Activision on Thursday announced that Annihilation, the third piece of downloadable content pack of Call of Duty: Black Ops will be available for Xbox 360 on June 28. The pack will be available for PS3 and PC a month later.

The game is available for Microsoft Windows, Xbox 360, PlayStation 3, and Wii consoles.

Call of Duty: Black Ops is a first-person shooter video game developed by Treyarch and published by Activision. Black Ops is the seventh installment of the Call of Duty series, and the first to be set in the Cold War and the fifth to be set in World War II.The game is available for Microsoft Windows, Xbox 360, PlayStation 3, and Wii consoles.

Black Ops sold more than 7 million copies within 24 hours of its release in November last year, and passed the $1 billion mark in sales for Activision within six weeks of its release. Fuelled only by so called content updates, it continues to stay in the top ten video games sold each month. Black Ops continues to draw millions of gamers online globally, logging billions of gameplay hours since its launch in November. Black Ops is the best selling game ever on the Xbox 360.

With the breakthrough First Strike and Escalation content packs, the blockbuster title is also already the highest selling add-on content in Xbox LIVE history, according to Microsoft.

The newest offering, Annihilation, will launch first on Xbox LIVE and features four new multiplayer maps and a Zombie experience that's sure to keep gamers coming back for more.

"With Annihilation, Black Ops fans will get four exciting and unique multiplayer settings with Hangar 18, Drive-In, Silo and Hazard," said Treyarch Studio Head, Mark Lamia. "Players will also enjoy an all-new Zombies experience, Shangri-La, an exotic and mysterious map filled with deadly traps, dark secrets and innovative gameplay that will challenge even the most daring Zombie hunters."

Escalation, the second content pack for Black Ops, was only made available on the PlayStation 3 computer entertainment system on June 10. Escalation features four new multiplayer maps and an unprecedented Zombie experience, including famed director George A. Romero, Robert Englund, Sarah Michelle Gellar, Michael Rooker and Danny Trejo, as well as an original music track from Avenged Sevenfold titled "Not Ready to Die." Escalation can be downloaded for US$14.99 from the PlayStation Store.

Call of Duty: Black Ops is rated "M" (Mature) by the ESRB for Blood and Gore, Intense Violence and Strong Language.

Black Ops' successor, Call of Duty: Modern Warfare 3, is expected to be released in November this year.