It has told Mr Sterling that there will be a hearing on June 3, at which he will be able to address the league’s 29 other owners before they vote on whether to terminate his ownership of the Clippers.
Three quarters of the owners must vote to end Mr Sterling’s ownership, along with that of his wife.
Mrs Sterling initially had said she would fight to keep her 50 per cent share of the team even if her husband is forced to sell, but the league has made it clear that all ownership interests in the Clippers will be terminated if the other owners vote to sever his control.
Donald Sterling’s attorney Max Blecher had asked for a three-month delay, but the league has rejected this request.
Mr Blecher had originally said his client would refuse to pay the fine and was considering suing the NBA.
The woman who recorded Mr Sterling making the comments has claimed it was just one of many she had made of their private conversations, with his permission, as a form of self-help therapy.
“The purpose of the recording was for him to learn things about himself, for me to show him things about himself that sometimes he didn’t want to believe and accept,” Ms Stiviano said on American television show Dr Phil.
“I would play those things back to him just to remind him of how he acted or how offensive he can be toward another person.”
Mr Sterling has denied that he knew he was being recorded, and said Ms Stiviano had “baited” him into making provocative remarks, which Ms Stiviano denies.
She also denies that she had anything to do with publicising the recording.
She said it was either given or sold to gossip website TMZ by an unnamed friend to whom she had, for unspecified reasons, entrusted a copy of the tape.