Blackstone Group LP bought, Hilton Worldwide Holdings Inc. in 2007 and now plans to raise $2.4 billion in its U.S. IPO, the most ever for the hotel company. Hilton Worldwide plans to sell 112.8 million shares for $18-$21 each. The world's largest hotel company with over 4,000 properties plans on selling 64.1 million shares, its hopes of paying off $1.25 billion in debt. Blackstone wants to take Hilton public after the company refinanced $13 billion of debt, through U.S. stocks hitting record highs and a rebound in hotel occupancies and rates.