The decision is not yet official, but according to e-magazine GPWeek.com
"In response to a deadline set by Dorna, the axe finally fell on the on-again/off-again Suzuki MotoGP team last Friday, with the factory decision to pull out of the premier-class."
adds that an email to team members from Paul Denning states that Suzuki hopes to return to MotoGP in 2014.
Alvaro Bautista, Suzuki's only full time rider this year, has already signed for Gresini Honda, but ex-Pramac Ducati rider Randy de Puniet posted impressive lap times while testing the 800cc GSV-R at Valencia. The Frenchman made clear he'd like to race the bike next year.
Suzuki last won the premier-class title with Kenny Roberts in 2000, but has taken just one race win - with Chris Vermeulen at a wet Le Mans in 2007 - during the four-stroke era. The team's most recent podium appearance was at Brno in 2008.
Should Suzuki withdraw it would reduce manufacturer participation in MotoGP to Honda, Ducati and Yamaha, although a new class of privateer 'Claiming Rule Teams' (CRTs) are being introduced to boost grid numbers for the start of the new 1000cc era in 2012.
The departure of Suzuki is also likely to send John Hopkins to World Superbike, alongside Leon Camier at Denning's Crescent Suzuki team.