Kevin Allchorne, the global managing director of Amlin's global reinsurance division, has stepped down from the role for personal reasons but remains with the company.
A spokesman from Amlin said the hope was that he would remain with the firm but his future role was unclear at this stage.
The company will be recruiting to replace him. In the meantime, Dominic Peters, head of reinsurance for the UK and Asia-Pacific and joint active underwriter at Amlin, and Rob Wyatt, the underwriting director of Amlin Bermuda, will jointly lead the North American and International regions while a replacement is sought.
Christian Bieri continues to lead the EMEA region. Simon Beale, the group chief underwriting officer of Amlin, retains overall responsibility for the role, the spokesman said.
Allchorne was appointed as global managing director of Amlin's global reinsurance division in September last year. He has been with the business for 26 years holding a number of senior roles prior to this.