TOKYO (AP) — A U.S. hedge fund has proposed that Sony Corp. sell up to 20 percent of its entertainment business and use the money to strengthen its ailing electronics unit.

In a May 14 letter to Sony President Kazuo Hirai, first published in The New York Times, hedge fund Third Point suggested Sony take 15 percent to 20 percent of the entertainment unit public.

Third Point CEO Daniel Loeb said that would allow the Japanese maker of PlayStation game machines to raise cash to strengthen its battered electronics operations.

Sony replied in a statement Tuesday that its entertainment business, which includes movies and music, is not for sale.

It said is trying to strengthen both its electronics and entertainment businesses.

Sony's electronics business has been ailing for years.