Officials in Chicago said 16 investor groups have submitted request for qualifications applications to take over operation of Midway Airport.
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.