Major carmakers are battling weaker sales in western Europe and to a lesser extent the United States, and are hobbled by high costs for raw materials, high petrol prices, and price wars that have cut their profit margins.

New car sales stagnated in Europe in the first half of the year, slipping by 0.2 percent compared with the same period in 2006 to 8.5 million registrations in 28 countries polled by the Association of European Automobile Manufacturers (ACEA).

Renault and DaimlerChrysler were the hardest hit, though Fiat and Toyota reported higher sales.

Fitch analyst Emmanuel Bulle said the first half was "a little better than expected" but colder weather typically means slower sales later in the year.

Most western European countries, with the exception of Britain and Italy, said the market had softened, but things looked better in eastern Europe, which saw sales climb by 15 percent in the first six months of the year.

Even higher increases were seen in the Baltic states, Poland and Romania.

"The market is being driven by emerging economies, which makes it essential to be there with increased production and more modern products," said Philippe Barrier, an analyst at Societe Generale.

The Frankfurt show, which is held in alternating years with the one in Paris, was therefore placed under the sign of "responsibility," he added.

The IAA has set "sustainable mobility" as its theme, alongside the slogan: "See What Will Move Your Future."

According to Barrier: "We are not chasing a dream, we are going to make a practical purchase."

Automakers, he added, "are not looking for volume at any price, they are taking stock of the market."

Several carmakers will present new models at the auto fair, including Renault with its latest Laguna, Peugeot with the 408 and Opel with the Agila.

Audi is to show a new A4 saloon, and fresh four-wheel-drive offerings include the Volkswagen Tiguan and Ford Kuga.

Questions about responsibility for global warming will be high on the agenda however, with CO2 emissions a hot topic in light of European Commission efforts to cut average levels from new cars sharply from 2012.

In general, automakers have sought to get more performance out of smaller engines, and are also expected to show a range of hybrid and biofuel vehicles as European firms try to catch up with Toyota, the clear leader in hybrid cars.

"Tangible progress has been made, with reduced (petrol) consumption on the order of 10-15 percent," Barrier said.

"The presentations indicate that automakers are ready to make an effort."

Peugeot Citroen has announced a petrol-electricity engine ... for 2010, and will present a 308 HDi hybrid car at this year's show.

It opens to the public on Thursday in the presence of German Chancellor Angela Merkel.

related report
'Clean cars' to shine at International Motor Show
Frankfurt (AFP) Sept 9 - Cleaner cars are set to shine at the Frankfurt Motor Show this week, as pressure builds on automakers to make environmental protection a priority.

Hybrid engines that save energy and run on biofuels or hydrogen, or cars that turn off when stopped to trim consumption and CO2 emissions, are among the responses being offered as more than 1,000 exhibitors from some 40 countries display their wares.

In addition to growing interest in fuel-efficient cars owing to higher petrol prices, the European Commission wants to force automakers to cut CO2 emissions from 2012 to 120 grammes per kilometer from around 160 at present.

"We accept the challenge posed by the global warming debate," said Matthias Wissmann, president of the German Automobile Federation VDA which organises the show.

The Frankfurt Motor Show, in its 62nd year, has even changed its traditional slogan of "Auto Fascination" to "See What Will Move Your Future."

Visitors will fill their own tanks at the "Biofuel Bar" or get in-the-street lessons on how to consume less petrol with the cars they already own.

Among carmakers, German luxury sports car Porsche is to roll out a hybrid version of its Cayenne sports utility vehicle while steadfastly rejecting diesel engines.

Other German exhibitors include DaimlerChrysler, which is to unveil its tiny Smart car equipped with a stop-and-start system that cuts the motor at traffic lights, while its Mercedes brand is to storm the show with 18 "clean cars."

Volkswagen will present six of its own, and Opel has an electric model ready to show.

Among French automakers, Peugeot is pushing the green credentials of its 308 passenger car, which will make its global debut in Frankfurt.

Citroen has prepared the C4 BioFlex, a mid-range hatchback coupe equipped with a biofuel engine.

Environmental considerations are well represented even among audacious "concept cars" such as General Motors' GM Volt, designed with a hybrid engine, or the C5 Airspace convertible by Citroen, which has stop-and-start technology.

Japanese automakers are showing futuristic vehicles of their own, including the small all-wheel-drive Concept-cx from Mitsubishi or the Suzuki Kizashi, which looks like it comes straight out of a comic strip.

It remains to be seen, however, if the public will buy the new technology, since a "clean" car costs 2,000 euros (2,750 dollars) more on average than classic models.

Meanwhile, although four-wheel-drive monsters are to adopt a lower profile at the show, Mercedes will showcase the SLR MacLaren roadster for those who love wheels that roar.

At around 500,000 euros, it is billed as the most expensive new model on exhibition.

Not to be outdone, Ferrari will show the 430 Scuderia inspired by its stable of Formula 1 cars, with seven-time German world champion Michael Schumacher making the presentations.

James Bond fans will admire the latest Aston Martin which appeared in the film "Casino Royale."

And for fans of the iconic communist-era German Trabant, the model maker Herpa is presenting a design to bring the "Trabbi" back.

In all, 260 new cars, including 88 world premieres, have been announced for the show, which is open to the public from September 13-23.