* Wireless carrier books 317 million reais Q3 net income
* Misses market view of a 334 million reais qrtly net
* 1.15 billion reais EBITDA up 11 pct from year ago
SAO PAULO, Oct 31 (Reuters) - TIM Participacoes, Brazil’s second-largest wireless phone company, posted a 116 percent jump in third-quarter profit from a year ago as a growing customer base boosted revenue.
The Sao Paulo-based company known as TIM Brasil, which is run by Telecom Italia , said in a securities filing on Monday that its net income rose to 316.6 million reais ($186 million) in the quarter.
Analysts were expecting net income of 334 million reais, according to the average forecast of a Reuters poll.
TIM’s growing share of Brazil’s booming wireless market helped boost net revenues 19 percent from a year earlier. The company’s client base grew 26 percent from the same quarter a year ago to 59.2 million users.
But growing competition pressured profit margins as carriers fought for free-spending customers in the current strong job market. Earnings before interest, taxes, depreciation and amortization, a gauge of operating profit known as EBITDA, rose 11 percent to 1.15 billion reais from a year earlier.
However, that sum as a share of revenue -- a ratio known as the EBITDA margin -- slipped nearly 1 percentage point from a year earlier to 11.7 percent in the quarter.
TIM shares closed 1.3 percent lower at 8.88 reais each on Monday. The stock has gained more than 35 percent this year, while the Bovespa stock index lost over 15 percent.
$1 = 1.69 reais Reporting by Reese Ewing; Writing by Brad Haynes; Editing by Muralikumar Anantharaman