SINGAPORE - BUDGET airlines began flying the Singapore-Kuala Lumpur route on Friday, ending 30 years of dominance by the national carriers and opening the way for wider liberalisation of the region's air corridors.

Malaysia-based AirAsia, which pioneered regional low-cost travel more than six years ago, was the first to enter the sector, with a morning departure from Kuala Lumpur.

The flight arrived at 10.43am Singapore time - about 12 minutes early - at Singapore's Changi Airport, where official speeches and a ceremony had been laid on to welcome the passengers.

AirAsia's chief executive Tony Fernandes battled for six years to be allowed to fly between Singapore and Kuala Lumpur.

His carrier will operate two flights a day on the route, after authorities announced in November they were opening it up to low-cost carriers.

From next month, there will be four budget flights a day in total.

Singapore-based Tiger Airways and Jetstar will have one daily flight each on the route, which Singapore Airlines and Malaysia Airlines had dominated since 1972.

Travellers preparing to board the first budget trip out of Singapore, a Tiger Airways flight leaving at 10.50am Singapore time, welcomed the lower fares.

'It's a short trip, but it was cheap, so we just decided to take a flight there,' said Mr Jaiakumar Siwan, a Singaporean travelling with 20 family members to see a visiting spiritual adviser from India.

Budget carriers have set the tone for competition by offering big discounts - including some seats priced at zero dollars before taxes - to inaugurate their new services.

Singapore Airlines and Malaysia Airlines have charged almost S$450, including taxes, for a round trip.

Mr Jaiakumar said the travellers in his group paid S$150 each for a return ticket.

Malaysian human resources consultant Hannif Khoo, 33, heading home for the Lunar New Year, said he had decided to fly after leaving it too late to get a bus seat.

He said he paid S$290 for four people to fly, adding, 'I noticed there were still seats, so I booked it.'

A one-way bus trip to Kuala Lumpur takes around five hours and costs between S$28 and S$55, including a meal and drinks - which cost extra on the low-cost airlines.

Mr Peter Harbison, executive chairman of the Sydney-based Centre for Asia Pacific Aviation consultancy, said it was hard to overstate the importance of opening the sector, given the benefits to consumers as well as to both nations' economies.

'This (has been) one of the most obvious bastions of protectionism in the region,' he said.

Mr Fernandes said Friday would be 'a liberation day for the Asian aviation industry'.

Tiger is 49 per cent owned by Singapore Airlines, while Jetstar is the budget offshoot of Australian flag carrier Qantas.

By December the route will be fully liberalised under a pact by the 10-member Association of Southeast Asian Nations (ASEAN) to remove all restrictions on passenger flights between regional capitals.

Malaysia and Singapore are members of ASEAN.

Gearing up to defend their turf, the two flag carriers expanded an existing codeshare agreement to include all services between Singapore and Kuala Lumpur.

Starting on Monday, the move gives travellers a choice of 13 daily flights on the two airlines.

A Singapore aviation official said the KL-Singapore shake-up would likely herald further competition in the region's skies.

Mr Yam Kum Weng, a senior director with the Civil Aviation Authority of Singapore, called it 'a wave that will sweep the entire region.' -- AFP