Global mining giant BHP Billiton on Wednesday said iron ore production fell eight percent in the March quarter from the previous three months due to Australian cyclone activity.
But the world's biggest miner said the 37.9 million tonnes produced was still 14 per cent better than the March quarter of 2011.
Cyclones temporarily closed ports along the Pilbara coast of Western Australia early this year, a setback that also hampered Rio Tinto, which posted lower-than-expected quarterly iron production from the region on Tuesday.
Both BHP and Rio are investing billions of dollars in beefing up mining capacity of the steelmaking commodity in the Pilbara, betting heavily on continued demand from China and elsewhere.
The Melbourne-based BHP added that output of metallurgical coal, another steelmaking ingredient, was down 14 percent on the December quarter rates but rose 10 percent from the same period last year.
Wet weather constrained coal production in the three months to March, as well as an ongoing industrial dispute at seven mines jointly owned with Japan's Mitsubishi Corp.
The company's recently acquired US oil business, however, contributed to strong growth in petroleum product production, up 58 per cent compared to the same period last year, but down three percent on the prior quarter.