Portuguese finance minister Mario Centeno said on Tuesday he was stepping down from his post and would also not be seeking another mandate as head of the Eurogroup.
Centeno has headed the Eurogroup, a framework for meetings of eurozone finance ministers, since December 2017.
Centeno will formally announce his resignation from the Eurogroup during a meeting of eurozone finance ministers on Thursday, he said.
His Eurogroup term was to end next month, and he would not seek another, he said on Twitter.
Centeno said he would now invite applications for his job, with a vote on his successor planned for July 9.
German Finance Minister Olaf Scholz said on Tuesday that Centeno had "done a very successful job", including by contributing to "a whole series of advances" in the European stability mechanism and the banking and capital markets union.
As for his choice of successor, Scholz said "this is not a time for speculation".
"But I can tell you that I and the German government have a clear vision."
According the EU sources, current finance ministers likely to be interested in succeeding Centeno include Pierre Gramegna of Luxembourg, Nadia Calvino of Spain and Ireland's Paschal Donohoe.
France's Bruno Le Maire is not interested in the job, the finance ministry in Paris said.
The Eurogroup chief's mandate runs for 2.5 years.
Former German finance minister Wolfgang Schaeuble once called Centeno the "Cristiano Ronaldo of the EcoFin", the EU's economic and finance committee.
But insiders say that Centeno had been a disappointment to his colleagues who complained about what they felt was a lack of charisma and authority.
His time at the Eurogroup "has not been a smashing success, to say the least", tweeted Lucas Guttenberg of the Jacques Delors institute in Berlin, a think tank.
"This also ends a chapter that made the EG more and more irrelevant," he said. "The next Eurogroup president needs a plan how to make the EG useful again -- or we can shut it down."
Centeno had been rumoured to be preparing his departure as Portugal's finance minister for some months, with speculation rife that he wants to head up his country's central bank next.