The airline is moving out of its Chicago terminal.
Allegiant Airlines will depart Chicago’s Midway Airport next month.
The move comes after Allegiant’s bid for a new lease at Midway was rejected by the Illinois Department of Aviation in April, according to the Chicago Tribune.
The Chicago Tribune reported the lease agreement was for two years, but Allegiant is currently seeking a five-year lease, which would have been more lucrative.
The new lease will take effect on Sept. 1.
The airport is owned by the Chicago Aviation Authority, a private nonprofit organization that is in charge of the airport.
In February, the Chicago airport was awarded a $7.5 million contract from the Federal Aviation Administration, which is the U.S. government agency that provides oversight of the airline industry.
Allegiance has been a key player in the airline business for decades.
It owns the Chicago-to-Los Angeles, Chicago-New York, Chicago to Seattle and Chicago-Detroit routes.
In December, the company announced it would begin leasing new flights to Hawaii, but it has yet to announce an exact date for the first flights.
The airline had been operating under the AirBnB brand, but the company pulled that name in May after allegations of sexual harassment surfaced.
The company has been criticized for its low rates for tickets and baggage, and it has been hit by numerous lawsuits in the past decade, including the case of a man who said he was sexually assaulted by the airline employee.