Operators in the hyper-competitive telecom sector have been selling or paring stake in their non-core assets. While Vodafone India and Idea Cellular are selling stand-alone towers to ATC, Bharti Airtel said it was considering a sale of controlling stake in its tower arm Bharti Infratel Ltd. Bharti Airtel and its wholly-owned arms own 53.51% in Bharti Infratel at present.