New Delhi, May 15 : The total number of GSM subscribers in April 2013 stood at 664.45 million, up by 3.51 million, according to data released by Cellular Operators Association of India (COAI) Wednesday.

Bharti Airtel clinched the top position with 188.80 million subscribers after adding 601,252 new customers in April, followed by Vodafone India with 153.78 million subscribers up by 1.42 million. Idea Cellular gained 1.28 million new customers in April.

The MTNL lost 100,127 GSM customers ending April with 4.72 million subscribers. Loop Mobile's customer base remained flat at 3.03 million. The BSNL's customer base was stable at 97.17 million. (IANS)