Mr Paulson says the crisis in the US housing market poses risks

China's reluctance to revalue its currency and the sliding dollar had also come under the spotlight at two-day summit of G20 members.

The group agreed volatile and erratic currency movements were unwelcome.

But the summit's final communique stopped short of labelling specific currencies as being problematic.

The G20 called for greater exchange rate flexibility from countries with large current account surpluses in an apparent reference to China.

China has been under mounting pressure from the United States and other trading partners to allow its tightly controlled yuan to strengthen to correct global trade imbalances.

No finger pointing

France's Finance Minister, Christine Lagarde, said group discussions did not specifically point a finger at any particular currency.

"We all concurred that the currency situation is one that needs a joint approach, concerted approach. Clearly we don't want to point the finger at anyone and we want to operate by consensus," Lagarde said.

I view the US housing market as the most significant current risk to our economy US Treasury Secretary Henry Paulson

The G20 warned of a likely slowdown in global economic growth but said it was expected to be modest.

"Its extent and duration remains difficult to predict," said the communique ending the summit.

"We also agreed that an orderly unwinding of global imbalances, while sustaining global growth, is a shared responsibility," the communiqu� said.

It also said that G20 members would need to assess the inflation outlook in light rising commodity prices and the prospect of slower growth.

US Treasury Secretary Henry Paulson said the wider economy faced risks from problems in global credit markets and the sub-prime crisis in the US housing market.

"In discussions on the decline in the US housing market, I noted it is still unfolding and I view it as the most significant current risk to our economy," Mr Paulson said, adding he was confident that the US economy would keep growing despite the housing strains.

IMF reform

Meanwhile, the new managing director of the International Monetary Fund, Dominique Strauss-Kahn, promised to make substantial progress on developing countries' demands for a bigger voice in the institution.

Mr Strauss-Kahn has vowed to reform the IMF

Mr Strauss-Kahn said the G20 agreed that developing nations should have a bigger voice in the IMF, where, under a system devised 63 years ago, richer countries have more power.

The weight of each nation's vote is tied to its quota, which is determined by the size of their economy, currency reserves and openness to trade and capital flows.

"The fund needs to be reshaped," Mr Strauss-Kahn said.

"Times have changed. Some emerging countries have much more economic influence than they had."

What could not be agreed was which nations would give up quotas and votes, he said.

"The result must be a shift in quotas from developing countries to emerging ones. The question is how big is this shift going to be - who is going to lose [some quotas], who's going to win."

The G20 brings together developed and emerging economies that together represent two-thirds of the world's population, 90% of gross domestic product and more than 80% of world trade.