Sales of computers worldwide are set to fall for the first time in eight years.

Companies and individuals lack the money to buy new laptops or upgrade ageing fleets of desktops, analysts believe.

It will mean the first global fall in sales since 2001, when the industry was hit by the combination of 9/11 and the bursting of the dotcom bubble in the stock markets.

Just three months ago many were predicting rises in sales for 2009. However, after recent figures showed technology companies failing to ship as many PCs across the globe as they did last year, experts are beginning to revise their opinions.

Last year saw 300 million personal computers sold across the world with developing countries going online and the introduction of cheaper machines for the mass market.

Towards the end of last year many were predicting a 3-4% rise for 2009 on the basis of low-cost machines making computers more accessible in countries like India and China.

But now some experts believe the market will enter "negative territory" as companies whose offices are lined with banks of PC screens are going to the wall all over the world. Even the booming Asian market has seen a 5% drop in PC sales, according to recent figures.

Loren Loverde of IDC, one of the world's leading technology research groups, said: "We're definitely more pessimistic.

"As things sink in, it could easily be negative territory."

Mark Moscowitz, analyst with bankers JP Morgan, predicted a 13.5% fall in sales this year.

Another factor is the possible introduction of Windows 7, the latest operating software from Microsoft, later this year.

Many potential PC buyers are waiting until it comes out rather than buy machines on the current Vista system.