Forthcoming legislation could limit the average carbon dioxide emissions across the European parc to be less than 120g/km by 2012.
Carmakers will be required to reach 130g/km through engine technology, with the remaining reduction go be achieved through methods such as alternative fuels.
The legislation has caused tension among manufacturers of bigger vehicles, which have claimed it favours those who make small, less polluting ones.
Under the new proposals, manufacturers would be able to team up and meet the requirements between them, thus sharing the burden.
“Where manufacturers form a pool, (they) should be deemed to have met their targets under this regulation, provided that the average emissions of the pool as a whole do not exceed the target emissions for the pool,” the draft said.