The basic service subscriber base, which includes landlines, WLL (F) and digital mobile offered by private players, has declined 2.3 per cent in March from the previous month.
The latest figures from the Association of Unified Telecom Service Providers of India show private basic service providers recording a net addition of 367,486 subscribers in March.
They also had a combined subscriber base of 15.6 million, against 15.95 million in February.
The fall is owing to a 5.4 per cent drop in Reliance Infocomm's subscribers "deprovisioned" by the company during the month. The service provider had 10.6 million customers in March, against 11.2 million in the previous month.
"Reliance Infocomm had deprovisioned 984,123 connections because of issues like subscriber data verification and customer credit worthiness," said a company spokesperson.
Reliance added 377,743 new users to its base during the last month, to finish with a net deletion of 606,389 customers, AUSPI said.
Bharti finished the month with 856,560 subscribers, of which 21,055 were new additions.
HFCL Infotel Ltd ended with 246,696 subscribers including 6,442 new additions, Shyam Telelink with 184,736 and 13,352 additions and Tata Teleservices with 3.7 million and 200,000.
State-owned Mahanagar Telecom Nigam added 36,930 new subscribers during this period, while Bharat Sanchar Nigam is yet to release its figures for the period, AUSPI said.
