Publications
Partners
It has acquired the North American rights for Good Morning, Mr. Mandela, which will be published worldwide on 19 June.
"It's tender, intimate, eye-opening, incredibly moving, and offers a rare portrait of Nelson Mandela and his remarkable life," Viking President Clare Ferraro said in a statement.
The life and beliefs of La Grange were transformed after she started working for Mandela in 1994.
Although she began as a typist, La Grange, 43, went on to become his trusted assistant and worked for Mandela until his death in December at the age of 95.
She accompanied Mandela on trips abroad and was with him when he met world leaders and celebrities.
She will donate a portion of the royalties from the book to the Nelson Mandela Foundation to further his legacy.
Mandela's autobiography, Long Walk to Freedom, was published in 1994.
The book was adapted into the 2013 film of the same name starring British actor Idris Elba as Mandela.
