Bharti Airtel Ltd, which is in talks to buy a stake in Africa’s MTN Group Ltd, may have its debt ratings cut, depending on details of financing for the transaction, Fitch Ratings said on Friday.

Fitch has a BB+ rating on Bharti’s debt, its highest non- investment grade, and a ‘‘stable’‘ outlook for the company. Bharti and MTN, Africa’s biggest wireless-phone operator, said in separate statements on May 5 they were in ‘‘exploratory’‘ talks that might not lead to a transaction.