This includes a requirement for refineries of alumina - the raw material to make aluminium - to reduce production by at least 30 percent.

This is likely to deepen shortages of alumina and further push up prices.

Below are some of the details that have started to come out about the precise cutbacks.

HONGQIAO - On top of its aluminium cuts, China Hongqiao Group (>> China Hongqiao Group Ltd), the world's top aluminium producer, must - together with another alumina plant in Binzhou, Shandong province - cut their combined 8 million tonnes of annual alumina production by 2.5 million tonnes from Nov. 15 to March 15, 2018.

XINFA - In Liaocheng, also in Shandong, Xinfa Group must cut its 7 million tonnes of annual alumina production by 2.6 million tonnes over the same period.

CHALCO SHANDONG - Also in Shandong province, a document from the city of Zibo reviewed by Reuters showed 30 percent cuts to be made at Chalco Shandong, a unit of Aluminium Corp of China (>> Aluminum Corporation of China Limited), whose overall listed capacity totalled 1.773 million tonnes per year.

ZHONGZHOU - Jiaozuo City in Henan province launched capacity cuts almost two months ahead the scheduled winter cutback set for Nov. 15. The city ordered Zhongzhou Aluminium, an alumina refinery belonging to Chalco, to cut over 30 percent of its capacity, which is 2.81 million tonnes, it said on its website.

(Reporting by Tom Daly in Beijing, editing by David Evans)