A diesel mechanic has settled his lawsuit against Union Pacific Railroad Co. for $6.1 million seven years after he sustained lower back and groin injuries when he slipped while working at a rail yard.The settlement agreement was reached in November after a series of post-trial motions and an unpublished 1st District Appellate Court opinion, according to plaintiffs’ attorney Christopher M. Norem of Parente & Norem P.C.In February 2017, Cook County jurors awarded $5.4 million to plaintiff Andreas Bakopoulos in his …