London - Newcastle United midfielder Olivier Kemen has joined Ligue 1 side Olympique Lyonnais on a four-year contract, according to a statement on the French club's website.
Lyon said they had agreed to pay an initial fee of €750 000 for the 19-year-old Frenchman, in a statement on the club's website.
Newcastle are entitled to a percentage of any fee if the French club sell Kemen on in the future.
"Officially a Lyon player, really very happy to sign for this great club," Kemen said on Twitter on Monday night.
Newcastle signed Kemen from Ligue 2 side Metz in 2013 but he never played for the senior side.