After his effort to strengthen a provision guaranteeing special treatment for Libby residents was rejected on Thursday, Montana Democratic Sen. Max Baucus voted to block work on a bill to establish a trust fund to compensate asbestos victims.

''I don't think we are quite ready," Baucus said. ''I don't think we are ready to tackle this important and complex legislation at this time."

Sixty votes were needed for the Senate to take up the bill, but supporters could only muster 50 votes. Baucus joined 46 fellow Democrats in voting against the measure.

Sen. Conrad Burns, R-Mont., was one of the 50 senators who voted to allow the Senate to begin working on the bill, S 2290.

Three senators did not vote, and Sen. Zell Miller, Ga., was the lone Democrat to vote to begin work on the bill.

Senate Majority Leader Bill Frist, R-Tenn., and Minority Leader Tom Daschle, D-S.D., are saying work on the bill will continue behind the scenes. The bill has been stalled since last summer and significant differences are likely to hamper negotiations.

Libby residents who have asbestos-related diseases caused by a vermiculite mine run by the now-bankrupt W.R. Grace and Co. would be compensated under the measure, which would create a $124 billion fund.

Companies that manufactured or used asbestos and their insurers would have been required to contribute to the fund in exchange for being shielded from civil liability.

Baucus has worked hard to guarantee that the bill includes language requiring special treatment for Libby residents.

The bill would require the Labor Department to handle claims by people exposed to asbestos.

People would receive payments only if they meet specific medical criteria.

But Libby residents and former W.R. Grace workers would be exempted from medical criteria requirements. Their claims would go to a special medical advisory committee.

Baucus is trying to add a provision that would require the Labor Department to follow the medical advisory committee. He is concerned that the department will reject the committee's recommendation.

He also is trying to attach a provision that would automatically assume that all Libby victims had level-four exposure.

Under the bill, victims who had level-three exposure would receive $85,000, while victims who had level-four exposure would receive $400,000.

''Let me just emphasize that their situation for me and for them is especially unique," Baucus said. ''An entire town was poisoned with asbestos for decades by W.R. Grace, a company that lied to its workers. Lied to the community about the deadly dust it was exposing workers to. Lied to their families. Lied to the whole community. Hundreds of people have already died or become very sick. Hundreds more will likely follow."

Senate Judiciary Committee Chairman Orrin Hatch, R-Utah, who is leading the effort to pass the bill, promised to discuss the changes Baucus wanted, if Baucus supported the effort to take up the bill. Baucus responded by saying he would support taking up the bill, if Hatch agreed to his changes.

Hatch responded to Baucus by saying that the changes he is seeking are the type of issues that could be dealt with if the Senate worked on the bill.

''I believe we can accommodate Sen. Baucus so he can vote for the bill," Hatch said. ''I don't want to see the people of Libby, Montana, mistreated and frankly I believe we can make the change."

Burns agreed with Hatch's assessment and that is why he voted to allow the Senate to take up the bill.

''Let's move it," Burns said. ''We can't make it better until people get more earnest about it."

Democrats say the bill does not provide enough money to compensate asbestos victims. The Senate Judiciary Committee approved a bill, S 1125, last July that would have created a $153 billion fund. Republicans say Democrats are doing the bidding of trial lawyers, who stand to profit handsomely from the litigation.

''The trial lawyers have come in and exerted their influence," Burns said.

Despite Thursday's vote and the sharp differences that still exist, both Frist and Daschle said it was too early to write the bill's obituary.