Today's agreement comes two days after the team acquired him in a trade with Buffalo.
Walker will earn about two (m) million dollars this season, plus eight to nine (m) million dollars in bonuses, plus other incentives over the length of the contract.
Agent Albert Irby says his client likes being with the Bears and was anxious to get something done.
Buffalo obtained Walker from Philadelphia in March for linebacker Takeo Spikes and backup quarterback Kelly Holcomb. Walker refused to report to the Bills.
By acquiring Walker, the defending NFC champions filled a big hole that opened when the team released Tank Johnson following a series of run-ins with the law.