The Chief Executive of UK Athletics, Niels de Vos, is to step down at the end of September after 11 years in charge of the organisation.
Nigel Holl, the current Strategy and Partnerships Director of UK Athletics, will assume the role on an interim basis until a permanent successor is found.
During De Vos' time at UK Athletics, the organisation hosted the IAAF World and World Para Championships, as well as establishing the Anniversary Games and the newly-launched Athletics World Cup.
"Niels has been a fantastic servant to not only UKA, but the sport of Athletics as a whole," said Richard Bowker, Chairman of UK Athletics. "The sport has grown and been hugely successful under his leadership.
"Today's announcement is the culmination of a number of months dialogue about his ambitions to set up his own business. He leaves with our enormous thanks and we wish him well for the future."