Comet head of IS Kevin O'Brien is leaving the retailer to join independent IT consultancy Leading Resolutions.
After being at Comet for four and a half years, O'Brien has been replaced at the retailer by his former deputy Neil Verma, who was in charge of programme management, development and application support.
Verma has been in line to step up to the top job through established succession plans at the company, according to sources close to the company. He will be leading a 120-strong IT team at Comet.
The role will continue to report to Comet MD Bob Darke.
O'Bien's departure comes after completing work on a new web platform and transactional mobile system, including Apple and Andriod apps. During this time, the retailer also changed to a new payment service provider to improve customer service and reduce fraud.
O'Brien told CIO UK: "This was important to me and the MD to ensure a smooth hand over to Neil and also to ensure that the business had the best trading support possible, this was achieved with the online channel seeing significant growth."
Prior to joining Comet in 2007, O'Brien was divisional IT director at Mothercare, where he worked for five years and also was IT director at Virgin Retail for one year.
Comet was unavailable for comment.