Coinciding with the twelfth anniversary of Counter-Strike Beta 1's release in 1999, Valve has announced it is working on a new title in the franchise, titled Counter-Strike: Global Offensive, or CS: GO.

Expanding upon the original's wildly successful team-based action gameplay, CS: GO will be a downloadable title targeted for release in early 2012 on Steam for PC and Mac, on Xbox Live Arcade and on PlayStation Network. It is being developed by Valve in cooperation with Seattle-based Hidden Path Entertainment.

CS: GO will introduce new gameplay modes, matchmaking, leader boards, "and more". Classic maps such as "de_dust" will return.

"Counter-Strike took the gaming industry by surprise when the unlikely MOD became the most played online PC action game in the world almost immediately after its release in August 1999," said Valve's Doug Lombardi. "For the past 12 years, it has continued to be one of the most-played games in the world, headline competitive gaming tournaments and selling over 25 million units worldwide across the franchise. CS: GO promises to expand on CS' award-winning gameplay and deliver it to gamers on the PC as well as the next gen consoles and the Mac."

Valve invited numerous top professional Counter-Strike players and representatives of the pro-gaming scene from around the world to its Seattle headquarters this past week for a "pre-beta" testing session to gauge player feedback on the new game. ESEA has a full write up.

Rumours of the new title first surfaced yesterday in a post on the Steam forums where it was mis-titled as "Counter-Strike: Global Operation". A reply by Counter-Strike co-creator Jess Cliff corrected the title, confirming the game's existence.

(Trivia: "Global Operations" is also the title of a Counter-Strike clone released in 2002 by Barking Dog Studios, the studio which was earlier contracted by Valve to develop the Beta 5 version of Counter-Strike and whose logo appears in the de_train map. Barking Dog Studios is now Rockstar Vancouver.)