SHANGHAI, Jun 29, 2010 (Dow Jones Commodities News via Comtex) -- Yunnan Copper Co. (000878.SZ) will suspend the operation of three copper blasts for nine months for a scheduled maintenance starting July 1, the company said in a statement Wednesday.

Output of refined copper and sulfuric acid will be affected, but the operation of other systems won't be hit, the company said, adding it will be able to complete this year's production plan, without providing details.

Yunnan Copper is China's fourth-largest copper producer by output and a unit of Aluminum Corp. of China.