The US advertising holding company is accusing Sir Frank of using confidential and proprietary information relating to clients and staff, gained when he was head of its Lowe Worldwide agency network.
It says he is now using this information to set up his own agency, which has already poached the 拢42m Tesco account from Lowe.
As well as luring away the Tesco account, Sir Frank is being joined by Lowe London chairman Paul Weinberger and two creatives from the Tesco account, Sam Cartmell and Jason Lawes. Executive creative director Ed Morris also looks set to leave Lowe to join the start-up agency.
In a statement, Interpublic said: "Frank Lowe sold his agency to Interpublic in 1990 for tens of millions of dollars and subsequently received many times that amount in financial support and resources to build a global network, recruit and compensate key talent.
"Our claim states that, in breach of his continuing fiduciary responsibilities, he has chosen to use contacts and proprietary knowledge to damage Lowe and Interpublic. We will be asking the panel for monetary compensation and injunctive action. We also intend to hold any Lowe employee seeking to join Mr Lowe to their full notice period."
It plans to take the case to the American Arbitration Association, which specialises in resolving management-labour disputes.
Along with Lowe Worldwide, Interpublic owns agencies including McCann Erickson, media agency Initiative and Foote Cone & Belding. It has been going through a tumultuous period since revealing it had incorrectly reported earnings dating back to 1996. Last year, it reported a loss of over half-a-billion dollars for 2004.
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