At midday AEDT on Monday, the benchmark S&P/ASX200 index was down 5.1 points, or 0.07 per cent, to 7,638.5, after being up by as many as 39.8 points, or 0.5 per cent, in the first hour of trading.
The broader All Ordinaries was down 4.8 points, or 0.06 per cent, to 7,894.4.
The ASX's 11 sectors were mixed at midday, with six down and five up. Energy was the biggest mover, falling two per cent as Brent crude hit an 11-day low of $US81.20 a barrel. Woodside was down 1.7 per cent and Santos had fallen 4.5 per cent.
The heavyweight mining sector was up 0.2 per cent, with BHP dipping 0.7 per cent and Rio Tinto down 0.2 per cent, while Fortescue had added 0.4 per cent.
Kogan.com had soared 20.6 per cent to a two-year high of $7.30 after the e-retailer said it would resume paying dividends, which it had suspended for three years during the turbulence of the COVID-19 pandemic.
Director Ruslan Kogan said while the group's transformation to a more efficient platform and software-based model was in its early days, he was never more confident about the outlook for the 18-year-old business.
Endeavour Group was down 4.3 per cent to a more than one-year low of $5.035 after the alcohol retailer said its net profit fell 3.6 per cent to $351 million for the six months to December. So far in the second half, sales were subdued in January but picked up in February, Endeavour said.
The Big Four banks were having a fairly quiet morning, with ANZ flat, Westpac down 0.1 per cent, NAB dipping 0.3 per cent and CBA up 0.4 per cent.
In small caps, NextEd Group had plunged 30.5 per cent to a more than three-year low of 36.5c after the tertiary education provider issued a trading update.
The Australian dollar was buying 65.60 US cents, from 65.70 US cents at Friday's ASX close.