Almost 75 bikes are expected to contest the 2012 Moto2 and new Moto3 world championships.
Dorna boss Carmelo Ezpeleta has confirmed to MCN that a maximum of 36 bikes will race in the 600cc Moto2 series.
And booming interest in the Moto3 class will see 36 bikes compete in the series, which will feature single-cylinder 250cc four-strokes machines.
Moto3 replaces the current two-stroke 125GP world championship next season and is expected to attract a bumper entry, with Honda and KTM already testing projects for the new series.
Ezpeleta said he expected to have at least four manufacturers involved and he said: “Next year will definitively have 36 bikes in Moto3 and 36 in Moto2. Perhaps some of the Moto2 teams will go to Moto3. But we will not have more than 36 in each class.
"Honda and KTM are already confirmed for Moto3 and Yamaha are speaking of something. Plus there’s an Italian company and also Mahindra."