(ShareCast News) - Copper futures jumped early on Wednesday morning amid news that talks between BHP Billiton and workers at its Escondida mine had broken down.According to reports, that opened the way for industrial action of indefinite length starting on 9 February.As of 1025 GMT three-month copper futures on the LME were rising to $5,888 a metric tonne, up from $5,809 during the previous session.BHP Billiton owned 57.5% of the deposit and Rio Tinto another 30.0%.Local reports cited a letter from the union to its workers, sent on 7 February, according to which "unfortunately this strike means the company will stop producing, bringing output almost to zero."The main sticking point in the negotiations was workers' demand that no distinction be made between new and existing staff.Miners at Escondida had asked for a 36-month contract including a 7.0% wage increase and a 25m peso 'end-of-conflict' bonus, whereas management had offered a 48-month contract, no salary increase and a 8m peso bonus.