Nickel slid to the lowest since May 2009 as Greece’s debt crisis undermined confidence in the global growth outlook and threatened commodities demand.

The London Metal Exchange’s Index of six industrial metals is heading for a fourth straight quarterly loss, the longest streak since 2001. Greece’s standoff with its creditors is adding to economic concerns amid a slowdown in China. Europe is forecast to account for almost one-fifth of the world’s nickel demand this year, Morgan Stanley estimates.

“People are worried that this crisis may spiral out of control, and global growth may be impacted,” Bart Melek, the head of commodity strategy at TD Securities in Toronto, said in a telephone interview. “Traders and investors are focused on the developments in Europe.”

Nickel for three-month delivery retreated 4.9 percent to settle at $11,835 a metric ton at 5:51 p.m. in London, the biggest drop since Sept. 9. The price touched $11,730, the lowest since May 2009. The metal has lost 22 percent this year.

Stockpiles tracked by the LME rose 0.2 percent to 459,018 tons, the first increase in three days. China is the world’s biggest metals consumer.

Aluminum for delivery in three months fell 0.2 percent to $1,701 a ton on the LME. A close at $1,685.60 would leave prices down 20 percent from the closing high on Sept. 2, meeting the common definition of a bear market.

Also in London, tin and zinc declined, while copper and lead rose.

On the Comex in New York, copper futures for September delivery dropped 0.1 percent to $2.6335 a pound.