Stock markets across the Asia-Pacific region have tumbled after a raft of gloomy US economic data sent Wall Street plunging to a six-year low.

With few investors in a buying mood, Japan's benchmark Nikkei index fell 1.35 per cent by midday on Friday, Hong Kong was down 2.2 per cent, Sydney slipped 1.5 per cent and Seoul lost 1.4 per cent.

The falls came after the Dow Jones industrial average fell 1.19 per cent on Thursday, hitting its lowest point close since October 9, 2002.

Underscoring jitters about the state of the world's number one economy, a US government report showed the number of Americans claiming unemployment benefits had hit a record high of almost five million.

With about half a million US jobs being lost every month, analysts are warning of another substantial contraction in the US economy in the first quarter of the year.

Analysts said the continuing rise in claims spelled bad news for consumer spending, which drives nearly two-thirds of US economic activity.

US investors remain unconvinced that the $787bn economic stimulus bill signed into law this week will have a significant impact.

That, in turn, is bad news for Asia, whose export-dependent economies rely heavily on the US market.

Earlier this week Japan, already in its worst recession in decades, reported its steepest economic contraction since 1974.

So far this year Japan's Nikkei has lost 15.8 per cent, Hong Kong's Hang Seng 11.6 per cent and the Dow Jones industrial average is down 14.9 per cent.