The deal, signed on the opening day of the Singapore Airshow, also covers rights to acquire or lease 38 more A320s, potentially boosting the budget carrier's current fleet of 11 A320s tenfold.

"The A320 has proven to be extremely efficient in service with VietJetAir and is a favourite with our passengers," the firm's managing director Luu Duc Khanh said in a press statement issued by Airbus.

The Vietnamese airline, founded only in 2011, plies domestic routes as well as services to Bangkok, Seoul and Kunming in China with its current fleet of leased planes.

"We look forward to developing our business across the Asia Pacific region," Luu said, adding that Airbus would be a "strategic partner" in its regional expansion.

Fabrice Bregier, the president and chief executive of Airbus, said the order "reinforces the A320 family's position as the preferred choice in the single aisle market, both for full service and low cost carriers."

"We look forward to working with VietJetAir as it brings ever more affordable air travel to the fast growing South East Asian market," he said in the statement.

In addition to the 63 A320s on firm order, VietJetAir has rights to buy 30 more and lease another eight from third parties for a total of 101 new planes.

'Rising star'

Bregier said at a media briefing that the carrier may need even more orders because of the explosive growth in passenger traffic in Vietnam.

"In Asia, we expect a (passenger traffic) growth year-on-year of close to 6.0 percent for the next 20 years. In Vietnam, it will be close to 30 percent year-on-year. This is really impressive."

He described VietJetAir as a "rising star" in Southeast Asia's low-cost carrier market.

There have been more than 10,100 orders and 5,900 deliveries of the A320s since it hit the market to over 300 customers and operators, making it the world's best-selling single-aisle aircraft, according to Airbus.

Nguyen Thanh Hung, VietJetAir vice chairman, said that in just two years of operation, the airline already has 26.2 percent of the domestic market and has carried 4.3 million passengers.

The carrier says that on average it fills 90 percent of all available seats.

Chu Viet Cuong, a member of VietJetAir's board of directors, told AFP the airline will fund the purchases with money arranged by international financial institutions.

French bank BNP Paribas will arrange financing for the first three aircraft deliveries, he said.

Airbus, in a long-term forecast for the industry, said the Asia-Pacific region will lead the global demand for aircraft over the next 20 years.

Airlines from the region will take delivery of 10,940 passenger and cargo planes with a value of $1.8 trillion in the same period.

This will represent 37 percent of all new aircraft deliveries, Airbus said in a statement.

The passenger market fleet of Asia-Pacific carriers is forecast to more than double from 4,960 planes currently to over 12,130 aircraft by 2032.

Its US rival Boeing earlier said the Asia-Pacific will require almost 13,000 new airplanes worth $1.9 trillion over the next 20 years.

Myanmar's national carrier Myanma Airways earlier Tuesday signed a deal to lease 10 Boeing aircraft worth nearly $1 billion as the once-reclusive country opens up to the world.

The total value of deals during the biennial Singapore Airshow's 2012 edition reached $31 billion, up threefold from 2010, organisers said.