Developing countries have voiced doubts whether an IMF proposal to overhaul the voting power of member countries was adequate but acknowledged it will likely be endorsed in a vote that closes on Monday.
The plan will immediately increase the IMF votes of four countries - China, South Korea, Mexico and Turkey - and will be followed by a second stage of broader reforms to recognise the growing weight of emerging nations in the global economy.
A resolution on the proposed changes is being voted on by the IMF's 184 member countries at IMF meetings in Singapore.
The first round of vote adjustments will hoist China, now the world's fourth-largest economy, to number six from number nine in the IMF's vote rankings.
A communique by the Group of 24 developing countries said the ad hoc increases for the four countries was welcome, but said the package did not address "the fundamental issue of the underrerpresentation of developing and low-income countries as groups".
The G24 includes Argentina, Brazil, Colombia, Egypt, Iran, Pakistan, Mexico, Peru, India, Venezuela, South Africa and Nigeria. China is an observer country.
The communique said emerging and developing countries account for more than half of global gross domestic product (GDP) measured in purchasing power parity and hold most of the world's reserves.
"In order to reflect this new reality in the world economy and increase the legitimacy and relevance of the (institutions), the voting power of developing countries and low-income countries as groups should be expeditiously increased and protected," the G24 said.
The communqiue said any reforms should accurately reflect the relative economic size of developing countries in the world economy.
Separately, Brazil, India, Argentina and Egypt issued a joint statement saying a second round of adjustments to give emerging nations more say was by no means guaranteed.
"We and several other important emerging markets and developing countries representing a substantial share of the global economy and population are opposed to the resolution," the statement said.