The move is not a direct swap. Phillips was sales and marketing director, while Slattery who was ad manager at the paper will stick to a sales role.
Slattery, who was ad controller at the Daily Express before joining City AM for its launch in September last year, will oversee a team of 12 as the paper seeks to expand its consumer advertising, which to date includes campaigns from Sony PlayStation2, Nikon and business campaigns for Blackberry, IBM and Lufthansa.
Lawson Muncaster, managing director of City AM, said: "Slatts is a terrific chap. The results he has delivered so far, the team he has built and his vision for our revenue generation going forward all prove that he deserves to step up to a full and formal sales role.
"City AM has had an encouraging start and we are comfortably on track for our target to break even in year two. Jeremy has played a big part in our success."
Phillips has left the company by mutual agreement to pursue his other business interests. Phillips helped launch the title along with Slattery.
David Parsley, editor of City AM has been nominated for the title of business journalist of the year at the London Press Awards, alongside former Economist editor Bill Emmott and Chris Blackhurst of the Evening Standard.
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