Average growth is expected to dip by 0.4 percentage points but remain strong at 4.6 percent in the eight central European states that joined the EU last year, the Unece economic survey for 2005 said.
That compares with forecast growth in the 12-nation eurozone -- including the traditional industrial powerhouses, France and Germany -- of 1.8 percent, 0.1 percentage points less than in 2004.
Britain's growth rate is also expected to slow from 3.2 percent to 2.5 percent, the biggest decline predicted in the European Union in 2005.
The healthiest economies in the EU this year are likely to be the smaller ones, the Unece's data indicated.
The countries where growth is expected to accelerate are Austria, Belgium, Cyprus, the Czech Republic, Denmark, Ireland, Italy, the Netherlands, Portugal, Malta and Slovenia.
Economic growth is likely to remain stable in Finland and Hungary.
"A noticeable surge" in new foreign direct investment projects or manufacturing plants in central European and Baltic states "should accelerate the ongoing process of restructuring" there, the survey said.
But it warned that they were vulnerable to a possible sharp deceleration of growth in western European markets and higher than expected energy prices.
The UN predicted that the global economy will expand by an average of 4.25 percent in 2005, down from five percent in 2004.
China and the slowing US economy are set to remain the principal engines of global growth, although Asian emerging markets and Latin America were expected to post "rapid" growth rates, it added.
The Unece said the eurozone would owe its expansion to exports rather than internal demand.
"In view of the fragility of factors of domestic growth and the dampening effects of the stronger euro on domestic economic activity and inflation, monetary policy in the euro area is likely to continue to 'wait-and-see'," it added.
The report also warned that the reliance on the United States made the global economy and the EU vulnerable to a more pronounced slowdown in the US economy.
It underlined that the widely demanded correction in the huge US current account deficit could trigger "sudden and sharp changes" in international capital flows, while strong consumer demand in the US was fragile.
"The orderly reversal of the deficit is a major challenge for policy makers in both the United States and other economies," the Unece said.