Peru's polymetallic mineral producer Compania Minera Antamina SA has still not reached an agreement for a new labor contract with its employees, a company official said Tuesday.

The workers' contract with the company expired July 24.

"This is going to take a few weeks," Jose Salazar, told Dow Jones Newswires.

He said it was not clear 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