Boeing, the US aerospace giant, and Airbus, its European rival, have both taken orders worth billions of dollars at a major international airshow in Britain, the two companies said.

The Farnborough airshow, which opened on Monday in southern England, is expected to see a return to major business in a sign that the economic downturn plaguing the global aviation industry could be ending.

Boeing said it had won a $9.1bn order from Emirates for 30 777 jets while Airbus said it won a $4.4bn order for 51 A320 jets from the Air Lease Corporation in the US.

The orders are part of a tentative upswing in civil aircraft demand, driven mainly by emerging markets and low-cost carriers.

"I think what you're going to find this week is that both Airbus and the Boeing company will be announcing quite a number of orders," Jim Albaugh, the chief executive of Boeing Commercial Airplanes, said.

Emerging markets

Albaugh added that Boeing and Airbus could be facing increased competition from emerging markets for their smaller civilian planes.

"You've got [plane manufacturers] Comac in China, Embraer in Brazil, Bombardier in Canada, Mitsubishi in Japan and you may have somebody from Russia.

"Our assumption is that they will be successful in developing aeroplanes. The first aeroplane might not be a great one but by the time they do their second and third one they'll probably have very competitive aeroplanes in the market."

Farnborough hosts the massive aviation and arms jamboree every other year, rotating with Le Bourget near Paris.

The star attraction is likely to be the fuel-efficient Boeing 787 Dreamliner, a plane now in testing and built from light-weight composite materials.

It arrived on Sunday, thrilling crowds of aviation enthusiasts. The mid-sized aircraft - Boeing's first new model in a decade - is capable of flying long-haul routes with up to 20 per cent less fuel.

Airbus will be showing off its A400M military transporter plane and attempting to draw a line under its own delays and cost overruns with a marketing ploy over the plane's name.

Analysts expect the event to be more upbeat than last year's sister show in Le Bourget, but are not expexting the record-breaking $88.7bn worth of orders
announced in Farnborough in 2008.

"A lot depends on if the economic recovery continues, if there is a double dip in the recession, then all bets are off," Raymond Jaworowski from Forecast International said.

"We should start to see orders accelerate late this year."