Australia has posted a bigger than expected trade surplus, as mining exports continue to power ahead.

Official figures show the surplus eased by less than expected to $1.2 billion in February.

Imports rose by 1 per cent, driven by a jump in capital goods imports by businesses, while exports were driven by fuels such as liquefied natural gas and coal.

St George chief economist Besa Deda says Australia should expect more trade surpluses as resources companies ramp up their exports.

"The trade surplus in February represents the the fourth straight surplus that Australia has had," she observed.

"The rising capacity for resources production is clearly boosting export values, which rose 0.7 per cent in February, but are up 17 per cent on a year ago."