Dear oh dear, it's the four-year nadir...The value of Vodafone shares this morning continued to languish at a four year low after falling more than six per cent yesterday. By 09:30(BST) Vodafone shares were into the red by a further four per cent to 82.50p - down almost 60 per cent on its 52-week high. As the biggest telecoms stock on the FTSE100, Vodafone's dip dragged the index down with it by 52.6 points, or just over one per cent. Vodafone's poor stock performance was hit further yesterday by the slump in Vivendi's share value. According to the Financial Times Vodafone has expressed an interest in the media giant's mobile phone unit.