Mumbai: Tata Teleservices will spin off its cellular tower business into a separate unit in three months. The company has also earmarked Rs3,500 crore for expanding services in more towns across the country.

The company, which has invested Rs1,000 crore in the tower business so far, is in talks with six companies to operate its towers, Tata Teleservices CEO Darryl Green said. Tata Teleservices operates CDMA mobile services in India, the fastest-growing mobile phone market.

"Towers are passive infrastructure. We are actively discussing with various companies on having them take over the business," Darryl Green told reporters.

"We have a tremendous asset ... just about everyone you''ve heard of has been in talks with us," he said, but declined to name the companies or the valuation of the towers business.

Larger rival Reliance Communications and the country''s leading mobile services provider Bharti Airtel Ltd have also plans to hive off towers business into a separate units.

Reports have indicated American Tower Corporation, as also private equity firms, including Blackstone and Carlyle, and Singapore state investment firm Temasek Holdings, were interested in Reliance Communications'' towers unit.

Tata Teleservices, along with subsidiary Tata Teleservices (Maharashtra) Ltd., has more than 15.5 million subscribers in India.

The company would invest Rs3,500 crore in 2007-08 for rolling out services in more towns as it plans to add 100 million subscribers by 2011 from the present 15.5 million, Green said. Market leader Bharti Airtel and Vodafone, the newest entrant in the Indian mobile space, too have targeted addition of 100 million subscribers each.

India, the world''s fastest growing mobile market, is adding over seven million subscribers every month.