Boxing legend Muhammad Ali has reached an agreement to sell 80% of the rights to use his name and likeness to

CKX

(CKXE)

, a company that buys ownership interests in entertainment stars and brands.

Ali will retain a 20% interest in the commercial rights to his name and image, which will be operated through a newly formed company named G.O.A.T. LLC. G.O.A.T. stands for "Greatest of All Time," a reference to Ali's nickname. The Muhammed Ali Family Trust received a cash payment of $50 million from CKX for the stake.

New York-based CKX also owns the rights to the name and likeness of Elvis Presley and the Idols television brand, including the "American Idol" television show.

Born Cassius Marcellus Clay in Louisville, Ky., Ali first achieved fame by winning the boxing gold medal at the 1960 Rome Olympics. He changed his name when he converted to Islam. He was eventually a three-time heavyweight fighting champ, and finished his professional career with a record of 56-5.

After he left boxing, he was diagnosed with a form of Parkinson's disease, and he's now known as an advocate for various humanitarian causes.

Shares of CKX were down 32 cents, or 2.3%, to $13.57 Tuesday.