10. Tim Participacoes SA ( TSU) uses the global system for mobile communication to provide mobile telecommunications services throughout Brazil. The stock has gained 10% during the last one month. Developments: On Sept. 8, research firm Teleco reported that Tim is the fastest expanding 3G network company in Brazil. As of August 2010, the company had covered 155 cities with its 3G signal compared to 35 as of December 2009.