At noon on Monday the benchmark S&P/ASX200 index was down 6.7 points, or 0.1 per cent, to 7,008.9, while the broader All Ordinaries was down 2.9 points, or 0.04 per cent, to 7,247.4
The energy sector was up 0.9 per cent and mining was up 1.4 per cent, buoyed by a surge in OZ Minerals shares after BHP made an $8.4 billion play for the copper miner.
But the ASX's nine other official sectors were lower.
Property was the biggest laggard at midday, falling 1.63 per cent following last Friday's stronger-than-expected US employment numbers.
US Federal Reserve Governor Michelle Bowman cited the figures on Saturday in arguing the central bank should continue its 75 basis point rate hikes until inflation is tamed.
Charter Hall and Stockland were both down 2.2 per cent, and Growthpoint Property had fallen 2.5 per cent.
OZ Minerals meanwhile had rocketed 34.7 per cent to a three-month high of $25.49 after the copper mine's board rejected an $8.4 billion, $25-per-share offer from BHP.
With compelling synergies between the two companies' SA and WA-based mining assets, traders appeared to be betting that an improved offer would materialise.
BHP was up 0.4 per cent to $38.97, Fortescue Metals had risen 3.7 per cent to $18.81, and Rio Tinto had added 2.1 per cent to $99.83.
As reporting season started in earnest, Aurizon Holdings had fallen 5.7 per cent to $3.81 after the rail freight operator announced its full-year earnings had dropped one per cent to $1.47 billion.
Weather and COVID-19 disruptions had offset cost reductions, along with an escalation of revenue from rail contracts linked to inflation, the company said.
Suncorp was down 6.5 per cent to $10.89 after the insurer said its full-year net profit after tax fell 36.7 per cent to $681 million, modestly missing expectations.
Suncorp said the La Nina weather pattern had led to 35 separate weather events and about 130,000 claims in Australia and New Zealand, blowing out its natural hazard allowance by $101 million.
Commonwealth Bank was up 1.2 per cent to $102.60 after the banking behemoth said it would recognise a $516 million profit on the sale of its 10 per cent stake in Bank of Hangzhou when it announces its earnings on Wednesday.
The other big banks were lower, with Westpac dipping the most, by 0.7 per cent.
Meanwhile the Australian dollar was buying 69.31 US cents, down from 69.66 US cents on Friday.
