Bharti Airtel International's (Airtel) subsidiaries in Burkina Faso, Chad, Congo Brazzaville and Sierra Leone are the subject of a possible acquisition by Orange.

The two telecommunications operators are said to have entered into negotiations.

A press statement issued by Orange, which operates in 29 countries worldwide with a total customer base of 247 million customers as at 31 March 2015, confirmed news of the agreement.

Airtel has not given reasons for its wish to sell off the four subsidiaries.

In a message on Twitter Orange chief executive officer Stéphane Richard (@srichard) said he is "thrilled to explore acquisition of 4 Airtel subsidiaries" in a tweet soon after the press release was issued.

Richard added that Africa & Middle East is strategic for Orange and has a strong potential for growth in the same tweet.