Broker WestLB Panmure reiterated its sell recommendation on J Sainsbury (4p off at 330p) ahead of Monday's launch of Nectar, its new loyalty card. Analyst Philip Dorgan says Nectar appears quite impressive, but it is once more a case of 'certain cost' (the £40m marketing campaign), but 'uncertain' benefits. He does not think shoppers will abandon Tesco (3 1/2p dearer at 220 1/2p) to seek Nectar points.