The sharemarket lost ground as the big miners fell on lower commodity prices and downgrades of Chinese growth forecasts.
At the close on Wednesday, the benchmark S&P/ASX 200 Index was down 29.3 points, or 0.56 per cent, at 5191.7. The broader All Ordinaries fell 29.2 points, or 0.56 per cent, to 5173.3.
The falls went against the flow in overseas markets after US, European and Asian markets posted strong gains, CMC Markets senior trader Tim Waterer said.
"Investors in the big-name mining stocks seemed a little unnerved by commodity price weakness and concerns about China, which impact on resources," he said.
JPMorgan has cut its estimate for China's economic growth this year to 7.6 per cent, from 7.8 per cent, following disappointing April industrial output data.
Commodity prices were weaker, with some including oil and gold affected by renewed strength in the US dollar.
Among the mining companies, BHP Billiton dived 64¢ to $34.03 after new chief executive Andrew Mackenzie signalled plans to slash capital spending by almost a fifth.
Rival Rio Tinto fell $1.78 to $55.77 and iron ore miner Fortescue Metals lost 15¢ to $3.59.
The banks were mixed. Commonwealth Bank gained 56¢ to $72.65 after it said its third-quarter profit was up 12 per cent to $1.9 billion. Westpac tumbled 8¢ to $31.67, ANZ increased by 9¢ to $29.98 and NAB dropped 3¢ to $33.07.
CSR shares fell 1.5¢ to $1.95, recovering some heavy losses earlier in the day after the building products supplier recorded a full-year net loss of $146.9 million, including the write-down of its Viridian glass business.
Utilities stocks were the strongest performers, led by electricity and gas company Origin Energy, up 16¢, or 1.3 per cent, to $12.80.
National turnover was 1.48 billion securities worth $4.68 billion.
Meanwhile, bond futures prices were lower as the US dollar and Wall Street gained ground after a run of positive economic data from the world's largest economy.
CBA interest rate strategist Philip Brown said bond futures prices eased as optimism about the US economy encouraged traders to move out of Australian assets.
"The US data has been a bit all over the place, but after some weakness a couple months ago it's getting a bit better," he said.