BHP met its revised target for iron ore production, but flagged $1 billion (£806 million) in productivity losses for fiscal 2019 in its quarterly production report, flowing from disruptions to operations across its commodities.
The Anglo-Australian miner's iron ore output fell to 71 million tonnes during the fourth-quarter ended June 30, compared with 72 million tonnes a year earlier. The figure was below a UBS estimate of 72.6 million tonnes, but up 12 percent on the March quarter.
Production across its suite of commodities broadly recovered from March, which is typically the weakest quarter due to Australian weather conditions.
"Generally speaking, it's just a little bit softer than we expected, although it's strong sequentially," said analyst Glyn Lawcock at UBS in Sydney.
"If you look at their guidance it's highlighting that they aren't really growing their volumes, so that means price is key going into next year."
Miners have benefited from iron ore prices at five-year highs, after a dam disaster in Brazil led to a global shortage of the steel-making ingredient. Analysts expect some of the windfall profits to be passed on to shareholders when Australian miners report their profits next month.
BHP forecast iron ore production at 273 million to 286 million tonnes for the 2020 fiscal year, a 1%-6% increase from 2019 production of 270 million tonnes, which was slightly down from 275 million tonnes for 2018.
The iron ore shortage was exacerbated after Cyclone Veronica tore down the coast of Western Australia in March, hitting several iron ore export hubs, in a return of more turbulent weather after several moderate years.
BHP was on track with its growth projects, Lawcock noted, after Rio Tinto flagged a cost blow out at its key growth copper project in Mongolia when it reported on Tuesday.
The $1 billion in productivity losses followed flooding in Australia's Queensland state that hit BHP's metallurgical coal operations, as well as changes to its Nickel West mine plan and higher costs in thermal coal, it said.
That added to disruptions mostly at its Australian operations in the first half that included an acid plant outage Olympic Dam, a fire at its Kalgoorlie nickel smelter, and a train derailment.
The figure did not include disruptions from Cyclone Veronica BHP said.
In other metals BHP forecast around a 9-4 percent decline in petroleum production and growth of 1-8 percent in copper over the next financial year. It forecast a decline in energy coal output.
(Reporting by Melanie Burton in Melbourne; additional reporting by Ambar Warrick and Rushil Dutta in Bengaluru; Editing by Bernard Orr and Richard Pullin)
By Melanie Burton