Shares in Brazil's second-largest wireless phone company jumped 6.7 percent. Telecom Italia holds a 67 percent stake in the company. The deal would aim to raise at least $12 billion, according to the reports.
Despite ongoing concerns over negotiations surrounding the US debt ceiling, Latin American stocks were initially boosted by news that US President Barack Obama will nominate Janet Yellen to run the Federal Reserve.
The US Treasury is expected to exhaust its borrowing capacity by Oct. 17, when it will have only about $30 billion left in cash to honor its obligations.
While many investors expect US lawmakers to reach a last-minute agreement to lift the country's debt ceiling, others preferred to be on the sidelines while the US political scenario remains unclear.
Concerns about an eventual tapering of the Fed's stimulus program, coupled with weak economic growth in Brazil, are expected to drive the Bovespa index to close 2013 at its lowest level since the 2008 financial crisis, a Reuters poll showed on Wednesday.
Mexico's IPC stock index was down 0.13 percent, led lower by a 1.15 percent decline in shares of broadcaster Televisa , while Chile's IPSA index fell 0.87 percent thanks to a 1.78 percent decline in shares of energy company Empresas Copec.