Australian shares fall as Westpac leads banks into red

Westpac tumbled more than five per cent after it noted third-quarter mortgage applications had slumped by a fifth since May's federal budget announcement, raising concerns about how banks will fare this earnings seasons.

Miners offered a ballast to the financial sector weakness, as gold and lithium prices advanced, while BHP and Rio also made gains despite copper prices easing on Friday.

The Australian dollar is buying 70.69 US cents, up from 70.33 US cents on Friday at 5pm AEST, the Aussie holding at multi-week highs before the Reserve Bank's interest rate decision on Tuesday.