Deputy Transport Minister Gen Prin Suvanadat said flights should return to normal at 9am on Wednesday after the surface of the eastern runway is repaired and the stricken aircraft removed from the site.
Part of the runway has been closed since the crash on Sunday and is open only to small aircraft. Up to 30 minute delays on outbound flights and 15 minute delays on incoming flights are expected until the entire runway is back in service.
THAI flight TG679 skidded off the runway about 11.20pm on Sunday after leaving Guangzhou in China at 8.25pm Thailand time. It was carrying 287 passengers and 14 crew.
The crash injured 14 passengers, 12 of whom have already been released from hospital. A 60-year-old Chinese national and a Zimbabwean national are still being treated at Samitivej Srinakarin Hospital.
Airport officials attempted to paint over the Thai Airways International logo and branding on the crashed plane as it lay at the site of the incident.
Airports of Thailand Plc (AoT) board chairman Sita Divari said a malfunction affecting the plane's right-hand side landing gear was to blame for the accident. The problem occurred after the plane had landed, and caused one of the aircraft's right tyres to burst. The plane then travelled for 300 metres before veering off the runway, he said.
The cost of damage to the runway was around one-million-baht, for which THAI would have to take full responsibility, he added.
At least 106 flights were delayed on Monday afternoon as a result of the incident.
AoT will ask Don Mueang airport in Bangkok and U-tapao airport in Rayong to take on extra flights if the situation worsens.
The national carrier and the Department of Civil Aviation have meanwhile set up separate panels to investigate the crash.
The crashed plane had been in service for 18 years. Its last routine check was in April this year, according to THAI president Sorajak Kasemsuvan. The pilot who was in charge of the aircraft at the time of the crash has 14 years of experience, he said.
The national carrier will pay luggage delay compensation of US$200 to business class passengers and US$100 to economy class customers travelling on the flight, he added.
Mr Sorajak said the captain and air crew did their best to help the passengers, most of them Chinese tourists, after the accident. He defended the airport's decision to obscure the THAI logo on the damaged aircraft as normal procedure.
Former independent candidate for Bangkok governor Kosit Suvinitjit was one of the 288 passengers on board the flight.
He told FM100.5 that the aircraft landed smoothly at first, but then veered to the right, accompanied by a loud noise. "I looked out of the window and saw two parts of the plane removed," said Mr Kosit, who was sat in the business class section. "I saw smoke and then heard the captain ordering an emergency evacuation."