The complete score of Gustav Mahler's Second Symphony was sold in London for 5.6 million dollars on Tuesday, a record for a musical manuscript, Sotheby's auction house said.

The handwritten 232-page score includes the composer's deletions, alterations and annotations, many of them done in a vivid blue crayon.

The score was owned by US businessman Gilbert Kaplan who became obsessed with the work, known as the "Resurrection Symphony", and dedicated his life to conducting it before his death earlier this year.

The only comparable sales, both sold at Sotheby's, were a manuscript of nine Mozart symphonies for £2.5 million ($3.1 million, 3 million euros) in 1987 and the manuscript of Robert Schumann's Second Symphony for £1.5 million in 1994.

"The result establishes a new auction record for a musical manuscript," Sotheby's said in a statement.

"The work retains the form in which Mahler left it, reflecting and revealing the compositional process for the work," it said, adding that it was the only complete Mahler symphony ever sold at auction.

There were four telephone bidders for the Austrian composer's work but the eventual buyer chose to remain anonymous.

The starting price had been set at £3.5 million.

In the same auction of musical manuscripts, a score said to be autographed by Beethoven, but the authenticity of which had been questioned, failed to sell.

The manuscript of the Allegretto in B Minor for String Quartet had been put up for sale by Sotheby's with a starting price of £150,000.

But Barry Cooper, a musicologist and Beethoven scholar, told BBC radio there were inconsistencies in how the notes were written.

Some notes were "slightly ambiguous" but for others it was "clear" that "copiers simply miscopied a note in a way that Beethoven certainly wouldn't," he said.

"The curves in this copy are much more curved and elegant than any curves in Beethoven's manuscript," he said.

Simon Maguire, head of musical manuscripts at Sotheby's, said the work had been authenticated by two Beethoven experts.

"If we got something wrong, we would have to pay out," he said.

'Bolt of lightning'

Kaplan became infatuated with Mahler's symphony after seeing it performed at New York's Carnegie Hall in 1965.

"Zeus threw the bolt of lightning. I walked out of that hall a different person," Kaplan said.

The economist then trained with the world's top conductors to be able to perform the piece and went on to do so more than 100 times around the globe.

The monumental symphony premiered in Berlin in 1895 and is performed with a 90-piece orchestra, soprano and alto soloists, chorus and organ.

"This was the first major work that saw the composer confront the universal themes of life and death, which were so characteristic of his oeuvre," Sotheby's said.

The manuscript was given by Alma Mahler, the composer's widow, to the conductor Willem Mengelberg, a friend of Mahler's, in 1920.

Kaplan bought it from the conductor's estate in 1984.