Formula One leader Nico Rosberg took pole position for the Russian Grand Prix while Mercedes teammate Lewis Hamilton was 10th after a car failure ended his qualifying session early on Saturday.

Rosberg and Hamilton traded fastest times in the first two sessions, but their contest ended abruptly when Mercedes said Hamilton had a repeat of the power unit problem that left him at the back of the grid for the last race in China.

With Hamilton out of contention, Rosberg secured pole with ease, .706 seconds ahead of Ferrari's Sebastian Vettel, who faces a five-place grid penalty for Sunday's race due to a gearbox change.

Valtteri Bottas of Williams was third, 1.119 seconds behind Rosberg.

Rosberg can win his seventh race in succession and fourth of the season on Sunday.