(Recasts with strike ends)

By Manuel Farias

SANTIAGO, May 5 (Reuters) - Chilean copper giant Codelco's subcontract miners on Monday agreed to end a 20-day, at times violent strike that helped push prices of the metal to new life highs, after voting to accept a government proposal.

Union leaders said their subcontractor members would resume work on Friday, lifting the latest in a series of strikes to demand a bigger share of copper windfall revenues and improved work conditions.

"We will return to work from the first shift tomorrow," union leader Cristian Cuevas told Reuters.

The subcontractors agreed to a proposal that they and Codelco say fulfill a series of agreements reached last year, among them a pledge by the state-owned giant to absorb some of them into its full-time ranks.

Subcontract miners at Codelco's Andina, Salvador, Codelco Norte and Ventanas divisions agreed to accept the proposal. Their colleagues at Codelco's giant Teniente division, home to the world's largest underground copper mine, voted against but agreed to go with a majority decision.

Earlier on Monday, Codelco said in a statement it was now running "at 80 percent" and was implementing a contingency plan at its Teniente division, home to the world's largest underground copper mine, allowing it to continue work at the deposit.

Codelco, the world's biggest copper miner, said last Tuesday it had lost about 19,000 tonnes of production, valued at about $100 million, but has given no updated output losses.