Founded in 2008 by a team led by chief executive Andy Center, 56, CloserStill produces trade shows for the health and technology sectors. International sales reached £9m last year, helped by events such as Cloud Expo Asia, a cloud computing event in Singapore. In 2015, private-equity firm Inflexion bought a minority stake for an undisclosed sum. This helped fund the acquisition in January of French company iLearning Forum, which organises one of Europe’s largest elearning conferences.