The rest is made up of minority stakes in several telecom operators including India's Bharti Airtel, Indonesia's Telkomsel and the Philippines' Globe Telecom. "The group would like to advise shareholders of Singtel and potential investors to exercise caution in their review of any media reports relating to Optus in the absence of any definitive announcements when dealing with the shares of the company," Singtel said in a statement. SingTel sells 0.8% stake in India's Bharti Airtel to GQG Partners for $711mn In November, Optus drew public ire after a 12-hour network blackout affected more than 10 million Australians.