Byrne, previously group corporate communications director, has been handed the top marketing role at the Prudential-owned online bank, after chief marketer Nick Cross left without a job to go to.
As well as overseeing PR and communications, Byrne will develop Egg's brand, advertising and research functions. She reports to chief executive Paul Gratton.
Byrne joined Egg in 2000 from PR firm Weber Shandwick, where she specialised in retail and financial services.
Egg retains agencies including Agency Republic, Claydon Heeley Jones Mason, Mother and MediaCom.
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