LONDON--David Gallagher has been named CEO of Ketchum Pleon Europe, succeeding Timo Sieg who will depart at the end of the year.

Gallagher, currently senior partner/president of Ketchum Pleon Europe based in London, ascends to the role two years after Ketchum merged its European operations with German-led firm Pleon. Dirk Popp will continue in his role as CEO of the agency’s key German operation.

“Now that David and I have completed two years of operating together and have Dirk in place as CEO of Germany, it is time to turn European leadership over to David Gallagher,” said Sieg. “I have worked closely with David and Dirk and I know they will continue to achieve great success by focusing on meeting our clients’ demands and growing the firm’s talent. In addition, I will continue to provide senior counsel to our clients. I am now ready to take time off and prepare for new opportunities ahead.”

The integration of the two firms has not been without its challenges, particularly in Germany where some senior executives, most notably former CEO Frank Behrendt, have departed. Sieg has been associated with Pleon, and its previous incarnation ECC Kohtes Klewes for more than a decade, and was appointed chairman and CEO of Pleon in 2006.

Popp will lead the the firm’s executive board in Germany, which consists of Christiane Schulz, partner and managing director of the Berlin office, and Horst Wettlaufer, CFO of Ketchum Pleon Germany.

“Timo has been a strong business partner,” said Ketchum senior partner and CEO Ray Kotcher. “His accomplishments have provided an excellent foundation to grow Ketchum into the industry leader across Europe and become the stronger, more geographically diverse, more creative firm it is today.”

Gallagher takes charge of Ketchum Pleon’s operations in 39 cities across the UK and continental Europe. The American joined Ketchum in 1994, moving to its London office in 2000.