France is now free to send its peacekeepers to other crisis management operations.
France asked Finland for help last year after the terrorist attack in Paris. Finland decided to offer its assistance in December.
Finland already has a presence in Lebanon of about 300 peacekeepers. About half of them will leave in November, when the United Nations Interim Force in Lebanon (UNIFIL) leadership is transferred from Finland to Ireland.
About 300 Finnish troops will remain after the new forces depart for Lebanon.
In order to help France, Finland also decided to strengthen its training operations in Erbil, Iraq.