The stake was sold by Abraaj Capital, a Dubai-based private equity firm backed by Saudi investors including Sheikh Abdulrahman Ali al-Turki.

Abraaj says its investors made a 52 per cent internal rate of return from the deal, although it has not revealed the value of the sale.

Kingdom’s acquisition increases its stake in the group to 39 per cent following the purchase of a 9 per cent holding in NAS last November for SR262m ($69.7m), a deal which valued the airline at SR2.9bn.

Nas' operations include private aviation services, as well as Nas Air, a low-cost carrier which launched early last year.