Sainsbury's shares fell over 3 percent shortly in early trade on Wednesday. The group's stock price has struggled over the last 12 months, and is down over 30 percent since the start of the year. They recently hit a six-year low after rival Tesco reported a £250 million ($405 million) accounting error. Read More UK watchdog launches investigation into Tesco J Sainsbury Chief Financial Officer Mike Rogers told CNBC that the supermarket's results were strong in the context of a "very tough market."