Shanghai copper rose on Wednesday in tandem with pick-up in London prices as investors watched to see how a series of strike threats played out. The most-active September copper contract on the Shanghai Futures Exchange closed up 0.5 percent at 64,780 yuan ($8,504) a tonne.
"Copper prices are ranging, but I think they could fall rapidly in the next six weeks," a trader at a leading Chinese copper smelter said. "There is no buying from domestic fabricators when Shanghai prices move above 65,000 yuan," he said, adding that copper prices in London could drop to $6,000.
Copper for delivery in three months on the London Metal Exchange gained $60 to $7,490. Dealers said markets would tread water as they kept an eye on a series of threatened labour disputes, most notably at the world's largest copper miner, Chile's Codelco.
"People are waiting to see what happens at Codelco. If the contractors walk out, there could be a bit of a push up in prices," said Australia and New Zealand Bank analyst Andrew Harrington. Workers at Chile's Collahuasi, one of the world's largest copper mines, have set a strike vote for June 27, barring an improved wage offer from the company.
The 689-member union is demanding improved health and education benefits and a retroactive share of soaring company profits. At other Codelco operations, sub-contractors plan to meet on Thursday to give the final go-ahead to a strike across Codelco's five divisions.
Christian Crevasse, a spokesman for the umbrella group of Codelco's 30,000 subcontract workers, said the meetings would have the express purpose of ratifying the strike.
Managers at the Canadian Copper Refinery in Montreal are trying to ramp up production to around 35 percent of capacity after a strike resulted in force major at the plant which produced around 300,000 tonnes of copper last year.
The changes could temporarily stem a flood of exports, particularly of steel and aluminium products, that has helped widen China's trade surplus to $216.7 billion in the 12 months through May, and raised hackles in the United States and Europe.
The changes will take effect from July 1. LME aluminium was up $9 at $2,715 a tonne after a steady performance on Tuesday in contrast to most other metals. Shanghai September aluminium eased 10 yuan to 19,320 yuan a tonne at Wednesday's close.