Tata Teleservices Maharashtra Thursday launched its GSM services under the Tata Docomo brand across the state.
The company has invested about Rs.1,000 crore in its GSM network.
It also launched a "pay-per-use" tariff, which enables customers to pay only for the seconds utilised, the company said in a regulatory statement.
An introductory offer of one paise per second for all calls across the country and international calling at per second billing has been launched.
Tata Teleservices Maharashtra is a subsidiary of Tata Teleservices, in which Japan's NTT DoCoMo has 26 percent stake, and which has received GSM spectrum for 18 out of the country's 22 telecom circles.
"Assam, the northeast, West Bengal and Delhi are the circles for which we are still awaiting spectrum," a Tata Teleservices spokesperson had earlier said.