Sri Lankan Airlines will become a Oneworld member in early 2014, it has been announced.
The carrier became a member elect of the alliance last year (see news, June 2012).
It will be supported through the alliance implementation programme by its sponsor, Cathay Pacific.
Sri Lankan already maintains a code-sharing partnership with another Oneworld member, Malaysia Airlines, and has also announced similar agreements with Royal Jordanian and S7 Airlines.
The flag carrier has seen a significant growth since peace returned to Sri Lanka three years ago.
It now operates a fleet of 21 aircraft from its Colombo base and flies to 34 destinations in 22 countries across Asia, Europe and the Middle East, including the Oneworld hubs of London Heathrow, Hong Kong, Kuala Lumpur and Tokyo Narita.
Sri Lankan's entry into Oneworld will bring three new destinations to the network - Kochi, Tiruchirappalli and Thiruvananthapuram, all of which are in Southern India and will expand the alliance's global coverage to 860 destinations in more than 150 countries.
The airline' chairman Nishantha Wickremasinghe said: "Joining the alliance will help put SriLankan more firmly on the global aviation map and vastly improve Sri Lanka's connections with the rest of the world, with all that means for our country's vital tourism industry."
The entry also means that customers of Sri Lankan's frequent flyer programme FlySmiLes will be able to earn and redeem awards when flying with any Oneworld carrier. In addition, top-tier members will be able to use any of the group's 550-plus airport lounges.
Similarly, the 120 million frequent flyer members of Oneworld's established airlines will be able to earn and redeem rewards when flying on Sri Lankan flights.