The Department of Airports is opposed to Airports of Thailand's plan take over Krabi airport, which is its main source of income.
DoA director-general Ampawan Wannako said on Thursday that Krabi airport was one of four regional airports that AoT now planned to take over from the department.
Earlier AoT had planned to take over and upgrade Udon Thani and Sakon Nakhon airports in the Northeast, Tak airport in the North and Chumphon airport in the upper South.
The plan later changed to Krabi, Buriram, Tak, and Udon Thani airports.
The loss of Krabi airport would cause problems for the maintenance of the 24 other regional airports run by the DoA, Mrs Ampawan said. Krabi airport provided 55% of the department's total income.
Last year the department took in 852.47 million baht from its 28 airports, and the income from Krabi airport accounted for 469.41 million baht.
Mrs Ampawan also said the takeover could mean a rise in air ticket prices, because AoT's passenger service charges and airport parking fees were higher than her department's.
The DoA was already investing 6 billion baht in expanding Krabi airport. This included a third terminal, bigger parking area and a parallel taxiway.
If the cabinet approved AoT's takeover of Krabi airport, who would fund the maintenance of the other 24 regional airports, staff, air transport services in other regions and new airport projects in remote areas, the DoA chief asked.
Transport Minister Saksayam Chidchob said on Thursday that he would discuss the takeover with the DoA and AoT. It would depend on the DoA, because it owned Krabi airport.
Deputy Transport Minister Thaworn Senneam said Krabi was a major airport in the South and served about 4 million travellers a year.