LISBON, Nov 11 (Reuters) - Brazil's telecom company Oi toughened its stance on a bid by Angolan entrepreneur Isabel dos Santos for Portugal Telecom, saying on Tuesday the offer was "unacceptable" as it would alter the terms of a merger between Oi and PT.
It has previously said the 1.35 euro a share bid launched on Sunday was "untimely".
"Oi considers the tender offer unacceptable and confirms that it will not modify any corporate acts, definitive agreements or other instruments entered into in order to comply with the conditions stipulated in the offer," Oi said in a statement on Tuesday.
Dos Santos, the daughter of Angola's president, launched the bid for Portugal Telecom, a holding company which has no operating assets but owns a 25.7 percent stake in the combined Oi-PT company, in an attempt to thwart a 7 billion-euro bid for PT's operational assets by Altice. (Reporting By Andrei Khalip)