North African wing of Al Qaeda said it killed a French hostage in revenge for failed rescue raid by French and Mauritanian troops, Al Jazeera reported.

A leader of al-Qaeda in the Islamic Maghreb said Michel Germaneau was killed on Saturday in a revenge for six militants killed on Thursday in the cross-border operation.

"[French President Nicolas] Sarkozy was unable to free his compatriot through this failed operation but he definitely opened one of the gates of hell on himself, his people and his nation," he said in an audio recording aired by the Arabic-language satellite news station.

French officials have not yet confirmed the death.

A retired engineer Germaneau, 78, was kidnapped in Niger in April and was reportedly being held by Abdelhamid Abou Zeid, the leader of one of two al-Qaeda in the Islamic Maghreb wings in the Sahara desert.