The most likely 60th vote is Sen. Olympia Snowe, R-Maine, but the statement from Sen. Reid's office implied that she had not as yet confirmed that she will support the bill.

Democrats need an additional Republican vote because of the death of Sen. Robert Byrd, D-W.Va. He died on June 28.

West Virginia's governor, Joe Manchin, has the authority to appoint a successor to serve until the next election in November 2011, but is considering asking the state legislature to hold a vote this fall because he is considering running for the post.

Several banking and insurance lobbyists responded by saying that while the timing remains up in the air, "This legislation will pass the Senate and become law within a reasonable period."

Another potential supporter, Sen. Charles Grassley, R-Iowa, is balking because unexpended Troubled Asset Relief Program funds, as well as an additional levy on banks through the Federal Deposit Insurance Corporation, would be used to fund the bill.

Sen. Grassley supported the original Senate bill.

In a statement, Sen. Brown said he has made the decision to support the bill after studying it over the Independence Day recess.

"I appreciate the efforts to improve the bill, especially the removal of the $19 billion bank tax," he said.

As a result, he said, "it is a better bill than it was when this whole process started. While it isn't perfect, I expect to support the bill when it comes up for a vote."

The bill is H.R. 4173, the Dodd-Frank Wall Street Reform and Consumer Protection Act.

The bill passed the House June 30 by a vote of 237-192.

The bill creates for the first time a Federal Insurance Office, and gives a new Systemic Risk Council the authority to monitor insurance companies considered a systemic risk to the system.

The legislation also contains a provision to modernize and streamline the surplus lines and non-admitted market.