Fears over a political crisis in bailed-out Greece together with gloom over the outlook for the US deepened anxiety over the world economy as stock markets tumbled today.
The ISEQ index of Irish shares was down by 116.37 points to 4,381.39 - a 2.59% drop.
The FTSE 100 Index suffered its worst fall in 16 months as shares fell by 2.8%, or 181 points to 6211.6 with Germany's Dax and France's Cac 40 each dropping by a similar scale.
It added to losses in recent weeks which have seen the top-flight retreat from near record highs above 6900 at the start of September amid fears of the eurozone plunging back into recession.
Figures from the US today added to the anxiety, with retail sales for September down 0.3% on the previous month and other key data on manufacturing and business inventories cementing the gloomy picture, prompting steep falls on Wall Street.
Meanwhile, the main index on the Athens Stock Exchange was sharply lower while yields on Greece's 10-year bonds surged above 7% due to fears over the future of the country's bail-out plans.
It was prompted by growing support for the opposition anti bail-out Syriza party which has taken a lead in the polls amid a possible early election in February.
On currency markets it was a mixed day for sterling as America's weak economic data helped it climb by a cent against the greenback though it remained just below the 1.60 dollar level.