Danny Sullivan, editor of Search Engine Watch (SEW), is leaving both the site and Search Engine Strategies (SES) conference series (via Marketing Pilgrim).

Sullivan today announced on his blog Daggle that after more than 10 years of writing online about search, his contracts with Incisive Media, the owners of the two properties, are expiring. Apparently, after a year of negotiations Sullivan and the company could not agree on new terms. "I love both the site and the conference series. I hate to say goodbye to them," Sullivan wrote.

Sullivan in 1997 sold SEW to what became Jupitermedia, which last year sold both SEW and SES - along with ClickZ - to Incisive.

"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," Sullivan wrote.

"I explained…that I needed some long-term incentive for helping them (Incisive) continue to grow and strengthen the site and conferences. After over a year of talks, that's failed to materialize. As a result, I'm departing."