The airline has also launched a campaign offering 20 per cent discounts on domestic fares during May and June.
THAI president Piyasvasti Amranand said the airline would revise its flight network and aircraft types to address several issues, including cancellations following the volcanic eruption in Iceland and the temporary closure of European airports.
Moreover, the airline is also suffering from travel warnings issued by 47 countries due to the ongoing political unrest.
"The number of passengers has dropped during the annual low season of May and June, though the cabins were 72 per cent full last month. However, we still want to adjust our routing network and fleet over May and June," said Piyasvasti.
According to Chokchai Panyayong, executive vice president for strategy and business development, THAI will reduce its flight frequency on the Bangkok-Athens route from four to three flights a week and change the aircraft type from Boeing 777-200 to Boeing 777-300. These changes will be implemented from June 1.
For India, THAI will reduce its flights to Mumbai from 10 to seven a week from May 16 and will change the aircraft type from Boeing 777-300 to Boeing 777-200. Smaller aircraft will also be used for the Bangkok-New Delhi route.
The airline is also changing its aircraft on the Bangkok-Dubai route from Airbus A340-600 to Boeing 777-200.
Chokchai added that the airline would promote the Jakarta-Europe via Bangkok route by increasing the number of flights between Bangkok and Jakarta from seven to 14 a week. The move is to serve passengers between Indonesia and Europe as well as Indonesia and India. The number of flights from Bangkok to Bali will also be doubled to 14 a week.
THAI is also temporarily suspending its Bangkok-Sydney-Brisbane route but is increasing its Bangkok-Brisbane flights from three to five a week and the Bangkok-Auckland flights from four to five a week.
Meanwhile, Pruet Boobphakam, executive vice president for the commercial department, said the airline was hoping to reclaim passengers by offering a 20 per cent discount for domestic routes during May and June.
The airline has already received advance bookings of 66 per cent, but is still hoping to gain 70 per cent bookings during the low season. The airline was 81-per-cent booked in the first quarter.