The victim, whose name was not reported, was taken by a group of about 30 gunmen from his residence in the village of Rimi on Thursday, Radio France Internationale reported. The attackers killed two Nigerians, a security guard and a neighbor, during the incident.
The victim works for French alternative energy company Vergnet. Two co-workers who were also staying at the residence were not home at the time of the attack, RFI said.
The kidnappers were "probably linked to AQIM [al-Qaida in the Islamic Maghreb] or the groups which are today in Mali," Hollande said, speaking during a state visit to Algeria.
"We have to be firm when it comes to terrorism, while at the same time maintaining contacts to free" French nationals, he added.
The Islamic terrorist group Boko Haram, which has fought to impose Sharia law in Nigeria, is probably not involved in Thursday's incident because they don't typically stage kidnappings, the BBC reported.