Co-founder (with Robert Lurie), Equity Group Investments, LLC, Chicago, IL, 1968- ; this umbrella company oversaw three large real estate investment companies: Equity Residential, a huge real estate investment trust owning apartment buildings, Equity Office Properties, a REIT focused on office buildings and Equity Lifestyle, a mobile home company. In a prescient move, Zell sold his Equity Office Properties and its portfolio of 543 office buildings across the US to the Blackstone Group in 02/2007 for $39 billion. (See Terry Pristin, "Blackstone’s Bid for Equity Office Prevails,"Accessed 05/12/2011.) By 07/2007, Blackstone had sold 48% of the office buildings it had purchased or 261, returning about 70% of its original purchase price. (See Tom Royce, "Blackstone’s Flips Equity Office Properties At An Amazing Speed," 07/26/2007,Accessed 05/12/2011.)