Illinois Gov. Pat Quinn signed a measure Thursday that will allow the Illinois Department of Transportation (IDOT) to execute public-private contracts for the financing, construction and operations of a third regional airport for greater Metropolitan Chicago.

The legislation allows IDOT to proceed with the purchase of $70 million of land for the airport, to be sited near the far south suburb of Peotone. The Chicago area currently is served by two airports, O'Hare International on the city's northwest side and Midway on its southwest side.

Quinn says a third airport would satisfy growing demand for air service in the region.“This part of our state, if was one city, would be one of the largest cities in America, and that's why we need a south suburban airport to deal with the cargo that comes in from all over the world, all over the country,” Quinn said in a statement on Thursday.

The Federal Aviation Authority (FAA) has granted site approval for a potential airport, but is awaiting a master plan from the state before deciding whether to allow the project to proceed.

Assuming plans are approved, it is unclear whether major airlines would agree to operate at the facility. Some airlines have openly opposed the project, indicating it would undermine expansion plans for O'Hare.

Former White House chief of staff Bill Daley, who is vying for the governorship in next year's Democratic primary, questioned whether the state has the borrowing capacity to fund a new airport, given its poor credit rating.

“Every election cycle we get somebody dangling this airport thing that somebody else is going to pay for – and allegedly not the taxpayers of Illinois – that I think often times has been a cruel hoax on people,” Daley told reporters on Thursday.