"Placing an executive of Ross's calibre in charge of Ansible is a true measure of the important role Ansible plays in our Mediabrands business and its future potential," said IPG Mediabrands Australia chief executive Danny Bass.
Raeburn joined Mediabrands two years ago and has been serving as CEO of the UM Australia business, where he has done an "outstanding" job, according to Bass.
He was previously managing director of Soap Creative after joining that company as head of digital strategy. Earlier in his career Raeburn worked for Yahoo7 as head of community, and for Pacific Magazines as online manager.
Bass will take on the UM Australia CEO role on an interim basis until a successor for Raeburn has been appointed.