A French hostage has been freed almost a year after he was kidnapped in Nigeria by Islamist militants, President Francois Hollande's office said on Sunday.

Francis Collomp, 63, was seized when about 30 gunmen stormed his compound on Dec. 19 in the northern Nigerian town of Rimi, close to the Niger border where al Qaeda's North African wing operates.

"The president expresses his gratitude to the Nigerian authorities, with whom French authorities have collaborated closely on this decisive action," the statement said.

French Foreign Minister Laurent Fabius will leave for Nigeria today to receive Collomp, Hollande's office said.

Ansaru, the militant group that kidnapped Collomp, said soon after his abduction that he had been taken in retaliation for France's military action against jihadi insurgents in nearby Mali and its ban on wearing the full-face veil.

In September, Collomp - an engineer at French renewable energy firm Vergnet - asked for help in a three-minute video posted on a jihadi website.