Private refineries in Shandong province, which import about a third of the nation's fuel oil, have reduced processing to their lowest rate since April 2010, according to an industry website.

Refinery run rates dropped to 25.7 percent of their designed capacity in the week ended on Thursday, from 32.3 percent a week earlier, the Shandong-based Oilchem.net said in a statement on its website.

The company had surveyed plants with a combined annual capacity of 68.85 million metric tons, or 1.2 million barrels a day.