Airlines in the Asia Pacific region will invest more than US$1 trillion over the next 20 years to acquire thousands of new aircraft to meet growing traffic demand, aircraft maker Boeing said on July 2.

The region will need a total of 8,350 new planes over the two decades, Boeing said.

Asia-Pacific is set to be the biggest market for new aircraft deliveries in terms of the value of the orders, accounting for 36 percent or US$1.02 trillion of the US$2.8 trillion airlines are projected to spend in the next two decades, the US aerospace giant said.

Globally, the airline industry will require more than 28,600 aircraft over the next two decades, said Boeing.

Rapid economic growth is one of the key drivers fueling Asia's robust air traffic growth which in turn means airlines in the region will require new planes to cater to more travellers, said Randy Tinseth, Boeing's vice president for commercial airplanes.

"Within the Asia Pacific market, we see the strongest growth at 6.7 percent per year within the region," Tinseth said at a media briefing in Singapore.

"This is a market that continues to liberalize ... This is a market where trade is very strong," he said.

With liberalization in the region as well as globally, airlines will start to offer more non-stop services in order to improve efficiency, Boeing said.

This is where the demand for fuel efficient planes like the 787 Dreamliner will come from, said Tinseth.

"Airlines have accommodated growth in our industry by flying more airplanes to more places rather than flying bigger and bigger airplanes between the destinations," he said.

"Now what's important to us is we expect this trend to continue in exactly the same way ... That's the reason we chose to make an investment in an airplane like the 787."

The 787 Dreamliner is Boeing's new generation mid-sized airliner for long-haul flights and has been marketed as a fuel-efficient plane offering savings for airlines.

The US group said it received more than 630 firm orders for the aircraft, which is to enter service in mid-2008, and the 787 order book is valued at nearly US$100 billion at catalogue prices.

Boeing's 787 continues to eclipse Airbus' rival product, the A350, despite a handful of recent orders for the European group.

Boeing's estimates were backed by the top airline association which said international air travel grew again in May, while air freight picked up sharply after several months of sluggish growth.

Passenger travel rose by 5.5 percent year on year, compared with 5.4 percent a month earlier, the International Air Transport Association said in Geneva.

Demand for air freight rose by 5 percent in May, up sharply from 2.8 percent in April, led by airlines in the Middle East and a doubling of demand in the Asia-Pacific region, it added.

"The pick-up in freight, led by Asia, could be the first sign of strengthening demand," IATA director general Giovanni Bisignani said.

"On the passenger side, growth has stabilized while strong competition is keeping load factors high even as carriers aggressively expand international routes to take advantage of some liberalizing markets."