Loeb won nine stages of the Rally of Catalunya

Citroen claimed three of the first four places in the season's penultimate race, meaning they cannot be caught by second-placed Peugeot.

Belgian Francois Duval was second and Spain's Xavier Pons fourth, while Finn Mikko Hirvonen, in a Ford, was third.

The highest placed Peugeot driver was France's Nicolas Bernardi in sixth.

Loeb won just one stage on the final morning but with a comfortable advantage courtesy of two dominant days, he was never threatened.

Citroen only needed six points to be sure of the manufacturers' title while rivals Peugeot needed a one-two to keep the fight alive going into the final round in Australia.

But Marcus Gronholm's retirement overnight ended any slim hopes Peugeot had.

The Finn was running third but a leaking radiator caused a blown engine after Saturday's last stage and he was unable to start Sunday's action.

That lifted ex-works Subaru driver Hirvonen, now driving a private Ford, into a superb third place.

A high attrition rate among the top drivers helped some lesser lights break into the upper echelon of the leaderboard, with independent Citroen driver Pons earning a stunning fourth.