Legendary basketball owner Ozzie Silna -- who along with his brother made the GREATEST deal in the history of sports -- has died ... TMZ Sports has learned.
The 83-year-old titan and his brother Dan became sports business gods -- reportedly making $800 MILLION from the 1976 sale of their ABA team, the Spirits of St. Louis.
The long story short ... Ozzie and Dan -- who had previously made a fortune in the textile industry -- played hardball with the NBA during the ABA-NBA merger negotiations.
Instead of taking a $3 million lump sum deal to fold their team, the Silnas negotiated for a portion of the NBA's TV rights ... which they owned in PERPETUITY.
The Silnas had made $300 MILLION from the deal over the years ... but reportedly agreed to sell their rights back in the NBA in 2014 -- for an ADDITIONAL $500 MILLION!!!
We spoke with Dan Silna ... who told us Ozzie passed after a "short illness."
He told us, "Ozzie Silna was one of the most honest and moral people you'll ever meet. He was one of the most straightest shooters you'll ever meet. The world has lost a great guy."