Paris bookseller Christophe Champion, at bookshop Faustroll, brought the documents to market this weekend, to coincide with the International Rare Book & Fine Art Fair 2020 (Salon International du Livre Rare & de l'Objet d'Art 2020) taking place at the Grand Palais from September 17-20.
The bundle is being sold for €60,000.
The letters are thought to be between Mr Saint-Exupéry - aviator and famous author - and a “mystery” American woman, named Jane Lawton, a woman who worked for the Walt Disney company, but about whom not much more is known.
The letters make reference to “an angel feather”, and talk of “memories of a gramophone playing sad songs, honey-coloured whisky, and of perhaps-shared friendship...a memory I have kept”.
The "angel feather" may have referred to a golden feather that Mr Saint-Exupéry kept after his first evening with Jane, which may have come from her hat or outfit, said Mr Champion.
The two are said to have met in 1938 or 1939 in New York, while the writer was in the United States, and his marriage to wife Consuelo was said to be “up and down”. The author dedicated his award-winning book, Terre des Hommes, to a “Jane Lawton...with the certainty of seeing her again, because as mankind’s Earth is round, we cannot lose ourselves too far”.
Later letters suggest that Mr Saint-Exupéry later visited New York again after the publication of his book Pilote de Guerre, and a telegram from 1940 reads: “...If I told you that I was not only coming [to New York] for my book, you will laugh…but it’s true”.
Jane Lawton, dite "Plume d'ange" par Antoine de Saint-Exupéry. Personnage jusqu'ici inconnu, mais qui compta dans les dernières années de l'écrivain (photo: librairie Faustroll) https://t.co/FKSfvPbA2k #AFP pic.twitter.com/zAyoVSdvGs— Hugues Honoré (@hhonore) September 18, 2020
The author is later thought to have given Ms Lawton a rare and specially-printed original edition of one of his books, with a double-page illustration spread by the artist - and Mr Saint-Exupéry’s good friend - Bernard Lamotte.
Ms Lawton would later write a three-page synopsis of Mr Saint-Exupéry’s much-loved children’s book Le Petit Prince - which he largely wrote in New York - one year after the pilot’s disappearance, perhaps as a possible film adaptation proposal of his famous book.
Bookseller Mr Champion told newspaper Le Figaro: “It seems to be an intimate relationship, which appears to intensify with each letter, and when he keeps a copy of Pilote de Guerre on precious paper with a printed dedication, that is a sign. A writer would keep such things for very close friends. That is a considered gesture.”
The sale of the letters comes 10 years after auction house Christie’s sold a long letter by Mr Saint-Exupéry, apparently to Ms Lawton, although her name does not appear. The letter read: “Many things touch me about you.”
Mr Saint-Exupéry disappeared without a trace during a flight near Marseille in 1944, and later discoveries of parts of his plane and belongings suggest he died after his plane crashed into the sea.