According to O Globo, which mentions the sales contract, US $ 750 million will be transferred this Friday to the Brazilian operator, with Sonangol depositing the remaining amount within 90 days.
The deal caused Oi's shares to skyrocket, registering a 9.18 percent rise on the São Paulo Stock Exchange, with each company's security trading up to 1.07 reais.
On 9 January, Sonangol's communications and image director, Dionísio Rocha, had already confirmed the company's availability to acquire the Brazilian operator's 25 percent stake in Unitel.
"We are considering the possibility of holding PT Ventures [a company controlled by Oi], but everything depends on the decision of the Paris court", said the communication director, indicating, at the time, that the estimated value of the acquisition should be "the market".
The Paris Court of Commerce ordered Unitel's Angolan shareholders to pay Oi more than 600 million euros for violations of the shareholder agreement and proved that "transactions for their own benefit" were carried out.
Asked how the acquisition operation would be financed, Dionísio Rocha said only that "Sonangol is financing itself in international banking", without giving further clarifications.
Oi has been in the process of judicial reorganization since 2016 to reduce liabilities, which are around 65.4 billion reais.
The Brazilian company faces losses and has even hired financial advisors to evaluate the operation of mobile phones in the country.
In a report released earlier this week, financial analysts outlined a more positive scenario for the company, with the expectation of fundraising that would total about 8 billion reais.
According to the newspaper Valor Económico, this amount already included the perspective of the Angolan business, confirmed this Friday.
Last December, the operator was the target, under the Lava Jato operation, of an investigation into alleged irregular payments to companies linked to one of the children of former President of Brazil, Luiz Inácio Lula da Silva.
According to a statement sent by the Federal Public Ministry, the Oi group reportedly made suspicious payments of more than 132 million reais to companies controlled by Fábio Luís Lula da Silva, between the years 2004 and 2016.
Unitel, whose shareholder is the subsidiary of Oi PT Ventures, was involved in a global scandal, called ‘Luanda Leaks’, disclosed last Sunday by a consortium of investigative journalists.
According to the investigation, Unitel was the focus of deviations and illegal transactions.
Unitel had four shareholders, each holding 25 percent, PT Ventures (owned by Brazilian Oi), Sonangol, Vidatel (controlled by businesswoman Isabel dos Santos) and Geni (general Leopoldino Fragoso do Birth).