Bere has spent the past three months working at BMB on a freelance basis. His full-time appointment reunites him with the BMB co-founder Trevor Beattie, with whom he worked at TBWA\London, and the Carling account, which BMB won from Leith London in February 2006.
Beattie said: "I've known Simon for many years. He's an absolute class act, one of the finest writers in the business. His contribution to BMB's creative output over the past few months has resulted in us securing several new-business wins, most notably Ikea."
The appointment is the second senior creative hiring at the agency in two weeks. Last week, BMB poached the Fallon creative team of Matt Doman and Ian Heartfield.
Bere worked on campaigns including Sony PlayStation, Nissan and Absolut at TBWA, before becoming the agency's creative head of new media.