The move increases speculation that Singapore's Changi Airport will eventually become a regional hub for the budget carrier's international operations.

Qantas-owned Jetstar will operate a twice-daily return service between Australia and Singapore from April 17, when the Melbourne route will open.

From Feb 1, Jetstar's Australia-based operations will serve the daily Cairns-Darwin-Singapore route, which is currently being operated by Jetstar Asia.

Jetstar chief executive Alan Joyce said that the new Melbourne-Darwin-Singapore flight will be supported by the airline's rapidly expanding fleet of narrow-bodied aircraft. One-way fares will start at S$88.

On Wednesday, the airline was offering special Web sale fares on the Singapore-Darwin route - a staggeringly low fare of S$8, excluding surcharges.

'By having maintained the lowest-cost operations in the Australian market, this will also support a sustainable low fares position on this new flying market,' Mr Joyce said.

With two of Jetstar Australia's international operations being routed through Darwin, the Northern Territory capital is shaping up to play a key role in the carrier's overseas ambitions.

'Our latest international service could also provide the catalyst for a growing hub from northern Australia's air gateway in Darwin,' Mr Joyce admitted.

Airline spokesman Simon Westaway told The Straits Times from Melbourne on Wednesday that while Darwin could become the gateway to a lot of Asian markets, Singapore too was likely to play a significant role.

'Singapore has been very important to the Qantas group for a long time and from Jetstar's point of view it could become more important,' he said.

'We have good relations with the Singapore airport authorities and from Jetstar's perspective we see a lot of potential there,' he went on. 'It could become very important in our long- term strategy.'

Wednesday's announcement will further reinforce rumours that Singapore is likely to become the regional hub for joint long-haul services to Europe by Jetstar Australia and its Singaporean affiliate, Jetstar Asia.

Using Changi, which is already fed by Jetstar Asia's intra-Asian network, would enable both airlines to take advantage of the more liberal air rights enjoyed by Singapore carriers in Europe.

With the two airlines keen to exploit the low-cost, long-haul travel market, a joint operation would make economic sense as well.

Jetstar Australia hopes to start flying to Rome and Athens by the end of next year, depending on the arrival of its new fleet of 787 Dreamliners, which has been delayed.

Meanwhile, Centre for Asia-Pacific Aviation executive chairman Peter Harbison said aviation in the region is entering 'unknown territory' with a new industry structure potentially better positioned to cope with an economic downturn.

'We are entering a tunnel - economically - and we don't know how long and deep it will go.

'A decade ago in the Asian financial crisis, the outcome was simple: people stopped flying and airlines lost money,' he pointed out.

'This time around things could be very different - we have a new aviation environment with new private airlines, mostly well-positioned to survive in difficult markets.'

rogmaynard@compuserve.com