The new World Supersport Championship season could open up with not a single example of the 2009 title-winning bike and with less than twenty participants, according to the current entry list.

Yamaha has had a prominent presence in the Supersport category for several years, the R6 proving a popular draw for privateer teams despite it not winning a single title until Cal Crutchlow lifted the trophy last year.

However, the decision by Yamaha to pull its official Supersport squad has filtered down to the remainder of the field, with not a single R6 currently included on the updated provisional entry list less than two weeks before the start of the season.

By comparison, the 2009 World Supersport season opened with six full-time Yamaha competitors, while a number of wild-card riders maintained a high entry-level for much of the season.

As such, the 2010 series will be reduced to three full-time manufacturers, with Honda once again best represented on the grid with eleven entries. Triumph will prepare four Daytona 675s, while Kawasaki has three riders competing on the ZX-6R.

Despite Yamaha's absence, the series is buoyed by having four of last year's top five classified riders returning to fight for the 2010 title.