Toyota Motor Corp.'s Prius was the best-seller in the April-September period in Japan, becoming the first hybrid to top the sales rankings for the six-month period, industry bodies said Tuesday.

Sales of the gasoline-electric car increased more than threefold from a year earlier to 116,298 units thanks to government tax breaks for purchases of fuel-efficient vehicles, according to data released by the Japan Automobile Dealers Association and the Japan Mini Vehicles Association.

The car is expected to become the top seller for all of fiscal 2009, given that its order backlog is more than 100,000 units, according to industry sources.

The Prius has become more affordable because the minimum price of the new model that came out in May — at ¥2.05 million — is about ¥280,000 less than the sticker price for its predecessor.