China refined 27.27 million tons of oil in December, down 2.3 percent year-on-year, as demand shrank and product inventories piled up, the country's top economic planner said in a statement Wednesday on a government website.

In November, China processed 29.79 million tons of oil, up 7 percent year-on-year.

Inventories at PetroChina and Sinopec, the two major oil refiners, hit record highs in December, the National Development and Reform Commission (NDRC) said, without giving details.