The deal covers films found via the bittorrent.com website run by Bram Cohen - creator of the download system.

It means bittorrent.com must remove any links to pirated films made by seven Hollywood movie studios.

As it only covers the bittorrent.com website it is unclear what overall effect it will have on net piracy.

Link list

What is not known is how many of the 45 million users of BitTorrent search for files to download via the BitTorrent.com site. Many other websites let people search for so-called "torrents" or simply list the most popular ones for people to download and these sites could be unaffected by the deal.

The deal between the Motion Picture Association of America (MPAA) and BitTorrent is the latest in a long line of moves to limit the illegal sharing of films via the net.

BitTorrent has become a widely used way for many to get hold of very large video files as the technology is very efficient at splitting up and sharing data.

Use of the system has proved to be a thorn in the side of the MPAA as it can make it hard to work out who is behind illegal movie sharing.

Under the deal Mr Cohen must stop people being able to find pirated films when they search via the bittorrent.com website. He has also agreed to speed up the issuing of notices telling people to stop illegal sharing.

"BitTorrent Inc. discourages the use of its technology for distributing films without a license to do so," said Mr Cohen in a statement.

Mr Cohen has reportedly raised $8.75m in financing to turn the BitTorrent technology and the associated website into a commercial download service. The deal is widely seen as giving that nascent service official approval.