Kotcher, 60, will take a chairman role overseeing Flaherty. He has led the firm for 12 years after succeeding David Drobis in a similar succession in 2000.
Ketchum has set up a web page, ketchumleadershipchange.com, about the transition.
Dale Adams, who heads Omnicom’s Diversified Agency Services Group, which houses Ketchum alongside PR units like Fleishman-Hillard and Porter Novelli, said Kotcher developed the Ketchum brand into one of the group’s most successful companies in the PR sector. He said Flaherty “has a deep belief in the power of communications and its ability to affect change.”
Flaherty joined Ketchum in 1989 from Burson-Marsteller. Earlier, he was director of PR for the F.X. Matt Brewing Company in upstate Utica, N.Y.
Ketchum was sold to Omnicom in 1996.
The CEO change was announced a week after sister agency Porter Novelli said it would replace CEO Gary Stockman.