Toyota Motor Corp.'s Prius, a niche oddity when it went on sale 15 years ago, jumped to the world's third best-selling car line in the first quarter as U.S. demand and incentives in Japan turned the hybrid into a mainstream hit.

Prius sales more than doubled as Toyota extended the name to a four-model "family" of vehicles at the same time that rebates and tax breaks in Japan are saving buyers the equivalent of $2,500 or more.

In the quarter, sales soared to 247,230, trailing only Toyota's Corolla, at 300,800, and Ford Motor Co.'s 277,000 Focus sales.

The Prius surge, after two years of recalls and production disruptions, propelled Toyota back into the global sales lead for the first three months of the year.

The hybrid line also gives the Toyota brand three of the top 10 models in the United Status so far this year, including its mid-sized Camry.

"It proves Prius wasn't a fluke, that there's a long-term market for hybrids," said Eric Noble, president of the Car Lab, an automotive consultancy in Orange, Calif.