Aprilia has officially confirmed that it has abandoned its Moto2 project.
A statement by the Piaggio Group - owners of Aprilia - confirmed that the famous Italian constructor will not have a factory presence in the new Moto2 class, which replaces the 250cc World Championship from next season, or provide machinery for private teams to race with.
The main reason given for the withdraw is the required use of a Honda-built engine, but since that single-engine rule was announced on May 5 it remains a mystery as to why Aprilia has waited so long - its Moto2 chassis is said to be 'almost finished' - before reversing its decision to compete.
"It would be useless and harmful to the image of a large Italian and European motorcycle manufacturer, which has won 43 world titles in road racing and off road competition, to take part in a competition which relies on engine technology by a rival constructor," said the (translated) statement.
The Aprilia withdraw leaves several leading teams, including Mapfre Aspar and Speedup Aprilia, to either find a new Moto2 chassis manufacturer or try to acquire what has so far been achieved by the Aprilia design team and continue the project themselves.
Jorge Martinez 'Aspar', who had made clear it is very late for Aprilia to have such a change of heart, had hoped to give his riders Julian Simon and Mike di Meglio their debut on the Aprilia chassis at the forthcoming Valencia Moto2 test, from December 9-10.
It is thought that Aprilia will now channel its planned Moto2 resources into an expansion of its WSBK presence, from one to two teams, and perhaps even begin planning for a future MotoGP return, should rumoured rule changes allow production-based engines in the future.
But such long-term planning seems at odds with Aprilia's sudden about-turn over Moto2, which has prompted questions about the company's leadership.
The only 2010 grand prix class to feature the Piaggio brands - Aprilia, Gilera and Derbi - will now be 125cc.
Aprilia narrowly lost out on the final 250cc World Championship to Honda, but won the 125cc title with Aspar and Simon.