[London] Ben Langdon, regional director of Europe, Middle East and Africa, Interpublic Group of Cos.' McCann-Erickson WorldGroup, is leaving his post to "pursue other opportunities," the agency said. Mr. Langdon, 39, joined McCann in 1996 as chief executive of the London office. He was promoted to regional director in 2001. McCann said there are no plans to fill the position. Mr. Langdon's responsibilities will be assumed by David Warden, a regional director of operations in London.