Siewert will continue to work with a number of BMF clients as he transitions fully to TLE, where he will report to Chrissy Blackburn, global head of strategy.

Prior to BMF, Siewert was senior brand communications planner for Vodafone Ireland.

Earlier in his career, he was strategic planning director for AKQA New York, brand strategy director at Naked Communications in London, and European account director then department head for strategic and creative intelligence at Abbott Mead Vickers BBDO London.