Oct. 12 (Bloomberg) –Copper fell the most in a week on concern that metal demand will slide as the global economy falters, Chinese exports wane and Europe's debt woes escalate.

Chinese export growth probably declined to 20.5 percent in September from 24.5 percent a month earlier, according to economists' estimates compiled by Bloomberg. European Central Bank President Jean-Claude Trichet said the debt crisis threatens the financial system.

"China's economy is contracting, and we are not seeing any greater demand there," Frank Lesh, a trader at FuturePath Trading in Chicago, said in a telephone interview. "Europe has real troubles that will drag on the world economy, and it will remain a concern for the next year at least."

Copper futures for December delivery fell 2.3 percent to close at $3.2905 a pound at 1:15 p.m. on the Comex in New York, the biggest drop for a most-active contract since Sept. 30.

In the third quarter, copper tumbled 26 percent, the most since 2008. The metal touched a 14-month low of $2.994 on Oct. 3.

"With respect to China, not only are there growing concerns about growth prospects, but renewed attention is being placed on the state of Chinese banks and the billions of dollars of nonperforming loans they are carrying," Edward Meir, a senior commodity analyst at MF Global Holdings Ltd. in Darien, Connecticut, said in a report.

On the London Metal Exchange, copper for delivery in three months fell 2.7 percent to $7,290 a metric ton ($3.31 a pound). Aluminum, zinc, tin, nickel and lead also declined.