The controversial plan, which was announced in March, would result in AT&T paying $39 billion to acquire T-Mobile from its parent company Deutsche Telekom. AT&T touted the merger as a way to roll out Long Term Evolution (LTE) 4G networks to more customers and foster innovation. Some of its competitors and a few lawmakers have been more skeptical of the deal, while a group of customers have sued AT&T in an attempt to block the merger.
The Justice Department's complaint, filed in federal court today, says the merger would be a violation of U.S. antitrust law, a concern voiced by the aforementioned consumer-led lawsuit.
If it were to be approved, the merger would effectively result in a duopoly in the wireless industry, with AT&T and Verizon dominating the space and, some fear, leaving little room for competition and the interests of consumers.
"AT&T's elimination of T-Mobile as an independent, low- priced rival would remove a significant competitive force from the market," the U.S. filing said.