A leaked internal report says the national cultural differences between the airline group's Dutch and French staff is so acute that it is uncertain 'whether the alliance can survive given the long-standing mutual incomprehension'.
The bank, which recently announced it is keeping its HQ in London, said global banking and markets staff could move to Paris if UK leaves EU.
The airline has also begun dismissal procedures against a fifth employee over violent protests as management announced a plan to cut 2,900 jobs.
Li Jinyuan, head of the Tiens Group and reportedly China's 24th wealthiest person, spent 33 million euros for the four-day vacation.
Reports say wealth management staff were ordered to stay away from France where the bank is under investigation for helping tax evasion.
Angry workers holding two managers in 'boss-napping' at factory in northern France are demanding more money in exchange for loss of their jobs.
Directors of the furniture store chain were questioned about allegations the company illegally used police files to spy on staff and customers.