Mexican carrier Telmex became a major shareholder in Portugal Telecom Friday, acquiring a 3.4 per cent stake in the company. The move throws a spanner in the works of Portuguese conglomerate Sonae’s Eur10.7bn (£7.4bn) hostile bid for Portugal Telecom.

The stake was acquired via common stock and it is under stood the Telmex involvement was unsolicited. It is not clear whether Telmex intends to increase its stake in the future.

Portugal Telecom has been resisting Sonae’s takeover attempt since March, saying it “is of the opinion that the current and future value of Portugal Telecom is considerably higher than the offer price.”