The U.S. Department of Justice's antitrust division may file a lawsuit to block T-Mobile's $1.35 billion acquisition of Mint Mobile, sources have told the New York Post, on the grounds that it is anticompetitive. On March 15, T-Mobile US (NASDAQ: TMUS) announced that it had acquired the Ka'ena Corporation and its subsidiaries: Mint Mobile, a prepaid wireless brand; Ultra Mobile, a wireless service offering international calling; and wholesaler Plum, Inside Towers reported. "T-Mobile is acquiring the brands' sales, marketing, digital, and service operations, and plans to use its supplier relationships and distribution scale to help the brands to grow and offer competitive pricing and greater device inventory to more U.S. consumers seeking value offerings," T-Mobile said when the acquisition was announced. The Mint and Ultra brands are complementary to T-Mobile's current prepaid service offerings Metro by T-Mobile, T-Mobile branded prepaid and Connect by T-Mobile, it said.