India had a total of 509 million telephone subscribers at the end of September, of which 472 million were mobile subscribers, Telecom Regulatory Authority of India (TRAI) said.

Even as mobile subscriptions have been booming, with the country adding 15 million new subscribers in September, the number of fixed-line subscribers has been steadily falling.

In September, the number of fixed-line subscribers was down to 37.31 million from 37.33 million a month earlier, according to TRAI.

About 43.5 percent of India's population now have telephones, the authority said.

The rapid increase in the number of mobile phone connections in India has been helped by the introduction of GSM (Global System for Mobile Communications) service by the operators of CDMA (code-division multiple access) networks such as Reliance Communications or Tata Teleservices, a joint venture in which NTT DoCoMo has a 26 percent equity stake.

India's largest mobile services provider, Bharti Airtel, added 16.8 percent of the new subscribers in September. Tata accounted for 26.7 percent of the new additions in September, while Reliance and Vodafone accounted for another 13 percent each.

The market has also seen a fierce price war with many operators now offering tariffs starting at 0.01 Indian rupees per second (around US$0.013 per minute). Earlier tariffs were typically fixed for a minimum of one minute or multiples thereof.

Established players are trying to gain market share ahead of the entry into the market of newer players such as the Indian joint ventures of Telenor and Etisalat.

Deep price cuts and expansion into less lucrative rural markets have however resulted in slower revenue and profit growth for many operators. Last week, Bharti Airtel reported reduced revenue and profit growth in the quarter ended Sept. 30, as call durations and average revenue per user dropped, even though the number of subscribers increased.

Reliance Communications, India's second largest operator, also reported last week that its revenue had grown by 1 percent, but profits in the quarter ended Sept. 30 fell by 33 percent from a year ago. Both Bharti Airtel and Reliance said that the wireless sector in India is undergoing a challenging phase, with increased competition.