The Bears and Gase have reached a three-year agreement, Rapoport reports. Gase was previously offensive coordinator under new Bears coach John Fox while the pair was in Denver.
Gase replaces Aaron Kromer, who was fired along with head coach Marc Trestman at the end of the regular season.
Gase served as the Broncos' offensive coordinator for the last two seasons. Denver finished No. 1 and No. 2 in scoring offense in 2013 and 2014, respectively. The 2013 Broncos were the highest-scoring offense in NFL history.
Denver's offenses over the last two seasons were proficient running the ball, but with Peyton Manning under center, the Broncos emphasized passing. In 2013, Manning led the league in passing yards and set an NFL record with 55 touchdowns, while in 2014 Manning's 39 touchdowns were second in the league.
Gase reportedly interviewed for the head coaching jobs with the Broncos, San Francisco 49ers, Atlanta Falcons and Bears. He also reportedly interviewed for the Ravens' offensive coordinator position. Baltimore hired Trestman for that position on Wednesday.
Before Gase became the Broncos' offensive coordinator, he served two years as wide receiver coach and two years as quarterback coach with the Broncos.
The Bears finished 21st in total offense and 23rd in scoring offense in 2014.
- Stanley Kay