UPDATE: Chile Union Will 'Indefinitely' Extend Strike At Escondida

Jul 22, 2011 (Dow Jones Commodities News via Comtex) -- --Union votes to "indefinitely" extend strike at Escondida copper mine

--Minera Escondida to likely lose 3,000 metric tons of copper production every day workers are on strike

--Escondida is the world's largest copper mine

(Updates with more comments from union and additional details, starting in fourth paragraph.)

SANTIAGO (Dow Jones)--The largest union at Chile's Escondida copper mine voted to "indefinitely" extend a strike at the mine, which is controlled by global diversified miner BHP Billiton Ltd. (BHP, BHP.AU), union leader Jose Vidal said Friday.

Members of 2,350-strong Escondida Mine Workers Union No. 1 "unanimously voted" to extend the work stoppage, which began Thursday night and was initially slated to end 24 hours later at 8 p.m. EDT on Friday, Vidal told Dow Jones Newswires.

The unionized workers put down their tools at Escondida, the world's largest copper mine, over unmet contract demands, including an increase of their year-end bonuses.

After meeting with the labor-relations representatives from Minera Escondida, the company that runs the mine, and "not reaching a favorable agreement to our demands...workers decided to extend the strike indefinitely," the union said on its website shortly after voting was completed.

Company representatives declined to immediately comment on the matter.

Escondida, which produced 1.09 million metric tons of copper in 2010, stands to lose some 3,000 tons of copper output for every day workers are on strike.

The strike extension will likely boost already strong copper prices.

The most actively traded contract, for September delivery settled 0.6% higher Friday at $4.4100 a pound on the Comex division of the New York Mercantile Exchange.

The strike at Escondida comes on the heels of Chilean state copper company Corporacion Nacional del Cobre's first general strike in 18 years earlier this month.

Most of the 16,000 staff workers at Codelco, as the state-owned company is called, walked off their posts to protest restructuring and what they see as the first steps toward privatization.

The companywide strike at Codelco, which is the world's largest copper producer, left losses of $41 million on 4,900 metric tons of lost copper production.

BHP Billiton holds a controlling 57.5% stake in Minera Escondida, while Rio Tinto PLC (RIO, RIO.LN) holds 30%. The remaining 12.5% is held by a Japanese consortium led by Mitsubishi Corp. (MSBHY, 8058.TO).