Hong Kong's Cathay Pacific Airways said on Monday it had started inspecting all its Airbus A350 jets after the in-flight failure of an engine component, sending shares in British engine supplier Rolls-Royce down sharply.

The carrier said it had cancelled 24 return flights operating until the end of Tuesday, and that a number of aircraft would be out of service for several days while the process, which it described as precautionary, was completed.

An Airbus spokesperson referred questions to the airline and to Rolls-Royce (RR.L), opens new tab, which said it was aware of the incident and was committed to working closely with Cathay, Airbus and authorities conducting an investigation.

Shares in the company - the sole engine provider for the Airbus A350 family of long-haul jets - closed down more than 6% and dragged Europe's defence and aerospace index down 2.8%.

According to Flightradar24 data, the problem apparently unfolded several minutes after take-off as flight CX383 initially headed out over the sea, south of Hong Kong.

Instead of immediately turning north for the roughly 12-hour journey to Zurich, the aircraft performed two wide circles before returning to Hong Kong where it landed safely about 75 minutes after take-off, according to the tracking data.

Cathay did not describe the failed engine component in detail but said it was the first of its type to suffer such failure on any A350 aircraft worldwide.

"Thus far we have identified a number of the same engine components that need to be replaced. Spare parts have been secured and repair work is underway," it said.

A person familiar with the matter said the incident involved a problem with a fuel nozzle, a component that directs fuel inside the engine.

Experts say such problems are rare but, barring a deeper flaw, generally raise fewer alarms than the failure of one of the major rotating parts such as a turbine blade. However, any widespread further inspections could be disruptive to airlines.

HONG KONG PROBE

Industry sources said Hong Kong's Air Accident Investigation Authority had quickly launched an investigation. The bureau could not be reached for comment outside office hours.

Britain's Air Accidents Investigation Branch said it would support any investigation carried out in Hong Kong.

According to Flightradar24 data, the diverted aircraft is an A350-1000, the larger of two models of twin-engined A350. These are powered by the XWB-97, Rolls' largest civil jet engine.

Cathay operates 18 of the largest twin-engined Airbus planes as part of a mixed fleet of Airbus and Boeing jets.

It is one of the largest users of the A350-1000 alongside British Airways, which also has 18 in operation, but behind the largest operator, Qatar Airways, according to Airbus data.

There were no immediate reports of similar findings at other airlines. Other operators of the A350-1000 did not immediately respond to requests for comment.

The European Union Aviation Safety Agency (EASA), which is responsible for overseeing Airbus jets and has the power to order fleet-wide checks or repairs, did not rule out taking action but said it would wait for the results of the probe.

"We will be monitoring any information coming out of the technical investigation and will take decisions on any fleet level action as required," a spokesperson said.

In total, Cathay operates 48 A350 jets including the smaller and more widely used A350-900, which runs on a different member of the Rolls-Royce Trent XWB engine family called the XWB-84.

The airline said it was coordinating with the Hong Kong Civil Aviation Department and the jet and engine manufacturers.

Cathay has around 100 planes currently on order including freighters, narrow-bodies and wide-bodies, with rights to acquire another 80.