Allan's departure represents the latest senior management change at troubled Kingfisher. It follows the appointment of Ian Cheshire to replace Rob Cissell as B&Q chief executive last week.
Screwfix Direct has had a difficult year after a distribution centre move hampered customer order fulfilment.
But a Kingfisher spokesman said the reasons for Allan's departure were career-related and geographical rather than because of recent Screwfix problems. 'He wants to move to Scotland and pursue a portfolio career with a mix of consultancy roles and non-executive positions,' said the spokesman.
He explained that Allan's decision to leave pre-dated the arrival of Cheshire at B&Q. Allan is replaced by B&Q managing director of supply chain and services Steve Willett. He in turn is succeeded at B&Q by Martin Lee.