A closely-watched survey shows company owners remained pessimistic last month, as business conditions fell to a three-year low amid weak demand.
The NAB monthly business survey shows conditions were particularly tough for wholesalers, manufacturers and the construction sector.
That flowed through to sentiment with the confidence index dropping to a negative reading of minus-one.
NAB says confidence was lowest in the mining sector, despite activity at around average levels.
"You've basically seen in the last six months the mining sector going from by far the strongest confidence levels and by far the strongest activity levels to what you might call normal activity levels and the weakest confidence levels," NAB's chief economist Alan Oster said.
"This survey's not saying the mining boom's over by any stretch.
but what it's saying is people are very nervous about what it means." Mr Oster says the survey results are concerning.
He says the results show that indicators of future activity, like forward orders and capital expenditure, deteriorated in the month.
"It's basically showing an economy that's slowed significantly," he said.
"It'd be consistent with growth slowing to around the 2 per cent level." Mr Oster expects the Reserve Bank to cut the official interest rate again but not until February next year.
Meanwhile, the dollar fell after the survey was released at around 11:30am (AEDT) and was buying 104.1 US cents.