Australian stocks have suffered their worst loss in three weeks after the price of oil was smashed to its lowest level since 1999.

The S&P/ASX200 benchmark index finished Monday down 134.5 points, or 2.45 per cent, to 5,353 points, while the All Ordinaries index was closed down 130 points, or 2.34 per cent, to 5,414.

The Australian dollar was buying 63.44 US cents, up slightly from 63.40 US cents at Friday’s close.