Clear Channel has been strategically firing employees in small numbers so it doesn’t appear that the company is undergoing large-scale layoffs, he said, adding that it would have looked bad for Mr. Romney if his former company fired Clear Channel’s workers en masse.

“They’ve been nipping and tucking a lot since last November,” Mr. Del Colliano said. “There has been a substantial number of people [let go]. I can’t estimate it, [but] a handful of people every week for 52 weeks.

“It’s my belief that what they wanted to do was keep attention off of their Bain founder, Mitt Romney.”