A JWT spokeswoman declined to comment.
Mr. Murphy, 42, was most recently deputy chairman of London-based Bartle Bogle, which is known for the strength of strategy underpinning its creative campaigns. At JWT, he will collaborate closely with worldwide creative chief Craig Davis, and will work on global brands and projects, as well as oversee planners around the agency's global network.
One of his first charges: to develop a planning process and tools for use throughout the WPP Group network. In his global role, Mr. Murphy takes on duties held most recently at JWT by David Lamb, now executive director-marketing at JWT client Diamond Trading Co.
Mr. Murphy joined Bartle Bogle in 1992, was appointed to its board in 1995, headed planning in Asia Pacific for four years beginning in 1997; moved in 2001 to London to head European planning; and was named deputy chairman in 2004.
Nearly 40 years ago, with a department led by noted strategist Stephen King, JWT helped introduce the notion of planning to the ad industry. Account planning, created in the mid-1960s, is an approach to generate consumer insights that are used to develop strategy and tactics for ad campaigns.