Boeing forecasts a $4 trillion market for new aircraft over the next 20 years with a significant increase in forecasted deliveries.

According to its annual commercial aviation market analysis – Boeing 2011 Current Market Outlook (CMO) – released on Thursday in Paris, the aircraft maker foresees a market for 33,500 new passenger airplanes and freighters between 2011 and 2030.

?The world market has recovered and is now expanding at a significant rate,? said Randy Tinseth, vice president of marketing, Boeing Commercial Airplanes in a statement released on Friday.

?Not only is there a strong demand for air travel and new airplanes today, but the fundamental drivers of air travel – including economic growth, world trade and liberalisation -all point to a healthy long-term demand,? he added.

Passenger traffic is expected to grow at 5.1% annual rate over the long-term and the world fleet is expected to double by 2030. The single-aisle market will continue to see strong demand around the world and is expected to increase its share of the market.

Fleet composition will change significantly by 2030 with single-aisle jets making up 70% of the total from the current 60% with that of twin-aisle to account for 22% then from 19% now.

Meanwhile, robust growth in China, India and other emerging markets will lead to a more balanced airplane demand worldwide.