After signing the 15-year deal, Tata Tele said: "This is a moment of pride for us, as we have become the first private telecom operator to enter into such a strategically important agreement with BSNL, one that will allow us to expand our telecom footprint across the country much more quickly."
TTSL, however, declined to give financial details of the deal.
"The agreement, which is valid for 15 years, will be applicable to both TTSL and TTSL (Maharashtra) Limited in all of India's 22 telecom circles," TTSL's Legal and regulatory affairs president Madhav Joshi said.
The deal comes at a very strategic time for Tatas as the company is in the process to launch its GSM mobile services under the Tata DoCoMo brand name and BSNL has infrastructure assets across the country -- the largest for any telecom firm.
In the last three months, the company has rolled out GSM services in nine circle -- Tamil Nadu, Kerala, Orissa, Karnataka, Andhra Pradesh, Mumbai, Maharashtra, Madhya Pradesh, Chhattisgarh and Haryana.