The percentage of working-age Californians with jobs has fallen to a record low, and employment may not return to pre-recession levels until the second half of the decade, according to a research group.

Just 55.4 percent of working-age Californians, defined as those 16 or older, had a job in July, down from 56.2 percent a year earlier and the lowest level since 1976, the Sacramento-based California Budget Project said in a report released late Saturday.

California’s 12 percent unemployment rate in July, the nation’s second-highest after Nevada, compared with 9.1 percent nationwide. The most-populous state lost 1.4 million jobs during the recession that began three years ago, and has gained back only 226,800, or about 17 percent, according to the report.

Alissa Anderson, deputy director of the research group, which concentrates on issues facing low- and middle-class Californians, said women have disproportionately trailed men in regaining jobs.

“Women represent nearly half of the workforce,” Anderson said in a telephone interview. “They gained just one of the 10 jobs added.”

Job losses in local government, health care and other industries where women make up a large portion of the workforce contributed to the weak employment picture. Women have lost jobs in industries such as retail and financial services, while men in those fields gained.

“As businesses cut costs, the first thing to go is administrative support positions where women tend to work,” Anderson said.