Bharti Airtel's pre-paid customers will have to pay more for making calls within the network in five states. For now, Bharti Airtel has raised tariffs in Delhi, Gujarat, Madhya Pradesh, Andhra Pradesh and Kerala that account for more than a quarter of its 176 million subscribers in India.
"Declining margins, high 3G and broadband auction prices, constrained spectrum and rural rollout aspirations leave us with little choice but to make price corrections," said a spokesperson.
Of the 840 million mobile subscribers in India, 98% or 823 million are pre-paid customers.
Airtel's rivals didn't comment on whether they planned a similar step, but industry sources said all telecom companies would raise pre-paid tariffs by about 20% in the next few months.
Effectively, this means a pre-paid customer, who has been paying Rs 500 a month, will soon have to pay Rs 600 a month.
The sources indicated the company would hike rates for all subscribers across the country depending on the customer response to Friday's rate hike.