stax (and satellite, before stax), volt & enterprise were never part of the atlantic records corp, inc.
jim stewart's account of ahmet ertegun's response when - pretty mildly, all things considered - reproached for not, eventually, putting matters right may also be instructive, as well as very definitely germane.
Atlantic owns nearly all the Stax-Volt masters that were issued up until May 1968, save for a few singles and albums that were only distributed in and around Memphis. Jim Stewart and Estelle Axton must have not read the fine print in the contract telling them that it was a master purchase deal, and only found this out in early 1968 when trying to renegotiate their distribution with Atlantic. Consequently, they sold out to Paramount, leaving behind their back catalogue (and also Sam & Dave's contract, which was apparently directly with Atlantic).
I agree with ppint! I've always thought some of the tracks are of Stax origin, Booker T, Otis R., Bar-Kays, Carla T. to name a few!!! But then Stax Records were Part of the Atlantic Corporation,
As did the likes of Volt, Atco, Etc. at the time