Kevin Magnussen sets practice pace ahead of Spa British F3 round

The Dane set a best lap time over 0.6 seconds faster than his Carlin team-mate and championship leader Felipe Nasr to lead the way in the morning, before the notoriously fickle Ardennes weather washed out Thursday afternoon's session.

"It's so hard to predict these things now," said Magnussen, who has been fast in free practice during the past two rounds but suffered problems in some of the races.

"This is a new weekend on a really good track - one of the best in Europe - so I'm really looking forward to it. It's good to be here with Carlin because they have such a good car."

Nasr edged F3 Euro Series points leader and wet weather pacesetter Roberto Merhi of Prema Powerteam into third by just 0.007s. The Spaniard, who also leads the inaugural FIA International Trophy contest of which this weekend's first and third races are a part, lapped a further 0.315s quicker than Carlin rookie Jack Harvey.

Italian F3 racer Raffaele Marciello, who tested at Spa recently with Prema ahead of an Italian F3 round in August, went fifth fastest, ahead of Carlin trio Jazeman Jaafar (who caused a red flag by crashing out at Pouhon towards the end of the later wet session), Carlos Huertas and Rupert Svendsen-Cook.

Some felt the later wet session should have been red flagged early owing to standing water on the track. Officials conceded a race would not have been run in the conditions, but decreed that the drivers' participation in free practice was at their own discretion.

Signature duo Laurens Vanthoor and Carlos Munoz rounded out the top 10, while series returnee and 2007 champion Marko Asmer (Double R) ended up 11th after setting an identical best time to Munoz.

Euro Series frontrunner Daniel Juncadella wound up 27th of the 28 runners after crashing his Prema-run Dallara heavily at Les Combes after just two laps of the morning session.

Pos  Driver                Team            Car            Time       Gap
 1.  Kevin Magnussen       Carlin          Dallara-VW     2m14.299s
 2.  Felipe Nasr           Carlin          Dallara-VW     2m14.942s  + 0.643s
 3.  Roberto Merhi         Prema           Dallara-Merc   2m14.949s  + 0.650s
 4.  Jack Harvey           Carlin          Dallara-VW     2m15.264s  + 0.965s
 5.  Raffaelle Marciello   Prema           Dallara-Merc   2m15.438s  + 1.139s
 6.  Jazeman Jaafar        Carlin          Dallara-VW     2m15.443s  + 1.144s
 7.  Carlos Huertas        Carlin          Dallara-VW     2m15.517s  + 1.218s
 8.  Rupert Svendsen-Cook  Carlin          Dallara-VW     2m15.916s  + 1.617s
 9.  Laurens Vanthoor      Signature       Dallara-VW     2m15.924s  + 1.625s
10.  Carlos Munoz          Signature       Dallara-VW     2m15.938s  + 1.639s
11.  Marko Asmer           Double R        Dallara-Merc   2m15.938s  + 1.639s
12.  Pietro Fantin         Hitech          Dallara-VW     2m16.016s  + 1.717s
13.  Marco Wittmann        Signature       Dallara-VW     2m16.184s  + 1.885s
14.  Hannes van Asseldonk  Van Amersfoort  Dallara-VW     2m16.399s  + 2.100s
15.  Menasheh Idafar       T-Sport         Dallara-VW     2m16.431s  + 2.132s
16.  William Buller        Fortec          Dallara-Merc   2m16.442s  + 2.143s
17.  Scott Pye             Double R        Dallara-Merc   2m16.776s  + 2.477s
18.  Daniel Abt            Signature       Dallara-VW     2m16.915s  + 2.616s
19.  Harry Tincknell       Fortec          Dallara-Merc   2m16.992s  + 2.693s
20.  Hywel Lloyd           Sino Vision     Dallara-Merc   2m17.103s  + 2.804s
21.  Bart Hylkema          T-Sport         Dallara-VW     2m17.279s  + 2.980s
22.  Luis Derani           Double R        Dallara-Merc   2m17.339s  + 3.040s
23.  Lucas Foresti         Fortec          Dallara-Merc   2m17.595s  + 3.296s
24.  Yann Cunha            T-Sport         Dallara-VW     2m17.604s  + 3.305s
25.  Adderly Fong          Sino Vision     Dallara-Merc   2m17.946s  + 3.647s
26.  Fahmi Ilyas           Forr            Dallara-Merc   2m18.457s  + 4.158s
27.  Daniel Juncadella     Prema           Dallara-Merc   2m18.615s  + 4.316s
28.  Kotaro Sakurai        Hitech          Dallara-Mugen  2m19.358s  + 5.059s