Portugal Telecom has acquired 25.3 percent of Brazilian operator Telemar Norte Leste (better known as Oi) for BRL8.32 billion (US$5 billion) – a larger stake than it had originally planned to buy, reports the Wall Street Journal The stake was built through direct investments in the company and indirect positions in its biggest shareholders, Portugal Telecom said in a statement. The Portuguese firm said in January that it planned to buy at least 22 percent of the Brazilian operator.