Danny Sullivan, Internet search guru and founder of Search Engine Watch (SEW), has announced that he is to leave the website he started.

A series of sales left the company controlled by Jupitermedia, which founded the Search Engine Strategies (SES) conferences, a series of industry get-togethers focusing on the challenges of navigating and understanding search engines.

Jupitermedia in turn sold both the website and the conference series to Incisive Media, a company Mr Sullivan himself admits to having failed to agree terms with.

Writing on his own blog, daggle.com, Mr Sullivan said: "I'm far from the only reason behind the success of SEW and SES, but I've played a major role. I helped build both of those assets."

"Then I watched one company sell them to another without me having any formal capital stake in the sale. That left me wary of history repeating itself. I wasn't going to help this new company grow the business out of the sheer kindness of my heart."

SEW started life as the publication online of a small study Mr Sullivan conducted into how web designers could best target their sites through web searches.

He will remain as editor-in-chief of SEW until the end of November this year, with SES appearances beyond those in Los Angeles and Chicago this year possible, but unlikely.