Toyota Motor Corp. will reveal the first redesign of the Prius in almost seven years in Las Vegas next month, wagering that new looks can revive demand for its top- selling hybrid.

The 2016 Prius will be shown to media on Sept. 8, spokesman Ryo Sakai said by phone. He declined to say when the company will start production or sales of the updated model.

Toyota's last revamp in 2009 catapulted Prius into the mainstream as the first hybrid to cross 500,000 units in its first full year on the market. By comparison, Tesla Motors Inc. targets that many deliveries for its whole lineup in 2020.

Both the Prius and Toyota are now at a turning point. The lack of major updates to the model has crimped demand in Japan, and cheaper gasoline is an added headwind in the U.S. The company also has ceded some green-car buyers to fully-electric autos from Tesla, Nissan Motor Co. and BMW AG.

"Despite all this rising competition and more choice for consumers, Prius is holding its own," Ashvin Chotai, managing director of researcher Intelligence Automotive Asia, said by phone. "Any model normally gets a first-year boost to sales, and this one probably will be more like a couple of years."

Sales of Prius in Japan, its biggest market, plunged 31 percent this year through June. Deliveries in the U.S. dropped 14 percent during the same period.

Toyota will show the revamped Prius as it takes U.S. orders for the hydrogen-powered Mirai sedan, which it sees as the automotive technology of the future. The company's first fuel cell vehicle leapfrogs the gasoline-electric Prius by fully eliminating tailpipe emissions.

Prius will be the first model to implement Toyota's company-wide effort to cut development costs by 20 percent through sharing platforms, parts and powertrains.