Brussels  - The European Union's top consumer-affairs official on Thursday gave EU airlines one year to make their websites honest after a study revealed "appalling" levels of deceptive offers and a weaker than expected ability to change them.

The airlines involved include low-cost giant Ryanair and Austria's national carrier, Austrian, as well as around 70 other airlines and travel companies, officials in Brussels said.

"I intend to wrap this sweep investigation up by May 2009. ... Until I see the market really clean from the point of view of consumers, I will not stop my efforts," EU Consumer Protection Commissioner Meglena Kuneva told journalists.

"If we need to have more measures, I won't hesitate to go further," sanctioning offenders as necessary, she warned.

At the very least, the airlines should provide clear information on the final price which customers will be charged for their ticket and the availability of the price band in question, and make sure that customers are not automatically registered for costly "optional" services, Kuneva said.

In September, consumer officials in 15 EU member states and Norway analyzed the websites of airlines and ticketing agencies in their countries to see whether they presented users with an accurate account of what their tickets would cost.

Kuneva said she was "frankly appalled" by the result, which revealed that 137 of the 386 sites checked broke EU consumer laws by either advertising the ticket at a price which was below the final one, failing to provide appropriate contract information or only applying the advertised low price to a tiny number of seats.

Since then, national enforcement agencies have forced around half of the websites to follow the rules or shut down, Kuneva said.

But only 12 per cent of the problems associated with companies not based in the country where the flawed websites were discovered have been resolved, she said.

"We need to track down and follow the about 70 remaining cases which we detected as bad and false. They need to be either amended or shut down - and we have the right to do so," she said.

Most of the countries which took part in the September sweep have not disclosed the names of the companies involved, saying that they must first finish their own legal proceedings.

But Norway and Sweden have both published the names of the companies their sweep caught out.

Sweden's sweep found flaws in the websites of Irish giant Ryanair and local carriers Gotlandsflyg and Ryanair. Norway's sweep also found flaws in Ryanair's site, together with those of Austrian and Finland's Blue 1 airline.

Blue 1 and Austrian have since amended the offending practices, while Ryanair has been asked to do so, a statement from the Norwegian Consumer Ombudsman's office said. (dpa)