Supermarket retailer J Sainsbury said on Thursday that the role of chief financial officer John Rogers will be expanded to include business development as Helen Buck, who previously held the responsibility for this area, will step down from the operating board on 31 July.In his expanded role, Rogers will have responsibility for group strategy, Sainsbury's online, Mobile by Sainsbury's, Sainsbury's Energy, Netto and new business in addition to his existing responsibilities of finance, property, procurement, operational efficiency and Sainsbury's Bank.Chief executive Mike Coupe said: "John is a key member of the executive team and will play a major operational and strategic role in driving forward our business in his expanded role. In particular Sainsbury's online is a key component of growth in both our food and non-food businesses and I look forward to John's contribution in this area."At 09:56, shares were up 0.3% at 276.30p.