London's FTSE 100 index of top shares slid 0.34 percent to 6,070.31 points near the half-way mark, Frankfurt's DAX 30 eased 0.01 percent to 7,322.73 points and the Paris CAC 40 dipped 0.12 percent to 4,103.32 points.
In foreign exchange deals, the euro firmed to 1.3643 dollars, compared with 1.3621 dollars late in New York on Tuesday.
The British stock market was pulled lower as a number of top companies went ex-dividend, meaning that their shares no longer carry the right to their most recently declared dividend.
"The FTSE is feeling some early pressure as a cluster of companies go ex-dividend today," noted IG Index sales trader Ben Critchley.
"The likes of GlaxoSmithKline, BP, Shell and Unilever all dropped after losing their payout attractions."
However, on London's second-tier FTSE 250 stock market, the London Stock Exchange saw its share price rocket more than nine percent after it announced a huge merger deal with its Canadian counterpart.
LSE shares soared 9.3 percent to 975 pence on the FTSE 250 index, which was 0.65 percent lower in value.
"London Stock Exchange Group plc and TMX Group Inc. today announced an agreement to combine Europe's and Canada's leading diversified exchange groups in an all-share merger of equals," the pair said in a joint statement.
"The merger will create a world-leading organisation and is unanimously being recommended by the boards of both LSE and TMX."
The transaction was billed as a merger of equals, but LSE investors will hold the upper hand with 55 percent of the new group, while TMX shareholders will have 45 percent. Both exchanges retain their existing brand names.
The company, which will span 20 trading markets and platforms across Europe and North America, will be one of the world's biggest trading platforms and will dominate raw materials and energy.
The LSE Group's chief executive, Frenchman Xavier Rolet, will take up the same role at the new group, while TMX boss Thomas Kloet will become president.
Later on Wednesday, meanwhile, traders will turn their attention to crucial testimony from US Federal Reserve Chairman Ben Bernanke.
"It is a fairly light economic data calendar today so all eyes will be on Bernanke's testimony to the House Budget Committee at 1500 GMT," said analyst Kathleen Brooks at trading site Forex.com.
"He is expected to stick closely to the same script he used at a speech last week to the National Press Association in Washington, where he reiterated his commitment to the second round of quantitative easing and acknowledged the pick-up in economic data while the labour market remains sluggish."
Asian markets mostly fell Wednesday after China hiked interest rates for the third time in four months, causing nervousness around the region.
Shanghai fell 0.89 percent, led lower by property developers, while Hong Kong tumbled 1.36 percent.
Tokyo's Nikkei index ended the session down 0.17 percent, as weakness among stocks with exposure to China offset optimism caused by a weaker yen, which helps Japanese exporters.
The People's Bank of China said Tuesday it was raising the one-year deposit and lending rates by 25 basis points each, taking them to 3.0 percent and 6.06 percent respectively, as it seeks to tame soaring inflation.