Author Salman Rushdie, shown in London Oct. 8, is at work on a memoir of his time in hiding under threat of death. (Andrew Winning/Reuters)

Booker Prize-winning writer Salman Rushdie is at work on a memoir about the decade he spent in hiding because of a fatwa calling for his death.

Rushdie told the Reuters news agency in London that he has already written 100 pages for the new book, which could be published as early as 2011.

The fatwa issued against him by Iranian leader Ayatollah Khomeini in 1989 called on Muslims to execute him following the publication of his novel The Satanic Verses, seen as blasphemous because of its depiction of the Prophet.

Rushdie spent the next 10 years under the round-the-clock protection of Scotland Yard's Special Branch. In 1998, the Iranian leadership modified its position on Rushdie, in an attempt to mend ties with Britain.

Rushdie, a British citizen, has spoken frequently about the experience and the anger he feels at arbitrary regimes that try to suppress freedom of speech. However, he said, it is only recently that he felt ready to write about the experience.

"I'm not getting churned up and upset, I'm just writing it and I'm feeling quite pleased to be writing it," he told Reuters.

When the memoir will be ready depends in part on the other project the Indian-born author has on the go — adapting his Midnight's Children for the screen. Canada's Deepa Mehta is to direct a movie based on the book, which won both the Booker Prize and the Best of Booker Prize in which readers chose their favourite novel from among winners of the prestigious award.

Rushdie, 63, is on a book tour in support of his young adult book, Luka and the Fire of Life. He has written 10 novels and four works of nonfiction.