Today 's Sears Tower renamed Willis Tower after London fashion company . Thousands join online group opposing building 's name change . Sears opened in 1973 with original tenants Sears Roebuck & Co .
Chicago 's Sears Tower renamed Willis Tower after London insurance broker . Thousands join online group opposing building 's name change . Landmark opened in 1973 with original tenant Sears Roebuck & Co .