The Valmadonna Trust Library is back on the market after a bid for the world's finest collection of Hebrew books and manuscripts fell through.
There were reports last December that the collection of 13,000 volumes was sold to an anonymous buyer at Sotheby's in New York in a sealed bid.
But David Redden, vice-chairman of the auction house, said this week that despite meeting the asking price, rumoured to be around $25 million, the private buyer would not agree to the two conditions set by the trust - that the collection remains intact and that it is made available to view by scholars.
The library, collected by 86-year-old London bibliophile Jack Lunzer over seven decades, has been awaiting a buyer since February 2009, but Mr Redden said the trust's demanding conditions meant only a gallery would be in the running and that most would struggle to raise such funds.
"There is a feeling it should go to an institution, but institutions don't have the kind of resources that private buyers do," he said.
Among the collection is a complete set of the Babylonian Talmud by the master 16th century printer Daniel Bomberg.
Mr Redden, who described the library as a "real treasure", said: "It would be wonderful if an institution or individual stepped in. The Valmadonna is eagerly sought by many potential buyers. There have been a number of institutions that have tried to raise money but been unsuccessful."