London's benchmark FTSE 100 index fell 0.53 percent to 6,083.84 points in late morning deals. Frankfurt's DAX 30 dipped 0.10 percent to 7,493.61 points and in Paris the CAC 40 index eased 0.08 percent to 4,100.02.
The Stoxx 50 index of leading eurozone companies dropped 0.10 percent to 2,997.44 points.
Commodities giant Glencore set a price for its dual initial public offering in Hong Kong and London, which will be the world's biggest so far this year.
The Switzerland-based giant has priced its shares at between £4.80 and £5.80 ($7.91-$9.55) for a sale expected to raise about $10 billion.
The sale would value Glencore, the world's biggest commodities trader by revenue, worth about $61 billion.
In Frankfurt on Wednesday, Germany's Allianz became the latest insurance giant to see its profits hit by claims related to a string of natural disasters, most notably Japan's monster earthquake and tsunami.
Europe's biggest insurer said that first-quarter net profit slumped 44 percent to slightly more than 900 million euros ($1.3 billion) because of 750 million euros in expenses related to natural catastrophes. Its share price fell 1.03 percent to 105.30 euros.
Also in Frankfurt, BMW grew 0.46 percent to 63.66 euros after the German luxury car maker announced a four-fold increase in net profits for the first quarter and increased its sales forecast for the year.
BMW said it made a net profit of 1.2 billion euros in the first quarter, compared to 324 million euros over the same period in 2010, beating the average analyst forecast of 1.0 billion euros.
Consumers across Europe are meanwhile shying away from shops, with March data revealing a sharp drop in retail sales in the eurozone's biggest and most powerful economy, Germany.
Retail trade across the 17-nation eurozone fell by 1.0 percent in March compared to February, when it had risen slightly against January -- with a dramatic decline in pre-bailout Portugal also emerging from new data released by the EU on Wednesday.
Portugal raised 1.117 billion euros with the issue of short-term debt instrument on Wednesday, but the interest rate it had to pay rose, the day after a debt rescue deal with the EU and IMF.
Across the Atlantic, US stocks sagged Tuesday with little positive news on economic growth and lacklustre quarterly reports, especially from drugs giant Pfizer.
Before the markets opened, Pfizer, the world's biggest drug maker, reported first-quarter earnings jumped 10 percent, slightly above analyst estimates, but sales were lower from the year-earlier period and missed market expectations.
Pfizer shares closed down 2.8 percent at $20.44.