Ian Derbyshire has left struggling travel agent Thomas Cook.

The former head of retail at the tourism giant will be replaced by Simon Robinson, currently Thomas Cook managing director of e-commerce.

The move comes at a sensitive time for Thomas Cook, as the agent seeks to complete a merger with Co-operative Travel and Midlands Co-operative to create the largest UK travel retailer.

Derbyshire follows Manny Fontenla-Novoa out of the door, with the former chief executive stepping down earlier this month.

However, it is believed Derbyshire’s departure was agreed some time ago.

In a statement he said: “Leaving will be a wrench, but those who know me know how my family come first.”

Derbyshire is the latest in a series of senior managers to depart.

Richard Calvert, managing director of mainstream tour operations, announced he was quitting in late June, while e-commerce private labels director Andy Washington switched to Expedia in May.