NEW YORK (Reuters) - Celebrity socialite Paris Hilton won't likely get a windfall from the $20 billion sale of Hilton Hotels Corp., the source of her family's fortune.

Paris and other descendants of her great grandfather Conrad Hilton -- who started the hotel group in 1919 when he bought a small hotel in Cisco, Texas -- are expected to get little from the buyer, private equity firm Blackstone Group.

That's because the family has little stake left in the company and what's remaining is expected to ultimately go to charity.

"Very few Hiltons will benefit very much from this sale," said Jerry Oppenheimer, who profiled the Hilton family in his 2006 book "House of Hilton."

Hilton Co-Chairman Barron Hilton, Conrad's son and Paris' grandfather, is the only member of the Hilton clan that has a sizable role at the company. He's expected to give the roughly $1 billion that he stands to get from the sale of his 5.3 percent stake to the Conrad N. Hilton Foundation.

The foundation supports projects that provide clean water in Africa, education for blind children, and housing for the mentally ill. Its aims, based on Conrad Hilton's will, are "to relieve the suffering, the distressed and the destitute."

"Barron made a pledge that he was going to abide by his father's wishes (and leave his money to his father's foundation)," said Oppenheimer.

The sale of the hotel company, which manages more than 2,800 hotels in 76 countries, comes with the low-key, 79-year-old Barron Hilton seeking to cement his business legacy, even as his partying granddaughter fills gossip columns.

"Barron wanted to go out a hero. That's the kind of guy he is," said Oppenheimer. "He was going to make sure this company was sold at a huge profit before he died."

"He was, and is, extremely embarrassed by how the Hilton name has been sullied by Paris," said Oppenheimer. "He doesn't want to leave unearned wealth to his family."

Representatives the Hilton family weren't immediately available for comment.

Paris, a symbol of celebrity privilege in America, gained notoriety in 2003 when a home video of her having sex was posted on the Internet.

She parlayed her notoriety, fueled by tabloid headlines about her partying lifestyle, into a celebrity career that has included a reality television show, a book, a music album, and film roles.

Last month, she was released from jail after about three weeks for violating probation in a drunk-driving case.

"If it wasn't for Paris, no one would be talking about the Hilton name. It would just be a financial story," said Oppenheimer.