Real Madrid forward Gareth Bale, the world’s most expensive player, is close to signing a six-year, 20 million pound ($33.5 million) contract extension with sponsor adidas.The German sports retailing giant, which has had the 24-year-old Welshman on its books since he was 16, has been in talks with Bale’s advisers since he joined Real last summer for a world-record86 million pounds ($144 million).