The DFM index was 6.7 percent down just 10 minutes after opening at 0600 GMT, standing at 1,505.62 points, according to the market's website.

The market remained down 6.27 percent after more than one hour of trading.

The leading traded company, Emaar Properties, saw its share price plummeting by nearly 10 percent, the maximum allowed by the market regulations.

Emaar, which built the world's tallest tower, Burj Khalifa, in Dubai, has various projects in Egypt.

Air Arabia also saw its share plunge by nearly 10 percent. The Middle East's largest low-cost carrier has a hub in Egypt for its local joint venture Air Arabia Egypt.

A mass revolt broke out across Egypt on Tuesday against the decades-long autocratic rule of President Hosni Mubarak, with more than 100 killed in riots and demonstrations over the past five days and much of the country in turmoil.

Other Gulf stock markets were also down.

Neighbouring Abu Dhabi Securities Exchange was down 3.74 percent at 0645 GMT at 2,559.89 points.

Etisalat telecom company, which operates in Egypt through Etisalat Misr, was trading 3.35 percent down.

Kuwait Stock Exchange, the second-largest Arab stock market after Saudi Arabia's, was down 2.14 percent, or 148.4 points, to 6,795.6 points.

Qatar Exchange opened at 0700 GMT over five percent down.

The Saudi stock market plunged 6.43 percent on Saturday, its first day of trading. The market opens later in the day.

"Direct exposure to Egypt is an issue for some Saudi companies that have bought into Egyptian companies and established production facilities," said Jadwa Investment in a report Saturday.