Copper hit a one-week high on Friday, boosted by improving demand expectations and positive US housing data, but concerns about monetary tightening in China, the world's largest consumer of the metal, capped gains. Copper for three-months delivery on the London Metal Exchange closed at $6,270 a tonne versus $6,049 on Thursday.
Earlier, the metal used in power and construction rose more than 3 percent to $6,285 a tonne, its highest since August 14. An industry survey showed on Friday sales of previously owned US homes in July notched their fastest pace in nearly two years, boosting economic sentiment. "This is all very constructive because the market needs to see data not coming in-line or barely beating estimates," said Edward Meir, an analyst at MF Global.
"People are pushing prices higher because of what they perceive to be a pick-up in demand - the question is how strong that will be." Copper prices have doubled this year, as China ramps up imports to record levels, and the trickle of macro data begins to improve, sparking hopes for an economic recovery.
"The PMIs, a slightly weaker US dollar and of course the firmer stock markets which signal economic recovery is a supportive factor ... but with improving prices there is also the risk that companies re-open mines," said Peter Fertig, an analyst at Quantitative Commodity Research. Workers at Chile's Spence copper mine have demanded a 5.5 percent wage hike, marking the start of potentially tough collective contract negotiations.
Among other industrial metals, aluminium ended at $1,930 a tonne from $1,906. Earlier the metal used in transport and packaging hit $1,872, its lowest since late July. Global daily average primary aluminium output excluding China fell in July to 63,100 tonnes, but Chinese production rose to 1.088 million tonnes, data showed on Thursday.
"We believe China's aluminium production is ramping up again. In addition, China's stockpiles of aluminium are significant," Citigroup Global Markets said in a note. It added Chinese aluminium imports should fall in the coming months as the Shanghai-London arbitrage has closed. Zinc closed at $1,834 from $1,804, battery material lead was at $1,863 from $1,820, while tin was last bid at $14,300 from $13,800. Nickel closed at $19,300 from $18,875. Jinchuan Group Ltd, China's largest nickel producer, lowered its nickel prices by nearly 5 percent.