The World Bank is predicting the global recession will be deeper than it previously thought, with the world economy forecast to shrink 2.9 per cent.

That is far steeper than the 1.7 per cent contraction the World Bank forecast just three months ago.

The large industrial economies of Europe, Japan and the United States are expected to shrink by more than 4 per cent this year, and the bank says the story will be even worse for the world's poor.

The World Bank's gloomy set of figures puts further doubt on the 'green shoots' that so many economic commentators keep referring to - in fact the 2009 forecasts for most economies have been slashed again.

Mick Riordan, a senior economist with World Bank, says there are many impediments to a speedy recovery.

"We're still left with a lot of problems: with high unemployment rates persisting; with capacity utilisation, how much is plant and how much equipment is being used at very low levels; and with fiscal deficits left over from stimulus plans put in place by governments," he said.

"So this all means we're going to have these problems with us for several years to come."

There are also fresh worries about the diminishing flow of private capital into developing countries, which has already fallen by almost 50 per cent this year.

The World Bank says East Asia and the Pacific will be particularly hard hit, and for longer, because of trade links with developed countries.

So too sub-Saharan Africa, which has been hit by falling export prices, a drop in international aid, and a decline in remittances from economic migrants who now have fewer job options overseas.

Mansoor Dailami, the author of the World Bank report, says recovery could take many years.

"The scenario moving forward for the next couple of years is that growth is going to be at subdued levels, investments in many productive sectors, and possibly even in social sectors, as government contracts those expenditures which were very critical for social needs," he said.

"You're going to see an increase in the overall poverty in many of these countries."

However, there will be some growth in the poorer economies, as the World Bank's Andrew Burns explains.

"We are seeing that some of the strength that we are currently seeing in the global economy is coming from developing countries, particularly Chinese demand for imports is rising relatively rapidly. That is sparking some of the recovery or some of the stabilisation that we observe in Japan," he said.

But he also says the sluggish growth is good reason to be cautious.

"Currently almost every high income country in the world, every oeCD country, has got growth at least 4 percentage points below its trend level.

"For developing countries, that same figure, that same calculation comes in about 50 per cent. We have never seen anything like that in the last 40 or 50 years.

"That means that we are not going to have the capacity to export our way into healthier economies, so all of those factors are part and parcel of why we see the rebound that is coming and is going to be there, it is going to be more muted than normal."