According to BMB, the two parted ways because of creative differences.
Purplebricks is now contacting agencies with the brief and has said in statements to the press earlier this year that it intends to invest more heavily in marketing.
Juliet Haygarth, BMB’s chief executive, said: "We take pride in what we do and how we do it. Unfortunately with Purplebricks, it became clear that our creative differences and ways of working were too far apart. We wish them well in the search for a new creative partner."
Purplebricks describes itself as a hybrid estate agent, meaning it predominantly operates online but also has "local property experts" who can talk to customers.