Here is a clear definition of
ex-officio on
http://www.businessdictionary.com/definition/ex-officio.html..."Holding a position or membership due to the power or influence of one's office, and
not by election or appointment. A chairperson, for example, can be an ex-officio member of all board appointed committees. Such positions and their attached voting and other privileges are detailed in the bylaws of the organization. Latin for, because of one's office."
I was not entirely correct by suggesting that
official could work, but it's not too far off the ballpark. Of course, we're not in the business of merely being not too far off, but rather of being as precise as possible.
The meaning is closer to
by right of one's position,
by right of one's appointment, or simply
by right. Of course, none of these are as succinct and widely used as
ex officio, and 100% of Linguee results seem to attest to that.
peer agreement (net): +6