The symphonies were offered as part of a 100-hour marathon of the complete Beethoven works presented by BBC Radio 3 in June. The recordings were taken from live BBC Philharmonic performances conducted by Gianandrea Noseda in Manchester.
The most downloaded work was Symphony No. 6 ("Pastoral), which was requested 220,461 times, followed by Symphony No. 7 and Symphony No. 9. In total, there were 1.4 million requests.
Roger Wright, controller of BBC Radio 3, said, "This download experiment began as an added extra to our Beethoven Experience and quickly took on a life of its own."
"The remarkable number of downloads has already sparked a healthy debate bout the place of classical music in the digital world," he added.
The debate includes, according to the London Guardian, those in the recording industry who claim that the BBC was hurting sales of classical recordings and creating unfair competition.
Matthew Cosgrove, director of Warner Classics, told the Guardian, "I would be worried if the BBC repeated the experiment. We would take an extremely dim view if it happened repeatedly."
The BBC is planning a program similar to the Beethoven Experience, but focusing on Bach, later this year.