His departure follows Littlewoods' decision to axe 60 IT staff from its home shopping division at the end of last year, after the company's £590m acquisition of Gus Catalogues in May 2003.
Littlewood's central IT department had already lost 66 jobs in March last year, as a result of the separation of the company's home shopping and high-street divisions following its takeover by the Barclay Brothers.
During his time at Littlewoods, Hallet oversaw the migration from more than 30 Hewlett-Packard servers to four Sun Microsystems boxes and the roll-out of a datawarehouse from NCR Teradata.
He was also responsible for bringing the retailer's e-commerce operation back in-house.
Neil McGowen, who Hallet had worked with at the former Gus businesses, will become head of group IT with immediate effect.