South32 upgraded annual production guidance for its South African manganese operations and left guidance for all other minerals unchanged.
The company had a mixed output performance in the second quarter, with alumina, nickel, zinc, lead and silver production all falling.
Metallurgical coal production jumped after mining operations resumed in Australia, while manganese production also rose.
The company said that industry cost curves steepened during the December 2017 half year as a result of US dollar weakness, rising commodity prices and the environmental policy response in China.
At 9:24am: (LON:S32) South32 Limited share price was -1.2p at 224.8p