The offensive guard's agent Leo Goeas told The Associated Press that his client had signed the deal at the team's headquarters in Orchard Park, and was traveling to report to camp in suburban Rochester. He missed only four practices after the Bills opened camp on Saturday.
Levitre is expected to receive a little more than $1.8 million in guarantees, and the four-year deal is worth more than $3.2 million, a source told ESPN.com's John Clayton.
The Bills confirmed the signing in a release.
The 51st overall pick out of Oregon State, Levitre made 39 starts and was first-team All-Pac 10 last year. The Bills are counting on Levitre to start at left guard as part of a completely retooled offensive line, which is also projected to feature unsigned first-round pick Eric Wood playing right guard.
In other Bills news, coach Dick Jauron said starting defensive tackle Marcus Stroud will miss up to a week with a strained left hamstring. Jauron and Stroud termed the injury as minor. Stroud was hurt during the second of Buffalo's two practices on Saturday.
The news is far worse for rookie running back Justice Hairston, who is expected to miss the rest of the season after hurting his knee minutes into the Bills' camp-opening practice on Saturday. Hairston signed with Buffalo as an undrafted free agent out of Central Connecticut.
John Clayton is a senior NFL writer for ESPN.com. The Associated Press contributed to this story.