The AW139 was originally designed and developed jointly by Agusta and Bell Helicopters and marketed as the Agusta-Bell AB139, being redesignated AW139 when Bell withdrew from the project.
Orixinalmente o AW139 foi deseñado e desenvolvido conxuntamente entre Agusta e Bell Helicopter e comercializado como o Agusta-Bell AB139, recibindo o nome AW139 cando Bell retirouse do proxecto.