
His resignation takes effect on Tuesday. Wallop had taken leave after the airline set up a panel to investigate into an allegation that he was accused of using his position to dodge excess baggage fees.
Wallop was accused of forcing the airline to carry 30 pieces of luggage weighing a combined o170 kilogrammes free of charge, on their flight from Tokyo's Narita airport to Bangkok's Suvarnabhumi airport on November 14 last year.
They are also accused of channelling the baggage through a special route to avoid paying taxes and fees.
Wallop has denied any abuse of executive power, saying the report was politically motivated.
The permitted baggage weights for economy, business and first-class passengers are 20kg, 30kg and 50kg per person, respectively. Passengers are subject to excess charges if their permitted luggage weight is exceeded.