• by Steve McClellan  @mp_mcclellan, March 29, 2012

Monica Karo has been tapped to replace Andrew McLean as CEO of PHD US, the shop confirmed today. In addition, the agency is bulking up on senior management with the addition of two new positions, including a president of its New York office, Steve Williams, and a COO, Craig Atkinson.

Karo was previously president of integrated accounts at Omnicom Media Group, the media management arm that oversees both PHD and OMD. In her new role, Karo will continue her corporate duties overseeing media for the clients of Media Arts Lab, which includes computer company Apple Inc. MAL is a unit of TBWA/Chiat/Day, also an Omnicom shop.

Earlier, Karo served as president of OMD West. Before that, she held a number of senior positions at TBWA/Chiat/Day. Karo, who has been based in Los Angeles, will now split her time between L.A. and New York, where PHD is based. She will report to Page Thompson, North American CEO Omnicom Media Group, and Mike Cooper, global CEO of PHD. 

Williams has been CEO of OMD UK and is credited with overseeing its rise to the No. 2-ranked agency in the market. No word yet on who will replace Williams in the UK. Atkinson has been president and chief digital officer at PHD US. The agency said that he would retain his CDO duties while taking on the additional role of COO. Earlier, Atkinson ran the McDonald’s business at OMD.

Commenting on Karo's appointment, Thompson stated that she has had “an immense positive impact” on the clients and agencies she has served in the past, making her the logical choice to take on the leadership role at PHD.  

Thompson and Karo were busy talking to clients about PHD’s new management setup and were unavailable for live interviews Thursday.

News of McLean’s departure was reported earlier. Sources said that the agency decided to make a change after concluding that McLean’s management style clashed with PHD’s organizational culture. He joined the agency in December 2010. Previously, he had been worldwide chief business development officer at WPP’s media management arm GroupM.

McLean joined the shop as CEO of the PHD U.S. operation in December 2010. Previously, he had been worldwide chief business development officer at WPP’s media management arm GroupM.

On the business front, the agency did not do badly under McLean’s reign. During his first month on the job, the shop won the $1.4 billion U.S. GlaxoSmithKline account after a review that began well before he arrived at the agency. It also won clothing retailer The Gap that same month, with estimated global spending at the time of $350 million.

More recently, PHD US won smaller accounts, like VMware, but also the global $200 million Sony Ericsson assignment.

According to billings tracker RECMA, PHD had U.S. billings of $3.3 billion in 2011.

McLean had succeeded Scott Hagedorn at the agency. Hagedorn shifted to another Omnicom Media Group unit --  the Annalect Group -- a digital and data analytics agency.