The city of St. Louis has submitted a preliminary application to the Federal Aviation Administration’s Airport Privatization Pilot Program, which could allow it to privatize operations of St. Louis Lambert International Airport.

A 1997 federal law, which was reauthorized in 2012, allows up to 10 public airports to lease the facilities to private operators. Five airports are currently approved, and city officials said they did not know how many airports are competing for the remaining five slots.

Mayor Francis Slay said in an interview Wednesday that the move could free up millions of dollars more from the airport, perhaps helping the city invest in projects like a north-south MetroLink expansion. The city, which owns the airport, currently receives about $6 million from the facility per current law, he said. Travis Brown of Grow Missouri Inc., which is partnering with the city on the project, said that figure could increase by four to 10 times under a public-private partnership. Grow Missouri Inc. is a nonprofit funded by billionaire investor and activist Rex Sinquefield.

The extra money, to the city and for upgrades at the airport, would come from the private operator, which would enter a long-term lease agreement with the city.

“This would allow us to avoid that restriction on using airport funds for municipal purposes,” Slay said.

The lease could dictate what upgrades are made and outline other parameters, such as how much the operator could increase fees, Slay said.

Slay’s office has partnered with Grow Missouri Inc. in the planning process. Grow Missouri has agreed to cover the costs of hiring legal and financial professionals to work on the process, the city said.

If St. Louis is accepted in the program, it could take well over a year to make the change, Slay said, and the city, airlines and the FAA would have to sign off.

“The whole idea behind this is to give us the opportunity to explore big and better things for the airport,” Slay said, adding that it has weathered tough times, with a $1 billion runway that isn’t used because American Airlines “dehubbed” here. “It could mean improving opportunities for cargo, but also making the airport a better place with better connecting flights.”