Three years ago, when he stepped aside as chief executive of the internet group with which his name is intimately connected, Jerry Yang had a message for the Yahoo faithful: “I will always bleed purple.”

Mr Yang could hardly have come up with a more graphic way to express his love for the company he founded, along with fellow graduate student David Filo, on an idea for an index of websites that the two cooked up together in 1994.

Despite giving up the top job, however, Mr Yang remained on Yahoo’s board and had a powerful behind-the-scenes influence. Carol Bartz, who was forced out as chief executive last September, came to believe that Mr Yang was undermining some of her own efforts to turn round the company, according to people who know her. And when it came time to consider new strategic options after she had left, Mr Yang was the one who was sent out to talk to private equity firms about taking a stake in the company, though people close to the Yahoo board have insisted that he only did so under strict supervision from his fellow directors.