A forum for EC officials to explain and defend their apparent plans to change the definition of "parent carrier" is being organised by two industries bodies.
If the change in definition takes place, it will allow de-regulation of CRSs in Europe to go ahead without safeguards despite the stake three major airlines hold in Amadeus.
The Business Travel Coalition (BTC) and the International Airline Passengers' Association (IAPA) are holding a CRS Customer Leadership Hearing in Brussels on September 20.
At the half day event, EC officials will be questioned about their plans on CRS de-regulation and any change in definition of parent carrier by travel associations, among them ACTE, ECTAA and Paragon.
Executives from airlines, CRSs and travel management companies will also give their views.
Kevin Mitchell, chairman of BTC, said he was hoping 125 people would attend the event.
Mr Mitchell told BTE that without consultation the EC Directorate of Transport and Energy (TREN) had "gutted the protections" which the CRS code of conduct offered.
It had done this by ruling that "effective control" was the determining factor in deciding whether an airline was a parent carrier.
"This ignores powerful incentives for abuse that flow from airline ownership of a CRS at any level," Mr Mitchell said.
He added: "The aim of this event is to forge a consensus view about what level of ownership produces the incentives and means for abuse.
"EC regulators in 1989 effectively established that any ownership level was problematic.
"Because of recent communications out of TREN, there is now a need to legislatively clarify, if indeed, any ownership is the criterion that predicts problems, or if problems are more likely to materialise at some threshold percentage of ownership."
Mr Mitchell said the protest letter BTC has written to send to Matthias Ruete, the EC director general for transport and energy can still be signed up until September 10.
To see and sign the letter click on: http://businesstravelcoalition.com/advocacy/campaigns/99.html
* see BTE's recruitment site www.businesstraveljobs.com