LONDON: Copper prices slid to a six-year low as worries about economic and demand growth in top consumer China escalated and abundant supplies reinforced expectations of surpluses.

Benchmark copper on the London Metal Exchange earlier hit $4,787.50 a ton.

The metal used in power and construction was down 0.3 percent at $4,810 at 1207 GMT.

It is down nearly four percent so far this week, and heading for its largest loss since September.

Data earlier this week showed China’s industrial output was at a seven-month low in October and investment slipped to its weakest pace since 2000.

“We’re seeing short selling largely on the back of negative news flow out of China where the economy is still not showing signs of stabilizing,” said Societe Generale analyst Robin Bhar.

“We’ve not had enough production cutbacks to rebalance the market, so a further fall in the price should act as a necessary incentive in an oversupplied market to force more output cuts.”

Some producers have cut output and others are planning to cut, but analysts say more will be needed before participants start to believe a more balanced market is in sight.

The consensus for the copper market surplus this year is 349,000 tons and 177,000 tons for 2016, according to a recent survey.

“We could see even lower levels if momentum picks up again, maybe $4,710 (July 2009 low)” a trader said.

“The catalyst could come from the dollar later today.”

A higher US currency makes dollar-denominated commodities more expensive for holders of other currencies.

Three-month aluminum was up 0.2 percent at $1,495 a ton after Russian aluminum giant Rusal said it would consider cutting 200,000 tons of annual aluminum output over the next six to nine months.

But the trader was skeptical. “They’ve been saying that sort of thing for months.”

Zinc holding near six-year lows, was down 0.1 percent at $1,614 a ton.

Bearish sentiment can be seen in an LME report showing funds holding the largest short position since the exchange started compiling the report.

“We estimate global discretionary zinc concentrate and metal inventories at over 3 million tons or about 80 days of consumption,” Citi said in a note.

“This is a worryingly high level which the market would need to work through to cause tightness in the refined zinc market.”

Lead lost 0.7 percent to $1,606 a ton, tin gained 0.7 percent to $14,725 and nickel fell 0.4 percent to $9,375.