The investment values the fintech business at $5.2 billion, implying about a 3.8% stake, with the mobile operator first announcing the proposed deal in August.

Banks and financial services providers have been eyeing the massive potential of teaming up in Africa in order to tap into a youthful population that is rapidly growing, with new technologies offering the prospect of bridging gaps in access to financial services.

MTN said on Tuesday that the agreements complement the larger commercial relationship between the group and Mastercard to support the continued development and growth of technology and infrastructure.

"This commercial relationship is a key enabler for the acceleration of our fintech business' payments and remittance services," it said.

MTN, valued at about R176 billion on the JSE, has been looking actively for strategic partners for its fintech business, looking to sell up to 30% of it. Fintech includes its mobile money (MoMo) platform, insurance, airtime lending and e-commerce, and it contributed just under a tenth of the group's R113 billion in its first half to end June.

Mastercard is publicly valued at more than R8 trillion, and it operates in more than 200 countries and territories.