The lender on Thursday said cash earnings had slumped 9.8% to $5.18 billion - a fall of $563 million - in the year to September, in line with guidance provided earlier this month.
Provisions relating to a misconduct over insurance policies in the Clydesdale and Yorkshire bank were a key reason for the decline.
Andrew Thorburn, chief executive of NAB, said:
"In relation to exiting UK banking this means we are now examining a broader range of options including those provided by public markets.
"We have an intention to exit the UK, we think there's an opportunity now that probably wasn't there before. What we are signalling is that's our intent, it is an absolute priority."
As a consequence of Clydesdale and Yorkshire's involvement in payment protection insurance and interest rate swap mis-selling, NAB warned that its profits would be lower than expected.
The Australians revealed a £420m provision for PPI and £250m for interest-rate swap mis-selling for Clydesdale and Yorkshire in the financial year.
NAB paid £420m for the Clydesdale Bank in 1987 and £900m for the Yorkshire Bank in 1990.
Together, Clydesdale Bank and Yorkshire Bank have more than 320 branches. Earlier this year NAB announced a plan to close around 30 branches and invest £45m in its UK business.
An investment analyst at Watermark Funds Management, Omkar Joshi, said the profit result was about 1% below market expectations, but all of the attention was on Mr Thorburn's strategy for improving NAB's future performance.
Mr Joshi said:
"Revenues in the second half were 1% lower than the first half which suggests that the operating trends in the business still remain challenging."
"However, the key focus is now on the new strategy that management is embarking on in refocusing the business on its core domestic franchises."
