Bharti Airtel added a maximum of 1.31 million GSM connections followed by Idea Cellular (1.17 million) and Vodafone India (1.13 million) in August this year, telecom group COAI said in a statement.
The GSM subscriber-base increased 0.62% to 4.49 million in August 2015 over previous month.
Maharashtra telecom circle added a maximum of 0.81 connections while Uttar Pradesh East remains the largest circle with a total of 64.28 million subscribers.
India's total GSM subscriber base rises to 726.10 million in August, COAI added.