Fantasia & Brandy -- Ex-Publicist Claims Sony FIRED Me 'Cause I'm Black

Fantasia and Brandy have been caught in the middle of a racial war ... ignited by their former publicist who claims their music studio hates black people and that's why he lost his job.

Courtney Barnes -- a well-known publicist -- was hired by Fantasia a year ago, but fired days later. Barnes claims in his lawsuit her manager told him a V.P. at Sony hated him and wanted him gone.

Barnes claims he was told the V.P. came on so strong ... he threatened to screw Fantasia over if she didn't drop Barnes.

Now here's what Barnes says is the smoking gun. He claims in the lawsuit the Sony V.P. -- Sarah Dennison -- formed her opinion about Barnes based on hearsay that he had a reputation for "shady business practices."

Barnes insists in his lawsuit ... "shady business practices" is code for racism. He also claims the only interaction he ever had with her was a handshake on one occasion. So he says if she didn't know him, how could she form her opinion?

Barnes says the firing ruined his career, claiming it impacted Brandy's decision not to work with him ... based on Dennison trashing him to the singer.

Barnes is now suing Dennison and Sony Music for ruining his reputation and stressing him out. He claims he would have made $250K had he not been fired.