S7 wins prestigious honour from National Geographic Traveler Awards 2015.
The two airlines begin codesharing on flights between Russia and Japan on Thursday.
Siberian carrier outperforms likes of British Airways, American Airlines and Air Canada in global list.
The airline - known for its Novosibirsk-based S7 brand - has been once of the success stories of Russian aviation in recent years.
A 15 million rouble subsidy has been granted to airline S7 to operate flights on the Moscow to Gorno-Altaisk route during the rest of 2012.
Last minute rescue bid to prevent Russia's second largest airline going bankrupt.
Flights just got more interesting with a 'meet and seat' e-scheme from Siberian airline S7.
Siberian airline tycoon - the Richard Branson of Russia - explains why he is stepping in to rescue stricken Transaero.
Siberian Natalia Fileva, 55, co-owner of S7 airline, perished alongside her father in private plane tragedy in Germany.