Virgin Media and BT have confirmed plans to block access to 21 torrent and file sharing websites believed to be linked to pirated music.
A recent court order instructed UK broadband providers to prevent customers from accessing websites including BeeMPS, Abmp3, TorrentHound, MP3Skull and Torrentz.
They had previously been instructed to block eight other websites - including Pirate Bay - in a bid to combat copyright infringement.
Gareth Mead, a spokesperson for Virgin Media, said that - as "a responsible internet service provider" - his company would obey the court order.
Rival broadband provider BT also confirmed plans to block the offending websites in the coming weeks.
The court order comes after the BPI - the UK's recorded music industry association - took legal action in a bid to protect the interests of rights holders.
"We asked the sites to stop infringing copyright but unfortunately they did not and we were left with little choice but to apply to the court," said BPI Chief Executive Geoff Taylor.