The Kuwaiti leasing group will sell the planes to Saudi Arabia’s national carrier from 2014.
Alafco also revealed it will lease four more of the same aircraft to Saudia from 2012, and five short-haul Airbus A320-200 for eight years starting in 2009.
Alafco says the value of the two leasing contracts is $1.1bn at list prices.
The leasing company announced in December last year that it planned to increase its fleet of 18 planes to 100 aircraft within a decade. The company has confirmed orders for 66 new aircraft.