Congo Republic complained on Monday it had not been informed of Bharti Airtel's $9 billion deal to buy Kuwaiti telco Zain's African assets in what it said was a contravention of Zain's licence.
Telecoms Minister Thierry Moungalla said the parties had 30 days to remedy the situation or face sanctions that including fines or ultimately the withdrawal of the local licence.
"This is a clear violation of the law in our country," Moungalla said, adding that the government "had within its legal arsenal the right to be informed and to give its agreement in principle" to such deals.
A Bharti Airtel spokesman in New Delhi declined comment when contacted by Reuters, as did Zain's Congo unit.
Congo is at least the second country to object to the deal after Gabon voiced similar complaints on March 29 -- something which did not stop the accord being signed two days later.
Bharti is currently in the process of getting regulatory approval for the accord.
Zain is the dominant mobile operator in Congo with an estimated 1.5 million subscribers, Congolese officials said.
Fines could run to one percentage point of local turnover with other sanctions being a reduction in the duration of the operating licence, a suspension or outright withdrawal of the licence.