Shares traded marginally lower at lunchtime, erasing early gains, with banks unable to hold onto a morning advance.
The S&P/ASX 200 index lost 3 points, or 0.1 per cent, to 5946 while the All Ordinaries slipped 2 points to 6052. The Australian dollar edged up 0.1 per cent to US77.19¢.
The banks traded flat-to-lower, with CBA steady, ANZ down 0.2 per cent, NAB down 0.6 per cent and Westpac lower by 0.1 per cent as the sector came under renewed scrutiny on another day of royal commission hearings.
Supermarkets were lower as well, with Wesfarmers giving up a portion of Friday's Coles demerger-related gains to trade down 1.8 per cent and Woolworths down 0.8 per cent.
Cochlear lost 1.8 per cent as it started trading without rights to its latest dividend payout.
Miners were making some headway, however, with BHP up 0.7 per cent, Rio Tinto up 0.9 per cent and South32 up 0.9 per cent.
Energy firms were also strong, with Woodside up 1.7 per cent, Santos up 1.6 per cent and Oil Search up 1.5 per cent.
Brent crude traded down 17¢ at $66.04 as traders paused after a 1.7 per cent rally for the commodity in US trading on Friday.