Together with the Renaissance Center, they form the city's distinctive skyline.
The building was razed in 1973 to make way to construct the Renaissance Center.
In the ensuing years, the Renaissance Center would face competition from the growing suburban office market.
The identity of other potential buyers for the Renaissance Center could not be learned.
Many have been there since the Renaissance Center opened.
Detroit has just under 11 million square feet of office space in the 26 buildings usually surveyed, including the Renaissance Center.
He was the first director of the university's Renaissance Centre, opened in 1984.
Since retirement he has continued to provide lectures at the Renaissance Centre.
Ford had a lease through 2005 on one 39-story tower and part of another at the Renaissance Center.
The Renaissance Center cost $350 million to build nearly two decades ago.