Marks & Spencer suffered another setback this week when the head of its food business unit quit. Roger Whiteside is leaving to join LM Solutions, a company set up to seek internet opportunities in the European food markets. M&S said no sucessor had been appointed and it would now look outside the business for someone to oversee the food operation. Whiteside left this week along with Nigel Robertson, the divisional director who was personally appointed as the "head of change" by Marks & Spencer's chief executive Peter Salsbury. Robertson ­ who has been reviewing the work of consultants Arthur Andersen ­ is also joining LM Solutions. M&S said it regretted their decisions but said the duo had been offered a "once in a lifetime" opportunity. {{NEWS }}