Gavin Newsom drops out of California governor race

San Francisco Mayor Gavin Newsom attends a rally at City Hall with hundreds of police and firefighters urging the city's board of supervisors to protect public safety services and hold off the elimination of firehouses in San Francisco, California June 16, 2009.

SAN FRANCISCO (Reuters) - San Francisco's Democratic mayor, Gavin Newsom, withdrew on Friday from next year's race for California governor.

"With a young family and responsibilities at city hall, I have found it impossible to commit the time required to complete this effort the way it needs to -- and should be -- done," Newsom said in a statement.

His withdrawal leaves Jerry Brown, the state's attorney general and a former governor, as the leading Democratic contender to succeed Republican Arnold Schwarzenegger, who is prohibited from running again by California's term-limits law.

(Writing by Mary Milliken; Editing by John O'Callaghan)