Diversified real estate service firms continue to dominate management of commercial real estate properties. : You can also read our 2015 Top Property Managers, 2016 Top Property Managers and 2017 Top Property Managers rankings. Diversified real estate service firms continue to dominate management of commercial real estate properties. This year’s top four managers—JLL, Cushman & Wakefield, Colliers International and CBRE—now collectively manage nearly 13 billion square feet of commercial space, spread across office, multifamily, industrial, retail, healthcare and hospitality. Overall, institutional property managers have increased their portfolios steadily over the past three years.