FACTBOX-Key players in final hurdle for Wall St bill

July 10 (Reuters) - Democrats hoping to pass a landmark overhaul of financial regulations will likely need to win over at least three Republicans in the Senate if they wish to send the measure to President Barack Obama by mid-July.

Democrats had hoped to get a quick replacement for late Senator Robert Byrd, but they could be waiting for some time as state officials sort out their election laws.

Right now, Senate backers of financial reform have not yet nailed down the 60 votes required to advance legislation in the 100-seat chamber.

Here are the lawmakers and other officials whose support -- or lack thereof -- will loom large before the Senate votes on the measure.

WEST VIRGINIA GOVERNOR JOE MANCHIN

Manchin, a Democrat, is expected to name a Democrat who backs the financial-reform bill to temporarily fill Byrd's seat. But he might wait until he and other state officials have decided when to hold an election to fill the seat permanently.

Manchin is interested in running for the seat but has said he would not appoint himself as interim senator.

REPUBLICAN SENATOR SCOTT BROWN

A moderate elected in January to fill the seat of the late Edward Kennedy, Brown previously supported the bill on the Senate floor and won significant carve-outs for mutual funds, insurers and other industry players in his home state of Massachusetts.

Brown had complained that a final version of the bill contained a $17.9 billion bank tax and said he was pleased when congressional negotiators subsequently stripped it out.

"I'm going to be making a decision soon, but I'm liking what I see," Brown said on Sunday, according to the website of WHDH television.

A spokeswoman said Brown would probably not make an official announcement this week.

REPUBLICAN SENATOR OLYMPIA SNOWE

Snowe, another New England moderate from Maine, also previously supported the bill on the Senate floor and had been successful in easing its impact on small businesses. Like Brown, she objected to the bank tax and said she was pleased it was removed.

Snowe said on Saturday she was still studying the measure.

"It's a big issue, and the most important thing is to make sure we get it right," Snowe told Reuters when asked if recent changes to the legislation had secured her support.

REPUBLICAN SENATOR SUSAN COLLINS

Another moderate Republican from Maine, Collins is responsible for the portion of the bill that would require larger financial firms to boost their capital reserves. Collins, a former state banking regulator, previously backed the bill on the Senate floor and said she is likely to support it now that the bank tax has been dropped.

"On balance, based on my initial review of the conference report, I am inclined to support it," she told reporters on June 30.

REPUBLICAN SENATOR CHARLES GRASSLEY

Grassley's support of the bill has been less consistent than the other Republicans mentioned here. He was the lone member of his party to vote for tough derivatives regulations drafted by the Agriculture Committee, and he voted for final passage on the Senate floor. But he had voted against it in an earlier procedural vote. Spokeswoman Jill Kozeny said he is "very concerned" that the bill covers its costs by raising deposit-insurance fees and tapping a bank-bailout fund.

DEMOCRATIC SENATOR RUSSELL FEINGOLD

One of the most liberal members of the Senate, Feingold has said the bill does not do enough to prevent future crises and he voted against it on the Senate floor. His position remains unchanged, though he said the final version contains some improvements. (Reporting by Andy Sullivan and Corbett B. Daly; Editing by Cynthia Osterman, Chizu Nomiyama and Leslie Adler)