"Operating conditions remain challenging," New Zealand-born chief executive Ralph Norris said.
"Whilst the Australian economy continues to perform relatively well, consumer and business confidence remains fragile, most noticeably reflected in subdued system credit growth."
Shares in Commonwealth Bank dropped 71c to A$49.15 on the ASX yesterday, ending two days of gains.
Westpac was steady, ANZ Banking Group rose 6c while National Australia Bank was little changed.
Westpac, Australia's second-largest lender, on November 2 posted a 13 per cent decline in second-half profit as lending growth slowed and debt market turmoil triggered a drop in earnings.
National Australia said last month that profit in the period rose 31 per cent as it won a bigger slice of the nation's mortgage market with discounted loans. ANZ Bank's profit rose 4.3 per cent, the lender said on November 3.
ANZ Bank, Westpac and Commonwealth Bank lowered their variable mortgage rates this month by the same amount as the central bank's reduction.
National Australia reduced its variable rate by 0.2 per cent.
Commonwealth Bank's Tier 1 capital ratio, a key measure of financial health, was 9.85 per cent as of September 30, it said yesterday.
The bank's total impairment expense was lower at 0.19 per cent of total average loans, or A$256 million in the quarter, the bank said.
- Bloomberg