"The GSM subscribers increased by 4.41 million in September 2013, a 0.65 per cent increase from previous month," the report said adding the total number of GSM subscriber as of September 2013 stood at 678.82 million.
The growth in the GSM subscribers base was jointly led by Idea Cellular Ltd which added 12.07 lakh new customers in September, taking its total customer base to 12.72 crore, it said.
Vodafone closely followed Idea in terms of new subscribers addition by adding over 12.05 lakh new customers. The subscriber base of the company reached 15.55 crore in the reported month, the report added.
Telecom major Bharti Airtel added 11.6 lakh new customers during the month and maintained its leadership in the market with total mobile subscriber base of 19.33 crore customers.
Aircel and Uninor added 6.4 lakh and 1 lakh customers respectively, the report said.
New telecom operator Videocon continued to register highest growth rate in new subscriber addition. In September, the company's subscriber base grew by around 11 per cent to reach 32.4 lakh customers.
State run telecom company MTNL lost around 90 thousand mobile users during the month, as per the COAI data. There was no change in customer base of BSNL and Loop during the period, according to the report.
In terms of circle, UP East housed 5.93 crore customers, maximum in any circle, in September.