Almost 80 per cent of telemarketing firms continue to pester thousands of subscribers in blatant violation of telecom regulations.

An Indian telemarketing company makes 20 to 25 calls per 'seat' (operator) and most of these companies have a minimum of 20 to 25 employees who work in shifts.

Even conservative estimates would peg the figure at around 30 million calls per day by all telemarketers across the country. Telemarketers sell services for everything from mobile phones to credit cards and bank accounts.

Effective October 12 this year, it has become mandatory for telemarketing companies in India to register with the recently-launched National Do Not Call registry.

The Telecom Regulatory Authority of India has authorised service providers to either penalise errant telemarketers with a fine of Rs 500 per unsolicited call or disconnect their lines following subscriber complaints.

However, with the regulator not fixing a deadline for registering with the NDNC, the menace is expected to continue for a while.

"Of the 55,000 to 60,000 telemarketing companies in the country, only 10,700 have registered with the NDNC. This is alarming. Only listed companies are allowed to operate while the remaining continue to make unsolicited calls to telecom subscribers," an official with the department of telecommunications confirmed.

Applications of 3,000 companies are under process and, as on November 27, the regulator had rejected 7,100 applications after preliminary verification. The unregistered companies, and those rejected, are still doing business, added the official.

A Trai official confirmed that unsolicited calls were being made by telemarketers and that it was receiving complaints from customers.

The regulator is also considering making norms stricter for telemarketing companies, while it would also double the current fine per unsolicited call to Rs 1,000.