Around 39 per cent of music fans currently download tracks from illegal sites, compared to 43 per cent last year, the annual digital music survey of 1,500 people found.
However, of those, 72 per cent said they would stop if they were contacted by their internet service provider (ISP).
The research suggests that people are heeding warnings from the Government that it is serious about curbing rampant internet piracy.
Under proposals announced in July, ministers said that illegal downloaders face having their internet access restricted if a voluntary crackdown on piracy is not effective.
Under the voluntary agreement between Britain's six biggest ISPs and the British Phonographic Industry, the internet providers will write to customers identified as illegally downloading material and warn them that their activity is being monitored.
Currently, film and record companies must apply via the courts for the ISP to match the identity of an illegal downloader to the address.
One of the proposals being considered by the Government is to get ISPs to give out that information without a court order.
Russell Hart, the chief executive of Entertainment Media Research, which carried out the study, said:
"It is quite evident that an ISP-led strategy has bite because illegal downloaders are fairly convinced that ISPs are currently monitoring their activities and are more likely to act against them than the courts."
However, illegal downloading showed no signs of slowing down among teenagers.
Some 58 per cent of them said they were not paying to download music, compared to 57 per cent last year and 41 per cent in 2006.Original here