At a meeting in South Korea, they agreed a shift of about 6% of the votes in the IMF towards some of the fast-growing developing countries.
Those nations will also have more seats on the IMF’s Board, while Western Europe will lose two seats.
But the US will retain the veto it has over key decisions.
Such decisions require an 85% vote – Washington holds 17% under the IMF’s weighted voting system.
The ministers also agreed to refrain from competitive devaluations of their currencies and move towards more market-determined currency systems.
The talks in the city of Gyeongji come against a background of strains in financial markets which some have called a currency war…