Porsche introduced the revamped Panamera coupe at the Shanghai auto show where it sought to outshine Maserati's new Ghibli to win over China's growing ranks of luxury-car buyers.

BMW's X4 SUV, Mercedes' GLA compact SUV and a sedan version of the Audi A3 also had world premieres at China's biggest auto show of 2013. The unprecedented high-end car push underscores the country's emergence as the segment's key market for expansion.

"There's still a lot of growth potential in China," Audi CEO Rupert Stadler told reporters in Shanghai. "The premium segment accounts for about 9 percent of the total market and that share could grow to between 12 percent and 15 percent."

With Europe's car market sliding to a 20-year low on weakening demand in Germany, the region's luxury-car makers are focusing on China's wealthy. The push is prompting a shift to SUVs and sedans, which are more popular there than European hatchbacks and wagons.

To tap China's growth, Porsche will offer an extended version of the Panamera four-door coupe, which is 15 centimeters longer than the standard model.

The variant, which is priced from 132,662 euros (1 million yuan) in Germany, is geared chiefly at the Chinese market, where many luxury-car buyers have chauffeurs, making rear legroom a key factor.

The second generation of the Panamera will go on sale in July, starting at 81,849 euros. The model also marks the introduction of a new V-6 biturbo engine, which will replace a larger V-8 engine as manufacturers look to improve fuel efficiency. The engine boosts fuel economy as much as 18 percent while still adding 20 horsepower.

"We remain carefully optimistic," Porsche sales chief Bernhard Maier said. With the new Panamera and recently overhauled 911 sports car, Porsche's "better prepared than ever before" to cope with market swings.

Fiat S.p.A.'s elite Maserati brand is shifting down market with the new Ghibli. Its first-ever mid-sized sedan, which is equipped with an engine with at least 330 hp, will vie with top-end versions of the Mercedes E-Class and BMW 5-Series.

The new entry-level Maserati, which can accelerate to 100 kph in as little as 4.8 seconds, is a key part of Fiat's plan to stem losses in Europe, which amounted to more than 700 million euros last year.

Fiat CEO Sergio Marchionne is targeting Maserati sales of 50,000 cars in 2015, up from 6,000 units last year.Fiat's European turnaround plan calls for exporting 16 new, Italian-made upscale cars worldwide, including an Alfa Romeo SUV, a small Jeep and six Maserati models.

The Ghibli, which is due to start at more than 50,000 euros, will be built at the Grugliasco facility in Turin, Italy, alongside the Quattroporte, Maserati's flagship.

"It's sad to say, but the world turned upside down," Maserati chief Harald Wester said in Shanghai. He expects sales to surge to 20,000 vehicles this year, with half of that volume coming from the Ghibli.

Daimler, which has struggled to grow as fast competitors in China, is betting the GLA, the fourth in a new line of front-wheel-drive vehicles, will help Mercedes gain market share by appealing to drivers other than older men.

With the new SUV, "we want to gain more younger customers, more female customers and ones that are outdoorsy and are very active in their lifestyle," Daimler CEO Dieter Zetsche said.

In addition to the Porsche Panamera, Volkswagen flexed its muscle with the Bugatti Veyron 16.4 Grand Sport Vitesse in Shanghai, which according to VW is the world's fastest series-made roadster after reaching a top speed of 409 kph last week.

The car, which is powered by a 1,200-horsepower engine, was driven on VW's testing center in Ehra-Lessien in northern Germany by 29-year-old Chinese entrepreneur and race-car aficionado Anthony Liu.

New models might help luxury-car makers cope with Europe's sales slump this year. Demand for new vehicles in Europe is expected to decline for the sixth consecutive year, while China's sales growth is easing to less than 10 percent annually.

"Growth rates in China are normalizing," BMW sales chief Ian Robertson said in Shanghai, where he presented the all-new X4. "The market is maturing." Italian automaker Maserati launched its Quattroporte flagship sports sedan in China -- part of the company's goal of selling 12,000 worldwide this year.

The Quattroporte will carry a price tag of 2.7 million yuan, or $434,000. The company has not announced a sales goal for the model; overall, the brand expects to sell 1,000 to 1,500 units in China this year.

The Quattroporte is powered by a 3.8 liter V-8 engine that generates 530 hp.To boost sales, the Fiat subsidiary will have 35 dealerships in China by the end of the year, up from 25 now.