Sepp Blatter says he will step down as Fifa president in 2015, if he is re-elected for a fourth term in June.The 75-year-old, who has been head of world football's governing body since 1998, is being challenged by Asian confederation chief Mohamed Bin Hammam."I am a candidate for the next four years as Fifa president but these will be the last four years for which I stand as a candidate," said Blatter.The new president will be elected at a Fifa Congress which starts on 31 May.Source: BBC