NEW YORK  - A book from Egypt that was written at the dawn of Christianity and is considered one of the oldest books in existence will go up for auction in June in London.

The Crosby-Schoyen Codex - written in Coptic on papyrus around 250-350 AD, and produced in one of the first Christian monasteries - has an estimated sale value of $2.6 million to $3.8 million, according to Christie's.

"It's right at that period, that transitional period, when papyrus scroll starts turning into codex form," said Eugenio Donadoni, Christie's Senior Specialist, Medieval and Renaissance Manuscripts. "So, books as we know them today. And what we have in this book is the earliest known texts of two books of the Bible."

The 104 pages (52 leaves) were written by one scribe over a period of 40 years at a monastery in upper Egypt and are preserved behind plexiglass. The codex contains the first epistle of Peter and the Book of Jonah.

Donadoni attributed its preservation to Egypt's dry climate, adding that only a handful of books from the 3rd and 4th centuries have survived to the present day.

"All the major finds of Christian manuscripts that we had in the 20th century and at the end of the 19th century are all concentrated in Egypt for those very precise climactic conditions," he said.

The codex was discovered in Egypt in the 1950s and acquired by the University of Mississippi, where it remained until 1981. Norwegian manuscript collector Dr. Martin Schoyen acquired it in 1988 and is now auctioning it off with some other highlights of his Shoyen Collection, one of the largest private manuscript collections in the world.

The codex is on view at Christie's New York from April 2 through April 9 and will be auctioned in London on June 11.

(Reporting by Christine Kiernan, Editing by Rosalba O'Brien and Sandra Maler)