Singtel on Friday confirmed it has sold 1.2 per cent stake in Bharti Airtel Ltd via a private placement to international and Indian institutional investors for two billion Singapore dollars ($1.54 billion as per exchange rate). The buyers included some of Bharti Airtel's existing shareholders. The stake sale was carried by Singtel as a part of its active capital management strategy to optimise asset portfolio and drive shareholder returns, the Singaporean telecom giant said in a press release.