Democrat keeps key Senate seat in Colorado: paper

WASHINGTON (Reuters) - Democratic Senator Michael Bennet held on to his seat in Colorado after a tough challenge by the Tea Party-backed Republican Ken Buck, the Denver Post projected on Wednesday.

The race between Bennet and Buck, a former prosecutor, was neck-and-neck in the state, where voters had said the struggling economy was the biggest issue.

Buck, a favorite among the conservative Tea Party movement, repeatedly criticized Bennet for his support of President Barack Obama's healthcare overhaul law, the economic stimulus package, and auto industry bailouts.

Bennet, a former Denver public school superintendent, was appointed to the Senate seat last year to replace Ken Salazar, who became Interior Secretary.

(Reporting by Jeremy Pelofsky; Editing by Frances Kerry and Leslie Adler)