Iron ore shipments to China from Australia's Port Hedland terminal, the world's biggest iron ore port, fell more than 5% in September from a month earlier, port data showed on Tuesday.
Shipments to China totalled 36.05 million tonnes in September, down from 38.14 million tonnes in August, the Pilbara Ports Authority said.
Overall iron ore shipments totalled 41.97 million tonnes in September, down more 7% from 45.43 million tonnes in August.
Port Hedland is used by three of Australia's top four iron ore miners: BHP Group, Fortescue Metals Group and Gina Rinehart's Roy Hill.
Reporting by Colin Packham