The executive will remain in his position until March 31 and an external search for his successor is underway.
"This label will be a portal to the underground club world, distilling future trends for mass consumption," said Dollimore.
McCartney joins as agent while Frankel will serve as marketing and branding lead.
Fernández previously served as president of Noticias Telemundo, the news division of the Spanish-language network, from 2015-2021.
The London-based executive has been with the company since 2012.
Also this week: Ryan Seacrest ain't going anywhere, an Amazon Music star departed but has Nothing planned and new leaders are in place at the Guild of Music Supes.
The company also promotes Alan Rogozin to DADP general manager and ups Aidan Flynn, Jordan Dempsey and Marcus Greenstein to agents.
The mogul has been the subject of several recent lawsuits alleging sexual abuse.
Also this week: Neon Records' chief steps down and C.A.M.P. 615 adds a CMT veteran.
A new board will replace the one that axed Altman on Friday.