Top China copper producer Jiangxi Copper said on Thursday it has set up an emergency unit to deal with volatile markets and will tighten controls over futures positions, days after posting an investment loss that spooked investors.

The parent of Jiangxi Copper Co Ltd will also beef up supervision of its exposure to financial derivatives, the statement on its website said.

Foreign exchange and derivatives losses reported by several Chinese companies in recent days, including steel-to-property conglomerate CITIC Pacific , have further depressed already battered investor confidence and heightened concerns over companies' exposure to volatile financial markets.

Despite Jiangxi's statement that it would tighten internal controls, its Hong Kong-listed shares fell 8 percent to a two-year closing low of HK$3.83 on Thursday on concern over its bleak earnings outlook, weakening copper prices and investment losses.

But some market watchers said the damage could have been worse.