BHP Billiton reported record iron ore production for the second half of 2016, but the Anglo-Australian giant has lowered its copper targets because of pay disputes and power outages.
Production of iron ore increased four per cent to 118m tonnes in the half-year to December 2016 as the continued ramp-up of additional capacity at its Jimblebar mine helped push production of Western Australia Iron Ore to record levels.
Guidance for 2017 remains unchanged, between 228m and 237m tonnes, excluding production from its Samarco mine.
Copper production fell by seven per cent to 712,000 tonnes, sending production for the year down to 1.62m tonnes, two per cent below prior guidance. This reflects a reduction in volumes at its Olympic Dam.
Production didn't rise at any of BHP's copper mines, but Olympic Dam fell the most. Copper production there fell 30 per cent to 78,000 following a state-wide power outage that lasted nearly two weeks and was estimated to have cost the company AU$2.6m (£1.6m) per day.
Mike van Dulken, analyst at Accendo Markets, said pay disputes at its Escondida copper mine also pushed the cut, as the dispute could be replicated elsewhere in Chile, disrupting up to 14 per cent of global output.
"This compounds prior problems related to power outages in Australia and similar strikes at peer mines in Africa. All of which have contributed to rally the copper price form its lows."
Underlying attributable profit for the half year is expected to be in the range of $150m to $200m.
The miner's London-listed shares fell more than one per cent in afternoon trading, while its Australian-listed share price rose more than three per cent.
BHP Billiton chief executive Andrew Mackenzie said the company has performed well over a period of higher prices.
"Our simpler organisational structure has freed our assets to focus on what matters most and to deliver safer and more productive operations. Our consistent delivery of operating and capital productivity, and strict adherence to our capital allocation framework have positioned us to maximise shareholder value," Mackenzie said.