Button third as Rosberg tops storm-hit practice

AFP - Jenson Button, hoping to be crowned world champion in Sunday's Brazilian Grand Prix, took third in Saturday's storm-hit final free practice behind Nico Rosberg.

Button's chief rival, Brawn GP teammate and local hero Rubens Barrichello, struggled in 14th, one place ahead of the Briton's other main title contender, Sebastian Vettel of Red Bull.

Button needs to finish third or better on Sunday to wrap up the title.

Rosberg topped the times after a tropical downpour reduced the session to a 15-minutes lottery on a track awash with water.

The German-born son of 1982 champion Keke Rosberg, driving a Williams, managed to avoid trouble and clock the best time in a brief period of action in difficult conditions.

The storm was so bad that it made it impossible for the Interlagos circuit's medical helicopter to take off, rendering it impossible for the session to begin on time or start until the weather improved.

The track was flooded in parts and the teams' garages and parts of the media centre also suffered from the heavy downpour with standing water and leaky roofing proving the major troubles.

The session eventually began 45 minutes later and allowed only limited running with Rosberg taking the top spot ahead of his Williams team-mate Japanese Kazuki Nakajima.

Next came world championship leader Button of Brawn GP ahead of Ferrari-bound Fernando Alonso of Renault, German Adrian Sutil of Force India and Frenchman Romain Grosjean in the second Renault.

Rosberg's best lap was one minute and 23.182 seconds, more than 11 seconds slower than the lap times recorded in drier running, in damp conditions, on Friday.

Both Alonso and Kimi Raikkonen of Ferrari aqua-planed off the circuit at the exit of Turn Five where Grosjean also spun off heavily into the barriers in the final minutes. The session was red-flagged, almost appropriately, and abandoned.

Further heavy storms are forecast for Saturday afternoon when qualifying is scheduled to take place.