Acevo is looking to appoint a new head of finance following Mal Lewis's announcement that he will depart after only five months with the chief executives association.
Lewis will join the Juvenile Diabetes Foundation as director of finance.
Acevo says it will appoint an interim head of finance to cover Lewis's departure in the immediate future, before it recruits a permanent replacement.
Lewis joined Acevo at the end of May. The organisation cited "career development" as the reason for his decision to leave.
"We are grateful for all Mal has done in his time with Acevo and wish him well in his new post," said David Hunter, policy and development officer at Acevo.