In a move that could trigger another tariff war among mobile operators, Anil Ambani-led Reliance Communication launched GSM services in Mumbai and offered free talk-time worth Rs 900 spread over three months.

"New subscribers would get Rs 10 talk-time every day for the first 90 days and has offered tariffs of Re one a minute for local calls and STD would cost Rs 1.50 per minute on any network," Dinesh Gulati, head of Western region, said.

After consuming Rs 10 during the day, the subscribers can use top up cards with denominations ranging between Rs 10 to Rs 500 with the same tariffs.

When contacted Ambani told PTI, "In 2003, Reliance changed the face of the telecom sector in India. Through our nationwide GSM launch coupled with company's continued focus on our number one CDMA Network, we will once again endeavour to re-write the rules of the industry by offering an unbeatable coverage, quality services and above all the value for their money."

Over and above the free-talk time, the Reliance GSM customers will get unlimited calling on Reliance network (both GSM and CDMA) absolutely free between 10 PM to 6 AM through out Mumbai, Maharashtra and Goa, giving access to seven million Reliance phones in the region.

The new GSM SIM cards would be available for Rs 25 with a validity of six months, Gulati said, adding the initial plan has been designed keeping in mind the subscribers in sub-Rs 300 mobile expenses.

He said the company was working out various other pre-paid tariff plans and would announce during the next three months.