SANTA CLARA, Calif. — The San Francisco 49ers signed free-agent defensive end Justin Smith today in a move they hope will bolster their pass rush.

Smith, the No. 4 overall pick by Cincinnati in 2001, had 43 1/2 sacks in seven seasons with the Bengals and was one of the top pass rushers available on the free agent market this season. His deal is reportedly for six years and is worth $45 million, including $20 million in guarantees.

After meeting with the 49ers coaching staff and taking a helicopter tour of San Francisco, Smith decided to cancel planned visits to Minnesota and Jacksonville and sign with the 49ers instead.

"The reason I decided to cancel my other visits is meeting with the coaching staff here," Smith said. "From top to bottom it's a first-class organization and when you get in a situation like that it's a no-brainer. I think I'll be a great fit."

The Niners were tied for 21st in the NFL last season with only 31 sacks. Bryant Young, who led the team with 6 1/2 sacks, retired after the season leaving a big void at end.

Smith had at least five sacks in each of his first six seasons with the Bengals before recording only two last season. He has led the Bengals defensive line in tackles in each of the past six seasons and was designated as the team's franchise player in 2007.

The Niners have been busy so far in the free agency season after going 5-11 last season, signing receiver Isaac Bruce and kick returner Allen Rossum.