Chile’s copper output tumbled 8.5 per cent to 426,477 tonnes in June after a contract workers’ strike, heavy rains and power outages hit operations at the world’s top copper producer, the government said.

The sharp output drop in Chile highlights the supply side challenges that have kept global copper prices near record highs despite fears over the health of the world’s economy.

Copper production in Chile is set for another big drop in July after a string of strikes at some of the world’s top mines and a harsh winter storm that halted operations across the country’s mining heartland.

A workers strike at the world’s largest copper mine, Escondida, marked one week on Thursday with no signs of a near resolution to a benefits conflict that has threatened to spread to other mines in Chile.

Chile produced 426,477 tonnes of copper in June after heavy rain and snow halted output at Escondida for two days and a violent protest by contractors at Codelco’s El Teniente mine curbed output there.