The Australian Bureau of Statistics said the surplus widened slightly during the month, with the balance on goods and services at a seasonally-adjusted Aus$1.826 billion (US$1.894 billion).

This was lower than analysts' expectations of Aus$1.9 billion and compares with a downwardly-revised surplus of $1.817 billion in June.

Trade Minister Craig Emerson said Australia's engagement with Asia underpinned what he called a "solid performance" in July.

Exports to East Asia have surged during the past 12 months, with shipments to China up 35 percent, South Korea up 27 percent and Japan up 23 percent, he said.

"Australia's export success with Asia hasn't been the result of good luck but of good management over the last quarter-century," said Emerson, adding that exports continued to do well despite tough economic times.

"An uncertain global economic climate, together with the strong Australian dollar, present formidable challenges for Australian exporters," he said.

"On the whole our exporters are succeeding despite having to bear these burdens."

During July, exports were down 1.0 percent in adjusted terms to Aus$26.1 billion with the month-on-month fall driven mainly by a 12 percent decline in coal shipments and a 19 percent fall in "other mineral fuels".

Manufactured exports rose six percent while metals -- excluding gold -- gained 18 percent.

Other major manufacturing export categories were steady, and rural exports fell one percent.

Imports dropped 1.0 percent to Aus$24.6 billion, with non-industrial transport equipment, up 18 percent, a main contributor, partly offset by a nine percent fall in textiles, clothing and footwear.