Peru’s largest miners’ union launched an indefinite strike Monday, but workers at several of the country’s largest pits were working as usual.

The National Federation of Metallurgic and Steel Miners called the strike to demand better job benefits and an end to outsourcing among mining companies.

Unionized workers at the Yanacocha gold mine, Latin America’s largest, said they would not participate in the walkout for now.

Miners at Antamina, the country’s largest copper producer, do not belong to the federation and have said they will not strike either.

Peru is among the world’s top two silver producers, and is No. 3 in copper and zinc and No. 5 in gold.

Four days of lengthy negotiations between the union and the labor ministry to reach an accord and avert the strike failed Sunday.

The federation is made up of 74 mining unions, representing 22,000 workers. About 110,000 miners are estimated to work in the sector overall.

Both the labor minister and leading mining companies predicted the strike would only be partial, without specifying how much metals production could fall as a result of the protest.

Mining is one of the South American country’s main economic drivers and accounts for more than half of export earnings.

The majority of Peru’s mines are controlled by large multinational companies, which have seen their profits surge on high metals prices. Workers’ demands for a greater share of those profits also have intensified.

The last nationwide strike took place three years ago, when miners stopped work for 48 hours to protest the previous government’s labor policies.

Copyright 2007 Reuters. All rights reserved.

Find More Other News : Company, Exploration, Mine Trade & Market, Mining Top News