After just a week, multi-millionaire businessman Fred Lampropoulos plans to drop his challenge of U.S. Sen. Bob Bennett, Republican sources told The Salt Lake Tribune.

Lampropoulos, the chairman and CEO of medical device maufacturer Merit Medical, has business commitments that prevent him from seeking the GOP nomination, sources familiar with the decision said Wednesday.

Lampropoulos was scheduled to participate in a White House Forum on Jobs and Economic Growth in Washington, D.C., on Thursday.

The South Jordan businessman joined the race last week, stepping into a vacuum created when Attorney General Mark Shurtleff dropped out, citing the need to tend to his daughter's health problems. Shurtleff had been viewed as the front runner among several Republican challengers to Bennett.

Lampropoulos, who spent about $1.6 million of his own money on an unsuccessful bid for governor in 2004, brought to the race deep pockets and the potential to compete with Bennett's healthy fundraising advantage.

Before joining the race, Lampropoulos was a prominent Bennett supporter, hosting fundraisers for the three-term senator.

A poll conducted by KSL and The Deseret News found that Lampropoulos was in the middle of a crowded field of Bennett's challengers, drawing about 4 percent of the public support, even with businessman Tim Bridgewater, and a point behind Cherilyn Eagar. Twenty-seven percent favored Bennett's re-election.

In an interview last Tuesday, Lampropoulos told The Tribune he decided to run because he was worried about the direction of the country, and was pushed over the line because of a proposed tax on medical devices that is in the health reform legislation pending in Congress.

"We provide all these jobs and spend $10 million to $15 million a year on research and development," Lampropoulos said. "To be singled out in such a discriminatory manner because of the field we're in is outrageous."