By Catarina Demony and Victoria Waldersee
LISBON (Reuters) - Angola may ask Portuguese authorities to seize assets belonging to Isabel dos Santos, billionaire daughter of a former Angolan president, who is a suspect in a fraud investigation, Angola's attorney general said on Friday.
Angola named dos Santos a formal suspect over allegations of mismanagement and misappropriation of funds during her time as chairwoman of state oil company Sonangol, while Portugal's market watchdog has opened inquiries into various firms in which she holds stakes.
Dos Santos, eldest child of former president Jose Eduardo dos Santos, has denied any wrongdoing.
In a statement to Reuters on Thursday she said she "always operated within the law and all my commercial transactions have been approved by lawyers, banks, auditors and regulators".
The attorney generals of Portugal and Angola, Lucilia Gago and Helder Pitta Groz, met in Lisbon on Thursday to discuss, among other things, how both countries could collaborate on the dos Santos' case, Pitta Groz told Portuguese broadcaster RTP during a television interview.
Asked by RTP if Angola could ask Portugal to seize dos Santos' assets, namely her shares in Portuguese companies and Portuguese bank accounts, Pitta Groz said: "It could happen ... It could happen."
"I will not say this is a reality now ... but when teams start working they could reach that conclusion," he said.
Separately, in an interview with Portuguese TV channel SIC, Pitta Groz highlighted that the civil case against dos Santos could be closed if she and her associates paid the state the $1.1 billion it alleges she and her associates owe for alleged embezzlement of public funds.
The second, separate case against her and three Portuguese nationals is a criminal case related to alleged mismanagement of Sonangol, which would remain open regardless of whether the debt was paid.
Pitta Groz told SIC dos Santos and other suspects, regardless of their nationality, should face justice in Angola.
One of the companies where dos Santos held shares, Efacec, said on Friday that dos Santos would offload her controlling stake in the firm - her second such move this week.
Efacec said in a statement that dos Santos had told the board she had decided to withdraw from the company's shareholding structure. It did not specify a reason and made no mention of any accusations against her.
On Wednesday, small Portuguese lender Eurobic, in which dos Santos was the largest shareholder with a 42.5% stake, said the businesswoman had decided to sell her share.
Dos Santos bought her controlling stake in Efacec for around 200 million euros in 2015 through offshore company Winterfell Industries.
The decisions to withdraw from Efacec and Eurobic coincided with increased scrutiny of dos Santos after hundreds of thousands of files - dubbed the "Luanda Leaks" - were released by several news organizations on Sunday.
A spokeswoman for the European Banking Authority (EBA) told Reuters on Friday the regulator was "aware" and "following developments" in the dos Santos case and, without providing any further details, said they were in touch with competent entities.
Dos Santos still holds significant indirect stakes in several important Portuguese firms such as oil firm Galp Energia and telecoms company NOS.
Dos Santos and Portuguese retailer Sonae each own 50% of holding company ZOPT-SGPS, which controls 52.15% of NOS.
Following the scandal, three non-executive board members at NOS stepped down from their roles on Thursday, the company said in a statement.
NOS shares fell by more than 5% on Friday morning before recovering most of the losses to trade 0.5% lower.
(Reporting by Sergio Goncalves, Andrei Khalip, Catarina Demony and Victoria Waldersee; Editing by Kirsten Donovan and Grant McCool)