The agency said it was moving into new media because of the increasingly important role it played in the marketing mix.
Tetteh-Lartey has eight years' experience in the new-media industry and has worked on clients including Tesco Personal Finance, Highland Spring and Visit Scotland.
Yvonne Balfour, managing director of Navigator, said: "In common with most agencies, we had in the past outsourced digital work, but we now believe that new media is playing such an increasingly important role in the marketing mix that we want to build and develop our own in-house resource."
Navigator has developed campaigns for clients such as Remy Martin, F&C Asset Management, De Vere Resort Ownership and Dumfries & Galloway Tourist Board.
In December 2004, the agency became part of Cello Group, the AIM listed marketing services group that also owns The Leith Agency and Target Direct.
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