For two years, Treasury Secretary John W. Snow has pushed and prodded China to let its currency float more freely.

Though they have hedged their demands in public, administration officials have urged Chinese officials in private to let their currency float freely.

After the central bank said yesterday that it would let the currency float, the exchange value dropped as much as 20 percent, to 29.50 baht to the dollar offshore.

American pressure on China to let its currency float has been unsuccessful so far.

For example, China's decision to let its currency float against the dollar could ultimately make the outlook less certain for companies that derive a significant share of their profits overseas.

For these economies to have an independent monetary policy, it had to let its currency float against the main currencies in the world.

Treasury officials are hoping that the fund could put new public pressure on China to let its currency float more freely.

But leading economists have warned that letting the Chinese currency float on the market could cause more problems than it solves.

After Mexico's central bank decided that it could no longer defend the peso from speculators, the Government was forced to let the currency float against the dollar on Dec. 21.

Mr. Sachs advocates letting the Brazilian currency float, a path Mr. Fischer has rejected as too likely to encourage a price spiral.