Nico Rosberg & Lewis Hamilton set early pace in Brazil

Mercedes drivers Nico Rosberg and Lewis Hamilton led the way in a wet first practice at the Brazilian Grand Prix.

Rosberg set his fastest lap time early on and no-one got close to the German as he sat out the final half of the 90-minute session.

Hamilton ended up 0.449 seconds adrift with a time set a few minutes later.

Red Bull's Sebastian Vettel took third, with McLaren's Jenson Button fourth ahead of Ferrari's Fernando Alonso and the second Red Bull of Mark Webber.

There were a number of spins and off-track moments in the slippery conditions, including from both Mercedes drivers.

Rosberg, who made the most of fresh tyres to set his fastest time, ran wide at Turn One early in the session, shortly before team-mate Lewis Hamilton half-spun going through Turn Three.

The Englishman was able to keep his engine running and rejoin the session after reversing away from the barriers.

Hamilton was not as happy with his car as Rosberg, complaining of a 'snappy' rear.

Vettel also ran wide at the final corner in the closing minutes, while Alonso, Lotus's Romain Grosjean and Sauber's Esteban Gutierrez were among those to survive wayward moments as their cars struggled for grip.

The rain meant that the teams were not able to do any serious running on a 2014 dry-weather test tyre that Pirelli have taken to Brazil.

Vettel did go out for one lap on the tyre with a rake attached to the rear of the car to measure airflow before being called in.

Russian Daniil Kvyat was impressive in the Toro Rosso, setting the eighth fastest time in only his second outing in an F1 car at a grand prix.

The 19-year-old has run in first practice at the final two grands prix of the season in preparation for his full debut in 2014, replacing Red Bull-bound Daniel Ricciardo.

"Good FP1!" said Kvyat on Twitter. "First time in wet conditions with F1, very important session. P8 in the end! Happy with the result, let's keep it going!"

Lotus's Heikki Kovalainen, standing in for Kimi Raikkonen in the final two races after his fellow Finn had an operation on a long-standing back operation, was ninth, ahead of Sauber's Nico Hulkenberg.

BBC F1 technical analyst Gary Anderson said: "The two Mercedes going out and doing the times they did early on, it looks like they might have a good weekend.

"I think we'll see some dry running in the second session."

Second practice starts at 1600 GMT.

See full first practice result.