The purchase option at the end of the loan was originally set at 14 million euros ($16.61 million) but, according to local media, Marseille paid about 8 million euros
Marseille have signed Argentina defender Leonardo Balerdi on a permanent basis, the French club said on Saturday.
Balerdi, who joined on loan from Borussia Dortmund last summer, has signed a five-year deal the Velodrome said.
The 22-year-old has two Argentina caps but is not part of the squad that has reached the quarter-finals of the Copa America .
The purchase option at the end of the loan was originally set at 14 million euros ($16.61 million) but, according to local media, Marseille paid about 8 million euros.
Balerdi made 25 appearances for Marseille, including 21 in Ligue 1, scoring two goals. He became a regular starter after fellow Argentine Jorge Sampaoli took over in February.
The signing continues a busy summer in Marseille.
The club had already extended the contract of Spanish centre-back Alvaro Gonzalez and signed young US winger Konrad de la Fuente from Barcelona as well as Brazilian midfielder Gerson from Flamengo.
France attacker Florian Thauvin has moved to Tigres in Mexico where he will join former Marseille striker Andre-Pierre Gignac.
Goalkeeper Yohann Pele, Japanese defenders Hiroki Sakai and Yuto Nagatomo, midfielder Saif-Eddine Khaoui and striker Valere Germain have also left.
Kevin Strootman, who spent last season on loan at Genoa, will be staying in Serie A.
Cagliari announced on Saturday they had signed the Dutch midfielder on loan a temporary basis for one year from Marseille.