London's benchmark FTSE 100 index slid percent to stand at 6,703.99 points in afternoon trading.
Frankfurt's DAX 30 gained 0.43 per cent to 9,497.20 points and in Paris the CAC 40 added 0.26 per cent to 4,273.35.
The European single currency increased to USD 1.2541 from USD 1.2537 late in New York yesterday.
Switzerland's SMI index briefly rose above the 9,000 mark during the trading session, hitting its highest level since the end of 2007.
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The French government is reportedly considering injecting 2.0 billion euros into the company which is facing cash flow problems as interest in nuclear power has cooled since the March 2011 Fukushima catastrophe in Japan and its reactors under construction are hobbled by delays.
Royal Mail was the biggest faller on London's benchmark index after posting a drop in earnings as its parcels division faces fierce competition from US online giant Amazon, which is doing its own deliveries.
"We can expect more of the same from Royal Mail, while the expectation of hitting targets for the full year hinges on a good Christmas and thus the risk of disappointment is high," she added.
European stock markets were largely "taking a breather after two consecutive days of substantial gains," said Markus Huber, senior analyst at brokers Peregrine & Black.