Hilton's shares were up 6.3 percent at $24.35 in premarket trading on Monday.
HNA will buy the stake for $26.25 per share, representing a premium of 14.6 percent to Hilton's closing price on Friday and valuing the hotel company at about $26 billion.
Blackstone's holding in Hilton will be reduced to 21 percent after the deal closes in the first quarter of 2017, the companies said.
Hilton Worldwide's brands include Conrad Hotels & Resorts, Curio and Double Tree as well as Hilton.
The deal comes after China's Anbang Insurance abandoned its pursuit of Hilton rival Starwood Hotels & Resorts Worldwide in April following a bidding war with Marriott.
Marriott completed the acquisition of Starwood in September to create the world's biggest hotel chain.
Evercore is the financial adviser to Hilton, while JPMorgan advised HNA Group.