The Chicago Bears announced Thursday that they have agreed to part ways with defensive coordinator Rod Marinelli. The Chicago Tribune reported that the Bears offered Marinelli a one-year extension through 2014. But sources say he left in loyalty to coach Lovie Smith, who was fired earlier this month. Also, the Bears announced that assistant coaches Mike Tice, Bob Babich, Jeremy Bates, Mike DeBord, Darryl Drake, Tim Holt and Tim Spencer will not be retained on new coach Marc Trestman's staff. Trestman was hired Tuesday from the Montreal Alouettes of the Canadian Football League, where he won two championships. Trestman also has hired New Orleans Saints interim head coach Aaron Kromer as offensive coordinator and offensive line coach and Dallas Cowboys special-teams coach Joe DeCamillis, who ESPN reported will be named assistant head coach.