By Jorn Madslien BBC News Online business reporter at the Paris Motor Show

Thirteen leaders of the world's largest car companies have come together for the first time in history to discuss the global environment and traffic safety.

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Following the high-powered gathering ahead of the Paris Motor Show, which opens for the public on Saturday, the powerful executives issued a statement calling for global standards on car safety and environmental regulations.

"International harmonization of technical regulations for motor vehicles will improve safety, protect the environment, and reduce costs for consumers around the world," they said.

"There are areas where we all think it would make sense and make the industry improve faster," said GM chief executive Rick Wagoner

Better filters

The executives called for more action to develop cleaner fuels and to develop alternatives to petrol and diesel.

And they stressed that although diesel remains truly dirty, it should be possible to reduce the releases of particles from diesel engines by improving their filters.

"Current diesel engines are dramatically more efficient than conventional gasoline engines in terms of both fuel economy and carbon dioxide emissions," the executives said.

"Diesel engines also have the potential to meet stringent requirements regarding local emissions."

Lobby group?

Ahead of Friday's low key meeting, several executives refused to answer questions about the meeting.

Sceptics have described the meeting as worrying since they fear the executives arranged their summit to agree on how to lobby for lower environmental and safety standards across the globe.

International standards often involve pulling good performers down rather than raising minimum requirements for countries with poor track records, they point out.

After all, it would be almost unthinkable to demand that China should adopt the same safety standards as those seen in Europe since "this would be seen as intervention in the country's internal affairs", one critic told BBC News Online soon after the summit.

Similarly, given that the US has "stubbornly refused to cut emissions", global standards would merely allow others to "pollute as much as the Americans with their petrol guzzling trucks", she continued.

The meeting was attended by the leaders of the Big Three US car makers Ford, General Motors and Chrysler's parent, DaimlerChrysler, as well as the French car makers PSA Peugeot Citroen and Renault.

The independent car makers BMW and Porsche were also represented, as was Italy's Fiat Auto and Germany's Volkswagen Group.

Also present were the leaders of the Japanese car makers Honda, Mazda, Nissan and Toyota.