U.S. Labor Secretary Hilda Solis, the first Hispanic woman to serve in a Cabinet, joined the exodus from President Barack Obama's administration as he prepares for a second term.

"I have decided to begin a new future, and return to the people and places I love and that have inspired and shaped my life," Solis, 55, said yesterday in a letter to the more than 17,000 employees in the agency.

Solis, one of eight women among 23 Cabinet-level officials, follows Secretary of State Hillary Rodham Clinton and Environmental Protection Agency chief Lisa Jackson in announcing their departures. The president plans to name White House Chief of Staff Jack Lew tomorrow to be Treasury secretary, replacing Timothy F. Geithner, a person familiar with the process said.

Other posts to be filled include Commerce secretary, the U.S. trade representative and director of the Office of Management and Budget. Attorney General Eric Holder, Health and Human Services Secretary Kathleen Sebelius and Veterans Affairs Secretary Eric Shinseki all plan to remain for at least part of the next term, according to a White House official, who asked for anonymity because the decisions haven't been announced.

Solis, a U.S. representative from California from 2001 to 2009, as Labor chief focused on expanding job-search services and skills training to combat mounting U.S. job loses. Since 2009, more than 1.7 million people completed federally funded job-training programs, she wrote in her letter. Of those, more than one million have received industry-recognized credentials.

'Critical Member'

The agency’s mission is to promote programs to help workers and retirees, oversee compliance with wage and workplace safety rules and compile employment statistics.

Obama credited Solis, daughter of a Mexican father who was a Teamsters shop steward and Nicaraguan mother and assembly-line worker, with helping to put millions of Americans back to work.

"Secretary Solis has been a critical member of my economic team as we have worked to recover from the worst economic downturn since the Great Depression," Obama said in a statement. "Her efforts have helped train workers for the jobs of the future, protect workers' health and safety and put millions of Americans back to work."

The White House statement didn't identify a successor. According to published reports, possible candidates include former Michigan Governor Jennifer Granholm, who recently ended the talk show she was hosting on Current TV, and former Representative Betty Sutton of Ohio, who lost her re-election bid in November. Liz Boyd, a spokeswoman for Granholm, declined to comment on the speculation.

'Create Jobs'

"While Secretary Solis and I often disagreed on the best way to create jobs and jump start the economy, I wish her the best as she departs the Obama administration," Representative Phil Roe, a Tennessee Republican, said in an e-mail. "My hope moving forward is that President Obama will find someone for the position who supports all workers' rights, promotes economic growth and is willing to work in a bipartisan way to create jobs."

Solis was confirmed by the Senate Feb. 24, 2009, as the 25th labor secretary. Her nomination won bipartisan support after Republicans ended efforts to delay a vote over questions about her ties to union groups and tax liens on her husband's business. The vote was 80-17.

Assembly Line

Solis's father, a Mexican immigrant, was a shop steward with the International Brotherhood of Teamsters. Her mother, from Nicaragua, was an assembly-line worker and a member of the United Rubber Workers. She has been an opponent of free-trade agreements, in step with union positions. She voted against trade accords with Central America nations.

"Secretary Solis has been an exemplary public servant and a fierce champion for workers' rights," Senator Tom Harkin, an Iowa Democrat and chairman of the Senate Health, Education, Labor and Pensions Committee, said in a statement. "She served as a strong voice at the Department of Labor during a particularly challenging time for our nation's economy and for our middle class."

During her tenure, U.S. unemployment climbed from 8.3 percent when Solis took office in February 2009 to 10 percent in October, according to data compiled by Bloomberg. The rate was 7.8 percent in December, according to the Labor Department.

AFL-CIO Reaction

"Secretary Solis never lost sight of her own working-class roots, and she always put the values of working families at the center of everything she did," said Richard Trumka, president of the AFL-CIO, the nation's largest labor federation, in an e-mailed statement. "We hope that her successor will continue to be a powerful voice both within the Obama administration and across the country for all of America's workers."

In her letter to Labor Department staff, Solis cited department efforts to improve worker safety. In 2001, there were the fewest-ever U.S. mine fatalities, she wrote. Fatalities in industry and construction are at "historic lows," she added.

Solis also highlighted efforts to ensure that people are paid what they are owed.

"Last year we conducted the largest number of investigations in recent memory, collecting the most back wages in our history," she wrote. "In these recoveries, what may seem to some as small change makes a huge difference for those who live paycheck-to-paycheck."