Troubled Brazilian operator Oi played down speculation it is close to a deal to sell its stake in Angolan operator Unitel, despite reiterating it does plan to offload the business in future.

Reports stated the operator had received bids from two parties, both of which already own 25 per cent of Unitel, meaning the Oi stake would take their total to 50 per cent.

One offer, from businesswoman Isabel dos Santos, consists of $850 million in instalments, with a potential cash payment of a defined amount adjusted to a present value.

Dos Santos is Africa’s richest woman: she holds significant investments in Portugal and Angola, and is active in the telecoms sector.

The second reported bid, from state-owned oil company Sonangol Group, comprises a $1 billion cash payment.

In its clarification to the markets, Oi said it had not received a proposal from the oil company and there is “no finalised negotiation”.

It is no secret Oi is looking to dispose of the Unitel stake as it looks to turnaround its operation in Brazil. It gained the business through an earlier tie-up with Portgual Telecom, which ended when the European business was acquired by Altice.

Bloomberg previously reported dos Santos secured backing for her board role at Unitel despite a dispute with Oi over dividends due from the Angolan company. Sonangol Group was said to have seen the need for change to ensure a single shareholder does not exert a controlling influence.

The remaining Unitel stake is owned by a company of Leopoldino do Nascimento, the former head of the Angolan President’s security service.