Rosberg fastest in Spanish GP practice

(GETTY IMAGES)

Nico Rosberg continued his dominating Formula One practice form today, the Williams driver setting the fastest lap time across two sessions at the Spanish Grand Prix.

Rosberg clocked 1 minute, 21.588 seconds around the Circuit de Catalunya track to lead a Williams 1-2 ahead of Kazuki Nakajima, who was less than two-tenths of a second behind.

Local favorite Fernando Alonso of Renault was third fastest ahead of Brawn GP pair Rubens Barrichello and Jenson Button, who was four-tenths of a second off Rosberg's pace.

Still, recent upgrades appeared to have kept Brawn GP ahead of the field. The team is likely to be the favorite on Sunday with Button having won three of the first four races.

The Briton leads teammate Rubens Barrichello by 12 points in the drivers' championship, with Sebastian Vettel trailing by 13.

Red Bull pair Mark Webber and Vettel were the only other drivers to get within half a second of Rosberg, who pulled his car off the track in the closing moments due to an apparent mechanical failure.

Rosberg has now set the fastest lap time in eight of the season's 13 sessions, but has picked up only 3.5 points from racing.

Ferrari, which is off to the worst start in its 60-year history, continued to sit way off the leader's pace despite an array of aerodynamic upgrades.

Kimi Raikkonen was more than a second behind Rosberg and ahead of teammate Felipe Massa. The last win for Raikkonen, the 2007 world champion who currently has 3 points, came in this race last year.

Defending champion Lewis Hamilton posted a fastest lap of 1:22.809 to be 1.2 seconds off the pace.

Improved performances by Robert Kubica and Nick Heidfeld in the morning session were not repeated in the afternoon, the BMW Sauber pair finishing more than 1.3 seconds behind the Williams cars.

Kubica and Heidfeld finished 18th and 19th at Bahrain, and the German team needs a strong performance in Spain to maintain its championship hopes.