The Hong Kong-based Tom Group is negotiating to acquire a 20 per cent interest in Huayi Brothers Media Group, the biggest private filmmaker on the mainland, as the country opens up its movie industry to foreign investment.

Huayi, which made this year's award-winning comedy Cellphone, is planning an overseas listing in three years, according to industry sources.

The sources say Tom would have to pay hundreds of millions of yuan for the stake, but no framework agreement has been signed yet.

The move follows United States giant Warner Brothers' announcement last month that it was setting up the mainland's first film production joint venture with state-owned China Film Group and privately run Hengdian Group.

Main board-listed Tom declined to comment on the deal.

The State Administration of Radio, Film and Television recently relaxed its rules to allow non-mainland companies to take part in film and television production.

However, up to now, foreign players have been wary of investing in the lucrative market because of rampant piracy in films, software and music.