A deal to provide financial stimulus to the US economy has failed to help Australia’s share market from its slump, as investors appeared concerned by coronavirus outbreaks in Sydney and abroad.

The S&P/ASX200 benchmark index was down 27.2 points, or 0.40 per cent, to 6648.3 at 1200 AEDT on Monday.

The All Ordinaries had lost 28.5 points, or 0.41 per cent, to 6895.6.

US congressional leaders have reached agreement on a $US900 billion ($1.2 trillion) package to provide the first new aid in months to an economy hammered by the coronavirus pandemic.

The package would be the second-largest economic stimulus in US history, following a $US2.3 trillion aid bill passed in March.

The deal comes as the pandemic accelerates, infecting more than 214,000 people in the country each day. More than 317,000 Americans have already died.

Yet there was little lasting response on the ASX.

The ASX200 fell once trade began, then from 1020 AEDT rose to be about even, before falling again.

CMC Markets chief market strategist Michael McCarthy was surprised.

“I would’ve thought that would have given us a boost, but it doesn’t seem to be having an impact,” he said.

Instead all sectors were lower, after more coronavirus restrictions were imposed here and abroad.

In Sydney, the number of people infected by an outbreak has risen by 15 to 83.

Most state and territories have quarantine or isolation requirements on travellers from Sydney or NSW.

Several European countries have placed new restrictions on travel to and from the United Kingdom due to a new strain of the coronavirus spreading rapidly there.

The UK government tightened restrictions for 16 million people living in and around London.

On the ASX, property and energy were the worst sectors, down 1.26 and 1.24 per cent respectively.

Materials was the best sector, little changed after iron ore prices rose above $US160 per tonne.

BHP was down 0.12 per cent to $43.09, Fortescue was up 1.02 per cent to $23.14 and Rio Tinto was lower by 1.18 per cent to $116.14.

Fashion retailer City Chic was one of the best performers, up 16.08 per cent to $3.68, after it said it would buy UK womens clothing chain Evans for $41 million.

Evans, a plus-size retailer, has more than 100 stores across the UK as well as an online business.

The two businesses had a partnership for many years.

Health insurers were doing better after the federal government approved a rise in premiums.

The 2.74 per cent annual increase is due to take effect from April 1 next year.

Health Minister Greg Hunt says it is the lowest annual average premium increase in 20 years.

NIB rose 1.86 per cent to $5.72, while Medibank Private rose 1.36 per cent to $2.97.

In banking, the big four and Macquarie were all lower by less than one per cent.

The Aussie dollar was buying 75.92 US cents at 1200 AEDT, up slightly from 75.89 US cents at Friday’s close.