Gesua was promoted to the role of managing director of BlowUp Media UK.
He is being replaced by Katrin Robertson, group managing director at BlowUp Media, who is moving from Germany to the UK to help oversee the business.
Robertson will take over the day-to-day running of the business, while "succession plans are considered", the company said.
Robertson has been with BlowUp Media since 1995, and was appointed to the group managing director role in 2007.
It is unclear if Gesua, who joined the company in 2001 which specialises in large outdoor formats, has left with a job to go to.