The news comes a year after the his energy firm acquired a strategic 40-percent stake in SOLA Group.
The news comes after the group signed a three-year wage agreement with its gold mine workers.
Wanjui derives his wealth from a diversified investment portfolio.
Du Plessis co-founded Capitec Bank in 2001.
Rabiu is now Africa's fifth-richest man.
Ayed owns a beneficial 3.4-percent stake in the conglomerate.
Adenuga derives the majority of his wealth from his telecom company and his investments in the Nigerian oil industry.
The move comes nearly a year after the British energy giant announced plans to divest its interests in Nigeria.
Raya Holding is a leading brand in Egypt, with its operations generating a net profit of $34.5 million in 2021.
Hiridjee controls AXIAN, one of Madagascar's largest conglomerates.