The Australian sharemarket finished sharply lower on Thursday as the big miners sank on weaker metal prices.

At the 1615 AEST official market close, the benchmark S&P/ASX200 index slipped 1.2 per cent to 4,605.3 points, while the broader All Ordinaries index eased 52.7 points, or 1.1 per cent, to 4650.

Among the sectors, materials fell 1.5 per cent, financials lost 1.7 per cent and industrials slipped 0.5 per cent. The only sector in the black was gold, which gained 0.9 per cent on safe-haven buying.

Banks and miners dragged the market lower, as a lack of solid developments overnight failed to push the market higher after its latest rally, according to CMC Markets head of sales trading Matthew Lewis.

"It was fair enough, considering the run-up we've had this week and a lack of any material developments overnight to spur buying activity,'' he said. ''We've seen the market break out of its range in the past few sessions, and given the downside risks, it wasn't surprising to see a few profit-takers move in today.''

Softer commodities prices overnight saw the big miners in the red. BHP Billiton reversed 1.74 per cent to $38.75. Meanwhile, Rio Tinto lost 2 per cent to $73.79, while junior miner Fortescue Metals Group shed 3.37 per cent to $4.86.

In the banking sector, Commonwealth Bank was down $1.16, or 2.2 per cent, at $52.64, Westpac had dropped 35 cents, or 1.5 per cent, to to $23.28, ANZ dipped 50 cents, or 2.1 per cent, to $23.66 and NAB was 16 cents weaker at $25.78.

"Today's bright spots could be found in the consumer staples space. We saw Foster's, Coca-Cola and Woolies all make solid gains," Mr Lewis said.

"Today was really about the market coming off the boil. We've seen the market break out of its range in the past few sessions, and given the downside risks, it wasn't surprising to see a few profit takers move in today."