Obama and Romney spar over Bain Capital
US President Barack Obama's and White House rival Mitt Romney have sparred over Mr Romney's record during his years at a private equity firm.
The Obama video features former workers of a steel plant bought and later shut down by Bain Capital, the company co-founded by Mr Romney.
"It was like a vampire. They came in and sucked the life out of us," one former GST Steel employee says.
The Romney campaign later released its own ad featuring steel workers.
Mr Romney has repeatedly attacked the president for failing to create jobs.
The former Massachusetts governor's pro-business credentials are seen as a core part of his campaign message.
The rebuttal video featured workers at a mill under Bain Capital management, highlighting what the campaign said was Bain's success in reviving struggling businesses.
"When others shied away, Mitt Romney's private sector leadership team stepped in," a voiceover said.
Battle is joined
Correspondents say Obama's two minute-long negative ad is set to be broadcast in five battleground states - Iowa, Ohio, Pennsylvania, Virginia and Colorado.
The campaign also issued a six-minute online-only version and launched a website specifically aimed at criticising Mr Romney's record.
Mr Obama's political allies and surrogates are also expected to denounce Mr Romney's track record as a private equity executive at a series of campaign events.
The new ad echoes a theme used earlier in the year by a group supporting former presidential hopeful Newt Gingrich.
A half-hour video called When Mitt Romney Came To Town , which appeared in January at the height of the primary battle, portrayed Mr Romney as a "corporate raider" who destroyed thousands of jobs while amassing large profits.
At the time Mr Gingrich was criticised by members of the Republican establishment, who described the video as "anti-capitalist".
The Romney campaign derided Mr Obama's anti-Bain message as an "attack on free enterprise".
"The President should be more concerned with helping the twenty-three million Americans who are struggling for work," Romney spokeswoman Andrea Saul said.
At a New York fundraiser on Monday evening, Mr Obama spoke out in favour of the free market, calling it "the greatest wealth-generator ever devised by man".
College tuition concern
The campaign ad wars are beginning to heat up as the Obama and Romney campaigns embark on the six-month march towards November's presidential election.
On Sunday both teams released videos marking Mother's Day , and the fundraising committee Crossroads Generation, which supports Mr Romney, released a campaign video focusing on the problem of growing student debt.
Correspondents say the Crossroads video is an effort by Republicans to engage younger voters, many of whom backed Mr Obama in 2008.
The video was released hours before Mr Obama delivered the commencement address at the women's Barnard College, where he told students that despite lingering high unemployment, he was convinced opportunities for women would continue to grow.
"As tough as things have been, I'm convinced you are tougher," he told the graduates.
In a statement, the Romney campaign said the president's "gift" to graduating students was "record debt and a struggling economy".