UPDATE 1-Peru miners aim for strike decision on Thursday

(Recasts with union, government hopes for talks; details on individual mines)

By Hilary Burke

LIMA, May 3 (Reuters) - Peru's largest miners' union said it hoped to either reaffirm or call off its nationwide strike on Thursday, as talks with the government continued.

The National Federation of Metallurgic and Steel Miners called the indefinite walkout on Monday, demanding better job benefits and improved conditions for contract workers.

Three joint commissions created to address the miners' demands met on Thursday after lengthy talks were held a day earlier.

"We hope today (Thursday) we can define things, whether we decide to continue the strike, intensify it or see how it might end," Luis Castillo, the federation's leading official, told Reuters during an afternoon break in talks.

"We have to evaluate everything" discussed by the commissions, he added.

Union leaders from throughout the country were arriving in Peru's capital, Lima, to weigh the government's most recent proposals, federation official Jesus del Castillo said.

Nearly 300 workers were also marching to Congress to demand mining sector reforms, Del Castillo said.

"The dialogue is continuing throughout the day today. We believe we will finish sometime tonight, and we'll see if we can reach an agreement," said Jorge Villasante, a Labor Ministry negotiator.

Some mines have been affected by the indefinite strike, including two pits run by Southern Copper Corp. (SPC.LM) (PCU.N), one of the world's largest copper producers.

Workers at many of the country's other top mines have reported for duty as usual, however.

The Labor Ministry has said less than 5 percent of the mining sector's 120,000 workers joined the strike, while the union federation has estimated the number of protesting workers at 27,000 workers.

The umbrella group is made up of 74 unions representing about 22,000 workers.

Metals markets were watching the strike because Peru is among the world's top two silver producers and is the No. 3 copper and zinc miner as well as the No. 5 gold producer.

STRIKES TO GO ON?