AIRBUS is today expected to land a blow on deadly rival Boeing when it grabs a huge order from Emirates, the fast-growing Gulf airline.

The order will be for as many as 50 mid-sized A350s, a rival to the Boeing 787 Dreamliner.

The contract will be the corner-stone of what is expected to be one of the biggest aircraft-buying sprees of recent history. Emirates and sister companies will use this week’s Dubai Air Show to place orders for more than 100 aircraft worth as much as $100 billion (£47.7 billion).

The move will underpin the Gulf state’s determination to be one of the most powerful players in world aviation.

Yesterday negotiations were continuing on the exact make-up of the deals. Aerospace sources said that despite the A350 deal, Boeing was still hopeful of winning a large amount of business at the show.

Dubai Aerospace, the aerospace arm of Dubai’s government and a sister company to Emirates, is understood to be poised to announce a major move into aircraft leasing. It is expected to announce on Monday a joint-venture with a big American firm.

The order for the A350 will be a major coup for Airbus. It has been under the cosh in the market for mid-sized planes, having been slow to respond to Boeing’s 787.

The Boeing plane, despite having not yet made its first flight, is already one of the most successful commercial aircraft in history. It has so far racked up more than 700 orders from 48 customers. Airlines have been drawn in by the promise of 20% lower operating costs thanks to the new engines and the widespread use of weight-saving plastics.

The A350 will also use plastics and new-generation engines, but will cover a much wider range of the market. Although the base model, the A350-900, will have 250 to 270 seats, roughly the same as the base 787, there will be a larger version, the A350-1000, which will have up to 350.

It is thought that this option of a larger aircraft swung the deal in Airbus’s favour, because it tallies with Emirates’ ambitious growth plans.

The Gulf airline already has 55 of Airbus’s A380 super-jumbos on order – it accounts for about a third of sales to date – and may announce more A380 orders at this week’s show.

Boeing suffered a setback on the 787 recently when it admitted delays to its production plans. It said the ground-break-ing new plane would be at least six months late, and was unlikely to make its first flight until the first quarter of next year.

Airbus has had its own problems with new aircraft programmes. The A380 is two years late to customers, while last week the company was forced to take an embarrassing hit of up to $2 billion on its A400M military transport plane.

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive