Following the merger of the two airlines in 2004, the French flag carrier Air France, which was founded in 1933 and is based in Tremblay-en-France, is now owned and run by Air France-KLM. The Franco-Dutch corporation runs a number of airlines in addition to Air France flights that travel to 168 locations worldwide and 36 cities in France. Travelers can use the Air France online reservation system's "Time to consider" function, which holds the reservation for up to 3 days at the same fee. With regard to both passenger volume and revenue production, Air France-KLM is one of the biggest airline alliances in the world.