Of the 16, the city said seven were deemed capable of operating Midway, the nation's 26th-busiest airport.
The Chicago Tribune reported Saturday the seven viable investment groups included ACO Investment Group, which has experience operating airports; AMP Capital Investors Limited, which operates airports in Britain and Australia; and Corporation America Group, which manages 49 airports and is based in Argentina.
Chicago's previous attempt to privatize Midway collapsed in 2009 due to the financial crisis.
That attempt involved a 99-year lease. In the meantime, a 75-year agreement on operating Chicago's parking meters -- signed during former Mayor Richard Daley's tenure -- was widely panned after parking meter rates jumped, the Tribune said.
As a consequence, Mayor Rahm Emanuel has said he does not want to over-commit to a risky privatization plan. His administration said it would limit the lease for Midway to 40 years and work with a revenue-sharing agreement, rather than an upfront payment.
The lease would include plans for paying down Midway's $1.4 billion debt, incurred during an airport upgrade in 1996.