The unexpected drop in China's exports and imports – a decline of 0.7% versus expectations of an 8% rise – sent shudders through the resources sector. But buried within the data however was a 10% year on year surge in the country's copper imports.

Shipments to China of refined metal, alloy and products were 379,951 tonnes in June the highest since September. China consumes some 42% of the world's copper.

Daniel Briesemann, an analyst at Commerzbank AG in Frankfurt, said in a report imports could continue to be relatively robust in the coming months too and that "the trade statistics for the economy as a whole are probably to blame for the fact that the copper price is not profiting significantly from these figures."

China's traders have been trading "opportunistically" says Commerzbank to make the most of softer prices and also making the most of arbitrage opportunities as London Metal Exchange prices decline to as much as $75 below the Shanghai price.

Copper for delivery in September climbed 0.8% to $3.09 a pound by in New York on Wednesday, up from near three-year lows of $3.03 reached on Tuesday. London Metal Exchange copper for delivery in three months rose $50 to $6,780 a tonne.