Bharti and MTN had revived merger talks in May, a year after previous talks broke down over who would control a merged entity. A merger would create an emerging markets giant with more than 200 million customers across India, Africa and the Middle East.

The exclusive talks over the deal, which would see each firm pay cash and stock for a stake in the other, were due to end on July 31. Sources earlier told Reuters the talks were likely to be extended by at least two to three weeks.

Under the initial terms, MTN and its shareholders would take 36 percent economic interest in Bharti Airtel and the Indian firm would end up with 49 percent of MTN.