As of April 3, the foundation had a 3.1 percent stake in the bank, having gradually sold a holding of 30 percent since mid-February to pay back debts.

The foundation has committed to keeping a 2.5 percent stake in the lender after a rights issue expected to be launched in May or June as part of an accord with two Latin American investors, Fintech Advisory and BTG Pactual Europe, that have bought part of its holding.

However, the bank has since said it is considering whether to raise the size of the capital increase, initially planned at 3 billion euros, and it is not clear whether this would have implications for the shareholder pact.

(Reporting by Stefano Bernabei, writing by Silvia Aloisi, editing by Valentina Za)