TAM Airlines will join the Oneworld on March 31 next year when it will join sister carrier LAN in the alliance.
The news comes as LAN Colombia today also joined the British Airways-founded alliance.
TAM merged with LAN under the LATAM group last summer. One of the conditions of the merger was to consolidate under one alliance and the group then confirmed that this would be within Oneworld.
After TAM joins on March 31, all passenger airlines operated by the LATAM group will be part of Oneworld. TAM will leave Star Alliance on March 30.
Oneworld CEO Bruce Ashby today said: "As the leading airline in Latin America’s biggest economy, Brazil, TAM’s addition represents a significant landmark in Oneworld’s journey to establish itself as the first choice airline alliance for frequent international travellers the world over.”
TAM Airlines boss Claudia Sender added: "We want to introduce Brazil to our new partners and welcome them into our country. In the coming months, we will continue working to ensure a smooth transition for everyone.
“We also want our passengers to learn about the benefits, connections and products offered by Oneworld so they can travel the world with us.”
The airline said that members of its Fidelidade frequent flyer programme will maintain all points earned and their respective tier status.