Private equity has moved from the “golden age” of record-sized buyouts to the “purgatory age,” when firms need to atone for their so-called sins of success, Carlyle Group co-founder David Rubenstein joked on Friday at the Warton Private Equity and Venture Capital Conference.

After a protest by the Service Employees International Union briefly delayed Rubenstein’s speech, he said “The golden age is over. We’re now in the purgatory age.” The SEIU labor group was protesting Carylyle’s recent acquistion of nursing home operator Manor Care , saying the buyout firm’s pressure for greater profits would worsen care for senior citizens and conditions for employees.

“P/E firms will spend more time explaining what we do to create value. No body ever asked me in the past what jobs we created or what factories we opened…or why P/E firms make companies more efficient and what we do to create value beyond the rate of return,” Rubenstein said.

The private equity industry will have to address the concerns of labor unions, Congress and the media more than in the past as greater attention gets focused on how buyout firms conduct business, he said.

Although tight credit markets have made mega-deals difficult to finance, Rubenstein said the industry will see more smaller deals and non-leveraged deals in which buyout firms take minority stakes in companies. Private equity will also invest more internationally. But buyout firms shouldn’t take a bleak view on the current market tensions since times of economical turmoil often create the greatest opportunities for deals, he said.

“After the purgatory age, we’ll see the platinum age,” Rubenstein said. “The problems with financing and the problems explaining what we’re doing will go away…private equity is better than anything you can legally do with your money.”

Rubenstein, who in December bought a rare, 710-year-old copy of the Magna Carta for $21.3 million, urged conference attendees to be more involved in community service and philanthropy. The historical document, the last remaining copy in the United States, will remain on permanent display at the National Archives and Records Administration, Rubenstein said.

“Always think of meaning for society and the community in which you live and give back to that community, as well as your families,” Rubenstein said.

Maybe that’s the way out of purgatory?

(Photo: Reuters/Fred Prouser)