The 'Earth' pack will add multiplayer maps set in Earth's cities, as well as new weapons and human classes, according to Reddit.
"The fighting is fiercest when it's your home at stake! Mass Effect 3™: Earth adds mods, gear, and new maps for Rio, Vancouver and London," read the leaked listing.
"It features three new weapons: Piranha assault shotgun, Acolyte pistol and Typhoon light machine gun. Six new human N7 classes are also available: Destroyer, Paladin, Demolisher, Slayer, Shadow, and Fury!"
Meanwhile, the previously-announced 'Extended Cut' pack has been confirmed to add an "extended epilogue" that elaborates the choices players have made.
"An expanded ending for Mass Effect 3. Additional scenes and an extended epilogue reveal the impact of Shepard's choices on the future of the galaxy."
The last DLC pack, 'Rebellion', was released last month as a free download.
Mass Effect 3 was confirmed to be coming to Wii U during last week's Nintendo press conference at E3.
> Read our review of 'Mass Effect 3'
Watch the 'Rebellion Pack' trailer for Mass Effect 3 below: