UPDATE 1-TIM Brasil sees client base up 28 pct, higher capex this year

* Capital expenditures seen rising from 3.4 bln reais

* Coverage seen growing by 2015; client base seen up

SAO PAULO Feb 6 (Reuters) - Tim Participações SA will likely invest this year more than the 3.4 billion reais ($1.7 billion) it spent in expansion and network upgrading in 2012, as Brazil's No. 2 wireless carrier faces increased government oversight of the industry.

TIM Brasil, as the Brazil-based mobile telephony unit of Telecom Italia SpA is known, expects to have 90 million mobile phone lines active at the end of this year, up 28 percent from 2012, according to information filed with Brazil's securities regulator on Wednesday. The company ended last year with 70.2 million lines in operation, the company said.

Coverage of third-generation mobile telephony, known as 3G, will rise to 80 percent of Brazil's population by 2015, compared with 72 percent at the end of last year, the company said.