Emirates airline has ordered 150 777X aeroplanes from Boeing for $56bn. The order includes purchase rights for an additional 50 aircraft that, if exercised, could increase the total value to approximately $75bn.

The Dubai-based airline initially announced its commitment to the purchase – a combination of 115 777-9Xs and 35 777-8Xs – at the Dubai Air Show in November 2013. In total, it has 208 Boeing 777s pending, with targeted delivery dates of 2020 onwards. Design of the 777X is under way and production is set to begin in 2017.

The agreement follows Emirates’ cancellation of 70 Airbus planes in June, a deal valued at $16bn at the time.

“The decision follows ongoing discussions with the airline in light of their fleet requirement review, as demonstrated by their order of 50 additional A380s at the last Dubai Airshow and their continuous interest in the programme,” Airbus said in a statement.

Airbus and Boeing have long been vying for greater market share in the Middle East’s growing aviation sector. Emirates’ decision could force Airbus to reconsider its product strategy and lead to costly investment in improving current aircraft models to meet the changing demands of airlines.