Pardon joined Aegis Media in a consultancy role early last year, before taking the title of chief trading officer.
A spokesman for Aegis Media confirmed Pardon had "left the company by mutual agreement to pursue other interests".
Industry sources suggest Pardon was brought in to champion best practice among Aegis Media’s global divisions and align their trading more closely, but that this was hampered because of internal politics and tensions.
The Aegis Media spokesman declined to comment on whether internal tensions were a factor in Pardon's departure, but sources close to Aegis insisted his departure was by mutual consent due to an initially agreed contract coming to an end.
Prior to Aegis, Pardon was at rival operator WPP until 2009. After joining Mindshare in 2004 to lead the agency's Unilever account in Europe, he also took on the role of GroupM trading director for Europe, the Middle East and Africa.
Earlier in his career, Pardon was managing director of ITV sales house Granada Enterprises, but lost out when ITV managing director of sales Graham Duff appointed Gary Digby in the role of sales director of the merged ITV sales house in December 2003.
Pardon, in sales since 1993, was group sales director at Granada Enterprises before moving to the managing director role. He also had stints as executive sales director at Laser Sales and agency sales director at Granada Television.
He started his career on the media agency side at Zenith Media in 1988 and moved to Carat International to take on the role of international media director in 1991.
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