After the post-production was rushed for the world premiere in Venice, the sales company will work with the film-makers after Toronto to recut the film.
Gordon Spragg, Celluloid Dreams' director of marketing and publicity, said: 'It was really down to the wire with the film still editing two weeks before Venice - that's extremely tight. There were a couple of problems, including some technical problems with the sound mix. Also, we just think the film could be tightened. The film is there, and I don't think there will be any reshoots.'
A new cut could be ready in time for AFM in November.
No deals for the film have been done yet and in an email to potential buyers, Celluloid wrote: 'we urge you to wait for this new cut and to abstain from watching the film in its unfinished form in Toronto.'
But Spragg noted that of course if buyers are interested in the film in Toronto, Celluloid will start discussions.
The version for Venice and Toronto runs 118 mins. The TIFF screenings start Sunday.
Celluloid Dreams said it didn't seriously consider pulling the film from Toronto because of the new plans to recut it, 'because we have a really good relationship with the festival, we wouldn't want to pull any film.'
Hong Kong-based Yu Lik-wai shot his third feature in Sao Paulo's Liberdade district, seen as a futuristic multi-ethnic neighorhood, as a Chinese outlaw faces off with his adopted son.
Yu's XStream Pics label produced alongside Gullane, with Japan's Bitters End, Hong Kong's Sundream Motion Pictures and Paris Filmes taking co-producer credits. Other backers are ARTE France, Media Factory, Ozone Network, and TeleImage.
The cast features Joe Odagiri, Anthony Wong, Huang Yi, Tainá Müller, Jeff Chen, Phellipe Haagensen, Antônio Petrin, Milhem Cortaz, Alexandre Borges and Cláudio Jaborandy.
Reviewing the film for Screen in Venice, Lee Marshall wrote: 'Even the most attentive viewer will likely be baffled by Plastic City's elliptical, not to say half-baked, narrative.'