In a press release today 2K Games and Firaxis announced:

"The Slingshot Content Pack, the first add-on content for the critically acclaimed XCOM : Enemy Unknown, is now available for purchase for Windows PC, the Xbox 360 video game and entertainment system from Microsoft and PlayStation 3 computer entertainment system. The Slingshot Content Pack is available for $6.99 (PlayStation Network) / 560 Microsoft Points (Xbox LIVE online entertainment network) / $6.99 (Windows PC).

With the Slingshot Content Pack, players will meet an enigmatic Triad operative, divert an alien ship's course, and do battle with the aliens in the skies over China in a new set of linked Council missions. The Slingshot Content Pack includes three new maps tied to the Council missions, a new playable squad character with a unique story and voice, and new character customization options."

UK Prices for PC and PS3 are likely to be around 4.99.