July 12 (Bloomberg) -- Copper prices fell in New York for the first session in six as workers at a mine in Chile were back on the job after an eight-day strike over wages.

The Zaldivar mine in northern Chile may be at full production this week, Rene Godoy, a union president, said today in a telephone interview from the city of Antofagasta. A strike at an Arizona mine owned by a unit of Grupo Mexico SA entered its 12th day.

``The market's being pressured because of Zaldivar settling their strike,'' said Marc Morgan, a trader at Triland USA Inc. in New York. That weighed more on the market than the strike at Grupo Mexico's Asarco unit, he said. Zaldivar's mine accounts for almost 1 percent of global output.

Copper futures for September delivery fell 2.2 cents, or 1.4 percent, to $1.539 a pound on the Comex division of the New York Mercantile Exchange. Prices gained 5.9 percent in the past five sessions. The metal has climbed 20 percent in the past year as global stockpiles dwindled to a 30-year low.

Zaldivar was set to produce 150,600 metric tons of copper this year, Placer Dome said on its Web site. Felipe Ruiz, a spokesman for the mine, last week estimated 2005 output at 144,000 tons.

Grupo Mexico said on July 4 that the strike may cut output at its Asarco unit by 50 percent. Asarco Chief Executive Daniel Tellechea and Asarco spokesman Genaro Guerrero didn't return calls for comment.

``I haven't heard from them, and they haven't heard from me,'' Terry Bonds, head of the United Steelworkers Union District 12 office in Albuquerque, New Mexico, said today in a telephone interview. Talks aren't currently scheduled with Asarco, he said.

In London, copper for delivery in three months fell $28, or 0.8 percent, to $3,338 a metric ton ($1.5138 a pound). Copper for July on the Shanghai Futures Exchange was little changed at 33,230 yuan ($4,015) a ton.

A futures contract is an obligation to buy or sell a commodity at a set price by a specific date.

To contact the reporter on this story: Jennifer Itzenson in New York at jitzenson@bloomberg.net.

Last Updated: July 12, 2005 14:10 EDT