"Today I'm withdrawing my candidacy for governor of California," Maldonado said at a news conference in Santa Maria, his home town. "Now is my time to step away."
Though no Republican is likely to unseat Gov. Jerry Brown in this heavily Democratic state, Maldonado was once thought the likeliest Republican to advance to the runoff against him in November. Many Republicans believed fielding Maldonado, a moderate Latino, could improve the diminished party's standing with Latino voters.
But Maldonado's support for temporary tax increases while in the Legislature alienated many conservatives, and his efforts to raise money fell flat.
Maldonado's campaign announced late Wednesday that he would make a "major announcement" at the news conference, but his advisers declined to comment ahead of the event. The Bee this morning reported he was quitting the race.
In exiting, Maldonado will record his third straight campaign failure. He lost his campaign for a seat in Congress in 2012 and, two years before that, his bid to keep his appointed post as lieutenant governor.
Maldonado's exit leaves Twin Peaks Assemblyman Tim Donnelly, a more conservative candidate, as the only Republican actively campaigning against Brown.
Neel Kashkari, a former U.S. Treasury Department official, is expected to declare his candidacy soon.
As part of his campaign, Maldonado announced last year that he would file a ballot initiative to repeal California's historic prison realignment, the 2011 law in which the state shifted responsibility for certain low-level offenders to counties.
No initiative has been filed, and Maldonado sidestepped a question about the initiative's future at his news conference Thursday.
"It just needs support, and I hope we can get that in the future," he said.
Editor's note: This post was updated at 11:48 a.m. to include Maldonado's remarks and reporting by Matt Fountain of The Tribune of San Luis Obispo.
Matt Fountain of The Tribune of San Luis Obispo contributed to this report.
PHOTO: Republican Abel Maldonado walks to a news conference in Sacramento on Wednesday, May 8, 2013. The Sacramento Bee/Hector Amezcua