Lisbon - Shares in Portugal Telecom (PT) plunged almost 18 percent on the Lisbon stock exchange on Monday on uncertainty over prospects for a planned merger with Brazilian operator Oi.
PT was badly weakened, and the merger clouded, by the collapse of Portuguese bank Banco Espirito Santo in August.
Oi is now seeking to dispose of some assets in its partner company PT.
The proposed merger would create a giant operator in Portuguese-speaking countries.
The price of shares in PT, an important component of the main Lisbon index, sank 17.63 percent to 1.0 euro, the lowest level ever, in midday trading.
The overall Portuguese stock market was down 0.98 percent to 4,996.83 points. - Sapa-AFP