Tata Teleservices has become the fourth largest operator in terms of wireless subscribers with nearly 77 million users and has overtaken state owned BSNL.
TTSL is now behind only Bharti Airtel, Reliance Communications and Vodafone, the company said in a statement.
Tatas was the first company of introducing the concept of per second tariffs in mobile telephony that had forced all others to follow.
Both TTSL and TTSL (Maharashtra) offer dual technology (GSM and CDMA) mobile services across the nation.
After its collaboration with Japan's NTT DOCOMO in November 2008, TTSL has so far launched GSM services under the "TATA DOCOMO" brand in all the 18 telecom Circles where it received spectrum from the Government.
"We thank and appreciate every subscriber's ceaseless faith in us as a transparent, caring and competent telecom services company. Everyone in TTSL has complete satisfaction as we look back on the year gone by," Anil Sardana, Managing Director of Tata Teleservices Limited, said.
The introduction of many path-breaking, innovative and pioneering initiatives has been the reason behind this success, he added.
According to the latest figures released by telecom regulator TRAI, Bharti is the number one operator with over 139 million subscribers at the end of July this year, followed by RCom with over 113 million and Vodafone with over 111 million users.
BSNL has become fifth largest operator with 73.7 million wireless subscribers at the end of July this year.
TTSL had started offering CDMA mobile services in 2005 and got permission for dual technology (GSM also) only in late 2007 and got started getting GSM spectrum in January 2008.
The company has started GSM services in most of the circles it got spectrum but has failed to get GSM frequency in the most lucrative circle of Delhi despite several attempts.
TTSL claimed to have clocked a growth of 100 per cent in the year gone by as it had wireless subscriber base of 38 million in July 2009, the statement said.