The volume consists of 12 million tons of refined products quotas, made up of kerosene, diesel and gasoline exports, and 3 million tons of marine fuel, the sources said.

The quotas were allotted to Sinopec, PetroChina, CNOOC, Sinochem Group, China Aviation Oil Co, Zhejiang Petrochemical Co and Norinco, China-based consultancies Longzhong and JLC said.

The new issue brings the total volume of oil product export quotas this year to 53.99 million tons, up from 34.75 million issued in the same period last year.

Previous batches this year comprised 12 million tons in May and 26.99 million in January.

State-owned Sinopec, PetroChina, CNOOC and Sinochem Group were the main recipients of the quotas, taking 91.6% of the allocation across refined fuel products and marine fuel, according to a calculation by Reuters.

Zhejiang Petrochemical Co, China's largest private refiner, received a total of 1.06 million tons, according to a filing released by its parent company, Rongsheng Petrochemical, on the Shenzhen stock exchange.

Sinopec, PetroChina and Sinochem did not immediately respond to requests for comment.

Representatives for CNOOC stated that the export of refined products was not part of the group's main business activities.

The Ministry of Commerce did not immediately respond to a faxed request for comment.

Market participants had initially expected the announcement of the quotas in the first half of August.

"Given the longer wait and rumours of quotas hitting between 10 million and 20 million tons, this final figure is pretty within expectations and on the lower end of range," said Vortexa's China oil analyst Emma Li.

The slightly later timing of this third batch of quotas suggested that more surprises in the remainder of the year were unlikely, she added.

The volumes for each refiner will be unlikely to have exact product splits, allowing them to maximise profits by trading whichever fuel is most profitable at any time, two China-based trading sources said.