Aussie dropped two-thirds of a cent on the day to $0.9672 at 0155 GMT, pulling in closer to Thursday's 11-month low of $0.9593.
A break of $0.9581, the 2012 trough, would open the way to $0.9388, the weakest since Oct 2011.
The kiwi slipped to $0.8092, from $0.8145 early, having touched an 8-1/2-month low of $0.8006 this week.
Undermining sentiment was a sharp fall in Australian stocks, led by the nation's major banks.
Traders said heavy selling by Japanese retail investors forced out of long AUD/JPY positions on margin calls also weighed on the Aussie.
Volatility in FX, stocks and commodities on Thursday is making investors hesitant to take fresh positions.
Aussie sank deeper on a trade-weighted basis, hitting a fresh low of 74.0, its weakest since early June 2012. It was hovering near 18-month lows against the euro.
Kiwi held around a two-month trough on a trade-weighed basis.
The Antipodean currencies have skidded more than 5.5 percent so far this month, on speculation the US Federal Reserve may start tapering off its super easy monetary policy this year. The Aussie and kiwi were also hard-hit by concerns about China's economic recovery.
Data out in New Zealand showed a smaller-than-expected trade surplus in April, as growth in imports outpaced the rise in exports.
Australian government bonds futures fell, with the three-year contract 0.030 points lower to 97.380, with the 10-year contract off 0.05 basis points to 96.655.
New Zealand government bonds eased, sending yields five basis points higher along the curve.