The US and UK ban on laptops in cabin baggage on certain flights will not be an effective security measure, the International Air Transport Association has said.
In a strongly worded speech, IATA chief executive Alexandre de Juniac said the ban also caused commercial distortions.
The US ban was brought in as an anti-terrorist precaution.
It covers inbound flights on non-US airlines operating out of 10 airports in the Middle East, North Africa and Turkey.
The British ban is similar but applies to different airlines, including UK carriers. Airline passengers on 14 carriers are subject to the ban on inbound direct flights from Turkey, Lebanon, Jordan, Egypt, Tunisia and Saudi Arabia.
In his speech in Montreal, Mr de Juniac questioned the measures, saying: "Why don't the US and the UK have a common list of airports? How can laptops be secure in the cabin on some flights and not others... especially on flights originating at a common airport?"
He added: "The current measures are not an acceptable long-term solution to whatever threat they are trying to mitigate. Even in the short term it is difficult to understand their effectiveness. And the commercial distortions they create are severe."
Airlines affected by the ban include Emirates, Qatar, and Etihad.
US airlines have long argued that these carriers are unfairly subsidised by their governments, which the Gulf airlines deny.
Mr de Juniac said that IATA is "deeply concerned with political developments pointing to a future of more restricted borders and protectionism."
The regulations, which officially came into effect on Saturday, were prompted by reports that militant groups want to smuggle explosive devices in electronic gadgets,
Aviation security experts were alarmed by an incident in Somalia last year when insurgent group al-Shabaab smuggled an explosive-filled laptop on a flight out of Mogadishu, blowing a hole in the side of the plane.
The aircraft was still low enough that the pilot was able to land the plane safely.