Chicago (dpa) - After the debacle on the 737 Max series, the US aviation company Boeing must postpone the launch of the ultra-long-range version of the new model 777X.

Boeing had reviewed the schedule of the development program for the variant 777-8 and adapted, a company spokesman said. But stick to the aircraft type and work closely with the engine supplier GE. In the 777-9 series - which has a shorter range and has ordered 20 from Lufthansa - Boeing is still aiming for its first deliveries by 2020.

No details made Boeing the new schedule for the 777-8. Boeing announced three weeks ago in Chicago that the 777X had "significant schedule risks" due to engine problems. With the shift in the 777-8 Boeing could fall behind in a prestigious project of the Australian airline Qantas behind the European competitor Airbus.

From 2023, Qantas intends to take regular service on the 17,000-kilometer route between Sydney and London. The 21-hour flight would be the world's longest non-stop connection. As aircraft types are a modified version of the future Boeing 777-8 and the ultra-long-haul Airbus A350 in conversation. Qantas boss Alan Joyce had said to the CNN station in June that he hopes to have the offers of the aviation companies in August.

Boeing claims to have orders for a total of 344 777X aircraft in both variants. Lufthansa also wants to introduce a new Business Class with the Boeing 777-9. The first of these aircraft in the Lufthansa fleet had been planned for the summer of 2020. Three weeks ago, however, Boeing had reported then, because of the engine problems, the first flight of the 777-9 had been postponed to early 2020. The aim is therefore to deliver the first machines later in the year.

Two crashes in Indonesia and Ethiopia on Boeing 737-Max aircraft, which killed 346 people in October 2018 and March 2019, plunged the US company into a major crisis. The manufacturer is faced with lawsuits and investigations. Boeing is suspected of rushing the 737 Max because of the fierce competition and neglecting the safety. The Group denies this, but has given glitches. Initial investigation reports pointed to a faulty control software as a cause of the crash.

Whether and when the 737 Max machines, which have been subject to take-off bans since March, may withdraw again is currently unclear. The crisis around the 737 Max series brought Boeing deep into the red. In the second quarter, a record loss of US $ 2.9 billion (2.6 billion) had incurred, as the US aviation giant announced three weeks ago. Boeing had earned $ 2.2 billion in the same period last year. The company did not abandon a new business outlook due to the high degree of uncertainty regarding the intended readmission of the 737 Max.