(Telecompaper) Bharti Airtel, which operates in 20 countries across Asia and Africa, announced that it has crossed the 300 million customers mark across its operations. The milestone includes customers across mobile, fixed line and DSL, and DTH services. The operator reached 100 million customers in 2009 and crossed the 200-million mark in 2012. The latest 100 million customers have joined the Airtel family in less than two years. The company ranks as the fourth largest mobile service provider globally and second-largest globally outside of China. Airtel's mobile networks cover over 1.85 billion people across 20 countries and carry over 311 billion minutes of calls every quarter.