A court on Tuesday dismissed a 14 billion baht graft case against Airports of Thailand and duty-free retailer King Power, owner of the English Premier League club Leicester City.
A former anti-graft official, Chanchai Aitsarasenalux, had in a private capacity sued executives from both firms last year.
He accused King Power of failing to pay the Thai government 14 billion baht from the operation of an airport franchise it was granted in 2006.
Airports of Thailand, which is 70%-owned by the Thai government, and King Power had denied the allegations.
A judge at the Central Criminal Court for Corruption and Misconduct Cases said on Tuesday Mr Chanchai "was not an affected party, therefore he cannot sue in this case."
Mr Chanchai told reporters that he will appeal within 30 days.
King Power was granted the duty-free concession in 2006 by the government of then-Prime Minister Thaksin Shinawatra. The franchise is set to expire in 2020 with Airports of Thailand due to hold an auction this year for the license.
King Power is owned by billionaire Vichai Srivaddhanaprabha and his family.
The family's empire also includes Belgian football club, Oud-Heverlee Leuven, Accor's Pullman hotels in Thailand and stakes in Asia Aviation Plc, AirAsia Group Bhd's partner in budget carrier, Thai AirAsia.