The share market has closed lower for a third straight session, slumping in afternoon trade as copper joined the long list of commodities suffering price falls.

At the close on Wednesday, the benchmark S&P/ASX200 index was down 51.1 points, or 0.95 per cent, at 5,353.6, while the broader All Ordinaries index was down 49.9 points, or 0.93 per cent, at 5,332.2, according to preliminary figures.

On the ASX 24, the March share price index futures contract was 52 points lower at 5,301, with 29,281 contracts traded.