The Australian currency continued to fall against the greenback after the Reserve Bank of Australia (RBA) decided to leave its cash rate steady at its Oct 5 board meeting.

The RBA surprised the market on Tuesday by keeping the official cash rate at 4.5 per cent for the fifth straight month. Analysts and economists had expected an increase of 25 basis points given the nation's solid trade surplus, a 20-month high in job advertisements and unemployment level of just 5.1 per cent.

At 1440 AEST, the local unit was changing hands at 95.72 US cents, down from 96.70 US cents just prior to the announcement at 1430 AEST.

At midday, the Aussie was buying at 96.72 US cents, down from Monday's finish of 96.95 cents. It reached a two year high 97.5 cents late last week.

Since 7am, the local unit traded between 97.37 US cents and 96.55 cents.

Analysts said the Aussie was weighed down by a weak share market. A poor morning on the local bourse sapped momentum form the domestic dollar, according to Nomura Australia chief economist Stephen Roberts.

''It's a touch lower after the softness running through equity markets overnight and in our markets today," he said.