MANCHESTER, N.H. (Reuters) - Democratic presidential contender John Kerry holds a shrinking three-point lead over Howard Dean on the eve of the New Hampshire primary, according to a Reuters/MSNBC/Zogby poll released Monday.

Dean shaved four points off Kerry's advantage in the latest three-day tracking poll, as supporters who wavered after his dismal third-place Iowa finish and screaming concession speech appeared to be returning to the fold.

Kerry led Dean 31 percent to 28 percent in the new poll, with John Edwards jumping three points to narrowly trail Wesley Clark for third place, 13 percent to 12 percent. Connecticut Sen. Joseph Lieberman remained static at 9 percent.

"There is no question that the race has tightened up," pollster John Zogby said. "Dean stopped the bleeding in the middle of the week and he has slowly regained some of the support he had lost."

Dean's favorable ratings crept back up this week but almost half of likely New Hampshire voters still think it is unlikely he can beat President Bush -- a crucial issue as Democrats look ahead to November's general election.

"There are some serious doubts about whether he can beat President Bush," Zogby said of Dean, who gained five points in the new poll while Kerry gained one point and Edwards jumped three points. The other candidates stayed level.

A tracking poll combines the results of three consecutive nights of polling, then drops the first night's results each time a new night is added. It allows pollsters to record shifts in voter sentiment as they happen.

The New Hampshire primary has seen many late momentum swings and surprise showings through history, sometimes fueled by the state's large bloc of independent voters, who can cast ballots in either the Democratic or Republican primary and traditionally decide late.

In Monday's poll, undecideds who were leaning toward one candidate were factored into the totals, leaving three percent undecided. Without factoring the leaners in the totals, 13 percent of likely New Hampshire voters remain undecided.

Other polls have shown Kerry with a much wider lead.

Kerry, a senator from neighboring Massachusetts, rolled to his lead in New Hampshire this week after a surprising comeback win in Iowa's caucuses that gave his campaign a huge jolt of momentum.

Late last month Dean, the former governor of neighboring Vermont, led polls in New Hampshire by more than 20 points, but much of his lead evaporated in the week before Iowa and quickly disappeared after his loss there.

Clark, the retired general and former NATO commander, is trying to hold third place despite a charge from Edwards, the North Carolina senator who finished a strong second in Iowa.

The poll of 601 likely primary voters was taken Friday through Sunday and has a margin of error of 4.1 percentage points. The final poll will be released Tuesday, the day of the New Hampshire primary.

Ohio Rep. Dennis Kucinich received 2 percent in the poll, with civil rights activist Al Sharpton getting 1 percent.