Bharti Airtel moved up one notch in global ranking to become the fourth largest mobile operator in the world in terms of subscribers. The revelations are contained in the Wireless Intelligence ‘Scoreboard’ operator ranking. It shows that by the end of the second quarter of this year, the company had over 250 million mobile subscribers across its operations, representing 13 per cent year-on-year growth.However, Bharti’s US$3.04 billion in mobile revenue in Q2 2012 is significantly lower than the four other operators in the top five, reflecting Bharti’s presence in the ultra low-cost, low-margin Indian and African markets.The new ‘Scoreboard’ tracks the top 20 global operator groups by connections based on majority owned assets in Q2 2012. Minority holdings (less than 50 per cent plus one share) are excludedAirtel launched its operations in Rwanda early this year.In June 2010, Bharti Airtel was ranked the fifth largest mobile operator in the world following its acquisition of Zain Group’s mobile operations across 15 African nations.