(Adds Brazil comment; changes slug from CHINA-ECONOMY/CURRENCIES)

By Simon Rabinovitch and Matt Falloon

L'AQUILA, Italy, July 9 (Reuters) - China called on Thursday for reform of the reserve currency system at a meeting of world leaders in one of its most direct attacks on the dollar's global dominance.

Chinese State Councillor Dai Bingguo did not specifically name the dollar at talks between the Group of Eight rich nations and G5 emerging powers, but he was unequivocal in calling for the world to diversify the reserve currency system and aim at relatively stable exchange rates.

France also unexpectedly called for a currency discussion and moving toward a "multimonetary" system, though Britain warned any debate should be reserved for the long term to avoid destabilizing markets in the midst of a global recession.

China's ideas for changing the system had previously been mentioned in reports by its central bank, but had never been voiced in a speech by such a high-ranking political leader.

"We should have a better system for reserve currency issuance and regulation so that we can maintain relative stability of major reserve currencies' exchange rates and promote a diversified and rational international reserve currency system," Dai told the summit in Italy, according to a statement read by Foreign Ministry spokesman Ma Zhaoxu.

Dai made his statement to a meeting including British Prime Minister Gordon Brown, U.S. President Barack Obama and the leaders of Japan and the European Union, whose currencies are often held as part of countries' foreign exchange reserves.

There is no question on whether the comments represented those of of China's top leadership, the spokesman said.