The European Commission has publicly reprimanded Emirates, Turkish Airlines , Royal Air Maroc and six other airlines for persistently misleading customers on their websites.
Another group, including British Airways, Air France/KLM, Germanwings, Niki and Sky Europe, are holding talks with the Commission to improve the accuracy of their websites.
Many of the complaints refer to deceptive "headline" prices, which disguise hidden extra costs.
To comply with EU consumer protection rules, websites were judged according to a 14-point checklist, which asked if all such extras such as taxes, charges and fees were included, and if extra costs were added as opt-in or opt-out options.
While 115 of the offending websites have since agreed to comply with EU rules, the nine airlines either ignored or responded inadequately to complaints, said consumer protection commissioner Meglena Kuneva.
"This a signal that they do not care about their customers," Kuneva said.
However, officials pointed to the fact that the vast majority of airlines – 52 out of 67 – have either been given a "clean bill of health", or have promptly committed themselves to addressing the issues raised.
That list now includes previous offenders such as low-cost carrier Ryanair and Austrian Airlines.
"This first pan-European enforcement investigation has shown it has real teeth and can deliver," Kuneva said.
by Ian Jarrett
