Bad news for Kareem Abdul-Jabbar ... the NBA legend has been ordered to pay more than $900k to a famous auction house for backing out of a deal to sell a bunch of his memorabilia ... TMZ Sports has learned.
Kareem had been at war with Julien's Auctions for years -- after a 2012 deal to sell 400 items went south. Kareem went to the auction house in 2014 and physically removed some of the items.
Julien's sued Kareem -- claiming they also made a $300k donation to his foundation as part of the deal to sell the items -- but he refused to refund the money when he backed out of the sale.
The case went to arbitration ... and Kareem lost.
Now, he's been ordered to pay more than $900k in damages PLUS interest and attorney's fees. He's also been ordered to return all the items he took.
Julien's president and CEO, Darren Julien, issued a statement saying, "It is very unfortunate that it had to come to this as we tried everything to come to an agreement with [Kareem and his manager] outside of the courts."
We reached out to Kareem's manager for comment -- so far, no word back.