The Rapax driver came out on top during a flurry of activity in the morning session, as most drivers ran the soft tyre compound once the track had dried out.
Coletti was also one of the leading runners in the slower afternoon session, setting the second fastest time on the hard tyre as Felipe Nasr led the way with a soft compound run.
Marcus Ericsson, who had been setting the pace before Coletti's run in the morning, ended the day with the second fastest time overall.
Nasr's afternoon lap was good enough for third on the day, while the top five was completed by Stephane Richelmi and Jolyon Palmer.
Only 25 of the 26 cars featured on track for the final day of the test, as Trident ran a sole car for Rodolfo Gonzalez.
The Italian team had planned not to run at all as Gonzalez initially felt too ill to drive. It did not have a driver for its second car either as Formula Renault 3.5 champion Robin Frijns switched to new team Russian Time, and Nathaneal Berthon, who Frijns had filled in for on the first two days, continued to be sidelined by contractual issues.
The GP2 season kicks off at Sepang, where it will support the Malaysian Grand Prix on March 22-24.