Beethoven finished his symphony in 1823
Described by auction house Sotheby's as one of the most important documents of the German composer, it had been expected to fetch up to £200,000.
The single-sheet manuscript was sold to an anonymous telephone bidder at the London auction house, a record for any Beethoven document.
It was put up for sale by an unnamed charitable foundation which supports music education.
The work shows Beethoven's first attempts at the opening of the epic piece, completed in 1823.
The manuscript has been dated to 1818, which was around the same time as he was commissioned by London's Royal Philharmonic Society to write a symphony.
Dr Stephen Roe, head of the manuscripts department at Sotheby's, called the price "absolutely extraordinary".
"That is an incredible price and it is about 10 times more than any Beethoven sketch leaf has ever gone for," he said.
"We knew that it was going to do well but we had no idea that it was going to do that well.
"There were four or five bidders to start with and then that got whittled down to two and then there was a duel which lasted for about five minutes."
First ideas
The much-celebrated work was first performed in Vienna and has been credited with influencing other great composers including Schubert, Brahms and Wagner.
Beethoven 19th Century scholar Gustav Nottebohm described the manuscript as the "very first sketch for the Ninth Symphony" and is also inscribed with his initials.
"We have sold a few things for over a million pounds before in terms of music but not for a single leaf of manuscript," added Dr Roe.
"People have obviously looked at that, and quite rightly so, as Beethoven's first ideas for the Symphony and regarded it as an incredible thing."
The prestigious lot is part of musical manuscripts sale, which also includes a complete score of Mendelssohn's famous composition, the Hebrides Overture, also known as Fingal's Cave.