The Bangkok Post reported aviation experts as saying that the city's Suvarnabhumi Airport may suffer after Singapore officially opened the US$1.22 billion (S$1.75 billion) Terminal 3 (T3) on Wednesday which will raise Changi Airport's handling capacity to 70 million passengers a year.

The 155 billion baht (S$7.5 billion) Suvarnabhumi is still plagued by operating troubles and construction flaws stemming from its premature opening in September 2006.

And the trouble is only set to get worse. Crowding problems will likely reach a critical point this year when the airport hits its designed capacity of 45 million passengers a year, the Bangkok Post said.

Furthermore, the plan to expand Suvarnabhumi remains unclear. The government has been unable to spell out a clear policy on whether the old Don Muang Airport should also handle international traffic to relieve congestion at Suvarnabhumi.

'If an airport doesn't have the capacity to accommodate growth, airlines and passengers will end up going to an airport that has this capacity. Singapore is ready to handle the additional passengers,' the International Air Transport Association (Iata) said.

T3's opening will enhance Changi's position as the region's air hub, enabling it to meet the 5.9 per cent annual growth rate anticipated in the Asia-Pacific region between 2007 and 2011.

That translates into 300 million additional passengers in Asia over the next five years, noted Mr Albert Tjoeng, Iata's Asia-Pacific spokesman.

Airports in Asia need to continue planning and investing in additional capacity to keep pace with expected traffic growth and ensure that the capacity is efficiently utilised, said the Geneva-based organisation.

However, Mrs Kulya Pakakrong, a senior executive vice-president at Airports of Thailand Plc (AoT), downplayed the impact of Changi's expansion on Suvarnabhumi.

'Airlines and passengers going to Singapore represent different market groups, mostly involving corporate travellers, while those coming to Thai airports are largely tourists,' she said.

'It is those passengers who cause airlines to fly to Bangkok,' she added, noting that the state-controlled airport monopoly kept a careful eye on what its regional competitors were up to.