Paris Hilton's grandfather will hand over 97% of his $2.3 billion fortune to charities when he dies.

Barron Hilton has overlooked his 23 grandchildren - including Paris and sister Nicky - and bequeathed 97 per cent of his estimated $2.3 billion fortune to his father's charity - the Conrad N. Hilton Foundation.

In a statement released on Wednesday, the charity's chief executive officer Steven Hilton commented: "This generous donation means that the work of the foundation will continue and expand for many years to come."

Barron made an immediate donation of $1.2 billion to the foundation, and the other $2.2 billion will follow upon his death.

Paris, 23, has so far refused to comment on her grandfather's decision. She is currently enjoying a short break in Hawaii.

Paris spent Christmas day with her family in Hawaii. The socialite was spotted shopping with pizza boy lover Alex a few days earlier in California.

Nicky Hilton in her bikini on Christmas in Hawaii. Her legs are weirdly shaped.