[Update, 3 pm: EXCLUSIVE: Asia a major focus for new McCann Boss Diamond]
Harris will hold the title of chairman and CEO. Luca Linder, president of McCann Worldgroup, Americas and Gustavo Martinez, president of Europe, have been given broader roles, each adding geographic responsibilities and full oversight of McCann Erickson Advertising.
In his new role, Linder will add Middle East and Africa responsibilities while Martinez will add Asia-Pacific responsibilities to his current title.
Linder and Martinez will also join Diamond in a newly created, three-person office of the chairman for McCann Worldgroup.
In an internal memo, it was announced that Andy Polansky, president of Weber Shadwick, has been named to replace Diamond as CEO of the PR agency.
"In recent years, we’ve invested in terrific talent across the organization and we will continue to do so in order to build on the progress we’ve been seeing at Worldgroup,” said Michael I Roth, Interpublic’s chairman and CEO.
Diamond, added Roth, understands the business needs of global CEOs across a range of industries and has a proven track record of effectively managing a portfolio of agencies and growing the top line.
"He has created a strong culture of collaboration, which is increasingly key in a marketing landscape that requires integration of services, and he brings a deep knowledge of McCann in light of the alignment between Worldgroup and a number of the agencies within CMG, such as Weber Shandwick and FutureBrand," concluded Roth in a statement.
On Brien's departure, Roth's only comment was to thank Brien for his "commitment and for driving change at McCann during his tenure.”
We will be updating this story shortly with further details.