The Buffalo Bills checked one item off their season-ending to-do list today when they agreed to a three-year contract extension with defensive lineman Alan Branch.

Branch, who turns 29 Sunday when the Bills close out the regular season at New England, has started 12 games this year in his first season with the Bills.

"It feels good just knowing that my future is secure for a little bit. Not wondering what's going to be happening in the next couple of months, that's a load off, as well," he said this afternoon.

Branch, who's playing this season on a one-year, $3 million contract, started the year as a reserve along the defensive line. He became a starter after Alex Carrington was lost for the season because of an injury in Week Three. Terms of Branch's new deal have not yet been released

Branch, 6-foot-6 and 325 pounds, has 35 tackles this year as the "five technique" defensive end on the strong side -- where the tight end lines up.

"I was excited. I think that Alan has played extremely well for us," Bills coach Doug Marrone said. "We've been able to move him to that five-technique spot. He's made a lot of plays there. We have the ability to put him at nose. He's a big-body guy. When you look at our guys up front, and you look at the production of Kiko as our middle linebacker, a lot of that production goes because of the guys up front. They're taking up two blocks not letting anyone get on him, and Alan's done a great job with that, so we're happy to have him as part of this team as we go forward."

With Carrington also scheduled to become an unrestricted free agent, the Bills faced a big decision at the position. Branch's signing is one less offseason need.

"I like the fit a lot. I think schematically, this is one of the better defenses for me because I'm a quicker big fella. I can get penetration or I can surprise them with some power. I keep the offensive linemen on their toes most of the time. I feel like that goes toward my strengths a lot," he said. "When my agent and the team got everything settled, that was an easy decision for me to stay. Knowing that we're just a step away from putting everything together and becoming that playoff team that we know that we can be, I'm excited about being part of that building process."

The seventh-year veteran has started 46 of 93 career games and made 166 tackles and eight sacks. He spent the 2011-12 seasons with the Seattle Seahawks after entering the NFL as a second-round draft pick of Arizona in 2007.