FORTUNE — John Simon is leaving General Catalyst Partners, a Cambridge, Mass.-based venture capital firm he co-founded back in 2000.
His investments have included Bullhorn (acquired by Vista Equity Partners), BzzAgent (acquired by Tesco), Maven Networks (acquired by Yahoo) and Taleo (taken public, later acquired by Oracle).
Simon confirmed his departure to Fortune, emailing over the following statement:
Amicable sentiments, but sources suggest that the situation was a bit more complicated.
Simon co-founded the firm with three other venture capitalists: Joel Cutler, David Fialkow and David Orfao. When Orfao quietly cut back on some of his management responsibilities a year or two ago, it basically left just three co-founding decision-makers, with Cutler and Fialkow having known each other since childhood.
Soon Simon began finding himself on the short side of several decisions, and broader strategy moves like General Catalyst’s strong push into seed-stage Silicon Valley consumer deals (he felt there should be more focus on deep-tech opportunities closer to the firm’s Massachusetts roots).
“It was a combination of things, but leaving now lets John continue to stay involved with his portfolio companies and find something new to do,” one source says. “He just turned 50 and has been with General Catalyst for a long time. Sometimes people just need to go their separate ways.”
No word yet on Simon’s future plans, except that he doesn’t seem to have finalized them yet. Do expect him to continue seed investing, which he already had been doing at General Catalyst.
I also haven’t heard if General Catalyst plans to promote anyone to assume Simon’s managerial responsibilities, although word is that managing director Hemant Taneja stepped into some of those roles when Orfao stepped back.
A General Catalyst spokeswoman did not return a call requesting comment.
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