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The merger between the telecommunications giants T-Mobile and Sprint is in jeopardy. 

Department of Justice staff recommends the deal, which would form a $146 billion company to take on Verizon and AT&T, be blocked, according to Reuters. Still, the DOJ is up to a month away from making a final ruling, the report said. 

The agreement, which involves T-Mobile exchanging 9.75 Sprint shares per unit of T-Mobile, would join the third- and fourth-largest US wireless providers, giving them a combined 127 million customers. That would make it the No. 3 carrier behind Verizon and AT&T.

Deutsche Telekom would own 42% of the combined company, while SoftBank, which controls 85% of Sprint, would own 27%. The public would hold the remaining 31%.

The deal was expected to face antitrust opposition from the start. The Trump administration put up a fierce defense against the $85 billion deal between AT&T and Time Warner before it was finally approved after the companies were able to reach an agreement with regulators.  

This story is developing. Check back for updates.