The
Aon Center (200 East
Randolph Street, formerly
Amoco Building) is a modern supertall skyscraper in the
Chicago Loop,
Chicago,
Illinois,
United States, designed by architect firms
Edward Durell Stone and The
Perkins and Will partnership, and completed in 1974 as the
Standard Oil Building. With 83 floors and a height of 1,136 feet (346 m), it is the third tallest building in Chicago, surpassed in height by the
Willis Tower and the
Trump International Hotel and Tower. The building is managed by
Jones Lang LaSalle, which is also headquartered in the building. Aon Center formerly had the headquarters of
Aon and
Amoco; Aon's US operations are still headquartered here.