The ATX index fell by almost 62 points -- or 3.0 percent -- to 1.984,15 points, the first time it has fallen beneath the 2,000-point mark since July 2009.

Speculation over a potential default on Greek debt held back investors, according to the Vienna stock exchange.

The biggest losses in early morning trading were shown by Raiffeisen Bank International, which was down 7.35 percent at 22.70 euros ($30.80), followed by Erste Group, down 5.65 percent at 20.38 euros.