Copper prices have recovered from two-week lows on news that as Chinese imports of the metal rose in August, but worries about an over supplied market and a stronger US dollar have tempered gains.
Benchmark copper on the London Metal Exchange closed up 0.3 per cent at $US5,269 a tonne, after earlier hitting a low of $US5,208.
A rise in China's copper imports, up 12 per cent year-on-year at 262,691 tonnes in August, suggested industrial activity could pick up in the fourth quarter.
But some analysts are not yet convinced.
"The market has too much metal lying around, not enough is being consumed, and until that changes, it's difficult to see why prices shouldn't just be bumping along the bottom," Societe Generale analyst Robin Bhar said.
The stronger US dollar could cap gains, however, by making dollar-denominated commodities more expensive for non-US firms.
Traders looking for new Chinese fiscal stimulus to finance infrastructure projects are more optimistic for copper's demand and price prospects.
Short position covering and hedge funds and money managers switching to a net long copper position on COMEX from a net short are also expected to help copper.
The net long on COMEX suggests some are trying to "guess" the bottom of the price cycle, consultants Kingdom Futures said in a note.
"The timing could be too early by some margin but that is not to discount the possibility of several 'false starts' before the market truly turns around."
Three-month aluminium ended down 0.5 per cent at $US1,616 a tonne from $US1,624. Analysts expect any gains to be brief with Chinese production and exports rampant.
Zinc was down 1.8 per cent at $US1,657 a tonne while lead gained 0.7 per cent at $US1,706.
Destocking in China and higher Chinese exports are expected to keep prices of lead under pressure.
"Chinese demand has weakened on a slowdown of e-bike sales," Bank of America Merrill Lynch said in a note. Electric bicycles, or e-bikes, use lead-acid batteries.
Tin was little changed at $US15,145 a tonne from $US15,150, but higher shipments from top exporter Indonesia mean lower prices to come, traders said.
Nickel rose 1.6 per cent to $US9,860 a tonne after data showed China's August refined nickel imports jumped 114.9 per cent to 20,615 tonnes.