TUI Group wrote off EUR20 million euro (USD23.6 million) in the first quarter of 2018 due to the impact of Niki (Austria)'s bankruptcy, the leisure group revealed in its half-yearly financial statement.

"We still had open account receivables with them and they didn't pay them. That's a one-off effect," Group CEO Friedrich Joussen said during an investor's call.

The group, through its German unit TUI fly (Germany), had been wet-leasing fourteen Boeing B737 aircraft to Air Berlin (1991) since 2009. The German airline, in turn, transferred these aircraft to its subsidiary Niki at the beginning of 2017. In November 2017, TUI fly took back seven of them. At the moment of Niki's bankruptcy in mid-December 2017, it continued to operate the remaining seven units. Subsequently, these leases were taken over by Lufthansa Group which continues to wet-lease them through its low-cost unit Eurowings.

Lufthansa Group's bid for Niki was blocked by the European Commission. The airline was subsequently taken over by Niki Lauda and restarted under the name of LaudaMotion.

In sum, TUI Group posted a EUR200.2 million euro net loss for the first half of its financial year, running from October 1, 2017, through March 31, 2018.