tonnes. (tonne=7.3 barrels of crude oil) ($1 = 6.4825 Chinese yuan renminbi) (Reporting by Chen Aizhu; Editing by Richard Pullin and Kenneth Maxwell)