The multiplayer DLC will release as a free download on May 29, for PlayStation 3 in North America as well as Xbox 360 and PC worldwide. It will be available on May 30 on PlayStation 3 in Europe.
Consistent with the leak earlier this month, the Rebellion pack will include six new characters, three weapons and two maps for multiplayer.
New character classes include the male Quarian Engineer and Infiltrator, Vorcha Soldier and Sentinel, and Ex-Cerberus Vanguard and Adept.
New map Firebase Goddess takes the action to the Asari home planet of Thessia, while Firebase Jade is set against the backdrop of a jungle reservoir. Players will also have access to the new Cerberus Harrier Assault Rifle, Reegar Carbine Shotgun and Krysae Sniper Rifle weapons.
A new mission objective will also be added to all maps, requiring players to escort a high priority package to a designated secure zone.
Finally, a new equipment slot will be available, allowing players to equip items to offer a permanent boost in addition to the existing single-use items.
Mass Effect 3's 'Resurgence Pack' was offered for free when it launched last month. It similarly contained a selection of new maps, classes and weapons.
Mass Effect 3 has been heavily criticised for its ending. BioWare has announced that it will release a free Extended Cut DLC pack to "clarify" the ending with additional cinematic sequences this summer.
> Read our review of Mass Effect 3
Watch the trailer for Mass Effect 3 below: