Oct 24 (Reuters) - China has set the 2012 non-state crude oil import quota at 29.1 million tonnes, the same as this year, the Ministry of Commerce said on Monday.

The amount, equivalent to about 12.2 percent of China's total crude imports last year, will be alloted to traders outside the dominant four state traders -- Unipec, Chinaoil, Sinochem and Zhuhai Zhenrong -- but these non-state traders will have to sell back the crude they import to the oil duopoly Sinopec and PetroChina .

These so called "non-state" traders for crude oil imports are mostly affiliates to the oil duopoly, traders have said.

Earlier this month, the ministry set the non-state fuel oil import quota at 16.2 million tonnes for 2012, unchanged from 2011.

China has been increasing the amount of crude and refined fuels that non-state firms can import by 15 percent every year for 10 years until 2011 under its commitment to the World Trade Organization (WTO).

But the quotas were more of a protocol than an indication of real market opening, as the import business remains dominated by powerful state oil firms and tough requirements actually prevent private oil firms from entering the trade business. (Reporting by Judy Hua and Chen Aizhu; Editing by Jacqueline Wong)