NEW YORK—MSLGroup has hired Edelman's Ron Guirguis as CEO of its US operation, the latest in a series of senior changes at the Publicis Groupe PR network.

Guirguis' arrival comes shortly after Guillaume Herbette was named global CEO of MSLGroup, in a bid to improve integration between the firm and its Publicis siblings.

Former FleishmanHillard executive Herbette took on the role after outgoing CEO Olivier Fleurot moved into an SVP position at Publicis Groupe in late June. Arthur Sadoun, CEO of ad agency Publicis Worldwide, took on supervision of MSLGroup, bringing in Herbette as the firm's new CEO.

Guirguis effectively becomes MSLGroup's fourth US head in less than four years. Paul Newman stepped down from his role as North American CEO following Fleurot's exit, after just 18 months in place.

Newman succeeded chief client officer Renee Wilson, who took charge of MSLGroup's North American operation following a difficult period, which included a class action lawsuit and the departure of Americas chief Jim Tsokanos in 2012. Wilson relinquished the role at the start of 2014, with former eBay exec Newman arriving shortly afterwards.

"Ron’s strong client experience and proven leadership skills have made him a natural choice to take MSLGroup to the next level in the US, working with our teams to deliver the very best for our clients," said Herbette. "He has the heart and courage to help MSLGroup take on the biggest client challenges and the tenacity to see them through."

Guirguis, who has led Edelman's corporate and public affairs practice in New York since 2012, previously spent 13 years at FleishmanHillard.