The Iseq followed other European markets lower today on worries about EU debt levels.
The Dublin market was down 9.39.84 points to 2974.04 at 2.18pm.
Elsewhere, European shares fell again, extending a sell-off into a third straight session, with heightened concerns over sovereign debt after Fitch Ratings said the UK faced a "formidable" challenge.
By 11.14am , the pan-European FTSEurofirst 300 index of top shares was down 0.9 per cent at 981.75 points.
Shares in Germany's utilities were lower, with RWE falling 3.6 per cent and E.ON down 3.7 per cent on the back of a government announcement to impose a tax on nuclear fuel.
Fitch said the UK may not be able to rely on spending cuts alone to cut its deficit over the medium term, which warrants a faster pace of medium-term reduction than set out in the previous government's budget.
Concerns over fiscal health in European countries and the impact of austerity plans on economic growth have been nagging financial markets, with the FTSEurofirst 300 down close to 12 perc ent since mid-April.
Adding pressure to the sector, European finance ministers sought agreement today on how to make banks pay for financial crises.
Across Europe, Britain's FTSE 100, Germany's DAX and France's CAC40 were down between 0.9 per cent and 1 per cent.
BP lost 3.8 per cent as US president Barack Obama stepped up his attack on the company following an oil spill in the Gulf of Mexico. BP shares are down more than a third from mid-April.
Within the sector, BG, Royal Dutch Shell, Total and ENI fell 1 per cent to 1.4 per cent, as crude prices hovered around $71 a barrel on concerns about the euro zone debt crisis and subdued optimism over US demand.
British supermarket group Tesco fell 3.2 per cent after Terry Leahy, chief executive for 14 years, said he was stepping down next year.
On the economic front, Germany's trade surplus widened slightly in April but analysts said a dip in exports was temporary and that foreign demand and the weak euro would continue to fuel growth in Europe's largest economy.
Earlier, markets had been encouraged by upbeat remarks from US Federal Reservechairman Ben Bernanke, who said European leaders are committed to ensuring the survival of the euro and have enough money to meet obligations of heavily indebted member countries.
He also said the US economy appeared to have enough momentum to avoid a "double-dip" recession, citing strengthening consumer and business spending.
Additional reporting: Agencies