Presidential hopeful and former Massachusetts governor Mitt Romney won Saturday's Republican primary election in the northeastern state of Maine, the Republican Party said.
With 57 per cent of votes counted, Romney took 52 per cent, followed by the national frontrunner, Arizona Senator John McCain with 22 per cent, Ron Paul with 19 per cent and Mike Huckabee 5 per cent.
"With those results it is very sure that former governor Romney wins the contest," Maine Republican Party vice chair Scott Kauffman told AFP.
Although the Maine primary carries little weight in the national nominating contest, it does provide a symbolic boost for the conservative candidate in his attempt to overtake McCain in national opinion polls ahead of the key "Super Tuesday" event when more than 20 states are at stake.
"Today the people of Maine joined those from across the nation in casting their vote for conservative change in Washington," Romney, 60, said after the results were announced.
The Maine primary elects delegates to the state convention in May, which in turn will name delegates to the Republican national convention in September to choose the candidate.
Maine's Republican primary, however, is non-binding, with the 21 chosen delegates free to vote for whomever they chose at the state convention.
The Democratic Party will hold its primary in Maine on February 10.