Thai Airways International appears to be moving ahead with plans to expand its fleet and, at the same time, is upping its takeover bid for Nok Air.

It is trying to buy Krung Thai Bank’s 10% stake, after which it will own 49% of Nok. Thai has increased its bid to 32-33 baht ($1.04) per share from 13 baht, says Thai VP-Investor Relations Raj Tanta-nanta, adding, “We have to now pay a premium because Nok has since become profitable.” Krung Thai has said in the past it wants 44 baht a share. Krung Thai’s price values the airline at $72 million, whereas Thai’s earlier offer valued it at $21 million, and its latest offer values the business at $53 million.

Thai wants Krung Thai’s stake because this will give Thai enough leverage to get a fifth board seat, says Raj. The airline has nine board seats, so Thai moving to five will give it greater control over the airline, he says.

If Nok fails to work in accordance with Thai’s interests, then Thai may establish a value-based airline of its own, says Raj. This would be a separate initiative to Thai Tiger, which is a low-cost carrier that Thai is establishing this year with Singapore’s Tiger Airways.

Raj says Nok is a value-based carrier and cannot be called a low-cost carrier because its aircraft are in a two-class configuration, it offers free food and drinks and has an extra baggage allowance.

Thai Tiger, meanwhile, aims to start this year but its application is now bogged down at the transportation ministry. The country’s prime minister and finance minister support the establishment of Thai Tiger, but the transport minister is against it.

Raj says it is likely that Thai Tiger’s launch will be delayed until June. It was aiming to launch in May.

In a separate development, Thai’s board has granted approval for Thai to acquire 37 aircraft during the 2011-2017 period. This is in addition to the seven Airbus A330s, eight Boeing 777-300ERs and six Airbus A380s it already has on order, says Raj. He says the 37 will include leased aircraft. Thai has traditionally bought aircraft and relied very little on leases, but that is changing.

The 37 aircraft will also include 11 narrowbodies–either A320s or 737s–while the others will be widebodies, says Raj. “Mid-year, there will be a first indication of the final decision” on the narrowbodies, he says.

Widebodies in contention are Airbus’s A330, A350 and A380, and Boeing’s 777, 787 and 747-8.

The 37 aircraft are likely to include some A330s and 777s because these two types have become the mainstay of the fleet, says Raj. He says Thai needs more widebodies right now for its services to Europe and it might have been a mistake to push back its A380 delivery slots. Thai’s first three A380s were originally due to be delivered this year, but it delayed delivery to the later part of 2012, he says. The other three are to be delivered in early 2013, he adds.