The special allocation will be made to IMF members on Sep 9, 30 days after the effective date of the fourth amendment, and will raise the ratios of members' cumulative SDR allocations to quota using a common benchmark ratio as described in the amendment.

The total of SDRs created under the special allocation would amount to SDR 21.5 billion (about $33 billion).

The special allocation will make the allocation of SDRs more equitable and correct for the fact that countries that joined the Fund after 1981 -- more than one fifth of the current IMF membership -- had never received an SDR allocation, IMF said.

The fourth amendment, which was proposed in September 1997, required approval by three fifths of the IMF membership with 85 percent of the total voting power. This threshold has been reached following the recent approval by the US.

The special and general allocations will bring Fund members' cumulative total of SDR allocation to SDR 204 billion (about $316 billion).

The general SDR allocation is a key example of a cooperative multilateral response to the global crisis, offering significant support to the Fund's members in this challenging period, IMF said.