The 37-year-old quietly left the WPP agency at the end of last year to become managing director of McCann Erickson's 20-strong media department in Birmingham.
Murphy, who lives in Warwickshire and is expecting his second child this month, cited the international requirements on the Zurich account for Mindshare as a key factor in his departure.
Murphy said: "It soon became apparent that the international aspect required more time than any of us thought.
"Mindshare is a great agency which made it such a difficult decision but I had to put my family commitments first.
"The McCann Erickson role is one I applied for before the Mindshare job came up and I am thrilled to be able to fulfil my ambitions within such a challenging agency in Birmingham."
Murphy joined the WPP agency in September 2009 after five years at Publicis Groupe's Zed, the last two years of which he was joint managing director.
He was responsible for developing the agency's product and client offering in the direct and digital space at a UK and European level, and reported to Lucy Stafford, managing director of Mindshare Direct in the UK, and Worldwide chief strategy officer Nick Emery.
Jed Glanvill, chief executive of Mindshare UK, wished Murphy well and said he will not be replaced directly although there had been a restructure at its international Zurich team following his departure.
In his new role at McCann Erickson, Murphy reports to Dean Lovett, chief executive of McCann Erickson.
This article was first published on mediaweek.co.uk