Updated

Shares on the Athens Stock Exchange plunged Monday to their lowest level in more than 14 years, with the bourse's general index sinking below the 1,000-point mark as financial markets remained spooked by a downgrade of U.S. debt.

The Greek index dropped 6 percent to 998.24 points -- the lowest level since January, 1997.

That's markedly more than the declines recorded in other markets in Europe.

Debt-ridden Greece became the first European Union country to seek an international bailout last year, when it saw its borrowing costs spiral out of control as investors doubted the country could repay its massive debts.

The financial crisis has also affected other eurozone countries, with Portugal and Ireland also receiving bailouts.

On Monday, Europe's central bank is widely thought to have begun buying the depressed-bonds of Italy and Spain to calm investor fears that the two countries won't be able to pay their debts.

Though that bond-buying effort appears to have worked in the short-term by reducing the two countries borrowing costs, stock markets around the world have been in retreat as investors respond to Standard & Poor's momentous downgrade of the U.S.'s rating.