The 75-year-old, who has donated to both the Republican Party and the Romney campaign, also said it was unfair to focus on instances where Bain executives benefited from leveraged buyouts, in which companies acquired by Bain later collapsed and filed for bankruptcy.

“Business is a risk-reward proposition,” said Bain. “For over 28 years, Bain Capital has invested in many great success stories and some failures.”

But, the businessman said, "most importantly, [Bain Capital] has maintained an overall record of creating significant value for our economy.”

The Obama campaign and its allies have made attacking Bain a central tenet of their critique of the Republican nominee. Earlier this week, Priorities USA, the super-PAC supporting President Obama's reelection campaign, released a new ad slamming Romney over his tenure there.

“Mitt Romney is making promises to the American people in the same way he made promises to the thousands of middle-class workers whose lives were devastated by his business decisions,” said former White House official and Priorities USA senior strategist Bill Burton in a statement. “If Romney claims his business experience is the reason he should be elected president, it's important that voters know the impact that experience already had on thousands of middle-class families.”