Four developing nations, including China, could see their power increased within the IMF, a report has said.
China's economy has boomed since the IMF was formed
The Financial Times said that China, South Korea, Turkey and Mexico might gain increased voting rights.
The move is part of broader plans to overhaul the fund, to be discussed at the IMF's annual meeting in September.
The fund's voting structure has been criticized for being anachronistic and failing to reflect the growth in developing nations' economies.
Countries' voting rights in the IMF are meant to be an indication of their economic strength, with the US, for example, having the single largest quota of 18.7%.
But such rights have changed only slowly since the fund was set up in 1945, when they largely reflected the economic strength of the US and Europe.
Since then developing nations, such as Brazil, India and China, have grown significantly.
However, this has not been evident in the IMF's power structure and the US and Europe still dominate the fund.
Changes to voting rights for China, South Korea, Turkey and Mexico could happen in a "few days", the FT quoted IMF managing director Rodrigo Rato as saying.
"There is consensus that we should address these in a package of reforms that should be launched [in] Singapore," he said.
The news comes after Mr Rato was commissioned in April to formulate changes to the fund's voting structure.
Back then Mr Rato said: "This is an institution based on the representation of countries based on their economic weight in the world economy. The world economy is not a frozen thing, it changes over time."
As well as altering the voting structure, plans to overhaul the IMF have included proposals to give the organisation a stronger role in policing countries' exchange-rate policies.