The 43-day strike at Escondida copper mine - the longest private-sector mining strike in Chile's history - ended on March 24, but part owner and operator BHP only lifted the force majeure on Thursday.
Escondida is the world's largest copper mine by a large margin and the operation accounts for about 5% of the world's total copper output. Estimates put lost copper output during the strike at around 120,000 tonnes.
Reuters reports that the labour action cost BHP roughly $1 billion in lost revenue:
"I'm pleased to say that our copper FM (force majeure) is lifted as of today. We are back to normal," BHP's chief commercial officer, Arnoud Balhuizen told reporters after addressing a mining luncheon.
Force majeure remained in place on shipments from its coal mines in Australia's Queensland state, where a cyclone in late March knocked out rail haul lines, Balhuizen said.
It's not the end of labour problems for BHP at Escondida. The strike ended without a new deal being signed and the 2,500 member union invoked a rarely used legal provision, known as Article 369, which allows them to extend their old contract for 18 months. At the end of that period, both sides would again need to try to reach a new agreement.
Melbourne-based BHP owns 57.5% of the iconic mine, Australian peer Rio Tinto holds 30% and Japanese firms the remainder.
The longest strike in Chile was the 74-day stoppage at Codelco's El Teniente mine in 1973, which took place shortly before the military coup that overthrew socialist President Salvador Allende.
Chile is the world's biggest copper producer accounting for around 30% of global output, and sales of the metal make up about 60% its export earnings.
Comex Copper futures were last trading at $2.59 a pound in New York, up 21% from this time last year.