Nok Air's board has approved its initial public offering (IPO) and the resumption of its international services.

The endorsement last Friday set into motion the budget airline's IPO scheme, involving the divestiture of up to a 30% stake to raise 3 billion baht to fund its growth plan, chiefly for aircraft.

Its financial adviser, Siam Commercial Bank, is preparing a listing application for submission to the Securities and Exchange Commission. The IPO will most likely take place in August, said Patee Sarasin, Nok Air's chief executive.

He said while details have yet to be finalised, as much as 30% of the company will be offered, with existing shareholders' holdings reduced pro rata.

Thai Airways International has a 49% stake in Nok Air.

Meanwhile, the nine-year-old airline has decided Bangkok-Yangon will be the first route for its revived international service, with two daily flights starting in September.

The airline has not identified a second international route, but Mr Patee earlier indicated it was looking at southern China.

"We'll cautiously expand international flights in order not to repeat the mistakes that plunged us into a financial crisis several years ago," he said.

Nok Air has expanded its domestic business since 2008, when it suspended its loss-making international flights to Vietnam and India to stem the red ink.

Last month Nok Air took delivery of its 10th B737-800.

A few more of these jets are expected to join Nok Air's fleet this year, with a couple more planned for next year.

Over the next five years, Nok Air plans to operate a fleet of 40 aircraft, raising its passenger volume to more than 14 million in 2017 from 6 million last year.