Rio Tinto (LON:RIO) and Anglo American (LON:AAL) ticked higher despite mixed updates from both mining giants.
Broker Investec said Rio was below expectations in all areas except coking coal, though iron ore production saw the major shortfall.
The miner has been piling on the production tonnes at its Pilbara operations in Western Australia, which in part has helped to hammer the price of the bulk commodity down to US$50 per tonne.
There was some minor respite for smaller rivals as Rio lowered its production guidance for the full year to 340mt from 350Mt, but it will still mean an extra 32Mt coming on stream over the remainder of the year.
Production in the quarter to June was affected by severe weather in the Pilbara region, Rio said, though output was still 9% higher than a year earlier at 79.7mln tonnes and 7% above the previous quarter.
Rio also lowered guidance for titanium dioxide and uranium output.
Anglo American (LON:AAL) meanwhile indicated it would take an impairment of between US$3-4bn for the Minas Rio iron ore mine in Brazil and some Australian coal assets.
Diamond production fell 6% year-on-year to 8mcts with De Beers trimming production for weaker market conditions.
Investec said Anglo’s decision to adjust output in a tough diamond market was encouraging.
Shares in Rio were 38.5p higher at 2,635.5p while Anglo added 16.7p to 891.1p.
Charles Stanley was sceptical towards Anglo, saying its bosses had yet to fully achieve high targets and would not generate net cash, excluding disposals, until 2016 or later.
Anglo was too exposed to South Africa, where restructuring was politically difficult, strikes were increasingly likely and wage inflation and demands were high, the broker said.
Stanley's Tom Gidley-Kitchin wrote in a note: "H1 production was overall in line, although on an annualised basis towards the lower end of full year guidance and this may be revised down in a couple of divisions.
"There will be (yet) another impairment charge of $3-$4bn after tax with the H1 results, to no one’s surprise, reflecting the impact of lower commodity prices on asset values. We maintain a 'reduce' recommendation."