Singapore-based aircraft leasing firm BOC Aviation said on Friday it has ordered six new Airbus planes worth around 1.05 billion.

The order comprises four planes from the A320 NEO family and two Airbus A330-900 aircraft, the leasing company said in a statement.

"All six Airbus aircraft have been committed for lease to Portugal's flag-carrier TAP Portugal and will be delivered between 2018 and 2020," BOC said in a statement.

Steven Townend, chief commercial officer for Europe, the Americas and Africa at BOC, said the deal with TAP Portugal "represents yet another new European customer" that will help it further expand its portfolio.

TAP Portugal vice president for finance Teresa Lopes said the airline's fleet renewal plan includes "53 brand new" Airbus NEO aircraft.

BOC Aviation, owned by Bank of China, is based in Singapore with offices in Dublin, London, Seattle and Tianjin.

It is a key customer for both Airbus, based in France, and US rival Boeing.

In January last year, it announced an order for 30 Airbus A320s worth more than 3 billion to meet growing demand.

In March this year, it announced an order for 13 new Boeing 737 MAX 8 planes worth a total of 1.4 billion. This was on top of an order announced in November 2015 for 22 Boeing 737 planes worth 2.27 billion.

The single-aisle A320 and B737 families are popular choices among low-cost carriers.