Vornado bought the Mart from the Kennedy family in 1998 for $630 million.
Joseph Kennedy, the father of president John F. Kennedy, bought it in 1945.
The Mart was the world's largest building before the Pentagon was completed.
Chicago's Merchandise Mart up for sale
September 4, 2010 (CHICAGO) Crain's Chicago Business reports Vornado Realty Trust wants to sell the two-block, 25-story building.
