SYDNEY, AAP – Australian shares edged higher by noon, with investors staying in cautious mode over the fallout of the Ukraine conflict after Western nations imposed fresh sanctions on Russia.

By 1200 AEDT on Monday, the benchmark S&P/ASX200 index was up 19.7 points, or 0.28 per cent, to 7017.5 points.

The All Ordinaries index rose 13.7 points, or 0.19 per cent, to 7287.3 points.

Russian President Vladimir Putin put the country’s nuclear deterrent on high alert on Sunday after Western nations announced a harsh set of sanctions including blocking certain Russian banks’ access to the SWIFT international payment system.

That particularly weighed on financial stocks in the local market, while defensive sectors like healthcare and property trusts were also affected.

Three of the Big Four banks were trading in the red, with only Westpac up 0.1 per cent by midday.

Suncorp shares were down more than 3 per cent to $10.75 after the insurer said it expected the heavy rainfall and floods in Queensland and NSW to cost it about $75 million after receiving more than 5,000 claims.

Healthcare stocks were also trading lower, led by a 1.5 per cent decline in biotech giant CSL.

However, heavyweight mining and energy stocks were higher, limiting the damage.

Local energy shares rose after oil prices jumped more than $US7 a barrel on fears of supply disruption following the new sanctions on Russia. Santos and Woodside Petroleum were both trading more than 2.0 per cent higher.

Miners also followed suit, with BHP climbing 3.0 per cent to $46.20 and Rio Tinto up 2.5 per cent to $117.55.

In corporate activity, buy-now-pay-later operator Zip Co agreed to buy US-focused Sezzle in a deal worth $491 million, as it looks to expand its reach in the key US retail market to take on rivals such as Afterpay.

Shares in both Zip and Sezzle were in a trading halt.

Meanwhile, the Australian dollar was lower at 71.84 US cents at 1200 AEDT, compared to 71.97 US cents at Friday’s close.