President Barack Obama asked major corporations for their help in putting the long-term unemployed back to work.

CEOs from companies like Apple, Walmart, Visa and Boeing were at the White House on Friday to deliver commitments to do their part. More than 300 companies have signed on so far.

Although the unemployment rate has declined to 6.7 percent, long-term joblessness in the U.S. remains a major problem. The concern is that the longer someone is out of a job, the harder it gets to find a new one. Companies are less likely to hire people who haven't used their skills in months or wonder why another employer hasn't already snatched them up.

With that concern in mind, the Obama administration has been working for months to exact commitments from companies to ensure their hiring practices don't discriminate against long-term job-seekers.

That includes doing away with candidate-screening methods that disqualify applicants based on their current employment status. It also means ensuring that jobs ads don't discourage unemployed workers from applying.

The White House couldn't say how many unemployed Americans might benefit from the initiative but expected the effects to snowball.

"We consider this not the destination, but the launch," said Gene Sperling, who heads the White House's National Economic Council. "Our hope is that as people see the meeting with the president, the pledge, that more will come work with us."

Among the companies taking part: Rupert Murdoch's News Corp. and 21st Century Fox. Sperling said he emailed the conservative business mogul about the initiative, and Murdoch personally wrote back to say he supported it.

Obama also signed a presidential memo Friday directing the federal government to apply the same standards to its own hiring practices. And the Obama administration will direct $150 million in grants toward partnership programs that retrain, mentor and place unemployed workers.

The initiative marks the latest attempt by Obama to use what executive authority he has to improve economic conditions for Americans despite a political climate that makes enacting his legislative agenda nearly impossible. In the past, Obama has supported legislation in Congress that would make it illegal for employers to discriminate based on one's employment status or history.

"In terms of legislation. Let's face it: That's not going to happen," Sperling said.