CHICAGO — GE Transportation, a unit of General Electric Co., will move its headquarters from Erie to 500 W. Monroe in Chicago. The company will occupy 53,972 square feet of space on the 23rd and 24th floors at the building. 500 W. Monroe is a 1 million-square-foot office tower in the city's West Loop. Steve Smith, Gary Kostecki and Brad Despot of Jones Lang LaSalle represented the building owner, Piedmont Office Realty Trust, in the transaction. Jeff Samaras of Cushman & Wakefield represented the tenant.