BitTorrent is widely used to trade material like TV shows and movies. It makes the sharing of material easy by breaking a file up into fragments and then distributing them.
Chan was released on bail of 5,000 Hong Kong dollars (US$641) pending a sentencing hearing scheduled for 7 November.
He had been charged in April for uploading three Hollywood blockbusters to the net - Daredevil, Red Planet and Miss Congeniality.
The Hong Kong government said the case was its first successful action against peer-to-peer file sharing. The maximum penalty is four years' jail and a hefty fine.
"This ruling means a lot," said Hong Kong Commerce Secretary John Tsang, explaining that it would deter other possible file-sharers.
The Hong Kong customs department said that since the arrest illegal file-sharing had fallen by 80%.
The movie industry started targeting the operators of BitTorrent networks themselves last December.
It filed numerous lawsuits against BitTorrent server sites which linked to copyrighted material in order to undermine the ability to swap content.
The action resulted in the closure of some high-profile BitTorrent sites.
In May, US Federal authorities succeeded in closing a network that was distributing pirated copies of Star Wars: Episode III - Revenge of the Sith before the film opened in cinemas.