Tata Teleservices on Thursday launched Push-to-Talk services offering customers the facility to make unlimited calls without any long distance or roaming charges within the network on a monthly rental of Rs 99.

The PTT service, which is the first by any mobile operator in the country, will offer instant connectivity across the country and Internet surfing at 3G speeds.

Announcing the launch of the service, Amit Bose, president, Tata Teleservices, said it was targeted at corporates, SMEs and individuals, and will be available on a Kyocera handset costing Rs 5,000 with Qualcomm's BREW Chat applications.

Presently, upto four subscribers sitting anywhere in the country can talk to each other at a cost of Rs 99 each.

The company has announced a CDMA based PTT service for post-paid users who will be paying Rs 99 a month for unlimited calls and will either buy a handset for Rs 5,000 upfront or pay Rs 1,000 with 12 installments of Rs 350 each.

The company will soon launch its pre-paid version, Bose said, adding PTT will have international roaming within a year.

The company also announced a GSM based PTT services with a handset price of Rs 15,000.

It offers CDMA-based mobile service under the brand name 'Tata Indicom' and is eyeing a customer base of 50,000 in the first year from the National Capital Territory.