A decision by LUFTHANSA to impose a 16 euro ($18) surcharge to tickets bought outside its websites and booking offices sparked anger Wednesday from travel agencies.

Lufthansa unveiled Tuesday a new commercial strategy and complained that the “global distribution systems” used by travel agents for ticket sales were more costly to it, while offering few of the benefits.

Amadeus, which operates the world’s leading reservation system, said today’s travellers were looking for consistency, transparency and choice.

But Lufthansa Group “have chosen to go in a different direction by introducing charges that will penalise travellers based on the shopping channel they use.”

It said Lufthansa’s introduction of the surcharge in September would make it harder for travellers to make comparisons and search for the best fares.

“Travellers will either pay more for the same service” or end up paying added IT costs of travel agents or ticket websites that modify their systems to access Lufthansa’s own website.

The European Travel Agents’ and Tour Operators’ Associations (ECTAA), which represents some 80,000 companies, called the Lufthansa surcharge “another hidden cost passed on to the consumer and an attempt to make fare transparency and comparison more difficult.”

ECTAA’s head Lars Thykier, said “the new cost charge will increase Lufthansa Group airlines fares in average by more than 5 percent.”

Lufthansa group includes Lufthansa, Austrian Airlines, Brussels Airlines and Swiss.