Labor contract talks are underway at Peru's polymetallic mineral producer Compania Minera Antamina SA, a company official said Tuesday.

The workers' contract with the company expired July 24.

"Talks are going well," Gonzalo Quijandria, corporate affairs manager at the company, told Dow Jones Newswires.

He said the company is meeting with the union this week but did not give a date for when the new agreement could be reached.

In the first half of this year, Antamina produced 223,718 tons of zinc and 171,404 tons of copper, according to Peru's energy and mining ministry.

The mine in Peru's central highlands is a joint venture of BHP Billiton Ltd., (BHP) with a 33.75% stake; Xstrata PLC (XTA.LN), with another 33.75%; Teck Resources Ltd. (TCK) with 22.5% and Mitsubishi Corp. (MISBHY) with 10%.

-By Leslie Josephs, Dow Jones Newswires; 511-98853-8610; peru@dowjones.com