WASHINGTON – The authors of a bill to impose a 27.5% tariff on Chinese imports in retaliation for currency manipulation yesterday said they would postpone a vote on the measure until as late as September 29.

Senators Schumer and Lindsey Graham, a Republican of South Carolina, said they decided to delay the vote on their bill after a visit to China convinced them China’s leaders are serious about eventually moving to a floating currency regime.

“We came back from China with a real feeling that the Chinese realized that pegging their currency is not only bad for America, but bad for China as well,” Mr. Schumer told reporters in a press conference following a meeting on Capitol Hill with Treasury Secretary John Snow. Mr. Schumer said he was particularly pleased to see that China’s most recent five-year economic plan included the goal of a floating currency.

The Schumer-Graham legislation would allow for a 180-day period of negotiations between America and China on the currency and if negotiations aren’t successful, then the tariff would be imposed on all imports from China. The measure received 67 votes of support when it was attached to an unrelated bill last year.

Last summer, China revalued the yuan 2.1% stronger against the dollar and said it would allow the yuan value to fluctuate by 0.3% plus or minus against a basket of currencies. Since then, the yuan has appreciated only about 1.0% further.

Messrs. Schumer and Graham said that isn’t enough, though neither would quantify how much yuan appreciation would satisfy them.

“I’m willing to abandon the need for tariffs if the Chinese embark on real reform; we’re not there yet,” Mr. Graham said.

They senators said that should China fail to move toward a more flexible currency, they could call for a vote on their bill before September 29.

“We are keeping our legislation at the ready because if there aren’t results, we will use that blunt but effective tool,” Mr. Schumer said.

Mr. Snow met with Messrs. Schumer and Graham yesterday to discuss their trip to China.

The meeting showed that Snow and the senators are in agreement that “economic reforms in China need to continue apace,” Treasury spokesman Tony Fratto said. However,Treasury remains opposed to punitive tariffs in Messrs. Schumer and Graham’s proposed legislation, he said.

The Treasury spokesman said it is too early to comment on planned foreign exchange policy legislation from Senate Finance Committee Chairman Charles Grassley, a Republican of Iowa, and ranking Senate Finance Committee Democrat, Max Baucus of Montana.