(Reuters) -Swiss tennis great Roger Federer waved the French flag to get the 93rd edition of the 24 Hours of Le Mans underway on Saturday, with Porsche immediately seizing the lead from Cadillac.

Cadillac had swept the front row in Thursday's qualifying but any advantage was short-lived as Porsche Penske's Julien Andlauer slipstreamed into the lead from third on the grid before the first chicane on the opening lap.

The race at the Sarthe circuit in north-west France features 62 cars shared by 186 drivers from 34 countries and is the fourth round of the World Endurance Championship, with 21 hypercars in the battle for overall victory.

Organisers have put the total weekend attendance at more than 300,000 spectators.

Ferrari have won the last two editions and will be able to keep the trophy at their Maranello factory if they complete a hat-trick.

After a French air force flypast, retired 20-time grand slam winner Federer waved the flag to release the field in a rolling start for a race through the night and into Sunday afternoon.

(Reporting by Alan Baldwin, Editing by Andrew Cawthorne)