L.A. mayor Villaraigosa will not run for Barbara Boxer's Senate seat

After mulling a run, Los Angeles Mayor Antonio Villaraigosa decided to continue to focus on California, instead of pursuing the possibility of joining the United States Senate.

Former Los Angeles Mayor Antonio Villaraigosa, once considered a rising star in the Democratic Party, said on Tuesday he had decided against running for the U.S. Senate seat being vacated next year by the retirement of Democratic incumbent Barbara Boxer.

Villaraigosa, 62, widely believed to still be weighing a possible 2018 bid for governor, said in a message posted on Facebook that he wished to "continue my efforts to make California a better place to live, work and raise a family."

His decision to bow out of contention for the U.S. Senate leaves California Attorney General Kamala Harris, a fellow Democrat, as the clear front-runner to succeed Boxer in 2016.

California's lieutenant governor, former San Francisco Mayor Gavin Newsom, had been seen as a possible Senate candidate but he announced this month that he would run instead for governor in 2018.

The incumbent governor, Jerry Brown, 76, will leave office at the end of his fourth term in 2018 because of term limits. California's other U.S. senator, Dianne Feinstein, will be 85 when her current term ends in 2018 but has not said whether she would seek re-election.

Villaraigosa, a former California Assembly speaker who served as mayor of America's second-most populous city from 2005 through 2013, saw his reputation battered by an extramarital affair and criticism that he was ineffective in addressing many of the city's problems. (Reporting by Steve Gorman; Additional reporting by Lisa Baertlein; Editing by Eric Walsh and Mohammad Zargham)