U.S. Federal Reserve Chairman Ben Bernanke warned on Monday that Asian policies promoting exports could lead to a reemergence of imbalances in trade and capital flows, which some believe helped fuel the U.S. housing bubble.

Trade surpluses achieved through policies that artificially enhance domestic saving and export industries distort the allocation of resources, he said.

To achieve more balanced and durable economic growth and to reduce the risks of financial instability, we must avoid ever-increasing and unsustainable imbalances in trade and capital flows, he said in comments prepared for delivery to a San Francisco Fed conference on Asia.

Bernanke said imbalances have narrowed following the crisis, but warned that as the global economy recovers and trade volumes rebound, global imbalances may reassert themselves.

The Fed chairman said that that Asian economies had rebounded strongly from the crisis, with annualized growth rates in the double digits expected in China, Hong Kong, Korea, Malaysia, Singapore, and Taiwan.

At this point, while risks to the economic outlook certainly remain, Asia appears to be leading the global recovery, he said.

Countries with the most open economies, such as Singapore, Hong Kong, and Taiwan took the biggest hits as a result of the turmoil, he said. China, India, and Indonesia, which are among the least financially open economies, expanded throughout the crisis, Bernanke said.

However, while conceding that greater global integration increases vulnerability to world-wide economic shocks, he said greater openness would promote stronger growth over the longer term.

Protectionism and the erecting of barriers to capital flows should thus be strongly resisted, he said.

(Reporting by Mark Felsenthal; Editing by W Simon