Russian carrier S7 Airlines is formally to join the Oneworld alliance in November, a move which will leave Star Alliance as the only major group without a member in the country.
S7 first disclosed that it was courting Oneworld in 2007 and last year began formalising partnerships ahead of full membership.
The carrier will become part of Oneworld from 15 November, connecting its frequent-flyer programme to those of the other alliance partners.
"It will enable us to offer our customers a truly global network served by partners who include some of the best-known and most-admired airlines in the world," says S7 chief Vladimir Obyedkov.
"It will also strengthen us financially, through revenues from passengers transferring to our network from our Oneworld partners and the cost reduction opportunities the alliance offers."
Oneworld member Royal Jordanian Airlines has revealed S7's joining date, and says the alliance's network will extend to another 55 destinations as a result.
"This will almost triple the number of destinations served by Oneworld in Russia, the CIS and other parts of East Europe," it adds.
S7 serves some 90 points include 45 destinations in Russia and around 25 in other CIS countries. Its main base is located at Moscow Domodedovo. The Russian carrier is working to link its IT systems to those of Oneworld's other members.
Oneworld managing partner John McCulloch says S7 will expand the alliance's network "substantially" in a region of increasing demand.
Russian flag-carrier Aeroflot is already a member of the SkyTeam alliance but Star Alliance has yet to secure a candidate.
Source: Air Transport Intelligence news
