Penn is developing the $390 million Hollywood Casino Jamul for the tribe. The company will manage the casino, located 20 miles outside downtown San Diego, when the property opens next year.
The promissory note had belonged to Golden predecessor Lakes Entertainment, which originally had a contract with the tribe. Las Vegas-based Golden merged with Lakes this year. Lakes wrote off the note in 2011.
In a statement, Golden said its expects to distribute proceeds of the sale to its shareholders and expects to record a gain on the transaction in its fourth quarter earnings.
"It has been our intention to monetize this noncore asset for the benefit of our shareholders," Golden CEO Blake Sartini said in a statement.