Penguin has bought the rights to Nicole and Natalie Appleton's autobiography.
The publisher is thought to have paid between £750,000 and £1 million for the All Saints sisters' story, on the basis of a 75-page synopsis.
The publishing director who bought the book said, "This is the frankest proposal for an autobiography I have ever read." He added that it is also a book about sisters who are "dissimilar in every way but intrinsically connected".
The girls have vowed to tell all about the recent split in All Saints and promised to spill the beans on their past and present boyfriends including Robbie Williams and Liam Gallagher.
The book is due out in October. All Saints have sold more than 10 million albums worldwide.
