When Sir Howard Stringer joined Sony in 1997 nobody, including the Welsh-born executive, could have foreseen that he would rise to be a candidate for the top job at the Japanese electronics and media giant.

At the time Sir Howard, then plain Mr Stringer, had just left Tele-TV, an ill-fated attempt by several large US telecommunications groups to set up a rival to the cable TV industry. Although he was officially president of Sony's US operations, he had no direct responsibility for any of the group's main businesses in the United States: the heads of both Sony Music and Sony Pictures reported directly to Tokyo.