AFTER years of double-digit growth, the rate of acquisition of new subscribers in the African mobile telecommunications market has sharply decelerated, according to research firm AT Kearney.

Africa is the last frontier for the telecoms industry and has been attracting significant interest and investments, the company said in a report last week.

Significant investments by local companies MTN and Vodacom and global groups such as Vodafone, France Télécom and Bharti Airtel have boosted their profits.

Africa had more than 730m mobile subscriptions, corresponding to a SIM-card penetration rate of more than 65%, and total revenues of $40bn, said AT Kearney, adding that adoption of mobile services had been fuelled by increased network coverage and lower prices for services and handsets.

But since last year, growth in mobile penetration seemed to have "abruptly decelerated", with subscriber growth rates now in single digits in most countries, said Laurent Viviez, partner and head of the African telecoms practice at AT Kearney.

Industry observers attribute the reduction to factors including a tougher economic climate in some countries, prices that remain unaffordable levels for the more modest socioeconomic segments, and penetration rates gradually approaching saturation levels.

"While all these facts are certainly relevant, they are in our view partly misleading," said Mr Viviez. "Multi-SIM ownership, which stands at 30%-50%, means that real penetration rates are in reality closer to 35%. Also, the abrupt deceleration in subscriber growth in 2011 is to a significant extent explained by the implementation of mandatory subscriber registration in a number of countries."

But the African telecoms market still offered ample room for growth, he said. Further adoption of data and internet services, still in their infancy, would provide additional momentum to the development of telecoms in Africa.

AT Kearney believes the market will shift from a focus on "upper classes and (being) largely voice-centric to a mass market" with a much more significant share of data services.

"We believe that in the next 10 years... Africa will face a digital revolution, enabled by ubiquitous and affordable access to internet services," said Mr Viviez.