Volkswagen's Audi arm has bought Italian motorcycle firm Ducati for an undisclosed sum.

The 20-member supervisory board of Europe's largest carmaker agreed to add a 12th brand to its portfolio.

The purchase will be completed when approval from the necessary regulators is received.

Ducati has won 13 rider's Superbike World Championships since 1988, and the deal means Audi's rivalry with BMW will now include superbikes.

However, one expert has questioned the wisdom of the purchase.

"I can't think of a concrete reason for Audi to warrant a business case for buying Ducati," said Stefan Bratzel, director of the Center of Automotive, at the University of Applied Sciences in Bergisch-Gladbach.

"Ducati does not enhance Audi's business model in any way, it is just a trophy in the wall cabinet."

Ducati makes about 40,000 bikes a year across its range of cruiser, supermoto, adventure, naked, and superbikes.

Source :bbc.co.uk