The Australian share market has fallen despite a positive lead from Wall Street overnight.

The benchmark S&P/ASX200 index was down 21.4 points, or 0.31 per cent, to 6,811.7 points at 1200 AEDT on Friday, while the broader All Ordinaries was down 20.7 points, or 0.30 per cent, to 6,921.9 points.

Consumer staple and health care shares had the largest falls, losing 0.85 per cent and 0.59 per cent respectively.

Woolworths was down 1.53 per cent, Coles slipped 0.46 per cent and IGA-supplier Metcash dropped 0.38 per cent.

Biotech giant CSL slid 0.70 per cent, ResMed fell 0.66 per cent and Cochlear was 1.02 per cent lower.

In the same sector, Regis Healthcare was down 17.3 per cent after the nursing home operator lowered its profit guidance amid sliding occupancy rates.

Eight of the eleven ASX sectors were in negative territory at midday including the heavyweight mining and financial segments.

BHP was down 0.53 per cent to $39.58, Rio Tinto was up 0.14 per cent to $102.40 and Fortescue Metals was down 0.14 per cent to $10.935.

The big four banks were lower, with ANZ down 0.40 per cent to $24.79, Commonwealth down 0.67 per cent to $81.18, NAB down 0.42 per cent to $24.915 and Westpac down 0.43 per cent to $24.285.

Bendigo and Adelaide Bank was down 0.25 per cent, Bank of Queensland was up 0.34 per cent and Macquarie Group was down 0.27 per cent.

Only the utilities, property trusts and industrials sectors were able to eke out gains.

The three main indices on Wall Street hit new highs overnight, with the Dow Jones Industrial Average finishing up 0.49 per cent, the S&P 500 was up 0.45 per cent and the tech-heavy Nasdaq Composite was up 0.67 per cent.

The Swedish central bank became the first in the world to emerge from negative interest rates overnight as the Riksbank raised benchmark borrowing costs from minus 0.25 per cent to zero, ending a five year experiment with negative rates.

The Aussie dollar is buying 68.95 US cents from 68.79 US cents on Thursday.