Meeting in Italy this week, world leaders will seek accord on an agenda including trade, global warming, and steps to loosen the grip of the recession.

Less formally, but almost unavoidably, the meeting of the Group of Eight -- G-8 -- in the Italian mountain town of L'Aquila is likely to fuel ongoing debates over the continuing usefulness of two traditional economic institutions -- the pre-eminence of the U.S. dollar in world trade and the G-8 itself.

The G-8 dates to the 1970s. It started as a meeting of six leading industrialized democracies and member countries now are Canada, Russia, France, Germany, Japan, the United Kingdom and the United States. In recognition of the emergence of new economic realities, deliberations now include the Outreach 5, including China, India and Brazil, who consult with the older members of the group, but do not host its annual summits or share in its rotating presidency.

"On the economic side, I think they ought to get rid of it," said Barry Bosworth, an economist and senior fellow at Washington's Brookings Institution. "It has been supplanted by the G-20, [which is] not perfect, but a much more open Democratic forum for discussing these issues."

The G-20, organized during the Clinton administration, is the overlapping but broader group of economies that last met in London in April, and will reconvene in Pittsburgh in September.

"If you stick with the G-8 and its original members, it's too small to do much," said Marvin Goodfriend, a professor of economics at Carnegie Mellon University's Tepper School of Business. "That's because the center of gravity of the world economy has shifted to the east with China and India."

The consultations that begin this morning follow months of calls by officials from countries including China, Russia and Brazil for a reassessment of the dollar's role as the world's de facto reserve currency. The international recession combined with the continuing prospect of U.S. deficits have spurred concerns over how well the currency can be expected to hold its value in years to come. Those fears are most acute in China, the biggest U.S. creditor, whose massive store of dollar-denominated assets would be battered if inflation proved to be a sequel to the current downturn.

"The Chinese seem to be pressing on the currency issue," said Desmond Lachman, a fellow of the American Enterprise Institute and a former executive of the International Monetary Fund. "They've expressed some concern that the U.S. budget is out of control."

When President Barack Obama was campaigning in Pittsburgh, still seeking the Democratic nomination, he was asked about the U.S. interest in protecting the future of the dollar as a reserve currency. It seemed a remote, theoretical issue then. A year later, it's one of the threads in the overall debate on the troubled world economy.

"I think it is a problem because the fact that we are the world currency has frankly given us an advantage in world trade," Mr. Obama told Post-Gazette editors. "There's been a premium that we've been able to extract from other countries for the use of our currency for everything under the sun."

Mr. Obama's initial prescription was to reduce the deficit. But that was before the depths of the economic downturn made the case for immediate government stimulus more compelling to his administration and to the Democratic majority in Congress.

Mr. Obama said that the surest way to buttress the dollar was to reduce the nation's trade deficit by curbing U.S. reliance on foreign oil and its fiscal deficit by reining in the costs of entitlements and health care.

"Part of the problem is now that people are looking at the long term, and they're saying China is making better economic decisions on a lot of fronts than we are," he said of the anxieties of trading partners that the nation relies on to finance its debt.

In the near term, however, despite the problems of the U.S. economy, experts said that the lack of a credible alternative protected the central role of the dollar in world trade.

"It's easy to say that the U.S. is printing money like it's going out of fashion, but what is the alternative?" Mr. Lachman observed.

"The Euro and the Yen? Their economies are in even more difficulty."

Some Chinese officials have talked of a more assertive role for their currency, the renminbi, as a basis for world trade. But, for the foreseeable future, that prospect is hobbled by the fact that it is not freely convertible abroad and its value is managed by the government.

"The euro is a more formidable competitor," Mr. Goodfriend said. "It has an independent central bank managing it with a convertible exchange rate, but the [European Union] has its own problems and it's not clear that it's a better alternative than the dollar."