The Bears on Wednesday bolstered their defense with one of the NFL's most prolific pass rushers, agreeing to terms with defensive end Jared Allen on a four-year contract.

The 6-6, 265-pounder has recorded 128.5 sacks in 10 NFL seasons with the Chiefs (2004-07) and Vikings (2008-13), the most by any player since he entered the league and the 12th most in history.

Five-time Pro Bowl defensive end Jared Allen sacks Packers quarterback Aaron Rodgers.

"We are extremely happy for Jared, his wife Amy, our fans and the Chicago Bears that Jared has agreed to terms and will be joining the Bears family," said general manager Phil Emery. "This is another important step in our continued efforts to build our team towards a championship level."

Allen led the NFL in sacks in 2007 and 2011, when he recorded 22, just half a sack shy of Michael Strahan's single-season league record. That total included 3.5 sacks of Bears quarterback Josh McCown in the season finale in Minnesota.  

A five-time Pro Bowler who has been voted first-team All Pro four times, Allen has averaged 14.5 sacks over the past seven seasons, never registering fewer than 11 during that span. In 2013, Allen compiled 11.5 sacks, 52 tackles, 13 tackles-for-loss, six pass deflections and two forced fumbles.

Allen has also been extremely durable, starting all 16 games each of the past six years and never playing in fewer than 14 games in any season since entering the NFL. In 157 career games, Allen has also compiled 558 tackles, five interceptions, 29 forced fumbles, 17 fumble recoveries, 51 pass deflections and four safeties, tied for the most in NFL history.

"We're really excited about adding Jared to our football team," said coach Marc Trestman. "We know what his abilities bring to the table. Jared is certainly a very experienced player in the league. We believe he's going to come in hungry and excited to be part of our football team, and we believe he'll fit right in with the other new players that we've added and the guys that are

already on the defensive side of the ball. I know that our defensive coaches are excited as well."

Allen, who will turn 32 on April 3, was selected by the Chiefs in the fourth round of the 2004 draft out of Idaho State. He was traded to the Vikings on April 22, 2008 in exchange for a first-round pick, two third-round picks and a swap of sixth-round selections.

In 2009, Allen set a career high with 4.5 sacks against the Packers and scored the first defensive touchdown of his career by returning a fumble 52 yards versus the Rams. He also joined Reggie White as the only NFL players to record at least 14.5 sacks in three straight seasons (2007-09).

After allowing the most points, yards and rushing yards in franchise history while also tying for last in the NFL in sacks in 2013, the Bears have completely revamped their defense. Allen is the fourth defensive end they've signed since the start of free agency March 11, following Lamarr Houston (Raiders), Willie Young (Lions) and Israel Idonije (Lions).

Many NFL analysts expected Allen to sign with the Seahawks after he had made two free-agent visits to Seattle, but he ultimately decided to join the Bears.