Emirates has fired its strongest warning shot yet across the bows of troubled airline manufacturer Airbus – cancelling a firm order for ten mid-sized A340 jets and sending a team to France to assess the accuracy of promised delivery dates for the A380 superjumbo.

Dubai-based Emirates, which operates twice-a-day services out of Birmingham International Airport, yesterday said it was also axing options on a further ten A340-600 airliners.

The airline has ordered 45 A380s in a deal worth around $13.5 billion (#7.1 billion), making it the programme's largest customer.

An Emirates spokeswoman said: "Emirates confirms it will not be taking delivery of its order and option for 20 Airbus A340-600 aircraft."

She also confirmed the company was "sending a team of technicians from its engineering department in mid-November to Toulouse in order to assess if the revised timings we have been given for the delayed delivery of our A380s are achievable".

Earlier this month Emirates said it was "reviewing all its options" after a further ten-month delay on delivery of its order of 45 Airbus A380 jumbo jets. At the time Emirates described the delay as "very serious" but yesterday it was made clear the order still stood.

The spokeswoman said Emirates had made no decision to buy other aircraft to replace the cancelled order for ten A340s and the cancelled option for another ten of the same aircraft.

"We're in discussion with the manufacturer," she added.

The ten-month delay on the superjumbos followed earlier announcements of delays totaling one year.

Airbus – a major source of work for aerospace component manufacturers in the West Midlands – announced a six-month delay early in 2005, and a second similar delay in June this year.

Airbus, owned by the European Aeronautic Defence and Space Company (EADS), said it was not aware that Emirates was cancelling any of its A340 orders.

However, the Toulouse-based manufacturer insisted that Emirates' assessment of A380 delivery dates was something that had already been agreed. So far Airbus has won firm orders for 159 A380s. On Sunday Australian airline Qantas confirmed an intended order for eight of the huge airliners, despite its production problems.

In July, Singapore Airlines said it planned to order nine more A380s, but no firm order has yet been placed.

Qantas chief executive Geoff Dixon said in a statement: "Our decision to increase our order to a total of 20 has been made after an extensive review of the recent problems at Airbus and the delivery schedule delays of the A380.

"We are convinced that these problems relate to industrialisation issues at Airbus and will be remedied, and in no way relate to the technical capacity of the A380.

"The A380 has breakthrough technology and everything we have seen reinforces our view that it is the best available aircraft for Qantas."

The A380s will be deployed on dense long-haul routes from Australia to the US, Britain, Europe and possibly the Middle East. Mr Dixon said Qantas had also contracted with Airbus arch-rival Boeing to acquire up to 115 B787 Dreamliner aircraft from 2008. , describing the new generation aircraft as having "the very latest technology for aircraft in the 300 seater range".

The Airbus A380 will be capable of carrying 840 passengers.

"The Boeing 787 and the Airbus A380 both have up to 20 per cent lower operating costs than existing aircraft and will form the nucleus of the fleets out to 2015 for Qantas and our low cost airline Jetstar," Mr Dixon said.