The Airbus A330 Multi Role Tanker Transport (MRTT) is a European aerial refueling and military transport aircraft based on the civilian Airbus A330. A total of 17 countries have placed firm orders for approximately 85 aircraft, of which 66 have been delivered. A version of the A330 MRTT, the EADS/Northrop Grumman KC-45, was selected by the United States Air Force for its aerial tanker replacement program, but lost when the program was rebid. According to Airbus, the A330 MRTT has more than 90% of the air-to-air refueling aircraft market share outside the United States.