While the first four companies have already joined the new unit as stakeholders, Tata Net, the V-sat solutions arm of the Tata group, is expected to join the ranks in a couple of weeks.

"We were assigned about 400 corporate clients of our constituent companies to look after sales and marketing and delivery of integrated communication services. This number is likely to increase further over a period of time," Ajay Pandey, president of the new group told media persons today.

A key role for TEBU would be to target enterprises with sizeable telecom spends and offer them customised end-to-end voice and data solutions through a single interface.

Pandey was here to make a formal announcement about TEBU operations kicking off at eight locations - Mumbai, Delhi, Kolkata, Chennai, Hyderabad, Bangalore, Pune and Ahmedabad from Friday.

The Indian telecom market size is estimated at Rs 34,250 crore with wireline enterprise voice market contributing about 50 per cent, wireline consumer voice spend contributing 34 per cent to the total business.

Wireline data services used by enterprises and wireless services to retail consumers contribute 7 per cent each to the total business while wireline data for enterprises and consumers contribute the rest, Pandey said.