BRUSSELS, June 17 (Reuters) - European Union leaders met on Monday to discuss who to nominate to the EU's top posts following a European Parliament election and were set to back Ursula von der Leyen for another term as head of the European Commission.

In addition to reaching an informal agreement on von der Leyen, they will discuss who should be EU foreign policy chief and the next president of the European Council, which brings together the 27 national leaders to set the EU political agenda.

Von der Leyen is on course for a second five-year term as president of the powerful EU executive after her centre-right European People's Party (EPP) won the most seats in the European Parliament election this month, with 13 of the 27 EU leaders from parties in the EPP.

As the big EU states France and Germany have already offered her their support, von der Leyen, a German, will have the qualified majority she needs to be nominated.

The centre-right finished ahead in the election overall despite gains for right-wing nationalists and setbacks for the parties of liberal President Emmanuel Macron in France and Socialist Chancellor Olaf Scholz in Germany.

"I am quite sure that we will be able to reach an understanding between the political families, but also the countries in Europe, in a very short time and have proposals (on the top jobs)," Scholz said on arrival for the informal talks in Brussels, the leaders' first gathering since the election.

France had previously weighed alternatives to von der Leyen, but with a snap parliamentary election called by Macron from June 30, the government now prefers EU stability.

Antonio Costa, a Socialist former prime minister of Portugal, is set to become the next president of the European Council, a position which would see him chairing EU summits from December.

Estonian Prime Minister Kaja Kallas, a liberal, is in line to be nominated as the high representative for foreign affairs, ensuring a balanced geographical and political spread of jobs across the bloc.

The leaders' are due to confirm their choices at an EU summit on June 27-28. Von der Leyen would still then need backing from the European Parliament, which votes in its first session from July 16.

The full 27-member European Commission, including the foreign policy chief, also needs the European Parliament's backing.

The EU leaders were also expected to discuss the next five-year legislative cycle, with a stress on common values, defence and economic competitiveness. They are due to confirm their "strategic agenda" guidance at a summit later this month.

(Additional reporting by Sarah Marsh in Berlin; Reporting by Philip Blenkinsop; Editing by Jan Strupczewski, David Holmes and Timothy Heritage)