Bharti Airtel promoted DTH business head Sunil Taldar to the level of director (market operations) to oversee Airtel's operations nationally and is likely to redesignate him COO soon. The move comes with COO Ajai Puri set to retire at the end of December after a17-year stint. The top-level leadership role change was announced in an internal company memo from Airtel chief executive Gopal Vittal, a copy of which was seen by ET.