Air One, the airline based in Rome, Italy, has ordered 24 aircraft from Airbus Industrie, the aircraft-manufacturing consortium based in Toulouse, France.

The airline is buying the 24 planes at a cost of $4.8 billion to expand its long-haul flights the United States and the Far East.

Air One, Italy’s second largest airline after Alitalia, also has an option to buy another 20 planes for about $3.8 billion.

As for Airbus, the deal with Air One is the second major order in just one week after Gulf Air, the flag carrier of the Kingdom of Bahrain, placed an order worth $4.5 billion for 35 single-aisle and wide-bodied aircraft.

Air One already operates a high-frequency domestic scheduled network to about 25 destinations and international services to several cities in Europe. It serves regional destinations under the name Air One CityLiner with the brand-new fleet of Canadair CRJ-900 planes, according to a statement from Air One.

The 24 Airbus planes that Air One has ordered consist of 12 A330s and 12 A350s. The A330s will be delivered by 2012, and the A350s by 2018.

Air One says it expects to offer flights to 50 destinations by 2012, and will offer flights to Boston and Chicago in the United States from Milan, Italy, later in June 2008.

The airline has been building up its operations even as Alitalia, the state-controlled national carrier of Italy, is losing market share and is on the brink of bankruptcy.

Guardian newspaper reported  that Air One, which has a 37% share of the Italy’s airline market, is expected to be a member of a group of investors that the Italian government of Prime Minister Silvio Berlusconi is trying to enlist for a new bid for Alitalia.

Carlo Toto, chief of Air One, was quoted as telling the media that his airline was still interested in buying Alitalia, the Italian flagship carrier and but would not say if it would be part of a bidding group.

Alitalia had earlier rejected a bid by Air One, Alitalia’s biggest competitor, in favour of a  bid by Air France-KLM – the largest airline company in the world in terms of total operating revenues, and the third largest in the world in terms of passenger-kilometres.

However, Air France-KLM withdrew its bid in April 2008 owing to opposition by unions as well as political pressures.

A  statement from Air One says that the airline is planning to increase the number of flights out of Malpensa international airport near Milan, Italy – with the eventual goal of becoming Malpensa’s main airline. At the same time, Alitalia has reduced its presence in Malpensa with a view to cutting costs and has instead focused on its hub in Rome.