Best Buy shares tumbled 14 per cent yesterday, their biggest decline in more than eight years, as the biggest US electronic retailer reported an unexpected third-quarter dip in profit. The company also cut its outlook after decreased demand for televisions, notebook computers and videogames took its toll on sales. Net income in the fiscal third quarter, which ended 27 November, fell four per cent to $217m (£137.4m), or 54 cents per share, from $227m, or 53 cents per share, last year. Analysts had expected 61 cents per share. Revenue fell one per cent to $11.89bn, from $12.02bn last year. Analysts expected revenue of $12.45bn.