ASIAN currencies slid against the dollar on Monday as investors dumped assets amid heightened fears of a global downturn, forcing central banks in Indonesia and the Philippines to intervene.

The high-yielding Indonesian rupiah bore the brunt of the selling, briefly hitting as low as 10,800 per dollar but later steadied near 10,600 thanks to official intervention.

The rupiah's drop of around 3.5 per cent on Monday took its cumulative decline so far this year to 11 per cent.

A second trader said state banks were selling dollars at 10,600.

The Philippine peso lost 0.8 per cent to 49.385 per dollar, its weakest since December 2006, despite dollar-selling intervention by the central bank to set a floor for the unit.

Some traders said they expected the peso to test the 49.50 level in the near term unless the central bank intervened more aggressively.

The Philippine stock index tumbled 10 percent on Monday, triggering an automatic suspension of trading.

The MSCI index of Asian stocks outside Japan fell for a fourth consecutive session, losing 4 per cent as of 1.20pm, marking its lowest since June 2004.

Meanwhile, the South Korean won dropped as low as 1,447.9 per dollar as investors shrugged off the central bank's move to slash its key interest rate by 75 basis points - the biggest rate cut ever - to calm the jittery market.

Analysts at Goldman Sachs said the won, which has lost 35 per cent against the dollar so far this year, would face further selling pressure in the near term amid the global market turmoil.

'However, we continue to believe that the won/dollar has overshot on the downside and expect the won to strengthen beyond the near term,' they said in a note.

The Japanese yen climbed towards a 13-year peak against the dollar and an all-time high against the Australian dollar as a slide in Tokyo shares overshadowed a G7 warning about excessive yen volatility.

The Group of Seven big industrialised economices said on Monday that a rapid rise in the Japanese yen was bad for both markets and the economy and that it would watch developments accordingly.

Elsewhere, the Chinese yuan was virtually flat at 6.8476 per dollar while the Hong Kong dollar eased slightly to 7.7535 per US dollar after the central bank injected HK$7.75 billion ($1.5 billion) into the market.

Hong Kong's central bank bought US dollars against the Hong Kong dollar last Thursday for the first time in nearly a year to stem a rise in the Hong Kong dollar.

The Hong Kong dollar is pegged to the US dollar and can trade between 7.75 and 7.85 to the US dollar.

Markets in Singapore and Malaysia are closed for holiday.