PARIS—A Paris court has convicted four Somalis in a 2008 attack on a French luxury vessel and acquitted two others.

Sentences handed down late Thursday for the attack on the Ponant in the Gulf of Aden ranged from four to 10 years. The 10-year prison term went to the only man who admitted he was a pirate, 31-year-old Ismael Ali Samatar.

Two other Somalis who said they boarded the boat received seven-year prison terms. The driver of a pick-up truck used to flee was given a four-year term for complicity.

The 30 people on the Ponant were freed after its owner paid a ransom of $2.15 million. The French army arrested the six on Somali territory.