Mumbai, June 19 (PTI): Budget carrier SpiceJet today signed an initial pact with the US aircraft maker Boeing Co for 40 737 MAX planes.

A memorandum of understanding valued at $4.7 billion at current list prices was signed at the Paris Air Show, which commenced today.

The agreement is split evenly between 20 new orders for the 737 MAX 10 and the conversions of 20 737 MAX 8 airplanes from the airline's existing order to 737 MAX 10s, according to a release.

"As a Boeing 737 operator and current customer of the 737 MAX, we are proud to be part of the launch of the 737 MAX 10 and to be the first airline in India to order the newest version of the 737, which will enable us to maximise revenue on our dense routes while having a lower unit seat cost," SpiceJet chairman and managing director Ajay Singh said in a release.

"With the introduction of our 737 MAXs next year, we will be able to further expand our network, while keeping our costs low for our customers," Singh said.

The Gurgaon-based no-frills airline had earlier this year announced that it will purchase up to 205 new aircraft (including 55 from the 2014 order) from Boeing with the order valued at $22 billion.

SpiceJet currently has a fleet of 55 planes.

"SpiceJet continues to be an aviation leader and strong Boeing partner, and we are honoured to have them join 737 MAX 10 launch group," Boeing commercial airplanes president and chief executive officer Kevin McAllister said.

"The additional 20 737 MAX 8s and capacity provided by these 20 new 737 MAX 10s will allow SpiceJet to offer even more passengers their award-winning on-board experience, while the airplane's efficiency will keep SpiceJet profitable," he said.

Boeing claims the MAX 10 will be the most efficient jet yet. The 737 MAX 10, which can carry up to 230 passengers, is the largest in the class, and Boeing said it would be 5 per cent cheaper to operate than the Airbus A321neo.

As these planes can carry more passengers, they have attracted interest from low-cost airlines as well as carriers looking to exploit their range that allows them to make flights across the Atlantic. McAllister said the 737 MAX 10 would "the most efficient single-aisle airplane in the skies".

SpiceJet is scheduled to take the delivery of its first 737 MAX in 2018. The carrier plans to grow its operational fleet to 200 planes by the end of the decade.