-- France's Renault SA stole the spotlight at the Frankfurt Motor Show, unveiling four electric cars and pledging to bring them to market at affordable prices within three years.

Most automakers displayed concept or production vehicles demonstrating advances in electric car technology, which has emerged as a dominant theme of the show. Volkswagen revealed an e-Up electric show car along with new sporty cars loaded with horsepower, and PSA Peugeot Citroen showed an electric car based on Mitsubishi Motors Corp.'s i-MiEV, already on sale in Japan.

"I think it's going to come quicker than people anticipate," Nick Reilly, General Motors Co.'s executive vice president for international operations, said of the electrification of cars.

GM's German carmaker Adam Opel GmbH displayed an Ampera model that uses the extended range electric vehicle technology seen in the Chevrolet Volt.

Shared technology and common underpinnings were another show theme: Ford Motor Co. displayed a C-Max car built on architecture that will be seen in nine other Ford models, including the next Focus. Opel unveiled a snappy Astra car whose architecture will be seen on all GM compacts.

Unlike past downturns, which have led executives to put off spending on environmental improvements, strict regulations coming into force in most regions and shifting consumer tastes have encouraged the development of alternative technologies.

Renault, along with its Japanese affiliate Nissan Motor Co., has outlined plans for the most aggressive rollout of electric cars. Carlos Ghosn, chief executive of both Renault and Nissan, said Renault's electric cars would be priced so that the cost of ownership would be similar to or less than the cost of owning a diesel-powered car in Europe today. Diesels cost slightly more than gas-powered cars, but provide much better fuel economy.

"What's at stake today is not getting 20 or 30 percent fuel economy improvements. It's to have cars with no emissions at all," Ghosn said.

Renault pulled the wraps off a Twizy ZE, a tiny city car that resembles the Nissan Pivo electric vehicle concept; two sedans, the Zoe ZE and the full-size Fluence ZE; and an electric version of the boxy Kangoo. "ZE" stands for "zero emission."

Ghosn said he expects electric vehicles to account for at least 10 percent of industry sales by 2020.

Fiat SpA's Ferrari sports-car maker unveiled a 458 Italia coupe powered by a 4.5-liter V-8 direct injection gas engine that delivers 570 horsepower. It will go on sale in Europe by the end of the year for about $255,400. The car is likely to roll into Ferrari's U.S. showrooms next year.

British luxury car maker Bentley, now owned by Germany's Volkswagen, introduced its massive new flagship sedan, the Mulsanne. Replacing the discontinued Arnage, the Mulsanne will sell for about $300,000 in the United States. Its hood conceals a twin-turbocharged, 512-horsepower, 6.75 liter V-8.

BMW is expanding the lineup of its Mini brand by two models unveiled at the show, a coupe and roadster, to six in all. Mini plans to expand its U.S. dealerships by 20 percent over the next 15 months, putting the Mini brand in more than 100 dealerships for the first time. The United States is Mini's biggest market.

BMW also unveiled a diesel-electric concept sports car, the Vision EfficientDynamics, with gull-wing doors. BMW says it can run for about 30 miles on battery power alone.