[meridiasas]

Suvarnabhumi Airport's position in the latest global rankings plunged this year, widening the gap between Thailand's gateway and benchmark airports like Singapore's Changi and Hong Kong International Airport.

Bangkok's main airport was 25th in a survey conducted by Skytrax, a UK-based aviation consultancy. It was 13th last year.

The results were based on 12 million passenger surveys; 388 airports were covered.

Suvarnabhumi finished 10th in the sub-category of airports handling 30-50 million passengers annually, a new sub-category created by Skytrax.

According to Skytrax, the survey evaluated the total passenger experience across 39 airport services and features. It covered everything from arrival at the airport _ through transit and departure _ to boarding.

While Skytrax did not provide details on the latest rankings, the results of a 10-month survey that began in July 2011, industry analysts said complaints about the long immigration queues and delays in take-offs and landings, some of the problems resulting from the airport's overcrowding, dragged Suvarnabhumi's position down the rankings.

The downgrade also came as other airports continued to make improvements and as a result advanced up the list.

Suvarnabhumi's overcrowding has been worsening as the airport has been stretched beyond its capacity of 45 million passengers a year over the last two years, making it one of Asia's most congested airports.

Passenger throughput last year was 47.2 million, and the numbers are expected to soar to 51 million this year as the long-awaited expansion, that will raise passenger handling capacity to 60 million a year, is still six years away.

South Korea's Incheon International Airport was voted the world's best this year, the second time that it won the top award, the last time in 2009.

Singapore's Changi Airport finished second in the challenge for World's Best Airport title. It was rated Best Airport for International Transit Passengers and Best Airport for Leisure Amenities.

Hong Kong International Airport, eight-time winner of world's Best Airport award, secured third place this year.

Hong Kong, however, received the Best Airport Dining Experience award and Best Airport Terminal Cleanliness award, Skytrax noted.