Telecom Regulatory Authority of India came down heavily on telemarketers on Tuesday by imposing a fine of Rs 500 on them for each unsolicited commercial call or message -- a move that would give relief to telephone users.

Issuing a new regulation to curb unsolicited commercial calls, Trai said the regulation would come into effect from Tuesday.

A national do not call registry containing list of telephone numbers of the subscribers who do not want to receive unsolicited commercial communication would be created by the National Informatics Centre within three months.

After the establishment of the NDNC registry, a telephone subscriber (landline or cellular) who does not wish to receive UCC can register his/her number with the telecom service provider for inclusion in the registry.

"The telemarketer will have to register with NDNC registry to avail the facility of scrubbing their calling list," Trai said in a statement.

An amount of Rs 500 per call/message has been prescribed to discourage telemarketers who makes calls to numbers registered in the do not call list.

"The defaulter telemarketer will face disconnection of telecom services," the regulator said.