Buemi still on top at Jerez

Buemi's time of 1:18.073 put him over half a second clear of Takuma Sato, as Toro Rosso dominated the session once again.

Buemi and Sato worked alongside Sebastien Bourdais, all three men fighting for the two racing seats at the Italian squad. Four-time ChampCar champion Bourdais was the slowest of the trio, finishing third fastest

McLaren's Pedro de la Rosa was fourth quickest as he worked for the first time with a 2009 front wing fitted to the heavily revised MP4-23A car.

The Spaniard was joined by Finn Heikki Kovalainen, who drove the KERS test car. Kovalainen was sixth fastest behind compatriot Kimi Raikkonen in the quickest of the Ferraris.

Raikkonen was left lamenting the lack of mileage done today, as the track was still wet in the morning.

"We haven't done many kilometres over these two days, because the conditions weren't really good," he said. "We're mainly trying to understand how the slicks work and we're testing some solutions the car will use in the upcoming season.

"It's useless to speculate about what will be in the future. Too many things are different on the cars on the track. To get a precise idea we have to wait until we all have the new cars."

Raikkonen's teammate Felipe Massa arrived at 3:30pm straight from Brazil and joined the session to complete 27 laps.

Two-time world champion Fernando Alonso returned to action following the end of the season, the Spaniard the only Renault driver on track today. Alonso, who covered 105 laps, caused a red flag when he went off track in the morning.

"It was a good day and I'm happy to be back in the car," Alonso said. "Unfortunately I damaged the car a little bit in the morning and so we lost some running, but the team did a good job to repair the car quickly and I was able to run almost all of the afternoon without any problems.

"It was nice to run on the slick tyres as they are more grippy, but when you lose the downforce from the car they don't feel massively different to grooved tyres."

BMW-Sauber duo Nick Heidfeld and Robert Kubica finished as ninth and 11th quickest respectively, the Pole managing just 38 laps after stopping on track around 2pm.

The third red flag of the day was caused by Williams driver Nico Rosberg.

Today's times:

Pos  Driver        Team                      Time     Laps
 1.  Buemi         Toro Rosso-Ferrari   (B)  1:18.073  128
 2.  Sato          Toro Rosso-Ferrari   (B)  1:18.601   38
 3.  Bourdais      Toro Rosso-Ferrari   (B)  1:18.673   81
 4.  De la Rosa    McLaren-Mercedes	(B)  1:19.032   78
 5.  Raikkonen     Ferrari              (B)  1:19.334   89
 6.  Kovalainen    McLaren-Mercedes     (B)  1:19.631   64
 7.  Alonso        Renault              (B)  1:19.907  106
 8.  Rosberg       Williams-Toyota      (B)  1:20.309  122
 9.  Heidfeld      BMW-Sauber           (B)  1:20.365   87
10.  Massa         Ferrari              (B)  1:20.490   27
11.  Kubica        BMW-Sauber           (B)  1:20.954   38

All Timing Unofficial