New Delhi, Jan. 12: India’s low-cost carrier IndiGo has placed a giant provisional order for 180 Airbus A-320s — billed the biggest for jets in commercial aviation history.

The aircraft deal is worth $15.6 billion (about Rs 70,200 crore) but sources said the budget carrier had been able to wrest a 5-8 per cent discount on the list price from Toulouse-based Airbus Industrie.

Under the terms of the deal, IndiGo will get 150 new-generation A-320 called the Neo, which has special wingtips designed to reduce fuel consumption by 15 per cent, muffle engine noise and slash emission of nitrogen oxides.

It will be also buying 30 traditional A-320s, which serve as the workhorses of airlines in medium-haul segments.

The classic Airbus A-320 had a list price of $81.4 million in 2010. The Neo is expected to cost about $6 million more.

“This order for fuel-efficient aircraft will allow IndiGo to continue to offer low fares,” said Rahul Bhatia, the group managing director of InterGlobe Enterprises that owns the airline along with Rakesh Gangwal, a former chief executive of US Airways.

In 1998, Gangwal had firmed up orders for 400 Airbus planes for US Airways —and the IndiGo deal rekindles those memories. Gangwal quit the airline in 2001.

The deal announced today is the biggest in aviation history by number of planes with more than 100 seats, Airbus said.

The agreed purchase underlines India’s development as a major aviation market and provides a welcome boost to Airbus parent EADS’s chief executive Louis Gallois, who has been pushing expansion into emerging markets as traditional markets falter. It also gets an early blow in for the European Airbus in the annual battle with US rival Boeing for sales supremacy.

Airbus had launched the A-320 Neo in December but this is the first big endorsement from any airline.

The aircraft comes with a choice of engines and IndiGo will have to choose between Pratt & Whitney, a unit of United Technologies, and CFM International, which is jointly owned by General Electric and French group Safran.

IndiGo will decide on the engine and its payment options for the new planes later. The airline has a pending order with Airbus for 100 A-320s. The Airbus website shows that it has already delivered 37 planes. The rest will be delivered by 2015.

IndiGo president Aditya Ghosh told reporters that the airline would consider all options to finance the new order.

The airline plans to come out with its maiden share floatation later this year to raise Rs 2,500 crore. A part of this money will be used to pay for some of the planes to be delivered against the earlier order.

IndiGo already operates a fleet of 34 Airbus A-320 planes that offer 221 daily flights to 24 destinations. Last year, it overtook Air India by carving out a domestic market share of 17.3 per cent.

The new planes will be delivered only after 2016 and will be deployed on domestic as well as international routes.

IndiGo has already received regulatory approval to start international operations from September and intends to fly to the Gulf, South Asian and South East Asian destinations.

“These are routes tailor-made for A320s — where the flying time is about 4-5 hours and there’s heavy demand from tourists and business travellers,” said Robin Pathak, former Indian Airlines director and industry consultant.

IndiGo will face stiff competition on these routes from Indian carriers like Air India, Kingfisher Airlines and Jet Airways as well as a gaggle of low-cost Asian airlines: Air Arabia, Air Asia, Jazeera Air and FlyDubai, which have already carved out fairly large market shares.

The IndiGo deal will put pressure on Seattle-based Boeing Co and Canada’s Bombardier, which have also been scrambling to sew up deals.

Indian Airlines, Jet Airways and Kingfisher Airlines have placed orders with Airbus. SpiceJet had announced orders for 30 Boeing 737s and 30 Bombardier turboprop planes.

“None of these airlines have great balance sheets. Still, they are placing orders for jetliners because Indian aviation is growing at a rapid 20 to 25 per cent, fuelled by growing per capita income and the need for faster connectivity. This sort of growth rate will continue into the next decade,” said Pathak.

Analysts and bankers say there is nothing wrong in betting on future revenue streams while expanding a fleet. India currently has about 400 commercial airliners.

Most domestic airlines tumbled into the red in the past few years when the global downturn hurt airline revenues. IndiGo has since clawed back and reported a net profit of Rs 510 crore for the year ended March 31, 2010.