American Airlines and LAN Colombia will launch their codeshare agreement from 1 August, with travel starting from 8 August.
The two airlines first announced last year their intentions to codeshare.
Under the agreement, the two carriers will codeshare on flights between the USA and Colombia. American's passengers will get access to four new Colombian destinations: Barranquilla, Bucaramanga, Cartagena and Pereira. In return, LAN Colombia's travellers will receive access to 12 new destinations in the USA on American's network.
LAN Colombia is the Bogota-based subsidiary of Chile-based LAN. Both LAN and American are already Oneworld members, and LAN Colombia will join the alliance from the fourth quarter of 2013.