* Net profit 4.11 bln rupees vs 3.46 bln rupees estimate
* Revenue grows 4 pct in line with estimates
* Tower operators bet on mobile data growth to boost demand
NEW DELHI, Jan 23 (Reuters) - Indian telecommunications tower operator Bharti Infratel Ltd beat estimates with a surge in quarterly net profit, helped by higher investment income and lower interest expenses.
Bharti Infratel, just under 80 percent owned by top Indian phone carrier Bharti Airtel Ltd, said on Thursday consolidated net profit rose 62 percent to 4.11 billion rupees ($66.5 million) for the third quarter to end-December, from 2.54 billion rupees a year earlier.
Revenue for the December quarter grew an annual 4 percent to 27.31 billion rupees.
Five analysts on average had expected the company to report a net profit of 3.46 billion rupees, while the average revenue estimate of seven analysts was 27.48 billion rupees, according to data compiled by Thomson Reuters StarMine.
Tower operators, who get their revenue from leasing mobile phone masts to cellular carriers, are betting on growth in mobile data networks to boost demand for mobile phone masts. The industry lost some clients last year after a court order forced several carriers to shut down or scale back.
Bharti Infratel, which raised about $512 million in 2012 from an initial public offering, is also expected to benefit from a recent network sharing agreement between parent Bharti Airtel and conglomerate Reliance Industries.
Bharti Infratel expects carriers to expand 3G networks in coming quarters as they see growth in revenue from data, Managing Director Akhil Gupta said in a statement.
The company, which is yet to spend much of the money raised from the IPO and has invested it in mutual funds, said other income rose 45 percent to 917 million rupees. Finance costs were down by a fifth.
Shares in Bharti Infratel, valued at about $5 billion, were up about 1 percent by 0653 GMT, having risen as much as 3.7 percent after the results. BNP Paribas last week downgraded Bharti Infratel citing limited upside potential. ($1 = 61.8450 Indian rupees) (Reporting by Devidutta Tripathy; Editing by Jeremy Laurence)