When Oracle appointed him as CFO in June, Larry Ellison called him an "exceptional executive." Now, just 5 months later, Greg Maffei (pictured) is a departing executive. In fact, he is the second successive Oracle CFO to resign less than a year after beginning in the role, giving rise to all sorts of speculations among analysts and commentators since Oracle Co-President Safra Catz, in taking over as interim CFO, will in fact be the fourth CFO the company has had in the past 2 years.

Oracle chairman and CEO Larry Ellison said in a statement: "Greg has told us he's looking at a terrific professional opportunity. We wish him well."

So why would a CFO leave one of the world's major software companies just 5 months after joining it? Maffei characterized it as a matter of not being in the line of succession for Ellison's chief executive chair:

"Oracle's a great place, a great opportunity, but they have a fantastic CEO and they're likely to have that CEO for a long time. It was not only a case that he was not leaving, but I was not the obvious heir apparent.''

There was talk this week that perhaps the "terrific professional opportunity" was just a smokescreen for some kind of Sarbanes Oxley-type irregularity that Maffei didn't want to become associated with. (Post SOX, being a CFO is no cakewalk.) But it also entirely possible that Maffei - a former CFO of Microsoft, no less - has been tapped as CEO of a major company and simply wanted to swap his $900,000 or so a year at Oracle for something even more attractive.