NAB talks about raising rates

National Australia Bank chief executive Cameron Clyne has hinted that the bank may raise interest rates on mortgages outside of normal interest rate changes by the Reserve Bank.

"The reality is we're facing a structural shift in the funding profile of the bank. Average costs are going up and we're just going to have to monitor that," he said.

NAB reported lower cash earnings for the half year to December 2008 and a profit result of more than $2 billion for the six months, down from $2.24 billion last year.