A former Brooklyn federal prosecutor was appointed yesterday to serve as a special bias monitor for the FDNY to help ensure non-whites in its ranks are treated fairly.

Mark S. Cohen, who has been a partner in a Manhattan law practice since 2002 after a previous stint as an assistant US attorney, was tapped by Brooklyn federal Judge Nicholas Garaufis for the court-mandated post.

Cohen will have substantial authority to oversee hiring, training and promotions of minorities in the 11,000-person FDNY, the nation’s largest fire department.