Senator Lisa Murkowski wins Alaska write-in campaign

ANCHORAGE (Reuters) - Alaska Republican Lisa Murkowski Wednesday became the first Senator in more than 50 years to win an election with a write-in campaign as she established an unassailable lead over conservative Tea Party movement favorite Joe Miller.

The result of the last undecided race of the November 2 congressional elections does not alter the make-up of the Senate, where Republicans picked up six seats in a broad triumph over Democrats.

Murkowski had a lead of about 10,000 votes with only 752 ballots left to be counted, a state election official said on Wednesday. According to the latest figures from the state's division of elections, Murkowski has 100,868 votes to Miller's 90,468.

Murkowski is set to address her supporters in Anchorage on Wednesday evening. Miller has not conceded the election, which may yet be drawn out by legal challenges.

A member of one of the state's most powerful political families and a senator since 2002, Murkowski had to campaign to get voters to write her name on the ballot after Miller, backed by former Alaska Governor Sarah Palin, defeated her in Alaska's Republican primary campaign in August.

The last senator to win a write-in campaign -- where voters write in the name of a chosen candidate instead of selecting a printed name on the ballot -- was then-Democrat Strom Thurmond in South Carolina in 1954.

The Miller campaign is challenging thousands of Murkowski's write-in votes, on grounds of misspelling or procedural errors, but even subtracting those challenged votes, Murkowski still has 92,715 votes, an unassailable lead over Miller, with only 752 ballots left to be counted. Wednesday is the deadline for overseas absentee ballots to count but few are expected.

The Democratic candidate, Scott McAdams, was a distant third with 59,817 votes at the latest count.

(Additional reporting by Steve Holland and Bill Rigby; Editing by Bill Trott and Cynthia Osterman)