Anglo American PLC (LON:AAL) reduced diamond production in the first quarter, but its iron ore operation in Brazil nearly trebled output.
The miner’s diamond production fell 10% to 6.9 million carats in the period following a decision to cut output due to tough markets in 2015.
But the company said rough diamond sales in early 2016 reflected improved trading compared to the second half of last year.
Iron ore production from the Kumba mine in South Africa decreased 27% to 8.9 million tonnes as Sishen was transitioned to a lower cost pit.
But ore output from Minas-Rio in Brazil increased to 3.3 million tonnes as the operation continued to ramp up, rising 3% versus the fourth quarter of 2015.
Platinum production increased 4% to 567,000 ounces due mainly to higher production from Amandelbult, Mogalakwena and Unki, partially offset by lower production at Rustenburg.
Chief executive Mark Cutifani said: “The Q1 2016 operating results are in line with the equivalent period of 2015 on a copper equivalent basis and reflect the major restructuring programme under way and our ongoing efficiency and cost reduction strategy.
“They also demonstrate the market discipline we continue to show in our key markets, particularly diamonds and platinum, and are consistent with our restructuring plans as we focus on lower cost and higher margin assets.
“We are encouraged the actions we have taken in diamonds are continuing to have a positive effect, while operational productivity continues on an upward trajectory.
"As a consequence of our solid progress, our production guidance for 2016 remains unchanged.”