Niki and Air Berlin would exchange several aircraft to harmonize each fleet. It had also been announced that Niki would take over several routes to southern European, north African, and Turkish leisure destinations from Air Berlin as part of the new joint-venture. However, the sale never happened. Also in December 2016, Niki announced the termination of its only medium-haul route, from Vienna to Abu Dhabi, Etihad's home base, by March 2017. Niki later also announced it plans to terminate all of its 12 routes from Vienna to non-leisure destinations such as Milan or Zürich by 30 January 2017. In January 2017, it was also announced that Niki will cease all operations to and from Linz Airport at short notice due to the restructuring measures. The announcement was made after the 2017 schedule had already been made available for booking. For the 2017 season, Niki reduced the number of flights from Austria to 56 flights a week to 20 destinations, compared to 34 destinations in 2016. Shortly after, it was announced that Niki would take over several Air Berlin leisure routes to and from Germany. It also has been announced that Niki's fleet will be switched over to Airbus A321s only while the smaller A319s and A320s are handed over to Air Berlin. It has also been announced that TUI fly Deutschland will additionally start to operate 15 Boeing 737s currently wet-leased to Air Berlin for Niki. Failed takeover by Lufthansa and IAG On 17 August 2017, Niki's parent Air Berlin announced it was filing for bankruptcy but that all operations would continue until further notice. On 9 October 2017, Air Berlin told its staff that it would cease all remaining operations under its own brand name, but that Niki flights would continue after this date. On 12 October 2017, it was announced that German Lufthansa would purchase some of the assets from Air Berlin which included Niki and operations would continue and jobs were to be saved. On 24 October 2017, it was announced that Niki was to be absorbed into Lufthansa's low-cost subsidiary Eurowings Europe. It was announced that Lufthansa plans to cease the Niki brand by the end of 2017 altogether. However, on 13 December 2017, Lufthansa pulled out of the agreement due to signs from the European Commission that the merger would not be approved. Niki declared bankruptcy and ceased all operations on 14 December 2017. The