The All Ordinaries index had added 0.3 per cent, to 5,115 shortly before 12:00pm (AEDT), and the ASX 200 has gained the same amount, to 5,098.
Shares in BHP Billiton were down 1.1 per cent after the company announced half-year profits had halved, and the resignation of its chief executive Marius Kloppers.
Rival Rio Tinto had dropped more, down 1.3 per cent, and Fortescue Metals was down nearly 2 per cent.
Woodside Petroleum, which also reported results this morning, rose more than 3 per cent to $39.10.
Seven West Media's results disappointed investors, with a $109 million net loss due to $260 million in write-downs of its magazine and Yahoo!7 businesses (including Spreets), as well as redundancy and restructure costs.
Excluding those one-off costs, Seven West made a $142.3 million profit, but its shares were down more than 7 per cent to $2.34.
The dollar was also easing, buying 103.39 US cents.