The acrimonious relationship between Air France and KLM, partners in Europe’s largest airline combine, has worsened, this time over the management of IT operations.

KLM is refusing to hand over various IT activities to Paris, resulting in furious reactions from the French, the Financieele Dagblad reported on Tuesday.

KLM wants to keep its IT operations under its own control. When Air France acquired KLM in 2004 it was agreed that Air France would manage two-thirds of IT operations, KLM the remainder.

But IT now plays a far greater role in airline operations than it did 13 years ago and speed of data transfer is vital, which is a major reason KLM want to retain control, the paper said.

The main French union said in a letter to KLM’s IT managers this attitude reflected the contempt KLM has for Air France, the FD reported.

KLM is very much the junior partner in the combine. Nevertheless  KLM booked operating profit of €681m in 2016, nearly twice the €372m Air France earned in that year.