While the Republicans can still filibuster, they are at a disadvantage during floor debate given the Democrats’ 59 to 41 majority. And the decision to allow floor debate appeared to be a significant retreat by the minority, reflecting a calculation that further delay was politically untenable.

Image The prime sponsor of the bill is Christopher Dodd, left. Harry Reid requested the consent of the Senate to move it forward. Credit... Doug Mills/The New York Times

Among the challenges for Republicans was explaining how they could participate in an oversight hearing on Tuesday criticizing Goldman Sachs executives and proclaiming the need to tighten regulation of Wall Street, but then go to the Senate chamber and vote to block debate of the financial regulatory bill.

In an uneasy appearance on Wednesday morning on the “Today” show on NBC, Senator Susan Collins, Republican of Maine, a centrist who is known for working across party lines, faced a series of tough questions on that issue. Later in the day, Ms. Collins was among the first Republicans to say it was time to open debate. “Negotiations have concluded,” she said. “It makes sense to proceed to the floor.”

The Republicans met late Wednesday afternoon to discuss the financial regulatory legislation and the steps ahead, and they defended their blocking maneuvers, saying it had helped secure assurances that changes would be made to the legislation, particularly in a chapter on liquidating failing companies.

Democrats, however, said that they had made no firm commitments other than to take up Republican concerns during floor debate, where amendments on any controversial issue typically require 60 votes to be approved.

In particular, Republicans said they had won the elimination of a proposed $50 billion fund that would be paid for by big financial companies and would be used to help pay for putting failed banks out of business.

The Obama administration also had opposed the fund, out of concern that it would complicate efforts to deal with more costly bank failures. And the Democrats had already indicated a willingness to remove the fund from the bill.