The Scot sped round the testing seven-kilometre Luxembourg circuit in nine minutes 13 seconds, five seconds adrift of defending champion Lance Armstrong.

Millar also bagged the race's white jersey for the best rider under 25.

But the talented climber vowed to make an impact elsewhere in this year's race.

"I've got bigger objectives this year. I didn't come to the Tour just to do a good ride in the prologue," he said.

"But I felt good and I'm happy. Fifth place and the white jersey is a great result. I'm on the podium at the Tour de France and that's always very good."

Millar, 25, who won the prologue on his Tour debut in 2000, was hampered by a virus infection earlier this season and only started racing in May.

"I lost the race throughout the seven kilometres but I was especially tired in the last kilometre," said the Cofidis rider, who finished 62nd in 2000 and retired early last year.

"I didn't go too hard on the climb because I didn't want to blow up but even so I didn't have anything left in the final four hundred metres.

"I think I'm going to suffer in the first week of the race because I haven't raced that much but that also means I've got fresh legs.

"I want to go well in the second half of the race."

Sunday's first road stage is a 195-km lap around the Luxembourg countryside.