Shareholders in International Airlines Group have backed the purchase Boeing and Airbus aircraft worth $17 billion to upgrade the fleets of British Airways and Spanish low-cost arm Vueling.

Investors approved the addition of long-haul and narrow-body aircraft by “a sufficient majority” at an extraordinary meeting in Madrid, with more than 99% of votes cast backing each resolution.

BA, which this month began regular services with Boeing 787 Dreamliners and Airbus A380 superjumbos, is adding further aircraft to replace older models.

Investors were asked to back orders for 18 more Dreamliners and 18 A350s, plus 62 A320s for Vueling, including 32 re-engined A320neos.

The additional Dreamliner order includes at least 12 of the largest 787-10s on offer from Boeing since June. The rest will be 787-9s, the mid-sized variant.

Deliveries will start in 2017, with the A350-1000s following a year later and all 36 long-haul aircraft in the BA fleet by 2021.

Barcelona-based Vueling should see its fleet grow to 125 aircraft by the same date.