By Benjamin Horney (October 31, 2014, 5:01 PM EDT) -- Brazilian telecom powerhouse Oi SA is teaming up with Mexico's America Movil SAB and Spain's Telefonica SA to offer to buy Telecom Italia SpA's Brazilian mobile phone unit TIM Participacoes SA for about $13 billion, Reuters reported on Friday. According to the report, the companies plan to present their bid within the next couple of weeks. The news comes about a month after reports surfaced claiming that Oi SA was hoping to raise money to make a bid of as much as $12.8 billion for TIM Participacoes. Meanwhile, earlier this month, it was reported that Telecom Italia was nearing a deal to sell the mobile phone towers operated by TIM Participacoes, not the whole company, for up to $1.1 billion....