The trio are described as in their forties with previous convictions. They were arrested on Saturday in Paris and the Corsican city of Ajaccio.
Jacques Dallest, the prosecutor in Marseille, said in a statement that Andre Bacchiolelli and Mickael Ettori were charged with murder and receipt of stolen goods in an organised gang, while Pascal Porri was charged with criminal conspiracy to commit murder and receipt of stolen goods in an organised gang.
French Interior Minister Manuel Valls praised the authorities after the suspects were charged, denouncing what he called "a core of criminals from Ajaccio that are particularly dangerous."
Among the others who have been arrested since March 27 in the investigation, one has been released without charge and three others have become cooperating witnesses.
Sollacaro was the most high-profile victim of a spate of killings that has been linked to feuds between rival criminal gangs with connections to sections of the Corsican nationalist movement.
He died in an execution-style hit at a petrol station in Ajaccio on October 16 last year. He was one of at least 25 victims of unexplained murders on the island since the start of last year.
A former chairman of the Corsican bar, the 63-year-old Sollacaro was best known for having defended Yvan Colonna, the nationalist currently serving a life sentence for the 1998 assassination of France's top official on the island, the prefect Claude Erignac.