As a state agency, THAI racked up about Bt250 billion in debts before asking for court-supervised restructuring earlier this year.
The Transport Ministry panel found THAI had sold discounted tickets to agents, resulting in losses of billions per year.
According to Komkit Wongsomboon, who heads the panel, the corruption involved incentives for ticket-sellers based on the volume of tickets sold rather than their value or resulting sales deficit.
More evidence of graft was found in the maintenance department, where the hourly overtime rate of Bt1,500 was inflated to Bt2,000-Bt3,000 for 200 to 300 workers, resulting in losses totalling Bt2 billion a year.
The panel also seized on the disastrous decision to buy 10 Airbus 340s for about Bt100 billion from 2004. Rising maintenance costs meant the company lost money on all 10 jets, nine of which lost value after being decommissioned and stored at U-Tapao Airport.