For hardcore gamers who read all the background material in the game books, you might recognize the UAC. The UAC is the fictional megacorp that is responsible for releasing Hell on Earth through the Doom franchise.
UAC is the largest and most powerful megacorporation in the Atlantic Federation. It began as a coalition of enterprises in the Military Industrial complex of the Commonwealth of New England where it made warships, aircraft, and spaceships. It expanded, building civilian ships and aircraft and power begets power. The UAC would grow to eventually 'purchase' the entire former state of New Jersey. Once this was done, the UAC became a proper Zaibatsu style megacorp and owned everything from the top of the Union Federation Credit Bank (UFCB) down to the quickie marts and sanitation reclamation zones.
Union Aerospace is the largest supplier of mechs, warships, firearms, power armors, and weapon systems in the world. It's goods are exported around the world, and off of earth to the colonies on the Moon, Mars, the Asteroid Belt, and beyond. It's creation of ion drive spacecraft, magnetic resonant shielding, and mass driver construction technologies have made it not just the most important megacorp to the Federation, but the entity singly most responsible for the rapid and mass colonization of space.
Aside from owning the former state of New Jersey, the UAC (always 'the' never just) also has legal ownership of both of Mars' moons, Phobos and Deimos, as well as owning no fewer than 13 asteroids that have been moved into earth orbit, mined out, and rebuilt as some of the best offworld real estate in the solar system.
UAC is a leader in space exploration, space exploration technologies and offworld resource gathering efforts. It has mining operations throughout the asteroid belt, on Mars, and major construction efforts at the LaGrange points and on the moon. It is the second largest employer in the Atlantic Federation (only surpassed by the Federation government and military)
The UAC was a founding member of the New Economic Bloc Treaty Organization (NEBTO) which has promoted human cloning, downgraded human rights in various nations, and promoted militarism as an effective model of economic growth.
The UAC has also been a primary supporter of the Federation Corporate Party in the government. While the Commonwealth of New England has remained in largely in the hands of the American Socialist Party, the Corporate Party has made major inroads against the establishment, as well as all but conquering the neighboring Great Lakes Republic (via Omni-Consumer Products). This party, while not really that attractive, has lots and lots of money and money talks.
The UAC has two hideous secrets. It has been actively pursuing pointless skirmishes and low level wars between the Federation and other smaller powers to maintain its pro-military stance. No on buys tanks unless there is a war on. The ongoing hostilities in Africa between Congo (AF) and the South African United Republics (SAUR) have been egged on and incited in several instances by UAC runners. Likewise conflicts in MesoAmerica, the Levant, and the Kingdom of Scandinavia.
Secondly, the UAC has been doing a lot of black budget work with arcanotechnology. They are messing with things that are patently beyond the ken of mankind. They have accidentally created several 'storm surges' that have resulted in cosmic horrors, zombie outbreaks, and mutations that they have worked diligently to cover up, research and exploit, and weaponize. If a single world power was going to wipe out humanity for doing something stupid, it will likely come from a UAC letterhead.