Supermarket giant Tesco has been hitting the headlines of late after the discovery of a £250m accounting error and continued concern from investors about falling sales and reduced profitability. Yesterday it was reported that investor Warren Buffet has cut his stake in Tesco to less than three per cent, in response to the retailer's plummeting share price, telling CNBC: "I made a mistake on Tesco. That was a huge mistake by me."