Airtel Africa, a subsidiary of Indian telecoms group Bharti Airtel, is considering a stock market flotation in London, it said on Tuesday, part of efforts to expand its data and mobile money services across Africa. The company is aiming to raise around $1-billion in a June equity offering, a source close to the deal said. Airtel operates in 14 African markets including Democratic Republic of the Congo, Kenya, Nigeria, Rwanda, Seychelles, Uganda and Zambia.