"Our customers are asking for it. We have been monitoring pre-orders and decided we had enough" to put the book on retail shelves, company spokeswoman Mary Ellen Keating said.

If I Did It, in which the former US football star offers a hypothetical account of his ex-wife's murder, has caused a firestorm of controversy since it was revealed last November that Simpson worked with a ghostwriter to author it.

Simpson was acquitted of murder charges in 1995, but was later found liable for the killings in a civil trial and ordered to pay $US33.5 million ($41 million) in damages to the victims' families.

The original publisher scrapped plans for If I Did It after public outrage, and the family of Ronald Goldman, who was killed with Simpson's former wife Nicole Brown Simpson in 1994, eventually won rights to the book in a court battle.

Last month, New York-based Beaufort Books partnered with the Goldman family to publish If I Did It because the publisher believes it will be seen "as a confession by many who will read it," according to a statement from Beaufort.

The book is set for a September 14 release, and 150,000 copies will be printed, up from a previously planned 125,000 copies, according to a Beaufort spokeswoman.

Ms Keating said Barnes and Noble originally believed demand would not be high enough to put the book in stores. But online pre-orders have risen more than expected and the book has been on the top 100 list at barnesandnoble.com. © 2007 Australian Broadcasting Corporation