Thomas Neslon, taken private almost exactly four years ago in a $473 million deal, announced today that an investor group led by Kohlberg & Company has acquired a majority of its stock. According to Nelson, the investment “will significantly improve the company’s capital structure and eliminate the majority of its long-term debt.” InterMedia Partners had led the Nelson buyout in 2006, and they maintain a minority interest.

With its investment, Kohlberg has appointed a number of new board members including former HarperCollins CEO and cofounder of Open Road Integrated Media Jane Friedman. Kolhberg is a major backer of Open Road, having invested over $7 million in the venture. As CEO of HC, Friedman oversaw Nelson’s major competitor, Zondervan. Also named to the board was Nelson’s current CEO Michael Hyatt who was named chairman (Hyatt had acted as chairman of a smaller board).

No terms of the deal were announced. When InterMedia bought Nelson, for a significant premium over its stock price, it obtained $219 million in debt financing that included a six-year $199 million term loan and a five-year $20 million revolving credit facility. In addition, it had a seven-year $73 million senior loan.

Since the 2006 acquisition, Nelson has undergone almost a complete overhaul, most notably eliminating all of its imprints and reorganizing its publishing functions around consumer categories in April 2007. The company also endured two rounds of layoffs in 2008-2009 as the company reacted to the recession and its decision to release significantly fewer titles. According to a spokesperson, Nelson had EBITDA in the low double digits in the fiscal year ended March 30.