Bangkok's Don Muang airport reopened for domestic flights without a hitch on March 25, six months after it was shut down, promising to ease congestion at the city's new US$4 billion (HK$31.2 billion) airport.

Three airlines returned to the 93-year-old Don Muang, which in 2005 handled more than 38 million passengers and 160,000 flights, but airport authorities are considering plans to make it an international airport again.

State-run Airports of Thailand said those plans could delay by a few years the expansion of Suvarnabhumi airport, which opened last September and is expected to reach its full annual capacity of 45 million passengers this year.

"Moving some passengers to Don Muang is better than putting up an immediate investment of 47 billion baht (HK$10.6 billion) for the new phase of expansion," AOT acting president Kulya Pakakrong said referring to a new cost of almost US$1.5 billion for Suvarnabhumi.

"We will take six months for the study, which will recommend how we want to utilize Don Muang, for instance requiring all the low-cost airlines to come here or making it for regional flights," Kulya said.

Suvarnabhumi, which means "Golden Land" in Thai, is Southeast Asia's largest airport, and Thailand had hoped it would emerge as a serious regional rival to Hong Kong and Singapore.

But the military-appointed government decided in February to reuse Don Muang after repair works at Suvarnabhumi's runways and taxi-way caused congestion and disrupted flights.

Only national carrier Thai Airways, its low-cost arm Nok Air and another budget airline, One-Two-Go, decided to return to Don Muang. Others said they preferred to operate from the new airport because it handled both international and domestic flights.

Many passengers were pleased to return to Don Muang, which is expected to handle 140 flights and an estimated 18,000 passengers a day.

"I like this one, the new one is so big and you have to walk very far," Dutch tourist Kelly Vandersteeg said.

But Hideaki Komiya of Japan was not happy. He and his family had to take a 60-kilometer taxi ride to Don Muang after landing at Suvarnabhumi to connect to a flight to the resort island of Phuket.

"The long-term vision should still be to have all commercial flights operating out of one airport in order to build a strong hub," International Air Transport Association spokesman Albert Tjoeng said.