The elder Hilton, 80, said he would give 97% of his $2.3bn (£1.15bn) estate to the Conrad N. Hilton Foundation, a charity founded by his father.

"We are all exceedingly proud and grateful for this extraordinary commitment," said the head of the charity, Steven Hilton, who is Barron's son and an uncle to Paris.

"Working to alleviate human suffering around the globe, regardless of race, religion or geography, is the mandate of the foundation set by my grandfather ... and now reinforced by my father."

The charity has distributed more than $560m for programmes that assist mentally ill homeless people, tackle substance abuse and increase access to safe water in Africa and Mexico. A significant portion of the money helps the work of Catholic sisters.

Some of the money will come from the sale of the Hilton Hotels group - which was founded by Conrad Hilton when he bought a small hotel in Texas in 1919 - to a private equity firm, the Blackstone Group.

According to one recent book about the Hilton family, Barron Hilton has been embarrassed by the behaviour of his socialite granddaughter, who gained notoriety through a homemade sex video and has since served time in prison for violating probation on a driving ban.

He has pledged an immediate $1.2bn to the charity and an estimated $1.1bn to follow after his death.

He had indicated at a recent board meeting that he would follow in the footsteps of his father, who left nearly all of his fortune to the trust when he died in 1979.