Australia’s rollercoaster share market has plunged again on a raft of profit warnings, an unprecedented travel ban and cancelled flights.

The benchmark S&P/ASX200 finished Wednesday down 340.2 points, or 6.43 per cent, at 4,953.2, while the broader All Ordinaries index closed down 334 points, or 6.26 per cent, at 4998.8 points.

Meanwhile, the Aussie dollar dropped below 60 US cents for the first time since April 2003, before rebounding somewhat.

At 1615 AEDT it was buying 60.24 US cents, from 60.86 US cents as the market closed on Tuesday.