Brazil '.65 recorded for both Atlantic & Capitol:
https://www.discogs.com/artist/1237687-Sérgio-Mendes-Brasil-65
Per: https://en.m.wikipedia.org/wiki/Sérgio_Mendes#:~:text='" Alpert and Moss signed Mendes,Brasil '66" with A%26M.
All of Mendes' jazz albums for Atlantic Records, through Nesuhi and Ahmet Ertegun, had low sales. Richard Adler suggested that Mendes and the group sing in English, as well as Portuguese as Mendes had demanded, and Adler sought new English-based material such as "Goin' Out of My Head" by Teddy Randazzo and Bobby Weinstein. In order to sing these songs properly in English, Adler suggested that the group find two American female singers who would sing in both English and Portuguese. Adler called his friend Jerry Dennon and A&M Records founders Herb Alpert and Jerry Moss, and arranged for an audition for Mendes' new group, which was dubbed "Brasil '66.'" Alpert and Moss signed Mendes and his group to A&M Records.[3] Adler then went to the Ertegun Brothers at Atlantic Records and sought to have them release Mendes from his Atlantic Jazz contract. Ahmet agreed to allow him to record albums under the name "Sergio Mendes and Brasil '66" with A&M. Mendes was not at this meeting, only Adler and Ahmet Ertegun. Alpert took over as producer for the A&M albums, and the group became a huge success with their first single, "Mas que Nada", by writer Jorge Ben.
So it would appear that "Brazil '66" technically got signed by A&M, not Mendes, although his release from his solo Atlantic contract fixed that.
Ah, show biz!!?