Sierra has confirmed that its forthcoming third-person open-world game Prototype has been delayed until next year.

In a statement the publisher said: "Sierra Entertainment and Radical Entertainment have made the decision to shift Prototype to launch in 2009.

"Since its announcement, Prototype has been regarded by many as groundbreaking and taking the open-world genre in new directions, and in the simplest explanation possible, we need more time to deliver the game the team initially set out to create."

In development for PC, PS3 and Xbox 360, Prototype was originally given a summer 2008 release date when it was announced last year.

The game came into problems with Australian and German rating authorities more recently with regards to its violence levels, forcing the publishers to make heavily-edited versions for these markets.

However, Sierra have reassured gamers: "Date changes are common in this industry, especially for publishers and developers committed to launching great games."

No details have been announced as to when we can expect the game in 2009 but Sierra has promised there would be an announcement closer to the time.