Weil, Gotshal & Manges is advising Chinese conglomerate HNA Group Co. on a $6.5 billion investment in Hilton Worldwide Holdings Inc.—a move that will give HNA a 25 percent stake in the U.S.-based hotel empire.

HNA is buying its stake from The Blackstone Group, which will keep a 21 percent stake in Tysons Corner, Virginia-based Hilton once the deal completes in the first quarter of 2017.