Former world champion Mika Hakkinen was the slowest man on the track on Thursday in his first Formula One test for McLaren in more than five years.

The 38-year-old Finn, who retired from the sport after the 2001 Japanese Grand Prix at Suzuka, completed 79 laps on a cold but clear day at the Circuit de Catalunya to the north of Barcelona.

His fastest lap time was one minute 19.336 seconds, unofficial timings provided by McLaren showed -- leaving him 18th of 18 drivers present.

That was more than three seconds slower than Ferrari's Italian test driver Luca Badoer, lapping in 1:16.318, and more than two adrift of 21-year-old British rookie Lewis Hamilton in the other McLaren.

"I didn't expect to be quick straight away, and Barcelona is of course a hard track on both the car and driver," said the 1998 and 1999 champion in a team statement.

"It took several laps before I was up to speed, but we were all expecting this to be the case."

Hakkinen has spent the last two seasons in the German DTM touring car series but had wanted to try out a modern Formula One car.

McLaren, who failed to win a race last year and are switching from Michelin to Bridgestone tyres now that Formula One has a single supplier, had said they hoped for some useful information from his drive.

"Although it was great fun today I also had to do some serious work for the team, as any feedback I could give them from today's experience will help them with their preparations for the 2007 season," said Hakkinen.

"As a result I was really pushing to try to do the best job that I could to assist them in any way possible."

Hamilton continued to learn with his best day yet, setting the fourth fastest time.

"It is early days still but this week has been really positive," he said.