The appointment marks a return to the agency world for Ostler, who left MindShare Digital for an 18-month spell as a director of The Accelerator Group, a multi-channel retail investment firm.
She replaces Jeremy Davies, who followed former JWT CEO Stephen Carter to NTL.
Ostler said, "It was fascinating to take a step back into an advisory and financial funding role, consulting to other people on how best to run their businesses. I am now looking forward to bringing that experience to digital@jwt and the stimulation of leading a team again."
During her time at MindShare Digital, Ostler worked across a wide range of clients including Bol.com, Haymarket Group, British Interactive Broadcasting and Boots. As head of digital communications for O&M, she lead a team responsible for key accounts, including IBM, Guinness, Ford and Unilever.
Simon Bolton, CEO of JWT London, said, "We firmly believe in digital communications and see an enormous opportunity in a technology platform such as the net to keep brand communications fresh and relevant to deliver great results. J Walter Thompson obviously wants to secure the sharpest knowledge and experience it can offer its clients, and digital@jwt is imperative to maintaining its edge in this sector."
Ostler began her career in digital media in 1993, when she became a media communications planner for Chiat Day London before moving to O&M.
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