Juncker was chosen as the lead candidate of the conservative center-right European People's Party (EPP) at a party congress in Dublin. A veteran of EU politics, the former Luxembourg prime minister lost office last year after 18 years in the position.

Juncker beat French rival Michel Barnier, the EU's regulation chief, with a first tally among EPP delegates showing he secured 382 votes to Barnier's 245. Delegates included German chancellor Angela Merkel.

The EPP hopes to remain the strongest in the European Parliament after May's elections, despite a challenge from the Socialists. Friday's vote puts Juncker, also the first president of the Eurogroup of eurozone finance ministers, in the front running for the EU's most influential job, with oversight on legislation affecting 500 million people.

The European Commission is the EU's executive body which proposes legislation and plays a role in making sure the 28 member states adhere to the bloc's laws.

As the largest political grouping in Europe, with 74 parties from 39 countries, the EPP currently heads the European Commission with Jose Manuel Barroso and the European Council with Herman Van Rompuy. Barroso is stepping down after 10 years in the job.

Before receiving the EPP's backing, Juncker told delegates that he was "a true European."

"I want to be the president of the next commission," he told the party congress.

Other candidates

Juncker will face off against the Socialists' candidate, German politician and European Parliament president Martin Schulz, and former Belgian prime minister Guy Verhofstadt, the choice of the liberal Alliance of Liberals and Democrats for Europe.

Other candidates include the Greens' double ticket of Germany's Franziska Keller and France's Jose Bove, while Alexis Tsipras, the leader of Greece's opposition party SYRIZA, has been nominated by the far left.

This year is the first time that Europe's political parties have nominated their candidate for the European Commission president, in a move to counter traditionally low voter turnout and boost interest in the elections.

Polling indicates either the Social Democrats or the EPP will come top in the European Parliament elections, and the group that does will have the first attempt to secure parlimentary backing for Commission president.

jr/ph (dpa, AFP, Reuters)