The two sides had until Monday afternoon to reach a long-term deal or Forte would have had to accept a one-year franchise offer of $7.74 million for the 2012 season. There had been speculation that lack of a multiyear deal could have prompted Forte to hold out during training camp.
"I'm proud to be a Chicago Bear and excited to be here for another four years," Forte said. "I'd like to thank my family, my agent and the Chicago Bears. I've been working hard this off-season and am looking forward to joining my teammates at training camp next week. I'm glad the business part is done and we can all turn our attention to football and our goal of winning a championship."
Forte, 26, had a Pro Bowl season in 2011, rushing for 997 yards and three touchdowns, and catching 52 passes for 490 yards and a score.
But he missed the last four games of the season with a right knee injury.
In four NFL seasons, he has 4,233 rushing yards and 1,985 receiving yards with 29 touchdowns.