MTN, Africa's largest mobile phone operator in customer numbers, has agreed to buy Investcom, a Dubai-based telecoms firm for $5.53bn (£3bn).
The market for mobile phones is growing fast in Africa
The takeover is set to make MTN the second-largest emerging markets mobile phone operator.
The deal will give MTN 28.1 million customers across 21 countries.
MTN head Phuthuma Nhleko said he was "delighted" with the move which "delivers the next stage in MTN Group's emerging markets growth strategy".
"This well-considered partnership entrenches our leadership in telecommunications in Africa and the Middle East," he added.
Sean Gardiner, emerging markets telecom analyst with Morgan Stanley, told the Reuters news agency that the deal was a "positive step" for MTN.
"I do not think the price is that outrageous given the amount people are paying for African assets and the potential synergies," he added.
While Africa's mobile market is still relatively small, with penetration levels of about 9%, it has been increasingly attracting African, Middle Eastern and European telecom firms who see growth potential.
British firm Vodafone recently raised its stake in South Africa's Vodacom, while Kuwait's MTC bought Celtec last year for $3.3bn.
MTN said it was offering $3.85 a share for Investcom, and would also offer a cash and shares alternative.
Lebanon's Mikati family, which holds just over 70% of Investcom, has given the go-ahead for the deal.