Weeks of protests toppled the regime of Hosni Mubarak, the former president [AP]

Egypt's stock market has plummeted almost nine per cent in its first day of trading in nearly two months, with foreign investors leading a sell-off over concerns about the country's stability after mass protests toppled the regime of Hosni Mubarak, the former president.

Earlier, officials suspended trading for half an hour after shares plummeted by about 10 per cent within a minute of the exchange reopening on Wednesday.

Al Jazeera's Sherine Tadros, reporting from the capital Cairo, said the intitial 10 per cent drop translated into about $6.8bn being lost.

"The exchange was suspended to prevent any more panicked selling," she said.

Egypt's exchange had been closed since January 27 after demonstrations paralysed the Arab world's most populous nation.

It had been widely expected to fall on Wednesday, with investors concerned by economic turmoil wrought by the uprising, including labour unrest.

Many investors decided to withdraw their money from the market on Wednesday amid ongoing investigations of former regime officials and some of the country's top businessmen whose companies are listed on the exchange.

Shares for Telecom Egypt, Commercial International Bank, and Orascom Construction Industries all fell 10 per cent on the initial reopening. 

In efforts to stabilise the index, authorities have announced that for the first week the market will only function three hours a day, instead of four.

The reopening comes just days after Egyptians voted overwhelmingly in favour of constitutional amendments, paving the way for elections within six months.

Source: Al Jazeera and agencies