Henrique Granadeiro (pictured), the 70-year-old chief executive of Portugal Telecom (PT), has resigned just weeks after an awry debt deal forced the Portuguese incumbent to cut its stake in a merger with Brazil’s Oi.

PTs executive board, following Granadeiro’s departure, has been quick to distance itself from the doomed €897 million purchase of debt issued by Rioforte.

Rioforte, a holding company for the struggling Espirito Santo banking group – which is also a PT shareholder – defaulted on the debt repayments due in July.

In a statement the board said it had never approved or even discussed the deal. It has reportedly contacted auditors PWC to examine all investment made by PT in the Espirito Santo Group.

In a letter cited by the Portuguese media, and picked up by Reuters, Granadeiro said he was surprised by the default. He did not say he had personally approved the investment but was “sure the independent audit will show that I always acted in the interests of PT, its employees and its shareholders”.

He had been at the PT helm for barely more than one year.

Oi has complained too about being in the dark regarding Rioforte. Two Brazilian PT board members resigned last month complaining they only found out about the investment through a press release.

A PT shareholder meeting is scheduled for 8 September to discuss a way forward and all aspects of the Oi merger.