The two-day sale of around 700 lots will comprise artworks and objects from both the Munich gallery, Bernheimer Old Masters, and family's country seat, Burg Marquartstein, a Medieval castle between Munich and Salzburg which will also be sold through Sotheby's International Realty.
Included are items from the attics to the Lapidarium, furniture and decorations, 19th century paintings, sculpture and Old Master paintings, as well as works of art, porcelain, books and manuscripts.
Mr Bernheimer represents the fourth generation of one of Europe's major art-dealing families, which was founded in 1864 in Munich, and has led the business since 1977. He now feels it is time to hand over to the next generation, his daughters, who will take the business forward in new directions.
However, he will continue to deal in Old Master paintings as chairman of Colnaghi in London, which the Bernheimers acquired in 2002.
Speaking to ATG, Mr Bernheimer clarified what this would mean for the business: "There will be no Old Master paintings any more in Munich. Munich will continue with the emphasis on Modern and Contemporary, because of my daughters. And my personal activities in the field of Old Masters will be concentrated to London, to Colnaghi."
He added: "Bernheimer and Colnaghi were never really united; I always kept them as separate entities. And as Munich will be dealing in Modern and Contemporary and Colnaghi will definitely continue with Old Master paintings, it will become even more evident that these are two different companies.
"In Maastricht for instance, or in London at Frieze Masters, there will be no Old Master paintings by Bernheimer. At Frieze Masters there will be a cooperation between my daughter Blanca with her company Bernheimer Fine Art Photography and Colnaghi, and in Maastricht it will be just Colnaghi."
The family's main residence is in Munich. On the decision to sell Burg Marquartstein, their country residence, Mr Bernheimer said: "Unfortunately we never spent enough time in Marquartstein, and we never could make up our mind to take it up as our main seat. So we used Marquartstein for weekends and for holidays, not enough. And, as we said before, none of our daughters would have taken over, they all live a different lifestyle, and most of them live either in Switzerland or in Berlin. I might indeed spend more time in London."