(Adds further quotes from Silva, background)
By Sergio Goncalves
LISBON, Dec 4 (Reuters) - Isabel dos Santos, the daughter of Angola's president, wants to become a major shareholder in Brazil's Oi to develop a leading telecoms business across the Portuguese-speaking world, Mario Silva, a director of her Terra Peregrin firm said on Thursday.
Dos Santos last month made an offer for Portugal Telecom SGPS, owner of a 25.6 percent stake in Oi following the Portugal Telecom merger which Oi is now effectively seeking to unwind.
Silva said Terra Peregrin's bid will not go ahead if Oi sells PT Portugal, the domestic Portuguese telecoms business which European rival Altice SA this week agreed to buy from Oi for 7.4 billion euros.
"We have had very positive and uplifting conversations with shareholders in PT SGPS," Silva said.
"Indeed, two and a half months ago the shareholders that met at a shareholder assembly ratified the idea of advancing with the merger (with Oi), not the sale of PT Portugal."
However, some analysts have questioned the likelihood of dos Santos's bid succeeding at the offer price of 1.35 euros, which Silva said will remain unchanged.
Silva added that dos Santos would not have progressed with her bid, "without talking with some of the biggest stakeholders in Oi", but would not elaborate further.
Shares in Lisbon-listed PT SGPS were trading at a premium to the Peregin offer on Thursday, at 1.4120 euros.
In bidding for PT SGPS dos Santos wants to link the Portugal Telecom business, Oi and Angolan telecoms firm Unitel, Silva said.
"Terra Peregrin wants to be a minority shareholder, without control, but with a relevant stake of a group in Brazil which has holdings in other (geographic) areas," Silva told reporters in the first official comment on dos Santos's bid rationale.
"We want to return to the corporate project of this leader in the Portuguese-speaking world, involving 260 million people and more than 110 million clients."
Dos Santos, who is listed by Forbes as Africa's richest woman with a net worth of $3.7 billion, already has a large stake in Portugal's second-biggest telecoms firm, NOS.
Dos Santos is chief executive of Unitel and owns 25 percent of the company, with other Angolan investors, including state-oil company Sonangol, holding another 50 percent.
The remaining 25 percent is owned by Africatel, the majority-owned regional subsidiary of Portugal Telecom which now belongs to Oi. In September Oi said it was looking to sell its 75 percent stake in Africatel Holdings.
Following the Oi merger, PT SGPS's stake in Oi is effectively its only asset, apart from 900 million euros of debts owed by Rioforte, a now bankrupt investment vehicle of the Espirito Santo family.
The default on that debt earlier this year led to a revision of the terms of the Oi merger with Portugal Telecom, handing the debt back to Portugal Telecom SGPS and reducing its stake in Oi to 25.6 percent from 38 percent. (Writing by Axel Bugge; Editing by Greg Mahlich)