The deal, which is subject to approval from the relevant authorities, follows a review of Orange’s operations in Kenya and Uganda in March this year.
Financial details of the takeover were not disclosed.
Africell plans to acquire Orange’s 53% stake in Orange Uganda, which will enable the company – which is already operating in the Democratic Republic of Congo, Gambia, and Sierra Leone – to expand its footprint into Uganda.
Orange has been looking to exit Uganda’s difficult market, as its Ugandan operations have struggled to compete with the country's dominant players, MTN and Airtel.
"This transaction marks a new step in the Orange group's asset portfolio optimisation strategy, for which Africa and the Middle East remain a strategic priority," said Orange.
Falling revenues due to competition could also result in the company looking to sell its operations in Kenya.
