* Five N.Asian refiners will receive full supplies in Jan -sources
* Aramco has raised prices for all crude oil grades to Asia in Jan (Recasts on information from additional sources, adds detail)
TOKYO/SINGAPORE, Dec 11 (Reuters) - Saudi Arabia, the world's top oil exporter, will supply full contractual volumes of crude to five North Asian refiners in January, unchanged from the previous month, five sources with direct knowledge of the matter said on Monday.
Steady supply of Saudi oil to Asia will help meet robust demand in the region, with flows from places such as Europe and the United States slowing.
State oil company Saudi Aramco last week raised prices for all crude oil grades to Asia in January, in line with strong demand. The premium for flagship Arab Light crude was at its highest since September, 2014, Reuters data showed.
The OPEC producer supplied full contractual volumes of crude to at least three North Asian refiners for December loading. But it trimmed supplies to at least three Japanese buyers and one in South Korea by up to 10 percent across different Saudi crude grades for November loading as maintenance at oilfields reduced output.
At least one North Asian refiner had not received its monthly allocation yet, a source familiar with the matter said, but added that Saudi Arabia was seen as willing to meet buyer demands.
All sources declined to be identified as they were not authorized to speak with media. (Reporting by Osamu Tsukimori in TOKYO and Florence Tan in SINGAPORE; Editing by Joseph Radford)