The two companies would be in exclusive talks till July 31.
"Talks are going on between Bharti Enterprises, the parent of Bharti Airtel, and South Africa's MTN Group Ltd to form a global business combination," Akhil Gupta, deputy group CEO and MD, Bharti Enterprises, said.
Gupta didn't elaborate any further.
Bharti Airtel and MTN had in May revived talks over a complex $23-billion combine that would create one of the 10 largest companies in the mobile telecom sector.
Their merger talks last year had fallen apart as they could not reach an agreement on a management structure.
If successful, the combined wireless group will have more than 200 million subscribers and a combined revenue of $20 billion.
The Indian telecom major is exploring a potential transaction whereby it would acquire 49 per cent in MTN, and in turn, MTN and its shareholders would acquire approximately 36 per cent economic interest in Bharti.
The Securities and Exchange Board of India has exempted MTN from making an open offer to Bharti shareholders. The market regulator, however, said the open offer would be triggerred only once the global depository receipts are converted into local shares with voting rights.
Image: Bharti chief Sunil Mittal. Photograph: Rediff Archives