The makers of Steamboy, the $20m animated feature by Katsuhiro Otomo, have delayed the film's release date from October to sometime in 2004.
Announced at a press conference on June 19, this decision leaves a huge hole in distributor Toho's autumn schedule.
The film, Otomo's first full-length theatrical feature in fifteen years, since his international hit Akira, has been in production since 1997. Costs are expected to total $20m (Y2.4bn) - the most ever for a Japanese animation, including the 2001 mega-hit Spirited Away.
Representing the film's producers, Bandai Visual president and CEO Kazumi Kawashiro told reporters that they "truly regretted" the decision, which was motivated by difficulties completing the film's climatic scenes. "The quality and quantity of work required were more than we had anticipated," he explained.
The finished film is expected to require nearly 180,000 cels for its two-hour running time - again a record for a Japanese animation.
A retro science fiction epic set in Victorian England, Steamboy tells the story of a young inventor who receives a mysterious "steam ball" from his American grandfather - and discovers its devastating power.
A manga artist and animator, whose 1988 film Akira stimulated worldwide interest in Japanese animation, Otomo has retreated from the front lines of animation in recent years. His return in Steamboy has been highly anticipated, particularly by Bandai and other investors, who are counting on strong overseas sales to recoup.