BRUSSELS, June 4 (Reuters) - Luxembourg Prime Minister Jean-Claude Juncker will surrender his finance minister post and so step down as head of the 16-member Eurogroup of euro nations, an official at Juncker's ruling party said on Thursday.
If his party wins national elections on Sunday and Juncker secures another term as prime minister, he will recommend that Budget Minister Luc Frieden take the finance minister post, CSV administrator Paul Weimerskirch said.
"It's a surprise for us equally. We thought it was a rumour for a week, and he confirmed it last night," Weimerskirch said. (Reporting by Anne Jolis, editing by Dale Hudson)