Stock markets across the Nordic region plunged by closing Monday, with the Oslo bourse falling nearly six percent, amid fears of a new sharp global downturn.

The Nordic region markets briefly flirted with the positive territory shortly after opening Monday amid short-lived euphoria over the European Central Bank's pledge to prop up eurozone bond markets.

But by midday, fears linked to the US and eurozone debt crises had clearly taken over and by closing time the Nordic markets concluded their 11th straight day in the red.

The Oslo stock exchange was down 5.65 percent Monday, and has thereby lost 21.68 percent of its value since the beginning of the year.

The Stockholm OMX30 index did not fare much better, dropping 4.82 percent by closing, entailing a drop of 21.94 percent since January, while the Helsinki bourse fell 4.2 percent Monday, landing 31.87 percent lower than at the beginning of 2011.

The Copenhagen stock exchange fell 3.15 percent Monday, and has dropped 20.63 percent since the beginning of the year.