American Santino Ferrucci paces Valencia F3 test
The 16-year-old from Connecticut, who raced with EuroInternational and then Fortec Motorsport this year, is tipped to join the Berlin team for 2015 although nothing has been announced.
Ferrucci leapt to the top of the order with a few minutes remaining to pip Dane Mikkel Jensen, who took over at Van Amersfoort Racing from Monday pacesetter Alessio Lorandi.
Jensen, the ADAC Formel Masters champion, had two days of testing with Mucke last week as he weighs up his 2015 plans.
McLaren AUTOSPORT BRDC Award winner George Russell and beaten finalist Alexander Albon were third and fourth respectively with Carlin and Signature, with BRDC Formula 4 champion Russell fastest until the closing minutes.
Another Briton, Sam MacLeod, was within two tenths of the pace in fifth place with Van Amersfoort Racing.
All the top 10 times were set in the final session of the day, with earlier sessions topped by Albon, MacLeod and, in the wet, Motopark's Markus Pommer.
BERETTA JOINS MUCKE
Italian Michele Beretta has become the first driver confirmed at Mucke Motorsport's F3 European Championship team for 2015.
The 20-year-old from Milan failed to score points in 2014 with EuroInternational, after finishing runner-up in the 2013 Italian Formula Abarth series.