Most Shanghai copper futures contracts ended up on Thursday despite paring gains, lifting London Metal Exchange prices from their kerb close levels, traders said.
The most active contract, October, closed 110 yuan higher to end at 24,960 yuan ($3,016) a tonne.
Most other contracts climbed between 40 and 320 yuan, while nearby July and August futures fell 30 yuan on market talk that China might have unloaded more copper from state reserves, traders said.
Backwardation in the Shanghai copper market has narrowed over the past few sessions as the speculation began to weigh on nearby contracts, they said. Combined volume increased to 186,748 lots, up from Wednesday's slack 172,864.
"In the absence of any fresh news, the market looks to be stuck in wait-and-see mode," said a Shanghai trader.
"Trade has not been active so these moves cannot be taken as indications as to where the market is headed," he added.
The London Metal Exchange three-month copper contract traded at $2,586/$2,596 a tonne on Thursday's Asian trade, up from London's on Wednesday kerb close of $2,580 after losing $22 on the day.
Spot copper in Shanghai dipped in line with nearby contracts to move in a range of 25,980-26,200 yuan per tonne on Thursday.
Shanghai aluminium contracts ended mixed on Thursday, closing between 80 yuan lower and 300 yuan higher.
Volume fell to 38,694 lots from Wednesday's 58,090 lots. LME three-month aluminium was trading at $1,673/$1,676 a tonne in Asian trade on Thursday, versus London's kerb close of $1,678 on Wednesday after gaining $29.