By Lily Kuo

WASHINGTON (Reuters) - The White House pledged on Wednesday to help lower-income youth find summer jobs in a move likely to appeal to younger voters crucial to President Barack Obama's re-election campaign.

The initiative is in partnership with the cities of Philadelphia, Chicago and San Francisco and is meant to add 110,000 jobs, internships and mentorships to the 180,000 summer work opportunities for 16-24 year olds that Obama has promised to create for 2012.

Under the new program, companies such as Blue Cross and Blue Shield Association, Johnson & Johnson, and UBS, as well as non-profits and federal agencies such as the Department of Education will offer paying jobs as well as mentorships and other training programs.

Every year from April to July, the size of the youth labor force swells as high school and college students nationwide look for summer jobs. But summer employment for young job seekers has hit record lows in recent years as more of them are unable to find work, according to data from the U.S. Bureau of Labor Statistics.

"There's no replacement for the dignity that comes with earning your first paycheck," said Secretary of Labor Hilda Solis in a statement.

The initiative, which does not require congressional approval, comes on the heels of Obama's multi-state visit to college campuses where the president stressed his effort to get Congress to extend low interest rates on college loans to more than 7.4 million students.

Obama won a strong majority of the youth vote in his 2008 presidential election and is trying to do so again but a key question is whether many young people will turn out to vote.

The White House said the city of Chicago would provide 973 jobs through a partnership with Chicago Public Schools where nearly half of the opportunities would be offered to students at risk of academic failure.

In 2011, the number of young people looking for but unable to find summer work increased by 745,000 to 4.1 million in July, which is typically the peak of youth employment. Last summer also marked the lowest rate of youth employment for the month of July since 1948, according to the labor bureau.

(Editing by Barbara Goldberg and Greg McCune)