Women employees of Air France will be allowed to opt out of working on the resumed flights to Iran so that they can avoid having to wear a headscarf, a company official says.

Last week, company chiefs sent out a memo informing female staff they would be required "to wear trousers during the flight with a loose-fitting jacket and a scarf covering their hair on leaving the plane", in accordance with Iranian law.

But a number of female Air France cabin crew staff immediately resisted the ruling, according to a union representative.

In response, the airline now says it will appoint a "special unit" to replace those who do not wish to fly to Tehran.

"Any woman assigned to the Paris-Tehran flight who for reasons of personal choice would refuse to wear the headscarf upon leaving the plane will be reassigned to another destination, and thus will not be obliged to do this flight," human resources official Gilles Gateau said.

Air France is to resume on April 17 its Paris-to-Tehran services, which had been suspended since 2008 because of international sanctions against Iran over its nuclear ambitions.

The headscarf rule is already in place when flying to certain destinations such as Saudi Arabia.

Unions, who held talks with the human resources chief on Monday, argue that an escape clause was already in place for flights to Conakry in Guinea during the Ebola crisis last year and for services to Tokyo following the 2011 Fukushima nuclear disaster.

AFP