The Australian dollar fell slightly against its US counterpart following a downgrade to Britain's credit rating.

At 6.30am AEDT the currency was trading at 103.05 US cents, down from 103.13 cents at Friday’s local close.

Ratings agency Moody's downgraded Britain's credit rating to AA1, stripping it of its prized AAA rating and warning that growth is likely to remain sluggish for several years.

Meanwhile, markets are nervously awaiting an outcome from the Italian elections amid fears the poll results could spell trouble for the eurozone. Italian polls will reopen tonight AEDT for the second of two days of voting.