AUGUSTA, Maine — Former two-term independent Gov. Angus King is expected to end a week of speculation by announcing Monday whether he plans to run for the U.S. Senate seat.

A poll showed nearly two-thirds of Mainers view King favorably and that he would draw significant numbers of votes from Democratic and Republican challengers.

The announcement is scheduled for 7 p.m. at the Moulton Union building at Bowdoin College in Brunswick, where King lives.

King would not be the first independent to enter the race, but he is by far the biggest name and his decision dramatically reshapes the race for whomever the Republican and Democratic nominee turns out to be.

There has been speculation that independent Eliot Cutler may also join the race. He quelled that Monday with a statement he posted on Facebook in which he threw his support behind King.

“I have had several long conversations with Angus King during the past week, and I hope that he will run for the U.S. Senate,” Cutler said in a statement. “He would bring to the Senate the independence, the abilities, the reputation and the disposition that will make him a great Senator, that will serve us Mainers well and make us proud every day, and that will begin to rebuild and restore the Senate to what it was intended to be, the world’s greatest deliberative body.

“I hope that each and every one of you will join me in encouraging Angus to run and that you will join me in supporting him if he decides to do so.”

L. Sandy Maisel, professor of government at Colby College, said Cutler’s endorsement leads him to believe that King will enter the race.

“The logic of why King is announcing now is fascinating,” he said.

Does that make him the front-runner?

“I think it depends on how it shakes out on the two party sides,” Maisel said. “With him in, it becomes a very difficult race for a Republican or Democrat.”

At the moment, the Senate field is crowded but likely will settle by March 15, the deadline for signatures collected by party candidates to be submitted to the Secretary of State’s Office.

On the Democrats’ side, the leading candidates are U.S. Rep. Chellie Pingree, who appears likely to forgo re-election to her U.S. House seat representing Maine’s 1st Congressional District; and two-term governor and former U.S. House member John Baldacci. Neither has announced definitively that they are in the race but both are gathering signatures.

Former Secretary of State Matt Dunlap and state Sen. Cynthia Dill, D-Portland, are in the race as well, although Dill plans to run for the House if Pingree leaves that race.

On the Republicans’ side, a number of candidates have started gathering signatures. The biggest names are Secretary of State and former U.S. House candidate Charlie Summers, State Treasurer and 2010 gubernatorial candidate Bruce Poliquin, Maine Attorney General William Schneider, former state Senate President Rick Bennett, and Assistant Maine Senate Majority Leader Debra Plowman.

Scott D’Amboise also is in the race. He planned to challenge Snowe in the primary and has been largely overlooked by the GOP establishment, which doesn’t see him as a particularly strong candidate.

While party candidates are scrambling to gather 2,000 signatures before the March 15 deadline, King has more time. Independents must gather 4,000 signatures to get on the ballot for a U.S. Senate race but they have until June.

Maisel said if King is in the race, it hurts a Democratic candidate more than the Republican.

“If King’s not in and Pingree’s the [Democratic] nominee, she probably doesn’t lose,” he said. “A Republican could more easily win the seat with King in.”

A Public Policy Polling survey conducted over the weekend showed 62 percent of those polled thought favorably of King while 24 percent viewed him unfavorably. In a hypothetical three-way race among King, Summers and Pingree, King received 35 percent of Democratic votes, 25 percent of GOP votes and 53 percent of independent votes.

The full PPP poll on Maine’s now wide-open Senate race is expected to be released on Tuesday.

King, who turns 68 at the end of the month, is the oldest candidate to explore a run. He was Maine’s governor from 1995 to 2003. In November 1994, he narrowly won a three-way race against Republican Susan Collins, now a U.S. senator, and Democrat Joe Brennan of Portland, who had already served two terms as Maine’s governor from 1979 to 1987.

In 1998, King won re-election with 59 percent of the vote. Republican Jim Longley Jr., son of former Maine governor Jim Longley, received 19 percent and Democrat Tom Connolly received 12 percent.

During his re-election, King won broad support from Democrats and Republicans who found him more favorable than the party candidates.

He is perhaps best known for the Maine Learning Technology Initiative, a then-unprecedented idea to provide middle school students in Maine with laptops.