Raikkonen tops practice 3 - Belgium

The Finn led the way for the majority of the morning, setting an early lap in 1:46.137.

He looked set to beat that time when he switched to softer tyres at the end of the session, but after setting a new best sector time in the first third of the lap, he lost time further around the course.

Massa also failed to make any gains on his own soft tyre run, thanks in part to an error at the Bus Stop chicane.

The McLarens were third and fourth, Fernando Alonso lapping 0.370 seconds slower than Raikkonen but beating teammate Lewis Hamilton by just under three tenths of a second.

The Spaniard had joined the session slightly later than the rest of the front-runners and trailed Hamilton initially before improving at the end of the hour.

BMW's Robert Kubica failed to set a time after coming to a halt with puffs of smoke from the rear of his car on his first flying lap. There was no immediate confirmation of the nature of the failure, or whether an engine change and consequently a grid penalty would be required.

For much of the session the leading four drivers were 1.6 seconds clear of the rest of the field, but that gap closed on the final runs.

Renault's Heikki Kovalainen ultimately took fifth, 0.9 seconds off the pace, ahead of Toyota's Jarno Trulli, Williams' Nico Rosberg, BMW driver Nick Heidfeld, Trulli's teammate Ralf Schumacher and Red Bull's Mark Webber.

Adrian Sutil had run as high as 13th in the revised Spyker, before dropping down to 18th during the final runs.

His teammate Sakon Yamamoto also showed promising pace as he held 16th position in the middle of the session, but he ended practice in the barriers at Fagnes after an apparent mechanical problem at the entry to the chicane.

Pos  Driver        Team                    Time              Laps
 1.  Raikkonen     Ferrari            (B)  1:46.137 +         17
 2.  Massa         Ferrari            (B)  1:46.388 + 0.251   17
 3.  Alonso        McLaren-Mercedes   (B)  1:46.507 + 0.370   10
 4.  Hamilton      McLaren-Mercedes   (B)  1:46.782 + 0.645   14
 5.  Kovalainen    Renault            (B)  1:47.065 + 0.928   13
 6.  Trulli        Toyota             (B)  1:47.218 + 1.081   11
 7.  Rosberg       Williams-Toyota    (B)  1:47.251 + 1.114   16
 8.  Heidfeld      BMW Sauber         (B)  1:47.359 + 1.222   16
 9.  R.Schumacher  Toyota             (B)  1:47.454 + 1.317   19
10.  Webber        Red Bull-Renault   (B)  1:47.527 + 1.390   15
11.  Fisichella    Renault            (B)  1:47.564 + 1.427   16
12.  Button        Honda              (B)  1:47.767 + 1.630   18
13.  Coulthard     Red Bull-Renault   (B)  1:47.806 + 1.669   10
14.  Vettel        Toro Rosso-Ferrari (B)  1:47.838 + 1.701   19
15.  Wurz          Williams-Toyota    (B)  1:47.902 + 1.765   16
16.  Sato          Super Aguri-Honda  (B)  1:48.129 + 1.992   16
17.  Liuzzi        Toro Rosso-Ferrari (B)  1:48.163 + 2.026   21
18.  Sutil         Spyker-Ferrari     (B)  1:48.348 + 2.211   18
19.  Barrichello   Honda              (B)  1:48.528 + 2.391   16
20.  Davidson      Super Aguri-Honda  (B)  1:48.955 + 2.818   16
21.  Yamamoto      Spyker-Ferrari     (B)  1:49.179 + 3.042   14
22.  Kubica        BMW Sauber         (B)  No time             2

All timing unofficial