Shares on the leading ATX index of the Vienna Stock Exchange fell by 10.91 per cent Friday afternoon after the market had been suspended until midday due to high volatility.

Vienna Stock Exchange spokeswoman Beatrix Exinger said the bourse had also needed time to implement new trading rules in response to the expected market fluctuations.

According to these new guidelines by Austria's financial oversight authority, trading of a company's share can be stopped if its price moves by more than 10 per cent.

For eight out of the 20 companies on the ATX, trading was suspended on Friday afternoon.

The Vienna Insurance Group was among the affected shares, as it had lost 18.17 per cent until its trading was halted.

As in the past days, Erste Group Bank AG and Raiffeisen International Bank-Holding AG also suffered heavy losses as their shares plummeted by 13.88 per cent and 21.72 per cent respectively until around 15:30 CET.

Another factor for closing the market were the heavy losses over the past days, Exinger said.

This week, shares on the blue-chip ATX index have lost 23 per cent of their value by Thursday evening.

As falling banking stocks account for around a quarter of the market capitalization on the small bourse, the Vienna Stock Exchange has underperformed other European exchanges this week.

Since the ATX was one of the smaller European indexes in terms of capitalization, Raiffeisen analyst Johannes Mattner explained, investors withdrawing from the market had a bigger effect than in bigger bourses.

"If someone backs out, these markets lose ground fast," he said.

Another factor for the bad performance of companies listed in Vienna was their exposure to Central and Eastern European business, analysts said.

Bauernfried said that previously, Vienna had outperformed other markets because of this factor, but now it had become "a big liability for some companies," such as the building group Strabag SE, whose trading was also suspended.

The Bucharest Stock Exchange also halted regular trading Friday for the second time this week, while stock exchange authorities in Moscow announced that they were delaying the opening of trading.

Since its record hight in July of last year, shares traded in Vienna have lost 61.5 per cent of their value and stood at a total of 64.5 billion euros (88.2 billion dollars) as of Thursday evening.