Travelport claims it is seeing shifts away from bookings for Lufthansa flights since the introduction of the carrier's surcharge.
President and CEO Gordon Wilson says the larger switch in volumes has been observed on online travel agencies that use a global distribution system such as Travelport to sell Lufthansa tickets.
Although there are no official numbers to share and "it is still early days", Wilson says there is also a "noticeable" - but not as sizeable as the OTAs - move away to other carriers within its corporate travel agency customer base.
The airline introduced its highly contentious Distribution Cost Charge (Euro 16 per ticket via a GDS) on September 1 this year.
Last week it conceded that in its overseas markets it is experiencing some "headwinds" since the charge began.
Wilson says Travelport has no particular evidence of intermediaries using the Lufthansa direct platform as a means of avoiding payment of the GDS fee.
Earlier today, Travelport reported a net revenue increase of 2% for the first nine months of 2015 to $1.686 billion, compared to the same period in 2014.
An increase of 6% year-on-year put net revenues at $560 million in the third quarter of this year.
Adjusted EBITDA fell by 6% to $405 million for the year to September, with Q3 down 2% to $131 million compared to Q3 2014.
The company's non-air revenues on its Travel Commerce Platform came in at $129 million in the third quarter of 2015, a 17% increase year-on-year. Air's contribution was $399 million, up 2% over the same period.
Non-air now accounts for around a quarter (24%) of all revenue on the platform.
Payment system provider eNett brought in $27 million during Q3, up 49% year-on-year.
CEO and president Gordon Wilson says the revenue growth has been driven in particular by its activities in Europe and Asia-Pacific.
The company is forecasting it will make somewhere in the region of $2.180 billion and $2.220 billion for the full year, with adjusted EBITDA at around the $528 million to $533 million mark.