By Joe Brock, Tim Hepher, Giulia Segreti and Paul Sandle PARIS (Reuters) - Airbus struck a deal with budget airline VietJet for up to 150 single-aisle jets at the Paris Airshow on Tuesday, where industry hopes for a return to tariff-free trade were given a boost by U.

Boeing's CEO pulled out of the Paris Air Show following the Air India crash, which has set a somber mood for the aviation and defense event at Le Bourget.

Airbus dominated the first day of the biennial Paris Air Show, unveiling close to $10bn of orders after its rival Boeing cut back its activities following last week’s fatal Air India crash .

The companies said they had signed a memorandum of understanding for VietJet to buy 100 more A321neo planes, with the option to add up to a further 50 to the deal in future. The agreement confirmed an earlier Reuters story. A deal for 150 A321neos could be worth around $9.4 billion, according to estimated prices provided by Cirium Ascend.

European aeroplane manufacturer Airbus announced Saudi and Polish orders for more than 100 aircraft at the Paris Air Show on Monday while US rival Boeing f

Airbus SE predicted the global commercial aircraft fleet will double in size to almost 50,000 planes over the next 20 years, spurred by rapid growth in markets like India, where a rising middle class increasingly takes to air travel.

Airbus bagged multibillion-dollar plane orders from Saudi Arabia and Poland on the opening day of the Paris Airshow clouded by a separate diplomatic dispute over France's decision to shut down some Israeli stands for displaying deadly weapons.