King, who worked at Haymarket Business Media for nine and a half years, launching RSVP magazine and then working on industry publications Event and Media Week, will be replaced at The O2 by Barney Hooper, currently head of communications at PRS for Music.
In his new position, which he will take up on 3 June, King will be looking after C Squared’s M&M Global offering, which targets the global advertising market. He will also be in charge of the company’s Cream brand, as well as creating content and sourcing speakers for its Festival of Media events in Miami, Rome and Singapore.
King told Event: "I have had an amazing 18 months as communications director at The O2, which has involved implementing a strategic communications strategy, winning a host of awards for the first time, and generating coverage across a variety of media.
"However, the lure of heading back to editorial and the opportunity to guide C Squared’s content into its next chapter was just too exciting to turn down."
King stepped down as editor of Event magazine in November 2012.
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