London  - US aircraft maker Boeing Wednesday forecast an annual 5 per cent growth in the worldwide aviation industry over the next 20 years, fuelled by a global shift in demand for more efficient aircraft.

Presenting its 20-year forecast of air travel in its 2008 Current Market Outlook in in London Wednesday, Boeing predicted a market of 3.2 trillion dollars for new commercial planes by 2027.

It estimated that replacement demand would increase to 43 per cent "in light of higher fuel costs."

According to Boeing, airlines would buy 29,400 new passenger and cargo planes by 2027, with China, India, Asia, the Middle East and Latin America emerging as key markets.

Demand would be driven by the desire to replace older aircraft by new, more fuel-efficient planes.

The company said its predictions had taken into account the industry's "near-term challenges," including a global economic slowdown, surging fuel prices and slowing traffic growth in some markets.

"We're facing a very dynamic situation today in the commercial aviation industry," Boeing Commercial Airplanes Vice President, for Marketing, Randy Tinseth, said.

"This year's forecast is rooted in today's realities, but also recognizes the nature of a long-term outlook," he said.

Boeing expects a global fleet size of 35,800 planes by the end of the 20-year period, compared with 19,000 at present. (dpa)