FILE PHOTO: International Air Transport Association (IATA) Director General and CEO Alexandre de Juniac speaks during the Global Media Day in Geneva, Switzerland December 5, 2017. REUTERS/Pierre Albouy/File Photo

GENEVA (Reuters) - Airlines face significant problems if the return to service of the Boeing 737 MAX drags on for months longer, the head of the International Air Transport Association said on Wednesday.

IATA Director General Alexandre de Juniac told Reuters many airlines could cope with the latest delay in the plane’s return announced earlier on Wednesday, but were nearing the end of their ability to manage the shutdown smoothly.

The head of IATA, whose 290 airlines represent 82% of global traffic, was speaking shortly after the U.S. Federal Aviation Administration said the jet would not return to service in 2019.

Reacting to the latest delay, de Juniac said, “For some of our members it is disruptive because they have a lot of planes grounded (or) on order, but they have been able to cope with that. They are not happy of course but they are not in despair.”

He added, however, “If it lasts some additional months, for some of our members it would be a big problem”.

De Juniac said he understood why European regulators wanted to conduct their own examination of key MAX software, but called for a return to a system of mutual recognition among regulators for future programs including the upcoming Boeing 777X.