A third airport in the Chicago region could attract new airlines to a market closed to them by airlines that hoard gates, Fitzgerald told the U.S. Senate commerce committee, which approved the bill 12-10.

Fitzgerald spokesman Brian Stoller said the bill would allow federal transportation officials to investigate whether airlines purposely hold gates at hub airports like O'Hare, or use them inefficiently to keep competitors out. Federal officials then would be allowed to "compel" airlines to release the gates.

In arguing for the bill, Fitzgerald said Congress shouldn't "let the airlines carve up the nation's aviation market like pieces of apple pie."

The bill now goes before the full Senate.