Russia's S7 Airlines has formally become a member of the Oneworld alliance, while subsidiary Globus is also joining as an affiliate.
Inclusion of the two operations brings 55 destinations in Russia and the former Soviet states, among the 90 points they serve, to the Oneworld network.
As a result the network has expanded to more than 780 cities.
"Oneworld gives S7 the best-quality partners, the best worldwide network, the best alliance services for our customers and the best opportunity to put our airline firmly on the global stage," said S7 Group chief Vladislav Filev, speaking at an event in Moscow today.
Oneworld managing partner John McCulloch states that S7 gives the alliance access to a "key region" and is a carrier which "matches our demanding quality requirements".
The alliance adds: "S7's addition to the alliance completes what has been one of the biggest projects in the airline's history, with working groups covering some 35 streams of activity."
British Airways has been S7's sponsor during the accession. Chief executive Willie Walsh describes S7 as "the best [carrier], we firmly believe, in Russia and the CIS".
Oneworld's network will increase to more than 900 points once India's Kingfisher Airlines and Germany's Air Berlin join in the next 18 months.
Source: Air Transport Intelligence news
