Airbus will be looking for a long-awaited new order for its A350-1000 mini-jumbo at this week's Farnborough Airshow, with Hong Kong's Cathay Pacific tipped as most likely to end the model's three-year order drought, industry sources said.

Cathay Pacific has 36 of the A350-900 base model on order, and may add on further orders for the stretched A350-1000 or convert some of its existing orders, or both, the sources said.

Airbus and Cathay Pacific declined to comment.

Airbus says the future 350-seat carbon-composite passenger jet will be significantly more efficient than Boeing's 777 but has so far been unable to make a significant dent in the 777's hold on a lucrative corner of the jet market, just below 400 seats.

Airbus is building the first A350-900 test aircraft and has a total of 548 of the three variants of long-distance twinjet on order. Of these 62 are for the A350-1000.

Some Middle East airlines have complained about the range of this largest variant, prompting Airbus and engine maker Rolls-Royce to bolster the engine design and relaunch the aircraft at the Paris Air Show last year.

Airbus attributes slow sales of the A350-1000 to the lack of availability before late in this decade, but Boeing continues to post strong sales of the 777 which had a record year in 2011.

Boeing is touting a more efficient 407-seat version of its most profitable jet with new engines to try to stay ahead of the A350-1000 which is based on a lighter fuselage.

The A350 family also competes with the 787 Dreamliner.

Eyes at the July 9-15 event will also be on the lower end of the long-distance wide-body market where the reverse is happening - Airbus prolonging the life of a current-generation aircraft with good sales of the A330, while Boeing prepares to answer back with a possible next-generation type called 787-10.

A potential Philippines order for A330s could add to what some sources say could be a busier-than-expected event for Airbus, which tends to spring Air Show surprises, while Boeing is dampening widespread reports of an order blitz by insisting it builds up its portfolio as orders come in over the year.

Airbus sales chief John Leahy said in an interview last week he did not expect to sell as many aircraft as Boeing at Farnborough, while Boeing Chief Executive James McNernney told European newspapers on Sunday it could outsell Airbus for "a number of years" having trailed for nearly a decade.

Airbus outsold Boeing by a record margin last year.

The two planemakers have most of the market for narrowbody short-haul planes and control all the market for wide-bodies.

Including smaller competitors, global jet sales are estimated at approximately US$100 billion a year.