BEIJING - The Ministry of Commerce on Wednesday issued a guideline encouraging private oil companies to take part in refined oil's processing, transportation and retail.

The government will support competitive and large companies to integrate into asset-based oil groups and technology service-based oil companies, according to the guideline.

Private business will be encouraged to obtain stable access to refined oil resources, technology and management service.

China's refined oil market is largely controlled by three State-owned heavyweights: PetroChina, the largest oil producer in Asia; Sinopec, the top oil refiner; and CNOOC, the offshore oil producer. Private oil companies have long been elbowed out of the market.