Helen Gurley Brown, the editor-in-chief of Cosmopolitan Magazine and author of Sex and the Single Girl, has died at 90 at a New York hospital, magazine publisher Hearst says.

Helen Gurley Brown died on Monday in New York after being admitted to hospital.

She edited Cosmopolitan for 32 years after being hired by Hearst to turn around the magazine three years after her 1962 best-selling book.

Helen Gurley Brown, the editor-in-chief of Cosmopolitan Magazine and author of Sex and the Single Girl, has died at 90 at a New York hospital

Under her, the magazine became famous for encouraging women to have sex, regardless of marital status.

Helen Gurley Brown said her aim was to tell readers “how to get everything out of life”.

“Helen was one of the world’s most recognized magazine editors and book authors, and a true pioneer for women in journalism,” Frank Bennack Jr., chief executive of Hearst, wrote in a statement confirming her death.