AirAsia, Southeast Asia's largest budget carrier by fleet size, said Sunday it has agreed to buy 175 new fuel efficient A320 Airbus aircraft for at least 10.5 billion dollars.

"We have placed a new order of an additional 25 A320s with Airbus," Tony Fernandes, group chief executive told AFP. AirAsia had previously ordered 150 aircraft.

Each A320 aircraft carries a catalogue price of 60 million dollars.

The announcement comes on the back of the carrier being allowed to fly the lucrative Kuala Lumpur-Singapore route.

AirAsia Friday said its fiscal first quarter net profit had risen by more than 150 percent on higher passenger volume.

The carrier said net profit in the quarter ended September 30 rose to 180 million ringgit (53 million dollars), up 157.1 percent from 70 million ringgit a year earlier.

Fernandes said AirAsia had to acquire more aircraft to meet it ambitious route expansion and liberalisation of air links among Southeast Asian countries.

"Our business is also growing at a strong pace," he said.

Fernandes said AirAsia was confident it could weather the current high fuel prices, adding the "high fuel price is sustainable" and the A320s are fuel efficient.

AirAsia has already received at least 50 A320s from Airbus.