A surge in exports of Brazilian iron ore to China drove up the spot rate for freight bound for Asia from South America to US$37 a tonne yesterday, 5.7 percent more than the day before, AgriCensus reports.

The rate for freight carried by Panamax ships sailing to Asia from Brazil and Argentina rose by 6 percent after exporters of iron ore booked several vessels, the agricultural news agency says.

In a separate report, the Freight Waves website quotes Star Bulk President Hamish Norton as saying greater production of steel in China is sucking in greater imports of iron ore.

China is also replenishing its stockpiles of iron ore, which were depleted when the Vale SA iron mine at Brucutu in Brazil was closed between January and June, Freight Waves quotes the ship manager as saying.