Shanghai copper closed down on Wednesday, defying an overnight rise on the London Metal Exchange (LME), as prices came under pressure from increased copper stocks due to arrive later this month, traders said.
The most active October contract closed 430 yuan lower at 27,650 yuan ($3,340) a tonne, while most other contracts fell between 220 yuan and 460 yuan.
Volume rose to massive 268,694 lots from meagre 40,820 lots on Tuesday. "The availability of copper stocks here has been on the increase since March, and we're seeing the impact now," said a trader in Shanghai.
The LME copper contract was quoted at $2,915/$2,920 a tonne in Asia on Wednesday versus on Tuesday's London kerb close of $2,920.
It lost $96 on the day at the beginning of the week, but recouped $40 in cautious trade on Tuesday. Spot copper fell 200 yuan to move in a range of 27,620 yuan to 27,700 yuan per tonne, in line with futures.
Most Shanghai aluminium futures closed up between 10 and 70 yuan on Wednesday, with volume decreasing to 144,462 lots from Tuesday's hefty 245,328 lots.