Grosse Fuge dates from the year before Beethoven died

An anonymous buyer purchased the score of Grosse Fuge in B flat, which features the composer's changes.

London auctioneers Sotheby's had expected the manuscript to fetch up to �1.5m but a spokeswoman said it had still achieved "an excellent price".

It had not been seen in public since an auction in 1890, before it was found by a librarian at a US religious school.

The buyer at the 1890 Berlin auction is believed to have been an industrialist from Ohio who took the manuscript to the US.

The sale falls short of the record for a Beethoven score, achieved by a working manuscript for his Ninth Symphony, which sold for more than �2.1m at auction in 2003.

Chance find

Sotheby's claimed the discovery would prompt a reassessment of the composer's works, as it provides insight into his working methods.

It is not known how the manuscript ended up at the seminary

The German composer wrote Grosse Fuge in 1826 while contending with deafness.

The score, which contains multiple deletions and corrections, was found by librarian Heather Carbo at the Palmer Theological Seminary in Philadelphia in July.

Ms Carbo was conducting an inventory of the seminary's archives when she came across the manuscript in a basement cabinet.