The CBA-owned ASB reported before-tax earnings of $947 million in the period, up 17% on the $814 million reported in the previous corresponding period (pcp).
Total income rose 8% to $1.73 billion from $1.61 billion and the reported profit grew by 21% to $685 million from $568 million in the pcp.
Contributing to this financial year's result was an increase in after-tax fair value gains on other derivatives of $51 million.
Excluding that, the reported profit would be up 11% to $658 million.
The bank reported a net interest margin of 2.16% in the period, up from 2.01% last year, 1.68% in 2010, 1.63% in 2009 and 1.83% in 2008.
Bank chief executive Barbara Chapman said ASB's performance reflected the ongoing focus of staff in providing unbeatable service combined with innovative, simple solutions for customers.
That was highlighted with the recent launch of the ASB mobile app which allowed customers to make payments using mobile numbers, email addresses and by using Facebook contact details.
"Also underpinning ASB's performance was an increase in operating income, partly as a result of the trend of customers shifting from fixed to floating rate home loans - although this trend has subsided in recent months."
Impairment losses on advances totalled $47 million, 35% down on the pcp expense of $72 million.
The reduced losses reflected the non-recurrence of the Christchurch earthquake provision recorded in the previous year, with arrears and hardship levels in Christchurch improving, Ms Chapman said.
During the period, ASB's business lending grew 6%, with most growth coming in the second half of the year.
Rural business lending also increased in the year with the bank securing its largest share of "June 1" farm settlements.
As a result, the bank saw an increase in its total share of the rural lending market in the month of June, she said.
Parent CBA reported a profit of $A7.1 billion ($NZ9.25 billion), up 11% on the pcp, but said revenue growth was subdued as customers remained cautious about the global environment.
Cash profit for the year at Australia's largest bank by market value - a measure that strips out one-off costs and is more closely watched by investors - rose 4% to $A7.11 billion.
Chief executive Ian Narev said it was "good result given the uncertain environment in which we are operating".
