BRUSSELS (Reuters) - The economy, migration and international conflicts were the top concerns for voters in the European Union election, data from the bloc's biggest member countries suggested on Monday.

Provisional results in the European Parliament election on Sunday night showed gains for nationalist and euro-sceptic parties that campaigned on tickets including clamp-downs on migration, citizens' economic woes and scrapping green policies.

Improving the economy and reducing inflation ranked highest among citizens asked what was the most important thing influencing their vote, in a survey by polling platform Focaldata, shared with Reuters.

International conflict and war was the second most important concern, followed by immigration and asylum seekers, in the poll of 6,000 citizens in the EU's five biggest countries by population - Germany, France, Italy, Spain and Poland - plus Sweden.

The survey was done on June 6th, the day voting began in the EU Parliament election.

Respondents placed climate change fifth on the list of issues influencing their vote, behind "reducing inequality" which ranked fourth.

Europe's Green parties were among the biggest losers in the EU election, with initial results suggesting they would lose 18 seats to end up with 53 EU lawmakers.

However, climate change took the third spot in Sweden and Spain, the latter of which has suffered years-long droughts made more severe by climate change.

In France, Italy and Poland, voters said economic concerns were the main thing influencing their vote, with immigration in second place in France, and war the number two concern in Italy and Spain.

German respondents ranked immigration and asylum seekers as their top concern, followed by wars and then economic concerns.