European stock markets dropped on Friday after rising most of the week in reaction to upbeat earnings and data, with traders taking profits amid lingering unease over the Russia-Ukraine crisis.
Wall Street also opened on the back foot, with investors worried about the crisis in Ukraine, and assessing varied US company results.
The euro maintained its momentum against the dollar after a pick-up on Thursday fuelled by a healthy consumer confidence reading from Germany.
Traders said sentiment on the foreign exchange market was that the European Central Bank would not ease monetary policy soon to counter any risk of deflation, and that they were waiting for a US monetary policy decision next week.
London's benchmark FTSE 100 index fell 0.22 percent to stand at 6,688.28 points in late morning trade.
Frankfurt's DAX 30 slid 0.82 percent to 9,470.31 points and in Paris the CAC 40 shed 0.26 percent to 4,467.72 compared with Thursday's closing levels.
European stock markets had closed on an upbeat note on Thursday as traders reacted to a string of earnings updates, data pointing to further easing of eurozone economic strains, and fresh takeover speculation.
In New York, the Dow Jones index opened with a fall of 0.38 percent, and the Nasdaq of 0.57 percent.
The benchmark price of WTI oil eased by 60 cents to $101.34 per barrel. Traders said that the market was waiting to see how the Ukraine situation and possible sanctions affecting energy markets evolved.
"It's been a very good couple of weeks for the markets, which have been buoyed by stronger than expected earnings reports from Europe and the US," Craig Erlam,market analyst at Alpari traders, said on Friday.
"While there may be an element of profit taking driving markets lower today, I think a bigger contributing factor is the recent flare up in eastern Ukraine and the war of words now taking place between the US and Russia."
Kiev has accused Moscow of seeking to set off a "third world war" by stoking border tensions, after a Russian military drill sparked stark warnings from the United States.
US Secretary of State John Kerry meanwhile said that the Kremlin is making an "expensive mistake" by meddling in Ukraine and a downgrade to one notch above junk of its credit rating suggested Moscow was already feeling the pinch.
- Alstom trades halted -
Trading in shares in French engineering group Alstom was suspended on Friday, a day after the stock had surged on rumours of a bid by US giant General Electric (GE).
On Thursday the price of shares in Alstom, which builds power stations and high-speed trains, shot up to show a closing gain of 10.93 percent to 27.0 euros.
This followed a report by financial news agency Bloomberg that GE, which is far bigger than Alstom, was in advanced talks to make a takeover offer valuing its target at about $13 billion (9.4 billion euros).
The French government said it was taking a "patriotic" view of the issues surrounding any such bid and was working on alternative solutions for Alstom.
In foreign exchange deals on Friday, the euro rose to $1.3843 from $1.3830 late in New York on Thursday.
It slipped to 141.33 yen from 141.53 late on Thursday.
The European single currency was steady at 82.32 British pence from 82.31 pence, while the pound gained to $1.6817 from $1.6801 on Thursday.
The yuan was at 6.2527 to the dollar, the lowest level since the end of October 2012, from 2.2504 on Thursday.
On the London Bullion Market, the price of gold edged up to $1,294.25 an ounce from $1,291.50 on Thursday.
Asian markets closed mostly lower on Friday, with another upbeat lead from Wall Street overshadowed by concerns about the Ukraine crisis.
US shares had ended mostly higher on Thursday following another round of impressive corporate results as well as a second strong month of durable goods orders in March.
The figures indicated the economy is rebounding from its winter slump.