In the letter dated December 12, 1914, Einstein criticises his estranged wife Mileva Maric for not sending on his greetings to their sons Hans Albert and Eduard.
It reads: "Greetings from me to the children do not seem to be passed on, otherwise they would have sent greetings to me."
It also reveals how Einstein - famous for his theory of relativity - told Maric how much he would pay in maintenance for his kids.
"The letter shows the domestic side of Einstein's life, often overlooked because of his theories," The Sun quoted spokesman as saying.
The letter is expected to fetch 2,000 pounds. (ANI)