Vacant Main Post Office building in Chicago may be sold again

CHICAGO (WLS) -- Chicago's vacant Main Post Office may be sold ... again.

Crain's Chicago Business reported Thursday that the owner of the Aon Center and Prudential Plaza has a contract to buy the building.

This comes as Mayor Rahm Emanuel has proposed seizing the former post office through eminent domain so it can be transferred to an owner who will develop the property.

The current owner purchased the building in 2009, but it remains vacant.

The building has been empty for more than 20 years.