(refiles to correct Kuroda's first name in paragraph 13)
* Asia important player in reducing global imbalances
* Study says Asia has to address weakness on governance, institutions (Recasts with ministers at seminar on 2050 report)
By John Mair and John Ruwitch
HANOI, May 4 (Reuters) - Asia could dominate the world economy by 2050, provided it avoids the traps that have seen other emerging countries stall, and that meant it has to do its part in reducing global imbalances, top policymakers said on Wednesday.
French finance minister Christine Lagarde said Asia could not be a bystander in the Group of 20's drive for "solid, sustainable and balanced" global growth, while China's deputy finance minister Li Yong said the region should speak with one voice.
"That's priority number one: trying to reduce the level of surpluses and deficits by agreeing to more balanced (development) in relation to our own development and the development of other countries," Lagarde said at the Asian Development Bank's annual meeting.
"Asia is not a passenger in that game," she said at a seminar on an ADB report that the region could account for 51 percent of global output by mid-century. [ID:L3E7G337B]
ADB said Asia could achieve such prominence if its major economies avoid the middle-income trap, where emerging economies stall in their transition to growth based on high productivity and innovation, the ADB said.
Successful transition would bring prosperity to some 3 billion people in the region a generation earlier than otherwise would be the case.
Lagarde was in Hanoi for the ADB's meeting, which includes a G20-IMF session on reforming the international monetary system. France holds the G20 presidency this year.
The G20 has reached a deal for seven countries that each account for more than 5 percent of the group's combined output to have their policies examined by the International Monetary Fund with a view to preventing a repeat of the global crisis.
The list includes the debt-burdened United States and export-rich China -- the two main economies at the heart of the debate over global imbalances -- along with France, Britain, Germany, Japan and India. [ID:nN15205055]
The IMF will look at national levels of debt, budget deficits and trade balances to determine if a nation's policies are putting the global economy at risk and should be changed -- but countries are not required to follow its recommendations.
China's Li said Asian countries needed to strengthen communication and coordination on economic policy.
"We should speak with one voice," he said.
"It is imperative to strengthen regional cooperation and promote integration of the Asian economy."
ADB President Haruhiko Kuroda said there was agreement imbalances needed to be reduced in Asia and the rest of the world.
"Global imbalances are on the rise again, although at this moment global imbalances are not anything near to the pre-crisis peak," he told the seminar.
"Still, we are concerned about this fact." (Editing by Tomasz Janowski)