November 21, 2008 - 9:13AM

The Reserve Bank of Australia says it intervened in the foreign exchange market to support the Australian dollar on Friday morning, as the local currency fell under 61 US cents for the first time in four weeks.

''Yes, we provided liquidity as on previous occasions,'' an RBA spokesman said. ''We don't disclose when, nor do we disclose the level.''

The Australian dollar sunk to a four-week low of 60.80 US cents at 7.40am (AEDT), after opening at 61.31 US cents only 40 minutes earlier.

The currency's low point occurred as Wall Street's Dow Jones Industrial Average was on the way to finishing the New York session 5.5% weaker, hitting a five-and-a-half-year low of 7,560.49.

The domestic currency fell during offshore trade after data showed Japanese exports fell by 7.7% in the year to October, marking the sharpest annual decline since December 2001.

Japan, Australia's biggest export market, also posted a surprise trade deficit of Y63.9 billion ($!.05 billion) in October, from a trade surplus of Y999.4 billion ($16.38 billion) a year earlier, the nation's Finance Ministry said.

The RBA last intervened in the foreign exchange market on November 13, when the Australian dollar fell to 63.50 US cents, and on October 28, when the currency fell to a five and a half year low of 60.12 US cents.

In late October, the central bank spent $3.15 billion propping up the Australian dollar, a bigger amount than in early 2001 when the unit hit an all-time low of $US0.4778.

Earlier, ANZ senior markets dealer Alex Sinton said the RBA was likely to intervene in the currency market, predicting the Australian dollar would fall to 60.80 US cents as Wall Street closed weaker.

''The central bank activity is going to smooth things,'' he said from Auckland.

AAP