Sotheby's auction house said the eggs and 180 other Fabergé pieces collected by the late Malcolm Forbes would be offered in New York on April 20 and 21 and could fetch between $90m and $120m.
The eggs were first commissioned by Tsar Alexander III from the House of Fabergé master jewellers in 1885 as Easter gifts for his wife, Tsarina Maria Feodorovna. The tradition continued for 30 years in the Romanov imperial family.
The eggs, which alone are expected to fetch between $65m and $95m (£35m to £52m), will be displayed at Sotheby's from April 12.
There are 50 Imperial Easter Eggs scattered around the world, including the nine owned by the Forbes family. There are 10 in Moscow's Kremlin Collection, the Virginia Museum of Fine Arts in the United States has five, and the Queen owns three.
The others are in the US, Switzerland and Monaco; eight are unaccounted for.
Only seven have been auctioned in the past 65 years, according to Sotheby's.
"The sale of any one of these eggs would be an event. The sale of nine is unprecedented," David Redden, its vice-chairman, said yesterday.
They have been displayed at Forbes Galleries and shows worldwide since the death of Malcolm Forbes 14 years ago.
According to Sotheby's Fabergé expert, Gerard Hill, Forbes's ambition was to surpass the Kremlin's collection.
The Soviet Union began selling the eggs in the 1930s.
The family said in a statement that Malcolm Forbes had left it to his children to decide whether or not to sell one of the collections, but he hoped that it would be auctioned.
"The family has now decided it is time to make this unique treasure trove available to other collectors so they may have the thrill of owning a rare and exquisite work of Fabergé."
