French, who was CEO of Prism Media prior to its $530 million acquisition of Penton last year, has recently made some difficult and unpopular decisions at the struggling b-to-b publishing company.
In April, he instituted salary and hiring freezes, and in June eliminated 42 positions at Penton.
In the memo, he said: “My leaving is truly the next step in a significant transformation, which is already well under way across the organization. New leadership from the CEO position will help bring new thoughts and new ideas to Penton.”
He will stay in his position until a successor is identified and is working with the board of Penton to find a replacement. He will also continue to serve on Penton’s board.