China is turning more to Australia than Brazil for cheaper iron ore, threatening to take business away from the popular transatlantic route, experts said.

Commodity volume for 58% ore from Australia to China, priced at $69 per tonne, hit a new high of 18.7m tonnes last week, according to Clarksons Platou Securities.

At the same time, Brazilian exports for 62% ore at $84 per tonne fell 22% from the prior week to 5m tonnes amid inspections of Brazilian iron-ore giant Vale's mines and dams.