Sales in Japan of new cars, trucks and buses fell about 3 percent in September from the year before, a source said on Wednesday, underscoring the fragile state of the stimulus-driven recovery in Japanese vehicle demand.

Vehicle registrations, which exclude 660cc minivehicles, as of Sept. 29 were flat from the year-earlier month, totalling around 247,000 units, said the source, who has direct knowledge of the figures.

That follows a 2.3 percent rise in August, which marked the first year-on-year increase in 13 months as the government's tax incentives to stimulate purchases of cleaner cars drove up demand for Toyota Motor Corp's (7203.T) Prius and Honda Motor Co's (7267.T) Insight hybrid models. Sales of minivehicles fell 8.5 percent as of Tuesday to around 119,000 units, the source said, following a 5.1 percent fall in August. The sales figures for this month, including a breakdown by brand, are due to be announced on Thursday.

Toyota registered a 7 percent increase in non-mini vehicles to 111,000 units with one day remaining in the month, the source said. Honda also saw a 7 percent growth, while Nissan Motor Co (7201.T), Mazda Motor Corp (7261.T) and Mitsubishi Motors Corp (7211.T) all saw sales, including 660cc vehicles, drop around 10 percent, the source said. (Reporting by Yoshifumi Takemoto; writing by Chang-Ran Kim)