"Information at Air France's disposal at this stage shows the missile fell into the sea more than 100 kilometres from the trajectory" of flight AF293 from Tokyo to Paris on 28 July, an Air France statement said on Thursday.
"Having learned of this missile test we have decided to establish a wider non-flyover zone to move further away from North Korean territory," it announced.
The missile fell into the sea just minutes after the plane, which was carrying 323 people, passed by the area.
But Air France insisted that the flight's safety was "not in question".
The company does not fly over North Korea but extended the no-flyover zone.
France's UN ambassador, François Delattre, told journalists on Thursday that a resolution for the UN Security Council to slap "new, tough sanctions" on Kim Jong-un's regime was being negotiated and "we are making progress".
His British counterpart, Matthew Rycroft, confirmed that that progress was being made.
Among the sanctions that could be adopted are limiting oil supply to the country, a ban on North Koreans working abroad and new limits on air and sea access.
Russia, which has a right of veto on the council, has warned against measures that could worsen the humanitarian situation in the country.
The UN has imposed six rafts of sanctions on North Korea since its first nuclear test in 2006.