BBH was appointed by Jim Hytner, ITV's former marketing director, and had handled the business for more than three years. However, the two parties have split two months after the arrival of Clare Salmon as Hytner's replacement and one week after M&C Saatchi was appointed to handle a project evaluating the ITV brand.
Salmon said in the medium term the creative account will be handled by ITV's roster of small agencies as she oversees the media pitch, although a formal review may follow.
A BBH statement said: "We are proud of the work we have done for ITV but we are not able to continue the relationship from here on. We wish ITV every success in the future. A successful ITV is very important for us all."