(Yicai Global) Sept. 20 -- A regional government in China has ordered aluminum companies to rein in production, thus propelling aluminum prices to a seven-year apex.

The main contract for aluminum closed at USD2,623.85 (CNY17,055) per ton, up 3.43 percent after reaching a peak of CNY17,145 per ton in August 2011.

Authorities in Jiaozuo in eastern Hebei province directed Jiaozuo Wanfang Aluminum Manufacturing Co. [SHE:000612] and Zhongzhou Aluminum Co. -- a subsidiary of Aluminum Corp. of China [HK:2600] -- to limit production by more than 30 percent from yesterday to next March 15 to reduce air pollution.

This indicates other districts in the cities of Beijing, Tianjin and in their adjacent Hebei province will likely follow suit, raising expectations that prices for the metal will climb in the fourth quarter, analysts said.