The Australian dollar has fallen after US stocks lost ground following a weak Spanish bond auction.

At 0630 AEST on Thursday, the local unit was trading at 102.56 US cents, down from 102.82 cents on Wednesday.

The Spanish government only achieved the bottom end of its target with the sale of nearly 2.6 billion euros ($A3.35 billion) at a bond auction.

It also was forced to pay higher rates amid concerns over its ballooning public debt.

The Dow Jones Industrial Average was down 0.95 per cent by the close of trade.