Chicago-based law firm Greenberg Traurig has signed an agreement to move its headquarters from 77 W. Wacker Drive to a new development under construction in the Fulton Market neighborhood.... The move continues the exodus of tenants from downtown Chicago as companies seek out new office buildings that provide better amenities and are more likely to entice employees back to the workplace. The global firm will occupy 90, 000 square feet in 360 N. Green St., a 24-story tower that developer Sterlin