China-owned plane-leasing company BOC Aviation said Tuesday it has ordered 50 Airbus aircraft of the medium-haul A320 family, including 25 of the more fuel-efficient "neos".

The statement did not disclose the value of the deal, but price tags in the 2012 catalogue ranged from $4.41 billion (3.3 billion euros) for 50 classic A320s to $5.66 billion for 50 A321neos.

Customers placing large orders, however, are typically able to secure substantial discounts on the list price.

BOC Aviation said an announcement on the exact make-up of the order, which is scheduled for delivery between the second half of 2014 and the end of 2019, would be made later.

The order was the first by BOC Aviation for Airbus's new engine option.

Robert Martin, BOC Aviation's managing director and chief executive officer, said the firm was keen to offer its clients the latest energy efficient aircraft, explaining the presence of the new neo engine option in the order.

The A320neo series is designed to reduce emissions and cut fuel consumption by up to 15 percent.

"The announcement from BOC Aviation is another vote of confidence in the long-term appeal of our popular A320 Family," said John Leahy, Airbus's chief operating officer -- customers.

The company said that to date, more than 8,800 aircraft from the A320 series have been ordered and some 5,300 delivered to 380 customers and operators worldwide.

The plane competes with Boeing's 737 airliner, of which a 737 MAX version is scheduled for launch in 2017.

Airbus said last week that Irish aircraft leasing group Avolon had confirmed an order for 20 A320neo jets.

And on Monday it said that Citilink, the low-cost branch of Indonesian airline Garuda, had ordered 25 A320neo aircraft.

Airbus is to release its annual results on Thursday, and sector analysts said this week they expected the company to unveil additional orders before then.

In early December, the European aircraft manufacturer said it had received a net number of orders, after accounting for cancellations, for 585 planes last year up to November 30.

Meanwhile Boeing reported a total of 1,203 net orders last year.

BOC Aviation, which is owned by the Bank of China but based in Singapore, owns or manages 203 aircraft operated by airlines worldwide with another 100 planes on firm order.

The firm says it has one of the youngest fleets in the industry with an average aircraft age of less than four years.