GSM operators added 7.12 million new subscribers in October, compared to 6.52 million additions in the previous month.
With this, the GSM subscriber base in the country stood at 625.41 million on October 31, 2011.
In October, Bharti Airtel, the largest GSM player, added 0.94 million users, taking its total subscriber base to 173.73 million, the data released by the Cellular Operators Association of India (COAI) showed.
The company had a 27.78% market share at the end of October.
Vodafone Essar, with a 23.33% market share, notched up 0.92 million new subscribers during the month. Its subscriber base reached 145.91 million in October.
Aditya Birla group firm Idea Cellular saw the highest number of additions during the month, with 1.63 million new users taking its total subscriber base to 101.81 million, while Aircel added 0.48 million customers to take its subscriber base to 60.28 million.
State-owned telecom firms BSNL and MTNL added 0.51 million and 34,919 new users, respectively, taking their subscriber base to 91.58 million and 5.36 million.
In addition, MTS added 0.79 million customers in the month of October 2011, taking its total customer base to 14.06 million.
The COAI data excludes data from Reliance Communications.
GSM (Global System for Mobile Communications) is the most popular standard for mobile telephony systems in the world.
The other technology platform on which Indian telcos offer services is CDMA (Code Division Multiple Access), where players such as Tata Teleservices (TTSL), RCom and MTS are the main operators. TTSL and RCom offer both GSM and CDMA services.