* Non-stop flights from Sydney to London possible by mid-2025

* A350-1000 en route from Toulouse to Perth - FlightRadar24

* Airbus also preferred supplier for Qantas narrowbody order (Adds flight length, Airbus comment, details of narrowbody plans)

By Jamie Freed and Tim Hepher

SYDNEY, May 1 (Reuters) - Qantas Airways Ltd is set to announce a landmark order for Airbus SE A350-1000 jets capable of nonstop flights from Sydney to London as part of a wider deal with the European planemaker, industry sources told Reuters.

The multibillion-dollar order, to be unveiled in a Sydney airport hangar on Monday, brings the Australian carrier a step closer to launching record-breaking direct flights of nearly 20 hours on the lucrative "Kangaroo route" by mid-2025.

Qantas has touted plans for the world's longest commercial flights for more than five years, but delayed its "Project Sunrise" due to the coronavirus pandemic.

The deal is a breakthrough for veteran Qantas Chief Executive Alan Joyce who has described nonstop Sydney-London flights as the Holy Grail for the 101-year-old carrier.

The Australian airline launched the route in 1947 with Lockheed Constellations, when it took several stops and 58 hours of flying. Today's one-stop flights take almost 24 hours.

The expansion comes days after Boeing Co further delayed development of its 777X jetliner, which had at one stage been in contention to allow direct flights from Australia's east coast to London and New York.

An Airbus-owned A350-1000 was flying on Sunday from Toulouse to Perth, tracking service FlightRadar24 showed.

Qantas, which has said it would make a significant announcement on Monday about the future of its network, declined to comment. Airbus also declined to comment.

On Sunday, the West Australian newspaper said, without citing sources, that the Qantas order would include 12 A350s, 20 A321XLRs and 20 A220s as well as purchase rights for 106 more airplanes spread among the different types.

Qantas in December selected Airbus as the preferred supplier for a major order to renew its ageing narrowbody fleet, in a blow to its incumbent supplier Boeing.

An airBaltic A220 was parked in Sydney on Sunday, FlightRadar24 showed. That destination is not on a normal route for the European carrier. Australia has no A220 operators at present. (Reporting by Jamie Freed in Sydney and Tim Hepher in Paris; Editing by William Mallard and Clarence Fernandez)