Sebastian Vettel fastest in third practice

Red Bull's Sebastian Vettel has finished the fastest in the third and final practice session ahead of the Korean Grand Prix.

The German edged out McLaren's Lewis Hamilton by half a second, with the Englishman's teammate Jenson Button finishing third.

Romain Grosjean and Kimi Raikkonen, both of Lotus, were fourth and fifth respectively ahead of championship leader Fernando Alonso of Ferrari.

Vettel's Red Bull teammate Mark Webber could only finish seventh after suffering engine trouble and was unable to get out on the 'supersoft' tyres.