Oct 18 (Reuters) - China has asked its state-owned gas importers to stop reselling liquefied natural gas (LNG) to buyers in Europe and Asia as it seeks to ensure its own supply for the winter season, Bloomberg News reported on Monday.

Halting LNG resales could create more supply issues for Europe, which has benefited from redirected cargoes to make up the shortfall after pipeline gas supplies from Russia have been curtailed amid the Ukraine conflict.

China's National Development and Reform Commission (NDRC) has asked PetroChina Co, Sinopec and Cnooc Ltd to keep winter cargoes for domestic use, the report said, citing people familiar with the matter.

The commission did not respond to a faxed request for comment. PetroChina, Sinopec and Cnooc did not respond to Reuters' requests for comment.

China's LNG importers were intending to stay out of the spot market this winter as gas demand growth has skidded to the slowest since 2002, easing competition for the fuel with Europe though state oil giants were still expected to bring in spot cargoes to fill any supply deficit.

Without confirming whether the government was mandating a halt to the resales, two Beijing-based gas industry sources said on Tuesday it is a fair request from the NDRC to preempt a domestic shortage as the need to meet winter heating consumption is set to boost LNG demand.

The government typically allocates an approximate number of LNG shipments for each state firm to bring in during the winter heating season from mid-October through mid-March to preempt a supply gap in case pipeline gas supplies fall unexpectedly short, the sources said.

"Basically companies are requested to meet the overall volumes set by the government," said one of the sources, an official at a state gas company.

But that does not rule out swapping out shipments secured under term contracts for trading optimization, the sources added.

The government was rather targeting re-selling purely for profits, they added.

Chinese authorities reiterated the policy of ensuring supplies and stabilising prices of raw materials on Monday as part of the Communist Party Congress taking place this week, saying the country would increase domestic energy supply capacity and reserve capacity for key commodities. (Reporting by Jose Joseph and Akriti Sharma in Bengaluru; additional reporting by Chen Aizhu in Singapore Editing by Mark Potter and Christian Schmollinger)