(Telecompaper) Singtel has announced plans to invest up to INR 26.5 billion (USD 413 million) in shares in Indian operator Bharti Telecom, and thus slightly increase its stake in the holding company for Indian operator Bharti Airtel to just under half. The purchase, subject to approval by Bharti shareholders, could increase Singtel's stake in Bharti Telecom by up to 1.7 percent to 48.9 percent and its holding in Bharti Airtel by up to 0.9 percent to 39.5 percent.