Chicago has taken another step toward leasing its Midway Airport by filing a preliminary application with the Federal Aviation Administration to participate in a pilot program for selling or leasing airports.

City officials said late on Thursday that the move was just one of many steps the city will take over the next several months as it pursues a long-term lease with a private operator.

The FAA's pilot program allows for participation by up to five airports, with only one being a major commercial hub airport -- which Chicago is pursuing, the officials said.

Final approval by the FAA and by airlines operating at Midway was needed to complete any lease deal, and the city has no specific timetable set, they added.

Chicago's application was only the third received for the FAA's pilot program with Midway being the only hub to apply so far, said Marcia Adams, a FAA spokeswoman. She added the FAA will undertake a preliminary review of Chicago's application within 30 days.

As part of any potential agreement with a private operator to manage Midway Airport, the Federal Transportation Security Administration would maintain responsibility for passenger and baggage screening at the airport, supervision and oversight of the airport's security program, and ensuring airline compliance with all federal security regulations, according to the city.

The Chicago Police Department would continue law enforcement activities and the Chicago Fire Department would still have responsibility for fire, medical, and other airport emergencies.

"Any agreement to lease the airport will outline and ensure that Midway's best practices in terms of safety and security, airport operations and customer service remain in effect," Chicago Aviation Commissioner Nuria Fernandez said in a statement.

Earlier this year, Chicago assembled a legal and financing team to explore a Midway lease. The city gained USD$1.83 billion in 2005 from a 99 year lease for its Skyway toll bridge and is in the process of seeking qualified bidders for four parking garages.

Under a state law that opened the door to an airport lease, most of the net proceeds would be used for new capital projects or pension contributions. In May, Chicago Chief Financial Officer Dana Levenson warned of falling funding ratios for the city's four employee pension funds.