Chicago could be back on the map for airport.
Birmingham Airport and Chicago O'Hare International Airport have become sister airports to "commit to the development of new opportunities", particularly the reinstatement of direct flights between the cities.
Bosses from Birmingham Airport and the Chicago Department of Aviation - operator of Chicago O'Hare International - have signed a memorandum of understanding, agreeing to work together to strengthen trade, tourism and cultural links between the two cities.
Speaking at O'Hare, Birmingham Airport chief executive, Paul Kehoe, said: "Birmingham enjoys a special relationship with Chicago as the two cities have been twinned since 1993.
"More than 350 North American companies, including Microsoft, Motorola and Kraft Foods - which has its headquarters in Chicago - provide employment for 60,000 people in the area.
"This formal partnership will show industry that we're committed to strengthening links further and pushing for the reinstatement of direct flights."
Chicago Department of Aviation commissioner, Rosemarie Andolino, said: "On behalf of Chicago Mayor Rahm Emanuel, the city of Chicago and the Chicago Department of Aviation, we are very pleased to establish this new partnership with Birmingham Airport.''