Iron ore and petroleum increasingly dominate BHP Billiton's production as the world's biggest miner posted record iron ore shipments.
However, volumes for base metals fell, driven down partly by industrial action at its Escondida mine in Chile.
Western Australian iron ore shipments rose to a record annualised rate of 173 million tonnes per annum in the September quarter, 28per cent higher than the previous corresponding period.
China's demand for the steelmaking commodity drove up iron ore production to 39.6 million tonnes in the three months to September 30, up 24per cent on the same period last year.
Western Australia shipments - where most of the iron comes from - had benefited from the duplication of BHP Billiton's railway lines, which had increased system capability, the company said in a statement.
First quarter petroleum production - natural gas and oil - was 51.4 million barrels of oil equivalent (boe), up 19per cent from last year.
That was driven by the $US15.1billion acquisition of the Fayetteville and Petrohawk shale businesses in the US.
Iron ore and petroleum represented 61per cent of the group's underlying earnings of $US32billion ($A31.27billion) for the past financial year, with that share set to rise this year.
The result was widely regarded as a strong one, but came amid reports that Chinese economic growth was at two-year lows and China had pressured the world's biggest iron ore producer Vale to agree to 10per cent price cuts. Iron ore prices hit record levels of about $US180 a tonne this year, compared to about $50 a decade ago.
City Index chief market analyst Peter Esho said iron ore prices still had the potential to fall a long way, which would be a drag on BHP Billiton's earnings.
''This is a great number, a great business, but it's not as widespread as some would believe,'' he said.
''It's still very heavily skewed towards iron ore and petroleum, if there's large movements in pricing of those two segments, then you're going to get that flowing through to BHP's share price.
''A lot of people say to us: BHP have record production across many divisions, its so large, its numbers look so good, why is it [share price] only up this much, why isn't the market pleased?
''The market is very wary of the earnings composition and exposure to iron ore and energy prices.''
The company's shares were underperforming in the market yesterday, falling 5c, or 0.14per cent, to $36.35.
