Associated Press - March 8, 2010 2:14 PM ET

LITTLE ROCK, Ark. (AP) - The filing period for state and federal office in Arkansas has ended and the stage is set for heated primaries in the United States Senate race.

4 of the eight Republicans running for the GOP nomination were among the last to file by the noon Monday deadline. Randy Alexander, Gilbert Baker, Jim Holt and Conrad Reynolds made their candidacies official by filing at the state Capitol.

The race for the seat held by Sen. Blanche Lincoln is shaping up to be an expensive battle with Lincoln trying to hold off a challenge from Lt. Gov. Bill Halter in the Democratic primary. D.C. Morrison of Little Rock also filed for the Democratic nomination.

Secretary of State Charlie Daniels says 338 people have filed to run for office over the past week.

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