Triggering a tariff war, Idea Cellular today slashed data charges by 90 per cent in eight circles, following Bharti Airtel and Vodafone, who recently cut their rates by similar margins in select circles.

"Idea Cellular...has revised data tariff in eight circles across the country...users can now access data for 2 paise/10 KB, which is a 90 per cent reduction in the existing tariff of 2 paise/KB," Idea Cellular said in a statement.

Bharti Airtel had yesterday slashed data usage charges by 90 per cent for pre-paid subscribers in Punjab and Haryana, a day after Vodafone lowered its data charges by 80 per cent for pre-paid and post-paid customers in three circles.

Airtel has reduced the price to 1 paisa per 10 KB from 10 paisa per 10 KB and Vodafone slashed the tariff from 10 paisa per 10 KB to 2 paisa per 10 KB.

Idea's new tariff is applicable to all 2G data users who use data on pay-as-you-go basis and also on an average on regular data from July 1, 2013 and the offer will be valid for 90 days, the statement added.

"The new data rate will be automatically implemented for all Idea 2G postpaid subscribers in these markets, effective July 1...prepaid users can avail the new rate with a value recharge priced between Rs 5-10," the statement said.

Idea said Tamil Nadu & Chennai, Karnataka, Kolkata, West Bengal, Assam, North East, Bihar, and Orissa circles will benefit from the revised data tariff.

"These eight circles comprise 1/3rd of the total mobile users in India, with a large number of users waiting to board the mobile broadband wagon. Availability of data at such affordable rates will usher in a new wave of mobile data growth in the country," Idea Cellular Deputy Managing Director Ambrish Jain said.