Continued robust expansion in developing countries will help offset a slowdown in the United States this year amid concerns of a possible recession in the world's largest economy, the World Bank said Wednesday.

The Washington, D.C.-based international bank forecast global growth of 3.3 per cent this year from 3.6 per cent in 2007.

"Developing countries, if you add them all up now, are basically the same size as the United States," said Hans Timmer, co-author of the bank's annual Global Economic Prospects report.

"But they are growing more than three times as fast, and that means that their contribution to global demand is more than three times as important as the contribution of the United States," he said at the launch of the report in Singapore.

Not only has the resilience of developing economies mitigated the slowdown in the U.S. economy, it has also helped reduce global trade imbalances by sucking up American exports with the help of a cheaper U.S. dollar, he said.

The bank said there were concerns that a faltering U.S. housing market or further financial turmoil could push the U.S. into recession and weaken demand for the products of developing countries.

"We still don't know exactly how many corpses are there still in the financial markets, and how big, ultimately, the losses will be," Timmer said.

The bank believes, however, that the spillover from problems in the U.S. housing market on consumer demand will be limited. It expects the U.S. economy to regain momentum and lead to an increase in world output, which it predicts will expand by 3.6 per cent in 2009.

Gross domestic product growth for developing countries is expected to ease to 7.1 per cent in 2008, while high-income countries are predicted to grow by a modest 2.2 per cent, the bank said.

Timmer warned, though, that some developing economies were in danger of overheating, which would be exacerbated if interest rates come down sharply as a result of a U.S. economic slowdown, creating excessive liquidity in the global economy.

If capital flows turn away from the United States because of the problems there, the funds will end up "somewhere in the developing world and that mechanism could create new bubbles or expand bubbles already in the making," Timmer said, citing the Shanghai market and stock markets in India as examples.

The Shanghai composite index soared 97 per cent last year, making it the world's best-performing major benchmark index. It also became the second most popular place for initial public offerings behind New York.

"You can argue that that kind of an increase is probably not sustainable," Timmer said.

Further sharp declines in the U.S. dollar are also a potential threat, despite the boost provided to U.S. exports. A less robust greenback provokes increased uncertainty and volatility in financial markets and increased trading costs, resulting in weaker export and investment growth worldwide, the report said.

And while a weaker dollar would benefit developing countries with dollar debt, it would also impose losses on those that hold dollar-denominated assets, the bank noted.

To alleviate poverty, the report urged developing countries to harness better technology, saying that rapid technological progress in developing nations has helped to reduce the proportion of people living in absolute poverty from 29 per cent in 1990 to 18 per cent in 2004.