That’s down from a global growth rate of 3.8 percent in 2007 — and the downturn is expected to continue in 2009 with only slightly higher economic growth of 2.1 percent, the UN report said.

The mid-year update of the UN World Economic Situation and Prospects 2008 blamed the downturn on further deterioration in the US housing and financial sectors in the first quarter which "is expected to continue to be a major drag for the world economy extending into 2009."

But the UN said developing countries won’t suffer as badly.

They should grow by 5 percent this year and 4.8 percent next year, compared to a robust 7.3 percent in 2007.

The UN economists said the deepening credit crisis in major market economies triggered by the US-led slump in house prices, the declining value of the US dollar, persistent global imbalances, and soaring oil and commodity prices "all pose considerable risks to economic growth" in both developed and developing countries.

"The baseline forecast projects a pace for world economic growth of 1.8 percent in 2008," the UN report said.

But it said the final figure will largely depend on developments in the United States.

Global growth this year could fall to 0.8 percent if the US sub-prime mortgage market turmoil has a more serious impact on developing countries and countries in transition, the UN report said.

But if the monetary and fiscal measures the US government has take to stimulate the economy – including tax refunds and lower interest rates – boost consumer spending and restore confidence in the business and banking sector, the world economy would only slow to 2.8 percent growth this year and 2.9 percent in 2009, it said.

The report, prepared by the U.N. Department of Economic and Social Affairs, forecast that U.S. economic growth will decline from 2.2 percent in 2007 to -0.2 percent this year, with only slight recovery in 2009 to 0.2 percent growth.

"At issue is how deep and long this contraction will be," the report said. "As the housing slump continues and the credit crisis deepens, a broad array of ... indicators are already hinting at a recession."

It cited a decline in U.S. employment, consumer confidence at its lowest level in a decade, household spending growth slowing sharply, and business equipment spending slowing alongside large inventories of housing and a 30 percent decline in residential investment.

This strongly suggests "that the implosion of housing activity will not stabilize until 2009," the U.N. report said.

As for other developed countries, the U.N. forecast that Japan’s economic growth will decline from 2.1 percent in 2007 to 0.9 percent in 2008, and that Western Europe’s growth rate will drop from 2.6 percent last year to 1.1 percent this year.

Despite the slowdown in global economic growth in 2008, the U.N.

said global inflation is expected to accelerate this year to 3.7 percent.

The report said the recent sharp rise in commodity prices, and the continued rise in oil prices are key factors spurring inflation along with higher wages.

The growth of world trade also slowed from 7.2 percent in 2007 to 4.7 percent in early 2008, largely due to weak U.S. demand for imported goods, it said.

The U.N. report said "a number of developed countries with some weight in the world economy like Japan, Germany, Switzerland, the Netherlands, Norway and Canada, as well as the emerging-market economies in East Asia and the main oil exporters have a decisive role in engineering a more balanced and sustainable path of economic growth."

These countries "have much to gain" from deploying some of their vast accumulated monetary reserves to improve infrastructure, social services, and further diversify their domestic economies, it said.