WorldComFor a time, WorldCom (WCOM) was the United States' second largest long distance phone company (AT&T is the largest). WorldCom grew largely by acquiring other telecommunications companies, most notably MCI. It also owned the Tier 1 ISP UUNET, a major part of the Internet backbone. It was based in Clinton, Mississippi.
In June, 2002, an internal audit discovered that US$3.8 billion had been 'misaccounted.' The US Securities and Exchange Commission launched an investigation into these matters on June 26, 2002 (See accounting scandals).
In August, 2002, an additional $3.3 billion in improper accounting since 1999 was announced.
In light of these accounting scandals, the company has changed its name back to MCI.
In May, 2003, the company was given a no-bid contract by the United States Department of Defense to build a cellular telephone network in Iraq. The deal has been criticized by competitors and others who cite the company's lack of experience in the area.