Members of Berlin's main governing party have chosen the city's development minister to be its new mayor after the charismatic and long-serving incumbent announced his resignation.

The center-left Social Democrats said Saturday that Michael Mueller won 59.1 percent support in a membership ballot. He was far ahead of two rivals — local party chairman Jan Stoess with 20.9 percent and Palestinian-born caucus leader Raed Saleh, who won 18.6 percent.

Mayor Klaus Wowereit plans to step down Dec. 11 after over 13 years in power, two years before his term expires. He was long popular but his reputation suffered from persistent delays in opening Berlin's new airport.

The Berlin state parliament will elect his successor. Since a Social Democrat-led coalition has a majority there, Mueller is all but guaranteed the job.