* FTSEurofirst 300 index falls 0.1 percent
* Equity placings account for most heavily traded stocks
* Caution ahead of Ukraine, EU election results (Adds detail, quote, updates prices)
EDINBURGH, May 23 (Reuters) - French real-estate firm Gecina bucked the trend of low volumes in European share trading on Friday, as investors were kept cautious by an uncertain political situation heading into a long weekend for UK equity traders.
Gecina fell 1.8 percent in volume of twice its 90-day average after a share placing worth roughly 1 percent of share capital.
The real-estate investment trust was the most heavily traded stock relative to its 90-day average on the FTSEurofirst 300 , which saw trade across the index at a mere 30 percent of its average.
Mid-cap Danish jeweller Pandora fell 3.9 percent in trade of over 15 times its average following its own share placing.
Volumes were kept low as investors steered clear of big bets heading into a long weekend on the UK market, the biggest stock market in Europe, with ongoing uncertainty over elections in Europe and Ukraine.
The EU's marathon parliamentary election, which ends on Sunday, only affected share prices marginally, traders said. Britain's FTSE 100 mildly underperformed, down 0.3 percent, after its anti-EU UKIP party made strong gains in local elections.
Meanwhile, Dutch blue-chips slightly outperformed after a Dutch exit poll for the EU elections indicated that the anti-Islam, eurosceptic Freedom Party had fallen well short of its goal of topping the poll.
"Volumes are very low at the moment going into Bank Holiday weekend. The results we have seen to date in the elections are not a huge surprise, and have not led to any change in my view on the markets," Neil Wilkinson, European equities fund manager at Royal London Asset Management, said.
At 1124 GMT, the FTSEurofirst 300 index of top European shares was down 0.03 percent at 1,365.83 points after closing 0.1 percent higher in the previous session. The index climbed to 1,372.81 on May 15, its highest since 2008.
Russian shares came under pressure as tensions were high in Ukraine, where more than a dozen servicemen were reported killed on Thursday in a clash with pro-Russian separatists. Ukraine votes on Sunday in a presidential election.
Volume in Russia-exposed stocks, such as Renault, Raiffeisen Bank and Carlsberg, was especially light.
Analysts remained positive on the market's outlook, however, predicting that key European indexes would set new highs following expected new European Central Bank measures to support the economy.
"Markets remain well oriented. As (the) June 5 (ECB meeting) draws nearer, the market will start to anticipate about the European Central Bank's likely move to loosen its monetary policy. And that should be positive for risky assets," said Philippe Gijsels, head of research at BNP Paribas Fortis Global Markets in Brussels.
Analysts in a Reuters poll published on Wednesday expected the ECB to cut its main interest rate in June and push the deposit rate below zero in an attempt to stop the euro from rising and inflation from falling further.
Europe bourses in 2014: link.reuters.com/pap87v
Asset performance in 2014: link.reuters.com/gap87v
Today's European research round-up (Editing by Mark Trevelyan)