New Delhi, Apr 21 (IANS): India's GSM subscriber base grew by 1.04 percent in March with addition of 6.87 million mobile phone users, with Bharti Airtel alone signing up over 2.5 million customers, according to data released by Cellular Operators Association of India.

The total number of GSM subscribers in the country crossed 664 million as against 657.22 million in February.

Airtel currently has 181.28 million subscribers.

Idea Cellular followed Airtel by adding 2 million subscribers to have a total number of 112.72 million subscribers.

Uninor, whose all 22 licences stand cancelled following the Supreme Court's ruling earlier this month, added 1.3 million subscribers to take its subscribers count to 42.43 million subscribers.

Vodafone added 1 million users, thus taking its subscribers base to 150.46 million.

State-run telecom operators Bharat Sanchar Nigam Ltd (BSNL) added 8,92,900 subscribers, taking its total user base to 94.68 million and Mahanagar Telephone Nigam Ltd (MTNL) added 62,399 subscribers to have total of 5.59 million subscribers.