New Delhi, Mar 11 (UNI) Following a TRAI directive, all mobile operators in the country will now offer 'Do Not Call' registry to their subscribers to prevent them from attending unsolicited promotional calls and messages.

To avail the service, the subscribers can register their mobile numbers online and also by sending SMSs to their customer care centres. The Do Not Call or Do Not Disturb registry will contain a list of mobile numbers to which the mobile operators wil not make any promontional call or messages.

The service is available with all mobile service providers, except Bharat Sanchar Nigam Ltd (BSNL), ''which is in the process of implementation,'' a Telecom Regulatory Authority of India (TRAI) advertisement said.

The telecom regulator has advised the service providers to provide a special ring back tone to the calling party when a person is on roaming. The calling party will be informed regarding the international roaming status of the called party through a special tone.

''Mobile users can activate this facility before going abroad.

This will enable minimising calls when on international roaming, if the calling party excercises restraint,'' the TRAI said.

This facility is not available with BSNL, Reliance and Tata Indicom.

The authority also said it had already initiated consultation process to curb unsolicited commercial communication from telemarketers.

UNI