Brussels - French car manufacturers are the closest to hitting proposed European Union targets for reducing their carbon dioxide (CO2) emissions, while Japanese makers are the furthest away, a study by a Brussels pressure group released Tuesday said.

But neither group managed to make substantial cuts in their new cars' emissions in 2007, leaving it open to question whether they would hit their targets, the study commissioned by Brussels-based environmental group Transport and Environment (T&E) said.

Under laws proposed by the EU's executive, the European Commission, and currently under debate, every car manufacturer which sells large numbers of vehicles in Europe should be given a target for the average amount of CO2 its new cars emit from 2012.

The proposed targets are calculated according to the average weight of car each firm sells, Fiat and Suzuki having an estimated target of 122 grams per kilometre (g/km), and luxury manufacturers BMW and Daimler aiming for 137 g/km based on current car weights.

According to T&E's study, based on official EU data, the Peugeot- Citroen group is closest to its target, needing to reduce average new car emissions by 10 per cent in the next five years. Renault faces a 13-per-cent cut, Fiat needs to cut by 14 per cent and Toyota needs to cut by 15 per cent.

At the other end of the spectrum, Suzuki faces making cuts of a hefty 25 per cent in its average car emissions, Daimler and Mazda will have to make 24-per-cent cuts and Nissan will have to cut by 22 per cent, the study said.

"It is striking that three of the bottom four carmakers are Japanese ... All three did not close the gap sufficiently in 2007 and will have to speed up their efforts," it said.

Mazda cut its average emissions by 1.4 per cent in 2007, Suzuki cut by just 0.8 per cent and Honda actually boosted them by 1.1 per cent - leaving the trio requiring a major effort if they are to hit EU targets.

While French carmakers are closer to their targets, they are making slow progress: Peugeot-Citroen cut emissions by 0.9 per cent in 2007, while Renault managed just 0.5 per cent, meaning that both groups will have to step up their efforts in order to hit the target.

Germany's BMW made the largest cut of any major manufacturer, reducing emissions by 7.3 per cent, but its current target leaves it facing a 19-per-cent cut before 2012. Daimler and Volkswagen are as far away from their targets and made smaller cuts in 2007. (dpa)