Traditionally, the US has been the heartland of the global business aviation market, but the picture is changing rapidly. Demand from other markets around the world is growing and already accounts for the majority of new orders for business jets.

The scale of the interest from markets outside North America is helping to assuage concerns that were spreading among the aircraft makers and business jet operators that the industry could face a hard landing in the face of the weakness of the US economy in particular and the turmoil in financial markets.

Canada's Bombardier forecast this month that the worldwide business jet fleet would nearly double during the next 10 years from 12,800 last year to 24,800 in 2017. The share of the fleet accounted for by the US was forecast to drop from 69 per cent to 54 per cent in the same period. The European share of the fleet would almost double from 13 to 25 per cent.

For some the fear remains that the extraordinary surge in demand for business aviation in recent years could still be coming to an end, and that this will occur just as the aircraft makers are embarking on a fresh investment spree. The leading makers - Bombardier of Canada, Cessna and Gulfstream in the US, France's Dassault and Embraer in Brazil - have ambitious spending planned for the development of new ranges of business jets.

There are some straws in the wind to support a more pessimistic outlook.

BBA Aviation, the world's leading provider of service bases for business jets operating under the Signature brand, gave an early warning of signs that private jet flying in the US could be starting to suffer from the weakening economy and credit market.

Simon Pryce, BBA chief executive, said trading this year in the first couple of months had seen "softer fuel volumes" at its bases in North America. Fuelling levels are a key indicator of flight activity.

Air Partner, the world's leading publicly listed air charter broker, has also reported a slowdown in spending by the corporate sector. It said recently that the level of activity in its private jets business remained high, but there was "emerging evidence of corporate belt-tightening, as companies reviewed budgets during uncertain times." Any softening in corporate demand, however, was being compensated for by strong private client business from wealthy individuals.

While economists argue over whether the US is yet in recession, the aircraft makers maintain that, with the surge in international orders, the business aviation industry is much less exposed to the US economy than in the sector's last recession in the early years of the decade.

Private aviation has enjoyed an unprecedented global boom during the past three years, as corporate executives and rich individual customers have sought both to avoid the increasing hassle, inconvenience and delays of flying through congested hub airports and to use business jets to increase executive productivity.

Despite the nagging fears at the back of some executives' minds, for the moment most of the numbers being reported by the business jet makers suggest there is still strong upward momentum. The industry also has the enviable cushion of a strong order backlog that has been built up during the recent years of surging demand.

Deliveries of business jets reached an all-time high last year, as the leading makers including Bombardier, Gulfstream, Cessna, Hawker Beechcraft and Dassault delivered more than 1,000 jets in a single year for the first time.

With the large order backlogs at most manufacturers and waiting lists of two to three years for the most sought-after jets, deliveries are forecast to remain at a high level this year and well into the next decade.

According to the General Aviation Manufacturers Association (Gama), worldwide business jet deliveries rose 28.4 per cent, from 886 in 2006 to a record 1,138 last year.

In the first quarter of this year, business jet deliveries jumped 41 per cent year-on-year from 211 to 297, as the industry raised production to catch up with demand that has created a backlog of more than two years' work.

Alan Klapmeier, chairman of Gama and chairman and chief executive of Cirrus Design of the US, says "a strong worldwide market, especially outside North America, was a driving factor for general aviation in 2007."

Manufacturer backlogs were "strong and we think this bodes well for 2008 and the years beyond," he adds.

Last year was the fourth successive year of growth since the trough of 2003, and according to the latest forecast by Honeywell Aerospace, a leading supplier to the sector, business jet deliveries are expected to rise to more than 1,300 in 2008.

Demand is being stimulated by a surge in product development, and last year marked the first deliveries of significant numbers of very light jets (VLJs), an emerging segment, which is substantially lowering the price of both chartering and buying private jets.

At the other end of the market Aerion, the US advanced engineering group, hopes to reintroduce commercial supersonic flight.

It says it has secured its first letters of intent from potential customers for about 40 of its planned supersonic business jets, although it has yet to agree a manufacturing deal for the aircraft.

The mainstream business jet makers are already working on the development of a large number of new-generation business jets - as many as 20 - that are expected to reach the market during the next decade.

New manufacturers are also breaking into the industry, most notably Brazil's Embraer, which is using the experience and expertise it has built up during the past 15 years in developing regional commercial jets to build an imposing presence in business aircraft.

Embraer has already overtaken its Canadian rival Bombardier to become the leading maker of regional jets, and it has developed an ambitious strategy for capturing a significant share of the corporate jet market during the next decade.

The business jet sector is far more fragmented than regional commercial jets, where Embraer and Bombardier are the only substantial players, and big jets above 120 seats which are dominated by the duopoly players Boeing (NYSE: BA - News) and Airbus.

Embraer's first foray into business aircraft was focused on derivatives of its regional jets with the Legacy 600, a super mid-size jet, and Lineage 1000 in the ultra-large category.

It has raised the stakes with the development of an all-new family of aircraft at the bottom end of the market, the Phenom 100 very light jet and Phenom 300 light jet.

This week, in its latest gamble, Embraer will stage the commercial launch at the European Business Aviation Convention and Exhibition (Ebace) in Geneva of a new family of midsize and midlight business jets, as it seeks to close gaps in its product offering.

Embraer estimates that total investments for the research and development of the MSJ and MLJ models will be about $750m, and it is seeking to bring in risk-sharing partners and financial institutions to support the programme.

The Embraer midsize jet is forecast to enter service in the second half of 2012 and will be followed by the midlight jet a year later.

While the aircraft makers are busy developing new-generation products, the increasing popularity of executive jets is still attracting many more operators into the industry.

Innovative business models are springing up around Europe, led by the new breed of air taxi operators, who are planning to take advantage of the emerging category of very light jets.