Senator Olympia J. Snowe, Republican of Maine, said Monday that she was prepared to support the final version of legislation to overhaul the nation’s financial regulatory system, putting the Senate in a position to complete the bill by week’s end.

Earlier on Monday, Senator Scott Brown, Republican of Massachusetts, said that he, too, was ready to approve the bill after pondering it over the Fourth of July recess.

Senate Democrats need the backing of at least three Republicans in order to advance the financial regulatory overhaul. Party leaders had thought they might need to wait until next week for Gov. Joe Manchin III of West Virginia to name a replacement for the late Senator Robert C. Byrd, who had supported the bill.

But with Senator Susan Collins, Republican of Maine, already indicated her intention to support the measure, the announcements by Ms. Snowe and Mr. Brown made clear that Democrats would have the 60 votes needed to close debate and move to a final vote.

Senator Charles E. Grassley, Republican of Iowa, had supported the earlier Senate version of the legislation but has not said how he would vote. Mr. Grassley has said he is concerned about some of the ways Democrats have proposed to pay for $20 billion in administrative costs for the regulatory bill.

Mr. Grassley voted in favor of the Troubled Asset Relief Program to rescue the financial system in October 2008, but against the economic stimulus measure. His aides have said that he has ongoing concerns about the way the TARP program was administered, and that he did not like the idea of using spending authority freed up by ending the TARP early to help pay for the regulatory overhaul. Mr. Grassley has said that any money left over from the TARP should be used to reduce the deficit.

In her statement, Ms. Snowe said the regulatory bill would help prevent future economic crises.

“To ensure we avoid another financial catastrophe such as the one that plunged our nation into the worst recession since the Great Depression, it is imperative that we implement an aggressive overhaul of the American financial regulatory system,” she said. “And this effort must include real and substantial consequences for those whose reckless actions caused the crisis in the first place while guaranteeing the transparency and accountability of taxpayer dollars. After thoroughly reviewing the 2,315-page financial regulatory reform conference bill during the July 4 work period, I intend to support passage of the legislation when it’s brought before the Senate for consideration.”

Anticipating a delay, the Senate majority leader, Harry Reid of Nevada, had planned to work on a bill to bolster lending, and provide tax breaks, to small businesses.

Under normal Senate procedure, it would probably take until Thursday to hold a final vote on the financial regulatory bill, unless Senate Republican leaders agree to allow a vote to happen sooner.