Berlin  - The leadership of Germany's Social Democrats, who suffered a stinging election setback a week ago, nominated a 50-year-old outgoing minister, Sigmar Gabriel, as new party leader on Monday, sources said.

The choice was made behind closed doors at a Berlin meeting of the party's innermost leadership and will be put to a national conference in Dresden next month, where adoption of leadership decisions is usually a certainty.

The sources told the German Press Agency dpa a vote within the 15-member presidential committee of the national executive to replace the key leadership positions went through with one abstention and no opposition.

The full 45-member national executive was to vote on the issue next. Leftists in the party voiced anger that the leadership question had been settled by a small circle and not opened to wider debate.

A talented debater, Gabriel was briefly premier of the German state of Lower Saxony. He is set to succeed Franz Muentefering as party leader.

Gabriel remains Germany's environment minister until the federal election victors, Chancellor Angela Merkel's Christian Democrat bloc and the Free Democratic Party, set up a new coalition government.

The Social Democratic Party (SPD) won only 23 per cent of the vote on September 27, down 11 percentage points from four years ago.

Andrea Nahles, a leftist woman, was nominated as general secretary of the party in the committee meeting. Foreign Minister Frank-Walter Steinmeier is to become leader of the opposition, as head of the SPD parliamentary group in the Bundestag legislature.  dpa