GSM operators added 8.89 million subscribers in June, taking the total number of subscribers using the technology to 315.8 million.
In May, 8.3 million subscribers were added and the corrosponding figure for April was 8.9 million, the Cellular Operators Association of India said in a statement.
Bharti Airtel, added 2.82 million, increasing its subscriber base to 102.4 million. Vodafone-Essar, recorded a lower net addition of 2.37 million in June, compared to 2.54 million in May.
The Aditya Birla Group telecom service provider added 1.61 million subscribers during the month, up from 1.3 million added in May, while Aircel has added 1.11 million new users during the month.
The data did not include additions by Reliance Communications, as the company, which operates both CDMA and GSM service, does not provide separate GSM numbers.
