Australia's trade surplus dropped by a third in October to $4.502 billion, from a downwardly revised $6.847 billion a month earlier.
Exports fell by a seasonally adjusted three per cent, according to the Australian Bureau of Statistics, dragged lower by declines in resources including metal ores and minerals; and coal, coke and briquettes.
Exports of non-monetary gold fell 25 per cent.
Imports remained steady.
The Australian dollar dropped about 0.3 per cent against the US dollar to as low at 68.33 US cents after the release of the data and news that retail spending had flatlined in the same month.