As part of the Metal Gear 20th anniversary celebrations Kojima Productions has formally announced the development of Metal Gear Solid: Portable Ops Plus.

The game is a follow-up to this year's award winning Metal Gear Solid: Portable Ops and will feature a focus on multiplayer gaming. The game aims to provide the definitive portable multiplayer experience, offering ad hoc and infrastructure wireless play with a host of new stages, characters and modes.

Plus will also include a brand-new single player mode: Infinity mission.

Metal Gear Solid: Portable Ops Plus is scheduled for release on PSP in 2008.